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As starting point add vlan id and rss hash if xdp metadata is supported.

Add xd_metadata_support field in VSI to allow easy passing this value to
ring configuration.

Signed-off-by: Michal Swiatkowski michal.swiatkowski@intel.com

As starting point add vlan id and rss hash if xdp metadata is supported.

Add xd_metadata_support field in VSI to allow easy passing this value to
ring configuration.

Signed-off-by: Michal Swiatkowski <michal.swiatkowski@intel.com>
@mswiatko mswiatko merged this pull request into generic-metadata Aug 10, 2021
@mswiatko mswiatko deleted the generic-metadata-ice-support branch August 10, 2021 11:03
alobakin pushed a commit that referenced this pull request Sep 13, 2021
When removing the driver module w/o bringing an interface up before
the error below occurs. Reason seems to be that cancel_work_sync() is
called in t3_sge_stop() for a queue that hasn't been initialized yet.

[10085.941785] ------------[ cut here ]------------
[10085.941799] WARNING: CPU: 1 PID: 5850 at kernel/workqueue.c:3074 __flush_work+0x3ff/0x480
[10085.941819] Modules linked in: vfat snd_hda_codec_hdmi fat snd_hda_codec_realtek snd_hda_codec_generic ledtrig_audio led_class ee1004 iTCO_
wdt intel_tcc_cooling x86_pkg_temp_thermal coretemp aesni_intel crypto_simd cryptd snd_hda_intel snd_intel_dspcfg snd_hda_codec snd_hda_core r
8169 snd_pcm realtek mdio_devres snd_timer snd i2c_i801 i2c_smbus libphy i915 i2c_algo_bit cxgb3(-) intel_gtt ttm mdio drm_kms_helper mei_me s
yscopyarea sysfillrect sysimgblt mei fb_sys_fops acpi_pad sch_fq_codel crypto_user drm efivarfs ext4 mbcache jbd2 crc32c_intel
[10085.941944] CPU: 1 PID: 5850 Comm: rmmod Not tainted 5.14.0-rc7-next-20210826+ #6
[10085.941974] Hardware name: System manufacturer System Product Name/PRIME H310I-PLUS, BIOS 2603 10/21/2019
[10085.941992] RIP: 0010:__flush_work+0x3ff/0x480
[10085.942003] Code: c0 74 6b 65 ff 0d d1 bd 78 75 e8 bc 2f 06 00 48 c7 c6 68 b1 88 8a 48 c7 c7 e0 5f b4 8b 45 31 ff e8 e6 66 04 00 e9 4b fe ff ff <0f> 0b 45 31 ff e9 41 fe ff ff e8 72 c1 79 00 85 c0 74 87 80 3d 22
[10085.942036] RSP: 0018:ffffa1744383fc08 EFLAGS: 00010246
[10085.942048] RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000923
[10085.942062] RDX: 0000000000000000 RSI: 0000000000000001 RDI: ffff91c901710a88
[10085.942076] RBP: ffffa1744383fce8 R08: 0000000000000001 R09: 0000000000000001
[10085.942090] R10: 00000000000000c2 R11: 0000000000000000 R12: ffff91c901710a88
[10085.942104] R13: 0000000000000000 R14: ffff91c909a96100 R15: 0000000000000001
[10085.942118] FS:  00007fe417837740(0000) GS:ffff91c969d00000(0000) knlGS:0000000000000000
[10085.942134] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[10085.942146] CR2: 000055a8d567ecd8 CR3: 0000000121690003 CR4: 00000000003706e0
[10085.942160] Call Trace:
[10085.942166]  ? __lock_acquire+0x3af/0x22e0
[10085.942177]  ? cancel_work_sync+0xb/0x10
[10085.942187]  __cancel_work_timer+0x128/0x1b0
[10085.942197]  ? __pm_runtime_resume+0x5b/0x90
[10085.942208]  cancel_work_sync+0xb/0x10
[10085.942217]  t3_sge_stop+0x2f/0x50 [cxgb3]
[10085.942234]  remove_one+0x26/0x190 [cxgb3]
[10085.942248]  pci_device_remove+0x39/0xa0
[10085.942258]  __device_release_driver+0x15e/0x240
[10085.942269]  driver_detach+0xd9/0x120
[10085.942278]  bus_remove_driver+0x53/0xd0
[10085.942288]  driver_unregister+0x2c/0x50
[10085.942298]  pci_unregister_driver+0x31/0x90
[10085.942307]  cxgb3_cleanup_module+0x10/0x18c [cxgb3]
[10085.942324]  __do_sys_delete_module+0x191/0x250
[10085.942336]  ? syscall_enter_from_user_mode+0x21/0x60
[10085.942347]  ? trace_hardirqs_on+0x2a/0xe0
[10085.942357]  __x64_sys_delete_module+0x13/0x20
[10085.942368]  do_syscall_64+0x40/0x90
[10085.942377]  entry_SYSCALL_64_after_hwframe+0x44/0xae
[10085.942389] RIP: 0033:0x7fe41796323b

Fixes: 5e0b892 ("net:cxgb3: replace tasklets with works")
Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
alobakin pushed a commit that referenced this pull request Sep 13, 2021
If CONFIG_BLK_DEV_LOOP && CONFIG_MTD (at least; there might be other
combinations), lockdep complains circular locking dependency at
__loop_clr_fd(), for major_names_lock serves as a locking dependency
aggregating hub across multiple block modules.

 ======================================================
 WARNING: possible circular locking dependency detected
 5.14.0+ torvalds#757 Tainted: G            E
 ------------------------------------------------------
 systemd-udevd/7568 is trying to acquire lock:
 ffff88800f334d48 ((wq_completion)loop0){+.+.}-{0:0}, at: flush_workqueue+0x70/0x560

 but task is already holding lock:
 ffff888014a7d4a0 (&lo->lo_mutex){+.+.}-{3:3}, at: __loop_clr_fd+0x4d/0x400 [loop]

 which lock already depends on the new lock.

 the existing dependency chain (in reverse order) is:

 -> #6 (&lo->lo_mutex){+.+.}-{3:3}:
        lock_acquire+0xbe/0x1f0
        __mutex_lock_common+0xb6/0xe10
        mutex_lock_killable_nested+0x17/0x20
        lo_open+0x23/0x50 [loop]
        blkdev_get_by_dev+0x199/0x540
        blkdev_open+0x58/0x90
        do_dentry_open+0x144/0x3a0
        path_openat+0xa57/0xda0
        do_filp_open+0x9f/0x140
        do_sys_openat2+0x71/0x150
        __x64_sys_openat+0x78/0xa0
        do_syscall_64+0x3d/0xb0
        entry_SYSCALL_64_after_hwframe+0x44/0xae

 -> #5 (&disk->open_mutex){+.+.}-{3:3}:
        lock_acquire+0xbe/0x1f0
        __mutex_lock_common+0xb6/0xe10
        mutex_lock_nested+0x17/0x20
        bd_register_pending_holders+0x20/0x100
        device_add_disk+0x1ae/0x390
        loop_add+0x29c/0x2d0 [loop]
        blk_request_module+0x5a/0xb0
        blkdev_get_no_open+0x27/0xa0
        blkdev_get_by_dev+0x5f/0x540
        blkdev_open+0x58/0x90
        do_dentry_open+0x144/0x3a0
        path_openat+0xa57/0xda0
        do_filp_open+0x9f/0x140
        do_sys_openat2+0x71/0x150
        __x64_sys_openat+0x78/0xa0
        do_syscall_64+0x3d/0xb0
        entry_SYSCALL_64_after_hwframe+0x44/0xae

 -> #4 (major_names_lock){+.+.}-{3:3}:
        lock_acquire+0xbe/0x1f0
        __mutex_lock_common+0xb6/0xe10
        mutex_lock_nested+0x17/0x20
        blkdev_show+0x19/0x80
        devinfo_show+0x52/0x60
        seq_read_iter+0x2d5/0x3e0
        proc_reg_read_iter+0x41/0x80
        vfs_read+0x2ac/0x330
        ksys_read+0x6b/0xd0
        do_syscall_64+0x3d/0xb0
        entry_SYSCALL_64_after_hwframe+0x44/0xae

 -> #3 (&p->lock){+.+.}-{3:3}:
        lock_acquire+0xbe/0x1f0
        __mutex_lock_common+0xb6/0xe10
        mutex_lock_nested+0x17/0x20
        seq_read_iter+0x37/0x3e0
        generic_file_splice_read+0xf3/0x170
        splice_direct_to_actor+0x14e/0x350
        do_splice_direct+0x84/0xd0
        do_sendfile+0x263/0x430
        __se_sys_sendfile64+0x96/0xc0
        do_syscall_64+0x3d/0xb0
        entry_SYSCALL_64_after_hwframe+0x44/0xae

 -> #2 (sb_writers#3){.+.+}-{0:0}:
        lock_acquire+0xbe/0x1f0
        lo_write_bvec+0x96/0x280 [loop]
        loop_process_work+0xa68/0xc10 [loop]
        process_one_work+0x293/0x480
        worker_thread+0x23d/0x4b0
        kthread+0x163/0x180
        ret_from_fork+0x1f/0x30

 -> #1 ((work_completion)(&lo->rootcg_work)){+.+.}-{0:0}:
        lock_acquire+0xbe/0x1f0
        process_one_work+0x280/0x480
        worker_thread+0x23d/0x4b0
        kthread+0x163/0x180
        ret_from_fork+0x1f/0x30

 -> #0 ((wq_completion)loop0){+.+.}-{0:0}:
        validate_chain+0x1f0d/0x33e0
        __lock_acquire+0x92d/0x1030
        lock_acquire+0xbe/0x1f0
        flush_workqueue+0x8c/0x560
        drain_workqueue+0x80/0x140
        destroy_workqueue+0x47/0x4f0
        __loop_clr_fd+0xb4/0x400 [loop]
        blkdev_put+0x14a/0x1d0
        blkdev_close+0x1c/0x20
        __fput+0xfd/0x220
        task_work_run+0x69/0xc0
        exit_to_user_mode_prepare+0x1ce/0x1f0
        syscall_exit_to_user_mode+0x26/0x60
        do_syscall_64+0x4c/0xb0
        entry_SYSCALL_64_after_hwframe+0x44/0xae

 other info that might help us debug this:

 Chain exists of:
   (wq_completion)loop0 --> &disk->open_mutex --> &lo->lo_mutex

  Possible unsafe locking scenario:

        CPU0                    CPU1
        ----                    ----
   lock(&lo->lo_mutex);
                                lock(&disk->open_mutex);
                                lock(&lo->lo_mutex);
   lock((wq_completion)loop0);

  *** DEADLOCK ***

 2 locks held by systemd-udevd/7568:
  #0: ffff888012554128 (&disk->open_mutex){+.+.}-{3:3}, at: blkdev_put+0x4c/0x1d0
  #1: ffff888014a7d4a0 (&lo->lo_mutex){+.+.}-{3:3}, at: __loop_clr_fd+0x4d/0x400 [loop]

 stack backtrace:
 CPU: 0 PID: 7568 Comm: systemd-udevd Tainted: G            E     5.14.0+ torvalds#757
 Hardware name: VMware, Inc. VMware Virtual Platform/440BX Desktop Reference Platform, BIOS 6.00 02/27/2020
 Call Trace:
  dump_stack_lvl+0x79/0xbf
  print_circular_bug+0x5d6/0x5e0
  ? stack_trace_save+0x42/0x60
  ? save_trace+0x3d/0x2d0
  check_noncircular+0x10b/0x120
  validate_chain+0x1f0d/0x33e0
  ? __lock_acquire+0x953/0x1030
  ? __lock_acquire+0x953/0x1030
  __lock_acquire+0x92d/0x1030
  ? flush_workqueue+0x70/0x560
  lock_acquire+0xbe/0x1f0
  ? flush_workqueue+0x70/0x560
  flush_workqueue+0x8c/0x560
  ? flush_workqueue+0x70/0x560
  ? sched_clock_cpu+0xe/0x1a0
  ? drain_workqueue+0x41/0x140
  drain_workqueue+0x80/0x140
  destroy_workqueue+0x47/0x4f0
  ? blk_mq_freeze_queue_wait+0xac/0xd0
  __loop_clr_fd+0xb4/0x400 [loop]
  ? __mutex_unlock_slowpath+0x35/0x230
  blkdev_put+0x14a/0x1d0
  blkdev_close+0x1c/0x20
  __fput+0xfd/0x220
  task_work_run+0x69/0xc0
  exit_to_user_mode_prepare+0x1ce/0x1f0
  syscall_exit_to_user_mode+0x26/0x60
  do_syscall_64+0x4c/0xb0
  entry_SYSCALL_64_after_hwframe+0x44/0xae
 RIP: 0033:0x7f0fd4c661f7
 Code: 00 00 f7 d8 64 89 02 48 c7 c0 ff ff ff ff eb b7 0f 1f 00 f3 0f 1e fa 64 8b 04 25 18 00 00 00 85 c0 75 10 b8 03 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 41 c3 48 83 ec 18 89 7c 24 0c e8 13 fc ff ff
 RSP: 002b:00007ffd1c9e9fd8 EFLAGS: 00000246 ORIG_RAX: 0000000000000003
 RAX: 0000000000000000 RBX: 00007f0fd46be6c8 RCX: 00007f0fd4c661f7
 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000006
 RBP: 0000000000000006 R08: 000055fff1eaf400 R09: 0000000000000000
 R10: 00007f0fd46be6c8 R11: 0000000000000246 R12: 0000000000000000
 R13: 0000000000000000 R14: 0000000000002f08 R15: 00007ffd1c9ea050

Commit 1c500ad ("loop: reduce the loop_ctl_mutex scope") is for
breaking "loop_ctl_mutex => &lo->lo_mutex" dependency chain. But enabling
a different block module results in forming circular locking dependency
due to shared major_names_lock mutex.

The simplest fix is to call probe function without holding
major_names_lock [1], but Christoph Hellwig does not like such idea.
Therefore, instead of holding major_names_lock in blkdev_show(),
introduce a different lock for blkdev_show() in order to break
"sb_writers#$N => &p->lock => major_names_lock" dependency chain.

Link: https://lkml.kernel.org/r/b2af8a5b-3c1b-204e-7f56-bea0b15848d6@i-love.sakura.ne.jp [1]
Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Link: https://lore.kernel.org/r/18a02da2-0bf3-550e-b071-2b4ab13c49f0@i-love.sakura.ne.jp
Signed-off-by: Jens Axboe <axboe@kernel.dk>
alobakin pushed a commit that referenced this pull request Sep 23, 2021
It's later supposed to be either a correct address or NULL. Without the
initialization, it may contain an undefined value which results in the
following segmentation fault:

  # perf top --sort comm -g --ignore-callees=do_idle

terminates with:

  #0  0x00007ffff56b7685 in __strlen_avx2 () from /lib64/libc.so.6
  #1  0x00007ffff55e3802 in strdup () from /lib64/libc.so.6
  #2  0x00005555558cb139 in hist_entry__init (callchain_size=<optimized out>, sample_self=true, template=0x7fffde7fb110, he=0x7fffd801c250) at util/hist.c:489
  #3  hist_entry__new (template=template@entry=0x7fffde7fb110, sample_self=sample_self@entry=true) at util/hist.c:564
  #4  0x00005555558cb4ba in hists__findnew_entry (hists=hists@entry=0x5555561d9e38, entry=entry@entry=0x7fffde7fb110, al=al@entry=0x7fffde7fb420,
      sample_self=sample_self@entry=true) at util/hist.c:657
  #5  0x00005555558cba1b in __hists__add_entry (hists=hists@entry=0x5555561d9e38, al=0x7fffde7fb420, sym_parent=<optimized out>, bi=bi@entry=0x0, mi=mi@entry=0x0,
      sample=sample@entry=0x7fffde7fb4b0, sample_self=true, ops=0x0, block_info=0x0) at util/hist.c:288
  #6  0x00005555558cbb70 in hists__add_entry (sample_self=true, sample=0x7fffde7fb4b0, mi=0x0, bi=0x0, sym_parent=<optimized out>, al=<optimized out>, hists=0x5555561d9e38)
      at util/hist.c:1056
  #7  iter_add_single_cumulative_entry (iter=0x7fffde7fb460, al=<optimized out>) at util/hist.c:1056
  #8  0x00005555558cc8a4 in hist_entry_iter__add (iter=iter@entry=0x7fffde7fb460, al=al@entry=0x7fffde7fb420, max_stack_depth=<optimized out>, arg=arg@entry=0x7fffffff7db0)
      at util/hist.c:1231
  #9  0x00005555557cdc9a in perf_event__process_sample (machine=<optimized out>, sample=0x7fffde7fb4b0, evsel=<optimized out>, event=<optimized out>, tool=0x7fffffff7db0)
      at builtin-top.c:842
  #10 deliver_event (qe=<optimized out>, qevent=<optimized out>) at builtin-top.c:1202
  #11 0x00005555558a9318 in do_flush (show_progress=false, oe=0x7fffffff80e0) at util/ordered-events.c:244
  #12 __ordered_events__flush (oe=oe@entry=0x7fffffff80e0, how=how@entry=OE_FLUSH__TOP, timestamp=timestamp@entry=0) at util/ordered-events.c:323
  #13 0x00005555558a9789 in __ordered_events__flush (timestamp=<optimized out>, how=<optimized out>, oe=<optimized out>) at util/ordered-events.c:339
  #14 ordered_events__flush (how=OE_FLUSH__TOP, oe=0x7fffffff80e0) at util/ordered-events.c:341
  #15 ordered_events__flush (oe=oe@entry=0x7fffffff80e0, how=how@entry=OE_FLUSH__TOP) at util/ordered-events.c:339
  #16 0x00005555557cd631 in process_thread (arg=0x7fffffff7db0) at builtin-top.c:1114
  #17 0x00007ffff7bb817a in start_thread () from /lib64/libpthread.so.0
  #18 0x00007ffff5656dc3 in clone () from /lib64/libc.so.6

If you look at the frame #2, the code is:

488	 if (he->srcline) {
489          he->srcline = strdup(he->srcline);
490          if (he->srcline == NULL)
491              goto err_rawdata;
492	 }

If he->srcline is not NULL (it is not NULL if it is uninitialized rubbish),
it gets strdupped and strdupping a rubbish random string causes the problem.

Also, if you look at the commit 1fb7d06, it adds the srcline property
into the struct, but not initializing it everywhere needed.

Committer notes:

Now I see, when using --ignore-callees=do_idle we end up here at line
2189 in add_callchain_ip():

2181         if (al.sym != NULL) {
2182                 if (perf_hpp_list.parent && !*parent &&
2183                     symbol__match_regex(al.sym, &parent_regex))
2184                         *parent = al.sym;
2185                 else if (have_ignore_callees && root_al &&
2186                   symbol__match_regex(al.sym, &ignore_callees_regex)) {
2187                         /* Treat this symbol as the root,
2188                            forgetting its callees. */
2189                         *root_al = al;
2190                         callchain_cursor_reset(cursor);
2191                 }
2192         }

And the al that doesn't have the ->srcline field initialized will be
copied to the root_al, so then, back to:

1211 int hist_entry_iter__add(struct hist_entry_iter *iter, struct addr_location *al,
1212                          int max_stack_depth, void *arg)
1213 {
1214         int err, err2;
1215         struct map *alm = NULL;
1216
1217         if (al)
1218                 alm = map__get(al->map);
1219
1220         err = sample__resolve_callchain(iter->sample, &callchain_cursor, &iter->parent,
1221                                         iter->evsel, al, max_stack_depth);
1222         if (err) {
1223                 map__put(alm);
1224                 return err;
1225         }
1226
1227         err = iter->ops->prepare_entry(iter, al);
1228         if (err)
1229                 goto out;
1230
1231         err = iter->ops->add_single_entry(iter, al);
1232         if (err)
1233                 goto out;
1234

That al at line 1221 is what hist_entry_iter__add() (called from
sample__resolve_callchain()) saw as 'root_al', and then:

        iter->ops->add_single_entry(iter, al);

will go on with al->srcline with a bogus value, I'll add the above
sequence to the cset and apply, thanks!

Signed-off-by: Michael Petlan <mpetlan@redhat.com>
CC: Milian Wolff <milian.wolff@kdab.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Fixes: 1fb7d06 ("perf report Use srcline from callchain for hist entries")
Link: https //lore.kernel.org/r/20210719145332.29747-1-mpetlan@redhat.com
Reported-by: Juri Lelli <jlelli@redhat.com>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
alobakin pushed a commit that referenced this pull request Sep 23, 2021
FD uses xyarray__entry that may return NULL if an index is out of
bounds. If NULL is returned then a segv happens as FD unconditionally
dereferences the pointer. This was happening in a case of with perf
iostat as shown below. The fix is to make FD an "int*" rather than an
int and handle the NULL case as either invalid input or a closed fd.

  $ sudo gdb --args perf stat --iostat  list
  ...
  Breakpoint 1, perf_evsel__alloc_fd (evsel=0x5555560951a0, ncpus=1, nthreads=1) at evsel.c:50
  50      {
  (gdb) bt
   #0  perf_evsel__alloc_fd (evsel=0x5555560951a0, ncpus=1, nthreads=1) at evsel.c:50
   #1  0x000055555585c188 in evsel__open_cpu (evsel=0x5555560951a0, cpus=0x555556093410,
      threads=0x555556086fb0, start_cpu=0, end_cpu=1) at util/evsel.c:1792
   #2  0x000055555585cfb2 in evsel__open (evsel=0x5555560951a0, cpus=0x0, threads=0x555556086fb0)
      at util/evsel.c:2045
   #3  0x000055555585d0db in evsel__open_per_thread (evsel=0x5555560951a0, threads=0x555556086fb0)
      at util/evsel.c:2065
   #4  0x00005555558ece64 in create_perf_stat_counter (evsel=0x5555560951a0,
      config=0x555555c34700 <stat_config>, target=0x555555c2f1c0 <target>, cpu=0) at util/stat.c:590
   #5  0x000055555578e927 in __run_perf_stat (argc=1, argv=0x7fffffffe4a0, run_idx=0)
      at builtin-stat.c:833
   #6  0x000055555578f3c6 in run_perf_stat (argc=1, argv=0x7fffffffe4a0, run_idx=0)
      at builtin-stat.c:1048
   #7  0x0000555555792ee5 in cmd_stat (argc=1, argv=0x7fffffffe4a0) at builtin-stat.c:2534
   #8  0x0000555555835ed3 in run_builtin (p=0x555555c3f540 <commands+288>, argc=3,
      argv=0x7fffffffe4a0) at perf.c:313
   #9  0x0000555555836154 in handle_internal_command (argc=3, argv=0x7fffffffe4a0) at perf.c:365
   #10 0x000055555583629f in run_argv (argcp=0x7fffffffe2ec, argv=0x7fffffffe2e0) at perf.c:409
   #11 0x0000555555836692 in main (argc=3, argv=0x7fffffffe4a0) at perf.c:539
  ...
  (gdb) c
  Continuing.
  Error:
  The sys_perf_event_open() syscall returned with 22 (Invalid argument) for event (uncore_iio_0/event=0x83,umask=0x04,ch_mask=0xF,fc_mask=0x07/).
  /bin/dmesg | grep -i perf may provide additional information.

  Program received signal SIGSEGV, Segmentation fault.
  0x00005555559b03ea in perf_evsel__close_fd_cpu (evsel=0x5555560951a0, cpu=1) at evsel.c:166
  166                     if (FD(evsel, cpu, thread) >= 0)

v3. fixes a bug in perf_evsel__run_ioctl where the sense of a branch was
    backward.

Signed-off-by: Ian Rogers <irogers@google.com>
Acked-by: Jiri Olsa <jolsa@redhat.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lore.kernel.org/lkml/20210918054440.2350466-1-irogers@google.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
alobakin pushed a commit that referenced this pull request Oct 1, 2021
Ido Schimmel says:

====================
mlxsw: Add support for transceiver modules reset

This patchset prepares mlxsw for future transceiver modules related [1]
changes and adds reset support via the existing 'ETHTOOL_RESET'
interface.

Patches #1-#6 are relatively straightforward preparations.

Patch #7 tracks the number of logical ports that are mapped to the
transceiver module and the number of logical ports using it that are
administratively up. Needed for both reset support and power mode policy
support.

Patches #8-#9 add required fields in device registers.

Patch #10 implements support for ethtool_ops::reset in order to reset
transceiver modules.

[1] https://lore.kernel.org/netdev/20210824130344.1828076-1-idosch@idosch.org/
====================

Signed-off-by: David S. Miller <davem@davemloft.net>
alobakin pushed a commit that referenced this pull request Oct 1, 2021
Ido Schimmel says:

====================
mlxsw: Add support for IP-in-IP with IPv6 underlay

Currently, mlxsw only supports IP-in-IP with IPv4 underlay. Traffic
routed through 'gre' netdevs is encapsulated with IPv4 and GRE headers.
Similarly, incoming IPv4 GRE packets are decapsulated and routed in the
overlay VRF (which can be the same as the underlay VRF).

This patchset adds support for IPv6 underlay using the 'ip6gre' netdev.
Due to architectural differences between Spectrum-1 and later ASICs,
this functionality is only supported on Spectrum-2 onwards (the software
data path is used for Spectrum-1).

Patchset overview:

Patches #1-#5 are preparations.

Patches #6-#9 add and extend required device registers.

Patches #10-#14 gradually add IPv6 underlay support.

A follow-up patchset will add net/forwarding/ selftests.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>
alobakin pushed a commit that referenced this pull request Oct 7, 2021
Biju Das says:

====================
Fillup stubs for Gigabit Ethernet driver support

The DMAC and EMAC blocks of Gigabit Ethernet IP found on RZ/G2L SoC are
similar to the R-Car Ethernet AVB IP.

The Gigabit Ethernet IP consists of Ethernet controller (E-MAC), Internal
TCP/IP Offload Engine (TOE)  and Dedicated Direct memory access controller
(DMAC).

With a few changes in the driver we can support both IPs.

This patch series is for adding Gigabit ethernet driver support to RZ/G2L SoC.

The number of patches after incorporatng RFC review comments is 18.
So split the patches into 2 patchsets (10 + 8).

This series is the second patchset, aims to fillup all the stubs for the
Gigabit Ethernet driver.

This patch series depend upon [1]
[1] https://lore.kernel.org/linux-renesas-soc/20211001150636.7500-1-biju.das.jz@bp.renesas.com/T/#t

RFC->V1:
 * used rx_max_buf_size instead of rx_2k_buffers feature bit.
 * renamed "rgeth" to "gbeth".
 * renamed ravb_rx_ring_free to ravb_rx_ring_free_rcar
 * renamed ravb_rx_ring_format to ravb_rx_ring_format_rcar
 * renamed ravb_alloc_rx_desc to ravb_alloc_rx_desc_rcar
 * renamed ravb_rcar_rx to ravb_rx_rcar
 * Added Sergey's Rb tag for patch #6.
 * Moved CSR0 initialization to patch #8.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>
alobakin pushed a commit that referenced this pull request Oct 7, 2021
…r-mode'

Ido Schimmel says:

====================
ethtool: Add ability to control transceiver modules' power mode

This patchset extends the ethtool netlink API to allow user space to
control transceiver modules. Two specific APIs are added, but the plan
is to extend the interface with more APIs in the future (see "Future
plans").

This submission is a complete rework of a previous submission [1] that
tried to achieve the same goal by allowing user space to write to the
EEPROMs of these modules. It was rejected as it could have enabled user
space binary blob drivers.

However, the main issue is that by directly writing to some pages of
these EEPROMs, we are interfering with the entity that is controlling
the modules (kernel / device firmware). In addition, some functionality
cannot be implemented solely by writing to the EEPROM, as it requires
the assertion / de-assertion of hardware signals (e.g., "ResetL" pin in
SFF-8636).

Motivation
==========

The kernel can currently dump the contents of module EEPROMs to user
space via the ethtool legacy ioctl API or the new netlink API. These
dumps can then be parsed by ethtool(8) according to the specification
that defines the memory map of the EEPROM. For example, SFF-8636 [2] for
QSFP and CMIS [3] for QSFP-DD.

In addition to read-only elements, these specifications also define
writeable elements that can be used to control the behavior of the
module. For example, controlling whether the module is put in low or
high power mode to limit its power consumption.

The CMIS specification even defines a message exchange mechanism (CDB,
Command Data Block) on top of the module's memory map. This allows the
host to send various commands to the module. For example, to update its
firmware.

Implementation
==============

The ethtool netlink API is extended with two new messages,
'ETHTOOL_MSG_MODULE_SET' and 'ETHTOOL_MSG_MODULE_GET', that allow user
space to set and get transceiver module parameters. Specifically, the
'ETHTOOL_A_MODULE_POWER_MODE_POLICY' attribute allows user space to
control the power mode policy of the module in order to limit its power
consumption. See detailed description in patch #1.

The user API is designed to be generic enough so that it could be used
for modules with different memory maps (e.g., SFF-8636, CMIS).

The only implementation of the device driver API in this series is for a
MAC driver (mlxsw) where the module is controlled by the device's
firmware, but it is designed to be generic enough so that it could also
be used by implementations where the module is controlled by the kernel.

Testing and introspection
=========================

See detailed description in patches #1 and #5.

Patchset overview
=================

Patch #1 adds the initial infrastructure in ethtool along with the
ability to control transceiver modules' power mode.

Patches #2-#3 add required device registers in mlxsw.

Patch #4 implements in mlxsw the ethtool operations added in patch #1.

Patch #5 adds extended link states in order to allow user space to
troubleshoot link down issues related to transceiver modules.

Patch #6 adds support for these extended states in mlxsw.

Future plans
============

* Extend 'ETHTOOL_MSG_MODULE_SET' to control Tx output among other
attributes.

* Add new ethtool message(s) to update firmware on transceiver modules.

* Extend ethtool(8) to parse more diagnostic information from CMIS
modules. No kernel changes required.

[1] https://lore.kernel.org/netdev/20210623075925.2610908-1-idosch@idosch.org/
[2] https://members.snia.org/document/dl/26418
[3] http://www.qsfp-dd.com/wp-content/uploads/2021/05/CMIS5p0.pdf

Previous versions:
[4] https://lore.kernel.org/netdev/20211003073219.1631064-1-idosch@idosch.org/
[5] https://lore.kernel.org/netdev/20210824130344.1828076-1-idosch@idosch.org/
[6] https://lore.kernel.org/netdev/20210818155202.1278177-1-idosch@idosch.org/
[7] https://lore.kernel.org/netdev/20210809102152.719961-1-idosch@idosch.org/
====================

Link: https://lore.kernel.org/r/20211006104647.2357115-1-idosch@idosch.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
alobakin pushed a commit that referenced this pull request Oct 11, 2021
Ido Schimmel says:

====================
selftests: forwarding: Add ip6gre tests

This patchset adds forwarding selftests for ip6gre. The tests can be run
with veth pairs or with physical loopbacks.

Patch #1 adds a new config option to determine if 'skip_sw' / 'skip_hw'
flags are used when installing tc filters. By default, it is not set
which means the flags are not used. 'skip_sw' is useful to ensure
traffic is forwarded by the hardware data path.

Patch #2 adds a new helper function.

Patches #3-#4 add the forwarding selftests.

Patch #5 adds a mlxsw-specific selftest to validate correct behavior of
the 'decap_error' trap with IPv6 underlay.

Patches #6-#8 align the corresponding IPv4 underlay test to the IPv6
one.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>
alobakin pushed a commit that referenced this pull request Oct 14, 2021
Ido Schimmel says:

====================
mlxsw: Add support for ECN mirroring

Petr says:

Patches in this set have been floating around for some time now together
with trap_fwd support. That will however need more work, time for which is
nowhere to be found, apparently. Instead, this patchset enables offload of
only packet mirroring on RED mark qevent, enabling mirroring of ECN-marked
packets.

Formally it enables offload of filters added to blocks bound to the RED
qevent mark if:

- The switch ASIC is Spectrum-2 or above.
- Only a single filter is attached at the block, at chain 0 (the default),
  and its classifier is matchall.
- The filter has hw_stats set to disabled.
- The filter has a single action, which is mirror.

This differs from early_drop qevent offload, which supports mirroring and
trapping. However trapping in context of ECN-marked packets is not
suitable, because the HW does not drop the packet, as the trap action
implies. And there is as of now no way to express only the part of trapping
that transfers the packet to the SW datapath, sans the HW-datapath drop.

The patchset progresses as follows:

Patch #1 is an extack propagation.

Mirroring of ECN-marked packets is configured in the ASIC through an ECN
trigger, which is considered "egress", unlike the EARLY_DROP trigger.
In patch #2, add a helper to classify triggers as ingress.

As clarified above, traps cannot be offloaded on mark qevent. Similarly,
given a trap_fwd action, it would not be offloadable on early_drop qevent.
In patch #3, introduce support for tracking actions permissible on a given
block.

Patch #4 actually adds the mark qevent offload.

In patch #5, fix a small style issue in one of the selftests, and in
patch #6 add mark offload selftests.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>
alobakin pushed a commit that referenced this pull request Oct 20, 2021
Ido Schimmel says:

====================
mlxsw: Multi-level qdisc offload

Petr says:

Currently, mlxsw admits for offload a suitable root qdisc, and its
children. Thus up to two levels of hierarchy are offloaded. Often, this is
enough: one can configure TCs with RED and TCs with a shaper on, and can
even see counters for each TC by looking at a qdisc at a sufficiently
shallow position.

While simple, the system has obvious shortcomings. It is not possible to
configure both RED and shaping on one TC. It is not possible to place a
PRIO below root TBF, which would then be offloaded as port shaper. FIFOs
are only offloaded at root or directly below, which is confusing to users,
because RED and TBF of course have their own FIFO.

This patch set lifts assumptions that prevent offloading multi-level qdisc
trees.

In patch #1, offload of a graft operation is added to TBF. Grafts are
issued as another qdisc is linked to the qdisc in question, and give
drivers a chance to react to the linking. The absence of this event was not
a major issue so far, because TBF was not considered classful, which
changes with this patchset.

The codebase currently assumes that ETS and PRIO are the only classful
qdiscs. The following patches gradually lift this assumption.

In patch #2, calculation of traffic class and priomap of a qdisc is fixed.

Patch #3 fixes handling of future FIFOs. Child FIFO qdiscs may be created
and notified before their parent qdisc exists and therefore need special
handling.

Patches #4, #5 and #6 unify, respectively, child destruction, child
grafting, and cleanup of statistics.

Patch #7 adds a function that validates whether a given qdisc topology is
offloadable.

Finally in patch #8, TBF and RED become classful. At this point, FIFO
qdiscs grafted to an offloaded qdisc should always be offloaded.

Patch #9 adds a selftest to verify some offloadable and unoffloadable qdisc
trees.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>
alobakin pushed a commit that referenced this pull request Oct 29, 2021
Ido Schimmel says:

====================
mlxsw: Support multiple RIF MAC prefixes

Currently, mlxsw enforces that all the netdevs used as router interfaces
(RIFs) have the same MAC prefix (e.g., same 38 MSBs in Spectrum-1).
Otherwise, an error is returned to user space with extack. This patchset
relaxes the limitation through the use of RIF MAC profiles.

A RIF MAC profile is a hardware entity that represents a particular MAC
prefix which multiple RIFs can reference. Therefore, the number of
possible MAC prefixes is no longer one, but the number of profiles
supported by the device.

The ability to change the MAC of a particular netdev is useful, for
example, for users who use the netdev to connect to an upstream provider
that performs MAC filtering. Currently, such users are either forced to
negotiate with the provider or change the MAC address of all other
netdevs so that they share the same prefix.

Patchset overview:

Patches #1-#3 are preparations.

Patch #4 adds actual support for RIF MAC profiles.

Patch #5 exposes RIF MAC profiles as a devlink resource, so that user
space has visibility into the maximum number of profiles and current
occupancy. Useful for debugging and testing (next 3 patches).

Patches #6-#8 add both scale and functional tests.

Patch #9 removes tests that validated the previous limitation. It is now
covered by patch #6 for devices that support a single profile.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>
alobakin pushed a commit that referenced this pull request Nov 3, 2021
Attempting to defragment a Btrfs file containing a transparent huge page
immediately deadlocks with the following stack trace:

  #0  context_switch (kernel/sched/core.c:4940:2)
  #1  __schedule (kernel/sched/core.c:6287:8)
  #2  schedule (kernel/sched/core.c:6366:3)
  #3  io_schedule (kernel/sched/core.c:8389:2)
  #4  wait_on_page_bit_common (mm/filemap.c:1356:4)
  #5  __lock_page (mm/filemap.c:1648:2)
  #6  lock_page (./include/linux/pagemap.h:625:3)
  #7  pagecache_get_page (mm/filemap.c:1910:4)
  #8  find_or_create_page (./include/linux/pagemap.h:420:9)
  #9  defrag_prepare_one_page (fs/btrfs/ioctl.c:1068:9)
  #10 defrag_one_range (fs/btrfs/ioctl.c:1326:14)
  #11 defrag_one_cluster (fs/btrfs/ioctl.c:1421:9)
  #12 btrfs_defrag_file (fs/btrfs/ioctl.c:1523:9)
  #13 btrfs_ioctl_defrag (fs/btrfs/ioctl.c:3117:9)
  #14 btrfs_ioctl (fs/btrfs/ioctl.c:4872:10)
  #15 vfs_ioctl (fs/ioctl.c:51:10)
  #16 __do_sys_ioctl (fs/ioctl.c:874:11)
  #17 __se_sys_ioctl (fs/ioctl.c:860:1)
  #18 __x64_sys_ioctl (fs/ioctl.c:860:1)
  #19 do_syscall_x64 (arch/x86/entry/common.c:50:14)
  #20 do_syscall_64 (arch/x86/entry/common.c:80:7)
  #21 entry_SYSCALL_64+0x7c/0x15b (arch/x86/entry/entry_64.S:113)

A huge page is represented by a compound page, which consists of a
struct page for each PAGE_SIZE page within the huge page. The first
struct page is the "head page", and the remaining are "tail pages".

Defragmentation attempts to lock each page in the range. However,
lock_page() on a tail page actually locks the corresponding head page.
So, if defragmentation tries to lock more than one struct page in a
compound page, it tries to lock the same head page twice and deadlocks
with itself.

Ideally, we should be able to defragment transparent huge pages.
However, THP for filesystems is currently read-only, so a lot of code is
not ready to use huge pages for I/O. For now, let's just return
ETXTBUSY.

This can be reproduced with the following on a kernel with
CONFIG_READ_ONLY_THP_FOR_FS=y:

  $ cat create_thp_file.c
  #include <fcntl.h>
  #include <stdbool.h>
  #include <stdio.h>
  #include <stdint.h>
  #include <stdlib.h>
  #include <unistd.h>
  #include <sys/mman.h>

  static const char zeroes[1024 * 1024];
  static const size_t FILE_SIZE = 2 * 1024 * 1024;

  int main(int argc, char **argv)
  {
          if (argc != 2) {
                  fprintf(stderr, "usage: %s PATH\n", argv[0]);
                  return EXIT_FAILURE;
          }
          int fd = creat(argv[1], 0777);
          if (fd == -1) {
                  perror("creat");
                  return EXIT_FAILURE;
          }
          size_t written = 0;
          while (written < FILE_SIZE) {
                  ssize_t ret = write(fd, zeroes,
                                      sizeof(zeroes) < FILE_SIZE - written ?
                                      sizeof(zeroes) : FILE_SIZE - written);
                  if (ret < 0) {
                          perror("write");
                          return EXIT_FAILURE;
                  }
                  written += ret;
          }
          close(fd);
          fd = open(argv[1], O_RDONLY);
          if (fd == -1) {
                  perror("open");
                  return EXIT_FAILURE;
          }

          /*
           * Reserve some address space so that we can align the file mapping to
           * the huge page size.
           */
          void *placeholder_map = mmap(NULL, FILE_SIZE * 2, PROT_NONE,
                                       MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
          if (placeholder_map == MAP_FAILED) {
                  perror("mmap (placeholder)");
                  return EXIT_FAILURE;
          }

          void *aligned_address =
                  (void *)(((uintptr_t)placeholder_map + FILE_SIZE - 1) & ~(FILE_SIZE - 1));

          void *map = mmap(aligned_address, FILE_SIZE, PROT_READ | PROT_EXEC,
                           MAP_SHARED | MAP_FIXED, fd, 0);
          if (map == MAP_FAILED) {
                  perror("mmap");
                  return EXIT_FAILURE;
          }
          if (madvise(map, FILE_SIZE, MADV_HUGEPAGE) < 0) {
                  perror("madvise");
                  return EXIT_FAILURE;
          }

          char *line = NULL;
          size_t line_capacity = 0;
          FILE *smaps_file = fopen("/proc/self/smaps", "r");
          if (!smaps_file) {
                  perror("fopen");
                  return EXIT_FAILURE;
          }
          for (;;) {
                  for (size_t off = 0; off < FILE_SIZE; off += 4096)
                          ((volatile char *)map)[off];

                  ssize_t ret;
                  bool this_mapping = false;
                  while ((ret = getline(&line, &line_capacity, smaps_file)) > 0) {
                          unsigned long start, end, huge;
                          if (sscanf(line, "%lx-%lx", &start, &end) == 2) {
                                  this_mapping = (start <= (uintptr_t)map &&
                                                  (uintptr_t)map < end);
                          } else if (this_mapping &&
                                     sscanf(line, "FilePmdMapped: %ld", &huge) == 1 &&
                                     huge > 0) {
                                  return EXIT_SUCCESS;
                          }
                  }

                  sleep(6);
                  rewind(smaps_file);
                  fflush(smaps_file);
          }
  }
  $ ./create_thp_file huge
  $ btrfs fi defrag -czstd ./huge

Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Omar Sandoval <osandov@fb.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
alobakin pushed a commit that referenced this pull request Nov 3, 2021
After commit 9298e63 ("bpf/tests: Add exhaustive tests of ALU
operand magnitudes"), when modprobe test_bpf.ko with JIT on mips64,
there exists segment fault due to the following reason:

  [...]
  ALU64_MOV_X: all register value magnitudes jited:1
  Break instruction in kernel code[#1]
  [...]

It seems that the related JIT implementations of some test cases
in test_bpf() have problems. At this moment, I do not care about
the segment fault while I just want to verify the test cases of
tail calls.

Based on the above background and motivation, add the following
module parameter test_suite to the test_bpf.ko:

  test_suite=<string>: only the specified test suite will be run, the
  string can be "test_bpf", "test_tail_calls" or "test_skb_segment".

If test_suite is not specified, but test_id, test_name or test_range
is specified, set 'test_bpf' as the default test suite. This is useful
to only test the corresponding test suite when specifying the valid
test_suite string.

Any invalid test suite will result in -EINVAL being returned and no
tests being run. If the test_suite is not specified or specified as
empty string, it does not change the current logic, all of the test
cases will be run.

Here are some test results:

 # dmesg -c
 # modprobe test_bpf
 # dmesg | grep Summary
 test_bpf: Summary: 1009 PASSED, 0 FAILED, [0/997 JIT'ed]
 test_bpf: test_tail_calls: Summary: 8 PASSED, 0 FAILED, [0/8 JIT'ed]
 test_bpf: test_skb_segment: Summary: 2 PASSED, 0 FAILED

 # rmmod test_bpf
 # dmesg -c
 # modprobe test_bpf test_suite=test_bpf
 # dmesg | tail -1
 test_bpf: Summary: 1009 PASSED, 0 FAILED, [0/997 JIT'ed]

 # rmmod test_bpf
 # dmesg -c
 # modprobe test_bpf test_suite=test_tail_calls
 # dmesg
 test_bpf: #0 Tail call leaf jited:0 21 PASS
 [...]
 test_bpf: #7 Tail call error path, index out of range jited:0 32 PASS
 test_bpf: test_tail_calls: Summary: 8 PASSED, 0 FAILED, [0/8 JIT'ed]

 # rmmod test_bpf
 # dmesg -c
 # modprobe test_bpf test_suite=test_skb_segment
 # dmesg
 test_bpf: #0 gso_with_rx_frags PASS
 test_bpf: #1 gso_linear_no_head_frag PASS
 test_bpf: test_skb_segment: Summary: 2 PASSED, 0 FAILED

 # rmmod test_bpf
 # dmesg -c
 # modprobe test_bpf test_id=1
 # dmesg
 test_bpf: test_bpf: set 'test_bpf' as the default test_suite.
 test_bpf: #1 TXA jited:0 54 51 50 PASS
 test_bpf: Summary: 1 PASSED, 0 FAILED, [0/1 JIT'ed]

 # rmmod test_bpf
 # dmesg -c
 # modprobe test_bpf test_suite=test_bpf test_name=TXA
 # dmesg
 test_bpf: #1 TXA jited:0 54 50 51 PASS
 test_bpf: Summary: 1 PASSED, 0 FAILED, [0/1 JIT'ed]

 # rmmod test_bpf
 # dmesg -c
 # modprobe test_bpf test_suite=test_tail_calls test_range=6,7
 # dmesg
 test_bpf: #6 Tail call error path, NULL target jited:0 41 PASS
 test_bpf: #7 Tail call error path, index out of range jited:0 32 PASS
 test_bpf: test_tail_calls: Summary: 2 PASSED, 0 FAILED, [0/2 JIT'ed]

 # rmmod test_bpf
 # dmesg -c
 # modprobe test_bpf test_suite=test_skb_segment test_id=1
 # dmesg
 test_bpf: #1 gso_linear_no_head_frag PASS
 test_bpf: test_skb_segment: Summary: 1 PASSED, 0 FAILED

By the way, the above segment fault has been fixed in the latest bpf-next
tree which contains the mips64 JIT rework.

Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Tested-by: Johan Almbladh <johan.almbladh@anyfinetworks.com>
Acked-by: Johan Almbladh <johan.almbladh@anyfinetworks.com>
Link: https://lore.kernel.org/bpf/1635384321-28128-1-git-send-email-yangtiezhu@loongson.cn
alobakin pushed a commit that referenced this pull request Nov 23, 2021
The exit function fixes a memory leak with the src field as detected by
leak sanitizer. An example of which is:

Indirect leak of 25133184 byte(s) in 207 object(s) allocated from:
    #0 0x7f199ecfe987 in __interceptor_calloc libsanitizer/asan/asan_malloc_linux.cpp:154
    #1 0x55defe638224 in annotated_source__alloc_histograms util/annotate.c:803
    #2 0x55defe6397e4 in symbol__hists util/annotate.c:952
    #3 0x55defe639908 in symbol__inc_addr_samples util/annotate.c:968
    #4 0x55defe63aa29 in hist_entry__inc_addr_samples util/annotate.c:1119
    #5 0x55defe499a79 in hist_iter__report_callback tools/perf/builtin-report.c:182
    #6 0x55defe7a859d in hist_entry_iter__add util/hist.c:1236
    #7 0x55defe49aa63 in process_sample_event tools/perf/builtin-report.c:315
    #8 0x55defe731bc8 in evlist__deliver_sample util/session.c:1473
    #9 0x55defe731e38 in machines__deliver_event util/session.c:1510
    #10 0x55defe732a23 in perf_session__deliver_event util/session.c:1590
    #11 0x55defe72951e in ordered_events__deliver_event util/session.c:183
    #12 0x55defe740082 in do_flush util/ordered-events.c:244
    #13 0x55defe7407cb in __ordered_events__flush util/ordered-events.c:323
    #14 0x55defe740a61 in ordered_events__flush util/ordered-events.c:341
    #15 0x55defe73837f in __perf_session__process_events util/session.c:2390
    #16 0x55defe7385ff in perf_session__process_events util/session.c:2420
    ...

Signed-off-by: Ian Rogers <irogers@google.com>
Acked-by: Namhyung Kim <namhyung@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: James Clark <james.clark@arm.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Kajol Jain <kjain@linux.ibm.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Martin Liška <mliska@suse.cz>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: https://lore.kernel.org/r/20211112035124.94327-3-irogers@google.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
alobakin pushed a commit that referenced this pull request Nov 30, 2021
To clear a user buffer we cannot simply use memset, we have to use
clear_user().  With a virtio-mem device that registers a vmcore_cb and
has some logically unplugged memory inside an added Linux memory block,
I can easily trigger a BUG by copying the vmcore via "cp":

  systemd[1]: Starting Kdump Vmcore Save Service...
  kdump[420]: Kdump is using the default log level(3).
  kdump[453]: saving to /sysroot/var/crash/127.0.0.1-2021-11-11-14:59:22/
  kdump[458]: saving vmcore-dmesg.txt to /sysroot/var/crash/127.0.0.1-2021-11-11-14:59:22/
  kdump[465]: saving vmcore-dmesg.txt complete
  kdump[467]: saving vmcore
  BUG: unable to handle page fault for address: 00007f2374e01000
  #PF: supervisor write access in kernel mode
  #PF: error_code(0x0003) - permissions violation
  PGD 7a523067 P4D 7a523067 PUD 7a528067 PMD 7a525067 PTE 800000007048f867
  Oops: 0003 [#1] PREEMPT SMP NOPTI
  CPU: 0 PID: 468 Comm: cp Not tainted 5.15.0+ #6
  Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.14.0-27-g64f37cc530f1-prebuilt.qemu.org 04/01/2014
  RIP: 0010:read_from_oldmem.part.0.cold+0x1d/0x86
  Code: ff ff ff e8 05 ff fe ff e9 b9 e9 7f ff 48 89 de 48 c7 c7 38 3b 60 82 e8 f1 fe fe ff 83 fd 08 72 3c 49 8d 7d 08 4c 89 e9 89 e8 <49> c7 45 00 00 00 00 00 49 c7 44 05 f8 00 00 00 00 48 83 e7 f81
  RSP: 0018:ffffc9000073be08 EFLAGS: 00010212
  RAX: 0000000000001000 RBX: 00000000002fd000 RCX: 00007f2374e01000
  RDX: 0000000000000001 RSI: 00000000ffffdfff RDI: 00007f2374e01008
  RBP: 0000000000001000 R08: 0000000000000000 R09: ffffc9000073bc50
  R10: ffffc9000073bc48 R11: ffffffff829461a8 R12: 000000000000f000
  R13: 00007f2374e01000 R14: 0000000000000000 R15: ffff88807bd421e8
  FS:  00007f2374e12140(0000) GS:ffff88807f000000(0000) knlGS:0000000000000000
  CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
  CR2: 00007f2374e01000 CR3: 000000007a4aa000 CR4: 0000000000350eb0
  Call Trace:
   read_vmcore+0x236/0x2c0
   proc_reg_read+0x55/0xa0
   vfs_read+0x95/0x190
   ksys_read+0x4f/0xc0
   do_syscall_64+0x3b/0x90
   entry_SYSCALL_64_after_hwframe+0x44/0xae

Some x86-64 CPUs have a CPU feature called "Supervisor Mode Access
Prevention (SMAP)", which is used to detect wrong access from the kernel
to user buffers like this: SMAP triggers a permissions violation on
wrong access.  In the x86-64 variant of clear_user(), SMAP is properly
handled via clac()+stac().

To fix, properly use clear_user() when we're dealing with a user buffer.

Link: https://lkml.kernel.org/r/20211112092750.6921-1-david@redhat.com
Fixes: 997c136 ("fs/proc/vmcore.c: add hook to read_from_oldmem() to check for non-ram pages")
Signed-off-by: David Hildenbrand <david@redhat.com>
Acked-by: Baoquan He <bhe@redhat.com>
Cc: Dave Young <dyoung@redhat.com>
Cc: Baoquan He <bhe@redhat.com>
Cc: Vivek Goyal <vgoyal@redhat.com>
Cc: Philipp Rudo <prudo@redhat.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
alobakin pushed a commit that referenced this pull request Dec 22, 2021
The fixed commit attempts to close inject.output even if it was never
opened e.g.

  $ perf record uname
  Linux
  [ perf record: Woken up 1 times to write data ]
  [ perf record: Captured and wrote 0.002 MB perf.data (7 samples) ]
  $ perf inject -i perf.data --vm-time-correlation=dry-run
  Segmentation fault (core dumped)
  $ gdb --quiet perf
  Reading symbols from perf...
  (gdb) r inject -i perf.data --vm-time-correlation=dry-run
  Starting program: /home/ahunter/bin/perf inject -i perf.data --vm-time-correlation=dry-run
  [Thread debugging using libthread_db enabled]
  Using host libthread_db library "/lib/x86_64-linux-gnu/libthread_db.so.1".

  Program received signal SIGSEGV, Segmentation fault.
  0x00007eff8afeef5b in _IO_new_fclose (fp=0x0) at iofclose.c:48
  48      iofclose.c: No such file or directory.
  (gdb) bt
  #0  0x00007eff8afeef5b in _IO_new_fclose (fp=0x0) at iofclose.c:48
  #1  0x0000557fc7b74f92 in perf_data__close (data=data@entry=0x7ffcdafa6578) at util/data.c:376
  #2  0x0000557fc7a6b807 in cmd_inject (argc=<optimized out>, argv=<optimized out>) at builtin-inject.c:1085
  #3  0x0000557fc7ac4783 in run_builtin (p=0x557fc8074878 <commands+600>, argc=4, argv=0x7ffcdafb6a60) at perf.c:313
  #4  0x0000557fc7a25d5c in handle_internal_command (argv=<optimized out>, argc=<optimized out>) at perf.c:365
  #5  run_argv (argcp=<optimized out>, argv=<optimized out>) at perf.c:409
  #6  main (argc=4, argv=0x7ffcdafb6a60) at perf.c:539
  (gdb)

Fixes: 02e6246 ("perf inject: Close inject.output on exit")
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Riccardo Mancini <rickyman7@gmail.com>
Cc: stable@vger.kernel.org
Link: http://lore.kernel.org/lkml/20211213084829.114772-2-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
alobakin pushed a commit that referenced this pull request Dec 22, 2021
The fixed commit attempts to get the output file descriptor even if the
file was never opened e.g.

  $ perf record uname
  Linux
  [ perf record: Woken up 1 times to write data ]
  [ perf record: Captured and wrote 0.002 MB perf.data (7 samples) ]
  $ perf inject -i perf.data --vm-time-correlation=dry-run
  Segmentation fault (core dumped)
  $ gdb --quiet perf
  Reading symbols from perf...
  (gdb) r inject -i perf.data --vm-time-correlation=dry-run
  Starting program: /home/ahunter/bin/perf inject -i perf.data --vm-time-correlation=dry-run
  [Thread debugging using libthread_db enabled]
  Using host libthread_db library "/lib/x86_64-linux-gnu/libthread_db.so.1".

  Program received signal SIGSEGV, Segmentation fault.
  __GI___fileno (fp=0x0) at fileno.c:35
  35      fileno.c: No such file or directory.
  (gdb) bt
  #0  __GI___fileno (fp=0x0) at fileno.c:35
  #1  0x00005621e48dd987 in perf_data__fd (data=0x7fff4c68bd08) at util/data.h:72
  #2  perf_data__fd (data=0x7fff4c68bd08) at util/data.h:69
  #3  cmd_inject (argc=<optimized out>, argv=0x7fff4c69c1f0) at builtin-inject.c:1017
  #4  0x00005621e4936783 in run_builtin (p=0x5621e4ee6878 <commands+600>, argc=4, argv=0x7fff4c69c1f0) at perf.c:313
  #5  0x00005621e4897d5c in handle_internal_command (argv=<optimized out>, argc=<optimized out>) at perf.c:365
  #6  run_argv (argcp=<optimized out>, argv=<optimized out>) at perf.c:409
  #7  main (argc=4, argv=0x7fff4c69c1f0) at perf.c:539
  (gdb)

Fixes: 0ae0389 ("perf tools: Pass a fd to perf_file_header__read_pipe()")
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Riccardo Mancini <rickyman7@gmail.com>
Cc: stable@vger.kernel.org
Link: http://lore.kernel.org/lkml/20211213084829.114772-3-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
alobakin pushed a commit that referenced this pull request Jan 3, 2022
Ido Schimmel says:

====================
mlxsw: Add support for VxLAN with IPv6 underlay

So far, mlxsw only supported VxLAN with IPv4 underlay. This patchset
extends mlxsw to also support VxLAN with IPv6 underlay. The main
difference is related to the way IPv6 addresses are handled by the
device. See patch #1 for a detailed explanation.

Patch #1 creates a common hash table to store the mapping from IPv6
addresses to KVDL indexes. This table is useful for both IP-in-IP and
VxLAN tunnels with an IPv6 underlay.

Patch #2 converts the IP-in-IP code to use the new hash table.

Patches #3-#6 are preparations.

Patch #7 finally adds support for VxLAN with IPv6 underlay.

Patch #8 removes a test case that checked that VxLAN configurations with
IPv6 underlay are vetoed by the driver.

A follow-up patchset will add forwarding selftests.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>
alobakin pushed a commit that referenced this pull request Jan 3, 2022
In line:
	upper = info->upper_dev;
We access upper_dev field, which is related only for particular events
(e.g. event == NETDEV_CHANGEUPPER). So, this line cause invalid memory
access for another events,
when ptr is not netdev_notifier_changeupper_info.

The KASAN logs are as follows:

[   30.123165] BUG: KASAN: stack-out-of-bounds in prestera_netdev_port_event.constprop.0+0x68/0x538 [prestera]
[   30.133336] Read of size 8 at addr ffff80000cf772b0 by task udevd/778
[   30.139866]
[   30.141398] CPU: 0 PID: 778 Comm: udevd Not tainted 5.16.0-rc3 #6
[   30.147588] Hardware name: DNI AmazonGo1 A7040 board (DT)
[   30.153056] Call trace:
[   30.155547]  dump_backtrace+0x0/0x2c0
[   30.159320]  show_stack+0x18/0x30
[   30.162729]  dump_stack_lvl+0x68/0x84
[   30.166491]  print_address_description.constprop.0+0x74/0x2b8
[   30.172346]  kasan_report+0x1e8/0x250
[   30.176102]  __asan_load8+0x98/0xe0
[   30.179682]  prestera_netdev_port_event.constprop.0+0x68/0x538 [prestera]
[   30.186847]  prestera_netdev_event_handler+0x1b4/0x1c0 [prestera]
[   30.193313]  raw_notifier_call_chain+0x74/0xa0
[   30.197860]  call_netdevice_notifiers_info+0x68/0xc0
[   30.202924]  register_netdevice+0x3cc/0x760
[   30.207190]  register_netdev+0x24/0x50
[   30.211015]  prestera_device_register+0x8a0/0xba0 [prestera]

Fixes: 3d5048c ("net: marvell: prestera: move netdev topology validation to prestera_main")
Signed-off-by: Yevhen Orlov <yevhen.orlov@plvision.eu>
Link: https://lore.kernel.org/r/20211216171714.11341-1-yevhen.orlov@plvision.eu
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
alobakin pushed a commit that referenced this pull request Jan 3, 2022
Amit Cohen says:

====================
Add tests for VxLAN with IPv6 underlay

mlxsw driver lately added support for VxLAN with IPv6 underlay.
This set adds the relevant tests for IPv6, most of them are same to
IPv4 tests with the required changes.

Patch set overview:
Patch #1 relaxes requirements for offloading TC filters that
match on 802.1q fields. The following selftests make use of these
newly-relaxed filters.
Patch #2 adds preparation as part of selftests API, which will be used
later.
Patches #3-#4 add tests for VxLAN with bridge aware and unaware.
Patche #5 cleans unused function.
Patches #6-#7 add tests for VxLAN symmetric and asymmetric.
Patch #8 adds test for Q-in-VNI.
====================

Link: https://lore.kernel.org/r/20211221144949.2527545-1-amcohen@nvidia.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
alobakin pushed a commit that referenced this pull request Jan 3, 2022
Amit Cohen says:

====================
mlxsw: Add tests for VxLAN with IPv6 underlay

mlxsw driver lately added support for VxLAN with IPv6 underlay.
This set adds tests for IPv6, which are dedicated for mlxsw.

Patch set overview:
Patches #1-#2 make vxlan.sh test more flexible and extend it for IPv6
Patches #3-#4 make vxlan_fdb_veto.sh test more flexible and extend it
for IPv6
Patches #5-#6 add tests for VxLAN flooding for different ASICs
Patches #7-#8 add test for VxLAN related traps and align the existing
test
====================

Signed-off-by: David S. Miller <davem@davemloft.net>
alobakin pushed a commit that referenced this pull request Jan 10, 2022
Ido Schimmel says:

====================
mlxsw: Add Spectrum-4 support

This patchset adds Spectrum-4 support in mlxsw. It builds on top of a
previous patchset merged in commit 10184da ("Merge branch
'mlxsw-Spectrum-4-prep'") and makes two additional changes before adding
Spectrum-4 support.

Patchset overview:

Patches #1-#2 add a few Spectrum-4 specific variants of existing ACL
keys. The new variants are needed because the size of certain key
elements (e.g., local port) was increased in Spectrum-4.

Patches #3-#6 are preparations.

Patch #7 implements the Spectrum-4 variant of the Bloom filter hash
function. The Bloom filter is used to optimize ACL lookups by
potentially skipping certain lookups if they are guaranteed not to
match. See additional info in merge commit ae6750e ("Merge branch
'mlxsw-spectrum_acl-Add-Bloom-filter-support'").

Patch #8 finally adds Spectrum-4 support.
====================

Link: https://lore.kernel.org/r/20220106160652.821176-1-idosch@nvidia.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
walking-machine pushed a commit that referenced this pull request Mar 10, 2022
Ido Schimmel says:

====================
mlxsw: Add RJ45 ports support

We are in the process of qualifying a new system that has RJ45 ports as
opposed to the transceiver modules (e.g., SFP, QSFP) present on all
existing systems.

This patchset adds support for these ports in mlxsw by adding a couple of
missing BaseT link modes and rejecting ethtool operations that are
specific to transceiver modules.

Patchset overview:

Patches #1-#3 are cleanups and preparations.

Patch #4 adds support for two new link modes.

Patches #5-#6 query and cache the port module's type (e.g., QSFP, RJ45)
during initialization.

Patches #7-#9 forbid ethtool operations that are invalid on RJ45 ports.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>
walking-machine pushed a commit that referenced this pull request Mar 10, 2022
Ido Schimmel says:

====================
mlxsw: Various updates

This patchset contains miscellaneous updates for mlxsw. No user visible
changes that I am aware of.

Patches #1-#5 rework registration of internal traps in preparation of
line cards support.

Patch #6 improves driver resilience against a misbehaving device.

Patch #7 prevents the driver from overwriting device internal actions.
See the commit message for more details.
====================

Link: https://lore.kernel.org/r/20220127090226.283442-1-idosch@nvidia.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
walking-machine pushed a commit that referenced this pull request Mar 10, 2022
Dust Li says:

====================
net/smc: some datapath performance optimizations

This series tries to improve the performance of SMC in datapath.

- patch #1, add sysctl interface to support tuning the behaviour of
  SMC in container environment.

- patch #2/#3, add autocorking support which is very efficient for small
  messages without trade-off for latency.

- patch #4, send directly on setting TCP_NODELAY, without wake up the
  TX worker, this make it consistent with clearing TCP_CORK.

- patch #5, this correct the setting of RMB window update limit, so
  we don't send CDC messages to update peer's RMB window too frequently
  in some cases.

- patch #6, implemented something like NAPI in SMC, decrease the number
  of hardirq when busy.

- patch #7, this moves TX work doing in the BH to the user context when
  sock_lock is hold by user.

With this patchset applied, we can get a good performance gain:
- qperf tcp_bw test has shown a great improvement. Other benchmarks like
  'netperf TCP_STREAM' or 'sockperf throughput' has similar result.
- In my testing environment, running qperf tcp_bw and tcp_lat, SMC behaves
  better then TCP in most all message size.

Here are some test results with the following testing command:
client: smc_run taskset -c 1 qperf smc-server -oo msg_size:1:64K:*2 \
		-t 30 -vu tcp_{bw|lat}
server: smc_run taskset -c 1 qperf

==== Bandwidth ====
 MsgSize        Origin SMC              TCP                SMC with patches
       1         0.578 MB/s      2.392 MB/s(313.57%)      2.561 MB/s(342.83%)
       2         1.159 MB/s      4.780 MB/s(312.53%)      5.162 MB/s(345.46%)
       4         2.283 MB/s     10.266 MB/s(349.77%)     10.122 MB/s(343.46%)
       8         4.668 MB/s     19.040 MB/s(307.86%)     20.521 MB/s(339.59%)
      16         9.147 MB/s     38.904 MB/s(325.31%)     40.823 MB/s(346.29%)
      32        18.369 MB/s     79.587 MB/s(333.25%)     80.535 MB/s(338.42%)
      64        36.562 MB/s    148.668 MB/s(306.61%)    158.170 MB/s(332.60%)
     128        72.961 MB/s    274.913 MB/s(276.80%)    316.217 MB/s(333.41%)
     256       144.705 MB/s    512.059 MB/s(253.86%)    626.019 MB/s(332.62%)
     512       288.873 MB/s    884.977 MB/s(206.35%)   1221.596 MB/s(322.88%)
    1024       574.180 MB/s   1337.736 MB/s(132.98%)   2203.156 MB/s(283.70%)
    2048      1095.192 MB/s   1865.952 MB/s( 70.38%)   3036.448 MB/s(177.25%)
    4096      2066.157 MB/s   2380.337 MB/s( 15.21%)   3834.271 MB/s( 85.58%)
    8192      3717.198 MB/s   2733.073 MB/s(-26.47%)   4904.910 MB/s( 31.95%)
   16384      4742.221 MB/s   2958.693 MB/s(-37.61%)   5220.272 MB/s( 10.08%)
   32768      5349.550 MB/s   3061.285 MB/s(-42.77%)   5321.865 MB/s( -0.52%)
   65536      5162.919 MB/s   3731.408 MB/s(-27.73%)   5245.021 MB/s(  1.59%)
==== Latency ====
 MsgSize        Origin SMC              TCP                SMC with patches
       1        10.540 us     11.938 us( 13.26%)         10.356 us( -1.75%)
       2        10.996 us     11.992 us(  9.06%)         10.073 us( -8.39%)
       4        10.229 us     11.687 us( 14.25%)          9.996 us( -2.28%)
       8        10.203 us     11.653 us( 14.21%)         10.063 us( -1.37%)
      16        10.530 us     11.313 us(  7.44%)         10.013 us( -4.91%)
      32        10.241 us     11.586 us( 13.13%)         10.081 us( -1.56%)
      64        10.693 us     11.652 us(  8.97%)          9.986 us( -6.61%)
     128        10.597 us     11.579 us(  9.27%)         10.262 us( -3.16%)
     256        10.409 us     11.957 us( 14.87%)         10.148 us( -2.51%)
     512        11.088 us     12.505 us( 12.78%)         10.206 us( -7.95%)
    1024        11.240 us     12.255 us(  9.03%)         10.631 us( -5.42%)
    2048        11.485 us     16.970 us( 47.76%)         10.981 us( -4.39%)
    4096        12.077 us     13.948 us( 15.49%)         11.847 us( -1.90%)
    8192        13.683 us     16.693 us( 22.00%)         13.336 us( -2.54%)
   16384        16.470 us     23.615 us( 43.38%)         16.519 us(  0.30%)
   32768        22.540 us     40.966 us( 81.75%)         22.452 us( -0.39%)
   65536        34.192 us     73.003 us(113.51%)         33.916 us( -0.81%)

------------
Test environment notes:
1. Testing is run on 2 VMs within the same physical host
2. The NIC is ConnectX-4Lx, using SRIOV, and passing through 2 VFs to the
   2 VMs respectively.
3. To decrease jitter, VM's vCPU are binded to each physical CPU, and those
   physical CPUs are all isolated using boot parameter `isolcpus=xxx`
4. The queue number are set to 1, and interrupt from the queue is binded to
   CPU0 in the guest
====================

Signed-off-by: David S. Miller <davem@davemloft.net>
walking-machine pushed a commit that referenced this pull request Mar 10, 2022
Ido Schimmel says:

====================
HW counters for soft devices

Petr says:

Offloading switch device drivers may be able to collect statistics of the
traffic taking place in the HW datapath that pertains to a certain soft
netdevice, such as a VLAN. In this patch set, add the necessary
infrastructure to allow exposing these statistics to the offloaded
netdevice in question, and add mlxsw offload.

Across HW platforms, the counter itself very likely constitutes a limited
resource, and the act of counting may have a performance impact. Therefore
this patch set makes the HW statistics collection opt-in and togglable from
userspace on a per-netdevice basis.

Additionally, HW devices may have various limiting conditions under which
they can realize the counter. Therefore it is also possible to query
whether the requested counter is realized by any driver. In TC parlance,
which is to a degree reused in this patch set, two values are recognized:
"request" tracks whether the user enabled collecting HW statistics, and
"used" tracks whether any HW statistics are actually collected.

In the past, this author has expressed the opinion that `a typical user
doing "ip -s l sh", including various scripts, wants to see the full
picture and not worry what's going on where'. While that would be nice,
unfortunately it cannot work:

- Packets that trap from the HW datapath to the SW datapath would be
  double counted.

  For a given netdevice, some traffic can be purely a SW artifact, and some
  may flow through the HW object corresponding to the netdevice. But some
  traffic can also get trapped to the SW datapath after bumping the HW
  counter. It is not clear how to make sure double-counting does not occur
  in the SW datapath in that case, while still making sure that possibly
  divergent SW forwarding path gets bumped as appropriate.

  So simply adding HW and SW stats may work roughly, most of the time, but
  there are scenarios where the result is nonsensical.

- HW devices will have limitations as to what type of traffic they can
  count.

  In case of mlxsw, which is part of this patch set, there is no reasonable
  way to count all traffic going through a certain netdevice, such as a
  VLAN netdevice enslaved to a bridge. It is however very simple to count
  traffic flowing through an L3 object, such as a VLAN netdevice with an IP
  address.

  Similarly for physical netdevices, the L3 object at which the counter is
  installed is the subport carrying untagged traffic.

  These are not "just counters". It is important that the user understands
  what is being counted. It would be incorrect to conflate these statistics
  with another existing statistics suite.

To that end, this patch set introduces a statistics suite called "L3
stats". This label should make it easy to understand what is being counted,
and to decide whether a given device can or cannot implement this suite for
some type of netdevice. At the same time, the code is written to make
future extensions easy, should a device pop up that can implement a
different flavor of statistics suite (say L2, or an address-family-specific
suite).

For example, using a work-in-progress iproute2[1], to turn on and then list
the counters on a VLAN netdevice:

    # ip stats set dev swp1.200 l3_stats on
    # ip stats show dev swp1.200 group offload subgroup l3_stats
    56: swp1.200: group offload subgroup l3_stats on used on
	RX:  bytes packets errors dropped  missed   mcast
		0       0      0       0       0       0
	TX:  bytes packets errors dropped carrier collsns
		0       0      0       0       0       0

The patchset progresses as follows:

- Patch #1 is a cleanup.

- In patch #2, remove the assumption that all LINK_OFFLOAD_XSTATS are
  dev-backed.

  The only attribute defined under the nest is currently
  IFLA_OFFLOAD_XSTATS_CPU_HIT. L3_STATS differs from CPU_HIT in that the
  driver that supplies the statistics is not the same as the driver that
  implements the netdevice. Make the code compatible with this in patch #2.

- In patch #3, add the possibility to filter inside nests.

  The filter_mask field of RTM_GETSTATS header determines which
  top-level attributes should be included in the netlink response. This
  saves processing time by only including the bits that the user cares
  about instead of always dumping everything. This is doubly important
  for HW-backed statistics that would typically require a trip to the
  device to fetch the stats. In this patch, the UAPI is extended to
  allow filtering inside IFLA_STATS_LINK_OFFLOAD_XSTATS in particular,
  but the scheme is easily extensible to other nests as well.

- In patch #4, propagate extack where we need it.
  In patch #5, make it possible to propagate errors from drivers to the
  user.

- In patch #6, add the in-kernel APIs for keeping track of the new stats
  suite, and the notifiers that the core uses to communicate with the
  drivers.

- In patch #7, add UAPI for obtaining the new stats suite.

- In patch #8, add a new UAPI message, RTM_SETSTATS, which will carry
  the message to toggle the newly-added stats suite.
  In patch #9, add the toggle itself.

At this point the core is ready for drivers to add support for the new
stats suite.

- In patches #10, #11 and #12, apply small tweaks to mlxsw code.

- In patch #13, add support for L3 stats, which are realized as RIF
  counters.

- Finally in patch #14, a selftest is added to the net/forwarding
  directory. Technically this is a HW-specific test, in that without a HW
  implementing the counters, it just will not pass. But devices that
  support L3 statistics at all are likely to be able to reuse this
  selftest, so it seems appropriate to put it in the general forwarding
  directory.

We also have a netdevsim implementation, and a corresponding selftest that
verifies specifically some of the core code. We intend to contribute these
later. Interested parties can take a look at the raw code at [2].

[1] https://github.com/pmachata/iproute2/commits/soft_counters
[2] https://github.com/pmachata/linux_mlxsw/commits/petrm_soft_counters_2

v2:
- Patch #3:
    - Do not declare strict_start_type at the new policies, since they are
      used with nla_parse_nested() (sans _deprecated).
    - Use NLA_POLICY_NESTED to declare what the nest contents should be
    - Use NLA_POLICY_MASK instead of BITFIELD32 for the filtering
      attribute.
- Patch #6:
    - s/monotonous/monotonic/ in commit message
    - Use a newly-added struct rtnl_hw_stats64 for stats transfer
- Patch #7:
    - Use a newly-added struct rtnl_hw_stats64 for stats transfer
- Patch #8:
    - Do not declare strict_start_type at the new policies, since they are
      used with nla_parse_nested() (sans _deprecated).
- Patch #13:
    - Use a newly-added struct rtnl_hw_stats64 for stats transfer
====================

Signed-off-by: David S. Miller <davem@davemloft.net>
alobakin pushed a commit that referenced this pull request Feb 19, 2025
Suman Ghosh says:

====================
Add af_xdp support for cn10k

This patchset includes changes to support AF_XDP for cn10k chipsets. Both
non-zero copy and zero copy will be supported after these changes. Also,
the RSS will be reconfigured once a particular receive queue is
added/removed to/from AF_XDP support.

Patch #1: octeontx2-pf: use xdp_return_frame() to free xdp buffers

Patch #2: octeontx2-pf: Add AF_XDP non-zero copy support

Patch #3: octeontx2-pf: AF_XDP zero copy receive support

Patch #4: octeontx2-pf: Reconfigure RSS table after enabling AF_XDP
zerocopy on rx queue

Patch #5: octeontx2-pf: Prepare for AF_XDP transmit

Patch #6: octeontx2-pf: AF_XDP zero copy transmit support
====================

Link: https://patch.msgid.link/20250213053141.2833254-1-sumang@marvell.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
alobakin pushed a commit that referenced this pull request Feb 20, 2025
Ido Schimmel says:

====================
net: fib_rules: Add port mask support

In some deployments users would like to encode path information into
certain bits of the IPv6 flow label, the UDP source port and the DSCP
field and use this information to route packets accordingly.

Redirecting traffic to a routing table based on specific bits in the UDP
source port is not currently possible. Only exact match and range are
currently supported by FIB rules.

This patchset extends FIB rules to match on layer 4 ports with an
optional mask. The mask is not supported when matching on a range. A
future patchset will add support for matching on the DSCP field with an
optional mask.

Patches #1-#6 gradually extend FIB rules to match on layer 4 ports with
an optional mask.

Patches #7-#8 add test cases for FIB rule port matching.

iproute2 support can be found here [1].

[1] https://github.com/idosch/iproute2/tree/submit/fib_rule_mask_v1
====================

Link: https://patch.msgid.link/20250217134109.311176-1-idosch@nvidia.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
alobakin pushed a commit that referenced this pull request Feb 21, 2025
We have several places across the kernel where we want to access another
task's syscall arguments, such as ptrace(2), seccomp(2), etc., by making
a call to syscall_get_arguments().

This works for register arguments right away by accessing the task's
`regs' member of `struct pt_regs', however for stack arguments seen with
32-bit/o32 kernels things are more complicated.  Technically they ought
to be obtained from the user stack with calls to an access_remote_vm(),
but we have an easier way available already.

So as to be able to access syscall stack arguments as regular function
arguments following the MIPS calling convention we copy them over from
the user stack to the kernel stack in arch/mips/kernel/scall32-o32.S, in
handle_sys(), to the current stack frame's outgoing argument space at
the top of the stack, which is where the handler called expects to see
its incoming arguments.  This area is also pointed at by the `pt_regs'
pointer obtained by task_pt_regs().

Make the o32 stack argument space a proper member of `struct pt_regs'
then, by renaming the existing member from `pad0' to `args' and using
generated offsets to access the space.  No functional change though.

With the change in place the o32 kernel stack frame layout at the entry
to a syscall handler invoked by handle_sys() is therefore as follows:

$sp + 68 -> |         ...         | <- pt_regs.regs[9]
            +---------------------+
$sp + 64 -> |         $t0         | <- pt_regs.regs[8]
            +---------------------+
$sp + 60 -> |   $a3/argument #4   | <- pt_regs.regs[7]
            +---------------------+
$sp + 56 -> |   $a2/argument #3   | <- pt_regs.regs[6]
            +---------------------+
$sp + 52 -> |   $a1/argument #2   | <- pt_regs.regs[5]
            +---------------------+
$sp + 48 -> |   $a0/argument #1   | <- pt_regs.regs[4]
            +---------------------+
$sp + 44 -> |         $v1         | <- pt_regs.regs[3]
            +---------------------+
$sp + 40 -> |         $v0         | <- pt_regs.regs[2]
            +---------------------+
$sp + 36 -> |         $at         | <- pt_regs.regs[1]
            +---------------------+
$sp + 32 -> |        $zero        | <- pt_regs.regs[0]
            +---------------------+
$sp + 28 -> |  stack argument #8  | <- pt_regs.args[7]
            +---------------------+
$sp + 24 -> |  stack argument #7  | <- pt_regs.args[6]
            +---------------------+
$sp + 20 -> |  stack argument #6  | <- pt_regs.args[5]
            +---------------------+
$sp + 16 -> |  stack argument #5  | <- pt_regs.args[4]
            +---------------------+
$sp + 12 -> | psABI space for $a3 | <- pt_regs.args[3]
            +---------------------+
$sp +  8 -> | psABI space for $a2 | <- pt_regs.args[2]
            +---------------------+
$sp +  4 -> | psABI space for $a1 | <- pt_regs.args[1]
            +---------------------+
$sp +  0 -> | psABI space for $a0 | <- pt_regs.args[0]
            +---------------------+

holding user data received and with the first 4 frame slots reserved by
the psABI for the compiler to spill the incoming arguments from $a0-$a3
registers (which it sometimes does according to its needs) and the next
4 frame slots designated by the psABI for any stack function arguments
that follow.  This data is also available for other tasks to peek/poke
at as reqired and where permitted.

Signed-off-by: Maciej W. Rozycki <macro@orcam.me.uk>
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
alobakin pushed a commit that referenced this pull request Feb 21, 2025
This makes ptrace/get_syscall_info selftest pass on mips o32 and
mips64 o32 by fixing the following two test assertions:

1. get_syscall_info test assertion on mips o32:
  # get_syscall_info.c:218:get_syscall_info:Expected exp_args[5] (3134521044) == info.entry.args[4] (4911432)
  # get_syscall_info.c:219:get_syscall_info:wait #1: entry stop mismatch

2. get_syscall_info test assertion on mips64 o32:
  # get_syscall_info.c:209:get_syscall_info:Expected exp_args[2] (3134324433) == info.entry.args[1] (18446744072548908753)
  # get_syscall_info.c:210:get_syscall_info:wait #1: entry stop mismatch

The first assertion happens due to mips_get_syscall_arg() trying to access
another task's context but failing to do it properly because get_user() it
calls just peeks at the current task's context.  It usually does not crash
because the default user stack always gets assigned the same VMA, but it
is pure luck which mips_get_syscall_arg() wouldn't have if e.g. the stack
was switched (via setcontext(3) or however) or a non-default process's
thread peeked at, and in any case irrelevant data is obtained just as
observed with the test case.

mips_get_syscall_arg() ought to be using access_remote_vm() instead to
retrieve the other task's stack contents, but given that the data has been
already obtained and saved in `struct pt_regs' it would be an overkill.

The first assertion is fixed for mips o32 by using struct pt_regs.args
instead of get_user() to obtain syscall arguments.  This approach works
due to this piece in arch/mips/kernel/scall32-o32.S:

        /*
         * Ok, copy the args from the luser stack to the kernel stack.
         */

        .set    push
        .set    noreorder
        .set    nomacro

    load_a4: user_lw(t5, 16(t0))		# argument #5 from usp
    load_a5: user_lw(t6, 20(t0))		# argument #6 from usp
    load_a6: user_lw(t7, 24(t0))		# argument #7 from usp
    load_a7: user_lw(t8, 28(t0))		# argument #8 from usp
    loads_done:

        sw	t5, PT_ARG4(sp)		# argument #5 to ksp
        sw	t6, PT_ARG5(sp)		# argument #6 to ksp
        sw	t7, PT_ARG6(sp)		# argument #7 to ksp
        sw	t8, PT_ARG7(sp)		# argument #8 to ksp
        .set	pop

        .section __ex_table,"a"
        PTR_WD	load_a4, bad_stack_a4
        PTR_WD	load_a5, bad_stack_a5
        PTR_WD	load_a6, bad_stack_a6
        PTR_WD	load_a7, bad_stack_a7
        .previous

arch/mips/kernel/scall64-o32.S has analogous code for mips64 o32 that
allows fixing the issue by obtaining syscall arguments from struct
pt_regs.regs[4..11] instead of the erroneous use of get_user().

The second assertion is fixed by truncating 64-bit values to 32-bit
syscall arguments.

Fixes: c0ff3c5 ("MIPS: Enable HAVE_ARCH_TRACEHOOK.")
Signed-off-by: Dmitry V. Levin <ldv@strace.io>
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
alobakin pushed a commit that referenced this pull request Feb 25, 2025
Ido Schimmel says:

====================
net: fib_rules: Add DSCP mask support

In some deployments users would like to encode path information into
certain bits of the IPv6 flow label, the UDP source port and the DSCP
field and use this information to route packets accordingly.

Redirecting traffic to a routing table based on specific bits in the
DSCP field is not currently possible. Only exact match is currently
supported by FIB rules.

This patchset extends FIB rules to match on the DSCP field with an
optional mask.

Patches #1-#5 gradually extend FIB rules to match on the DSCP field with
an optional mask.

Patch #6 adds test cases for the new functionality.

iproute2 support can be found here [1].

[1] https://github.com/idosch/iproute2/tree/submit/fib_rule_mask_v1
====================

Link: https://patch.msgid.link/20250220080525.831924-1-idosch@nvidia.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
alobakin pushed a commit that referenced this pull request Mar 17, 2025
Chia-Yu Chang says:

====================
AccECN protocol preparation patch series

Please find the v7

v7 (03-Mar-2025)
- Move 2 new patches added in v6 to the next AccECN patch series

v6 (27-Dec-2024)
- Avoid removing removing the potential CA_ACK_WIN_UPDATE in ack_ev_flags of patch #1 (Eric Dumazet <edumazet@google.com>)
- Add reviewed-by tag in patches #2, #3, #4, #5, #6, #7, #8, #12, #14
- Foloiwng 2 new pathces are added after patch #9 (Patch that adds SKB_GSO_TCP_ACCECN)
  * New patch #10 to replace exisiting SKB_GSO_TCP_ECN with SKB_GSO_TCP_ACCECN in the driver to avoid CWR flag corruption
  * New patch #11 adds AccECN for virtio by adding new negotiation flag (VIRTIO_NET_F_HOST/GUEST_ACCECN) in feature handshake and translating Accurate ECN GSO flag between virtio_net_hdr (VIRTIO_NET_HDR_GSO_ACCECN) and skb header (SKB_GSO_TCP_ACCECN)
- Add detailed changelog and comments in #13 (Eric Dumazet <edumazet@google.com>)
- Move patch #14 to the next AccECN patch series (Eric Dumazet <edumazet@google.com>)

v5 (5-Nov-2024)
- Add helper function "tcp_flags_ntohs" to preserve last 2 bytes of TCP flags of patch #4 (Paolo Abeni <pabeni@redhat.com>)
- Fix reverse X-max tree order of patches #4, #11 (Paolo Abeni <pabeni@redhat.com>)
- Rename variable "delta" as "timestamp_delta" of patch #2 fo clariety
- Remove patch #14 in this series (Paolo Abeni <pabeni@redhat.com>, Joel Granados <joel.granados@kernel.org>)

v4 (21-Oct-2024)
- Fix line length warning of patches #2, #4, #8, #10, #11, #14
- Fix spaces preferred around '|' (ctx:VxV) warning of patch #7
- Add missing CC'ed of patches #4, #12, #14

v3 (19-Oct-2024)
- Fix build error in v2

v2 (18-Oct-2024)
- Fix warning caused by NETIF_F_GSO_ACCECN_BIT in patch #9 (Jakub Kicinski <kuba@kernel.org>)

The full patch series can be found in
https://github.com/L4STeam/linux-net-next/commits/upstream_l4steam/

The Accurate ECN draft can be found in
https://datatracker.ietf.org/doc/html/draft-ietf-tcpm-accurate-ecn-28
====================

Signed-off-by: David S. Miller <davem@davemloft.net>
alobakin pushed a commit that referenced this pull request Mar 28, 2025
We have recently seen report of lockdep circular lock dependency warnings
on platforms like Skylake and Kabylake:

 ======================================================
 WARNING: possible circular locking dependency detected
 6.14.0-rc6-CI_DRM_16276-gca2c04fe76e8+ #1 Not tainted
 ------------------------------------------------------
 swapper/0/1 is trying to acquire lock:
 ffffffff8360ee48 (iommu_probe_device_lock){+.+.}-{3:3},
   at: iommu_probe_device+0x1d/0x70

 but task is already holding lock:
 ffff888102c7efa8 (&device->physical_node_lock){+.+.}-{3:3},
   at: intel_iommu_init+0xe75/0x11f0

 which lock already depends on the new lock.

 the existing dependency chain (in reverse order) is:

 -> #6 (&device->physical_node_lock){+.+.}-{3:3}:
        __mutex_lock+0xb4/0xe40
        mutex_lock_nested+0x1b/0x30
        intel_iommu_init+0xe75/0x11f0
        pci_iommu_init+0x13/0x70
        do_one_initcall+0x62/0x3f0
        kernel_init_freeable+0x3da/0x6a0
        kernel_init+0x1b/0x200
        ret_from_fork+0x44/0x70
        ret_from_fork_asm+0x1a/0x30

 -> #5 (dmar_global_lock){++++}-{3:3}:
        down_read+0x43/0x1d0
        enable_drhd_fault_handling+0x21/0x110
        cpuhp_invoke_callback+0x4c6/0x870
        cpuhp_issue_call+0xbf/0x1f0
        __cpuhp_setup_state_cpuslocked+0x111/0x320
        __cpuhp_setup_state+0xb0/0x220
        irq_remap_enable_fault_handling+0x3f/0xa0
        apic_intr_mode_init+0x5c/0x110
        x86_late_time_init+0x24/0x40
        start_kernel+0x895/0xbd0
        x86_64_start_reservations+0x18/0x30
        x86_64_start_kernel+0xbf/0x110
        common_startup_64+0x13e/0x141

 -> #4 (cpuhp_state_mutex){+.+.}-{3:3}:
        __mutex_lock+0xb4/0xe40
        mutex_lock_nested+0x1b/0x30
        __cpuhp_setup_state_cpuslocked+0x67/0x320
        __cpuhp_setup_state+0xb0/0x220
        page_alloc_init_cpuhp+0x2d/0x60
        mm_core_init+0x18/0x2c0
        start_kernel+0x576/0xbd0
        x86_64_start_reservations+0x18/0x30
        x86_64_start_kernel+0xbf/0x110
        common_startup_64+0x13e/0x141

 -> #3 (cpu_hotplug_lock){++++}-{0:0}:
        __cpuhp_state_add_instance+0x4f/0x220
        iova_domain_init_rcaches+0x214/0x280
        iommu_setup_dma_ops+0x1a4/0x710
        iommu_device_register+0x17d/0x260
        intel_iommu_init+0xda4/0x11f0
        pci_iommu_init+0x13/0x70
        do_one_initcall+0x62/0x3f0
        kernel_init_freeable+0x3da/0x6a0
        kernel_init+0x1b/0x200
        ret_from_fork+0x44/0x70
        ret_from_fork_asm+0x1a/0x30

 -> #2 (&domain->iova_cookie->mutex){+.+.}-{3:3}:
        __mutex_lock+0xb4/0xe40
        mutex_lock_nested+0x1b/0x30
        iommu_setup_dma_ops+0x16b/0x710
        iommu_device_register+0x17d/0x260
        intel_iommu_init+0xda4/0x11f0
        pci_iommu_init+0x13/0x70
        do_one_initcall+0x62/0x3f0
        kernel_init_freeable+0x3da/0x6a0
        kernel_init+0x1b/0x200
        ret_from_fork+0x44/0x70
        ret_from_fork_asm+0x1a/0x30

 -> #1 (&group->mutex){+.+.}-{3:3}:
        __mutex_lock+0xb4/0xe40
        mutex_lock_nested+0x1b/0x30
        __iommu_probe_device+0x24c/0x4e0
        probe_iommu_group+0x2b/0x50
        bus_for_each_dev+0x7d/0xe0
        iommu_device_register+0xe1/0x260
        intel_iommu_init+0xda4/0x11f0
        pci_iommu_init+0x13/0x70
        do_one_initcall+0x62/0x3f0
        kernel_init_freeable+0x3da/0x6a0
        kernel_init+0x1b/0x200
        ret_from_fork+0x44/0x70
        ret_from_fork_asm+0x1a/0x30

 -> #0 (iommu_probe_device_lock){+.+.}-{3:3}:
        __lock_acquire+0x1637/0x2810
        lock_acquire+0xc9/0x300
        __mutex_lock+0xb4/0xe40
        mutex_lock_nested+0x1b/0x30
        iommu_probe_device+0x1d/0x70
        intel_iommu_init+0xe90/0x11f0
        pci_iommu_init+0x13/0x70
        do_one_initcall+0x62/0x3f0
        kernel_init_freeable+0x3da/0x6a0
        kernel_init+0x1b/0x200
        ret_from_fork+0x44/0x70
        ret_from_fork_asm+0x1a/0x30

 other info that might help us debug this:

 Chain exists of:
   iommu_probe_device_lock --> dmar_global_lock -->
     &device->physical_node_lock

  Possible unsafe locking scenario:

        CPU0                    CPU1
        ----                    ----
   lock(&device->physical_node_lock);
                                lock(dmar_global_lock);
                                lock(&device->physical_node_lock);
   lock(iommu_probe_device_lock);

  *** DEADLOCK ***

This driver uses a global lock to protect the list of enumerated DMA
remapping units. It is necessary due to the driver's support for dynamic
addition and removal of remapping units at runtime.

Two distinct code paths require iteration over this remapping unit list:

- Device registration and probing: the driver iterates the list to
  register each remapping unit with the upper layer IOMMU framework
  and subsequently probe the devices managed by that unit.
- Global configuration: Upper layer components may also iterate the list
  to apply configuration changes.

The lock acquisition order between these two code paths was reversed. This
caused lockdep warnings, indicating a risk of deadlock. Fix this warning
by releasing the global lock before invoking upper layer interfaces for
device registration.

Fixes: b150654 ("iommu/vt-d: Fix suspicious RCU usage")
Closes: https://lore.kernel.org/linux-iommu/SJ1PR11MB612953431F94F18C954C4A9CB9D32@SJ1PR11MB6129.namprd11.prod.outlook.com/
Tested-by: Chaitanya Kumar Borah <chaitanya.kumar.borah@intel.com>
Cc: stable@vger.kernel.org
Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
Link: https://lore.kernel.org/r/20250317035714.1041549-1-baolu.lu@linux.intel.com
Signed-off-by: Joerg Roedel <jroedel@suse.de>
alobakin pushed a commit that referenced this pull request Mar 28, 2025
…-bridge-ports'

Petr Machata says:

====================
mlxsw: Add VXLAN to the same hardware domain as physical bridge ports

Amit Cohen writes:

Packets which are trapped to CPU for forwarding in software data path
are handled according to driver marking of skb->offload_{,l3}_fwd_mark.
Packets which are marked as L2-forwarded in hardware, will not be flooded
by the bridge to bridge ports which are in the same hardware domain as the
ingress port.

Currently, mlxsw does not add VXLAN bridge ports to the same hardware
domain as physical bridge ports despite the fact that the device is able
to forward packets to and from VXLAN tunnels in hardware. In some
scenarios this can result in remote VTEPs receiving duplicate packets.

To solve such packets duplication, add VXLAN bridge ports to the same
hardware domain as other bridge ports.

One complication is ARP suppression which requires the local VTEP to avoid
flooding ARP packets to remote VTEPs if the local VTEP is able to reply on
behalf of remote hosts. This is currently implemented by having the device
flood ARP packets in hardware and trapping them during VXLAN encapsulation,
but marking them with skb->offload_fwd_mark=1 so that the bridge will not
re-flood them to physical bridge ports.

The above scheme will break when VXLAN bridge ports are added to the same
hardware domain as physical bridge ports as ARP packets that cannot be
suppressed by the bridge will not be able to egress the VXLAN bridge ports
due to hardware domain filtering. This is solved by trapping ARP packets
when they enter the device and not marking them as being forwarded in
hardware.

Patch set overview:
Patch #1 sets hardware to trap ARP packets at layer 2
Patches #2-#4 are preparations for setting hardwarwe domain of VXLAN
Patch #5 sets hardware domain of VXLAN
Patch #6 extends VXLAN flood test to verify that this set solves the
packets duplication
====================

Link: https://patch.msgid.link/cover.1742224300.git.petrm@nvidia.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
alobakin pushed a commit that referenced this pull request Mar 28, 2025
…uctions

Add several ./test_progs tests:

  - arena_atomics/load_acquire
  - arena_atomics/store_release
  - verifier_load_acquire/*
  - verifier_store_release/*
  - verifier_precision/bpf_load_acquire
  - verifier_precision/bpf_store_release

The last two tests are added to check if backtrack_insn() handles the
new instructions correctly.

Additionally, the last test also makes sure that the verifier
"remembers" the value (in src_reg) we store-release into e.g. a stack
slot.  For example, if we take a look at the test program:

    #0:  r1 = 8;
      /* store_release((u64 *)(r10 - 8), r1); */
    #1:  .8byte %[store_release];
    #2:  r1 = *(u64 *)(r10 - 8);
    #3:  r2 = r10;
    #4:  r2 += r1;
    #5:  r0 = 0;
    #6:  exit;

At #1, if the verifier doesn't remember that we wrote 8 to the stack,
then later at #4 we would be adding an unbounded scalar value to the
stack pointer, which would cause the program to be rejected:

  VERIFIER LOG:
  =============
...
  math between fp pointer and register with unbounded min value is not allowed

For easier CI integration, instead of using built-ins like
__atomic_{load,store}_n() which depend on the new
__BPF_FEATURE_LOAD_ACQ_STORE_REL pre-defined macro, manually craft
load-acquire/store-release instructions using __imm_insn(), as suggested
by Eduard.

All new tests depend on:

  (1) Clang major version >= 18, and
  (2) ENABLE_ATOMICS_TESTS is defined (currently implies -mcpu=v3 or
      v4), and
  (3) JIT supports load-acquire/store-release (currently arm64 and
      x86-64)

In .../progs/arena_atomics.c:

  /* 8-byte-aligned */
  __u8 __arena_global load_acquire8_value = 0x12;
  /* 1-byte hole */
  __u16 __arena_global load_acquire16_value = 0x1234;

That 1-byte hole in the .addr_space.1 ELF section caused clang-17 to
crash:

  fatal error: error in backend: unable to write nop sequence of 1 bytes

To work around such llvm-17 CI job failures, conditionally define
__arena_global variables as 64-bit if __clang_major__ < 18, to make sure
.addr_space.1 has no holes.  Ideally we should avoid compiling this file
using clang-17 at all (arena tests depend on
__BPF_FEATURE_ADDR_SPACE_CAST, and are skipped for llvm-17 anyway), but
that is a separate topic.

Acked-by: Eduard Zingerman <eddyz87@gmail.com>
Signed-off-by: Peilin Ye <yepeilin@google.com>
Link: https://lore.kernel.org/r/1b46c6feaf0f1b6984d9ec80e500cc7383e9da1a.1741049567.git.yepeilin@google.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
alobakin pushed a commit that referenced this pull request Mar 28, 2025
In recent kernels, there are lockdep splats around the
struct request_queue::io_lockdep_map, similar to [1], but they
typically don't show up until reclaim with writeback happens.

Having multiple kernel versions released with a known risc of kernel
deadlock during reclaim writeback should IMHO be addressed and
backported to -stable with the highest priority.

In order to have these lockdep splats show up earlier,
preferrably during system initialization, prime the
struct request_queue::io_lockdep_map as GFP_KERNEL reclaim-
tainted. This will instead lead to lockdep splats looking similar
to [2], but without the need for reclaim + writeback
happening.

[1]:
[  189.762244] ======================================================
[  189.762432] WARNING: possible circular locking dependency detected
[  189.762441] 6.14.0-rc6-xe+ #6 Tainted: G     U
[  189.762450] ------------------------------------------------------
[  189.762459] kswapd0/119 is trying to acquire lock:
[  189.762467] ffff888110ceb710 (&q->q_usage_counter(io)#26){++++}-{0:0}, at: __submit_bio+0x76/0x230
[  189.762485]
               but task is already holding lock:
[  189.762494] ffffffff834c97c0 (fs_reclaim){+.+.}-{0:0}, at: balance_pgdat+0xbe/0xb00
[  189.762507]
               which lock already depends on the new lock.

[  189.762519]
               the existing dependency chain (in reverse order) is:
[  189.762529]
               -> #2 (fs_reclaim){+.+.}-{0:0}:
[  189.762540]        fs_reclaim_acquire+0xc5/0x100
[  189.762548]        kmem_cache_alloc_lru_noprof+0x4a/0x480
[  189.762558]        alloc_inode+0xaa/0xe0
[  189.762566]        iget_locked+0x157/0x330
[  189.762573]        kernfs_get_inode+0x1b/0x110
[  189.762582]        kernfs_get_tree+0x1b0/0x2e0
[  189.762590]        sysfs_get_tree+0x1f/0x60
[  189.762597]        vfs_get_tree+0x2a/0xf0
[  189.762605]        path_mount+0x4cd/0xc00
[  189.762613]        __x64_sys_mount+0x119/0x150
[  189.762621]        x64_sys_call+0x14f2/0x2310
[  189.762630]        do_syscall_64+0x91/0x180
[  189.762637]        entry_SYSCALL_64_after_hwframe+0x76/0x7e
[  189.762647]
               -> #1 (&root->kernfs_rwsem){++++}-{3:3}:
[  189.762659]        down_write+0x3e/0xf0
[  189.762667]        kernfs_remove+0x32/0x60
[  189.762676]        sysfs_remove_dir+0x4f/0x60
[  189.762685]        __kobject_del+0x33/0xa0
[  189.762709]        kobject_del+0x13/0x30
[  189.762716]        elv_unregister_queue+0x52/0x80
[  189.762725]        elevator_switch+0x68/0x360
[  189.762733]        elv_iosched_store+0x14b/0x1b0
[  189.762756]        queue_attr_store+0x181/0x1e0
[  189.762765]        sysfs_kf_write+0x49/0x80
[  189.762773]        kernfs_fop_write_iter+0x17d/0x250
[  189.762781]        vfs_write+0x281/0x540
[  189.762790]        ksys_write+0x72/0xf0
[  189.762798]        __x64_sys_write+0x19/0x30
[  189.762807]        x64_sys_call+0x2a3/0x2310
[  189.762815]        do_syscall_64+0x91/0x180
[  189.762823]        entry_SYSCALL_64_after_hwframe+0x76/0x7e
[  189.762833]
               -> #0 (&q->q_usage_counter(io)#26){++++}-{0:0}:
[  189.762845]        __lock_acquire+0x1525/0x2760
[  189.762854]        lock_acquire+0xca/0x310
[  189.762861]        blk_mq_submit_bio+0x8a2/0xba0
[  189.762870]        __submit_bio+0x76/0x230
[  189.762878]        submit_bio_noacct_nocheck+0x323/0x430
[  189.762888]        submit_bio_noacct+0x2cc/0x620
[  189.762896]        submit_bio+0x38/0x110
[  189.762904]        __swap_writepage+0xf5/0x380
[  189.762912]        swap_writepage+0x3c7/0x600
[  189.762920]        shmem_writepage+0x3da/0x4f0
[  189.762929]        pageout+0x13f/0x310
[  189.762937]        shrink_folio_list+0x61c/0xf60
[  189.763261]        evict_folios+0x378/0xcd0
[  189.763584]        try_to_shrink_lruvec+0x1b0/0x360
[  189.763946]        shrink_one+0x10e/0x200
[  189.764266]        shrink_node+0xc02/0x1490
[  189.764586]        balance_pgdat+0x563/0xb00
[  189.764934]        kswapd+0x1e8/0x430
[  189.765249]        kthread+0x10b/0x260
[  189.765559]        ret_from_fork+0x44/0x70
[  189.765889]        ret_from_fork_asm+0x1a/0x30
[  189.766198]
               other info that might help us debug this:

[  189.767089] Chain exists of:
                 &q->q_usage_counter(io)#26 --> &root->kernfs_rwsem --> fs_reclaim

[  189.767971]  Possible unsafe locking scenario:

[  189.768555]        CPU0                    CPU1
[  189.768849]        ----                    ----
[  189.769136]   lock(fs_reclaim);
[  189.769421]                                lock(&root->kernfs_rwsem);
[  189.769714]                                lock(fs_reclaim);
[  189.770016]   rlock(&q->q_usage_counter(io)#26);
[  189.770305]
                *** DEADLOCK ***

[  189.771167] 1 lock held by kswapd0/119:
[  189.771453]  #0: ffffffff834c97c0 (fs_reclaim){+.+.}-{0:0}, at: balance_pgdat+0xbe/0xb00
[  189.771770]
               stack backtrace:
[  189.772351] CPU: 4 UID: 0 PID: 119 Comm: kswapd0 Tainted: G     U             6.14.0-rc6-xe+ #6
[  189.772353] Tainted: [U]=USER
[  189.772354] Hardware name: ASUS System Product Name/PRIME B560M-A AC, BIOS 2001 02/01/2023
[  189.772354] Call Trace:
[  189.772355]  <TASK>
[  189.772356]  dump_stack_lvl+0x6e/0xa0
[  189.772359]  dump_stack+0x10/0x18
[  189.772360]  print_circular_bug.cold+0x17a/0x1b7
[  189.772363]  check_noncircular+0x13a/0x150
[  189.772365]  ? __pfx_stack_trace_consume_entry+0x10/0x10
[  189.772368]  __lock_acquire+0x1525/0x2760
[  189.772368]  ? ret_from_fork_asm+0x1a/0x30
[  189.772371]  lock_acquire+0xca/0x310
[  189.772372]  ? __submit_bio+0x76/0x230
[  189.772375]  ? lock_release+0xd5/0x2c0
[  189.772376]  blk_mq_submit_bio+0x8a2/0xba0
[  189.772378]  ? __submit_bio+0x76/0x230
[  189.772380]  __submit_bio+0x76/0x230
[  189.772382]  ? trace_hardirqs_on+0x1e/0xe0
[  189.772384]  submit_bio_noacct_nocheck+0x323/0x430
[  189.772386]  ? submit_bio_noacct_nocheck+0x323/0x430
[  189.772387]  ? __might_sleep+0x58/0xa0
[  189.772390]  submit_bio_noacct+0x2cc/0x620
[  189.772391]  ? count_memcg_events+0x68/0x90
[  189.772393]  submit_bio+0x38/0x110
[  189.772395]  __swap_writepage+0xf5/0x380
[  189.772396]  swap_writepage+0x3c7/0x600
[  189.772397]  shmem_writepage+0x3da/0x4f0
[  189.772401]  pageout+0x13f/0x310
[  189.772406]  shrink_folio_list+0x61c/0xf60
[  189.772409]  ? isolate_folios+0xe80/0x16b0
[  189.772410]  ? mark_held_locks+0x46/0x90
[  189.772412]  evict_folios+0x378/0xcd0
[  189.772414]  ? evict_folios+0x34a/0xcd0
[  189.772415]  ? lock_is_held_type+0xa3/0x130
[  189.772417]  try_to_shrink_lruvec+0x1b0/0x360
[  189.772420]  shrink_one+0x10e/0x200
[  189.772421]  shrink_node+0xc02/0x1490
[  189.772423]  ? shrink_node+0xa08/0x1490
[  189.772424]  ? shrink_node+0xbd8/0x1490
[  189.772425]  ? mem_cgroup_iter+0x366/0x480
[  189.772427]  balance_pgdat+0x563/0xb00
[  189.772428]  ? balance_pgdat+0x563/0xb00
[  189.772430]  ? trace_hardirqs_on+0x1e/0xe0
[  189.772431]  ? finish_task_switch.isra.0+0xcb/0x330
[  189.772433]  ? __switch_to_asm+0x33/0x70
[  189.772437]  kswapd+0x1e8/0x430
[  189.772438]  ? __pfx_autoremove_wake_function+0x10/0x10
[  189.772440]  ? __pfx_kswapd+0x10/0x10
[  189.772441]  kthread+0x10b/0x260
[  189.772443]  ? __pfx_kthread+0x10/0x10
[  189.772444]  ret_from_fork+0x44/0x70
[  189.772446]  ? __pfx_kthread+0x10/0x10
[  189.772447]  ret_from_fork_asm+0x1a/0x30
[  189.772450]  </TASK>

[2]:
[    8.760253] ======================================================
[    8.760254] WARNING: possible circular locking dependency detected
[    8.760255] 6.14.0-rc6-xe+ #7 Tainted: G     U
[    8.760256] ------------------------------------------------------
[    8.760257] (udev-worker)/674 is trying to acquire lock:
[    8.760259] ffff888100e39148 (&root->kernfs_rwsem){++++}-{3:3}, at: kernfs_remove+0x32/0x60
[    8.760265]
               but task is already holding lock:
[    8.760266] ffff888110dc7680 (&q->q_usage_counter(io)#27){++++}-{0:0}, at: blk_mq_freeze_queue_nomemsave+0x12/0x30
[    8.760272]
               which lock already depends on the new lock.

[    8.760272]
               the existing dependency chain (in reverse order) is:
[    8.760273]
               -> #2 (&q->q_usage_counter(io)#27){++++}-{0:0}:
[    8.760276]        blk_alloc_queue+0x30a/0x350
[    8.760279]        blk_mq_alloc_queue+0x6b/0xe0
[    8.760281]        scsi_alloc_sdev+0x276/0x3c0
[    8.760284]        scsi_probe_and_add_lun+0x22a/0x440
[    8.760286]        __scsi_scan_target+0x109/0x230
[    8.760288]        scsi_scan_channel+0x65/0xc0
[    8.760290]        scsi_scan_host_selected+0xff/0x140
[    8.760292]        do_scsi_scan_host+0xa7/0xc0
[    8.760293]        do_scan_async+0x1c/0x160
[    8.760295]        async_run_entry_fn+0x32/0x150
[    8.760299]        process_one_work+0x224/0x5f0
[    8.760302]        worker_thread+0x1d4/0x3e0
[    8.760304]        kthread+0x10b/0x260
[    8.760306]        ret_from_fork+0x44/0x70
[    8.760309]        ret_from_fork_asm+0x1a/0x30
[    8.760312]
               -> #1 (fs_reclaim){+.+.}-{0:0}:
[    8.760315]        fs_reclaim_acquire+0xc5/0x100
[    8.760317]        kmem_cache_alloc_lru_noprof+0x4a/0x480
[    8.760319]        alloc_inode+0xaa/0xe0
[    8.760322]        iget_locked+0x157/0x330
[    8.760323]        kernfs_get_inode+0x1b/0x110
[    8.760325]        kernfs_get_tree+0x1b0/0x2e0
[    8.760327]        sysfs_get_tree+0x1f/0x60
[    8.760329]        vfs_get_tree+0x2a/0xf0
[    8.760332]        path_mount+0x4cd/0xc00
[    8.760334]        __x64_sys_mount+0x119/0x150
[    8.760336]        x64_sys_call+0x14f2/0x2310
[    8.760338]        do_syscall_64+0x91/0x180
[    8.760340]        entry_SYSCALL_64_after_hwframe+0x76/0x7e
[    8.760342]
               -> #0 (&root->kernfs_rwsem){++++}-{3:3}:
[    8.760345]        __lock_acquire+0x1525/0x2760
[    8.760347]        lock_acquire+0xca/0x310
[    8.760348]        down_write+0x3e/0xf0
[    8.760350]        kernfs_remove+0x32/0x60
[    8.760351]        sysfs_remove_dir+0x4f/0x60
[    8.760353]        __kobject_del+0x33/0xa0
[    8.760355]        kobject_del+0x13/0x30
[    8.760356]        elv_unregister_queue+0x52/0x80
[    8.760358]        elevator_switch+0x68/0x360
[    8.760360]        elv_iosched_store+0x14b/0x1b0
[    8.760362]        queue_attr_store+0x181/0x1e0
[    8.760364]        sysfs_kf_write+0x49/0x80
[    8.760366]        kernfs_fop_write_iter+0x17d/0x250
[    8.760367]        vfs_write+0x281/0x540
[    8.760370]        ksys_write+0x72/0xf0
[    8.760372]        __x64_sys_write+0x19/0x30
[    8.760374]        x64_sys_call+0x2a3/0x2310
[    8.760376]        do_syscall_64+0x91/0x180
[    8.760377]        entry_SYSCALL_64_after_hwframe+0x76/0x7e
[    8.760380]
               other info that might help us debug this:

[    8.760380] Chain exists of:
                 &root->kernfs_rwsem --> fs_reclaim --> &q->q_usage_counter(io)#27

[    8.760384]  Possible unsafe locking scenario:

[    8.760384]        CPU0                    CPU1
[    8.760385]        ----                    ----
[    8.760385]   lock(&q->q_usage_counter(io)#27);
[    8.760387]                                lock(fs_reclaim);
[    8.760388]                                lock(&q->q_usage_counter(io)#27);
[    8.760390]   lock(&root->kernfs_rwsem);
[    8.760391]
                *** DEADLOCK ***

[    8.760391] 6 locks held by (udev-worker)/674:
[    8.760392]  #0: ffff8881209ac420 (sb_writers#4){.+.+}-{0:0}, at: ksys_write+0x72/0xf0
[    8.760398]  #1: ffff88810c80f488 (&of->mutex#2){+.+.}-{3:3}, at: kernfs_fop_write_iter+0x136/0x250
[    8.760402]  #2: ffff888125d1d330 (kn->active#101){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x13f/0x250
[    8.760406]  #3: ffff888110dc7bb0 (&q->sysfs_lock){+.+.}-{3:3}, at: queue_attr_store+0x148/0x1e0
[    8.760411]  #4: ffff888110dc7680 (&q->q_usage_counter(io)#27){++++}-{0:0}, at: blk_mq_freeze_queue_nomemsave+0x12/0x30
[    8.760416]  #5: ffff888110dc76b8 (&q->q_usage_counter(queue)#27){++++}-{0:0}, at: blk_mq_freeze_queue_nomemsave+0x12/0x30
[    8.760421]
               stack backtrace:
[    8.760422] CPU: 7 UID: 0 PID: 674 Comm: (udev-worker) Tainted: G     U             6.14.0-rc6-xe+ #7
[    8.760424] Tainted: [U]=USER
[    8.760425] Hardware name: ASUS System Product Name/PRIME B560M-A AC, BIOS 2001 02/01/2023
[    8.760426] Call Trace:
[    8.760427]  <TASK>
[    8.760428]  dump_stack_lvl+0x6e/0xa0
[    8.760431]  dump_stack+0x10/0x18
[    8.760433]  print_circular_bug.cold+0x17a/0x1b7
[    8.760437]  check_noncircular+0x13a/0x150
[    8.760441]  ? save_trace+0x54/0x360
[    8.760445]  __lock_acquire+0x1525/0x2760
[    8.760446]  ? irqentry_exit+0x3a/0xb0
[    8.760448]  ? sysvec_apic_timer_interrupt+0x57/0xc0
[    8.760452]  lock_acquire+0xca/0x310
[    8.760453]  ? kernfs_remove+0x32/0x60
[    8.760457]  down_write+0x3e/0xf0
[    8.760459]  ? kernfs_remove+0x32/0x60
[    8.760460]  kernfs_remove+0x32/0x60
[    8.760462]  sysfs_remove_dir+0x4f/0x60
[    8.760464]  __kobject_del+0x33/0xa0
[    8.760466]  kobject_del+0x13/0x30
[    8.760467]  elv_unregister_queue+0x52/0x80
[    8.760470]  elevator_switch+0x68/0x360
[    8.760472]  elv_iosched_store+0x14b/0x1b0
[    8.760475]  queue_attr_store+0x181/0x1e0
[    8.760479]  ? lock_acquire+0xca/0x310
[    8.760480]  ? kernfs_fop_write_iter+0x13f/0x250
[    8.760482]  ? lock_is_held_type+0xa3/0x130
[    8.760485]  sysfs_kf_write+0x49/0x80
[    8.760487]  kernfs_fop_write_iter+0x17d/0x250
[    8.760489]  vfs_write+0x281/0x540
[    8.760494]  ksys_write+0x72/0xf0
[    8.760497]  __x64_sys_write+0x19/0x30
[    8.760499]  x64_sys_call+0x2a3/0x2310
[    8.760502]  do_syscall_64+0x91/0x180
[    8.760504]  ? trace_hardirqs_off+0x5d/0xe0
[    8.760506]  ? handle_softirqs+0x479/0x4d0
[    8.760508]  ? hrtimer_interrupt+0x13f/0x280
[    8.760511]  ? irqentry_exit_to_user_mode+0x8b/0x260
[    8.760513]  ? clear_bhb_loop+0x15/0x70
[    8.760515]  ? clear_bhb_loop+0x15/0x70
[    8.760516]  ? clear_bhb_loop+0x15/0x70
[    8.760518]  entry_SYSCALL_64_after_hwframe+0x76/0x7e
[    8.760520] RIP: 0033:0x7aa3bf2f5504
[    8.760522] Code: c7 00 16 00 00 00 b8 ff ff ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 f3 0f 1e fa 80 3d c5 8b 10 00 00 74 13 b8 01 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 54 c3 0f 1f 00 55 48 89 e5 48 83 ec 20 48 89
[    8.760523] RSP: 002b:00007ffc1e3697d8 EFLAGS: 00000202 ORIG_RAX: 0000000000000001
[    8.760526] RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 00007aa3bf2f5504
[    8.760527] RDX: 0000000000000003 RSI: 00007ffc1e369ae0 RDI: 000000000000001c
[    8.760528] RBP: 00007ffc1e369800 R08: 00007aa3bf3f51c8 R09: 00007ffc1e3698b0
[    8.760528] R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000003
[    8.760529] R13: 00007ffc1e369ae0 R14: 0000613ccf21f2f0 R15: 00007aa3bf3f4e80
[    8.760533]  </TASK>

v2:
- Update a code comment to increase readability (Ming Lei).

Cc: Jens Axboe <axboe@kernel.dk>
Cc: linux-block@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Cc: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Thomas Hellström <thomas.hellstrom@linux.intel.com>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Link: https://lore.kernel.org/r/20250318095548.5187-1-thomas.hellstrom@linux.intel.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
alobakin pushed a commit that referenced this pull request Apr 1, 2025
perf test 11 hwmon fails on s390 with this error

 # ./perf test -Fv 11
 --- start ---
 ---- end ----
 11.1: Basic parsing test             : Ok
 --- start ---
 Testing 'temp_test_hwmon_event1'
 Using CPUID IBM,3931,704,A01,3.7,002f
 temp_test_hwmon_event1 -> hwmon_a_test_hwmon_pmu/temp_test_hwmon_event1/
 FAILED tests/hwmon_pmu.c:189 Unexpected config for
    'temp_test_hwmon_event1', 292470092988416 != 655361
 ---- end ----
 11.2: Parsing without PMU name       : FAILED!
 --- start ---
 Testing 'hwmon_a_test_hwmon_pmu/temp_test_hwmon_event1/'
 FAILED tests/hwmon_pmu.c:189 Unexpected config for
    'hwmon_a_test_hwmon_pmu/temp_test_hwmon_event1/',
    292470092988416 != 655361
 ---- end ----
 11.3: Parsing with PMU name          : FAILED!
 #

The root cause is in member test_event::config which is initialized
to 0xA0001 or 655361. During event parsing a long list event parsing
functions are called and end up with this gdb call stack:

 #0  hwmon_pmu__config_term (hwm=0x168dfd0, attr=0x3ffffff5ee8,
	term=0x168db60, err=0x3ffffff81c8) at util/hwmon_pmu.c:623
 #1  hwmon_pmu__config_terms (pmu=0x168dfd0, attr=0x3ffffff5ee8,
	terms=0x3ffffff5ea8, err=0x3ffffff81c8) at util/hwmon_pmu.c:662
 #2  0x00000000012f870c in perf_pmu__config_terms (pmu=0x168dfd0,
	attr=0x3ffffff5ee8, terms=0x3ffffff5ea8, zero=false,
	apply_hardcoded=false, err=0x3ffffff81c8) at util/pmu.c:1519
 #3  0x00000000012f88a4 in perf_pmu__config (pmu=0x168dfd0, attr=0x3ffffff5ee8,
	head_terms=0x3ffffff5ea8, apply_hardcoded=false, err=0x3ffffff81c8)
	at util/pmu.c:1545
 #4  0x00000000012680c4 in parse_events_add_pmu (parse_state=0x3ffffff7fb8,
	list=0x168dc00, pmu=0x168dfd0, const_parsed_terms=0x3ffffff6090,
	auto_merge_stats=true, alternate_hw_config=10)
	at util/parse-events.c:1508
 #5  0x00000000012684c6 in parse_events_multi_pmu_add (parse_state=0x3ffffff7fb8,
	event_name=0x168ec10 "temp_test_hwmon_event1", hw_config=10,
	const_parsed_terms=0x0, listp=0x3ffffff6230, loc_=0x3ffffff70e0)
	at util/parse-events.c:1592
 #6  0x00000000012f0e4e in parse_events_parse (_parse_state=0x3ffffff7fb8,
	scanner=0x16878c0) at util/parse-events.y:293
 #7  0x00000000012695a0 in parse_events__scanner (str=0x3ffffff81d8
	"temp_test_hwmon_event1", input=0x0, parse_state=0x3ffffff7fb8)
	at util/parse-events.c:1867
 #8  0x000000000126a1e8 in __parse_events (evlist=0x168b580,
	str=0x3ffffff81d8 "temp_test_hwmon_event1", pmu_filter=0x0,
	err=0x3ffffff81c8, fake_pmu=false, warn_if_reordered=true,
	fake_tp=false) at util/parse-events.c:2136
 #9  0x00000000011e36aa in parse_events (evlist=0x168b580,
	str=0x3ffffff81d8 "temp_test_hwmon_event1", err=0x3ffffff81c8)
	at /root/linux/tools/perf/util/parse-events.h:41
 #10 0x00000000011e3e64 in do_test (i=0, with_pmu=false, with_alias=false)
	at tests/hwmon_pmu.c:164
 #11 0x00000000011e422c in test__hwmon_pmu (with_pmu=false)
	at tests/hwmon_pmu.c:219
 #12 0x00000000011e431c in test__hwmon_pmu_without_pmu (test=0x1610368
	<suite.hwmon_pmu>, subtest=1) at tests/hwmon_pmu.c:23

where the attr::config is set to value 292470092988416 or 0x10a0000000000
in line 625 of file ./util/hwmon_pmu.c:

   attr->config = key.type_and_num;

However member key::type_and_num is defined as union and bit field:

   union hwmon_pmu_event_key {
        long type_and_num;
        struct {
                int num :16;
                enum hwmon_type type :8;
        };
   };

s390 is big endian and Intel is little endian architecture.
The events for the hwmon dummy pmu have num = 1 or num = 2 and
type is set to HWMON_TYPE_TEMP (which is 10).
On s390 this assignes member key::type_and_num the value of
0x10a0000000000 (which is 292470092988416) as shown in above
trace output.

Fix this and export the structure/union hwmon_pmu_event_key
so the test shares the same implementation as the event parsing
functions for union and bit fields. This should avoid
endianess issues on all platforms.

Output after:
 # ./perf test -F 11
 11.1: Basic parsing test         : Ok
 11.2: Parsing without PMU name   : Ok
 11.3: Parsing with PMU name      : Ok
 #

Fixes: 531ee0f ("perf test: Add hwmon "PMU" test")
Signed-off-by: Thomas Richter <tmricht@linux.ibm.com>
Reviewed-by: Ian Rogers <irogers@google.com>
Link: https://lore.kernel.org/r/20250131112400.568975-1-tmricht@linux.ibm.com
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
alobakin pushed a commit that referenced this pull request Apr 1, 2025
Ian told me that there are many memory leaks in the hierarchy mode.  I
can easily reproduce it with the follwing command.

  $ make DEBUG=1 EXTRA_CFLAGS=-fsanitize=leak

  $ perf record --latency -g -- ./perf test -w thloop

  $ perf report -H --stdio
  ...
  Indirect leak of 168 byte(s) in 21 object(s) allocated from:
      #0 0x7f3414c16c65 in malloc ../../../../src/libsanitizer/lsan/lsan_interceptors.cpp:75
      #1 0x55ed3602346e in map__get util/map.h:189
      #2 0x55ed36024cc4 in hist_entry__init util/hist.c:476
      #3 0x55ed36025208 in hist_entry__new util/hist.c:588
      #4 0x55ed36027c05 in hierarchy_insert_entry util/hist.c:1587
      #5 0x55ed36027e2e in hists__hierarchy_insert_entry util/hist.c:1638
      #6 0x55ed36027fa4 in hists__collapse_insert_entry util/hist.c:1685
      #7 0x55ed360283e8 in hists__collapse_resort util/hist.c:1776
      #8 0x55ed35de0323 in report__collapse_hists /home/namhyung/project/linux/tools/perf/builtin-report.c:735
      #9 0x55ed35de15b4 in __cmd_report /home/namhyung/project/linux/tools/perf/builtin-report.c:1119
      #10 0x55ed35de43dc in cmd_report /home/namhyung/project/linux/tools/perf/builtin-report.c:1867
      #11 0x55ed35e66767 in run_builtin /home/namhyung/project/linux/tools/perf/perf.c:351
      #12 0x55ed35e66a0e in handle_internal_command /home/namhyung/project/linux/tools/perf/perf.c:404
      #13 0x55ed35e66b67 in run_argv /home/namhyung/project/linux/tools/perf/perf.c:448
      #14 0x55ed35e66eb0 in main /home/namhyung/project/linux/tools/perf/perf.c:556
      #15 0x7f340ac33d67 in __libc_start_call_main ../sysdeps/nptl/libc_start_call_main.h:58
  ...

  $ perf report -H --stdio 2>&1 | grep -c '^Indirect leak'
  93

I found that hist_entry__delete() missed to release child entries in the
hierarchy tree (hroot_{in,out}).  It needs to iterate the child entries
and call hist_entry__delete() recursively.

After this change:

  $ perf report -H --stdio 2>&1 | grep -c '^Indirect leak'
  0

Reported-by: Ian Rogers <irogers@google.com>
Tested-by Thomas Falcon <thomas.falcon@intel.com>
Reviewed-by: Ian Rogers <irogers@google.com>
Link: https://lore.kernel.org/r/20250307061250.320849-2-namhyung@kernel.org
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
alobakin pushed a commit that referenced this pull request Apr 1, 2025
The env.pmu_mapping can be leaked when it reads data from a pipe on AMD.
For a pipe data, it reads the header data including pmu_mapping from
PERF_RECORD_HEADER_FEATURE runtime.  But it's already set in:

  perf_session__new()
    __perf_session__new()
      evlist__init_trace_event_sample_raw()
        evlist__has_amd_ibs()
          perf_env__nr_pmu_mappings()

Then it'll overwrite that when it processes the HEADER_FEATURE record.
Here's a report from address sanitizer.

  Direct leak of 2689 byte(s) in 1 object(s) allocated from:
    #0 0x7fed8f814596 in realloc ../../../../src/libsanitizer/lsan/lsan_interceptors.cpp:98
    #1 0x5595a7d416b1 in strbuf_grow util/strbuf.c:64
    #2 0x5595a7d414ef in strbuf_init util/strbuf.c:25
    #3 0x5595a7d0f4b7 in perf_env__read_pmu_mappings util/env.c:362
    #4 0x5595a7d12ab7 in perf_env__nr_pmu_mappings util/env.c:517
    #5 0x5595a7d89d2f in evlist__has_amd_ibs util/amd-sample-raw.c:315
    #6 0x5595a7d87fb2 in evlist__init_trace_event_sample_raw util/sample-raw.c:23
    #7 0x5595a7d7f893 in __perf_session__new util/session.c:179
    #8 0x5595a7b79572 in perf_session__new util/session.h:115
    #9 0x5595a7b7e9dc in cmd_report builtin-report.c:1603
    #10 0x5595a7c019eb in run_builtin perf.c:351
    #11 0x5595a7c01c92 in handle_internal_command perf.c:404
    #12 0x5595a7c01deb in run_argv perf.c:448
    #13 0x5595a7c02134 in main perf.c:556
    #14 0x7fed85833d67 in __libc_start_call_main ../sysdeps/nptl/libc_start_call_main.h:58

Let's free the existing pmu_mapping data if any.

Cc: Ravi Bangoria <ravi.bangoria@amd.com>
Link: https://lore.kernel.org/r/20250311000416.817631-1-namhyung@kernel.org
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
alobakin pushed a commit that referenced this pull request Apr 3, 2025
When a bio with REQ_PREFLUSH is submitted to dm, __send_empty_flush()
generates a flush_bio with REQ_OP_WRITE | REQ_PREFLUSH | REQ_SYNC,
which causes the flush_bio to be throttled by wbt_wait().

An example from v5.4, similar problem also exists in upstream:

    crash> bt 2091206
    PID: 2091206  TASK: ffff2050df92a300  CPU: 109  COMMAND: "kworker/u260:0"
     #0 [ffff800084a2f7f0] __switch_to at ffff80004008aeb8
     #1 [ffff800084a2f820] __schedule at ffff800040bfa0c4
     #2 [ffff800084a2f880] schedule at ffff800040bfa4b4
     #3 [ffff800084a2f8a0] io_schedule at ffff800040bfa9c4
     #4 [ffff800084a2f8c0] rq_qos_wait at ffff8000405925bc
     #5 [ffff800084a2f940] wbt_wait at ffff8000405bb3a0
     #6 [ffff800084a2f9a0] __rq_qos_throttle at ffff800040592254
     #7 [ffff800084a2f9c0] blk_mq_make_request at ffff80004057cf38
     #8 [ffff800084a2fa60] generic_make_request at ffff800040570138
     #9 [ffff800084a2fae0] submit_bio at ffff8000405703b4
    #10 [ffff800084a2fb50] xlog_write_iclog at ffff800001280834 [xfs]
    #11 [ffff800084a2fbb0] xlog_sync at ffff800001280c3c [xfs]
    #12 [ffff800084a2fbf0] xlog_state_release_iclog at ffff800001280df4 [xfs]
    #13 [ffff800084a2fc10] xlog_write at ffff80000128203c [xfs]
    #14 [ffff800084a2fcd0] xlog_cil_push at ffff8000012846dc [xfs]
    #15 [ffff800084a2fda0] xlog_cil_push_work at ffff800001284a2c [xfs]
    #16 [ffff800084a2fdb0] process_one_work at ffff800040111d08
    #17 [ffff800084a2fe00] worker_thread at ffff8000401121cc
    #18 [ffff800084a2fe70] kthread at ffff800040118de4

After commit 2def284 ("xfs: don't allow log IO to be throttled"),
the metadata submitted by xlog_write_iclog() should not be throttled.
But due to the existence of the dm layer, throttling flush_bio indirectly
causes the metadata bio to be throttled.

Fix this by conditionally adding REQ_IDLE to flush_bio.bi_opf, which makes
wbt_should_throttle() return false to avoid wbt_wait().

Signed-off-by: Jinliang Zheng <alexjlzheng@tencent.com>
Reviewed-by: Tianxiang Peng <txpeng@tencent.com>
Reviewed-by: Hao Peng <flyingpeng@tencent.com>
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
alobakin pushed a commit that referenced this pull request Apr 3, 2025
…ge_order()

Patch series "mm: MM owner tracking for large folios (!hugetlb) +
CONFIG_NO_PAGE_MAPCOUNT", v3.

Let's add an "easy" way to decide -- without false positives, without
page-mapcounts and without page table/rmap scanning -- whether a large
folio is "certainly mapped exclusively" into a single MM, or whether it
"maybe mapped shared" into multiple MMs.

Use that information to implement Copy-on-Write reuse, to convert
folio_likely_mapped_shared() to folio_maybe_mapped_share(), and to
introduce a kernel config option that lets us not use+maintain per-page
mapcounts in large folios anymore.

The bigger picture was presented at LSF/MM [1].

This series is effectively a follow-up on my early work [2], which
implemented a more precise, but also more complicated, way to identify
whether a large folio is "mapped shared" into multiple MMs or "mapped
exclusively" into a single MM.


1 Patch Organization
====================

Patch #1 -> #6: make more room in order-1 folios, so we have two
                "unsigned long" available for our purposes

Patch #7 -> #11: preparations

Patch #12: MM owner tracking for large folios

Patch #13: COW reuse for PTE-mapped anon THP

Patch #14: folio_maybe_mapped_shared()

Patch #15 -> #20: introduce and implement CONFIG_NO_PAGE_MAPCOUNT


2 MM owner tracking
===================

We assign each MM a unique ID ("MM ID"), to be able to squeeze more
information in our folios.  On 32bit we use 15-bit IDs, on 64bit we use
31-bit IDs.

For each large folios, we now store two MM-ID+mapcount ("slot")
combinations:
* mm0_id + mm0_mapcount
* mm1_id + mm1_mapcount

On 32bit, we use a 16-bit per-MM mapcount, on 64bit an ordinary 32bit
mapcount.  This way, we require 2x "unsigned long" on 32bit and 64bit for
both slots.

Paired with the large mapcount, we can reliably identify whether one of
these MMs is the current owner (-> owns all mappings) or even holds all
folio references (-> owns all mappings, and all references are from
mappings).

As long as only two MMs map folio pages at a time, we can reliably and
precisely identify whether a large folio is "mapped shared" or "mapped
exclusively".

Any additional MM that starts mapping the folio while there are no free
slots becomes an "untracked MM".  If one such "untracked MM" is the last
one mapping a folio exclusively, we will not detect the folio as "mapped
exclusively" but instead as "maybe mapped shared".  (exception: only a
single mapping remains)

So that's where the approach gets imprecise.

For now, we use a bit-spinlock to sync the large mapcount + slots, and
make sure we do keep the machinery fast, to not degrade (un)map
performance drastically: for example, we make sure to only use a single
atomic (when grabbing the bit-spinlock), like we would already perform
when updating the large mapcount.


3 CONFIG_NO_PAGE_MAPCOUNT
=========================

patch #15 -> #20 spell out and document what exactly is affected when not
maintaining the per-page mapcounts in large folios anymore.

Most importantly, as we cannot maintain folio->_nr_pages_mapped anymore
when (un)mapping pages, we'll account a complete folio as mapped if a
single page is mapped.  In addition, we'll not detect partially mapped
anonymous folios as such in all cases yet.

Likely less relevant changes include that we might now under-estimate the
USS (Unique Set Size) of a process, but never over-estimate it.

The goal is to make CONFIG_NO_PAGE_MAPCOUNT the default at some point, to
then slowly make it the only option, as we learn about real-life impacts
and possible ways to mitigate them.


4 Performance
=============

Detailed performance numbers were included in v1 [3], and not that much
changed between v1 and v2.

I did plenty of measurements on different systems in the meantime, that
all revealed slightly different results.

The pte-mapped-folio micro-benchmarks [4] are fairly sensitive to code
layout changes on some systems.  Especially the fork() benchmark started
being more-shaky-than-before on recent kernels for some reason.

In summary, with my micro-benchmarks:

* Small folios are not impacted.

* CoW performance seems to be mostly unchanged across all folios sizes.

* CoW reuse performance of large folios now matches CoW reuse
  performance of small folios, because we now actually implement the CoW
  reuse optimization.  On an Intel Xeon Silver 4210R I measured a ~65%
  reduction in runtime, on an arm64 system I measured ~54% reduction.

* munmap() performance improves with CONFIG_NO_PAGE_MAPCOUNT.  I saw
  double-digit % reduction (up to ~30% on an Intel Xeon Silver 4210R and
  up to ~70% on an AmpereOne A192-32X) with larger folios.  The larger the
  folios, the larger the performance improvement.

* munmao() performance very slightly (couple percent) degrades without
  CONFIG_NO_PAGE_MAPCOUNT for smaller folios.  For larger folios, there
  seems to be no change at all.

* fork() performance improves with CONFIG_NO_PAGE_MAPCOUNT.  I saw
  double-digit % reduction (up to ~20% on an Intel Xeon Silver 4210R and
  up to ~10% on an AmpereOne A192-32X) with larger folios.  The larger the
  folios, the larger the performance improvement.

* While fork() performance without CONFIG_NO_PAGE_MAPCOUNT seems to be
  almost unchanged on some systems, I saw some degradation for smaller
  folios on the AmpereOne A192-32X.  I did not investigate the details
  yet, but I suspect code layout changes or suboptimal code placement /
  inlining.

I'm not to worried about the fork() micro-benchmarks for smaller folios
given how shaky the results are lately and by how much we improved fork()
performance recently.

I also ran case-anon-cow-rand and case-anon-cow-seq part of
vm-scalability, to assess the scalability and the impact of the
bit-spinlock.  My measurements on a two 2-socket 10-core Intel Xeon Silver
4210R CPU revealed no significant changes.

Similarly, running these benchmarks with 2 MiB THPs enabled on the
AmpereOne A192-32X with 192 cores, I got < 1% difference with < 1% stdev,
which is nice.

So far, I did not get my hands on a similarly large system with multiple
sockets.

I found no other fitting scalability benchmarks that seem to really hammer
on concurrent mapping/unmapping of large folio pages like
case-anon-cow-seq does.


5 Concerns
==========

5.1 Bit spinlock
----------------

I'm not quite happy about the bit-spinlock, but so far it does not seem to
affect scalability in my measurements.

If it ever becomes a problem we could either investigate improving the
locking, or simply stopping the MM tracking once there are "too many
mappings" and simply assume that the folio is "mapped shared" until it was
freed.

This would be similar (but slightly different) to the "0,1,2,stopped"
counting idea Willy had at some point.  Adding that logic to "stop
tracking" adds more code to the hot path, so I avoided that for now.


5.2 folio_maybe_mapped_shared()
-------------------------------

I documented the change from folio_likely_mapped_shared() to
folio_maybe_mapped_shared() quite extensively.  If we run into surprises,
I have some ideas on how to resolve them.  For now, I think we should be
fine.


5.3 Added code to map/unmap hot path
------------------------------------

So far, it looks like the added code on the rmap hot path does not really
seem to matter much in the bigger picture.  I'd like to further reduce it
(and possibly improve fork() performance further), but I don't easily see
how right now.  Well, and I am out of puff 🙂

Having that said, alternatives I considered (e.g., per-MM per-folio
mapcount) would add a lot more overhead to these hot paths.


6 Future Work
=============

6.1 Large mapcount
------------------

It would be very handy if the large mapcount would count how often folio
pages are actually mapped into page tables: a PMD on x86-64 would count
512 times.  Calculating the average per-page mapcount will be easy, and
remapping (PMD->PTE) folios would get even faster.

That would also remove the need for the entire mapcount (except for
PMD-sized folios for memory statistics reasons ...), and allow for mapping
folios larger than PMDs (e.g., 4 MiB) easily.

We likely would also have to take the same number of folio references to
make our folio_mapcount() == folio_ref_count() work, and we'd want to be
able to avoid mapcount+refcount overflows: this could already become an
issue with pte-mapped PUD-sized folios (fsdax).

One approach we discussed in the THP cabal meeting is (1) extending the
mapcount for large folios to 64bit (at least on 64bit systems) and (2)
keeping the refcount at 32bit, but (3) having exactly one reference if the
the mapcount != 0.

It should be doable, but there are some corner cases to consider on the
unmap path; it is something that I will be looking into next.


6.2 hugetlb
-----------

I'd love to make use of the same tracking also for hugetlb.

The real problem is PMD table sharing: getting a page mapped by MM X and
unmapped by MM Y will not work.  With mshare, that problem should not
exist (all mapping/unmapping will be routed through the mshare MM).

[1] https://lwn.net/Articles/974223/
[2] https://lore.kernel.org/linux-mm/a9922f58-8129-4f15-b160-e0ace581bcbe@redhat.com/T/
[3] https://lkml.kernel.org/r/20240829165627.2256514-1-david@redhat.com
[4] https://gitlab.com/davidhildenbrand/scratchspace/-/raw/main/pte-mapped-folio-benchmarks.c


This patch (of 20):

Let's factor it out into a simple helper function.  This helper will also
come in handy when working with code where we know that our folio is
large.

Maybe in the future we'll have the order readily available for small and
large folios; in that case, folio_large_order() would simply translate to
folio_order().

Link: https://lkml.kernel.org/r/20250303163014.1128035-1-david@redhat.com
Link: https://lkml.kernel.org/r/20250303163014.1128035-2-david@redhat.com
Signed-off-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Lance Yang <ioworker0@gmail.com>
Reviewed-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Andy Lutomirks^H^Hski <luto@kernel.org>
Cc: Borislav Betkov <bp@alien8.de>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jann Horn <jannh@google.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Liam Howlett <liam.howlett@oracle.com>
Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Cc: Matthew Wilcow (Oracle) <willy@infradead.org>
Cc: Michal Koutn <mkoutny@suse.com>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: tejun heo <tj@kernel.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Zefan Li <lizefan.x@bytedance.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
alobakin pushed a commit that referenced this pull request Apr 11, 2025
In ThinPro, we use the convention <upstream_ver>+hp<patchlevel> for
the kernel package. This does not have a dash in the name or version.
This is built by editing ".version" before a build, and setting
EXTRAVERSION="+hp" and KDEB_PKGVERSION make variables:

    echo 68 > .version
    make -j<n> EXTRAVERSION="+hp" bindeb-pkg KDEB_PKGVERSION=6.12.2+hp69

    .deb name: linux-image-6.12.2+hp_6.12.2+hp69_amd64.deb

Since commit 7d4f07d ("kbuild: deb-pkg: squash
scripts/package/deb-build-option to debian/rules"), this no longer
works. The deb build logic changed, even though, the commit message
implies that the logic should be unmodified.

Before, KBUILD_BUILD_VERSION was not set if the KDEB_PKGVERSION did
not contain a dash. After the change KBUILD_BUILD_VERSION is always
set to KDEB_PKGVERSION. Since this determines UTS_VERSION, the uname
output to look off:

    (now)      uname -a: version 6.12.2+hp ... #6.12.2+hp69
    (expected) uname -a: version 6.12.2+hp ... torvalds#69

Update the debian/rules logic to restore the original behavior.

Fixes: 7d4f07d ("kbuild: deb-pkg: squash scripts/package/deb-build-option to debian/rules")
Signed-off-by: Alexandru Gagniuc <alexandru.gagniuc@hp.com>
Reviewed-by: Nicolas Schier <nicolas@fjasle.eu>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
alobakin pushed a commit that referenced this pull request May 12, 2025
syzkaller triggered an oversized kvmalloc() warning.
Silence it by adding __GFP_NOWARN.

syzkaller log:
 WARNING: CPU: 7 PID: 518 at mm/util.c:665 __kvmalloc_node_noprof+0x175/0x180
 CPU: 7 UID: 0 PID: 518 Comm: c_repro Not tainted 6.11.0-rc6+ #6
 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.13.0-0-gf21b5a4aeb02-prebuilt.qemu.org 04/01/2014
 RIP: 0010:__kvmalloc_node_noprof+0x175/0x180
 RSP: 0018:ffffc90001e67c10 EFLAGS: 00010246
 RAX: 0000000000000100 RBX: 0000000000000400 RCX: ffffffff8149d46b
 RDX: 0000000000000000 RSI: ffff8881030fae80 RDI: 0000000000000002
 RBP: 000000712c800000 R08: 0000000000000100 R09: 0000000000000000
 R10: ffffc90001e67c10 R11: 0030ae0601000000 R12: 0000000000000000
 R13: 0000000000000000 R14: 00000000ffffffff R15: 0000000000000000
 FS:  00007fde79159740(0000) GS:ffff88813bdc0000(0000) knlGS:0000000000000000
 CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
 CR2: 0000000020000180 CR3: 0000000105eb4005 CR4: 00000000003706b0
 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
 Call Trace:
  <TASK>
  ib_umem_odp_get+0x1f6/0x390
  mlx5_ib_reg_user_mr+0x1e8/0x450
  ib_uverbs_reg_mr+0x28b/0x440
  ib_uverbs_write+0x7d3/0xa30
  vfs_write+0x1ac/0x6c0
  ksys_write+0x134/0x170
  ? __sanitizer_cov_trace_pc+0x1c/0x50
  do_syscall_64+0x50/0x110
  entry_SYSCALL_64_after_hwframe+0x76/0x7e

Fixes: 3782495 ("RDMA/odp: Use kvcalloc for the dma_list and page_list")
Signed-off-by: Shay Drory <shayd@nvidia.com>
Link: https://patch.msgid.link/c6cb92379de668be94894f49c2cfa40e73f94d56.1742388096.git.leonro@nvidia.com
Signed-off-by: Leon Romanovsky <leon@kernel.org>
alobakin pushed a commit that referenced this pull request May 12, 2025
As shown in [1], it is possible to corrupt a BPF ELF file such that
arbitrary BPF instructions are loaded by libbpf. This can be done by
setting a symbol (BPF program) section offset to a large (unsigned)
number such that <section start + symbol offset> overflows and points
before the section data in the memory.

Consider the situation below where:
- prog_start = sec_start + symbol_offset    <-- size_t overflow here
- prog_end   = prog_start + prog_size

    prog_start        sec_start        prog_end        sec_end
        |                |                 |              |
        v                v                 v              v
    .....................|################################|............

The report in [1] also provides a corrupted BPF ELF which can be used as
a reproducer:

    $ readelf -S crash
    Section Headers:
      [Nr] Name              Type             Address           Offset
           Size              EntSize          Flags  Link  Info  Align
    ...
      [ 2] uretprobe.mu[...] PROGBITS         0000000000000000  00000040
           0000000000000068  0000000000000000  AX       0     0     8

    $ readelf -s crash
    Symbol table '.symtab' contains 8 entries:
       Num:    Value          Size Type    Bind   Vis      Ndx Name
    ...
         6: ffffffffffffffb8   104 FUNC    GLOBAL DEFAULT    2 handle_tp

Here, the handle_tp prog has section offset ffffffffffffffb8, i.e. will
point before the actual memory where section 2 is allocated.

This is also reported by AddressSanitizer:

    =================================================================
    ==1232==ERROR: AddressSanitizer: heap-buffer-overflow on address 0x7c7302fe0000 at pc 0x7fc3046e4b77 bp 0x7ffe64677cd0 sp 0x7ffe64677490
    READ of size 104 at 0x7c7302fe0000 thread T0
        #0 0x7fc3046e4b76 in memcpy (/lib64/libasan.so.8+0xe4b76)
        #1 0x00000040df3e in bpf_object__init_prog /src/libbpf/src/libbpf.c:856
        #2 0x00000040df3e in bpf_object__add_programs /src/libbpf/src/libbpf.c:928
        #3 0x00000040df3e in bpf_object__elf_collect /src/libbpf/src/libbpf.c:3930
        #4 0x00000040df3e in bpf_object_open /src/libbpf/src/libbpf.c:8067
        #5 0x00000040f176 in bpf_object__open_file /src/libbpf/src/libbpf.c:8090
        #6 0x000000400c16 in main /poc/poc.c:8
        #7 0x7fc3043d25b4 in __libc_start_call_main (/lib64/libc.so.6+0x35b4)
        #8 0x7fc3043d2667 in __libc_start_main@@GLIBC_2.34 (/lib64/libc.so.6+0x3667)
        #9 0x000000400b34 in _start (/poc/poc+0x400b34)

    0x7c7302fe0000 is located 64 bytes before 104-byte region [0x7c7302fe0040,0x7c7302fe00a8)
    allocated by thread T0 here:
        #0 0x7fc3046e716b in malloc (/lib64/libasan.so.8+0xe716b)
        #1 0x7fc3045ee600 in __libelf_set_rawdata_wrlock (/lib64/libelf.so.1+0xb600)
        #2 0x7fc3045ef018 in __elf_getdata_rdlock (/lib64/libelf.so.1+0xc018)
        #3 0x00000040642f in elf_sec_data /src/libbpf/src/libbpf.c:3740

The problem here is that currently, libbpf only checks that the program
end is within the section bounds. There used to be a check
`while (sec_off < sec_sz)` in bpf_object__add_programs, however, it was
removed by commit 6245947 ("libbpf: Allow gaps in BPF program
sections to support overriden weak functions").

Add a check for detecting the overflow of `sec_off + prog_sz` to
bpf_object__init_prog to fix this issue.

[1] https://github.com/lmarch2/poc/blob/main/libbpf/libbpf.md

Fixes: 6245947 ("libbpf: Allow gaps in BPF program sections to support overriden weak functions")
Reported-by: lmarch2 <2524158037@qq.com>
Signed-off-by: Viktor Malik <vmalik@redhat.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Reviewed-by: Shung-Hsi Yu <shung-hsi.yu@suse.com>
Link: https://github.com/lmarch2/poc/blob/main/libbpf/libbpf.md
Link: https://lore.kernel.org/bpf/20250415155014.397603-1-vmalik@redhat.com
alobakin pushed a commit that referenced this pull request May 12, 2025
Ido Schimmel says:

====================
vxlan: Convert FDB table to rhashtable

The VXLAN driver currently stores FDB entries in a hash table with a
fixed number of buckets (256), resulting in reduced performance as the
number of entries grows. This patchset solves the issue by converting
the driver to use rhashtable which maintains a more or less constant
performance regardless of the number of entries.

Measured transmitted packets per second using a single pktgen thread
with varying number of entries when the transmitted packet always hits
the default entry (worst case):

Number of entries | Improvement
------------------|------------
1k                | +1.12%
4k                | +9.22%
16k               | +55%
64k               | +585%
256k              | +2460%

The first patches are preparations for the conversion in the last patch.
Specifically, the series is structured as follows:

Patch #1 adds RCU read-side critical sections in the Tx path when
accessing FDB entries. Targeting at net-next as I am not aware of any
issues due to this omission despite the code being structured that way
for a long time. Without it, traces will be generated when converting
FDB lookup to rhashtable_lookup().

Patch #2-#5 simplify the creation of the default FDB entry (all-zeroes).
Current code assumes that insertion into the hash table cannot fail,
which will no longer be true with rhashtable.

Patches #6-#10 add FDB entries to a linked list for entry traversal
instead of traversing over them using the fixed size hash table which is
removed in the last patch.

Patches #11-#12 add wrappers for FDB lookup that make it clear when each
should be used along with lockdep annotations. Needed as a preparation
for rhashtable_lookup() that must be called from an RCU read-side
critical section.

Patch #13 treats dst cache initialization errors as non-fatal. See more
info in the commit message. The current code happens to work because
insertion into the fixed size hash table is slow enough for the per-CPU
allocator to be able to create new chunks of per-CPU memory.

Patch #14 adds an FDB key structure that includes the MAC address and
source VNI. To be used as rhashtable key.

Patch #15 does the conversion to rhashtable.
====================

Link: https://patch.msgid.link/20250415121143.345227-1-idosch@nvidia.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
alobakin pushed a commit that referenced this pull request May 12, 2025
Commit 03df156 ("xdp: double protect netdev->xdp_flags with
netdev->lock") introduces the netdev lock to xdp_set_features_flag().
The change includes a _locked version of the method, as it is possible
for a driver to have already acquired the netdev lock before calling
this helper. However, the same applies to
xdp_features_(set|clear)_redirect_flags(), which ends up calling the
unlocked version of xdp_set_features_flags() leading to deadlocks in
GVE, which grabs the netdev lock as part of its suspend, reset, and
shutdown processes:

[  833.265543] WARNING: possible recursive locking detected
[  833.270949] 6.15.0-rc1 #6 Tainted: G            E
[  833.276271] --------------------------------------------
[  833.281681] systemd-shutdow/1 is trying to acquire lock:
[  833.287090] ffff949d2b148c68 (&dev->lock){+.+.}-{4:4}, at: xdp_set_features_flag+0x29/0x90
[  833.295470]
[  833.295470] but task is already holding lock:
[  833.301400] ffff949d2b148c68 (&dev->lock){+.+.}-{4:4}, at: gve_shutdown+0x44/0x90 [gve]
[  833.309508]
[  833.309508] other info that might help us debug this:
[  833.316130]  Possible unsafe locking scenario:
[  833.316130]
[  833.322142]        CPU0
[  833.324681]        ----
[  833.327220]   lock(&dev->lock);
[  833.330455]   lock(&dev->lock);
[  833.333689]
[  833.333689]  *** DEADLOCK ***
[  833.333689]
[  833.339701]  May be due to missing lock nesting notation
[  833.339701]
[  833.346582] 5 locks held by systemd-shutdow/1:
[  833.351205]  #0: ffffffffa9c89130 (system_transition_mutex){+.+.}-{4:4}, at: __se_sys_reboot+0xe6/0x210
[  833.360695]  #1: ffff93b399e5c1b8 (&dev->mutex){....}-{4:4}, at: device_shutdown+0xb4/0x1f0
[  833.369144]  #2: ffff949d19a471b8 (&dev->mutex){....}-{4:4}, at: device_shutdown+0xc2/0x1f0
[  833.377603]  #3: ffffffffa9eca050 (rtnl_mutex){+.+.}-{4:4}, at: gve_shutdown+0x33/0x90 [gve]
[  833.386138]  #4: ffff949d2b148c68 (&dev->lock){+.+.}-{4:4}, at: gve_shutdown+0x44/0x90 [gve]

Introduce xdp_features_(set|clear)_redirect_target_locked() versions
which assume that the netdev lock has already been acquired before
setting the XDP feature flag and update GVE to use the locked version.

Fixes: 03df156 ("xdp: double protect netdev->xdp_flags with netdev->lock")
Tested-by: Mina Almasry <almasrymina@google.com>
Reviewed-by: Willem de Bruijn <willemb@google.com>
Reviewed-by: Harshitha Ramamurthy <hramamurthy@google.com>
Signed-off-by: Joshua Washington <joshwash@google.com>
Acked-by: Stanislav Fomichev <sdf@fomichev.me>
Acked-by: Martin KaFai Lau <martin.lau@kernel.org>
Link: https://patch.msgid.link/20250422011643.3509287-1-joshwash@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
alobakin pushed a commit that referenced this pull request Jun 3, 2025
The platform profile driver is loaded even on platforms that do not have
ACPI enabled. The initialization of the sysfs entries was recently moved
from platform_profile_register() to the module init call, and those
entries need acpi_kobj to be initialized which is not the case when ACPI
is disabled.

This results in the following warning:

 WARNING: CPU: 5 PID: 1 at fs/sysfs/group.c:131 internal_create_group+0xa22/0xdd8
 Modules linked in:
 CPU: 5 UID: 0 PID: 1 Comm: swapper/0 Tainted: G        W           6.15.0-rc7-dirty #6 PREEMPT
 Tainted: [W]=WARN
 Hardware name: riscv-virtio,qemu (DT)
 epc : internal_create_group+0xa22/0xdd8
  ra : internal_create_group+0xa22/0xdd8

 Call Trace:

 internal_create_group+0xa22/0xdd8
 sysfs_create_group+0x22/0x2e
 platform_profile_init+0x74/0xb2
 do_one_initcall+0x198/0xa9e
 kernel_init_freeable+0x6d8/0x780
 kernel_init+0x28/0x24c
 ret_from_fork+0xe/0x18

Fix this by checking if ACPI is enabled before trying to create sysfs
entries.

Fixes: 77be5ca ("ACPI: platform_profile: Create class for ACPI platform profile")
Signed-off-by: Alexandre Ghiti <alexghiti@rivosinc.com>
Reviewed-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Mark Pearson <mpearson-lenovo@squebb.ca>
Link: https://patch.msgid.link/20250522141410.31315-1-alexghiti@rivosinc.com
[ rjw: Subject and changelog edits ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
alobakin pushed a commit that referenced this pull request Jun 3, 2025
Despite the fact that several lockdep-related checks are skipped when
calling trylock* versions of the locking primitives, for example
mutex_trylock, each time the mutex is acquired, a held_lock is still
placed onto the lockdep stack by __lock_acquire() which is called
regardless of whether the trylock* or regular locking API was used.

This means that if the caller successfully acquires more than
MAX_LOCK_DEPTH locks of the same class, even when using mutex_trylock,
lockdep will still complain that the maximum depth of the held lock stack
has been reached and disable itself.

For example, the following error currently occurs in the ARM version
of KVM, once the code tries to lock all vCPUs of a VM configured with more
than MAX_LOCK_DEPTH vCPUs, a situation that can easily happen on modern
systems, where having more than 48 CPUs is common, and it's also common to
run VMs that have vCPU counts approaching that number:

[  328.171264] BUG: MAX_LOCK_DEPTH too low!
[  328.175227] turning off the locking correctness validator.
[  328.180726] Please attach the output of /proc/lock_stat to the bug report
[  328.187531] depth: 48  max: 48!
[  328.190678] 48 locks held by qemu-kvm/11664:
[  328.194957]  #0: ffff800086de5ba0 (&kvm->lock){+.+.}-{3:3}, at: kvm_ioctl_create_device+0x174/0x5b0
[  328.204048]  #1: ffff0800e78800b8 (&vcpu->mutex){+.+.}-{3:3}, at: lock_all_vcpus+0x16c/0x2a0
[  328.212521]  #2: ffff07ffeee51e98 (&vcpu->mutex){+.+.}-{3:3}, at: lock_all_vcpus+0x16c/0x2a0
[  328.220991]  #3: ffff0800dc7d80b8 (&vcpu->mutex){+.+.}-{3:3}, at: lock_all_vcpus+0x16c/0x2a0
[  328.229463]  #4: ffff07ffe0c980b8 (&vcpu->mutex){+.+.}-{3:3}, at: lock_all_vcpus+0x16c/0x2a0
[  328.237934]  #5: ffff0800a3883c78 (&vcpu->mutex){+.+.}-{3:3}, at: lock_all_vcpus+0x16c/0x2a0
[  328.246405]  #6: ffff07fffbe480b8 (&vcpu->mutex){+.+.}-{3:3}, at: lock_all_vcpus+0x16c/0x2a0

Luckily, in all instances that require locking all vCPUs, the
'kvm->lock' is taken a priori, and that fact makes it possible to use
the little known feature of lockdep, called a 'nest_lock', to avoid this
warning and subsequent lockdep self-disablement.

The action of 'nested lock' being provided to lockdep's lock_acquire(),
causes the lockdep to detect that the top of the held lock stack contains
a lock of the same class and then increment its reference counter instead
of pushing a new held_lock item onto that stack.

See __lock_acquire for more information.

Signed-off-by: Maxim Levitsky <mlevitsk@redhat.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Message-ID: <20250512180407.659015-2-mlevitsk@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
alobakin pushed a commit that referenced this pull request Jun 3, 2025
Use kvm_trylock_all_vcpus instead of a custom implementation when locking
all vCPUs of a VM, to avoid triggering a lockdep warning, in the case in
which the VM is configured to have more than MAX_LOCK_DEPTH vCPUs.

This fixes the following false lockdep warning:

[  328.171264] BUG: MAX_LOCK_DEPTH too low!
[  328.175227] turning off the locking correctness validator.
[  328.180726] Please attach the output of /proc/lock_stat to the bug report
[  328.187531] depth: 48  max: 48!
[  328.190678] 48 locks held by qemu-kvm/11664:
[  328.194957]  #0: ffff800086de5ba0 (&kvm->lock){+.+.}-{3:3}, at: kvm_ioctl_create_device+0x174/0x5b0
[  328.204048]  #1: ffff0800e78800b8 (&vcpu->mutex){+.+.}-{3:3}, at: lock_all_vcpus+0x16c/0x2a0
[  328.212521]  #2: ffff07ffeee51e98 (&vcpu->mutex){+.+.}-{3:3}, at: lock_all_vcpus+0x16c/0x2a0
[  328.220991]  #3: ffff0800dc7d80b8 (&vcpu->mutex){+.+.}-{3:3}, at: lock_all_vcpus+0x16c/0x2a0
[  328.229463]  #4: ffff07ffe0c980b8 (&vcpu->mutex){+.+.}-{3:3}, at: lock_all_vcpus+0x16c/0x2a0
[  328.237934]  #5: ffff0800a3883c78 (&vcpu->mutex){+.+.}-{3:3}, at: lock_all_vcpus+0x16c/0x2a0
[  328.246405]  #6: ffff07fffbe480b8 (&vcpu->mutex){+.+.}-{3:3}, at: lock_all_vcpus+0x16c/0x2a0

Suggested-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Maxim Levitsky <mlevitsk@redhat.com>
Acked-by: Marc Zyngier <maz@kernel.org>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Message-ID: <20250512180407.659015-6-mlevitsk@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
alobakin pushed a commit that referenced this pull request Jun 18, 2025
Subbaraya Sundeep says:

====================
CN20K silicon with mbox support

CN20K is the next generation silicon in the Octeon series with various
improvements and new features.

Along with other changes the mailbox communication mechanism between RVU
(Resource virtualization Unit) SRIOV PFs/VFs with Admin function (AF) has
also gone through some changes.

Some of those changes are
- Separate IRQs for mbox request and response/ack.
- Configurable mbox size, default being 64KB.
- Ability for VFs to communicate with RVU AF instead of going through
  parent SRIOV PF.

Due to more memory requirement due to configurable mbox size, mbox memory
will now have to be allocated by
- AF (PF0) for communicating with other PFs and all VFs in the system.
- PF for communicating with it's child VFs.

On previous silicons mbox memory was reserved and configured by firmware.

This patch series add basic mbox support for AF (PF0) <=> PFs and
PF <=> VFs. AF <=> VFs communication and variable mbox size support will
come in later.

Patch #1 Supported co-existance of bit encoding PFs and VFs in 16-bit
         hardware pcifunc format between CN20K silicon and older octeon
         series. Also exported PF,VF masks and shifts present in mailbox
         module to all other modules.

Patch #2 Added basic mbox operation APIs and structures to support both
         CN20K and previous version of silicons.

Patch #3 This patch adds support for basic mbox infrastructure
         implementation for CN20K silicon in AF perspective. There are
         few updates w.r.t MBOX ACK interrupt and offsets in CN20k.

Patch #4 Added mbox implementation between NIC PF and AF for CN20K.

Patch #5 Added mbox communication support between AF and AF's VFs.

Patch #6 This patch adds support for MBOX communication between NIC PF and
         its VFs.
====================

Link: https://patch.msgid.link/1749639716-13868-1-git-send-email-sbhatta@marvell.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
alobakin pushed a commit that referenced this pull request Jul 25, 2025
…/kernel/git/kvmarm/kvmarm into HEAD

KVM/arm64 fixes for 6.16, take #6

- Fix use of u64_replace_bits() in adjusting the guest's view of
  MDCR_EL2.HPMN.
alobakin pushed a commit that referenced this pull request Aug 4, 2025
pert script tests fails with segmentation fault as below:

  92: perf script tests:
  --- start ---
  test child forked, pid 103769
  DB test
  [ perf record: Woken up 1 times to write data ]
  [ perf record: Captured and wrote 0.012 MB /tmp/perf-test-script.7rbftEpOzX/perf.data (9 samples) ]
  /usr/libexec/perf-core/tests/shell/script.sh: line 35:
  103780 Segmentation fault      (core dumped)
  perf script -i "${perfdatafile}" -s "${db_test}"
  --- Cleaning up ---
  ---- end(-1) ----
  92: perf script tests                                               : FAILED!

Backtrace pointed to :
	#0  0x0000000010247dd0 in maps.machine ()
	#1  0x00000000101d178c in db_export.sample ()
	#2  0x00000000103412c8 in python_process_event ()
	#3  0x000000001004eb28 in process_sample_event ()
	#4  0x000000001024fcd0 in machines.deliver_event ()
	#5  0x000000001025005c in perf_session.deliver_event ()
	#6  0x00000000102568b0 in __ordered_events__flush.part.0 ()
	#7  0x0000000010251618 in perf_session.process_events ()
	#8  0x0000000010053620 in cmd_script ()
	#9  0x00000000100b5a28 in run_builtin ()
	#10 0x00000000100b5f94 in handle_internal_command ()
	#11 0x0000000010011114 in main ()

Further investigation reveals that this occurs in the `perf script tests`,
because it uses `db_test.py` script. This script sets `perf_db_export_mode = True`.

With `perf_db_export_mode` enabled, if a sample originates from a hypervisor,
perf doesn't set maps for "[H]" sample in the code. Consequently, `al->maps` remains NULL
when `maps__machine(al->maps)` is called from `db_export__sample`.

As al->maps can be NULL in case of Hypervisor samples , use thread->maps
because even for Hypervisor sample, machine should exist.
If we don't have machine for some reason, return -1 to avoid segmentation fault.

Reported-by: Disha Goel <disgoel@linux.ibm.com>
Signed-off-by: Aditya Bodkhe <aditya.b1@linux.ibm.com>
Reviewed-by: Adrian Hunter <adrian.hunter@intel.com>
Tested-by: Disha Goel <disgoel@linux.ibm.com>
Link: https://lore.kernel.org/r/20250429065132.36839-1-adityab1@linux.ibm.com
Suggested-by: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
alobakin pushed a commit that referenced this pull request Aug 4, 2025
Without the change `perf `hangs up on charaster devices. On my system
it's enough to run system-wide sampler for a few seconds to get the
hangup:

    $ perf record -a -g --call-graph=dwarf
    $ perf report
    # hung

`strace` shows that hangup happens on reading on a character device
`/dev/dri/renderD128`

    $ strace -y -f -p 2780484
    strace: Process 2780484 attached
    pread64(101</dev/dri/renderD128>, strace: Process 2780484 detached

It's call trace descends into `elfutils`:

    $ gdb -p 2780484
    (gdb) bt
    #0  0x00007f5e508f04b7 in __libc_pread64 (fd=101, buf=0x7fff9df7edb0, count=0, offset=0)
        at ../sysdeps/unix/sysv/linux/pread64.c:25
    #1  0x00007f5e52b79515 in read_file () from /<<NIX>>/elfutils-0.192/lib/libelf.so.1
    #2  0x00007f5e52b25666 in libdw_open_elf () from /<<NIX>>/elfutils-0.192/lib/libdw.so.1
    #3  0x00007f5e52b25907 in __libdw_open_file () from /<<NIX>>/elfutils-0.192/lib/libdw.so.1
    #4  0x00007f5e52b120a9 in dwfl_report_elf@@ELFUTILS_0.156 ()
       from /<<NIX>>/elfutils-0.192/lib/libdw.so.1
    #5  0x000000000068bf20 in __report_module (al=al@entry=0x7fff9df80010, ip=ip@entry=139803237033216, ui=ui@entry=0x5369b5e0)
        at util/dso.h:537
    #6  0x000000000068c3d1 in report_module (ip=139803237033216, ui=0x5369b5e0) at util/unwind-libdw.c:114
    #7  frame_callback (state=0x535aef10, arg=0x5369b5e0) at util/unwind-libdw.c:242
    #8  0x00007f5e52b261d3 in dwfl_thread_getframes () from /<<NIX>>/elfutils-0.192/lib/libdw.so.1
    #9  0x00007f5e52b25bdb in get_one_thread_cb () from /<<NIX>>/elfutils-0.192/lib/libdw.so.1
    #10 0x00007f5e52b25faa in dwfl_getthreads () from /<<NIX>>/elfutils-0.192/lib/libdw.so.1
    #11 0x00007f5e52b26514 in dwfl_getthread_frames () from /<<NIX>>/elfutils-0.192/lib/libdw.so.1
    #12 0x000000000068c6ce in unwind__get_entries (cb=cb@entry=0x5d4620 <unwind_entry>, arg=arg@entry=0x10cd5fa0,
        thread=thread@entry=0x1076a290, data=data@entry=0x7fff9df80540, max_stack=max_stack@entry=127,
        best_effort=best_effort@entry=false) at util/thread.h:152
    #13 0x00000000005dae95 in thread__resolve_callchain_unwind (evsel=0x106006d0, thread=0x1076a290, cursor=0x10cd5fa0,
        sample=0x7fff9df80540, max_stack=127, symbols=true) at util/machine.c:2939
    #14 thread__resolve_callchain_unwind (thread=0x1076a290, cursor=0x10cd5fa0, evsel=0x106006d0, sample=0x7fff9df80540,
        max_stack=127, symbols=true) at util/machine.c:2920
    #15 __thread__resolve_callchain (thread=0x1076a290, cursor=0x10cd5fa0, evsel=0x106006d0, evsel@entry=0x7fff9df80440,
        sample=0x7fff9df80540, parent=parent@entry=0x7fff9df804a0, root_al=root_al@entry=0x7fff9df80440, max_stack=127, symbols=true)
        at util/machine.c:2970
    #16 0x00000000005d0cb2 in thread__resolve_callchain (thread=<optimized out>, cursor=<optimized out>, evsel=0x7fff9df80440,
        sample=<optimized out>, parent=0x7fff9df804a0, root_al=0x7fff9df80440, max_stack=127) at util/machine.h:198
    #17 sample__resolve_callchain (sample=<optimized out>, cursor=<optimized out>, parent=parent@entry=0x7fff9df804a0,
        evsel=evsel@entry=0x106006d0, al=al@entry=0x7fff9df80440, max_stack=max_stack@entry=127) at util/callchain.c:1127
    #18 0x0000000000617e08 in hist_entry_iter__add (iter=iter@entry=0x7fff9df80480, al=al@entry=0x7fff9df80440, max_stack_depth=127,
        arg=arg@entry=0x7fff9df81ae0) at util/hist.c:1255
    #19 0x000000000045d2d0 in process_sample_event (tool=0x7fff9df81ae0, event=<optimized out>, sample=0x7fff9df80540,
        evsel=0x106006d0, machine=<optimized out>) at builtin-report.c:334
    #20 0x00000000005e3bb1 in perf_session__deliver_event (session=0x105ff2c0, event=0x7f5c7d735ca0, tool=0x7fff9df81ae0,
        file_offset=2914716832, file_path=0x105ffbf0 "perf.data") at util/session.c:1367
    #21 0x00000000005e8d93 in do_flush (oe=0x105ffa50, show_progress=false) at util/ordered-events.c:245
    #22 __ordered_events__flush (oe=0x105ffa50, how=OE_FLUSH__ROUND, timestamp=<optimized out>) at util/ordered-events.c:324
    #23 0x00000000005e1f64 in perf_session__process_user_event (session=0x105ff2c0, event=0x7f5c7d752b18, file_offset=2914835224,
        file_path=0x105ffbf0 "perf.data") at util/session.c:1419
    #24 0x00000000005e47c7 in reader__read_event (rd=rd@entry=0x7fff9df81260, session=session@entry=0x105ff2c0,
    --Type <RET> for more, q to quit, c to continue without paging--
    quit
        prog=prog@entry=0x7fff9df81220) at util/session.c:2132
    #25 0x00000000005e4b37 in reader__process_events (rd=0x7fff9df81260, session=0x105ff2c0, prog=0x7fff9df81220)
        at util/session.c:2181
    #26 __perf_session__process_events (session=0x105ff2c0) at util/session.c:2226
    #27 perf_session__process_events (session=session@entry=0x105ff2c0) at util/session.c:2390
    #28 0x0000000000460add in __cmd_report (rep=0x7fff9df81ae0) at builtin-report.c:1076
    torvalds#29 cmd_report (argc=<optimized out>, argv=<optimized out>) at builtin-report.c:1827
    torvalds#30 0x00000000004c5a40 in run_builtin (p=p@entry=0xd8f7f8 <commands+312>, argc=argc@entry=1, argv=argv@entry=0x7fff9df844b0)
        at perf.c:351
    torvalds#31 0x00000000004c5d63 in handle_internal_command (argc=argc@entry=1, argv=argv@entry=0x7fff9df844b0) at perf.c:404
    torvalds#32 0x0000000000442de3 in run_argv (argcp=<synthetic pointer>, argv=<synthetic pointer>) at perf.c:448
    torvalds#33 main (argc=<optimized out>, argv=0x7fff9df844b0) at perf.c:556

The hangup happens because nothing in` perf` or `elfutils` checks if a
mapped file is easily readable.

The change conservatively skips all non-regular files.

Signed-off-by: Sergei Trofimovich <slyich@gmail.com>
Acked-by: Namhyung Kim <namhyung@kernel.org>
Link: https://lore.kernel.org/r/20250505174419.2814857-1-slyich@gmail.com
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
alobakin pushed a commit that referenced this pull request Aug 4, 2025
Symbolize stack traces by creating a live machine. Add this
functionality to dump_stack and switch dump_stack users to use
it. Switch TUI to use it. Add stack traces to the child test function
which can be useful to diagnose blocked code.

Example output:
```
$ perf test -vv PERF_RECORD_
...
  7: PERF_RECORD_* events & perf_sample fields:
  7: PERF_RECORD_* events & perf_sample fields                       : Running (1 active)
^C
Signal (2) while running tests.
Terminating tests with the same signal
Internal test harness failure. Completing any started tests:
:  7: PERF_RECORD_* events & perf_sample fields:

---- unexpected signal (2) ----
    #0 0x55788c6210a3 in child_test_sig_handler builtin-test.c:0
    #1 0x7fc12fe49df0 in __restore_rt libc_sigaction.c:0
    #2 0x7fc12fe99687 in __internal_syscall_cancel cancellation.c:64
    #3 0x7fc12fee5f7a in clock_nanosleep@GLIBC_2.2.5 clock_nanosleep.c:72
    #4 0x7fc12fef1393 in __nanosleep nanosleep.c:26
    #5 0x7fc12ff02d68 in __sleep sleep.c:55
    #6 0x55788c63196b in test__PERF_RECORD perf-record.c:0
    #7 0x55788c620fb0 in run_test_child builtin-test.c:0
    #8 0x55788c5bd18d in start_command run-command.c:127
    #9 0x55788c621ef3 in __cmd_test builtin-test.c:0
    #10 0x55788c6225bf in cmd_test ??:0
    #11 0x55788c5afbd0 in run_builtin perf.c:0
    #12 0x55788c5afeeb in handle_internal_command perf.c:0
    #13 0x55788c52b383 in main ??:0
    #14 0x7fc12fe33ca8 in __libc_start_call_main libc_start_call_main.h:74
    #15 0x7fc12fe33d65 in __libc_start_main@@GLIBC_2.34 libc-start.c:128
    #16 0x55788c52b9d1 in _start ??:0

---- unexpected signal (2) ----
    #0 0x55788c6210a3 in child_test_sig_handler builtin-test.c:0
    #1 0x7fc12fe49df0 in __restore_rt libc_sigaction.c:0
    #2 0x7fc12fea3a14 in pthread_sigmask@GLIBC_2.2.5 pthread_sigmask.c:45
    #3 0x7fc12fe49fd9 in __GI___sigprocmask sigprocmask.c:26
    #4 0x7fc12ff2601b in __longjmp_chk longjmp.c:36
    #5 0x55788c6210c0 in print_test_result.isra.0 builtin-test.c:0
    #6 0x7fc12fe49df0 in __restore_rt libc_sigaction.c:0
    #7 0x7fc12fe99687 in __internal_syscall_cancel cancellation.c:64
    #8 0x7fc12fee5f7a in clock_nanosleep@GLIBC_2.2.5 clock_nanosleep.c:72
    #9 0x7fc12fef1393 in __nanosleep nanosleep.c:26
    #10 0x7fc12ff02d68 in __sleep sleep.c:55
    #11 0x55788c63196b in test__PERF_RECORD perf-record.c:0
    #12 0x55788c620fb0 in run_test_child builtin-test.c:0
    #13 0x55788c5bd18d in start_command run-command.c:127
    #14 0x55788c621ef3 in __cmd_test builtin-test.c:0
    #15 0x55788c6225bf in cmd_test ??:0
    #16 0x55788c5afbd0 in run_builtin perf.c:0
    #17 0x55788c5afeeb in handle_internal_command perf.c:0
    #18 0x55788c52b383 in main ??:0
    #19 0x7fc12fe33ca8 in __libc_start_call_main libc_start_call_main.h:74
    #20 0x7fc12fe33d65 in __libc_start_main@@GLIBC_2.34 libc-start.c:128
    #21 0x55788c52b9d1 in _start ??:0
  7: PERF_RECORD_* events & perf_sample fields                       : Skip (permissions)
```

Signed-off-by: Ian Rogers <irogers@google.com>
Link: https://lore.kernel.org/r/20250624210500.2121303-1-irogers@google.com
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
alobakin pushed a commit that referenced this pull request Aug 4, 2025
Calling perf top with branch filters enabled on Intel CPU's
with branch counters logging (A.K.A LBR event logging [1]) support
results in a segfault.

$ perf top  -e '{cpu_core/cpu-cycles/,cpu_core/event=0xc6,umask=0x3,frontend=0x11,name=frontend_retired_dsb_miss/}' -j any,counter
...
Thread 27 "perf" received signal SIGSEGV, Segmentation fault.
[Switching to Thread 0x7fffafff76c0 (LWP 949003)]
perf_env__find_br_cntr_info (env=0xf66dc0 <perf_env>, nr=0x0, width=0x7fffafff62c0) at util/env.c:653
653			*width = env->cpu_pmu_caps ? env->br_cntr_width :
(gdb) bt
 #0  perf_env__find_br_cntr_info (env=0xf66dc0 <perf_env>, nr=0x0, width=0x7fffafff62c0) at util/env.c:653
 #1  0x00000000005b1599 in symbol__account_br_cntr (branch=0x7fffcc3db580, evsel=0xfea2d0, offset=12, br_cntr=8) at util/annotate.c:345
 #2  0x00000000005b17fb in symbol__account_cycles (addr=5658172, start=5658160, sym=0x7fffcc0ee420, cycles=539, evsel=0xfea2d0, br_cntr=8) at util/annotate.c:389
 #3  0x00000000005b1976 in addr_map_symbol__account_cycles (ams=0x7fffcd7b01d0, start=0x7fffcd7b02b0, cycles=539, evsel=0xfea2d0, br_cntr=8) at util/annotate.c:422
 #4  0x000000000068d57f in hist__account_cycles (bs=0x110d288, al=0x7fffafff6540, sample=0x7fffafff6760, nonany_branch_mode=false, total_cycles=0x0, evsel=0xfea2d0) at util/hist.c:2850
 #5  0x0000000000446216 in hist_iter__top_callback (iter=0x7fffafff6590, al=0x7fffafff6540, single=true, arg=0x7fffffff9e00) at builtin-top.c:737
 #6  0x0000000000689787 in hist_entry_iter__add (iter=0x7fffafff6590, al=0x7fffafff6540, max_stack_depth=127, arg=0x7fffffff9e00) at util/hist.c:1359
 #7  0x0000000000446710 in perf_event__process_sample (tool=0x7fffffff9e00, event=0x110d250, evsel=0xfea2d0, sample=0x7fffafff6760, machine=0x108c968) at builtin-top.c:845
 #8  0x0000000000447735 in deliver_event (qe=0x7fffffffa120, qevent=0x10fc200) at builtin-top.c:1211
 #9  0x000000000064ccae in do_flush (oe=0x7fffffffa120, show_progress=false) at util/ordered-events.c:245
 #10 0x000000000064d005 in __ordered_events__flush (oe=0x7fffffffa120, how=OE_FLUSH__TOP, timestamp=0) at util/ordered-events.c:324
 #11 0x000000000064d0ef in ordered_events__flush (oe=0x7fffffffa120, how=OE_FLUSH__TOP) at util/ordered-events.c:342
 #12 0x00000000004472a9 in process_thread (arg=0x7fffffff9e00) at builtin-top.c:1120
 #13 0x00007ffff6e7dba8 in start_thread (arg=<optimized out>) at pthread_create.c:448
 #14 0x00007ffff6f01b8c in __GI___clone3 () at ../sysdeps/unix/sysv/linux/x86_64/clone3.S:78

The cause is that perf_env__find_br_cntr_info tries to access a
null pointer pmu_caps in the perf_env struct. A similar issue exists
for homogeneous core systems which use the cpu_pmu_caps structure.

Fix this by populating cpu_pmu_caps and pmu_caps structures with
values from sysfs when calling perf top with branch stack sampling
enabled.

[1], LBR event logging introduced here:
https://lore.kernel.org/all/20231025201626.3000228-5-kan.liang@linux.intel.com/

Reviewed-by: Ian Rogers <irogers@google.com>
Signed-off-by: Thomas Falcon <thomas.falcon@intel.com>
Link: https://lore.kernel.org/r/20250612163659.1357950-2-thomas.falcon@intel.com
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
alobakin pushed a commit that referenced this pull request Sep 1, 2025
These iterations require the read lock, otherwise RCU
lockdep will splat:

=============================
WARNING: suspicious RCU usage
6.17.0-rc3-00014-g31419c045d64 #6 Tainted: G           O
-----------------------------
drivers/base/power/main.c:1333 RCU-list traversed in non-reader section!!

other info that might help us debug this:

rcu_scheduler_active = 2, debug_locks = 1
5 locks held by rtcwake/547:
 #0: 00000000643ab418 (sb_writers#6){.+.+}-{0:0}, at: file_start_write+0x2b/0x3a
 #1: 0000000067a0ca88 (&of->mutex#2){+.+.}-{4:4}, at: kernfs_fop_write_iter+0x181/0x24b
 #2: 00000000631eac40 (kn->active#3){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x191/0x24b
 #3: 00000000609a1308 (system_transition_mutex){+.+.}-{4:4}, at: pm_suspend+0xaf/0x30b
 #4: 0000000060c0fdb0 (device_links_srcu){.+.+}-{0:0}, at: device_links_read_lock+0x75/0x98

stack backtrace:
CPU: 0 UID: 0 PID: 547 Comm: rtcwake Tainted: G           O        6.17.0-rc3-00014-g31419c045d64 #6 VOLUNTARY
Tainted: [O]=OOT_MODULE
Stack:
 223721b3a80 6089eac6 00000001 00000001
 ffffff00 6089eac6 00000535 6086e528
 721b3ac0 6003c294 00000000 60031fc0
Call Trace:
 [<600407ed>] show_stack+0x10e/0x127
 [<6003c294>] dump_stack_lvl+0x77/0xc6
 [<6003c2fd>] dump_stack+0x1a/0x20
 [<600bc2f8>] lockdep_rcu_suspicious+0x116/0x13e
 [<603d8ea1>] dpm_async_suspend_superior+0x117/0x17e
 [<603d980f>] device_suspend+0x528/0x541
 [<603da24b>] dpm_suspend+0x1a2/0x267
 [<603da837>] dpm_suspend_start+0x5d/0x72
 [<600ca0c9>] suspend_devices_and_enter+0xab/0x736
 [...]

Add the fourth argument to the iteration to annotate
this and avoid the splat.

Fixes: 0679963 ("PM: sleep: Make async suspend handle suppliers like parents")
Fixes: ed18738 ("PM: sleep: Make async resume handle consumers like children")
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Link: https://patch.msgid.link/20250826134348.aba79f6e6299.I9ecf55da46ccf33778f2c018a82e1819d815b348@changeid
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
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