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@mpe mpe commented May 20, 2015

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ddstreet added 10 commits May 20, 2015 10:41
Export the of_get_ibm_chip_id() function.  This will be used by the
PowerNV NX-842 driver.

Signed-off-by: Dan Streetman <ddstreet@ieee.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Add the asm ICSWX and ICSWEPX opcodes.  Add definitions for the
Coprocessor Request structures needed to use the icswx calls to
coprocessors.  Add icswx() function to perform the ICSWX asm
using the provided Coprocessor Command Word value and
Coprocessor Request Block structure.

This is required for communication with the NX-842 coprocessor on
a PowerNV system.

Signed-off-by: Dan Streetman <ddstreet@ieee.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Add 842-format software compression and decompression functions.
Update the MAINTAINERS 842 section to include the new files.

The 842 compression function can compress any input data into the 842
compression format.  The 842 decompression function can decompress any
standard-format 842 compressed data - specifically, either a compressed
data buffer created by the 842 software compression function, or a
compressed data buffer created by the 842 hardware compressor (located
in PowerPC coprocessors).

The 842 compressed data format is explained in the header comments.

This is used in a later patch to provide a full software 842 compression
and decompression crypto interface.

Signed-off-by: Dan Streetman <ddstreet@ieee.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Change the crypto 842 compression alg to use the software 842 compression
and decompression library.  Add the crypto driver_name as "842-generic".
Remove the fallback to LZO compression.

Previously, this crypto compression alg attemped 842 compression using
PowerPC hardware, and fell back to LZO compression and decompression if
the 842 PowerPC hardware was unavailable or failed.  This should not
fall back to any other compression method, however; users of this crypto
compression alg can fallback if desired, and transparent fallback tricks
callers into thinking they are getting 842 compression when they actually
get LZO compression - the failure of the 842 hardware should not be
transparent to the caller.

The crypto compression alg for a hardware device also should not be located
in crypto/ so this is now a software-only implementation that uses the 842
software compression/decompression library.

Signed-off-by: Dan Streetman <ddstreet@ieee.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Move the entire NX-842 driver for the pSeries platform from the file
nx-842.c to nx-842-pseries.c.  This is required by later patches that
add NX-842 support for the PowerNV platform.

This patch does not alter the content of the pSeries NX-842 driver at
all, it only changes the filename.

Signed-off-by: Dan Streetman <ddstreet@ieee.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Add NX-842 frontend that allows using either the pSeries platform or
PowerNV platform driver (to be added by later patch) for the NX-842
hardware.  Update the MAINTAINERS file to include the new filenames.
Update Kconfig files to clarify titles and descriptions, and correct
dependencies.

Signed-off-by: Dan Streetman <ddstreet@ieee.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Add "constraints" for the NX-842 driver.  The constraints are used to
indicate what the current NX-842 platform driver is capable of.  The
constraints tell the NX-842 user what alignment, min and max length, and
length multiple each provided buffers should conform to.  These are
required because the 842 hardware requires buffers to meet specific
constraints that vary based on platform - for example, the pSeries
max length is much lower than the PowerNV max length.

Signed-off-by: Dan Streetman <ddstreet@ieee.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Add driver for NX-842 hardware on the PowerNV platform.

This allows the use of the 842 compression hardware coprocessor on
the PowerNV platform.

Signed-off-by: Dan Streetman <ddstreet@ieee.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Simplify the pSeries NX-842 driver: do not expect incoming buffers to be
exactly page-sized; do not break up input buffers to compress smaller
blocks; do not use any internal headers in the compressed data blocks;
remove the software decompression implementation; implement the pSeries
nx842_constraints.

This changes the pSeries NX-842 driver to perform constraints-based
compression so that it only needs to compress one entire input block at a
time.  This removes the need for it to split input data blocks into
multiple compressed data sections in the output buffer, and removes the
need for any extra header info in the compressed data; all that is moved
(in a later patch) into the main crypto 842 driver.  Additionally, the
842 software decompression implementation is no longer needed here, as
the crypto 842 driver will use the generic software 842 decompression
function as a fallback if any hardware 842 driver fails.

Signed-off-by: Dan Streetman <ddstreet@ieee.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Add crypto compression alg for 842 hardware compression and decompression,
using the alg name "842" and driver_name "842-nx".

This uses only the PowerPC coprocessor hardware for 842 compression.  It
also uses the hardware for decompression, but if the hardware fails it will
fall back to the 842 software decompression library, so that decompression
never fails (for valid 842 compressed buffers).  A header must be used in
most cases, due to the hardware's restrictions on the buffers being
specifically aligned and sized.

Due to the header this driver adds, compressed buffers it creates cannot be
directly passed to the 842 software library for decompression.  However,
compressed buffers created by the software 842 library can be passed to
this driver for hardware 842 decompression (with the exception of buffers
containing the "short data" template, as lib/842/842.h explains).

Signed-off-by: Dan Streetman <ddstreet@ieee.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
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mpe commented May 21, 2015

Kisskb: OK

@mpe mpe added the kisskb label May 21, 2015
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mpe commented May 21, 2015

Buildbot: OK

@mpe mpe added buildbot and removed OK labels May 21, 2015
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mpe commented May 22, 2015

Selftests: OK

mpe pushed a commit that referenced this pull request Sep 3, 2015
Nikolay has reported a hang when a memcg reclaim got stuck with the
following backtrace:

PID: 18308  TASK: ffff883d7c9b0a30  CPU: 1   COMMAND: "rsync"
  #0 __schedule at ffffffff815ab152
  #1 schedule at ffffffff815ab76e
  #2 schedule_timeout at ffffffff815ae5e5
  #3 io_schedule_timeout at ffffffff815aad6a
  #4 bit_wait_io at ffffffff815abfc6
  #5 __wait_on_bit at ffffffff815abda5
  #6 wait_on_page_bit at ffffffff8111fd4f
  #7 shrink_page_list at ffffffff81135445
  #8 shrink_inactive_list at ffffffff81135845
  #9 shrink_lruvec at ffffffff81135ead
 #10 shrink_zone at ffffffff811360c3
 torvalds#11 shrink_zones at ffffffff81136eff
 torvalds#12 do_try_to_free_pages at ffffffff8113712f
 torvalds#13 try_to_free_mem_cgroup_pages at ffffffff811372be
 torvalds#14 try_charge at ffffffff81189423
 torvalds#15 mem_cgroup_try_charge at ffffffff8118c6f5
 torvalds#16 __add_to_page_cache_locked at ffffffff8112137d
 torvalds#17 add_to_page_cache_lru at ffffffff81121618
 torvalds#18 pagecache_get_page at ffffffff8112170b
 torvalds#19 grow_dev_page at ffffffff811c8297
 torvalds#20 __getblk_slow at ffffffff811c91d6
 torvalds#21 __getblk_gfp at ffffffff811c92c1
 torvalds#22 ext4_ext_grow_indepth at ffffffff8124565c
 torvalds#23 ext4_ext_create_new_leaf at ffffffff81246ca8
 torvalds#24 ext4_ext_insert_extent at ffffffff81246f09
 torvalds#25 ext4_ext_map_blocks at ffffffff8124a848
 torvalds#26 ext4_map_blocks at ffffffff8121a5b7
 torvalds#27 mpage_map_one_extent at ffffffff8121b1fa
 torvalds#28 mpage_map_and_submit_extent at ffffffff8121f07b
 torvalds#29 ext4_writepages at ffffffff8121f6d5
 torvalds#30 do_writepages at ffffffff8112c490
 torvalds#31 __filemap_fdatawrite_range at ffffffff81120199
 torvalds#32 filemap_flush at ffffffff8112041c
 torvalds#33 ext4_alloc_da_blocks at ffffffff81219da1
 torvalds#34 ext4_rename at ffffffff81229b91
 torvalds#35 ext4_rename2 at ffffffff81229e32
 torvalds#36 vfs_rename at ffffffff811a08a5
 torvalds#37 SYSC_renameat2 at ffffffff811a3ffc
 torvalds#38 sys_renameat2 at ffffffff811a408e
 torvalds#39 sys_rename at ffffffff8119e51e
 torvalds#40 system_call_fastpath at ffffffff815afa89

Dave Chinner has properly pointed out that this is a deadlock in the
reclaim code because ext4 doesn't submit pages which are marked by
PG_writeback right away.

The heuristic was introduced by commit e62e384 ("memcg: prevent OOM
with too many dirty pages") and it was applied only when may_enter_fs
was specified.  The code has been changed by c3b94f4 ("memcg:
further prevent OOM with too many dirty pages") which has removed the
__GFP_FS restriction with a reasoning that we do not get into the fs
code.  But this is not sufficient apparently because the fs doesn't
necessarily submit pages marked PG_writeback for IO right away.

ext4_bio_write_page calls io_submit_add_bh but that doesn't necessarily
submit the bio.  Instead it tries to map more pages into the bio and
mpage_map_one_extent might trigger memcg charge which might end up
waiting on a page which is marked PG_writeback but hasn't been submitted
yet so we would end up waiting for something that never finishes.

Fix this issue by replacing __GFP_IO by may_enter_fs check (for case 2)
before we go to wait on the writeback.  The page fault path, which is
the only path that triggers memcg oom killer since 3.12, shouldn't
require GFP_NOFS and so we shouldn't reintroduce the premature OOM
killer issue which was originally addressed by the heuristic.

As per David Chinner the xfs is doing similar thing since 2.6.15 already
so ext4 is not the only affected filesystem.  Moreover he notes:

: For example: IO completion might require unwritten extent conversion
: which executes filesystem transactions and GFP_NOFS allocations. The
: writeback flag on the pages can not be cleared until unwritten
: extent conversion completes. Hence memory reclaim cannot wait on
: page writeback to complete in GFP_NOFS context because it is not
: safe to do so, memcg reclaim or otherwise.

Cc: stable@vger.kernel.org # 3.9+
[tytso@mit.edu: corrected the control flow]
Fixes: c3b94f4 ("memcg: further prevent OOM with too many dirty pages")
Reported-by: Nikolay Borisov <kernel@kyup.com>
Signed-off-by: Michal Hocko <mhocko@suse.cz>
Signed-off-by: Hugh Dickins <hughd@google.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
mpe pushed a commit that referenced this pull request Sep 3, 2015
It turns out that a PV domU also requires the "Xen PV" APIC
driver. Otherwise, the flat driver is used and we get stuck in busy
loops that never exit, such as in this stack trace:

(gdb) target remote localhost:9999
Remote debugging using localhost:9999
__xapic_wait_icr_idle () at ./arch/x86/include/asm/ipi.h:56
56              while (native_apic_mem_read(APIC_ICR) & APIC_ICR_BUSY)
(gdb) bt
 #0  __xapic_wait_icr_idle () at ./arch/x86/include/asm/ipi.h:56
 #1  __default_send_IPI_shortcut (shortcut=<optimized out>,
dest=<optimized out>, vector=<optimized out>) at
./arch/x86/include/asm/ipi.h:75
 #2  apic_send_IPI_self (vector=246) at arch/x86/kernel/apic/probe_64.c:54
 #3  0xffffffff81011336 in arch_irq_work_raise () at
arch/x86/kernel/irq_work.c:47
 #4  0xffffffff8114990c in irq_work_queue (work=0xffff88000fc0e400) at
kernel/irq_work.c:100
 #5  0xffffffff8110c29d in wake_up_klogd () at kernel/printk/printk.c:2633
 #6  0xffffffff8110ca60 in vprintk_emit (facility=0, level=<optimized
out>, dict=0x0 <irq_stack_union>, dictlen=<optimized out>,
fmt=<optimized out>, args=<optimized out>)
    at kernel/printk/printk.c:1778
 #7  0xffffffff816010c8 in printk (fmt=<optimized out>) at
kernel/printk/printk.c:1868
 #8  0xffffffffc00013ea in ?? ()
 #9  0x0000000000000000 in ?? ()

Mailing-list-thread: https://lkml.org/lkml/2015/8/4/755
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: David Vrabel <david.vrabel@citrix.com>
mpe pushed a commit that referenced this pull request Sep 3, 2015
A recent change to the cpu_cooling code introduced a AB-BA deadlock
scenario between the cpufreq_policy_notifier_list rwsem and the
cooling_cpufreq_lock.  This is caused by cooling_cpufreq_lock being held
before the registration/removal of the notifier block (an operation
which takes the rwsem), and the notifier code itself which takes the
locks in the reverse order:

======================================================
[ INFO: possible circular locking dependency detected ]
3.18.0+ #1453 Not tainted
-------------------------------------------------------
rc.local/770 is trying to acquire lock:
 (cooling_cpufreq_lock){+.+.+.}, at: [<c04abfc4>] cpufreq_thermal_notifier+0x34/0xfc

but task is already holding lock:
 ((cpufreq_policy_notifier_list).rwsem){++++.+}, at: [<c0042f04>]  __blocking_notifier_call_chain+0x34/0x68

which lock already depends on the new lock.

the existing dependency chain (in reverse order) is:

-> #1 ((cpufreq_policy_notifier_list).rwsem){++++.+}:
       [<c06bc3b0>] down_write+0x44/0x9c
       [<c0043444>] blocking_notifier_chain_register+0x28/0xd8
       [<c04ad610>] cpufreq_register_notifier+0x68/0x90
       [<c04abe4c>] __cpufreq_cooling_register.part.1+0x120/0x180
       [<c04abf44>] __cpufreq_cooling_register+0x98/0xa4
       [<c04abf8c>] cpufreq_cooling_register+0x18/0x1c
       [<bf0046f8>] imx_thermal_probe+0x1c0/0x470 [imx_thermal]
       [<c037cef8>] platform_drv_probe+0x50/0xac
       [<c037b710>] driver_probe_device+0x114/0x234
       [<c037b8cc>] __driver_attach+0x9c/0xa0
       [<c0379d68>] bus_for_each_dev+0x5c/0x90
       [<c037b204>] driver_attach+0x24/0x28
       [<c037ae7c>] bus_add_driver+0xe0/0x1d8
       [<c037c0cc>] driver_register+0x80/0xfc
       [<c037cd80>] __platform_driver_register+0x50/0x64
       [<bf007018>] 0xbf007018
       [<c0008a5c>] do_one_initcall+0x88/0x1d8
       [<c0095da4>] load_module+0x1768/0x1ef8
       [<c0096614>] SyS_init_module+0xe0/0xf4
       [<c000ec00>] ret_fast_syscall+0x0/0x48

-> #0 (cooling_cpufreq_lock){+.+.+.}:
       [<c00619f8>] lock_acquire+0xb0/0x124
       [<c06ba3b4>] mutex_lock_nested+0x5c/0x3d8
       [<c04abfc4>] cpufreq_thermal_notifier+0x34/0xfc
       [<c0042bf4>] notifier_call_chain+0x4c/0x8c
       [<c0042f20>] __blocking_notifier_call_chain+0x50/0x68
       [<c0042f58>] blocking_notifier_call_chain+0x20/0x28
       [<c04ae62c>] cpufreq_set_policy+0x7c/0x1d0
       [<c04af3cc>] store_scaling_governor+0x74/0x9c
       [<c04ad418>] store+0x90/0xc0
       [<c0175384>] sysfs_kf_write+0x54/0x58
       [<c01746b4>] kernfs_fop_write+0xdc/0x190
       [<c010dcc0>] vfs_write+0xac/0x1b4
       [<c010dfec>] SyS_write+0x44/0x90
       [<c000ec00>] ret_fast_syscall+0x0/0x48

other info that might help us debug this:

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock((cpufreq_policy_notifier_list).rwsem);
                               lock(cooling_cpufreq_lock);
                               lock((cpufreq_policy_notifier_list).rwsem);
  lock(cooling_cpufreq_lock);

 *** DEADLOCK ***

7 locks held by rc.local/770:
 #0:  (sb_writers#6){.+.+.+}, at: [<c010dda0>] vfs_write+0x18c/0x1b4
 #1:  (&of->mutex){+.+.+.}, at: [<c0174678>] kernfs_fop_write+0xa0/0x190
 #2:  (s_active#52){.+.+.+}, at: [<c0174680>] kernfs_fop_write+0xa8/0x190
 #3:  (cpu_hotplug.lock){++++++}, at: [<c0026a60>] get_online_cpus+0x34/0x90
 #4:  (cpufreq_rwsem){.+.+.+}, at: [<c04ad3e0>] store+0x58/0xc0
 #5:  (&policy->rwsem){+.+.+.}, at: [<c04ad3f8>] store+0x70/0xc0
 #6:  ((cpufreq_policy_notifier_list).rwsem){++++.+}, at: [<c0042f04>] __blocking_notifier_call_chain+0x34/0x68

stack backtrace:
CPU: 0 PID: 770 Comm: rc.local Not tainted 3.18.0+ #1453
Hardware name: Freescale i.MX6 Quad/DualLite (Device Tree)
Backtrace:
[<c00121c8>] (dump_backtrace) from [<c0012360>] (show_stack+0x18/0x1c)
 r6:c0b85a80 r5:c0b75630 r4:00000000 r3:00000000
[<c0012348>] (show_stack) from [<c06b6c48>] (dump_stack+0x7c/0x98)
[<c06b6bcc>] (dump_stack) from [<c06b42a4>] (print_circular_bug+0x28c/0x2d8)
 r4:c0b85a80 r3:d0071d40
[<c06b4018>] (print_circular_bug) from [<c00613b0>] (__lock_acquire+0x1acc/0x1bb0)
 r10:c0b50660 r8:c09e6d80 r7:d0071d40 r6:c11d0f0c r5:00000007 r4:d0072240
[<c005f8e4>] (__lock_acquire) from [<c00619f8>] (lock_acquire+0xb0/0x124)
 r10:00000000 r9:c04abfc4 r8:00000000 r7:00000000 r6:00000000 r5:c0a06f0c
 r4:00000000
[<c0061948>] (lock_acquire) from [<c06ba3b4>] (mutex_lock_nested+0x5c/0x3d8)
 r10:ec853800 r9:c0a06ed4 r8:d0071d40 r7:c0a06ed4 r6:c11d0f0c r5:00000000
 r4:c04abfc4
[<c06ba358>] (mutex_lock_nested) from [<c04abfc4>] (cpufreq_thermal_notifier+0x34/0xfc)
 r10:ec853800 r9:ec85380c r8:d00d7d3c r7:c0a06ed4 r6:d00d7d3c r5:00000000
 r4:fffffffe
[<c04abf90>] (cpufreq_thermal_notifier) from [<c0042bf4>] (notifier_call_chain+0x4c/0x8c)
 r7:00000000 r6:00000000 r5:00000000 r4:fffffffe
[<c0042ba8>] (notifier_call_chain) from [<c0042f20>] (__blocking_notifier_call_chain+0x50/0x68)
 r8:c0a072a4 r7:00000000 r6:d00d7d3c r5:ffffffff r4:c0a06fc8 r3:ffffffff
[<c0042ed0>] (__blocking_notifier_call_chain) from [<c0042f58>] (blocking_notifier_call_chain+0x20/0x28)
 r7:ec98b540 r6:c13ebc80 r5:ed76e600 r4:d00d7d3c
[<c0042f38>] (blocking_notifier_call_chain) from [<c04ae62c>] (cpufreq_set_policy+0x7c/0x1d0)
[<c04ae5b0>] (cpufreq_set_policy) from [<c04af3cc>] (store_scaling_governor+0x74/0x9c)
 r7:ec98b540 r6:0000000c r5:ec98b540 r4:ed76e600
[<c04af358>] (store_scaling_governor) from [<c04ad418>] (store+0x90/0xc0)
 r6:0000000c r5:ed76e6d4 r4:ed76e600
[<c04ad388>] (store) from [<c0175384>] (sysfs_kf_write+0x54/0x58)
 r8:0000000c r7:d00d7f78 r6:ec98b540 r5:0000000c r4:ec853800 r3:0000000c
[<c0175330>] (sysfs_kf_write) from [<c01746b4>] (kernfs_fop_write+0xdc/0x190)
 r6:ec98b540 r5:00000000 r4:00000000 r3:c0175330
[<c01745d8>] (kernfs_fop_write) from [<c010dcc0>] (vfs_write+0xac/0x1b4)
 r10:0162aa70 r9:d00d6000 r8:0000000c r7:d00d7f78 r6:0162aa70 r5:0000000c
 r4:eccde500
[<c010dc14>] (vfs_write) from [<c010dfec>] (SyS_write+0x44/0x90)
 r10:0162aa70 r8:0000000c r7:eccde500 r6:eccde500 r5:00000000 r4:00000000
[<c010dfa8>] (SyS_write) from [<c000ec00>] (ret_fast_syscall+0x0/0x48)
 r10:00000000 r8:c000edc4 r7:00000004 r6:000216cc r5:0000000c r4:0162aa70

Solve this by moving to finer grained locking - use one mutex to protect
the cpufreq_dev_list as a whole, and a separate lock to ensure correct
ordering of cpufreq notifier registration and removal.

cooling_list_lock is taken within cooling_cpufreq_lock on
(un)registration to preserve the behavior of the code, i.e. to
atomically add/remove to the list and (un)register the notifier.

Fixes: 2dcd851 ("thermal: cpu_cooling: Update always cpufreq policy with
Reviewed-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Eduardo Valentin <edubezval@gmail.com>
mpe pushed a commit that referenced this pull request Sep 3, 2015
The EPOW interrupt handler uses rtas_get_sensor(), which in turn
uses rtas_busy_delay() to wait for RTAS becoming ready in case it
is necessary. But rtas_busy_delay() is annotated with might_sleep()
and thus may not be used by interrupts handlers like the EPOW handler!
This leads to the following BUG when CONFIG_DEBUG_ATOMIC_SLEEP is
enabled:

 BUG: sleeping function called from invalid context at arch/powerpc/kernel/rtas.c:496
 in_atomic(): 1, irqs_disabled(): 1, pid: 0, name: swapper/1
 CPU: 1 PID: 0 Comm: swapper/1 Not tainted 4.2.0-rc2-thuth #6
 Call Trace:
 [c00000007ffe7b90] [c000000000807670] dump_stack+0xa0/0xdc (unreliable)
 [c00000007ffe7bc0] [c0000000000e1f14] ___might_sleep+0x134/0x180
 [c00000007ffe7c20] [c00000000002aec0] rtas_busy_delay+0x30/0xd0
 [c00000007ffe7c50] [c00000000002bde4] rtas_get_sensor+0x74/0xe0
 [c00000007ffe7ce0] [c000000000083264] ras_epow_interrupt+0x44/0x450
 [c00000007ffe7d90] [c000000000120260] handle_irq_event_percpu+0xa0/0x300
 [c00000007ffe7e70] [c000000000120524] handle_irq_event+0x64/0xc0
 [c00000007ffe7eb0] [c000000000124dbc] handle_fasteoi_irq+0xec/0x260
 [c00000007ffe7ef0] [c00000000011f4f0] generic_handle_irq+0x50/0x80
 [c00000007ffe7f20] [c000000000010f3c] __do_irq+0x8c/0x200
 [c00000007ffe7f90] [c0000000000236cc] call_do_irq+0x14/0x24
 [c00000007e6f39e0] [c000000000011144] do_IRQ+0x94/0x110
 [c00000007e6f3a30] [c000000000002594] hardware_interrupt_common+0x114/0x180

Fix this issue by introducing a new rtas_get_sensor_fast() function
that does not use rtas_busy_delay() - and thus can only be used for
sensors that do not cause a BUSY condition - known as "fast" sensors.

The EPOW sensor is defined to be "fast" in sPAPR - mpe.

Fixes: 587f83e ("powerpc/pseries: Use rtas_get_sensor in RAS code")
Signed-off-by: Thomas Huth <thuth@redhat.com>
Reviewed-by: Nathan Fontenot <nfont@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
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mpe commented Sep 3, 2015

Merged via crypto as ed70b47.

@mpe mpe closed this Sep 3, 2015
@mpe mpe deleted the review/nx branch September 3, 2015 12:48
mpe pushed a commit that referenced this pull request Sep 9, 2015
Not all gpio banks are necessarily enabled, in the current code this can
lead to null pointer dereferences.

[   51.130000] Unable to handle kernel NULL pointer dereference at virtual address 00000058
[   51.130000] pgd = dee04000
[   51.130000] [00000058] *pgd=3f66d831, *pte=00000000, *ppte=00000000
[   51.140000] Internal error: Oops: 17 [#1] ARM
[   51.140000] Modules linked in:
[   51.140000] CPU: 0 PID: 1664 Comm: cat Not tainted 4.1.1+ #6
[   51.140000] Hardware name: Atmel SAMA5
[   51.140000] task: df6dd880 ti: dec60000 task.ti: dec60000
[   51.140000] PC is at at91_pinconf_get+0xb4/0x200
[   51.140000] LR is at at91_pinconf_get+0xb4/0x200
[   51.140000] pc : [<c01e71a0>]    lr : [<c01e71a0>]    psr: 600f0013
sp : dec61e48  ip : 600f0013  fp : df522538
[   51.140000] r10: df52250c  r9 : 00000058  r8 : 00000068
[   51.140000] r7 : 00000000  r6 : df53c910  r5 : 00000000  r4 : dec61e7c
[   51.140000] r3 : 00000000  r2 : c06746d4  r1 : 00000000  r0 : 00000003
[   51.140000] Flags: nZCv  IRQs on  FIQs on  Mode SVC_32  ISA ARM  Segment user
[   51.140000] Control: 10c53c7d  Table: 3ee04059  DAC: 00000015
[   51.140000] Process cat (pid: 1664, stack limit = 0xdec60208)
[   51.140000] Stack: (0xdec61e48 to 0xdec62000)
[   51.140000] 1e40:                   00000358 00000000 df522500 ded15f80 c05a9d08 ded15f80
[   51.140000] 1e60: 0000048c 00000061 df522500 ded15f80 c05a9d08 c01e7304 ded15f80 00000000
[   51.140000] 1e80: c01e6008 00000060 0000048c c01e6034 c01e5f6c ded15f80 dec61ec 00000000
[   51.140000] 1ea0: 00020000 ded6f280 dec61f80 00000001 00000001 c00ae0b8 b6e80000 ded15fb0
[   51.140000] 1ec0: 00000000 00000000 df4bc974 00000055 00000800 ded6f280 b6e80000 ded6f280
[   51.140000] 1ee0: ded6f280 00020000 b6e80000 00000000 00020000 c0090dec c0671e1c dec61fb0
[   51.140000] 1f00: b6f8b510 00000001 00004201 c000924c 00000000 00000003 00000003 00000000
[   51.140000] 1f20: df4bc940 00022000 00000022 c066e188 b6e7f000 c00836f4 000b6e7f ded6f280
[   51.140000] 1f40: ded6f280 b6e80000 dec61f80 ded6f280 00020000 c0091508 00000000 00000003
[   51.140000] 1f60: 00022000 00000000 00000000 ded6f280 ded6f280 00020000 b6e80000 c0091d9c
[   51.140000] 1f80: 00000000 00000000 ffffffff 00020000 00020000 b6e80000 00000003 c000f124
[   51.140000] 1fa0: dec60000 c000efa0 00020000 00020000 00000003 b6e80000 00020000 000271c4
[   51.140000] 1fc0: 00020000 00020000 b6e80000 00000003 7fffe000 00000000 00000000 00020000
[   51.140000] 1fe0: 00000000 bef50b64 00013835 b6f29c76 400f0030 00000003 00000000 00000000
[   51.140000] [<c01e71a0>] (at91_pinconf_get) from [<c01e7304>] (at91_pinconf_dbg_show+0x18/0x2c0)
[   51.140000] [<c01e7304>] (at91_pinconf_dbg_show) from [<c01e6034>] (pinconf_pins_show+0xc8/0xf8)
[   51.140000] [<c01e6034>] (pinconf_pins_show) from [<c00ae0b8>] (seq_read+0x1a0/0x464)
[   51.140000] [<c00ae0b8>] (seq_read) from [<c0090dec>] (__vfs_read+0x20/0xd0)
[   51.140000] [<c0090dec>] (__vfs_read) from [<c0091508>] (vfs_read+0x7c/0x108)
[   51.140000] [<c0091508>] (vfs_read) from [<c0091d9c>] (SyS_read+0x40/0x94)
[   51.140000] [<c0091d9c>] (SyS_read) from [<c000efa0>] (ret_fast_syscall+0x0/0x3c)
[   51.140000] Code: eb010ec2 e30a0d08 e34c005a eb0ae5a7 (e5993000)
[   51.150000] ---[ end trace fb3c370da3ea4794 ]---

Fixes: a0b957f ("pinctrl: at91: allow to have disabled gpio bank")
Cc: stable@vger.kernel.org # 3.18
Signed-off-by: David Dueck <davidcdueck@googlemail.com>
Acked-by: Ludovic Desroches <ludovic.desroches@atmel.com>
Acked-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Cc: Boris Brezillon <boris.brezillon@free-electrons.com>
Cc: Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
mpe pushed a commit that referenced this pull request Sep 9, 2015
PID: 614    TASK: ffff882a739da580  CPU: 3   COMMAND: "ocfs2dc"
  #0 [ffff882ecc3759b0] machine_kexec at ffffffff8103b35d
  #1 [ffff882ecc375a20] crash_kexec at ffffffff810b95b5
  #2 [ffff882ecc375af0] oops_end at ffffffff815091d8
  #3 [ffff882ecc375b20] die at ffffffff8101868b
  #4 [ffff882ecc375b50] do_trap at ffffffff81508bb0
  #5 [ffff882ecc375ba0] do_invalid_op at ffffffff810165e5
  #6 [ffff882ecc375c40] invalid_op at ffffffff815116fb
     [exception RIP: ocfs2_ci_checkpointed+208]
     RIP: ffffffffa0a7e940  RSP: ffff882ecc375cf0  RFLAGS: 00010002
     RAX: 0000000000000001  RBX: 000000000000654b  RCX: ffff8812dc83f1f8
     RDX: 00000000000017d9  RSI: ffff8812dc83f1f8  RDI: ffffffffa0b2c318
     RBP: ffff882ecc375d20   R8: ffff882ef6ecfa60   R9: ffff88301f272200
     R10: 0000000000000000  R11: 0000000000000000  R12: ffffffffffffffff
     R13: ffff8812dc83f4f0  R14: 0000000000000000  R15: ffff8812dc83f1f8
     ORIG_RAX: ffffffffffffffff  CS: 0010  SS: 0018
  #7 [ffff882ecc375d28] ocfs2_check_meta_downconvert at ffffffffa0a7edbd [ocfs2]
  #8 [ffff882ecc375d38] ocfs2_unblock_lock at ffffffffa0a84af8 [ocfs2]
  #9 [ffff882ecc375dc8] ocfs2_process_blocked_lock at ffffffffa0a85285 [ocfs2]
#10 [ffff882ecc375e18] ocfs2_downconvert_thread_do_work at ffffffffa0a85445 [ocfs2]
torvalds#11 [ffff882ecc375e68] ocfs2_downconvert_thread at ffffffffa0a854de [ocfs2]
torvalds#12 [ffff882ecc375ee8] kthread at ffffffff81090da7
torvalds#13 [ffff882ecc375f48] kernel_thread_helper at ffffffff81511884
assert is tripped because the tran is not checkpointed and the lock level is PR.

Some time ago, chmod command had been executed. As result, the following call
chain left the inode cluster lock in PR state, latter on causing the assert.
system_call_fastpath
  -> my_chmod
   -> sys_chmod
    -> sys_fchmodat
     -> notify_change
      -> ocfs2_setattr
       -> posix_acl_chmod
        -> ocfs2_iop_set_acl
         -> ocfs2_set_acl
          -> ocfs2_acl_set_mode
Here is how.
1119 int ocfs2_setattr(struct dentry *dentry, struct iattr *attr)
1120 {
1247         ocfs2_inode_unlock(inode, 1); <<< WRONG thing to do.
..
1258         if (!status && attr->ia_valid & ATTR_MODE) {
1259                 status =  posix_acl_chmod(inode, inode->i_mode);

519 posix_acl_chmod(struct inode *inode, umode_t mode)
520 {
..
539         ret = inode->i_op->set_acl(inode, acl, ACL_TYPE_ACCESS);

287 int ocfs2_iop_set_acl(struct inode *inode, struct posix_acl *acl, ...
288 {
289         return ocfs2_set_acl(NULL, inode, NULL, type, acl, NULL, NULL);

224 int ocfs2_set_acl(handle_t *handle,
225                          struct inode *inode, ...
231 {
..
252                                 ret = ocfs2_acl_set_mode(inode, di_bh,
253                                                          handle, mode);

168 static int ocfs2_acl_set_mode(struct inode *inode, struct buffer_head ...
170 {
183         if (handle == NULL) {
                    >>> BUG: inode lock not held in ex at this point <<<
184                 handle = ocfs2_start_trans(OCFS2_SB(inode->i_sb),
185                                            OCFS2_INODE_UPDATE_CREDITS);

ocfs2_setattr.torvalds#1247 we unlock and at torvalds#1259 call posix_acl_chmod. When we reach
ocfs2_acl_set_mode.torvalds#181 and do trans, the inode cluster lock is not held in EX
mode (it should be). How this could have happended?

We are the lock master, were holding lock EX and have released it in
ocfs2_setattr.torvalds#1247.  Note that there are no holders of this lock at
this point.  Another node needs the lock in PR, and we downconvert from
EX to PR.  So the inode lock is PR when do the trans in
ocfs2_acl_set_mode.torvalds#184.  The trans stays in core (not flushed to disc).
Now another node want the lock in EX, downconvert thread gets kicked
(the one that tripped assert abovt), finds an unflushed trans but the
lock is not EX (it is PR).  If the lock was at EX, it would have flushed
the trans ocfs2_ci_checkpointed -> ocfs2_start_checkpoint before
downconverting (to NULL) for the request.

ocfs2_setattr must not drop inode lock ex in this code path.  If it
does, takes it again before the trans, say in ocfs2_set_acl, another
cluster node can get in between, execute another setattr, overwriting
the one in progress on this node, resulting in a mode acl size combo
that is a mix of the two.

Orabug: 20189959
Signed-off-by: Tariq Saeed <tariq.x.saeed@oracle.com>
Reviewed-by: Mark Fasheh <mfasheh@suse.de>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Joseph Qi <joseph.qi@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
mpe pushed a commit that referenced this pull request Feb 7, 2019
Ido Schimmel says:

====================
mlxsw: Various fixes

This patchset contains small fixes in mlxsw and one fix in the bridge
driver.

Patches #1-#4 perform small adjustments in PCI and FID code following
recent tests that were performed on the Spectrum-2 ASIC.

Patch #5 fixes the bridge driver to mark FDB entries that were added by
user as such. Otherwise, these entries will be ignored by underlying
switch drivers.

Patch #6 fixes a long standing issue in mlxsw where the driver
incorrectly programmed static FDB entries as both static and sticky.

Patches #7-#8 add test cases for above mentioned bugs.

Please consider patches #1, #2 and #4 for stable.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>
mpe pushed a commit that referenced this pull request Feb 7, 2019
When option CONFIG_KASAN is enabled toghether with ftrace, function
ftrace_graph_caller() gets in to a recursion, via functions
kasan_check_read() and kasan_check_write().

 Breakpoint 2, ftrace_graph_caller () at ../arch/arm64/kernel/entry-ftrace.S:179
 179             mcount_get_pc             x0    //     function's pc
 (gdb) bt
 #0  ftrace_graph_caller () at ../arch/arm64/kernel/entry-ftrace.S:179
 #1  0xffffff90101406c8 in ftrace_caller () at ../arch/arm64/kernel/entry-ftrace.S:151
 #2  0xffffff90106fd084 in kasan_check_write (p=0xffffffc06c170878, size=4) at ../mm/kasan/common.c:105
 #3  0xffffff90104a2464 in atomic_add_return (v=<optimized out>, i=<optimized out>) at ./include/generated/atomic-instrumented.h:71
 #4  atomic_inc_return (v=<optimized out>) at ./include/generated/atomic-fallback.h:284
 #5  trace_graph_entry (trace=0xffffffc03f5ff380) at ../kernel/trace/trace_functions_graph.c:441
 #6  0xffffff9010481774 in trace_graph_entry_watchdog (trace=<optimized out>) at ../kernel/trace/trace_selftest.c:741
 #7  0xffffff90104a185c in function_graph_enter (ret=<optimized out>, func=<optimized out>, frame_pointer=18446743799894897728, retp=<optimized out>) at ../kernel/trace/trace_functions_graph.c:196
 #8  0xffffff9010140628 in prepare_ftrace_return (self_addr=18446743592948977792, parent=0xffffffc03f5ff418, frame_pointer=18446743799894897728) at ../arch/arm64/kernel/ftrace.c:231
 #9  0xffffff90101406f4 in ftrace_graph_caller () at ../arch/arm64/kernel/entry-ftrace.S:182
 Backtrace stopped: previous frame identical to this frame (corrupt stack?)
 (gdb)

Rework so that the kasan implementation isn't traced.

Link: http://lkml.kernel.org/r/20181212183447.15890-1-anders.roxell@linaro.org
Signed-off-by: Anders Roxell <anders.roxell@linaro.org>
Acked-by: Dmitry Vyukov <dvyukov@google.com>
Tested-by: Dmitry Vyukov <dvyukov@google.com>
Acked-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
mpe pushed a commit that referenced this pull request Jun 21, 2021
ASan reported a memory leak caused by info_linear not being deallocated.

The info_linear was allocated during in perf_event__synthesize_one_bpf_prog().

This patch adds the corresponding free() when bpf_prog_info_node
is freed in perf_env__purge_bpf().

  $ sudo ./perf record -- sleep 5
  [ perf record: Woken up 1 times to write data ]
  [ perf record: Captured and wrote 0.025 MB perf.data (8 samples) ]

  =================================================================
  ==297735==ERROR: LeakSanitizer: detected memory leaks

  Direct leak of 7688 byte(s) in 19 object(s) allocated from:
      #0 0x4f420f in malloc (/home/user/linux/tools/perf/perf+0x4f420f)
      #1 0xc06a74 in bpf_program__get_prog_info_linear /home/user/linux/tools/lib/bpf/libbpf.c:11113:16
      #2 0xb426fe in perf_event__synthesize_one_bpf_prog /home/user/linux/tools/perf/util/bpf-event.c:191:16
      #3 0xb42008 in perf_event__synthesize_bpf_events /home/user/linux/tools/perf/util/bpf-event.c:410:9
      #4 0x594596 in record__synthesize /home/user/linux/tools/perf/builtin-record.c:1490:8
      #5 0x58c9ac in __cmd_record /home/user/linux/tools/perf/builtin-record.c:1798:8
      #6 0x58990b in cmd_record /home/user/linux/tools/perf/builtin-record.c:2901:8
      #7 0x7b2a20 in run_builtin /home/user/linux/tools/perf/perf.c:313:11
      #8 0x7b12ff in handle_internal_command /home/user/linux/tools/perf/perf.c:365:8
      #9 0x7b2583 in run_argv /home/user/linux/tools/perf/perf.c:409:2
      #10 0x7b0d79 in main /home/user/linux/tools/perf/perf.c:539:3
      torvalds#11 0x7fa357ef6b74 in __libc_start_main /usr/src/debug/glibc-2.33-8.fc34.x86_64/csu/../csu/libc-start.c:332:16

Signed-off-by: Riccardo Mancini <rickyman7@gmail.com>
Acked-by: Ian Rogers <irogers@google.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Andrii Nakryiko <andrii@kernel.org>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: John Fastabend <john.fastabend@gmail.com>
Cc: KP Singh <kpsingh@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Martin KaFai Lau <kafai@fb.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Song Liu <songliubraving@fb.com>
Cc: Yonghong Song <yhs@fb.com>
Link: http://lore.kernel.org/lkml/20210602224024.300485-1-rickyman7@gmail.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
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