Crash on pg_reload_conf() #10
Description
Hi,
running sqlsmith on a database with powa installed produced
crashes on pg_reload_conf(). In the backtrace below the handler
fired in a CriticalSection, where AllocSetContextCreate is
forbidden. There are probably a lot more failure modes. For
example, any elog() would be promoted to a PANIC in a Critical
Section.
IMHO powa must do this like the romans do: Don't do anything in
the signal handler besides setting a flag that a reload is
requested and do the actual work outside the handler where it is
safe to do so.
regards,
Andreas
Program terminated with signal SIGABRT, Aborted.
#0 __GI_raise (sig=sig@entry=6) at ../sysdeps/unix/sysv/linux/raise.c:58
58 ../sysdeps/unix/sysv/linux/raise.c: No such file or directory.
(gdb) bt
#0 __GI_raise (sig=sig@entry=6) at ../sysdeps/unix/sysv/linux/raise.c:58
#1 0x00007f455d6b440a in __GI_abort () at abort.c:89
#2 0x000055b745359ec3 in ExceptionalCondition (conditionName=conditionName@entry=0x55b7453dae63 "!(CritSectionCount == 0)", errorType=errorType@entry=0x55b74539d29d "FailedAssertion", fileName=fileName@e$
#3 0x000055b74537f1a2 in MemoryContextCreate (tag=tag@entry=T_AllocSetContext, size=size@entry=200, methods=methods@entry=0x55b7458023e0 <AllocSetMethods>, parent=0x55b745a55dc0, name=name@entry=0x55b745$
#4 0x000055b74537e5a0 in AllocSetContextCreate (parent=<optimized out>, name=name@entry=0x55b74551c03c "config file processing", minContextSize=minContextSize@entry=0, initBlockSize=initBlockSize@entry=8$
#5 0x000055b745379905 in ProcessConfigFile (context=PGC_SIGHUP) at guc-file.l:147
#6 0x00007f455d057dae in powa_sighup (postgres_signal_arg=<optimized out>) at powa.c:342
#7 <signal handler called>
#8 0x00007f455d75bbc0 in __close_nocancel () at ../sysdeps/unix/syscall-template.S:84
#9 0x000055b74504709c in XLogFileClose () at xlog.c:3557
#10 0x000055b74504740d in XLogWrite (WriteRqst=..., flexible=flexible@entry=0 '\000') at xlog.c:2253
#11 0x000055b74504809e in XLogFlush (record=15030149624) at xlog.c:2728
#12 0x000055b74503e6ca in RecordTransactionCommit () at xact.c:1286
#13 CommitTransaction () at xact.c:2039
#14 0x000055b74503f465 in CommitTransactionCommand () at xact.c:2874
#15 0x00007f455d057ff2 in powa_main (main_arg=<optimized out>) at powa.c:293
#16 0x000055b7451e560b in StartBackgroundWorker () at bgworker.c:742
#17 0x000055b7451f1135 in do_start_bgworker (rw=0x55b745a48ba0) at postmaster.c:5612
#18 maybe_start_bgworkers () at postmaster.c:5809
#19 0x000055b7451f14a3 in reaper (postgres_signal_arg=<optimized out>) at postmaster.c:2834
#20 <signal handler called>
#21 0x00007f455d761273 in __select_nocancel () at ../sysdeps/unix/syscall-template.S:84
#22 0x000055b744fb29be in ServerLoop () at postmaster.c:1683
#23 0x000055b7451f3153 in PostmasterMain (argc=3, argv=0x55b745a245b0) at postmaster.c:1327
#24 0x000055b744fb469d in main (argc=3, argv=0x55b745a245b0) at main.c:228