random-sig randomly failing with gdbserver

random-sig randomly failing with gdbserver

[Philippe Waroquiers]

gdb.base/random-sig.exp (frequently) randomly fails when running with gdbserver,
when running multiple times
  make check RUNTESTFLAGS="--target_board native-gdbserver random-signal.exp"
It looks like it can fail for at least three reasons

A successful run gives:
  (gdb) PASS: gdb.base/random-signal.exp: watch v
  continue
  Continuing.
  PASS: gdb.base/random-signal.exp: continue
  ^C
  Program received signal SIGINT, Interrupt.
  main () at ./gdb.base/random-signal.c:28
  28	    ;
  (gdb) PASS: gdb.base/random-signal.exp: stop with control-c

A failing run gives:
  (gdb) PASS: gdb.base/random-signal.exp: watch v
  continue
  Continuing.
  PASS: gdb.base/random-signal.exp: continue
  ^Cmain () at ./gdb.base/random-signal.c:28
  28	    ;
  Quit
  (gdb) FAIL: gdb.base/random-signal.exp: stop with control-c
  testcase ./gdb.base/random-signal.exp completed in 1 seconds


It can also fail with:
  (gdb) PASS: gdb.base/random-signal.exp: watch v
  continue
  Continuing.
  PASS: gdb.base/random-signal.exp: continue
  ^CFAIL: gdb.base/random-signal.exp: stop with control-c (timeout)
  testcase ./gdb.base/random-signal.exp completed in 11 seconds

Or fail with
  (gdb) PASS: gdb.base/random-signal.exp: watch v
  continue
  Continuing.
  PASS: gdb.base/random-signal.exp: continue
  ^CError evaluating expression for watchpoint 2
  Quit
  Watchpoint 2 deleted.
  main () at ./gdb.base/random-signal.c:28
  28	    ;
  (gdb) FAIL: gdb.base/random-signal.exp: stop with control-c
  testcase ./gdb.base/random-signal.exp completed in 1 seconds


Unclear what exactly happens. I suspect a race condition between
gdbserver reporting that the inferior stopped (to examine the
software watchpoint) and gdb sending at the same time
the interrupt, and expecting a SIGINT, but instead receiving
the stopped condition from gdbserver.

Philippe

Re: random-sig randomly failing with gdbserver

[Jan Kratochvil]

On Fri, 30 Aug 2013 13:20:28 +0200, Philippe Waroquiers wrote:
> gdb.base/random-sig.exp (frequently) randomly fails when running with gdbserver,

This is a known issue, I see it daily from my nightly runs:
	CTRL-C with set debug remote often crashes GDB
	https://sourceware.org/bugzilla/show_bug.cgi?id=15297#c2
->
	[patchv2 2/2] Fix CTRL-C for remote.c (PR remote/15297)
	http://sourceware.org/ml/gdb-patches/2013-06/msg00943.html

Still it is not 100% reliable, it was discussed with Pedro off-list, planning
to send some update.


Jan

Re: random-sig randomly failing with gdbserver

[Pedro Alves]

On 08/30/2013 12:36 PM, Jan Kratochvil wrote:

> Still it is not 100% reliable, it was discussed with Pedro off-list, planning
> to send some update.

Yeah, I'm working on it, but I don't have the update ready yet.

-- 
Pedro Alves

Re: random-sig randomly failing with gdbserver

[Pedro Alves]

On 08/30/2013 12:36 PM, Jan Kratochvil wrote:

> Still it is not 100% reliable, it was discussed with Pedro off-list, planning
> to send some update.

Yeah, I've working on it, but I don't have the update ready yet.

-- 
Pedro Alves