Hi, Christophe.

On Wed, Aug 01, 2018 at 08:41:15AM +0200, Christophe LEROY wrote:

Le 31/07/2018 à 16:50, Murilo Opsfelder Araujo a écrit :

quoted

Remove "Instruction dump:" line by adding a prefix to display current->comm
and current->pid, along with the instructions dump.

The prefix can serve as a glue that links the instructions dump to its
originator, allowing messages to be interleaved in the logs.

Before this patch, a page fault looked like:

   pandafault[10524]: segfault (11) at 100007d0 nip 1000061c lr 7fffbd295100 code 2 in pandafault[10000000+10000]
   Instruction dump:
   4bfffeec 4bfffee8 3c401002 38427f00 fbe1fff8 f821ffc1 7c3f0b78 3d22fffe
   392988d0 f93f0020 e93f0020 39400048 <99490000> 39200000 7d234b78 383f0040

After this patch, it looks like:

   pandafault[10850]: segfault (11) at 100007d0 nip 1000061c lr 7fff9f3e5100 code 2 in pandafault[10000000+10000]
   pandafault[10850]: code: 4bfffeec 4bfffee8 3c401002 38427f00 fbe1fff8 f821ffc1 7c3f0b78 3d22fffe
   pandafault[10850]: code: 392988d0 f93f0020 e93f0020 39400048 <99490000> 39200000 7d234b78 383f0040

Signed-off-by: Murilo Opsfelder Araujo <redacted>

Does the script scripts/decode_stacktrace.sh also works with this format
change ?

I've got more feedback from Michael about this.  A better approach would be
having a new show_user_instructions(), a slightly modified version of
show_instructions(), that can be called from within show_signal_msg().

Since _exception_pkey() dies if the exception is in kernel mode, we'll be
safe to call the new show_user_instructions(), without interfering in
scripts/decode_stacktrace.sh.

Cheers
Murilo