[PATCH 0/7] powerpc: Modernize unhandled signals message

From: Murilo Opsfelder Araujo
Date: Tue Jul 24 2018 - 15:28:00 EST

Hi, everyone.

This series was inspired by the need to modernize and display more
informative messages about unhandled signals.

The "unhandled signal NN" is not very informative. We thought it would
be helpful adding a human-readable message describing what the signal
number means, printing the VMA address, and dumping the instructions.

We can add more informative messages, like informing what each code of a
SIGSEGV signal means. We are open to suggestions.

I have collected some early feedback from Michael Ellerman about this
series and would love to hear more feedback from you all.

Before this series:

Jul 24 13:01:07 localhost kernel: pandafault[5989]: unhandled signal 11 at 00000000100007d0 nip 000000001000061c lr 00003fff85a75100 code 2

After this series:

Jul 24 13:08:01 localhost kernel: pandafault[10758]: segfault (11) at 00000000100007d0 nip 000000001000061c lr 00007fffabc85100 code 2 in pandafault[10000000+10000]
Jul 24 13:08:01 localhost kernel: Instruction dump:
Jul 24 13:08:01 localhost kernel: 4bfffeec 4bfffee8 3c401002 38427f00 fbe1fff8 f821ffc1 7c3f0b78 3d22fffe
Jul 24 13:08:01 localhost kernel: 392988d0 f93f0020 e93f0020 39400048 <99490000> 39200000 7d234b78 383f0040


Murilo Opsfelder Araujo (7):
powerpc/traps: Print unhandled signals in a separate function
powerpc/traps: Return early in show_signal_msg()
powerpc/reg: Add REG_FMT definition
powerpc/traps: Use REG_FMT in show_signal_msg()
powerpc/traps: Print VMA for unhandled signals
powerpc/traps: Print signal name for unhandled signals
powerpc/traps: Show instructions on exceptions

arch/powerpc/include/asm/reg.h | 6 +++
arch/powerpc/include/asm/stacktrace.h | 7 +++
arch/powerpc/kernel/process.c | 28 +++++-----
arch/powerpc/kernel/traps.c | 73 +++++++++++++++++++++++----
4 files changed, 89 insertions(+), 25 deletions(-)
create mode 100644 arch/powerpc/include/asm/stacktrace.h