Re: [PATCH v3 0/2] binfmt_elf, coredump: Log the reason of the failed core dumps

[Roman Kisel <romank@linux.microsoft.com>]

On 7/19/2024 10:26 AM, Kees Cook wrote:
> On Thu, Jul 18, 2024 at 11:27:23AM -0700, Roman Kisel wrote:
>> A powerful way to diagnose crashes is to analyze the core dump produced upon
>> the failure. Missing or malformed core dump files hinder these investigations.
>> I'd like to propose changes that add logging as to why the kernel would not
>> finish writing out the core dump file.
>>
>> To help in diagnosing the user mode helper not writing out the entire coredump
>> contents, the changes also log short statistics on the dump collection. I'd
>> advocate for keeping this at the info level on these grounds.
>>
>> For validation, I built the kernel and a simple user space to exercize the new
>> code.
>>
>> [V3]
>>    - Standartized the existing logging to report TGID and comm consistently
>>    - Fixed compiler warnings for the 32-bit systems (used %zd in the format strings)
>>
>> [V2]
>>    https://lore.kernel.org/all/20240712215223.605363-1-romank@linux.microsoft.com/
>>    - Used _ratelimited to avoid spamming the system log
>>    - Added comm and PID to the log messages
>>    - Added logging to the failure paths in dump_interrupted, dump_skip, and dump_emit
>>    - Fixed compiler warnings produced when CONFIG_COREDUMP is disabled
>>
>> [V1]
>>    https://lore.kernel.org/all/20240617234133.1167523-1-romank@linux.microsoft.com/
>>
>> Roman Kisel (2):
>>    coredump: Standartize and fix logging
>>    binfmt_elf, coredump: Log the reason of the failed core dumps
>>
>>   fs/binfmt_elf.c          |  48 +++++++++----
>>   fs/coredump.c            | 150 +++++++++++++++++++++++++++------------
>>   include/linux/coredump.h |  30 +++++++-
>>   kernel/signal.c          |  21 +++++-
>>   4 files changed, 188 insertions(+), 61 deletions(-)
> 
> This looks good to me! I'll put this in -next once the merge window
> closes. Thanks!
> 
Kees, thank you for your guidance!

> -Kees
> 

-- 
Thank you,
Roman