Re: [PATCH 1/1] binfmt_elf, coredump: Log the reason of the failed core dumps

Roman Kisel
2024-06-18T15:49:32Z

On 6/17/2024 4:52 PM, Kees Cook wrote:
> On Mon, Jun 17, 2024 at 04:41:30PM -0700, Roman Kisel wrote:
>> Missing, failed, or corrupted core dumps might impede crash
>> investigations. To improve reliability of that process and consequently
>> the programs themselves, one needs to trace the path from producing
>> a core dumpfile to analyzing it. That path starts from the core dump file
>> written to the disk by the kernel or to the standard input of a user
>> mode helper program to which the kernel streams the coredump contents.
>> There are cases where the kernel will interrupt writing the core out or
>> produce a truncated/not-well-formed core dump.
>
> Hm, I'm all for better diagnostics, but they need to be helpful and not
> be a risk to the system. All the added "pr_*()" calls need to use the
> _ratelimited variant to avoid a user inducing massive spam to the system
> logs. And please standardize the reporting to include information about
> the task that is dumping. Otherwise the logging isn't useful for anyone
> reading it. Something that includes pid and task->comm at the very
> least. :)
Appreciate your suggestions very much! Rate-limiting has definitely
slipped off my mind, my bad. Will also fix the reporting format to make
it useful.

>
> For example, see report_mem_rw_reject() in
> https://lore.kernel.org/lkml/20240613133937.2352724-2-adrian.ratiu@collabora.com/
Thanks, that's awesome!

>
> -Kees
>

--
Thank you,
Roman