[PATCH v2] printk: Add a short description string to kmsg_dump()

[Michael Ellerman]

Jocelyn Falempe <jfalempe at redhat.com> writes:
> On 02/07/2024 14:26, Jocelyn Falempe wrote:
>> kmsg_dump doesn't forward the panic reason string to the kmsg_dumper
>> callback.
>> This patch adds a new struct kmsg_dump_detail, that will hold the
>> reason and description, and pass it to the dump() callback.
>> 
>> To avoid updating all kmsg_dump() call, it adds a kmsg_dump_desc()
>> function and a macro for backward compatibility.
>> 
>> I've written this for drm_panic, but it can be useful for other
>> kmsg_dumper.
>> It allows to see the panic reason, like "sysrq triggered crash"
>> or "VFS: Unable to mount root fs on xxxx" on the drm panic screen.
>> 
>> v2:
>>   * Use a struct kmsg_dump_detail to hold the reason and description
>>     pointer, for more flexibility if we want to add other parameters.
>>     (Kees Cook)
>>   * Fix powerpc/nvram_64 build, as I didn't update the forward
>>     declaration of oops_to_nvram()
>> 
>> Signed-off-by: Jocelyn Falempe <jfalempe at redhat.com>
>> ---
>>   arch/powerpc/kernel/nvram_64.c             |  8 ++++----
>>   arch/powerpc/platforms/powernv/opal-kmsg.c |  4 ++--
>>   arch/um/kernel/kmsg_dump.c                 |  2 +-
>>   drivers/gpu/drm/drm_panic.c                |  4 ++--
>>   drivers/hv/hv_common.c                     |  4 ++--
>>   drivers/mtd/mtdoops.c                      |  2 +-
>>   fs/pstore/platform.c                       | 10 +++++-----
>>   include/linux/kmsg_dump.h                  | 22 +++++++++++++++++++---
>>   kernel/panic.c                             |  2 +-
>>   kernel/printk/printk.c                     | 11 ++++++++---
>>   10 files changed, 45 insertions(+), 24 deletions(-)
>
...
> Gentle ping, I need reviews from powerpc, usermod linux, mtd, pstore and 
> hyperv, to be able to push it in the drm-misc tree.

For a simple mechanical change like that you don't need reviews from
every subsystem. As long as it's posted to each subsystem and there's
been a bit of time for folks to see it, and the build robots to build
it, that should be sufficient. Otherwise you could be waiting forever.

cheers