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

From: Michael Ellerman
Date: Fri Jul 12 2024 - 08:26:32 EST


Jocelyn Falempe <jfalempe@xxxxxxxxxx> 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@xxxxxxxxxx>
>> ---
>> 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