Re: [PATCHv3] fs/proc: allow reporting eip/esp for all coredumping threads

From: Andrew Morton
Date: Wed May 29 2019 - 21:17:51 EST


(ooh, Greg, let me do it!)

On Thu, 30 May 2019 02:58:59 +0200 John Ogness <john.ogness@xxxxxxxxxxxxx> wrote:

> Commit 0a1eb2d474ed ("fs/proc: Stop reporting eip and esp in
> /proc/PID/stat") stopped reporting eip/esp and commit fd7d56270b52
> ("fs/proc: Report eip/esp in /prod/PID/stat for coredumping")
> reintroduced the feature to fix a regression with userspace core dump
> handlers (such as minicoredumper).
>
> Because PF_DUMPCORE is only set for the primary thread, this didn't fix
> the original problem for secondary threads. Allow reporting the eip/esp
> for all threads by checking for PF_EXITING as well. This is set for all
> the other threads when they are killed. coredump_wait() waits for all
> the tasks to become inactive before proceeding to invoke a core dumper.
>
> Fixes: fd7d56270b526ca3 ("fs/proc: Report eip/esp in /prod/PID/stat for coredumping")
> Reported-by: Jan Luebbe <jlu@xxxxxxxxxxxxxx>
> Signed-off-by: John Ogness <john.ogness@xxxxxxxxxxxxx>
> ---
> This is a rework of Jan's v1 patch that allows accessing eip/esp of all
> the threads without risk of the task still executing on a CPU.
>
> The code chagnes are the same as v2. With v3 I included a "Fixes" tag,
> fixed a typo in the commit message, and Cc'd stable.

No, the way to Cc stable is to add

Cc: <stable@xxxxxxxxxxxxxxx> to the changelog metadata.

I've made these changes to my copy of this patch, thanks.