On Wed, Mar 13, 2024 at 08:04:36PM -0700, Kees Cook wrote:
On Wed, Mar 13, 2024 at 12:42:11PM -0400, Sasha Levin wrote:
From: Kees Cook <keescook@xxxxxxxxxxxx>
[ Upstream commit 4e046156792c26bef8a4e30be711777fc8578257 ]
The implementations of get_wchan() can be expensive. The only information
imparted here is whether or not a process is currently blocked in the
scheduler (and even this doesn't need to be exact). Avoid doing the
heavy lifting of stack walking and just report that information by using
task_is_running().
Signed-off-by: Kees Cook <keescook@xxxxxxxxxxxx>
Signed-off-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx>
Link: https://lkml.kernel.org/r/20211008111626.211281780@xxxxxxxxxxxxx
Stable-dep-of: 60f92acb60a9 ("fs/proc: do_task_stat: move thread_group_cputime_adjusted() outside of lock_task_sighand()")
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
Looks fine to me. Can you double-check that commit
54354c6a9f7f ("Revert "proc/wchan: use printk format instead of lookup_symbol_name()"")
is already backported too?
Yup, it's there too.
--
Thanks,
Sasha
