mirrors
/
linux-stable
mirror of https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
1
0
Fork 0
Code Issues Releases Wiki Activity

signal handling: don't use BUG_ON() for debugging 

[ Upstream commit a382f8fee4 ]

These are indeed "should not happen" situations, but it turns out recent
changes made the 'task_is_stopped_or_trace()' case trigger (fix for that
exists, is pending more testing), and the BUG_ON() makes it
unnecessarily hard to actually debug for no good reason.

It's been that way for a long time, but let's make it clear: BUG_ON() is
not good for debugging, and should never be used in situations where you
could just say "this shouldn't happen, but we can continue".

Use WARN_ON_ONCE() instead to make sure it gets logged, and then just
continue running.  Instead of making the system basically unusuable
because you crashed the machine while potentially holding some very core
locks (eg this function is commonly called while holding 'tasklist_lock'
for writing).

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
This commit is contained in:
Linus Torvalds 2022-07-06 12:20:59 -07:00 committed by Greg Kroah-Hartman
parent b3d7c509bc
commit c5a7f95497
1 changed files with 4 additions and 4 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

8
kernel/signal.c
View File

@ -1647,12 +1647,12 @@ bool do_notify_parent(struct task_struct *tsk, int sig)
bool autoreap = false;
cputime_t utime, stime;
BUG_ON(sig == -1);
WARN_ON_ONCE(sig == -1);
/* do_notify_parent_cldstop should have been called instead. */
BUG_ON(task_is_stopped_or_traced(tsk));
/* do_notify_parent_cldstop should have been called instead. */
WARN_ON_ONCE(task_is_stopped_or_traced(tsk));
BUG_ON(!tsk->ptrace &&
WARN_ON_ONCE(!tsk->ptrace &&
(tsk->group_leader != tsk || !thread_group_empty(tsk)));
if (sig != SIGCHLD) {