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From:   ebiederm@xmission.com (Eric W. Biederman)
To:     Linus Torvalds <torvalds@linux-foundation.org>
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Date:   Thu, 24 Jun 2021 14:00:22 -0500
In-Reply-To: <875yy3850g.fsf_-_@disp2133> (Eric W. Biederman's message of
        "Thu, 24 Jun 2021 13:57:35 -0500")
Message-ID: <87lf6z6qbd.fsf_-_@disp2133>
User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/26.1 (gnu/linux)
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Content-Type: text/plain
Subject: [PATCH 3/9] signal/seccomp: Dump core when there is only one live thread
Precedence: bulk


Replace get_nr_threads with atomic_read(&current->signal->live) as
that is a more accurate number that is decremented sooner.

Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
---
 kernel/seccomp.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/kernel/seccomp.c b/kernel/seccomp.c
index 3e06d4628d98..5301eca670a0 100644
--- a/kernel/seccomp.c
+++ b/kernel/seccomp.c
@@ -1241,7 +1241,7 @@ static int __seccomp_filter(int this_syscall, const struct seccomp_data *sd,
 		seccomp_log(this_syscall, SIGSYS, action, true);
 		/* Dump core only if this is the last remaining thread. */
 		if (action != SECCOMP_RET_KILL_THREAD ||
-		    get_nr_threads(current) == 1) {
+		    (atomic_read(&current->signal->live) == 1)) {
 			/* Show the original registers in the dump. */
 			syscall_rollback(current, current_pt_regs());
 			/* Trigger a coredump with SIGSYS */
-- 
2.20.1