Eric Lee / smarc-fsl-linux-kernel

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Commit c8e85b4f4b9ee23bf0e79bdeb3da274a0f9c663f

Authored by Oleg Nesterov
Committed by Linus Torvalds
1 parent 84a881657d
Exists in master and in 39 other branches 8mp-imx_5.4.70_2.3.0, 8qm-imx_5.4.70_2.3.0, emb_imx_lf-5.15.y, emb_lf-6.1.y, imx_3.0.35_4.1.0, imx_3.10.17_1.0.1_ga, imx_3.10.53_1.1.0_ga, imx_3.14.28_1.0.0_ga, imx_4.1.15_1.0.0_ga, pitx_8mp_lf-5.10.y, rt-smarc-imx_4.1.15_1.0.0_ga, rt_linux_5.15.71, smarc-8m-android-11.0.0_2.0.0, smarc-imx6_4.14.98_2.0.0_ga, smarc-imx6_4.9.88_2.0.0_ga, smarc-imx7_4.14.98_2.0.0_ga, smarc-imx7_4.9.11_1.0.0_ga, smarc-imx7_4.9.88_2.0.0_ga, smarc-imx_3.10.53_1.1.0_ga, smarc-imx_3.14.28_1.0.0_ga, smarc-imx_4.1.15_1.0.0_ga, smarc-imx_4.9.11_1.0.0_ga, smarc-imx_4.9.51_imx8m_ga, smarc-imx_4.9.88_2.0.0_ga, smarc-m6.0.1_2.1.0-ga, smarc-n7.1.2_2.0.0-ga, smarc-rel_imx_4.1.15_1.2.0_ga, smarc_8m_00d0_imx_4.14.98_2.0.0_ga, smarc_8m_imx_4.14.78_1.0.0_ga, smarc_8m_imx_4.14.98_2.0.0_ga, smarc_8m_imx_4.19.35_1.1.0, smarc_8mm_imx_4.14.78_1.0.0_ga, smarc_8mm_imx_4.14.98_2.0.0_ga, smarc_8mm_imx_4.19.35_1.1.0, smarc_8mm_imx_5.4.24_2.1.0, smarc_8mp_lf-5.10.y, smarc_8mq_imx_5.4.24_2.1.0, smarc_8mq_lf-5.10.y, smarc_imx_lf-5.15.y

posix timers: sigqueue_free: don't free sigqueue if it is queued 

Currently sigqueue_free() removes sigqueue from list, but doesn't cancel the
pending signal. This is not consistent, the task should either receive the
"full" signal along with siginfo_t, or it shouldn't receive the signal at all.

Change sigqueue_free() to clear SIGQUEUE_PREALLOC but leave sigqueue on list
if it is queued.

This is a user-visible change. If the signal is blocked, it stays queued
after sys_timer_delete() until unblocked with the "stale" si_code/si_value,
and of course it is still counted wrt RLIMIT_SIGPENDING which also limits
the number of posix timers.

Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru>
Cc: Austin Clements <amdragon+kernelbugzilla@mit.edu>
Cc: Roland McGrath <roland@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Showing 1 changed file with 10 additions and 6 deletions Side-by-side Diff

... ... @@ -1240,18 +1240,22 @@
1240 1240  
1241 1241 BUG_ON(!(q->flags & SIGQUEUE_PREALLOC));
1242 1242 /*
1243   - * If the signal is still pending remove it from the
1244   - * pending queue. We must hold ->siglock while testing
1245   - * q->list to serialize with collect_signal() or with
  1243 + * We must hold ->siglock while testing q->list
  1244 + * to serialize with collect_signal() or with
1246 1245 * __exit_signal()->flush_sigqueue().
1247 1246 */
1248 1247 spin_lock_irqsave(lock, flags);
  1248 + q->flags &= ~SIGQUEUE_PREALLOC;
  1249 + /*
  1250 + * If it is queued it will be freed when dequeued,
  1251 + * like the "regular" sigqueue.
  1252 + */
1249 1253 if (!list_empty(&q->list))
1250   - list_del_init(&q->list);
  1254 + q = NULL;
1251 1255 spin_unlock_irqrestore(lock, flags);
1252 1256  
1253   - q->flags &= ~SIGQUEUE_PREALLOC;
1254   - __sigqueue_free(q);
  1257 + if (q)
  1258 + __sigqueue_free(q);
1255 1259 }
1256 1260  
1257 1261 int send_sigqueue(struct sigqueue *q, struct task_struct *t, int group)