diff options
| author | Mikulas Patocka <mpatocka@redhat.com> | 2017-06-07 19:05:31 -0400 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2017-07-27 15:08:01 -0700 |
| commit | 03c1d9d45582e8a0991747a6f7a3a235b39b3e2b (patch) | |
| tree | af9d6fe6ab6b3cb8a9ecca06ff17f7718b31e2ca | |
| parent | dbc969ca944f1a3f61af083f4126bb5408d37b4c (diff) | |
md: don't use flush_signals in userspace processes
commit f9c79bc05a2a91f4fba8bfd653579e066714b1ec upstream.
The function flush_signals clears all pending signals for the process. It
may be used by kernel threads when we need to prepare a kernel thread for
responding to signals. However using this function for an userspaces
processes is incorrect - clearing signals without the program expecting it
can cause misbehavior.
The raid1 and raid5 code uses flush_signals in its request routine because
it wants to prepare for an interruptible wait. This patch drops
flush_signals and uses sigprocmask instead to block all signals (including
SIGKILL) around the schedule() call. The signals are not lost, but the
schedule() call won't respond to them.
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Acked-by: NeilBrown <neilb@suse.com>
Signed-off-by: Shaohua Li <shli@fb.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | drivers/md/raid1.c | 5 | ||||
| -rw-r--r-- | drivers/md/raid5.c | 5 |
2 files changed, 8 insertions, 2 deletions
diff --git a/drivers/md/raid1.c b/drivers/md/raid1.c index 29e2df5cd77b..81a78757bc78 100644 --- a/drivers/md/raid1.c +++ b/drivers/md/raid1.c @@ -1073,7 +1073,7 @@ static void raid1_make_request(struct mddev *mddev, struct bio * bio) */ DEFINE_WAIT(w); for (;;) { - flush_signals(current); + sigset_t full, old; prepare_to_wait(&conf->wait_barrier, &w, TASK_INTERRUPTIBLE); if (bio_end_sector(bio) <= mddev->suspend_lo || @@ -1082,7 +1082,10 @@ static void raid1_make_request(struct mddev *mddev, struct bio * bio) !md_cluster_ops->area_resyncing(mddev, WRITE, bio->bi_iter.bi_sector, bio_end_sector(bio)))) break; + sigfillset(&full); + sigprocmask(SIG_BLOCK, &full, &old); schedule(); + sigprocmask(SIG_SETMASK, &old, NULL); } finish_wait(&conf->wait_barrier, &w); } diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c index f34ad2be66a1..a613eea4b8a5 100644 --- a/drivers/md/raid5.c +++ b/drivers/md/raid5.c @@ -5300,12 +5300,15 @@ static void raid5_make_request(struct mddev *mddev, struct bio * bi) * userspace, we want an interruptible * wait. */ - flush_signals(current); prepare_to_wait(&conf->wait_for_overlap, &w, TASK_INTERRUPTIBLE); if (logical_sector >= mddev->suspend_lo && logical_sector < mddev->suspend_hi) { + sigset_t full, old; + sigfillset(&full); + sigprocmask(SIG_BLOCK, &full, &old); schedule(); + sigprocmask(SIG_SETMASK, &old, NULL); do_prepare = true; } goto retry; |