diff options
| author | Mikulas Patocka <mpatocka@redhat.com> | 2017-06-08 02:05:31 +0300 |
|---|---|---|
| committer | Ben Hutchings <ben@decadent.org.uk> | 2017-10-12 17:27:10 +0300 |
| commit | 4c99d233b2d0f847332c676cc31b03bd9225d2c5 (patch) | |
| tree | 5f2606a41d76634935384f90b72c77dffa633ef9 /drivers | |
| parent | bf97987fb94cc7d90154a217a3464d46efb8ee69 (diff) | |
| download | linux-4c99d233b2d0f847332c676cc31b03bd9225d2c5.tar.xz | |
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>
[bwh: Backported to 3.2: adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/md/raid1.c | 5 | ||||
| -rw-r--r-- | drivers/md/raid5.c | 8 |
2 files changed, 10 insertions, 3 deletions
diff --git a/drivers/md/raid1.c b/drivers/md/raid1.c index 7b75a1942159..308e8c8905c9 100644 --- a/drivers/md/raid1.c +++ b/drivers/md/raid1.c @@ -875,13 +875,16 @@ static void 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->bi_sector + bio->bi_size/512 <= mddev->suspend_lo || bio->bi_sector >= mddev->suspend_hi) 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 6056ee7984ac..2682eb95c41e 100644 --- a/drivers/md/raid5.c +++ b/drivers/md/raid5.c @@ -3823,12 +3823,16 @@ static void 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) + logical_sector < mddev->suspend_hi) { + sigset_t full, old; + sigfillset(&full); + sigprocmask(SIG_BLOCK, &full, &old); schedule(); + sigprocmask(SIG_SETMASK, &old, NULL); + } goto retry; } |