The patch titled
proc: convert task_sig() to use lock_task_sighand()
has been added to the -mm tree. Its filename is
proc-convert-task_sig-to-use-lock_task_sighand.patch
See http://www.zip.com.au/~akpm/linux/patches/stuff/added-to-mm.txt to find
out what to do about this
------------------------------------------------------
Subject: proc: convert task_sig() to use lock_task_sighand()
From: Oleg Nesterov <oleg@xxxxxxxxxx>
lock_task_sighand() can take ->siglock without holding tasklist_lock.
Signed-off-by: Oleg Nesterov <oleg@xxxxxxxxxx>
Cc: "Eric W. Biederman" <ebiederm@xxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxx>
---
fs/proc/array.c | 11 +++++------
1 files changed, 5 insertions(+), 6 deletions(-)
diff -puN fs/proc/array.c~proc-convert-task_sig-to-use-lock_task_sighand fs/proc/array.c
--- a/fs/proc/array.c~proc-convert-task_sig-to-use-lock_task_sighand
+++ a/fs/proc/array.c
@@ -244,6 +244,7 @@ static void collect_sigign_sigcatch(stru
static inline char * task_sig(struct task_struct *p, char *buffer)
{
+ unsigned long flags;
sigset_t pending, shpending, blocked, ignored, caught;
int num_threads = 0;
unsigned long qsize = 0;
@@ -255,10 +256,8 @@ static inline char * task_sig(struct tas
sigemptyset(&ignored);
sigemptyset(&caught);
- /* Gather all the data with the appropriate locks held */
- read_lock(&tasklist_lock);
- if (p->sighand) {
- spin_lock_irq(&p->sighand->siglock);
+ rcu_read_lock();
+ if (lock_task_sighand(p, &flags)) {
pending = p->pending.signal;
shpending = p->signal->shared_pending.signal;
blocked = p->blocked;
@@ -266,9 +265,9 @@ static inline char * task_sig(struct tas
num_threads = atomic_read(&p->signal->count);
qsize = atomic_read(&p->user->sigpending);
qlim = p->signal->rlim[RLIMIT_SIGPENDING].rlim_cur;
- spin_unlock_irq(&p->sighand->siglock);
+ unlock_task_sighand(p, &flags);
}
- read_unlock(&tasklist_lock);
+ rcu_read_unlock();
buffer += sprintf(buffer, "Threads:\t%d\n", num_threads);
buffer += sprintf(buffer, "SigQ:\t%lu/%lu\n", qsize, qlim);
_
Patches currently in -mm which might be from oleg@xxxxxxxxxx are
git-block.patch
pid-implement-transfer_pid-and-use-it-to-simplify-de_thread.patch
pid-remove-temporary-debug-code-in-attach_pid.patch
rtmutex-clean-up-and-remove-some-extra-spinlocks.patch
rtmutex-clean-up-and-remove-some-extra-spinlocks-more.patch
elf_core_dump-dont-take-tasklist_lock.patch
elf_fdpic_core_dump-dont-take-tasklist_lock.patch
has_stopped_jobs-cleanup.patch
__dequeue_signal-cleanup.patch
do_sched_setscheduler-dont-take-tasklist_lock.patch
introduce-is_rt_policy-helper.patch
sched_setscheduler-fix-policy-checks.patch
reparent_to_init-use-has_rt_policy.patch
copy_process-cosmetic-ioprio-tweak.patch
futex_find_get_task-dont-take-tasklist_lock.patch
sys_get_robust_list-dont-take-tasklist_lock.patch
set-exit_dead-state-in-do_exit-not-in-schedule.patch
kill-pf_dead-flag.patch
introduce-task_dead-state.patch
select_bad_process-kill-a-bogus-pf_dead-task_dead-check.patch
select_bad_process-cleanup-releasing-check.patch
oom_kill_task-cleanup-mm-checks.patch
audit-accounting-tty-locking.patch
proc-readdir-race-fix-take-3-race-fix.patch
simplify-pid-iterators.patch
proc-convert-task_sig-to-use-lock_task_sighand.patch
proc-convert-do_task_stat-to-use-lock_task_sighand.patch
proc-drop-tasklist-lock-in-task_state.patch
proc-properly-compute-tgid_offset.patch
proc-remove-trailing-blank-entry-from-pid_entry-arrays.patch
proc-remove-the-useless-smp-safe-comments-from-proc.patch
proc-comment-what-proc_fill_cache-does.patch
rcu-simplify-improve-batch-tuning.patch
pidhash-temporary-debug-checks.patch
-
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