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| author | Oleg Nesterov <oleg@redhat.com> | 2011-08-03 16:21:05 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2011-08-03 14:25:20 -1000 |
| commit | a7295898a1d2e501427f557111c2b4bdfc90b1ed (patch) | |
| tree | 143ce6e69d8aa795494120a00c62ca0ade8bac40 | |
| parent | dfc428b656c4693a2334a8d9865b430beddb562a (diff) | |
| download | olio-linux-3.10-a7295898a1d2e501427f557111c2b4bdfc90b1ed.tar.xz olio-linux-3.10-a7295898a1d2e501427f557111c2b4bdfc90b1ed.zip | |
taskstats: add_del_listener() should ignore !valid listeners
When send_cpu_listeners() finds the orphaned listener it marks it as
!valid and drops listeners->sem. Before it takes this sem for writing,
s->pid can be reused and add_del_listener() can wrongly try to re-use
this entry.
Change add_del_listener() to check ->valid = T.
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Reviewed-by: Vasiliy Kulikov <segoon@openwall.com>
Acked-by: Balbir Singh <bsingharora@gmail.com>
Cc: Jerome Marchand <jmarchan@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| -rw-r--r-- | kernel/taskstats.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/kernel/taskstats.c b/kernel/taskstats.c index a09a54936f1..e19ce1454ee 100644 --- a/kernel/taskstats.c +++ b/kernel/taskstats.c @@ -304,7 +304,7 @@ static int add_del_listener(pid_t pid, const struct cpumask *mask, int isadd) listeners = &per_cpu(listener_array, cpu); down_write(&listeners->sem); list_for_each_entry(s2, &listeners->list, list) { - if (s2->pid == pid) + if (s2->pid == pid && s2->valid) goto exists; } list_add(&s->list, &listeners->list); |