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| author | Oleg Nesterov <oleg@tv-sign.ru> | 2008-01-14 22:02:37 +0100 |
|---|---|---|
| committer | Linus Torvalds <torvalds@woody.linux-foundation.org> | 2008-01-14 22:23:00 +0100 |
| commit | a98fdcef941e107eeabae622d85a1f476f25a160 (patch) | |
| tree | 1702a6e810016eea5e995eb7c91a101688e8c59c /fs/proc/array.c | |
| parent | Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dto... (diff) | |
| download | linux-a98fdcef941e107eeabae622d85a1f476f25a160.tar.xz linux-a98fdcef941e107eeabae622d85a1f476f25a160.zip | |
fix the "remove task_ppid_nr_ns" commit
Commit 84427eaef1fb91704c7112bdb598c810003b99f3 (remove task_ppid_nr_ns)
moved the task_tgid_nr_ns(task->real_parent) outside of lock_task_sighand().
This is wrong, ->real_parent could be freed/reused.
Both ->parent/real_parent point to nothing after __exit_signal() because
we remove the child from ->children list, and thus the child can't be
reparented when its parent exits.
rcu_read_lock() protects ->parent/real_parent, but _only_ if we know it was
valid before we take rcu lock.
Revert this part of the patch.
Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'fs/proc/array.c')
| -rw-r--r-- | fs/proc/array.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/fs/proc/array.c b/fs/proc/array.c index 810eb8fd6500..eb97f2897e2b 100644 --- a/fs/proc/array.c +++ b/fs/proc/array.c @@ -426,7 +426,6 @@ static int do_task_stat(struct task_struct *task, char *buffer, int whole) cgtime = gtime = cputime_zero; rcu_read_lock(); - ppid = task_tgid_nr_ns(task->real_parent, ns); if (lock_task_sighand(task, &flags)) { struct signal_struct *sig = task->signal; @@ -465,6 +464,7 @@ static int do_task_stat(struct task_struct *task, char *buffer, int whole) } sid = task_session_nr_ns(task, ns); + ppid = task_tgid_nr_ns(task->real_parent, ns); pgid = task_pgrp_nr_ns(task, ns); unlock_task_sighand(task, &flags); |