Gitweb:
http://git.kernel.org/git/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=f9ee228bdc82cff8ea1ec00fd952890e00679dd8
Commit: f9ee228bdc82cff8ea1ec00fd952890e00679dd8
Parent: 834d216e1f804560bd1421c511ad168d7c24b01d
Author: Oleg Nesterov <[EMAIL PROTECTED]>
AuthorDate: Wed Aug 22 14:01:48 2007 -0700
Committer: Linus Torvalds <[EMAIL PROTECTED]>
CommitDate: Wed Aug 22 19:52:46 2007 -0700
signalfd: make it group-wide, fix posix-timers scheduling
With this patch any thread can dequeue its own private signals via signalfd,
even if it was created by another sub-thread.
To do so, we pass "current" to dequeue_signal() if the caller is from the
same
thread group. This also fixes the scheduling of posix timers broken by the
previous patch.
If the caller doesn't belong to this thread group, we can't handle
__SI_TIMER
case properly anyway. Perhaps we should forbid the cross-process signalfd
usage
and convert ctx->tsk to ctx->sighand.
Signed-off-by: Oleg Nesterov <[EMAIL PROTECTED]>
Cc: Benjamin Herrenschmidt <[EMAIL PROTECTED]>
Cc: Davide Libenzi <[EMAIL PROTECTED]>
Cc: Ingo Molnar <[EMAIL PROTECTED]>
Cc: Michael Kerrisk <[EMAIL PROTECTED]>
Cc: Roland McGrath <[EMAIL PROTECTED]>
Cc: Thomas Gleixner <[EMAIL PROTECTED]>
Cc: <[EMAIL PROTECTED]>
Signed-off-by: Andrew Morton <[EMAIL PROTECTED]>
Signed-off-by: Linus Torvalds <[EMAIL PROTECTED]>
---
fs/exec.c | 9 ++-------
fs/signalfd.c | 14 ++++++++++----
2 files changed, 12 insertions(+), 11 deletions(-)
diff --git a/fs/exec.c b/fs/exec.c
index ce62f7b..af4361c 100644
--- a/fs/exec.c
+++ b/fs/exec.c
@@ -780,18 +780,12 @@ static int de_thread(struct task_struct *tsk)
int count;
/*
- * Tell all the sighand listeners that this sighand has
- * been detached. The signalfd_detach() function grabs the
- * sighand lock, if signal listeners are present on the sighand.
- */
- signalfd_detach(tsk);
-
- /*
* If we don't share sighandlers, then we aren't sharing anything
* and we can just re-use it all.
*/
if (atomic_read(&oldsighand->count) <= 1) {
BUG_ON(atomic_read(&sig->count) != 1);
+ signalfd_detach(tsk);
exit_itimers(sig);
return 0;
}
@@ -930,6 +924,7 @@ static int de_thread(struct task_struct *tsk)
sig->flags = 0;
no_thread_group:
+ signalfd_detach(tsk);
exit_itimers(sig);
if (leader)
release_task(leader);
diff --git a/fs/signalfd.c b/fs/signalfd.c
index 7b941ab..a8e293d 100644
--- a/fs/signalfd.c
+++ b/fs/signalfd.c
@@ -56,12 +56,18 @@ static int signalfd_lock(struct signalfd_ctx *ctx, struct
signalfd_lockctx *lk)
sighand = lock_task_sighand(lk->tsk, &lk->flags);
rcu_read_unlock();
- if (sighand && !ctx->tsk) {
+ if (!sighand)
+ return 0;
+
+ if (!ctx->tsk) {
unlock_task_sighand(lk->tsk, &lk->flags);
- sighand = NULL;
+ return 0;
}
- return sighand != NULL;
+ if (lk->tsk->tgid == current->tgid)
+ lk->tsk = current;
+
+ return 1;
}
static void signalfd_unlock(struct signalfd_lockctx *lk)
@@ -331,7 +337,7 @@ asmlinkage long sys_signalfd(int ufd, sigset_t __user
*user_mask, size_t sizemas
init_waitqueue_head(&ctx->wqh);
ctx->sigmask = sigmask;
- ctx->tsk = current;
+ ctx->tsk = current->group_leader;
sighand = current->sighand;
/*
-
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