Hello!
Some simplification in checking signal delivery against concurrent
exit. Instead of using get_task_struct_rcu(), which increments
the task_struct reference count, check the reference count after
acquiring sighand lock.
Signed-off-by: <[email protected]>
---
signal.c | 12 ++++++------
1 files changed, 6 insertions(+), 6 deletions(-)
diff -urpNa linux-2.6.14-rc5-rt5/kernel/signal.c linux-2.6.14-rc5-rt5-ckhand/kernel/signal.c
--- linux-2.6.14-rc5-rt5/kernel/signal.c 2005-10-24 05:59:08.000000000 -0700
+++ linux-2.6.14-rc5-rt5-ckhand/kernel/signal.c 2005-10-31 15:46:14.000000000 -0800
@@ -1150,19 +1150,19 @@ int group_send_sig_info(int sig, struct
retry:
ret = check_kill_permission(sig, info, p);
- if (!ret && sig && (sp = p->sighand)) {
- if (!get_task_struct_rcu(p)) {
- return -ESRCH;
- }
+ if (!ret && sig && (sp = rcu_dereference(p->sighand))) {
spin_lock_irqsave(&sp->siglock, flags);
if (p->sighand != sp) {
spin_unlock_irqrestore(&sp->siglock, flags);
- put_task_struct(p);
goto retry;
}
+ if ((atomic_read(&sp->count) == 0) ||
+ (atomic_read(&p->usage) == 0)) {
+ spin_unlock_irqrestore(&sp->siglock, flags);
+ return -ESRCH;
+ }
ret = __group_send_sig_info(sig, info, p);
spin_unlock_irqrestore(&sp->siglock, flags);
- put_task_struct(p);
}
return ret;
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to [email protected]
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
[Index of Archives]
[Kernel Newbies]
[Netfilter]
[Bugtraq]
[Photo]
[Stuff]
[Gimp]
[Yosemite News]
[MIPS Linux]
[ARM Linux]
[Linux Security]
[Linux RAID]
[Video 4 Linux]
[Linux for the blind]
[Linux Resources]
