ia64: ptrace_attach_sync_user_rbs: avoid "task->signal != NULL" checks
Preparation to make task->signal immutable, no functional changes.
It doesn't matter which pointer we check under tasklist to ensure the task
was not released, ->signal or ->sighand. But we are going to make
->signal refcountable, change the code to use ->sighand.
Note: this code doesn't need this check and tasklist_lock at all, it
should be converted to use lock_task_sighand(). And, the code under
SIGNAL_STOP_STOPPED check looks wrong.
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: Roland McGrath <roland@redhat.com>
Cc: Stanislaw Gruszka <sgruszka@redhat.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/arch/ia64/kernel/ptrace.c b/arch/ia64/kernel/ptrace.c
index 0dec7f7..7c7909f 100644
--- a/arch/ia64/kernel/ptrace.c
+++ b/arch/ia64/kernel/ptrace.c
@@ -638,7 +638,7 @@
*/
read_lock(&tasklist_lock);
- if (child->signal) {
+ if (child->sighand) {
spin_lock_irq(&child->sighand->siglock);
if (child->state == TASK_STOPPED &&
!test_and_set_tsk_thread_flag(child, TIF_RESTORE_RSE)) {
@@ -662,7 +662,7 @@
* job control stop, so that SIGCONT can be used to wake it up.
*/
read_lock(&tasklist_lock);
- if (child->signal) {
+ if (child->sighand) {
spin_lock_irq(&child->sighand->siglock);
if (child->state == TASK_TRACED &&
(child->signal->flags & SIGNAL_STOP_STOPPED)) {