[PATCH 2/2] ia64: ptrace_attach_sync_user_rbs: avoid "task->signal != NULL" checks
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From: Oleg Nesterov on 18 Mar 2010 15:00 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(a)redhat.com> --- arch/ia64/kernel/ptrace.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) --- 34-rc1/arch/ia64/kernel/ptrace.c~6_IA64_DONT_CHECK_SIGNAL 2010-03-11 13:11:48.000000000 +0100 +++ 34-rc1/arch/ia64/kernel/ptrace.c 2010-03-18 19:12:45.000000000 +0100 @@ -639,7 +639,7 @@ ptrace_attach_sync_user_rbs (struct task */ 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)) { @@ -663,7 +663,7 @@ ptrace_attach_sync_user_rbs (struct task * 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)) { -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo(a)vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/ |