Messages in this thread Patch in this message | | | Date | Wed, 4 Feb 2009 00:17:11 +0100 | From | Oleg Nesterov <> | Subject | [PATCH 1/2] ia64: ptrace_attach_sync_user_rbs: use ->sighand instead of ->signal to check the task is alive |
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No functional changes.
It doesn't matter which pointer to 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.
Actually, this code doesn't need tasklist_lock and this check at all, it should be converted to use lock_task_sighand().
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
--- 6.29-rc3/arch/ia64/kernel/ptrace.c~1_IA64_PTRACE 2008-12-02 17:12:35.000000000 +0100 +++ 6.29-rc3/arch/ia64/kernel/ptrace.c 2009-02-03 23:55:41.000000000 +0100 @@ -640,7 +640,7 @@ 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)) { @@ -664,7 +664,7 @@ 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)) {
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