Messages in this thread Patch in this message | | | Date | Wed, 21 Nov 2007 19:00:33 +0300 | From | Oleg Nesterov <> | Subject | [PATCH -mm 3/3] ptrace_check_attach: remove unneeded ->signal != NULL check |
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It is not possible to see the PT_PTRACED task without ->signal/sighand under tasklist_lock, release_task() does ptrace_unlink() first. If the task was already released before, ptrace_attach() can't succeed and set PT_PTRACED. Remove this check.
Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru>
--- PT/kernel/ptrace.c~3_signal 2007-11-21 16:53:39.000000000 +0300 +++ PT/kernel/ptrace.c 2007-11-21 17:20:24.000000000 +0300 @@ -99,9 +99,12 @@ int ptrace_check_attach(struct task_stru * be changed by us so it's not changing right after this. */ read_lock(&tasklist_lock); - if ((child->ptrace & PT_PTRACED) && child->parent == current && - child->signal != NULL) { + if ((child->ptrace & PT_PTRACED) && child->parent == current) { ret = 0; + /* + * child->sighand can't be NULL, release_task() + * does ptrace_unlink() before __exit_signal(). + */ spin_lock_irq(&child->sighand->siglock); if (is_task_stopped(child)) __set_task_state(child, TASK_TRACED); - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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