From 755e276b3326f300585435d2f3876e66e248c476 Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Thu, 2 Jun 2011 11:13:59 +0200 Subject: ptrace: ptrace_check_attach(): rename @kill to @ignore_state and add comments PTRACE_INTERRUPT is going to be added which should also skip task_is_traced() check in ptrace_check_attach(). Rename @kill to @ignore_state and make it bool. Add function comment while at it. This patch doesn't introduce any behavior difference. Signed-off-by: Tejun Heo Signed-off-by: Oleg Nesterov --- kernel/ptrace.c | 24 +++++++++++++++++++----- 1 file changed, 19 insertions(+), 5 deletions(-) (limited to 'kernel/ptrace.c') diff --git a/kernel/ptrace.c b/kernel/ptrace.c index 134f34cb142b..eb191116edf7 100644 --- a/kernel/ptrace.c +++ b/kernel/ptrace.c @@ -97,10 +97,24 @@ void __ptrace_unlink(struct task_struct *child) spin_unlock(&child->sighand->siglock); } -/* - * Check that we have indeed attached to the thing.. +/** + * ptrace_check_attach - check whether ptracee is ready for ptrace operation + * @child: ptracee to check for + * @ignore_state: don't check whether @child is currently %TASK_TRACED + * + * Check whether @child is being ptraced by %current and ready for further + * ptrace operations. If @ignore_state is %false, @child also should be in + * %TASK_TRACED state and on return the child is guaranteed to be traced + * and not executing. If @ignore_state is %true, @child can be in any + * state. + * + * CONTEXT: + * Grabs and releases tasklist_lock and @child->sighand->siglock. + * + * RETURNS: + * 0 on success, -ESRCH if %child is not ready. */ -int ptrace_check_attach(struct task_struct *child, int kill) +int ptrace_check_attach(struct task_struct *child, bool ignore_state) { int ret = -ESRCH; @@ -119,13 +133,13 @@ int ptrace_check_attach(struct task_struct *child, int kill) */ spin_lock_irq(&child->sighand->siglock); WARN_ON_ONCE(task_is_stopped(child)); - if (task_is_traced(child) || kill) + if (task_is_traced(child) || ignore_state) ret = 0; spin_unlock_irq(&child->sighand->siglock); } read_unlock(&tasklist_lock); - if (!ret && !kill) + if (!ret && !ignore_state) ret = wait_task_inactive(child, TASK_TRACED) ? 0 : -ESRCH; /* All systems go.. */ -- cgit v1.2.3-58-ga151