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| author | Tejun Heo <tj@kernel.org> | 2011-06-02 11:13:59 +0200 |
|---|---|---|
| committer | Oleg Nesterov <oleg@redhat.com> | 2011-06-04 18:17:10 +0200 |
| commit | 755e276b3326f300585435d2f3876e66e248c476 (patch) | |
| tree | 67ee93cf68a1ee0e307c0d8fcd4514a61dcdd697 /kernel | |
| parent | a8f072c1d624a627b67f2ace2f0c25d856ef4e54 (diff) | |
| download | lwn-755e276b3326f300585435d2f3876e66e248c476.tar.gz lwn-755e276b3326f300585435d2f3876e66e248c476.zip | |
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 <tj@kernel.org>
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/ptrace.c | 24 |
1 files changed, 19 insertions, 5 deletions
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.. */ |