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job control: Add @for_ptrace to do_notify_parent_cldstop()

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Currently, do_notify_parent_cldstop() determines whether the
notification is for the real parent or ptracer.  Move the decision to
the caller by adding @for_ptrace parameter to
do_notify_parent_cldstop().  All the callers are updated to pass
task_ptrace(target_task), so this patch doesn't cause any behavior
difference.

While at it, add function comment to do_notify_parent_cldstop().

Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Oleg Nesterov <oleg@redhat.com>
This commit is contained in:
Tejun Heo
2011-03-23 10:37:01 +01:00
parent 45cb24a1da
commit 75b95953a5
1 changed files with 24 additions and 7 deletions
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31
kernel/signal.c
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@@ -1595,16 +1595,30 @@ int do_notify_parent(struct task_struct *tsk, int sig)
return ret; return ret;
} }
static void do_notify_parent_cldstop(struct task_struct *tsk, int why) /**
* do_notify_parent_cldstop - notify parent of stopped/continued state change
* @tsk: task reporting the state change
* @for_ptracer: the notification is for ptracer
* @why: CLD_{CONTINUED|STOPPED|TRAPPED} to report
*
* Notify @tsk's parent that the stopped/continued state has changed. If
* @for_ptracer is %false, @tsk's group leader notifies to its real parent.
* If %true, @tsk reports to @tsk->parent which should be the ptracer.
*
* CONTEXT:
* Must be called with tasklist_lock at least read locked.
*/
static void do_notify_parent_cldstop(struct task_struct *tsk,
bool for_ptracer, int why)
{ {
struct siginfo info; struct siginfo info;
unsigned long flags; unsigned long flags;
struct task_struct *parent; struct task_struct *parent;
struct sighand_struct *sighand; struct sighand_struct *sighand;
if (task_ptrace(tsk)) if (for_ptracer) {
parent = tsk->parent; parent = tsk->parent;
else { } else {
tsk = tsk->group_leader; tsk = tsk->group_leader;
parent = tsk->real_parent; parent = tsk->real_parent;
} }
@@ -1743,7 +1757,7 @@ static void ptrace_stop(int exit_code, int why, int clear_code, siginfo_t *info)
spin_unlock_irq(&current->sighand->siglock); spin_unlock_irq(&current->sighand->siglock);
read_lock(&tasklist_lock); read_lock(&tasklist_lock);
if (may_ptrace_stop()) { if (may_ptrace_stop()) {
do_notify_parent_cldstop(current, why); do_notify_parent_cldstop(current, task_ptrace(current), why);
/* /*
* Don't want to allow preemption here, because * Don't want to allow preemption here, because
* sys_ptrace() needs this task to be inactive. * sys_ptrace() needs this task to be inactive.
@@ -1886,7 +1900,8 @@ retry:
if (notify) { if (notify) {
read_lock(&tasklist_lock); read_lock(&tasklist_lock);
do_notify_parent_cldstop(current, notify); do_notify_parent_cldstop(current, task_ptrace(current),
notify);
read_unlock(&tasklist_lock); read_unlock(&tasklist_lock);
} }
@@ -1982,6 +1997,7 @@ relock:
* the CLD_ si_code into SIGNAL_CLD_MASK bits. * the CLD_ si_code into SIGNAL_CLD_MASK bits.
*/ */
if (unlikely(signal->flags & SIGNAL_CLD_MASK)) { if (unlikely(signal->flags & SIGNAL_CLD_MASK)) {
struct task_struct *leader;
int why; int why;
if (signal->flags & SIGNAL_CLD_CONTINUED) if (signal->flags & SIGNAL_CLD_CONTINUED)
@@ -1994,7 +2010,8 @@ relock:
spin_unlock_irq(&sighand->siglock); spin_unlock_irq(&sighand->siglock);
read_lock(&tasklist_lock); read_lock(&tasklist_lock);
do_notify_parent_cldstop(current->group_leader, why); leader = current->group_leader;
do_notify_parent_cldstop(leader, task_ptrace(leader), why);
read_unlock(&tasklist_lock); read_unlock(&tasklist_lock);
goto relock; goto relock;
} }
@@ -2167,7 +2184,7 @@ out:
if (unlikely(group_stop)) { if (unlikely(group_stop)) {
read_lock(&tasklist_lock); read_lock(&tasklist_lock);
do_notify_parent_cldstop(tsk, group_stop); do_notify_parent_cldstop(tsk, task_ptrace(tsk), group_stop);
read_unlock(&tasklist_lock); read_unlock(&tasklist_lock);
} }
} }