ptrace: don't take tasklist to get/set ->last_siginfo

Change ptrace_getsiginfo/ptrace_setsiginfo to use lock_task_sighand()
without tasklist_lock.  Perhaps it makes sense to make a single helper
with "bool rw" argument.

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Roland McGrath <roland@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Oleg Nesterov 2009-06-17 16:27:36 -07:00 committed by Linus Torvalds
parent d92656633b
commit e49612544c

View file

@ -424,37 +424,33 @@ static int ptrace_setoptions(struct task_struct *child, long data)
static int ptrace_getsiginfo(struct task_struct *child, siginfo_t *info)
{
unsigned long flags;
int error = -ESRCH;
read_lock(&tasklist_lock);
if (likely(child->sighand != NULL)) {
if (lock_task_sighand(child, &flags)) {
error = -EINVAL;
spin_lock_irq(&child->sighand->siglock);
if (likely(child->last_siginfo != NULL)) {
*info = *child->last_siginfo;
error = 0;
}
spin_unlock_irq(&child->sighand->siglock);
unlock_task_sighand(child, &flags);
}
read_unlock(&tasklist_lock);
return error;
}
static int ptrace_setsiginfo(struct task_struct *child, const siginfo_t *info)
{
unsigned long flags;
int error = -ESRCH;
read_lock(&tasklist_lock);
if (likely(child->sighand != NULL)) {
if (lock_task_sighand(child, &flags)) {
error = -EINVAL;
spin_lock_irq(&child->sighand->siglock);
if (likely(child->last_siginfo != NULL)) {
*child->last_siginfo = *info;
error = 0;
}
spin_unlock_irq(&child->sighand->siglock);
unlock_task_sighand(child, &flags);
}
read_unlock(&tasklist_lock);
return error;
}