The patch titled
wait_task_continued/zombie: don't use task_pid_nr_ns() lockless
has been removed from the -mm tree. Its filename was
wait_task_continued-zombie-dont-use-task_pid_nr_ns-lockless.patch
This patch was dropped because it was merged into mainline or a subsystem tree
The current -mm tree may be found at http://userweb.kernel.org/~akpm/mmotm/
------------------------------------------------------
Subject: wait_task_continued/zombie: don't use task_pid_nr_ns() lockless
From: Oleg Nesterov <oleg@xxxxxxxxxx>
Surprise, other 2 wait_task_() functions also abuse task_pid_nr_ns(). May
cause read-after-free or report nr == 0 in wait_task_continued().
wait_task_zombie() doesn't have this problem, but still it is better to cache
pid_t rather than call task_pid_nr_ns() 3 times on the saved pid_namespace.
Signed-off-by: Oleg Nesterov <oleg@xxxxxxxxxx>
Cc: Roland McGrath <roland@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
kernel/exit.c | 15 +++++----------
1 file changed, 5 insertions(+), 10 deletions(-)
diff -puN kernel/exit.c~wait_task_continued-zombie-dont-use-task_pid_nr_ns-lockless kernel/exit.c
--- a/kernel/exit.c~wait_task_continued-zombie-dont-use-task_pid_nr_ns-lockless
+++ a/kernel/exit.c
@@ -1189,12 +1189,9 @@ static int wait_task_zombie(struct task_
{
unsigned long state;
int retval, status, traced;
- struct pid_namespace *ns;
-
- ns = current->nsproxy->pid_ns;
+ pid_t pid = task_pid_nr_ns(p, current->nsproxy->pid_ns);
if (unlikely(noreap)) {
- pid_t pid = task_pid_nr_ns(p, ns);
uid_t uid = p->uid;
int exit_code = p->exit_code;
int why, status;
@@ -1313,11 +1310,11 @@ static int wait_task_zombie(struct task_
retval = put_user(status, &infop->si_status);
}
if (!retval && infop)
- retval = put_user(task_pid_nr_ns(p, ns), &infop->si_pid);
+ retval = put_user(pid, &infop->si_pid);
if (!retval && infop)
retval = put_user(p->uid, &infop->si_uid);
if (!retval)
- retval = task_pid_nr_ns(p, ns);
+ retval = pid;
if (traced) {
write_lock_irq(&tasklist_lock);
@@ -1436,7 +1433,6 @@ static int wait_task_continued(struct ta
int retval;
pid_t pid;
uid_t uid;
- struct pid_namespace *ns;
if (!(p->signal->flags & SIGNAL_STOP_CONTINUED))
return 0;
@@ -1451,8 +1447,7 @@ static int wait_task_continued(struct ta
p->signal->flags &= ~SIGNAL_STOP_CONTINUED;
spin_unlock_irq(&p->sighand->siglock);
- ns = current->nsproxy->pid_ns;
- pid = task_pid_nr_ns(p, ns);
+ pid = task_pid_nr_ns(p, current->nsproxy->pid_ns);
uid = p->uid;
get_task_struct(p);
read_unlock(&tasklist_lock);
@@ -1463,7 +1458,7 @@ static int wait_task_continued(struct ta
if (!retval && stat_addr)
retval = put_user(0xffff, stat_addr);
if (!retval)
- retval = task_pid_nr_ns(p, ns);
+ retval = pid;
} else {
retval = wait_noreap_copyout(p, pid, uid,
CLD_CONTINUED, SIGCONT,
_
Patches currently in -mm which might be from oleg@xxxxxxxxxx are
origin.patch
revert-proc-fix-the-threaded-proc-self.patch
procfs-task-exe-symlink.patch
procfs-task-exe-symlink-fix.patch
-
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