The patch titled
uglify while_each_pid_task() to make sure we don't count the execing pricess twice
has been removed from the -mm tree. Its filename was
uglify-while_each_pid_task-to-make-sure-we-dont-count-the-execing-pricess-twice.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: uglify while_each_pid_task() to make sure we don't count the execing pricess twice
From: Oleg Nesterov <oleg@xxxxxxxxxx>
There is a window when de_thread() switches the leader and drops
tasklist_lock. In that window do_each_pid_task(PIDTYPE_PID) finds both new
and old leaders.
The problem is pretty much theoretical and probably can be ignored. Currently
the only users of do_each_pid_task(PIDTYPE_PID) are send_sigio/send_sigurg, so
they can send the signal to the same process twice.
Signed-off-by: Oleg Nesterov <oleg@xxxxxxxxxx>
Cc: "Eric W. Biederman" <ebiederm@xxxxxxxxxxxx>
Cc: Davide Libenzi <davidel@xxxxxxxxxxxxxxx>
Cc: Pavel Emelyanov <xemul@xxxxxxxxxx>
Cc: Roland McGrath <roland@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
include/linux/pid.h | 6 ++++++
1 file changed, 6 insertions(+)
diff -puN include/linux/pid.h~uglify-while_each_pid_task-to-make-sure-we-dont-count-the-execing-pricess-twice include/linux/pid.h
--- a/include/linux/pid.h~uglify-while_each_pid_task-to-make-sure-we-dont-count-the-execing-pricess-twice
+++ a/include/linux/pid.h
@@ -152,7 +152,13 @@ pid_t pid_vnr(struct pid *pid);
hlist_for_each_entry_rcu((task), pos___, \
&pid->tasks[type], pids[type].node) {
+ /*
+ * Both old and new leaders may be attached to
+ * the same pid in the middle of de_thread().
+ */
#define while_each_pid_task(pid, type, task) \
+ if (type == PIDTYPE_PID) \
+ break; \
} \
} while (0)
_
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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