The patch titled
taskstats_tgid_free: fix usage
has been removed from the -mm tree. Its filename was
taskstats_tgid_free-fix-usage.patch
This patch was dropped because it was merged into mainline or a subsystem tree
------------------------------------------------------
Subject: taskstats_tgid_free: fix usage
From: Oleg Nesterov <oleg@xxxxxxxxxx>
taskstats_tgid_free() is called on copy_process's error path. This is wrong.
IF (clone_flags & CLONE_THREAD)
We should not clear ->signal->taskstats, current uses it,
it probably has a valid accumulated info.
ELSE
taskstats_tgid_init() set ->signal->taskstats = NULL,
there is nothing to free.
Move the callsite to __exit_signal(). We don't need any locking, entire
thread group is exiting, nobody should have a reference to soon to be
released ->signal.
Signed-off-by: Oleg Nesterov <oleg@xxxxxxxxxx>
Cc: Shailabh Nagar <nagar@xxxxxxxxxxxxxx>
Cc: Balbir Singh <balbir@xxxxxxxxxx>
Cc: Jay Lan <jlan@xxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxx>
---
include/linux/taskstats_kern.h | 13 ++-----------
kernel/exit.c | 1 +
kernel/fork.c | 1 -
3 files changed, 3 insertions(+), 12 deletions(-)
diff -puN include/linux/taskstats_kern.h~taskstats_tgid_free-fix-usage include/linux/taskstats_kern.h
--- a/include/linux/taskstats_kern.h~taskstats_tgid_free-fix-usage
+++ a/include/linux/taskstats_kern.h
@@ -49,17 +49,8 @@ static inline void taskstats_tgid_alloc(
static inline void taskstats_tgid_free(struct signal_struct *sig)
{
- struct taskstats *stats = NULL;
- unsigned long flags;
-
- spin_lock_irqsave(&sig->stats_lock, flags);
- if (sig->stats) {
- stats = sig->stats;
- sig->stats = NULL;
- }
- spin_unlock_irqrestore(&sig->stats_lock, flags);
- if (stats)
- kmem_cache_free(taskstats_cache, stats);
+ if (sig->stats)
+ kmem_cache_free(taskstats_cache, sig->stats);
}
extern void taskstats_exit_alloc(struct taskstats **, unsigned int *);
diff -puN kernel/exit.c~taskstats_tgid_free-fix-usage kernel/exit.c
--- a/kernel/exit.c~taskstats_tgid_free-fix-usage
+++ a/kernel/exit.c
@@ -128,6 +128,7 @@ static void __exit_signal(struct task_st
flush_sigqueue(&tsk->pending);
if (sig) {
flush_sigqueue(&sig->shared_pending);
+ taskstats_tgid_free(sig);
__cleanup_signal(sig);
}
}
diff -puN kernel/fork.c~taskstats_tgid_free-fix-usage kernel/fork.c
--- a/kernel/fork.c~taskstats_tgid_free-fix-usage
+++ a/kernel/fork.c
@@ -897,7 +897,6 @@ static inline int copy_signal(unsigned l
void __cleanup_signal(struct signal_struct *sig)
{
exit_thread_group_keys(sig);
- taskstats_tgid_free(sig);
kmem_cache_free(signal_cachep, sig);
}
_
Patches currently in -mm which might be from oleg@xxxxxxxxxx are
origin.patch
tty-signal-tty-locking.patch
do_task_stat-dont-take-tty_mutex.patch
do_acct_process-dont-take-tty_mutex.patch
trivial-make-set_special_pids-static.patch
sys_unshare-remove-a-broken-clone_sighand-code.patch
sys_setpgid-eliminate-unnecessary-do_each_task_pidpidtype_pgid.patch
session_of_pgrp-kill-unnecessary-do_each_task_pidpidtype_pgid.patch
pidhash-temporary-debug-checks.patch
-
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