| lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC | |
|
Open Source and information security mailing list archives
| ||
|
Message-ID: <20061026232203.GA532@oleg>
Date: Fri, 27 Oct 2006 03:22:03 +0400
From: Oleg Nesterov <oleg@...sign.ru>
To: Andrew Morton <akpm@...l.org>
Cc: Shailabh Nagar <nagar@...son.ibm.com>,
Balbir Singh <balbir@...ibm.com>, Jay Lan <jlan@....com>,
linux-kernel@...r.kernel.org
Subject: [PATCH 5/6] taskstats: kill ->taskstats_lock in favor of ->siglock
signal_struct is (mostly) protected by ->sighand->siglock, I think
we don't need ->taskstats_lock to protect ->stats. This also allows
us to simplify the locking in fill_tgid().
Signed-off-by: Oleg Nesterov <oleg@...sign.ru>
include/linux/sched.h | 1 -
include/linux/taskstats_kern.h | 15 ++++++---------
kernel/fork.c | 2 +-
kernel/taskstats.c | 16 ++++++----------
4 files changed, 13 insertions(+), 21 deletions(-)
--- STATS/include/linux/sched.h~5_siglock 2006-10-22 18:24:18.000000000 +0400
+++ STATS/include/linux/sched.h 2006-10-27 01:49:19.000000000 +0400
@@ -466,7 +466,6 @@ struct signal_struct {
struct pacct_struct pacct; /* per-process accounting information */
#endif
#ifdef CONFIG_TASKSTATS
- spinlock_t stats_lock;
struct taskstats *stats;
#endif
};
--- STATS/include/linux/taskstats_kern.h~5_siglock 2006-10-27 01:39:10.000000000 +0400
+++ STATS/include/linux/taskstats_kern.h 2006-10-27 02:13:11.000000000 +0400
@@ -23,28 +23,26 @@ static inline void taskstats_exit_free(s
static inline void taskstats_tgid_init(struct signal_struct *sig)
{
- spin_lock_init(&sig->stats_lock);
sig->stats = NULL;
}
-static inline void taskstats_tgid_alloc(struct signal_struct *sig)
+static inline void taskstats_tgid_alloc(struct task_struct *tsk)
{
+ struct signal_struct *sig = tsk->signal;
struct taskstats *stats;
- unsigned long flags;
if (sig->stats != NULL)
return;
+ /* No problem if kmem_cache_zalloc() fails */
stats = kmem_cache_zalloc(taskstats_cache, SLAB_KERNEL);
- if (!stats)
- return;
- spin_lock_irqsave(&sig->stats_lock, flags);
+ spin_lock_irq(&tsk->sighand->siglock);
if (!sig->stats) {
sig->stats = stats;
stats = NULL;
}
- spin_unlock_irqrestore(&sig->stats_lock, flags);
+ spin_unlock_irq(&tsk->sighand->siglock);
if (stats)
kmem_cache_free(taskstats_cache, stats);
@@ -59,7 +57,6 @@ static inline void taskstats_tgid_free(s
extern void taskstats_exit_alloc(struct taskstats **, unsigned int *);
extern void taskstats_exit_send(struct task_struct *, struct taskstats *, int, unsigned int);
extern void taskstats_init_early(void);
-extern void taskstats_tgid_alloc(struct signal_struct *);
#else
static inline void taskstats_exit_alloc(struct taskstats **ptidstats, unsigned int *mycpu)
{}
@@ -71,7 +68,7 @@ static inline void taskstats_exit_send(s
{}
static inline void taskstats_tgid_init(struct signal_struct *sig)
{}
-static inline void taskstats_tgid_alloc(struct signal_struct *sig)
+static inline void taskstats_tgid_alloc(struct task_struct *tsk)
{}
static inline void taskstats_tgid_free(struct signal_struct *sig)
{}
--- STATS/kernel/fork.c~5_siglock 2006-10-27 01:29:28.000000000 +0400
+++ STATS/kernel/fork.c 2006-10-27 02:16:30.000000000 +0400
@@ -830,7 +830,7 @@ static inline int copy_signal(unsigned l
if (clone_flags & CLONE_THREAD) {
atomic_inc(¤t->signal->count);
atomic_inc(¤t->signal->live);
- taskstats_tgid_alloc(current->signal);
+ taskstats_tgid_alloc(current);
return 0;
}
sig = kmem_cache_alloc(signal_cachep, GFP_KERNEL);
--- STATS/kernel/taskstats.c~5_siglock 2006-10-26 23:44:32.000000000 +0400
+++ STATS/kernel/taskstats.c 2006-10-27 02:00:32.000000000 +0400
@@ -241,11 +241,11 @@ static int fill_tgid(pid_t tgid, struct
tsk = first;
read_lock(&tasklist_lock);
/* Start with stats from dead tasks */
- if (first->signal) {
- spin_lock_irqsave(&first->signal->stats_lock, flags);
+ if (first->sighand) {
+ spin_lock_irqsave(&first->sighand->siglock, flags);
if (first->signal->stats)
memcpy(stats, first->signal->stats, sizeof(*stats));
- spin_unlock_irqrestore(&first->signal->stats_lock, flags);
+ spin_unlock_irqrestore(&first->sighand->siglock, flags);
}
do {
@@ -276,7 +276,7 @@ static void fill_tgid_exit(struct task_s
{
unsigned long flags;
- spin_lock_irqsave(&tsk->signal->stats_lock, flags);
+ spin_lock_irqsave(&tsk->sighand->siglock, flags);
if (!tsk->signal->stats)
goto ret;
@@ -288,7 +288,7 @@ static void fill_tgid_exit(struct task_s
*/
delayacct_add_tsk(tsk->signal->stats, tsk);
ret:
- spin_unlock_irqrestore(&tsk->signal->stats_lock, flags);
+ spin_unlock_irqrestore(&tsk->sighand->siglock, flags);
return;
}
@@ -464,15 +464,10 @@ void taskstats_exit_send(struct task_str
size_t size;
int is_thread_group;
struct nlattr *na;
- unsigned long flags;
if (!family_registered || !tidstats)
return;
- spin_lock_irqsave(&tsk->signal->stats_lock, flags);
- is_thread_group = tsk->signal->stats ? 1 : 0;
- spin_unlock_irqrestore(&tsk->signal->stats_lock, flags);
-
rc = 0;
/*
* Size includes space for nested attributes
@@ -480,6 +475,7 @@ void taskstats_exit_send(struct task_str
size = nla_total_size(sizeof(u32)) +
nla_total_size(sizeof(struct taskstats)) + nla_total_size(0);
+ is_thread_group = (tsk->signal->stats != NULL);
if (is_thread_group)
size = 2 * size; /* PID + STATS + TGID + STATS */
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
Powered by blists - more mailing lists