From a6bebbc87a8c16eabb6bd5c6fd2d994be0236fba Mon Sep 17 00:00:00 2001
From: Lai Jiangshan <laijs@cn.fujitsu.com>
Date: Sun, 5 Oct 2008 00:51:15 +0400
Subject: [PATCH] signal, procfs: some lock_task_sighand() users do not need
rcu_read_lock()
lock_task_sighand() make sure task->sighand is being protected,
so we do not need rcu_read_lock().
[ exec() will get task->sighand->siglock before change task->sighand! ]
But code using rcu_read_lock() _just_ to protect lock_task_sighand()
only appear in procfs. (and some code in procfs use lock_task_sighand()
without such redundant protection.)
Other subsystem may put lock_task_sighand() into rcu_read_lock()
critical region, but these rcu_read_lock() are used for protecting
"for_each_process()", "find_task_by_vpid()" etc. , not for protecting
lock_task_sighand().
Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com>
[ok from Oleg]
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
---
fs/proc/array.c | 2 --
1 file changed, 2 deletions(-)
(limited to 'fs/proc/array.c')
diff --git a/fs/proc/array.c b/fs/proc/array.c
index 71c9be59c9c..1c8d7b5d7a1 100644
--- a/fs/proc/array.c
+++ b/fs/proc/array.c
@@ -261,7 +261,6 @@ static inline void task_sig(struct seq_file *m, struct task_struct *p)
sigemptyset(&ignored);
sigemptyset(&caught);
- rcu_read_lock();
if (lock_task_sighand(p, &flags)) {
pending = p->pending.signal;
shpending = p->signal->shared_pending.signal;
@@ -272,7 +271,6 @@ static inline void task_sig(struct seq_file *m, struct task_struct *p)
qlim = p->signal->rlim[RLIMIT_SIGPENDING].rlim_cur;
unlock_task_sighand(p, &flags);
}
- rcu_read_unlock();
seq_printf(m, "Threads:\t%d\n", num_threads);
seq_printf(m, "SigQ:\t%lu/%lu\n", qsize, qlim);
--
cgit v1.2.3-70-g09d2
From 45acb8db06bad529f0feaf89465ce33152640089 Mon Sep 17 00:00:00 2001
From: Alexey Dobriyan <adobriyan@gmail.com>
Date: Tue, 7 Oct 2008 01:58:45 +0400
Subject: proc: remove now unneeded ADDBUF macro
After local seq_file conversion it was forgotten.
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
---
fs/proc/array.c | 5 -----
1 file changed, 5 deletions(-)
(limited to 'fs/proc/array.c')
diff --git a/fs/proc/array.c b/fs/proc/array.c
index 1c8d7b5d7a1..f4bc0e78953 100644
--- a/fs/proc/array.c
+++ b/fs/proc/array.c
@@ -86,11 +86,6 @@
#include <asm/processor.h>
#include "internal.h"
-/* Gcc optimizes away "strlen(x)" for constant x */
-#define ADDBUF(buffer, string) \
-do { memcpy(buffer, string, strlen(string)); \
- buffer += strlen(string); } while (0)
-
static inline void task_name(struct seq_file *m, struct task_struct *p)
{
int i;
--
cgit v1.2.3-70-g09d2