From e0e8eb54d8ae0c4cfd1d297f6351b08a7f635c5f Mon Sep 17 00:00:00 2001 From: "Eric W. Biederman" Date: Thu, 16 Mar 2006 10:31:38 -0700 Subject: [PATCH] unshare: Use rcu_assign_pointer when setting sighand The sighand pointer only needs the rcu_read_lock on the read side. So only depending on task_lock protection when setting this pointer is not enough. We also need a memory barrier to ensure the initialization is seen first. Use rcu_assign_pointer as it does this for us, and clearly documents that we are setting an rcu readable pointer. Signed-off-by: Eric W. Biederman Acked-by: Paul E. McKenney Signed-off-by: Linus Torvalds --- kernel/fork.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'kernel') diff --git a/kernel/fork.c b/kernel/fork.c index ccdfbb16c86..46060cb24af 100644 --- a/kernel/fork.c +++ b/kernel/fork.c @@ -1569,7 +1569,7 @@ asmlinkage long sys_unshare(unsigned long unshare_flags) if (new_sigh) { sigh = current->sighand; - current->sighand = new_sigh; + rcu_assign_pointer(current->sighand, new_sigh); new_sigh = sigh; } -- cgit v1.2.3-70-g09d2 From 67890d7084085e29c51afa2514036d42643fd3cf Mon Sep 17 00:00:00 2001 From: Christoph Lameter Date: Thu, 16 Mar 2006 23:04:00 -0800 Subject: [PATCH] time_interpolator: add __read_mostly The pointer to the current time interpolator and the current list of time interpolators are typically only changed during bootup. Adding __read_mostly takes them away from possibly hot cachelines. Signed-off-by: Christoph Lameter Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- kernel/timer.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'kernel') diff --git a/kernel/timer.c b/kernel/timer.c index bf7c4193b93..2410c18dbeb 100644 --- a/kernel/timer.c +++ b/kernel/timer.c @@ -1354,8 +1354,8 @@ void __init init_timers(void) #ifdef CONFIG_TIME_INTERPOLATION -struct time_interpolator *time_interpolator; -static struct time_interpolator *time_interpolator_list; +struct time_interpolator *time_interpolator __read_mostly; +static struct time_interpolator *time_interpolator_list __read_mostly; static DEFINE_SPINLOCK(time_interpolator_lock); static inline u64 time_interpolator_get_cycles(unsigned int src) -- cgit v1.2.3-70-g09d2 From a0a0c28c1a7109d7955815074c52cac079ab3ba5 Mon Sep 17 00:00:00 2001 From: Roman Zippel Date: Thu, 16 Mar 2006 23:04:01 -0800 Subject: [PATCH] posix-timers: fix requeue accounting when signal is ignored When the posix-timer signal is ignored then the timer is rearmed by the callback function. The requeue pending accounting has to be fixed up else the state might be wrong. Signed-off-by: Roman Zippel Signed-off-by: Thomas Gleixner Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- kernel/posix-timers.c | 1 + 1 file changed, 1 insertion(+) (limited to 'kernel') diff --git a/kernel/posix-timers.c b/kernel/posix-timers.c index 216f574b5ff..fa895fc2ecf 100644 --- a/kernel/posix-timers.c +++ b/kernel/posix-timers.c @@ -353,6 +353,7 @@ static int posix_timer_fn(void *data) hrtimer_forward(&timr->it.real.timer, timr->it.real.interval); ret = HRTIMER_RESTART; + ++timr->it_requeue_pending; } } -- cgit v1.2.3-70-g09d2 From 2d61b86775a5676a8fba2ba2f0f869564e35c630 Mon Sep 17 00:00:00 2001 From: Oleg Nesterov Date: Sat, 18 Mar 2006 20:41:10 +0300 Subject: [PATCH] disable unshare(CLONE_VM) for now sys_unshare() does mmput(new_mm). This is not enough if we have mm->core_waiters. This patch is a temporary fix for soon to be released 2.6.16. Signed-off-by: Oleg Nesterov [ Checked with Uli: "I'm not planning to use unshare(CLONE_VM). It's not needed for any functionality planned so far. What we (as in Red Hat) need unshare() for now is the filesystem side." ] Signed-off-by: Linus Torvalds --- kernel/fork.c | 4 +--- 1 file changed, 1 insertion(+), 3 deletions(-) (limited to 'kernel') diff --git a/kernel/fork.c b/kernel/fork.c index 46060cb24af..b373322ca49 100644 --- a/kernel/fork.c +++ b/kernel/fork.c @@ -1478,9 +1478,7 @@ static int unshare_vm(unsigned long unshare_flags, struct mm_struct **new_mmp) if ((unshare_flags & CLONE_VM) && (mm && atomic_read(&mm->mm_users) > 1)) { - *new_mmp = dup_mm(current); - if (!*new_mmp) - return -ENOMEM; + return -EINVAL; } return 0; -- cgit v1.2.3-70-g09d2