From 83cb16727085b18191f45eb0ede6bf1f97d67a7a Mon Sep 17 00:00:00 2001 From: Ingo Molnar Date: Wed, 14 Oct 2009 17:48:38 +0200 Subject: [PATCH 1/3] nvram: Drop the BKL from nvram_open() It's safe to remove the BKL from nvram_open(): there's no open() versus read() races: nvram_init() is very simple and race-free, it registers the device then puts it into /proc - there's no state init to race with. Cc: Wim Van Sebroeck Cc: Al Viro Cc: Frederic Weisbecker Cc: Thomas Gleixner LKML-Reference: <1255116426-7270-1-git-send-email-fweisbec@gmail.com> Signed-off-by: Ingo Molnar --- drivers/char/nvram.c | 3 --- 1 file changed, 3 deletions(-) diff --git a/drivers/char/nvram.c b/drivers/char/nvram.c index 2100a8f7bd862..7cf4518c030f2 100644 --- a/drivers/char/nvram.c +++ b/drivers/char/nvram.c @@ -329,14 +329,12 @@ static int nvram_ioctl(struct inode *inode, struct file *file, static int nvram_open(struct inode *inode, struct file *file) { - lock_kernel(); spin_lock(&nvram_state_lock); if ((nvram_open_cnt && (file->f_flags & O_EXCL)) || (nvram_open_mode & NVRAM_EXCL) || ((file->f_mode & FMODE_WRITE) && (nvram_open_mode & NVRAM_WRITE))) { spin_unlock(&nvram_state_lock); - unlock_kernel(); return -EBUSY; } @@ -347,7 +345,6 @@ static int nvram_open(struct inode *inode, struct file *file) nvram_open_cnt++; spin_unlock(&nvram_state_lock); - unlock_kernel(); return 0; } From f409adf5b1db55ece7e80b67a944f9c0d3fe93e9 Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Tue, 1 Dec 2009 14:02:00 +0100 Subject: [PATCH 2/3] futex: Protect pid lookup in compat code with RCU find_task_by_vpid() in compat_sys_get_robust_list() does not require tasklist_lock. It can be protected with rcu_read_lock as done in sys_get_robust_list() already. Signed-off-by: Thomas Gleixner Cc: Darren Hart Cc: Peter Zijlstra --- kernel/futex_compat.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/kernel/futex_compat.c b/kernel/futex_compat.c index 235716556bf16..d49afb2395e5c 100644 --- a/kernel/futex_compat.c +++ b/kernel/futex_compat.c @@ -146,7 +146,7 @@ compat_sys_get_robust_list(int pid, compat_uptr_t __user *head_ptr, struct task_struct *p; ret = -ESRCH; - read_lock(&tasklist_lock); + rcu_read_lock(); p = find_task_by_vpid(pid); if (!p) goto err_unlock; @@ -157,7 +157,7 @@ compat_sys_get_robust_list(int pid, compat_uptr_t __user *head_ptr, !capable(CAP_SYS_PTRACE)) goto err_unlock; head = p->compat_robust_list; - read_unlock(&tasklist_lock); + rcu_read_unlock(); } if (put_user(sizeof(*head), len_ptr)) @@ -165,7 +165,7 @@ compat_sys_get_robust_list(int pid, compat_uptr_t __user *head_ptr, return put_user(ptr_to_compat(head), head_ptr); err_unlock: - read_unlock(&tasklist_lock); + rcu_read_unlock(); return ret; } From 599faa0e264fe2e7f563f87b4aad8c83e9dc46d1 Mon Sep 17 00:00:00 2001 From: Mark Brown Date: Tue, 5 Jan 2010 13:29:58 +0000 Subject: [PATCH 3/3] genirq: Fix documentation of default chip disable() The documentation says that by default disable() will be chip->mask but in fact default_disable() is a noop. Signed-off-by: Mark Brown LKML-Reference: <1262698198-30392-1-git-send-email-broonie@opensource.wolfsonmicro.com> Signed-off-by: Ingo Molnar --- include/linux/irq.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/include/linux/irq.h b/include/linux/irq.h index 451481c082b55..d13492df57a1b 100644 --- a/include/linux/irq.h +++ b/include/linux/irq.h @@ -90,7 +90,7 @@ struct msi_desc; * @startup: start up the interrupt (defaults to ->enable if NULL) * @shutdown: shut down the interrupt (defaults to ->disable if NULL) * @enable: enable the interrupt (defaults to chip->unmask if NULL) - * @disable: disable the interrupt (defaults to chip->mask if NULL) + * @disable: disable the interrupt * @ack: start of a new interrupt * @mask: mask an interrupt source * @mask_ack: ack and mask an interrupt source