From ed585a651681e822089087b426e6ebfb6d3d9873 Mon Sep 17 00:00:00 2001 From: Geert Uytterhoeven Date: Sun, 11 Sep 2011 13:59:27 +0200 Subject: genirq: Make irq_shutdown() symmetric vs. irq_startup again If an irq_chip provides .irq_shutdown(), but neither of .irq_disable() or .irq_mask(), free_irq() crashes when jumping to NULL. Fix this by only trying .irq_disable() and .irq_mask() if there's no .irq_shutdown() provided. This revives the symmetry with irq_startup(), which tries .irq_startup(), .irq_enable(), and irq_unmask(), and makes it consistent with the comment for irq_chip.irq_shutdown() in , which says: * @irq_shutdown: shut down the interrupt (defaults to ->disable if NULL) This is also how __free_irq() behaved before the big overhaul, cfr. e.g. 3b56f0585fd4c02d047dc406668cb40159b2d340 ("genirq: Remove bogus conditional"), where the core interrupt code always overrode .irq_shutdown() to .irq_disable() if .irq_shutdown() was NULL. Signed-off-by: Geert Uytterhoeven Cc: linux-m68k@lists.linux-m68k.org Link: http://lkml.kernel.org/r/1315742394-16036-2-git-send-email-geert@linux-m68k.org Cc: stable@kernel.org Signed-off-by: Thomas Gleixner --- kernel/irq/chip.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'kernel') diff --git a/kernel/irq/chip.c b/kernel/irq/chip.c index d5a3009da71a..dc5114b4c16c 100644 --- a/kernel/irq/chip.c +++ b/kernel/irq/chip.c @@ -178,7 +178,7 @@ void irq_shutdown(struct irq_desc *desc) desc->depth = 1; if (desc->irq_data.chip->irq_shutdown) desc->irq_data.chip->irq_shutdown(&desc->irq_data); - if (desc->irq_data.chip->irq_disable) + else if (desc->irq_data.chip->irq_disable) desc->irq_data.chip->irq_disable(&desc->irq_data); else desc->irq_data.chip->irq_mask(&desc->irq_data); -- cgit v1.2.3 From fa2563e41c3d6d6e8af437643981ed28ae0cb56d Mon Sep 17 00:00:00 2001 From: Thomas Tuttle Date: Wed, 14 Sep 2011 16:22:28 -0700 Subject: workqueue: lock cwq access in drain_workqueue Take cwq->gcwq->lock to avoid racing between drain_workqueue checking to make sure the workqueues are empty and cwq_dec_nr_in_flight decrementing and then incrementing nr_active when it activates a delayed work. We discovered this when a corner case in one of our drivers resulted in us trying to destroy a workqueue in which the remaining work would always requeue itself again in the same workqueue. We would hit this race condition and trip the BUG_ON on workqueue.c:3080. Signed-off-by: Thomas Tuttle Acked-by: Tejun Heo Cc: Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- kernel/workqueue.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) (limited to 'kernel') diff --git a/kernel/workqueue.c b/kernel/workqueue.c index 25fb1b0e53fa..1783aabc6128 100644 --- a/kernel/workqueue.c +++ b/kernel/workqueue.c @@ -2412,8 +2412,13 @@ reflush: for_each_cwq_cpu(cpu, wq) { struct cpu_workqueue_struct *cwq = get_cwq(cpu, wq); + bool drained; - if (!cwq->nr_active && list_empty(&cwq->delayed_works)) + spin_lock_irq(&cwq->gcwq->lock); + drained = !cwq->nr_active && list_empty(&cwq->delayed_works); + spin_unlock_irq(&cwq->gcwq->lock); + + if (drained) continue; if (++flush_cnt == 10 || -- cgit v1.2.3 From 1a51410abe7d0ee4b1d112780f46df87d3621043 Mon Sep 17 00:00:00 2001 From: Linus Torvalds Date: Mon, 19 Sep 2011 17:04:37 -0700 Subject: Make TASKSTATS require root access Ok, this isn't optimal, since it means that 'iotop' needs admin capabilities, and we may have to work on this some more. But at the same time it is very much not acceptable to let anybody just read anybody elses IO statistics quite at this level. Use of the GENL_ADMIN_PERM suggested by Johannes Berg as an alternative to checking the capabilities by hand. Reported-by: Vasiliy Kulikov Cc: Johannes Berg Acked-by: Balbir Singh Signed-off-by: Linus Torvalds --- kernel/taskstats.c | 1 + 1 file changed, 1 insertion(+) (limited to 'kernel') diff --git a/kernel/taskstats.c b/kernel/taskstats.c index e19ce1454ee1..e66046456f4f 100644 --- a/kernel/taskstats.c +++ b/kernel/taskstats.c @@ -655,6 +655,7 @@ static struct genl_ops taskstats_ops = { .cmd = TASKSTATS_CMD_GET, .doit = taskstats_user_cmd, .policy = taskstats_cmd_get_policy, + .flags = GENL_ADMIN_PERM, }; static struct genl_ops cgroupstats_ops = { -- cgit v1.2.3 From 58c3c3aa01b455ecb99d61ce73f1444274af696b Mon Sep 17 00:00:00 2001 From: Linus Torvalds Date: Mon, 19 Sep 2011 17:10:57 -0700 Subject: Make taskstats round statistics down to nearest 1k bytes/events Even with just the interface limited to admin, there really is little to reason to give byte-per-byte counts for taskstats. So round it down to something less intrusive. Acked-by: Balbir Singh Signed-off-by: Linus Torvalds --- kernel/tsacct.c | 15 ++++++++------- 1 file changed, 8 insertions(+), 7 deletions(-) (limited to 'kernel') diff --git a/kernel/tsacct.c b/kernel/tsacct.c index 24dc60d9fa1f..5bbfac85866e 100644 --- a/kernel/tsacct.c +++ b/kernel/tsacct.c @@ -78,6 +78,7 @@ void bacct_add_tsk(struct taskstats *stats, struct task_struct *tsk) #define KB 1024 #define MB (1024*KB) +#define KB_MASK (~(KB-1)) /* * fill in extended accounting fields */ @@ -95,14 +96,14 @@ void xacct_add_tsk(struct taskstats *stats, struct task_struct *p) stats->hiwater_vm = get_mm_hiwater_vm(mm) * PAGE_SIZE / KB; mmput(mm); } - stats->read_char = p->ioac.rchar; - stats->write_char = p->ioac.wchar; - stats->read_syscalls = p->ioac.syscr; - stats->write_syscalls = p->ioac.syscw; + stats->read_char = p->ioac.rchar & KB_MASK; + stats->write_char = p->ioac.wchar & KB_MASK; + stats->read_syscalls = p->ioac.syscr & KB_MASK; + stats->write_syscalls = p->ioac.syscw & KB_MASK; #ifdef CONFIG_TASK_IO_ACCOUNTING - stats->read_bytes = p->ioac.read_bytes; - stats->write_bytes = p->ioac.write_bytes; - stats->cancelled_write_bytes = p->ioac.cancelled_write_bytes; + stats->read_bytes = p->ioac.read_bytes & KB_MASK; + stats->write_bytes = p->ioac.write_bytes & KB_MASK; + stats->cancelled_write_bytes = p->ioac.cancelled_write_bytes & KB_MASK; #else stats->read_bytes = 0; stats->write_bytes = 0; -- cgit v1.2.3