From bce61dd49d6ba7799be2de17c772e4c701558f14 Mon Sep 17 00:00:00 2001 From: Ben Collins Date: Mon, 28 Nov 2005 13:43:56 -0800 Subject: [PATCH] [PATCH] Fix hardcoded cpu=0 in workqueue for per_cpu_ptr() calls Tracked this down on an Ultra Enterprise 3000. It's a 6-way machine. Odd thing about this machine (and it's good for finding bugs like this) is that the CPU id's are not 0 based. For instance, on my machine the CPU's are 6/7/10/11/14/15. This caused some NULL pointer dereference in kernel/workqueue.c because for single_threaded workqueue's, it hardcoded the cpu to 0. I changed the 0's to any_online_cpu(cpu_online_mask), which cpumask.h claims is "First cpu in mask". So this fits the same usage. Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- kernel/workqueue.c | 12 ++++++------ 1 file changed, 6 insertions(+), 6 deletions(-) diff --git a/kernel/workqueue.c b/kernel/workqueue.c index 42df83d7fad..2bd5aee1c73 100644 --- a/kernel/workqueue.c +++ b/kernel/workqueue.c @@ -102,7 +102,7 @@ int fastcall queue_work(struct workqueue_struct *wq, struct work_struct *work) if (!test_and_set_bit(0, &work->pending)) { if (unlikely(is_single_threaded(wq))) - cpu = 0; + cpu = any_online_cpu(cpu_online_map); BUG_ON(!list_empty(&work->entry)); __queue_work(per_cpu_ptr(wq->cpu_wq, cpu), work); ret = 1; @@ -118,7 +118,7 @@ static void delayed_work_timer_fn(unsigned long __data) int cpu = smp_processor_id(); if (unlikely(is_single_threaded(wq))) - cpu = 0; + cpu = any_online_cpu(cpu_online_map); __queue_work(per_cpu_ptr(wq->cpu_wq, cpu), work); } @@ -266,8 +266,8 @@ void fastcall flush_workqueue(struct workqueue_struct *wq) might_sleep(); if (is_single_threaded(wq)) { - /* Always use cpu 0's area. */ - flush_cpu_workqueue(per_cpu_ptr(wq->cpu_wq, 0)); + /* Always use first cpu's area. */ + flush_cpu_workqueue(per_cpu_ptr(wq->cpu_wq, any_online_cpu(cpu_online_map))); } else { int cpu; @@ -320,7 +320,7 @@ struct workqueue_struct *__create_workqueue(const char *name, lock_cpu_hotplug(); if (singlethread) { INIT_LIST_HEAD(&wq->list); - p = create_workqueue_thread(wq, 0); + p = create_workqueue_thread(wq, any_online_cpu(cpu_online_map)); if (!p) destroy = 1; else @@ -374,7 +374,7 @@ void destroy_workqueue(struct workqueue_struct *wq) /* We don't need the distraction of CPUs appearing and vanishing. */ lock_cpu_hotplug(); if (is_single_threaded(wq)) - cleanup_workqueue_thread(wq, 0); + cleanup_workqueue_thread(wq, any_online_cpu(cpu_online_map)); else { for_each_online_cpu(cpu) cleanup_workqueue_thread(wq, cpu); -- 2.41.1