Messages in this thread Patch in this message | | | Date | Mon, 25 Dec 2006 17:12:57 +0900 | From | Akinobu Mita <> | Subject | [PATCH -mm] ehca: avoid crash on kthread_create() failure |
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On Thu, Dec 21, 2006 at 10:22:02PM +0100, Heiko Carstens wrote: > > Index: 2.6-mm/drivers/infiniband/hw/ehca/ehca_irq.c > > =================================================================== > > --- 2.6-mm.orig/drivers/infiniband/hw/ehca/ehca_irq.c > > +++ 2.6-mm/drivers/infiniband/hw/ehca/ehca_irq.c > > @@ -670,11 +670,13 @@ static int comp_pool_callback(struct not > > { > > unsigned int cpu = (unsigned long)hcpu; > > struct ehca_cpu_comp_task *cct; > > + struct task_struct *task; > > > > switch (action) { > > case CPU_UP_PREPARE: > > ehca_gen_dbg("CPU: %x (CPU_PREPARE)", cpu); > > - if(!create_comp_task(pool, cpu)) { > > + task = create_comp_task(pool, cpu); > > + if (IS_ERR(task)) { > > ehca_gen_err("Can't create comp_task for cpu: %x", cpu); > > return NOTIFY_BAD; > > } > > If this fails then the code will crash on CPU_UP_CANCELED. Because of > kthread_bind(cct->task,...). cct->task would be just the encoded error > number.
Subject: [PATCH -mm] ehca: avoid crash on kthread_create() failure
This patch disallows invalid task_struct pointer returned by kthread_create() to be written to percpu data to avoid crash.
Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Hoang-Nam Nguyen <hnguyen@de.ibm.com> Cc: Christoph Raisch <raisch@de.ibm.com> Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
--- drivers/infiniband/hw/ehca/ehca_irq.c | 11 ++++++++--- 1 file changed, 8 insertions(+), 3 deletions(-)
Index: 2.6-mm/drivers/infiniband/hw/ehca/ehca_irq.c =================================================================== --- 2.6-mm.orig/drivers/infiniband/hw/ehca/ehca_irq.c +++ 2.6-mm/drivers/infiniband/hw/ehca/ehca_irq.c @@ -606,13 +606,16 @@ static int comp_task(void *__cct) static struct task_struct *create_comp_task(struct ehca_comp_pool *pool, int cpu) { + struct task_struct *task; struct ehca_cpu_comp_task *cct; cct = per_cpu_ptr(pool->cpu_comp_tasks, cpu); spin_lock_init(&cct->task_lock); INIT_LIST_HEAD(&cct->cq_list); init_waitqueue_head(&cct->wait_queue); - cct->task = kthread_create(comp_task, cct, "ehca_comp/%d", cpu); + task = kthread_create(comp_task, cct, "ehca_comp/%d", cpu); + if (!IS_ERR(task)) + cct->task = task; return cct->task; } @@ -684,8 +687,10 @@ static int comp_pool_callback(struct not case CPU_UP_CANCELED: ehca_gen_dbg("CPU: %x (CPU_CANCELED)", cpu); cct = per_cpu_ptr(pool->cpu_comp_tasks, cpu); - kthread_bind(cct->task, any_online_cpu(cpu_online_map)); - destroy_comp_task(pool, cpu); + if (cct->task) { + kthread_bind(cct->task, any_online_cpu(cpu_online_map)); + destroy_comp_task(pool, cpu); + } break; case CPU_ONLINE: ehca_gen_dbg("CPU: %x (CPU_ONLINE)", cpu); - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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