From b8ea2cb5120a92fe63053a2896be42abbb919a76 Mon Sep 17 00:00:00 2001 From: Zachary Amsden Date: Wed, 9 Nov 2005 13:23:01 +0100 Subject: [PATCH] [BLOCK] elevator init fixes I got a panic in the elevator code, backtrace : Unable to handle kernel NULL pointer dereference at virtual address 00000060 .. EIP is at elevator_put+0x0/0x30 (null elevator_type passed) .. elevator_init+0x38 blk_init_queu_node+0xc9 floppy_init+0xdb do_initcalls+0x23 init+0x10a init+0x0 Clearly if the kmalloc here fails, e->elevator_type is not yet set; this appears to be the correct fix, but I think I probably hit the second case due to a race condition. Someone more familiar with the elevator code should look at this more closely until I can determine if I can reproduce. Signed-off-by: Zachary Amsden Signed-off-by: Andrew Morton Signed-off-by: Jens Axboe --- block/elevator.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/block/elevator.c b/block/elevator.c index d4a49a3df829..23cfbe528be1 100644 --- a/block/elevator.c +++ b/block/elevator.c @@ -190,14 +190,14 @@ int elevator_init(request_queue_t *q, char *name) eq = kmalloc(sizeof(struct elevator_queue), GFP_KERNEL); if (!eq) { - elevator_put(e->elevator_type); + elevator_put(e); return -ENOMEM; } ret = elevator_attach(q, e, eq); if (ret) { kfree(eq); - elevator_put(e->elevator_type); + elevator_put(e); } return ret; -- 2.30.2