Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
[PATCH] cfq-iosched: fix crash in do_div()
We don't clear the seek stat values in cfq_alloc_io_context(), and if
->seek_mean is unlucky enough to be set to -36 by chance, the first
invocation of cfq_update_io_seektime() will oops with a divide by zero
in do_div().
Just memset the entire cic instead of filling invididual values
independently.
Signed-off-by: Jens Axboe <axboe@suse.de>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
authored by
Jens Axboe
and committed by
Linus Torvalds
553698f9
9cedc194
+3
-8
+3
-8
block/cfq-iosched.c
+3
-8
block/cfq-iosched.c
···
1323
1323
struct cfq_io_context *cic = kmem_cache_alloc(cfq_ioc_pool, gfp_mask);
1324
1324
1325
1325
if (cic) {
1326
-
RB_CLEAR(&cic->rb_node);
1327
-
cic->key = NULL;
1328
-
cic->cfqq[ASYNC] = NULL;
1329
-
cic->cfqq[SYNC] = NULL;
1326
+
memset(cic, 0, sizeof(*cic));
1327
+
RB_CLEAR_COLOR(&cic->rb_node);
1330
1328
cic->last_end_request = jiffies;
1331
-
cic->ttime_total = 0;
1332
-
cic->ttime_samples = 0;
1333
-
cic->ttime_mean = 0;
1329
+
INIT_LIST_HEAD(&cic->queue_list);
1334
1330
cic->dtor = cfq_free_io_context;
1335
1331
cic->exit = cfq_exit_io_context;
1336
-
INIT_LIST_HEAD(&cic->queue_list);
1337
1332
atomic_inc(&ioc_count);
1338
1333
}
1339
1334