From: Elena Reshetova <elena.reshetova@intel.com>
To: linux-kernel@vger.kernel.org
Cc: linux-block@vger.kernel.org, linux-scsi@vger.kernel.org,
linux-btrfs@vger.kernel.org, peterz@infradead.org,
gregkh@linuxfoundation.org, axboe@kernel.dk,
fujita.tomonori@lab.ntt.co.jp, mingo@redhat.com, clm@fb.com,
jbacik@fb.com, dsterba@suse.com,
Elena Reshetova <elena.reshetova@intel.com>,
Hans Liljestrand <ishkamiel@gmail.com>,
Kees Cook <keescook@chromium.org>,
David Windsor <dwindsor@gmail.com>
Subject: [PATCH 5/5] block: convert bsg_device.ref_count from atomic_t to refcount_t
Date: Mon, 20 Feb 2017 13:16:08 +0200 [thread overview]
Message-ID: <1487589368-17666-6-git-send-email-elena.reshetova@intel.com> (raw)
In-Reply-To: <1487589368-17666-1-git-send-email-elena.reshetova@intel.com>
refcount_t type and corresponding API should be
used instead of atomic_t when the variable is used as
a reference counter. This allows to avoid accidental
refcounter overflows that might lead to use-after-free
situations.
Signed-off-by: Elena Reshetova <elena.reshetova@intel.com>
Signed-off-by: Hans Liljestrand <ishkamiel@gmail.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: David Windsor <dwindsor@gmail.com>
---
block/bsg.c | 9 +++++----
1 file changed, 5 insertions(+), 4 deletions(-)
diff --git a/block/bsg.c b/block/bsg.c
index 74835db..6d0ceb9 100644
--- a/block/bsg.c
+++ b/block/bsg.c
@@ -21,6 +21,7 @@
#include <linux/idr.h>
#include <linux/bsg.h>
#include <linux/slab.h>
+#include <linux/refcount.h>
#include <scsi/scsi.h>
#include <scsi/scsi_ioctl.h>
@@ -38,7 +39,7 @@ struct bsg_device {
struct list_head busy_list;
struct list_head done_list;
struct hlist_node dev_list;
- atomic_t ref_count;
+ refcount_t ref_count;
int queued_cmds;
int done_cmds;
wait_queue_head_t wq_done;
@@ -711,7 +712,7 @@ static int bsg_put_device(struct bsg_device *bd)
mutex_lock(&bsg_mutex);
- do_free = atomic_dec_and_test(&bd->ref_count);
+ do_free = refcount_dec_and_test(&bd->ref_count);
if (!do_free) {
mutex_unlock(&bsg_mutex);
goto out;
@@ -763,7 +764,7 @@ static struct bsg_device *bsg_add_device(struct inode *inode,
bsg_set_block(bd, file);
- atomic_set(&bd->ref_count, 1);
+ refcount_set(&bd->ref_count, 1);
mutex_lock(&bsg_mutex);
hlist_add_head(&bd->dev_list, bsg_dev_idx_hash(iminor(inode)));
@@ -783,7 +784,7 @@ static struct bsg_device *__bsg_get_device(int minor, struct request_queue *q)
hlist_for_each_entry(bd, bsg_dev_idx_hash(minor), dev_list) {
if (bd->queue == q) {
- atomic_inc(&bd->ref_count);
+ refcount_inc(&bd->ref_count);
goto found;
}
}
--
2.7.4
next prev parent reply other threads:[~2017-02-20 11:24 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-02-20 11:16 [PATCH 0/5] block subsystem refcounter conversions Elena Reshetova
2017-02-20 11:16 ` [PATCH 1/5] block: convert bio.__bi_cnt from atomic_t to refcount_t Elena Reshetova
2017-02-20 11:16 ` [PATCH 2/5] block: convert blk_queue_tag.refcnt " Elena Reshetova
2017-02-20 11:16 ` [PATCH 3/5] block: convert blkcg_gq.refcnt " Elena Reshetova
2017-02-20 11:16 ` [PATCH 4/5] block: convert io_context.active_ref " Elena Reshetova
2017-02-20 11:16 ` Elena Reshetova [this message]
2017-02-20 15:15 ` [PATCH 0/5] block subsystem refcounter conversions Jens Axboe
2017-02-20 15:41 ` James Bottomley
2017-02-20 15:44 ` Jens Axboe
2017-02-20 16:56 ` Peter Zijlstra
2017-02-20 17:24 ` James Bottomley
2017-04-20 11:27 [PATCH 0/5] v2: " Elena Reshetova
2017-04-20 11:27 ` [PATCH 5/5] block: convert bsg_device.ref_count from atomic_t to refcount_t Elena Reshetova
2017-06-27 11:39 [PATCH 0/5] v3 block subsystem refcounter conversions Elena Reshetova
2017-06-27 11:40 ` [PATCH 5/5] block: convert bsg_device.ref_count from atomic_t to refcount_t Elena Reshetova
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