From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id E7F0D405C2; Mon, 8 Jan 2024 12:27:49 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="UPsGJcl1" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 44F53C433C7; Mon, 8 Jan 2024 12:27:48 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1704716869; bh=XT1YEEoBYL9YDiIX/x8rgxCuvHmV/PTauF415QqPIFQ=; h=From:To:Cc:Subject:Date:From; b=UPsGJcl1g9EiAthi4CpNsl0yNSWFFCHkd2ZUbk6CPMt34BMDzCtyhQ+yca1YMlyBY Cql7306y2Q7Nn85Nuz1FCd0JTfdsdsmOvi+V4YV+fFxy119KClUTIlxh1NT+KFeoKY MZpaB7OGQETIMSHaflY6/9l4S07nJqm9h+39n1NQ6aOsqa3uDyWEoUod0N46iLPlhi RPnolo36oi829R/GkUy7NdzRIIwkMV/ZnE9kQ0pNJXQDc5nEv1QUcsgDlUmVgSpFNq TXD9HiTkn3unCs6nevPT3VmvnbCyYnaQNWJ7Sm+o2QutC34hu+g0hb9g3xiyQpWTkN /ZukCNaH92M/w== From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Stefan Hajnoczi , Suwan Kim , kernel test robot , "Michael S . Tsirkin" , Sasha Levin , jasowang@redhat.com, axboe@kernel.dk, virtualization@lists.linux.dev, linux-block@vger.kernel.org Subject: [PATCH AUTOSEL 6.6 1/8] virtio_blk: fix snprintf truncation compiler warning Date: Mon, 8 Jan 2024 07:27:17 -0500 Message-ID: <20240108122745.2090122-1-sashal@kernel.org> X-Mailer: git-send-email 2.43.0 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 X-stable: review X-Patchwork-Hint: Ignore X-stable-base: Linux 6.6.10 Content-Transfer-Encoding: 8bit From: Stefan Hajnoczi [ Upstream commit b8e0792449928943c15d1af9f63816911d139267 ] Commit 4e0400525691 ("virtio-blk: support polling I/O") triggers the following gcc 13 W=1 warnings: drivers/block/virtio_blk.c: In function ‘init_vq’: drivers/block/virtio_blk.c:1077:68: warning: ‘%d’ directive output may be truncated writing between 1 and 11 bytes into a region of size 7 [-Wformat-truncation=] 1077 | snprintf(vblk->vqs[i].name, VQ_NAME_LEN, "req_poll.%d", i); | ^~ drivers/block/virtio_blk.c:1077:58: note: directive argument in the range [-2147483648, 65534] 1077 | snprintf(vblk->vqs[i].name, VQ_NAME_LEN, "req_poll.%d", i); | ^~~~~~~~~~~~~ drivers/block/virtio_blk.c:1077:17: note: ‘snprintf’ output between 11 and 21 bytes into a destination of size 16 1077 | snprintf(vblk->vqs[i].name, VQ_NAME_LEN, "req_poll.%d", i); | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ This is a false positive because the lower bound -2147483648 is incorrect. The true range of i is [0, num_vqs - 1] where 0 < num_vqs < 65536. The code mixes int, unsigned short, and unsigned int types in addition to using "%d" for an unsigned value. Use unsigned short and "%u" consistently to solve the compiler warning. Cc: Suwan Kim Reported-by: kernel test robot Closes: https://lore.kernel.org/oe-kbuild-all/202312041509.DIyvEt9h-lkp@intel.com/ Signed-off-by: Stefan Hajnoczi Message-Id: <20231204140743.1487843-1-stefanha@redhat.com> Signed-off-by: Michael S. Tsirkin Signed-off-by: Sasha Levin --- drivers/block/virtio_blk.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) diff --git a/drivers/block/virtio_blk.c b/drivers/block/virtio_blk.c index 4a4b9bad551e8..225c86c74d4e9 100644 --- a/drivers/block/virtio_blk.c +++ b/drivers/block/virtio_blk.c @@ -1021,12 +1021,12 @@ static void virtblk_config_changed(struct virtio_device *vdev) static int init_vq(struct virtio_blk *vblk) { int err; - int i; + unsigned short i; vq_callback_t **callbacks; const char **names; struct virtqueue **vqs; unsigned short num_vqs; - unsigned int num_poll_vqs; + unsigned short num_poll_vqs; struct virtio_device *vdev = vblk->vdev; struct irq_affinity desc = { 0, }; @@ -1070,13 +1070,13 @@ static int init_vq(struct virtio_blk *vblk) for (i = 0; i < num_vqs - num_poll_vqs; i++) { callbacks[i] = virtblk_done; - snprintf(vblk->vqs[i].name, VQ_NAME_LEN, "req.%d", i); + snprintf(vblk->vqs[i].name, VQ_NAME_LEN, "req.%u", i); names[i] = vblk->vqs[i].name; } for (; i < num_vqs; i++) { callbacks[i] = NULL; - snprintf(vblk->vqs[i].name, VQ_NAME_LEN, "req_poll.%d", i); + snprintf(vblk->vqs[i].name, VQ_NAME_LEN, "req_poll.%u", i); names[i] = vblk->vqs[i].name; } -- 2.43.0