From: Ilya Dryomov <idryomov@gmail.com>
To: Arnd Bergmann <arnd@arndb.de>
Cc: Sage Weil <sage@redhat.com>,
Linus Torvalds <torvalds@linux-foundation.org>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
Alex Elder <elder@kernel.org>,
Mike Christie <mchristi@redhat.com>,
Ceph Development <ceph-devel@vger.kernel.org>
Subject: Re: [PATCH 11/28] block: rdb: false-postive gcc-4.9 -Wmaybe-uninitialized
Date: Tue, 18 Oct 2016 11:57:33 +0200 [thread overview]
Message-ID: <CAOi1vP-N-Qp4_LU=MMoPp+wH5t+JoDxFsVgMa=65CBO=HTV_DA@mail.gmail.com> (raw)
In-Reply-To: <20161017221037.1781185-2-arnd@arndb.de>
On Tue, Oct 18, 2016 at 12:10 AM, Arnd Bergmann <arnd@arndb.de> wrote:
> When building with gcc-4.9 -Wmaybe-uninitialized, we get a bogus
> warning in rbd_watch_cb, as the variable is not used at all
> in the one case in which it is not initialized first:
>
> drivers/block/rbd.c: In function ‘rbd_watch_cb’:
> drivers/block/rbd.c:3690:5: error: ‘struct_v’ may be used uninitialized in this function [-Werror=maybe-uninitialized]
> drivers/block/rbd.c:3759:5: note: ‘struct_v’ was declared here
>
> Later compiler versions fix this, but adding another initialization
> here is harmless and lets us build cleanly with 4.9 as well.
>
> Signed-off-by: Arnd Bergmann <arnd@arndb.de>
> ---
> drivers/block/rbd.c | 1 +
> 1 file changed, 1 insertion(+)
>
> diff --git a/drivers/block/rbd.c b/drivers/block/rbd.c
> index abb7162..4ab990b 100644
> --- a/drivers/block/rbd.c
> +++ b/drivers/block/rbd.c
> @@ -3776,6 +3776,7 @@ static void rbd_watch_cb(void *arg, u64 notify_id, u64 cookie,
> } else {
> /* legacy notification for header updates */
> notify_op = RBD_NOTIFY_OP_HEADER_UPDATE;
> + struct_v = 0;
> len = 0;
> }
It already got silenced by initializing at declaration in one of the
downstream trees, so I'd rather we do
@@ -3756,7 +3819,7 @@ static void rbd_watch_cb(void *arg, u64
notify_id, u64 cookie,
struct rbd_device *rbd_dev = arg;
void *p = data;
void *const end = p + data_len;
- u8 struct_v;
+ u8 struct_v = 0;
u32 len;
u32 notify_op;
int ret;
to reduce the churn.
The "block" prefix is redundant and "rdb" should be "rbd" in the subject.
Thanks,
Ilya
next prev parent reply other threads:[~2016-10-18 9:57 UTC|newest]
Thread overview: 74+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-10-17 22:03 [PATCH 00/28] Reenable maybe-uninitialized warnings Arnd Bergmann
2016-10-17 22:05 ` [PATCH 01/28] [v2] netfilter: nf_tables: avoid uninitialized variable warning Arnd Bergmann
2016-10-18 15:23 ` Pablo Neira Ayuso
2016-10-17 22:05 ` [PATCH 02/28] [v2] mtd: mtk: avoid warning in mtk_ecc_encode Arnd Bergmann
2016-10-18 5:19 ` Boris Brezillon
[not found] ` <1476785552.24626.4.camel@mtkswgap22>
2016-10-18 19:45 ` Boris Brezillon
2016-10-17 22:05 ` [PATCH 03/28] [v2] infiniband: shut up a maybe-uninitialized warning Arnd Bergmann
2016-10-18 6:47 ` Haggai Eran
2016-10-18 10:18 ` Arnd Bergmann
2016-10-18 10:32 ` Haggai Eran
2016-10-17 22:05 ` [PATCH 04/28] f2fs: replace a build-time warning with runtime WARN_ON Arnd Bergmann
2016-10-26 14:05 ` [f2fs-dev] " Chao Yu
2016-10-26 14:57 ` Arnd Bergmann
2016-10-27 11:41 ` Chao Yu
2016-10-17 22:05 ` [PATCH 05/28] ext2: avoid bogus -Wmaybe-uninitialized warning Arnd Bergmann
2016-10-18 5:15 ` Christoph Hellwig
2016-10-18 9:30 ` Jan Kara
2016-10-17 22:05 ` [PATCH 06/28] NFSv4.1: work around " Arnd Bergmann
2016-10-17 22:08 ` [PATCH 07/28] ceph: avoid false positive maybe-uninitialized warning Arnd Bergmann
2016-10-18 2:07 ` Yan, Zheng
2016-10-17 22:08 ` [PATCH 08/28] staging: lustre: restore initialization of return code Arnd Bergmann
[not found] ` <CY4PR11MB1751050A7C7AF840E94DDE60CBD00@CY4PR11MB1751.namprd11.prod.outlook.com>
2016-10-17 22:29 ` [lustre-devel] " Arnd Bergmann
2016-10-17 22:37 ` Linus Torvalds
2016-10-17 23:00 ` Arnd Bergmann
2016-10-17 22:42 ` [PATCH 08/28 v2] " Arnd Bergmann
2016-10-17 22:08 ` [PATCH 09/28] staging: lustre: remove broken dead code in cfs_cpt_table_create_pattern Arnd Bergmann
2016-10-17 22:10 ` [PATCH 10/28] UBI: fix uninitialized access of vid_hdr pointer Arnd Bergmann
2016-10-18 5:17 ` Boris Brezillon
2016-10-17 22:10 ` [PATCH 11/28] block: rdb: false-postive gcc-4.9 -Wmaybe-uninitialized Arnd Bergmann
2016-10-18 9:57 ` Ilya Dryomov [this message]
2016-10-18 10:04 ` Arnd Bergmann
2016-10-17 22:12 ` [PATCH 12/28] [media] rc: print correct variable for z8f0811 Arnd Bergmann
2016-10-17 22:13 ` [PATCH 13/28] [media] dib0700: fix uninitialized data on 'repeat' event Arnd Bergmann
2016-10-17 22:13 ` [PATCH 14/28] iio: accel: sca3000_core: avoid potentially uninitialized variable Arnd Bergmann
2016-10-23 21:25 ` Jonathan Cameron
2016-10-17 22:13 ` [PATCH 15/28] crypto: aesni: avoid -Wmaybe-uninitialized warning Arnd Bergmann
2016-10-17 22:13 ` [PATCH 16/28] pcmcia: fix return value of soc_pcmcia_regulator_set Arnd Bergmann
2016-10-18 9:42 ` Russell King - ARM Linux
2016-10-17 22:13 ` [PATCH 17/28] spi: fsl-espi: avoid processing uninitalized data on error Arnd Bergmann
2016-10-24 17:27 ` Mark Brown
2016-10-24 18:36 ` Heiner Kallweit
2016-10-24 18:45 ` Mark Brown
2016-10-24 20:37 ` Arnd Bergmann
2016-10-25 19:13 ` Mark Brown
2016-10-25 20:57 ` Arnd Bergmann
2016-10-26 10:15 ` Applied "spi: fsl-espi: avoid processing uninitalized data on error" to the spi tree Mark Brown
2016-10-26 18:11 ` Merge problem: " Heiner Kallweit
2016-10-26 21:59 ` Mark Brown
2016-10-17 22:13 ` [PATCH 18/28] drm: avoid uninitialized timestamp use in wait_vblank Arnd Bergmann
2016-10-17 23:47 ` Mario Kleiner
2016-10-18 7:46 ` Daniel Vetter
2016-10-17 22:13 ` [PATCH 19/28] brcmfmac: avoid maybe-uninitialized warning in brcmf_cfg80211_start_ap Arnd Bergmann
2016-10-26 6:49 ` Kalle Valo
2016-10-26 9:57 ` Arnd Bergmann
2016-10-26 11:11 ` Kalle Valo
2016-10-27 15:05 ` [19/28] " Kalle Valo
2016-10-17 22:16 ` [PATCH 20/28] net: bcm63xx: avoid referencing uninitialized variable Arnd Bergmann
2016-10-18 18:21 ` David Miller
2016-10-17 22:16 ` [PATCH 21/28] net/hyperv: avoid " Arnd Bergmann
2016-10-18 18:21 ` David Miller
2016-10-17 22:16 ` [PATCH 22/28] x86: apm: avoid uninitialized data Arnd Bergmann
2016-10-18 13:05 ` Jiri Kosina
2016-10-18 21:35 ` Luis R. Rodriguez
2016-10-17 22:16 ` [PATCH 23/28] x86: mark target address as output in 'insb' asm Arnd Bergmann
2016-10-17 22:16 ` [PATCH 24/28] x86: math-emu: possible uninitialized variable use Arnd Bergmann
2016-10-17 22:16 ` [PATCH 25/28] s390: pci: don't print uninitialized data for debugging Arnd Bergmann
2016-10-18 6:48 ` Martin Schwidefsky
2016-10-18 8:53 ` Sebastian Ott
2016-10-17 22:16 ` [PATCH 26/28] nios2: fix timer initcall return value Arnd Bergmann
2016-10-24 0:54 ` Ley Foon Tan
2016-10-17 22:16 ` [PATCH 27/28] rocker: fix maybe-uninitialized warning Arnd Bergmann
2016-10-18 18:21 ` David Miller
2016-10-17 22:19 ` [PATCH 28/28] Kbuild: bring back -Wmaybe-uninitialized warning Arnd Bergmann
2016-10-18 5:08 ` [PATCH 00/28] Reenable maybe-uninitialized warnings Christoph Hellwig
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