* linux-next: build warnings after merge of the block tree
@ 2013-11-26 2:29 Stephen Rothwell
2013-11-26 3:35 ` Stephen Rothwell
0 siblings, 1 reply; 6+ messages in thread
From: Stephen Rothwell @ 2013-11-26 2:29 UTC (permalink / raw)
To: Jens Axboe; +Cc: linux-next, linux-kernel, Kent Overstreet
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Hi Jens,
After merging the block tree, today's linux-next build (arm
multi_v7_defconfig) produced these warnings:
block/blk-merge.c: In function 'blk_rq_map_sg':
block/blk-merge.c:133:8: warning: 'bvprv.bv_len' may be used uninitialized in this function [-Wuninitialized]
block/blk-merge.c:171:23: note: 'bvprv.bv_len' was declared here
block/blk-merge.c:133:8: warning: 'bvprv.bv_page' may be used uninitialized in this function [-Wuninitialized]
block/blk-merge.c:171:23: note: 'bvprv.bv_page' was declared here
block/blk-merge.c:133:8: warning: 'bvprv.bv_offset' may be used uninitialized in this function [-Wuninitialized]
block/blk-merge.c:171:23: note: 'bvprv.bv_offset' was declared here
block/blk-merge.c: In function 'blk_bio_map_sg':
block/blk-merge.c:133:8: warning: 'bvprv.bv_len' may be used uninitialized in this function [-Wuninitialized]
block/blk-merge.c:233:23: note: 'bvprv.bv_len' was declared here
block/blk-merge.c:133:8: warning: 'bvprv.bv_offset' may be used uninitialized in this function [-Wuninitialized]
block/blk-merge.c:233:23: note: 'bvprv.bv_offset' was declared here
block/blk-merge.c:133:8: warning: 'bvprv.bv_page' may be used uninitialized in this function [-Wuninitialized]
block/blk-merge.c:233:23: note: 'bvprv.bv_page' was declared here
block/blk-merge.c: In function 'attempt_merge':
block/blk-merge.c:108:7: warning: 'end_bv.bv_offset' may be used uninitialized in this function [-Wuninitialized]
block/blk-merge.c:89:17: note: 'end_bv.bv_offset' was declared here
block/blk-merge.c:108:7: warning: 'end_bv.bv_page' may be used uninitialized in this function [-Wuninitialized]
block/blk-merge.c:89:17: note: 'end_bv.bv_page' was declared here
block/blk-merge.c:108:7: warning: 'end_bv.bv_len' may be used uninitialized in this function [-Wuninitialized]
block/blk-merge.c:89:17: note: 'end_bv.bv_len' was declared here
arm has its own definition of BIOVEC_PHYS_MERGEABLE() if that is relevant.
--
Cheers,
Stephen Rothwell sfr@canb.auug.org.au
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^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: linux-next: build warnings after merge of the block tree
2013-11-26 2:29 linux-next: build warnings after merge of the block tree Stephen Rothwell
@ 2013-11-26 3:35 ` Stephen Rothwell
2013-11-26 19:01 ` Olof Johansson
0 siblings, 1 reply; 6+ messages in thread
From: Stephen Rothwell @ 2013-11-26 3:35 UTC (permalink / raw)
To: Jens Axboe; +Cc: linux-next, linux-kernel, Kent Overstreet
[-- Attachment #1: Type: text/plain, Size: 2244 bytes --]
Hi all,
On Tue, 26 Nov 2013 13:29:46 +1100 Stephen Rothwell <sfr@canb.auug.org.au> wrote:
>
> After merging the block tree, today's linux-next build (arm
> multi_v7_defconfig) produced these warnings:
>
> block/blk-merge.c: In function 'blk_rq_map_sg':
> block/blk-merge.c:133:8: warning: 'bvprv.bv_len' may be used uninitialized in this function [-Wuninitialized]
> block/blk-merge.c:171:23: note: 'bvprv.bv_len' was declared here
> block/blk-merge.c:133:8: warning: 'bvprv.bv_page' may be used uninitialized in this function [-Wuninitialized]
> block/blk-merge.c:171:23: note: 'bvprv.bv_page' was declared here
> block/blk-merge.c:133:8: warning: 'bvprv.bv_offset' may be used uninitialized in this function [-Wuninitialized]
> block/blk-merge.c:171:23: note: 'bvprv.bv_offset' was declared here
> block/blk-merge.c: In function 'blk_bio_map_sg':
> block/blk-merge.c:133:8: warning: 'bvprv.bv_len' may be used uninitialized in this function [-Wuninitialized]
> block/blk-merge.c:233:23: note: 'bvprv.bv_len' was declared here
> block/blk-merge.c:133:8: warning: 'bvprv.bv_offset' may be used uninitialized in this function [-Wuninitialized]
> block/blk-merge.c:233:23: note: 'bvprv.bv_offset' was declared here
> block/blk-merge.c:133:8: warning: 'bvprv.bv_page' may be used uninitialized in this function [-Wuninitialized]
> block/blk-merge.c:233:23: note: 'bvprv.bv_page' was declared here
> block/blk-merge.c: In function 'attempt_merge':
> block/blk-merge.c:108:7: warning: 'end_bv.bv_offset' may be used uninitialized in this function [-Wuninitialized]
> block/blk-merge.c:89:17: note: 'end_bv.bv_offset' was declared here
> block/blk-merge.c:108:7: warning: 'end_bv.bv_page' may be used uninitialized in this function [-Wuninitialized]
> block/blk-merge.c:89:17: note: 'end_bv.bv_page' was declared here
> block/blk-merge.c:108:7: warning: 'end_bv.bv_len' may be used uninitialized in this function [-Wuninitialized]
> block/blk-merge.c:89:17: note: 'end_bv.bv_len' was declared here
>
> arm has its own definition of BIOVEC_PHYS_MERGEABLE() if that is relevant.
For an easier test case, the i386 defcongig does this as well.
--
Cheers,
Stephen Rothwell sfr@canb.auug.org.au
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^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: linux-next: build warnings after merge of the block tree
2013-11-26 3:35 ` Stephen Rothwell
@ 2013-11-26 19:01 ` Olof Johansson
2013-11-26 19:02 ` Jens Axboe
0 siblings, 1 reply; 6+ messages in thread
From: Olof Johansson @ 2013-11-26 19:01 UTC (permalink / raw)
To: Stephen Rothwell; +Cc: Jens Axboe, linux-next, linux-kernel, Kent Overstreet
On Mon, Nov 25, 2013 at 7:35 PM, Stephen Rothwell <sfr@canb.auug.org.au> wrote:
> Hi all,
>
> On Tue, 26 Nov 2013 13:29:46 +1100 Stephen Rothwell <sfr@canb.auug.org.au> wrote:
>>
>> After merging the block tree, today's linux-next build (arm
>> multi_v7_defconfig) produced these warnings:
>>
>> block/blk-merge.c: In function 'blk_rq_map_sg':
>> block/blk-merge.c:133:8: warning: 'bvprv.bv_len' may be used uninitialized in this function [-Wuninitialized]
>> block/blk-merge.c:171:23: note: 'bvprv.bv_len' was declared here
>> block/blk-merge.c:133:8: warning: 'bvprv.bv_page' may be used uninitialized in this function [-Wuninitialized]
>> block/blk-merge.c:171:23: note: 'bvprv.bv_page' was declared here
>> block/blk-merge.c:133:8: warning: 'bvprv.bv_offset' may be used uninitialized in this function [-Wuninitialized]
>> block/blk-merge.c:171:23: note: 'bvprv.bv_offset' was declared here
>> block/blk-merge.c: In function 'blk_bio_map_sg':
>> block/blk-merge.c:133:8: warning: 'bvprv.bv_len' may be used uninitialized in this function [-Wuninitialized]
>> block/blk-merge.c:233:23: note: 'bvprv.bv_len' was declared here
>> block/blk-merge.c:133:8: warning: 'bvprv.bv_offset' may be used uninitialized in this function [-Wuninitialized]
>> block/blk-merge.c:233:23: note: 'bvprv.bv_offset' was declared here
>> block/blk-merge.c:133:8: warning: 'bvprv.bv_page' may be used uninitialized in this function [-Wuninitialized]
>> block/blk-merge.c:233:23: note: 'bvprv.bv_page' was declared here
>> block/blk-merge.c: In function 'attempt_merge':
>> block/blk-merge.c:108:7: warning: 'end_bv.bv_offset' may be used uninitialized in this function [-Wuninitialized]
>> block/blk-merge.c:89:17: note: 'end_bv.bv_offset' was declared here
>> block/blk-merge.c:108:7: warning: 'end_bv.bv_page' may be used uninitialized in this function [-Wuninitialized]
>> block/blk-merge.c:89:17: note: 'end_bv.bv_page' was declared here
>> block/blk-merge.c:108:7: warning: 'end_bv.bv_len' may be used uninitialized in this function [-Wuninitialized]
>> block/blk-merge.c:89:17: note: 'end_bv.bv_len' was declared here
>>
>> arm has its own definition of BIOVEC_PHYS_MERGEABLE() if that is relevant.
>
> For an easier test case, the i386 defcongig does this as well.
I just noticed that i see this with gcc 4.7.0, but 4.8.1 does not warn.
-Olof
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: linux-next: build warnings after merge of the block tree
2013-11-26 19:01 ` Olof Johansson
@ 2013-11-26 19:02 ` Jens Axboe
2013-11-27 0:39 ` [PATCH] block: Silence spurious compiler warnings Kent Overstreet
0 siblings, 1 reply; 6+ messages in thread
From: Jens Axboe @ 2013-11-26 19:02 UTC (permalink / raw)
To: Olof Johansson, Stephen Rothwell
Cc: linux-next, linux-kernel, Kent Overstreet
On 11/26/2013 12:01 PM, Olof Johansson wrote:
> On Mon, Nov 25, 2013 at 7:35 PM, Stephen Rothwell <sfr@canb.auug.org.au> wrote:
>> Hi all,
>>
>> On Tue, 26 Nov 2013 13:29:46 +1100 Stephen Rothwell <sfr@canb.auug.org.au> wrote:
>>>
>>> After merging the block tree, today's linux-next build (arm
>>> multi_v7_defconfig) produced these warnings:
>>>
>>> block/blk-merge.c: In function 'blk_rq_map_sg':
>>> block/blk-merge.c:133:8: warning: 'bvprv.bv_len' may be used uninitialized in this function [-Wuninitialized]
>>> block/blk-merge.c:171:23: note: 'bvprv.bv_len' was declared here
>>> block/blk-merge.c:133:8: warning: 'bvprv.bv_page' may be used uninitialized in this function [-Wuninitialized]
>>> block/blk-merge.c:171:23: note: 'bvprv.bv_page' was declared here
>>> block/blk-merge.c:133:8: warning: 'bvprv.bv_offset' may be used uninitialized in this function [-Wuninitialized]
>>> block/blk-merge.c:171:23: note: 'bvprv.bv_offset' was declared here
>>> block/blk-merge.c: In function 'blk_bio_map_sg':
>>> block/blk-merge.c:133:8: warning: 'bvprv.bv_len' may be used uninitialized in this function [-Wuninitialized]
>>> block/blk-merge.c:233:23: note: 'bvprv.bv_len' was declared here
>>> block/blk-merge.c:133:8: warning: 'bvprv.bv_offset' may be used uninitialized in this function [-Wuninitialized]
>>> block/blk-merge.c:233:23: note: 'bvprv.bv_offset' was declared here
>>> block/blk-merge.c:133:8: warning: 'bvprv.bv_page' may be used uninitialized in this function [-Wuninitialized]
>>> block/blk-merge.c:233:23: note: 'bvprv.bv_page' was declared here
>>> block/blk-merge.c: In function 'attempt_merge':
>>> block/blk-merge.c:108:7: warning: 'end_bv.bv_offset' may be used uninitialized in this function [-Wuninitialized]
>>> block/blk-merge.c:89:17: note: 'end_bv.bv_offset' was declared here
>>> block/blk-merge.c:108:7: warning: 'end_bv.bv_page' may be used uninitialized in this function [-Wuninitialized]
>>> block/blk-merge.c:89:17: note: 'end_bv.bv_page' was declared here
>>> block/blk-merge.c:108:7: warning: 'end_bv.bv_len' may be used uninitialized in this function [-Wuninitialized]
>>> block/blk-merge.c:89:17: note: 'end_bv.bv_len' was declared here
>>>
>>> arm has its own definition of BIOVEC_PHYS_MERGEABLE() if that is relevant.
>>
>> For an easier test case, the i386 defcongig does this as well.
>
> I just noticed that i see this with gcc 4.7.0, but 4.8.1 does not warn.
That's good, because it's not a bug. But arguably we should shut up 4.7
as well, however...
--
Jens Axboe
^ permalink raw reply [flat|nested] 6+ messages in thread
* [PATCH] block: Silence spurious compiler warnings
2013-11-26 19:02 ` Jens Axboe
@ 2013-11-27 0:39 ` Kent Overstreet
2013-11-28 0:50 ` Stephen Rothwell
0 siblings, 1 reply; 6+ messages in thread
From: Kent Overstreet @ 2013-11-27 0:39 UTC (permalink / raw)
To: Jens Axboe; +Cc: Olof Johansson, Stephen Rothwell, linux-next, linux-kernel
>From 46e7081430f5f483906f496733a23f8e9d898879 Mon Sep 17 00:00:00 2001
From: Kent Overstreet <kmo@daterainc.com>
Date: Tue, 26 Nov 2013 16:36:49 -0800
Subject: [PATCH] block: Silence spurious compiler warnings
Signed-off-by: Kent Overstreet <kmo@daterainc.com>
---
On Tue, Nov 26, 2013 at 12:02:08PM -0700, Jens Axboe wrote:
> On 11/26/2013 12:01 PM, Olof Johansson wrote:
> > I just noticed that i see this with gcc 4.7.0, but 4.8.1 does not warn.
>
> That's good, because it's not a bug. But arguably we should shut up 4.7
> as well, however...
Here you go:
block/blk-merge.c | 6 ++++++
1 file changed, 6 insertions(+)
diff --git a/block/blk-merge.c b/block/blk-merge.c
index 05c17be..0b097f6 100644
--- a/block/blk-merge.c
+++ b/block/blk-merge.c
@@ -89,6 +89,8 @@ static int blk_phys_contig_segment(struct request_queue *q, struct bio *bio,
struct bio_vec end_bv, nxt_bv;
struct bvec_iter iter;
+ uninitialized_var(end_bv);
+
if (!blk_queue_cluster(q))
return 0;
@@ -173,6 +175,8 @@ int blk_rq_map_sg(struct request_queue *q, struct request *rq,
struct scatterlist *sg;
int nsegs, cluster;
+ uninitialized_var(bvprv);
+
nsegs = 0;
cluster = blk_queue_cluster(q);
@@ -235,6 +239,8 @@ int blk_bio_map_sg(struct request_queue *q, struct bio *bio,
int nsegs, cluster;
struct bvec_iter iter;
+ uninitialized_var(bvprv);
+
nsegs = 0;
cluster = blk_queue_cluster(q);
--
1.8.4.4
^ permalink raw reply related [flat|nested] 6+ messages in thread
* Re: [PATCH] block: Silence spurious compiler warnings
2013-11-27 0:39 ` [PATCH] block: Silence spurious compiler warnings Kent Overstreet
@ 2013-11-28 0:50 ` Stephen Rothwell
0 siblings, 0 replies; 6+ messages in thread
From: Stephen Rothwell @ 2013-11-28 0:50 UTC (permalink / raw)
To: Kent Overstreet; +Cc: Jens Axboe, Olof Johansson, linux-next, linux-kernel
[-- Attachment #1: Type: text/plain, Size: 2383 bytes --]
Hi Kent,
On Tue, 26 Nov 2013 16:39:49 -0800 Kent Overstreet <kmo@daterainc.com> wrote:
>
> From 46e7081430f5f483906f496733a23f8e9d898879 Mon Sep 17 00:00:00 2001
> From: Kent Overstreet <kmo@daterainc.com>
> Date: Tue, 26 Nov 2013 16:36:49 -0800
> Subject: [PATCH] block: Silence spurious compiler warnings
>
> Signed-off-by: Kent Overstreet <kmo@daterainc.com>
Unfortunately, that did not work :-(
I am till getting these warnings into today's linux-next after merging
the block tree (arm multi_v7_defconfig, gcc 4.6):
block/blk-merge.c: In function 'blk_rq_map_sg':
block/blk-merge.c:135:8: warning: 'bvprv.bv_page' may be used uninitialized in this function [-Wuninitialized]
block/blk-merge.c:173:23: note: 'bvprv.bv_page' was declared here
block/blk-merge.c:135:8: warning: 'bvprv.bv_len' may be used uninitialized in this function [-Wuninitialized]
block/blk-merge.c:173:23: note: 'bvprv.bv_len' was declared here
block/blk-merge.c:135:8: warning: 'bvprv.bv_offset' may be used uninitialized in this function [-Wuninitialized]
block/blk-merge.c:173:23: note: 'bvprv.bv_offset' was declared here
block/blk-merge.c: In function 'blk_bio_map_sg':
block/blk-merge.c:135:8: warning: 'bvprv.bv_offset' may be used uninitialized in this function [-Wuninitialized]
block/blk-merge.c:237:23: note: 'bvprv.bv_offset' was declared here
block/blk-merge.c:135:8: warning: 'bvprv.bv_len' may be used uninitialized in this function [-Wuninitialized]
block/blk-merge.c:237:23: note: 'bvprv.bv_len' was declared here
block/blk-merge.c:135:8: warning: 'bvprv.bv_page' may be used uninitialized in this function [-Wuninitialized]
block/blk-merge.c:237:23: note: 'bvprv.bv_page' was declared here
block/blk-merge.c: In function 'attempt_merge':
block/blk-merge.c:110:7: warning: 'end_bv.bv_offset' may be used uninitialized in this function [-Wuninitialized]
block/blk-merge.c:89:17: note: 'end_bv.bv_offset' was declared here
block/blk-merge.c:110:7: warning: 'end_bv.bv_len' may be used uninitialized in this function [-Wuninitialized]
block/blk-merge.c:89:17: note: 'end_bv.bv_len' was declared here
block/blk-merge.c:110:7: warning: 'end_bv.bv_page' may be used uninitialized in this function [-Wuninitialized]
block/blk-merge.c:89:17: note: 'end_bv.bv_page' was declared here
--
Cheers,
Stephen Rothwell sfr@canb.auug.org.au
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2013-11-26 2:29 linux-next: build warnings after merge of the block tree Stephen Rothwell
2013-11-26 3:35 ` Stephen Rothwell
2013-11-26 19:01 ` Olof Johansson
2013-11-26 19:02 ` Jens Axboe
2013-11-27 0:39 ` [PATCH] block: Silence spurious compiler warnings Kent Overstreet
2013-11-28 0:50 ` Stephen Rothwell
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