[glommer-memcg:slab-common/kmalloc 28/30] include/linux/slab_def.h:135:27: warning: array subscript

[glommer-memcg:slab-common/kmalloc 28/30] include/linux/slab_def.h:135:27: warning: array subscript

[Fengguang Wu]

Hi Christoph,

FYI, there are new compile warnings show up in

tree:   git://git.kernel.org/pub/scm/linux/kernel/git/glommer/memcg.git slab-common/kmalloc
head:   f957c1ead131972db578b945e25982f4607da6ba
commit: 55a6b9f968a877c728ed6e438fa68741a7711d89 [28/30] CK1 [12/13] Common names for the array of kmalloc caches
config: blackfin-BF533-EZKIT_defconfig

All warnings:

In file included from include/linux/slab.h:314:0,
                 from include/linux/proc_fs.h:4,
                 from fs/proc/stat.c:6:
fs/proc/stat.c: In function 'stat_open':
include/linux/slab_def.h:135:27: warning: array subscript is above array bounds [-Warray-bounds]

vim +135 include/linux/slab_def.h

36555751 (Eduard - Gabriel Munteanu 2008-08-10  119) 	struct kmem_cache *cachep;
36555751 (Eduard - Gabriel Munteanu 2008-08-10  120) 	void *ret;
36555751 (Eduard - Gabriel Munteanu 2008-08-10  121) 
2e892f43 (Christoph Lameter         2006-12-13  122) 	if (__builtin_constant_p(size)) {
9e396407 (Christoph Lameter         2012-09-26  123) 		int i;
6cb8f913 (Christoph Lameter         2007-07-17  124) 
6cb8f913 (Christoph Lameter         2007-07-17  125) 		if (!size)
6cb8f913 (Christoph Lameter         2007-07-17  126) 			return ZERO_SIZE_PTR;
6cb8f913 (Christoph Lameter         2007-07-17  127) 
9e396407 (Christoph Lameter         2012-09-26  128) 		i = kmalloc_index(size);
9e396407 (Christoph Lameter         2012-09-26  129) 
4b51d669 (Christoph Lameter         2007-02-10  130) #ifdef CONFIG_ZONE_DMA
4b51d669 (Christoph Lameter         2007-02-10  131) 		if (flags & GFP_DMA)
24e75516 (Christoph Lameter         2012-09-26  132) 			cachep = kmalloc_dma_caches[i];
36555751 (Eduard - Gabriel Munteanu 2008-08-10  133) 		else
4b51d669 (Christoph Lameter         2007-02-10  134) #endif
24e75516 (Christoph Lameter         2012-09-26 @135) 			cachep = kmalloc_caches[i];
36555751 (Eduard - Gabriel Munteanu 2008-08-10  136) 
85beb586 (Steven Rostedt            2010-11-24  137) 		ret = kmem_cache_alloc_trace(size, cachep, flags);
36555751 (Eduard - Gabriel Munteanu 2008-08-10  138) 
36555751 (Eduard - Gabriel Munteanu 2008-08-10  139) 		return ret;
2e892f43 (Christoph Lameter         2006-12-13  140) 	}
2e892f43 (Christoph Lameter         2006-12-13  141) 	return __kmalloc(size, flags);
2e892f43 (Christoph Lameter         2006-12-13  142) }
2e892f43 (Christoph Lameter         2006-12-13  143) 

---
0-DAY kernel build testing backend         Open Source Technology Centre
Fengguang Wu, Yuanhan Liu                              Intel Corporation

Re: [glommer-memcg:slab-common/kmalloc 28/30] mm/slab.c:2409:14: error: 'malloc_sizes' undeclared

[Christoph Lameter]

On Fri, 28 Sep 2012, Fengguang Wu wrote:

> tree:   git://git.kernel.org/pub/scm/linux/kernel/git/glommer/memcg.git slab-common/kmalloc
> head:   f957c1ead131972db578b945e25982f4607da6ba
> commit: 55a6b9f968a877c728ed6e438fa68741a7711d89 [28/30] CK1 [12/13] Common names for the array of kmalloc caches
> config: x86_64-allyesdebian (attached as .config)
>
> All error/warnings:
>
> mm/slab.c: In function '__kmem_cache_create':
> mm/slab.c:2409:14: error: 'malloc_sizes' undeclared (first use in this function)
> mm/slab.c:2409:14: note: each undeclared identifier is reported only once for each function it appears in
> mm/slab.c:2410:102: error: 'align' undeclared (first use in this function)

Fixed by this patch:

Index: linux/mm/slab.c
=================================--- linux.orig/mm/slab.c	2012-09-28 12:20:41.504733528 -0500
+++ linux/mm/slab.c	2012-09-28 12:20:12.732133191 -0500
@@ -2406,7 +2406,7 @@ __kmem_cache_create (struct kmem_cache *
 			size += BYTES_PER_WORD;
 	}
 #if FORCED_DEBUG && defined(CONFIG_DEBUG_PAGEALLOC)
-	if (size >= malloc_sizes[INDEX_L3 + 1].cs_size
+	if (size >= kmalloc_size(INDEX_L3 + 1))
 	    && cachep->object_size > cache_line_size() && ALIGN(size, align) < PAGE_SIZE) {
 		cachep->obj_offset += PAGE_SIZE - ALIGN(size, align);
 		size = PAGE_SIZE;

Will be folded into the patchset for the next release.

Re: [glommer-memcg:slab-common/kmalloc 28/30] include/linux/slab_def.h:135:27: warning: array subscr

[Christoph Lameter]

On Fri, 28 Sep 2012, Fengguang Wu wrote:

> commit: 55a6b9f968a877c728ed6e438fa68741a7711d89 [28/30] CK1 [12/13] Common names for the array of kmalloc caches

Is this issue really caused by the specified commit? I do not see how the
patch can cause such a problem.

Re: [glommer-memcg:slab-common/kmalloc 28/30] include/linux/slab_def.h:135:27: warning: array subscr

[Fengguang Wu]

On Fri, Sep 28, 2012 at 06:17:20PM +0000, Christoph Lameter wrote:
> On Fri, 28 Sep 2012, Fengguang Wu wrote:
> 
> > commit: 55a6b9f968a877c728ed6e438fa68741a7711d89 [28/30] CK1 [12/13] Common names for the array of kmalloc caches
> 
> Is this issue really caused by the specified commit? I do not see how the
> patch can cause such a problem.

It should be a wrong bisection. Sorry. I checked manually and find
that the previous commit stopped early at this error:

In file included from /c/kernel-tests/src/next/include/linux/slab.h:309:0,
                 from /c/kernel-tests/src/next/include/linux/proc_fs.h:4,
                 from /c/kernel-tests/src/next/fs/proc/stat.c:6:
/c/kernel-tests/src/next/include/linux/slab_def.h: In function 'kmalloc':
/c/kernel-tests/src/next/include/linux/slab_def.h:132:13: error: 'kmalloc_dma_caches' undeclared (first use in this function)
/c/kernel-tests/src/next/include/linux/slab_def.h:132:13: note: each undeclared identifier is reported only once for each function it appears in
/c/kernel-tests/src/next/include/linux/slab_def.h:135:13: error: 'kmalloc_caches' undeclared (first use in this function)

Thus the warning was "hide" until the current commit:

In file included from /c/kernel-tests/src/next/include/linux/slab.h:314:0,
                 from /c/kernel-tests/src/next/include/linux/proc_fs.h:4,
                 from /c/kernel-tests/src/next/fs/proc/stat.c:6:
/c/kernel-tests/src/next/fs/proc/stat.c: In function 'stat_open':
/c/kernel-tests/src/next/include/linux/slab_def.h:135:27: warning: array subscript is above array bounds [-Warray-bounds]

Thanks,
Fengguang

Re: [glommer-memcg:slab-common/kmalloc 28/30] include/linux/slab_def.h:135:27: warning: array subscr

[Christoph Lameter]

On Sat, 29 Sep 2012, Fengguang Wu wrote:

> On Fri, Sep 28, 2012 at 06:17:20PM +0000, Christoph Lameter wrote:
> > On Fri, 28 Sep 2012, Fengguang Wu wrote:
> >
> > > commit: 55a6b9f968a877c728ed6e438fa68741a7711d89 [28/30] CK1 [12/13] Common names for the array of kmalloc caches
> >
> > Is this issue really caused by the specified commit? I do not see how the
> > patch can cause such a problem.
>
> It should be a wrong bisection. Sorry. I checked manually and find
> that the previous commit stopped early at this error:
>
> In file included from /c/kernel-tests/src/next/include/linux/slab.h:309:0,
>                  from /c/kernel-tests/src/next/include/linux/proc_fs.h:4,
>                  from /c/kernel-tests/src/next/fs/proc/stat.c:6:
> /c/kernel-tests/src/next/include/linux/slab_def.h: In function 'kmalloc':
> /c/kernel-tests/src/next/include/linux/slab_def.h:132:13: error: 'kmalloc_dma_caches' undeclared (first use in this function)
> /c/kernel-tests/src/next/include/linux/slab_def.h:132:13: note: each undeclared identifier is reported only once for each function it appears in
> /c/kernel-tests/src/next/include/linux/slab_def.h:135:13: error: 'kmalloc_caches' undeclared (first use in this function)
>
> Thus the warning was "hide" until the current commit:
>
> In file included from /c/kernel-tests/src/next/include/linux/slab.h:314:0,
>                  from /c/kernel-tests/src/next/include/linux/proc_fs.h:4,
>                  from /c/kernel-tests/src/next/fs/proc/stat.c:6:
> /c/kernel-tests/src/next/fs/proc/stat.c: In function 'stat_open':
> /c/kernel-tests/src/next/include/linux/slab_def.h:135:27: warning: array subscript is above array bounds [-Warray-bounds]

Ok there were some fixes in that area in V2. Could we try again and see if
the new version fixes it?

Re: [glommer-memcg:slab-common/kmalloc 28/30] include/linux/slab_def.h:135:27: warning: array subscr

[Glauber Costa]

On 10/01/2012 09:55 PM, Christoph Lameter wrote:
> On Sat, 29 Sep 2012, Fengguang Wu wrote:
> 
>> On Fri, Sep 28, 2012 at 06:17:20PM +0000, Christoph Lameter wrote:
>>> On Fri, 28 Sep 2012, Fengguang Wu wrote:
>>>
>>>> commit: 55a6b9f968a877c728ed6e438fa68741a7711d89 [28/30] CK1 [12/13] Common names for the array of kmalloc caches
>>>
>>> Is this issue really caused by the specified commit? I do not see how the
>>> patch can cause such a problem.
>>
>> It should be a wrong bisection. Sorry. I checked manually and find
>> that the previous commit stopped early at this error:
>>
>> In file included from /c/kernel-tests/src/next/include/linux/slab.h:309:0,
>>                  from /c/kernel-tests/src/next/include/linux/proc_fs.h:4,
>>                  from /c/kernel-tests/src/next/fs/proc/stat.c:6:
>> /c/kernel-tests/src/next/include/linux/slab_def.h: In function 'kmalloc':
>> /c/kernel-tests/src/next/include/linux/slab_def.h:132:13: error: 'kmalloc_dma_caches' undeclared (first use in this function)
>> /c/kernel-tests/src/next/include/linux/slab_def.h:132:13: note: each undeclared identifier is reported only once for each function it appears in
>> /c/kernel-tests/src/next/include/linux/slab_def.h:135:13: error: 'kmalloc_caches' undeclared (first use in this function)
>>
>> Thus the warning was "hide" until the current commit:
>>
>> In file included from /c/kernel-tests/src/next/include/linux/slab.h:314:0,
>>                  from /c/kernel-tests/src/next/include/linux/proc_fs.h:4,
>>                  from /c/kernel-tests/src/next/fs/proc/stat.c:6:
>> /c/kernel-tests/src/next/fs/proc/stat.c: In function 'stat_open':
>> /c/kernel-tests/src/next/include/linux/slab_def.h:135:27: warning: array subscript is above array bounds [-Warray-bounds]
> 
> Ok there were some fixes in that area in V2. Could we try again and see if
> the new version fixes it?
> 
I plan to upload a version with your new patches shortly. Sorry, I am
trying to get a new version of my memcg-slab series with your feedback
incorporated as soon as I can, so I was a bit slow with review yesterday
in general.

Re: [glommer-memcg:slab-common/kmalloc 28/30] include/linux/slab_def.h:135:27: warning: array subscr

[Christoph Lameter]

On Tue, 2 Oct 2012, Glauber Costa wrote:

> I plan to upload a version with your new patches shortly. Sorry, I am
> trying to get a new version of my memcg-slab series with your feedback
> incorporated as soon as I can, so I was a bit slow with review yesterday
> in general.

Well looks things are moving already much faster then in the past. So do
not worry about small delays like that.