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* drivers/video/backlight/ltv350qv.c:192:12: warning: stack frame size of 13472 bytes in function 'ltv350qv_power'
@ 2020-10-25 18:15 kernel test robot
  2020-10-25 19:17 ` Andrew Morton
  0 siblings, 1 reply; 6+ messages in thread
From: kernel test robot @ 2020-10-25 18:15 UTC (permalink / raw)
  To: Andrey Konovalov
  Cc: kbuild-all, clang-built-linux, linux-kernel, Andrew Morton,
	Linux Memory Management List

[-- Attachment #1: Type: text/plain, Size: 3120 bytes --]

tree:   https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master
head:   d76913908102044f14381df865bb74df17a538cb
commit: cae9dc35ed9ff82a99754e51d57ff6c332e1f7e4 kasan: allow enabling stack tagging for tag-based mode
date:   3 months ago
config: arm64-randconfig-r005-20201026 (attached as .config)
compiler: clang version 12.0.0 (https://github.com/llvm/llvm-project 1c8371692dfe8245bc6690ff1262dcced4649d21)
reproduce (this is a W=1 build):
        wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
        chmod +x ~/bin/make.cross
        # install arm64 cross compiling tool for clang build
        # apt-get install binutils-aarch64-linux-gnu
        # https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=cae9dc35ed9ff82a99754e51d57ff6c332e1f7e4
        git remote add linus https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
        git fetch --no-tags linus master
        git checkout cae9dc35ed9ff82a99754e51d57ff6c332e1f7e4
        # save the attached .config to linux build tree
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross ARCH=arm64 

If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <lkp@intel.com>

All warnings (new ones prefixed by >>):

>> drivers/video/backlight/ltv350qv.c:192:12: warning: stack frame size of 13472 bytes in function 'ltv350qv_power' [-Wframe-larger-than=]
   static int ltv350qv_power(struct ltv350qv *lcd, int power)
              ^
   1 warning generated.

vim +/ltv350qv_power +192 drivers/video/backlight/ltv350qv.c

18f65c793a5106 Haavard Skinnemoen 2007-09-02  191  
18f65c793a5106 Haavard Skinnemoen 2007-09-02 @192  static int ltv350qv_power(struct ltv350qv *lcd, int power)
18f65c793a5106 Haavard Skinnemoen 2007-09-02  193  {
18f65c793a5106 Haavard Skinnemoen 2007-09-02  194  	int ret = 0;
18f65c793a5106 Haavard Skinnemoen 2007-09-02  195  
18f65c793a5106 Haavard Skinnemoen 2007-09-02  196  	if (POWER_IS_ON(power) && !POWER_IS_ON(lcd->power))
18f65c793a5106 Haavard Skinnemoen 2007-09-02  197  		ret = ltv350qv_power_on(lcd);
18f65c793a5106 Haavard Skinnemoen 2007-09-02  198  	else if (!POWER_IS_ON(power) && POWER_IS_ON(lcd->power))
18f65c793a5106 Haavard Skinnemoen 2007-09-02  199  		ret = ltv350qv_power_off(lcd);
18f65c793a5106 Haavard Skinnemoen 2007-09-02  200  
18f65c793a5106 Haavard Skinnemoen 2007-09-02  201  	if (!ret)
18f65c793a5106 Haavard Skinnemoen 2007-09-02  202  		lcd->power = power;
18f65c793a5106 Haavard Skinnemoen 2007-09-02  203  
18f65c793a5106 Haavard Skinnemoen 2007-09-02  204  	return ret;
18f65c793a5106 Haavard Skinnemoen 2007-09-02  205  }
18f65c793a5106 Haavard Skinnemoen 2007-09-02  206  

:::::: The code at line 192 was first introduced by commit
:::::: 18f65c793a5106b9f99822ef248e71582db03386 backlight: Add Samsung LTV350QV LCD driver

:::::: TO: Haavard Skinnemoen <hskinnemoen@atmel.com>
:::::: CC: Richard Purdie <rpurdie@rpsys.net>

---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org

[-- Attachment #2: .config.gz --]
[-- Type: application/gzip, Size: 34821 bytes --]

^ permalink raw reply	[flat|nested] 6+ messages in thread
* Re: drivers/video/backlight/ltv350qv.c:192:12: warning: stack frame size of 13472 bytes in function 'ltv350qv_power'
  2020-10-25 18:15 drivers/video/backlight/ltv350qv.c:192:12: warning: stack frame size of 13472 bytes in function 'ltv350qv_power' kernel test robot
@ 2020-10-25 19:17 ` Andrew Morton
  2020-10-25 19:23   ` Joe Perches
                     ` (2 more replies)
  0 siblings, 3 replies; 6+ messages in thread
From: Andrew Morton @ 2020-10-25 19:17 UTC (permalink / raw)
  To: kernel test robot
  Cc: Andrey Konovalov, kbuild-all, clang-built-linux, linux-kernel,
	Linux Memory Management List

On Mon, 26 Oct 2020 02:15:37 +0800 kernel test robot <lkp@intel.com> wrote:

> tree:   https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master
> head:   d76913908102044f14381df865bb74df17a538cb
> commit: cae9dc35ed9ff82a99754e51d57ff6c332e1f7e4 kasan: allow enabling stack tagging for tag-based mode
> date:   3 months ago
> config: arm64-randconfig-r005-20201026 (attached as .config)
> compiler: clang version 12.0.0 (https://github.com/llvm/llvm-project 1c8371692dfe8245bc6690ff1262dcced4649d21)
> reproduce (this is a W=1 build):
>         wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
>         chmod +x ~/bin/make.cross
>         # install arm64 cross compiling tool for clang build
>         # apt-get install binutils-aarch64-linux-gnu
>         # https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=cae9dc35ed9ff82a99754e51d57ff6c332e1f7e4
>         git remote add linus https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
>         git fetch --no-tags linus master
>         git checkout cae9dc35ed9ff82a99754e51d57ff6c332e1f7e4
>         # save the attached .config to linux build tree
>         COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross ARCH=arm64 
> 
> If you fix the issue, kindly add following tag as appropriate
> Reported-by: kernel test robot <lkp@intel.com>
> 
> All warnings (new ones prefixed by >>):
> 
> >> drivers/video/backlight/ltv350qv.c:192:12: warning: stack frame size of 13472 bytes in function 'ltv350qv_power' [-Wframe-larger-than=]

That's a lot of stack.

>    static int ltv350qv_power(struct ltv350qv *lcd, int power)
>               ^
>    1 warning generated.
> 
> vim +/ltv350qv_power +192 drivers/video/backlight/ltv350qv.c

Odd - the code looks pretty normal.  It is possible that your compiler
is (crazily) inlining ltv350qv_write_reg()?

^ permalink raw reply	[flat|nested] 6+ messages in thread
* Re: drivers/video/backlight/ltv350qv.c:192:12: warning: stack frame size of 13472 bytes in function 'ltv350qv_power'
  2020-10-25 19:17 ` Andrew Morton
@ 2020-10-25 19:23   ` Joe Perches
  2020-10-28 15:46   ` Daniel Thompson
  2020-10-29 15:28   ` Andrey Konovalov
  2 siblings, 0 replies; 6+ messages in thread
From: Joe Perches @ 2020-10-25 19:23 UTC (permalink / raw)
  To: Andrew Morton, kernel test robot
  Cc: Andrey Konovalov, kbuild-all, clang-built-linux, linux-kernel,
	Linux Memory Management List

On Sun, 2020-10-25 at 12:17 -0700, Andrew Morton wrote:
> On Mon, 26 Oct 2020 02:15:37 +0800 kernel test robot <lkp@intel.com> wrote:
> > vim +/ltv350qv_power +192 drivers/video/backlight/ltv350qv.c
> 
> Odd - the code looks pretty normal.  It is possible that your compiler
> is (crazily) inlining ltv350qv_write_reg()?

There's a lot of stack used when gcc's compiler options include

           -fsanitize=object-size
               This option enables instrumentation of memory references using
               the "__builtin_object_size" function.  Various out of bounds
               pointer accesses are detected.

Perhaps this config enables it?



^ permalink raw reply	[flat|nested] 6+ messages in thread
* Re: drivers/video/backlight/ltv350qv.c:192:12: warning: stack frame size of 13472 bytes in function 'ltv350qv_power'
  2020-10-25 19:17 ` Andrew Morton
  2020-10-25 19:23   ` Joe Perches
@ 2020-10-28 15:46   ` Daniel Thompson
  2020-10-29 15:28   ` Andrey Konovalov
  2 siblings, 0 replies; 6+ messages in thread
From: Daniel Thompson @ 2020-10-28 15:46 UTC (permalink / raw)
  To: Andrew Morton
  Cc: kernel test robot, Andrey Konovalov, kbuild-all,
	clang-built-linux, linux-kernel, Linux Memory Management List

On Sun, Oct 25, 2020 at 12:17:08PM -0700, Andrew Morton wrote:
> On Mon, 26 Oct 2020 02:15:37 +0800 kernel test robot <lkp@intel.com> wrote:
> 
> > tree:   https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master
> > head:   d76913908102044f14381df865bb74df17a538cb
> > commit: cae9dc35ed9ff82a99754e51d57ff6c332e1f7e4 kasan: allow enabling stack tagging for tag-based mode
> > date:   3 months ago
> > config: arm64-randconfig-r005-20201026 (attached as .config)
> > compiler: clang version 12.0.0 (https://github.com/llvm/llvm-project 1c8371692dfe8245bc6690ff1262dcced4649d21)
> > reproduce (this is a W=1 build):
> >         wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
> >         chmod +x ~/bin/make.cross
> >         # install arm64 cross compiling tool for clang build
> >         # apt-get install binutils-aarch64-linux-gnu
> >         # https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=cae9dc35ed9ff82a99754e51d57ff6c332e1f7e4
> >         git remote add linus https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
> >         git fetch --no-tags linus master
> >         git checkout cae9dc35ed9ff82a99754e51d57ff6c332e1f7e4
> >         # save the attached .config to linux build tree
> >         COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross ARCH=arm64 
> > 
> > If you fix the issue, kindly add following tag as appropriate
> > Reported-by: kernel test robot <lkp@intel.com>
> > 
> > All warnings (new ones prefixed by >>):
> > 
> > >> drivers/video/backlight/ltv350qv.c:192:12: warning: stack frame size of 13472 bytes in function 'ltv350qv_power' [-Wframe-larger-than=]
> 
> That's a lot of stack.
> 
> >    static int ltv350qv_power(struct ltv350qv *lcd, int power)
> >               ^
> >    1 warning generated.
> > 
> > vim +/ltv350qv_power +192 drivers/video/backlight/ltv350qv.c
> 
> Odd - the code looks pretty normal.  It is possible that your compiler
> is (crazily) inlining ltv350qv_write_reg()?

Certainly could be.

Same config compiled with gcc-9 gives ltv350qv_write_reg() a stack usage
that is large but not crazy: 768 bytes and dropping to 480 bytes with
the sanitizers disabled. With the sanitizers enabled then even the 
cumulative stack usage of ltv350qv_power() through to ltv350qv_write_reg() is
still less than 1k.


Daniel.

^ permalink raw reply	[flat|nested] 6+ messages in thread
* Re: drivers/video/backlight/ltv350qv.c:192:12: warning: stack frame size of 13472 bytes in function 'ltv350qv_power'
  2020-10-25 19:17 ` Andrew Morton
  2020-10-25 19:23   ` Joe Perches
  2020-10-28 15:46   ` Daniel Thompson
@ 2020-10-29 15:28   ` Andrey Konovalov
  2020-10-30 13:28     ` [kbuild-all] " Chen, Rong A
  2 siblings, 1 reply; 6+ messages in thread
From: Andrey Konovalov @ 2020-10-29 15:28 UTC (permalink / raw)
  To: Andrew Morton, kernel test robot
  Cc: kbuild-all, clang-built-linux, LKML,
	Linux Memory Management List, Arnd Bergmann

On Sun, Oct 25, 2020 at 8:17 PM Andrew Morton <akpm@linux-foundation.org> wrote:
>
> On Mon, 26 Oct 2020 02:15:37 +0800 kernel test robot <lkp@intel.com> wrote:
>
> > tree:   https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master
> > head:   d76913908102044f14381df865bb74df17a538cb
> > commit: cae9dc35ed9ff82a99754e51d57ff6c332e1f7e4 kasan: allow enabling stack tagging for tag-based mode
> > date:   3 months ago
> > config: arm64-randconfig-r005-20201026 (attached as .config)
> > compiler: clang version 12.0.0 (https://github.com/llvm/llvm-project 1c8371692dfe8245bc6690ff1262dcced4649d21)
> > reproduce (this is a W=1 build):
> >         wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
> >         chmod +x ~/bin/make.cross
> >         # install arm64 cross compiling tool for clang build
> >         # apt-get install binutils-aarch64-linux-gnu
> >         # https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=cae9dc35ed9ff82a99754e51d57ff6c332e1f7e4
> >         git remote add linus https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
> >         git fetch --no-tags linus master
> >         git checkout cae9dc35ed9ff82a99754e51d57ff6c332e1f7e4
> >         # save the attached .config to linux build tree
> >         COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross ARCH=arm64
> >
> > If you fix the issue, kindly add following tag as appropriate
> > Reported-by: kernel test robot <lkp@intel.com>
> >
> > All warnings (new ones prefixed by >>):
> >
> > >> drivers/video/backlight/ltv350qv.c:192:12: warning: stack frame size of 13472 bytes in function 'ltv350qv_power' [-Wframe-larger-than=]
>
> That's a lot of stack.
>
> >    static int ltv350qv_power(struct ltv350qv *lcd, int power)
> >               ^
> >    1 warning generated.
> >
> > vim +/ltv350qv_power +192 drivers/video/backlight/ltv350qv.c
>
> Odd - the code looks pretty normal.  It is possible that your compiler
> is (crazily) inlining ltv350qv_write_reg()?

This is the same issue in LLVM that was reported by Arnd for generic
KASAN (also see KASAN_STACK_ENABLE option description). By default
KASAN shouldn't have stack instrumentation enabled unless
KASAN_STACK_ENABLE is specified. Perhaps it makes sense to disable it
for KASAN_SW_TAGS config on the kernel test robot.

[1] https://bugs.llvm.org/show_bug.cgi?id=38809

^ permalink raw reply	[flat|nested] 6+ messages in thread
* Re: [kbuild-all] Re: drivers/video/backlight/ltv350qv.c:192:12: warning: stack frame size of 13472 bytes in function 'ltv350qv_power'
  2020-10-29 15:28   ` Andrey Konovalov
@ 2020-10-30 13:28     ` Chen, Rong A
  0 siblings, 0 replies; 6+ messages in thread
From: Chen, Rong A @ 2020-10-30 13:28 UTC (permalink / raw)
  To: Andrey Konovalov, Andrew Morton, kernel test robot
  Cc: kbuild-all, clang-built-linux, LKML,
	Linux Memory Management List, Arnd Bergmann



On 10/29/2020 11:28 PM, Andrey Konovalov wrote:
> On Sun, Oct 25, 2020 at 8:17 PM Andrew Morton <akpm@linux-foundation.org> wrote:
>>
>> On Mon, 26 Oct 2020 02:15:37 +0800 kernel test robot <lkp@intel.com> wrote:
>>
>>> tree:   https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master
>>> head:   d76913908102044f14381df865bb74df17a538cb
>>> commit: cae9dc35ed9ff82a99754e51d57ff6c332e1f7e4 kasan: allow enabling stack tagging for tag-based mode
>>> date:   3 months ago
>>> config: arm64-randconfig-r005-20201026 (attached as .config)
>>> compiler: clang version 12.0.0 (https://github.com/llvm/llvm-project 1c8371692dfe8245bc6690ff1262dcced4649d21)
>>> reproduce (this is a W=1 build):
>>>          wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
>>>          chmod +x ~/bin/make.cross
>>>          # install arm64 cross compiling tool for clang build
>>>          # apt-get install binutils-aarch64-linux-gnu
>>>          # https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=cae9dc35ed9ff82a99754e51d57ff6c332e1f7e4
>>>          git remote add linus https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
>>>          git fetch --no-tags linus master
>>>          git checkout cae9dc35ed9ff82a99754e51d57ff6c332e1f7e4
>>>          # save the attached .config to linux build tree
>>>          COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross ARCH=arm64
>>>
>>> If you fix the issue, kindly add following tag as appropriate
>>> Reported-by: kernel test robot <lkp@intel.com>
>>>
>>> All warnings (new ones prefixed by >>):
>>>
>>>>> drivers/video/backlight/ltv350qv.c:192:12: warning: stack frame size of 13472 bytes in function 'ltv350qv_power' [-Wframe-larger-than=]
>>
>> That's a lot of stack.
>>
>>>     static int ltv350qv_power(struct ltv350qv *lcd, int power)
>>>                ^
>>>     1 warning generated.
>>>
>>> vim +/ltv350qv_power +192 drivers/video/backlight/ltv350qv.c
>>
>> Odd - the code looks pretty normal.  It is possible that your compiler
>> is (crazily) inlining ltv350qv_write_reg()?
> 
> This is the same issue in LLVM that was reported by Arnd for generic
> KASAN (also see KASAN_STACK_ENABLE option description). By default
> KASAN shouldn't have stack instrumentation enabled unless
> KASAN_STACK_ENABLE is specified. Perhaps it makes sense to disable it
> for KASAN_SW_TAGS config on the kernel test robot.

Hi Andrey,

Thanks for your advice, we'll take a look.

Best Regards,
Rong Chen

> 
> [1] https://bugs.llvm.org/show_bug.cgi?id=38809
> _______________________________________________
> kbuild-all mailing list -- kbuild-all@lists.01.org
> To unsubscribe send an email to kbuild-all-leave@lists.01.org
> 

^ permalink raw reply	[flat|nested] 6+ messages in thread
end of thread, other threads:[~2020-10-30 13:28 UTC | newest]

Thread overview: 6+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2020-10-25 18:15 drivers/video/backlight/ltv350qv.c:192:12: warning: stack frame size of 13472 bytes in function 'ltv350qv_power' kernel test robot
2020-10-25 19:17 ` Andrew Morton
2020-10-25 19:23   ` Joe Perches
2020-10-28 15:46   ` Daniel Thompson
2020-10-29 15:28   ` Andrey Konovalov
2020-10-30 13:28     ` [kbuild-all] " Chen, Rong A

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