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* lib/test_scanf.c:531:1: warning: the frame size of 2080 bytes is larger than 2048 bytes
@ 2021-07-13  8:21 kernel test robot
  2021-07-23 16:15 ` Richard Fitzgerald
  0 siblings, 1 reply; 3+ messages in thread
From: kernel test robot @ 2021-07-13  8:21 UTC (permalink / raw)
  To: Richard Fitzgerald; +Cc: kbuild-all, linux-kernel, Petr Mladek

[-- Attachment #1: Type: text/plain, Size: 4693 bytes --]

tree:   https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master
head:   7fef2edf7cc753b51f7ccc74993971b0a9c81eca
commit: 50f530e176eac808e64416732e54c0686ce2c39b lib: test_scanf: Add tests for sscanf number conversion
date:   8 weeks ago
config: arm-randconfig-r001-20210713 (attached as .config)
compiler: arm-linux-gnueabi-gcc (GCC) 9.3.0
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
        # https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=50f530e176eac808e64416732e54c0686ce2c39b
        git remote add linus https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
        git fetch --no-tags linus master
        git checkout 50f530e176eac808e64416732e54c0686ce2c39b
        # save the attached .config to linux build tree
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-9.3.0 make.cross ARCH=arm 

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 >>):

   lib/test_scanf.c: In function 'numbers_list_field_width_val_width':
>> lib/test_scanf.c:531:1: warning: the frame size of 2080 bytes is larger than 2048 bytes [-Wframe-larger-than=]
     531 | }
         | ^
   lib/test_scanf.c: In function 'numbers_list_field_width_typemax':
   lib/test_scanf.c:489:1: warning: the frame size of 2552 bytes is larger than 2048 bytes [-Wframe-larger-than=]
     489 | }
         | ^
   lib/test_scanf.c: In function 'numbers_list':
   lib/test_scanf.c:438:1: warning: the frame size of 2080 bytes is larger than 2048 bytes [-Wframe-larger-than=]
     438 | }
         | ^


vim +531 lib/test_scanf.c

   490	
   491	/*
   492	 * List of numbers separated by delim. Each field width specifier is the
   493	 * exact length of the corresponding value digits in the string being scanned.
   494	 */
   495	static void __init numbers_list_field_width_val_width(const char *delim)
   496	{
   497		numbers_list_val_width(unsigned long long, "%llu",   delim, "llu", check_ull);
   498		numbers_list_val_width(long long,	   "%lld",   delim, "lld", check_ll);
   499		numbers_list_val_width(long long,	   "%lld",   delim, "lli", check_ll);
   500		numbers_list_val_width(unsigned long long, "%llx",   delim, "llx", check_ull);
   501		numbers_list_val_width(unsigned long long, "0x%llx", delim, "llx", check_ull);
   502		numbers_list_val_width(long long,	   "0x%llx", delim, "lli", check_ll);
   503	
   504		numbers_list_val_width(unsigned long,	"%lu",	     delim, "lu", check_ulong);
   505		numbers_list_val_width(long,		"%ld",	     delim, "ld", check_long);
   506		numbers_list_val_width(long,		"%ld",	     delim, "li", check_long);
   507		numbers_list_val_width(unsigned long,	"%lx",	     delim, "lx", check_ulong);
   508		numbers_list_val_width(unsigned long,	"0x%lx",     delim, "lx", check_ulong);
   509		numbers_list_val_width(long,		"0x%lx",     delim, "li", check_long);
   510	
   511		numbers_list_val_width(unsigned int,	"%u",	     delim, "u", check_uint);
   512		numbers_list_val_width(int,		"%d",	     delim, "d", check_int);
   513		numbers_list_val_width(int,		"%d",	     delim, "i", check_int);
   514		numbers_list_val_width(unsigned int,	"%x",	     delim, "x", check_uint);
   515		numbers_list_val_width(unsigned int,	"0x%x",	     delim, "x", check_uint);
   516		numbers_list_val_width(int,		"0x%x",	     delim, "i", check_int);
   517	
   518		numbers_list_val_width(unsigned short,	"%hu",	     delim, "hu", check_ushort);
   519		numbers_list_val_width(short,		"%hd",	     delim, "hd", check_short);
   520		numbers_list_val_width(short,		"%hd",	     delim, "hi", check_short);
   521		numbers_list_val_width(unsigned short,	"%hx",	     delim, "hx", check_ushort);
   522		numbers_list_val_width(unsigned short,	"0x%hx",     delim, "hx", check_ushort);
   523		numbers_list_val_width(short,		"0x%hx",     delim, "hi", check_short);
   524	
   525		numbers_list_val_width(unsigned char,	"%hhu",	     delim, "hhu", check_uchar);
   526		numbers_list_val_width(signed char,	"%hhd",	     delim, "hhd", check_char);
   527		numbers_list_val_width(signed char,	"%hhd",	     delim, "hhi", check_char);
   528		numbers_list_val_width(unsigned char,	"%hhx",	     delim, "hhx", check_uchar);
   529		numbers_list_val_width(unsigned char,	"0x%hhx",    delim, "hhx", check_uchar);
   530		numbers_list_val_width(signed char,	"0x%hhx",    delim, "hhi", check_char);
 > 531	}
   532	

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

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^ permalink raw reply	[flat|nested] 3+ messages in thread
* Re: lib/test_scanf.c:531:1: warning: the frame size of 2080 bytes is larger than 2048 bytes
  2021-07-13  8:21 lib/test_scanf.c:531:1: warning: the frame size of 2080 bytes is larger than 2048 bytes kernel test robot
@ 2021-07-23 16:15 ` Richard Fitzgerald
  2021-07-27  9:01   ` [kbuild-all] " Chen, Rong A
  0 siblings, 1 reply; 3+ messages in thread
From: Richard Fitzgerald @ 2021-07-23 16:15 UTC (permalink / raw)
  To: Petr Mladek; +Cc: kbuild-all, linux-kernel, kernel test robot, -

On 13/07/2021 09:21, kernel test robot wrote:
> All warnings (new ones prefixed by >>):
> 
>     lib/test_scanf.c: In function 'numbers_list_field_width_val_width':
>>> lib/test_scanf.c:531:1: warning: the frame size of 2080 bytes is larger than 2048 bytes [-Wframe-larger-than=]
>       531 | }
>           | ^
>     lib/test_scanf.c: In function 'numbers_list_field_width_typemax':
>     lib/test_scanf.c:489:1: warning: the frame size of 2552 bytes is larger than 2048 bytes [-Wframe-larger-than=]
>       489 | }
>           | ^
>     lib/test_scanf.c: In function 'numbers_list':
>     lib/test_scanf.c:438:1: warning: the frame size of 2080 bytes is larger than 2048 bytes [-Wframe-larger-than=]
>       438 | }
>           | ^
> 

I haven't been able to reproduce this. I've tried these compilers:

Linaro AArch32 GCC 10.2.1 20201103(-O2 or -Os optimization): stack 
frames < 200 bytes

Linaro ARM32 7.5-2019.12 -Os: maximum of 384 bytes

Debian 6.3.0-18+deb9u1, x86_64 -O2: frames < 200 bytes

(The GCC fetched with the reproduction instructions from the krobot
report doesn't work on my Debian system.)

The sizes reported by the krobot are the total of all stack variable in
the function, but they all have limited scope. Obviously my GCC versions
are optimizing by effectively making a union of stack variable that are
used in different scope. So presumably the GCC version used by krobot is
missing this optimization. That feels to me more like a compiler bug if
it is allocating 12 times more stack than is actually necessary for the
function.

Output from my 10.2.1 compiler (-O2):

lib/test_scanf.c: In function 'numbers_list_field_width_val_width':
lib/test_scanf.c:530:1: warning: the frame size of 176 bytes is larger 
than 128 bytes [-Wframe-larger-than=]
   530 | }
       | ^
lib/test_scanf.c: In function 'numbers_list_field_width_typemax':
lib/test_scanf.c:488:1: warning: the frame size of 184 bytes is larger 
than 128 bytes [-Wframe-larger-than=]
   488 | }
       | ^
lib/test_scanf.c: In function 'numbers_list':
lib/test_scanf.c:437:1: warning: the frame size of 168 bytes is larger 
than 128 bytes [-Wframe-larger-than=]

^ permalink raw reply	[flat|nested] 3+ messages in thread
* Re: [kbuild-all] Re: lib/test_scanf.c:531:1: warning: the frame size of 2080 bytes is larger than 2048 bytes
  2021-07-23 16:15 ` Richard Fitzgerald
@ 2021-07-27  9:01   ` Chen, Rong A
  0 siblings, 0 replies; 3+ messages in thread
From: Chen, Rong A @ 2021-07-27  9:01 UTC (permalink / raw)
  To: Richard Fitzgerald, Petr Mladek
  Cc: kbuild-all, linux-kernel, kernel test robot, -



On 7/24/2021 12:15 AM, Richard Fitzgerald wrote:
> On 13/07/2021 09:21, kernel test robot wrote:
>> All warnings (new ones prefixed by >>):
>>
>>     lib/test_scanf.c: In function 'numbers_list_field_width_val_width':
>>>> lib/test_scanf.c:531:1: warning: the frame size of 2080 bytes is 
>>>> larger than 2048 bytes [-Wframe-larger-than=]
>>       531 | }
>>           | ^
>>     lib/test_scanf.c: In function 'numbers_list_field_width_typemax':
>>     lib/test_scanf.c:489:1: warning: the frame size of 2552 bytes is 
>> larger than 2048 bytes [-Wframe-larger-than=]
>>       489 | }
>>           | ^
>>     lib/test_scanf.c: In function 'numbers_list':
>>     lib/test_scanf.c:438:1: warning: the frame size of 2080 bytes is 
>> larger than 2048 bytes [-Wframe-larger-than=]
>>       438 | }
>>           | ^
>>
> 
> I haven't been able to reproduce this. I've tried these compilers:
> 
> Linaro AArch32 GCC 10.2.1 20201103(-O2 or -Os optimization): stack 
> frames < 200 bytes
> 
> Linaro ARM32 7.5-2019.12 -Os: maximum of 384 bytes
> 
> Debian 6.3.0-18+deb9u1, x86_64 -O2: frames < 200 bytes

Hi Richard,

I installed gcc-10-arm-linux-gnueabi on Debian and can't reproduce the 
warning too.

> 
> (The GCC fetched with the reproduction instructions from the krobot
> report doesn't work on my Debian system.)

I have confirmed that the gcc compiler used by the bot can reproduce the 
warning, which problem on your Debian system? we can improve the 
reproduce tool if there's more information.

Best Regards,
Rong Chen

> 
> The sizes reported by the krobot are the total of all stack variable in
> the function, but they all have limited scope. Obviously my GCC versions
> are optimizing by effectively making a union of stack variable that are
> used in different scope. So presumably the GCC version used by krobot is
> missing this optimization. That feels to me more like a compiler bug if
> it is allocating 12 times more stack than is actually necessary for the
> function.
> 
> Output from my 10.2.1 compiler (-O2):
> 
> lib/test_scanf.c: In function 'numbers_list_field_width_val_width':
> lib/test_scanf.c:530:1: warning: the frame size of 176 bytes is larger 
> than 128 bytes [-Wframe-larger-than=]
>    530 | }
>        | ^
> lib/test_scanf.c: In function 'numbers_list_field_width_typemax':
> lib/test_scanf.c:488:1: warning: the frame size of 184 bytes is larger 
> than 128 bytes [-Wframe-larger-than=]
>    488 | }
>        | ^
> lib/test_scanf.c: In function 'numbers_list':
> lib/test_scanf.c:437:1: warning: the frame size of 168 bytes is larger 
> than 128 bytes [-Wframe-larger-than=]
> _______________________________________________
> 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] 3+ messages in thread
end of thread, other threads:[~2021-07-27  9:01 UTC | newest]

Thread overview: 3+ messages (download: mbox.gz / follow: Atom feed)
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2021-07-13  8:21 lib/test_scanf.c:531:1: warning: the frame size of 2080 bytes is larger than 2048 bytes kernel test robot
2021-07-23 16:15 ` Richard Fitzgerald
2021-07-27  9:01   ` [kbuild-all] " Chen, Rong A

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