Re: [PATCH v5] perf tools: Fix arm64 build error with gcc-11

John Garry <john.garry@xxxxxxxxxx> · Thu, 18 Feb 2021 09:26:17 +0000

On 18/02/2021 03:12, Jianlin Lv wrote:
gcc version: 11.0.0 20210208 (experimental) (GCC)

Following build error on arm64:

.......
In function ‘printf’,
     inlined from ‘regs_dump__printf’ at util/session.c:1141:3,
     inlined from ‘regs__printf’ at util/session.c:1169:2:
/usr/include/aarch64-linux-gnu/bits/stdio2.h:107:10: \
   error: ‘%-5s’ directive argument is null [-Werror=format-overflow=]

107 |   return __printf_chk (__USE_FORTIFY_LEVEL - 1, __fmt, \
                 __va_arg_pack ());

......
In function ‘fprintf’,
   inlined from ‘perf_sample__fprintf_regs.isra’ at \
     builtin-script.c:622:14:
/usr/include/aarch64-linux-gnu/bits/stdio2.h:100:10: \
     error: ‘%5s’ directive argument is null [-Werror=format-overflow=]
   100 |   return __fprintf_chk (__stream, __USE_FORTIFY_LEVEL - 1, __fmt,
   101 |                         __va_arg_pack ());

cc1: all warnings being treated as errors
.......

This patch fixes Wformat-overflow warnings. Add helper function to
convert NULL to "unknown".

Signed-off-by: Jianlin Lv<Jianlin.Lv@xxxxxxx>

thanks
Reviewed-by: John Garry <john.garry@xxxxxxxxxx>