> On 14 Sep 2021, at 11:27 AM, sunyucong@xxxxxxxxx wrote:
>
>> +static int poke_kprobe_events(bool add, const char *name, bool retprobe, uint64_t offset)
>> +{
>> + int fd, ret = 0;
>
> This patch introduced a warning/error in CI
>
> libbpf.c: In function ‘poke_kprobe_events’:
> 648 libbpf.c:9063:37: error: ‘%s’ directive output may be truncated
> writing up to 127 bytes into a region of size between 62 and 189
> [-Werror=format-truncation=]
> 649 9063 | snprintf(cmd, sizeof(cmd), "%c:%s %s",
> 650 | ^~
> 651 In file included from /usr/include/stdio.h:867,
> 652 from libbpf.c:17:
> 653 /usr/include/x86_64-linux-gnu/bits/stdio2.h:67:10: note:
> ‘__builtin___snprintf_chk’ output between 4 and 258 bytes into a
> destination of size 192
> 654 67 | return __builtin___snprintf_chk (__s, __n, __USE_FORTIFY_LEVEL - 1,
> 655 | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> 656 68 | __bos (__s), __fmt, __va_arg_pack ());
> 657 | ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
That happened because:
+ char cmd[192] = {}, probename[128] = {}, probefunc[128] = {};
was changed from original patch without initializing those to '\0' instead.
