[ Upstream commit 97acec7df172cd1e450f81f5e293c0aa145a2797 ]
This strncat() is safe because the buffer was allocated with zalloc(), however gcc doesn't know that. Since the string always has 4 non-null bytes, just use memcpy() here.
CC /home/shawn/linux/tools/perf/util/data-convert-bt.o In file included from /usr/include/string.h:494, from /home/shawn/linux/tools/lib/traceevent/event-parse.h:27, from util/data-convert-bt.c:22: In function ‘strncat’, inlined from ‘string_set_value’ at util/data-convert-bt.c:274:4: /usr/include/powerpc64le-linux-gnu/bits/string_fortified.h:136:10: error: ‘__builtin_strncat’ output may be truncated copying 4 bytes from a string of length 4 [-Werror=stringop-truncation] 136 | return __builtin___strncat_chk (__dest, __src, __len, __bos (__dest)); | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Signed-off-by: Shawn Landden shawn@git.icu Cc: Adrian Hunter adrian.hunter@intel.com Cc: Jiri Olsa jolsa@redhat.com Cc: Namhyung Kim namhyung@kernel.org Cc: Wang Nan wangnan0@huawei.com LPU-Reference: 20190518183238.10954-1-shawn@git.icu Link: https://lkml.kernel.org/n/tip-289f1jice17ta7tr3tstm9jm@git.kernel.org Signed-off-by: Arnaldo Carvalho de Melo acme@redhat.com Signed-off-by: Sasha Levin sashal@kernel.org --- tools/perf/util/data-convert-bt.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/tools/perf/util/data-convert-bt.c b/tools/perf/util/data-convert-bt.c index 7123f4de32cc..226f4312b8f3 100644 --- a/tools/perf/util/data-convert-bt.c +++ b/tools/perf/util/data-convert-bt.c @@ -265,7 +265,7 @@ static int string_set_value(struct bt_ctf_field *field, const char *string) if (i > 0) strncpy(buffer, string, i); } - strncat(buffer + p, numstr, 4); + memcpy(buffer + p, numstr, 4); p += 3; } }