From: Jiri Olsa jolsa@redhat.com
[ Upstream commit 279ab04dbea1370d2eac0f854270369ccaef8a44 ]
We are getting false positive gcc warning when we compile with gcc9 (9.1.1):
CC jvmti/libjvmti.o In file included from /usr/include/string.h:494, from jvmti/libjvmti.c:5: In function ‘strncpy’, inlined from ‘copy_class_filename.constprop’ at jvmti/libjvmti.c:166:3: /usr/include/bits/string_fortified.h:106:10: error: ‘__builtin_strncpy’ specified bound depends on the length of the source argument [-Werror=stringop-overflow=] 106 | return __builtin___strncpy_chk (__dest, __src, __len, __bos (__dest)); | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ jvmti/libjvmti.c: In function ‘copy_class_filename.constprop’: jvmti/libjvmti.c:165:26: note: length computed here 165 | size_t file_name_len = strlen(file_name); | ^~~~~~~~~~~~~~~~~ cc1: all warnings being treated as errors
As per Arnaldo's suggestion use strlcpy(), which does the same thing and keeps gcc silent.
Suggested-by: Arnaldo Carvalho de Melo acme@redhat.com Signed-off-by: Jiri Olsa jolsa@kernel.org Cc: Alexander Shishkin alexander.shishkin@linux.intel.com Cc: Ben Gainey ben.gainey@arm.com Cc: Namhyung Kim namhyung@kernel.org Cc: Peter Zijlstra peterz@infradead.org Cc: Stephane Eranian eranian@google.com Link: http://lkml.kernel.org/r/20190531131321.GB1281@krava Signed-off-by: Arnaldo Carvalho de Melo acme@redhat.com Signed-off-by: Sasha Levin sashal@kernel.org --- tools/perf/jvmti/libjvmti.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/tools/perf/jvmti/libjvmti.c b/tools/perf/jvmti/libjvmti.c index aea7b1fe85aa..c441a34cb1c0 100644 --- a/tools/perf/jvmti/libjvmti.c +++ b/tools/perf/jvmti/libjvmti.c @@ -1,5 +1,6 @@ // SPDX-License-Identifier: GPL-2.0 #include <linux/compiler.h> +#include <linux/string.h> #include <sys/types.h> #include <stdio.h> #include <string.h> @@ -162,8 +163,7 @@ copy_class_filename(const char * class_sign, const char * file_name, char * resu result[i] = '\0'; } else { /* fallback case */ - size_t file_name_len = strlen(file_name); - strncpy(result, file_name, file_name_len < max_length ? file_name_len : max_length); + strlcpy(result, file_name, max_length); } }