From d94d86cee1032bbf429d5bd0914b064e03b56f0e Mon Sep 17 00:00:00 2001 From: Athira Rajeev Date: Sun, 13 Oct 2024 23:07:42 +0530 Subject: [PATCH] tools/perf/tests: Fix compilation error with strncpy in tests/tool_pmu MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit perf fails to compile on systems with GCC version11 as below: In file included from /usr/include/string.h:519, from /home/athir/perf-tools-next/tools/include/linux/bitmap.h:5, from /home/athir/perf-tools-next/tools/perf/util/pmu.h:5, from /home/athir/perf-tools-next/tools/perf/util/evsel.h:14, from /home/athir/perf-tools-next/tools/perf/util/evlist.h:14, from tests/tool_pmu.c:3: In function ‘strncpy’, inlined from ‘do_test’ at tests/tool_pmu.c:25:3: /usr/include/bits/string_fortified.h:95:10: error: ‘__builtin_strncpy’ specified bound 128 equals destination size [-Werror=stringop-truncation] 95 | return __builtin___strncpy_chk (__dest, __src, __len, | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ 96 | __glibc_objsize (__dest)); | ~~~~~~~~~~~~~~~~~~~~~~~~~ The compile error is from strncpy refernce in do_test: strncpy(str, tool_pmu__event_to_str(ev), sizeof(str)); This behaviour is not observed with GCC version 8, but observed with GCC version 11 . This is message from gcc for detecting truncation while using strncpu. Use snprintf instead of strncpy here to be safe. Signed-off-by: Athira Rajeev Cc: akanksha@linux.ibm.com Cc: hbathini@linux.ibm.com Cc: kjain@linux.ibm.com Cc: maddy@linux.ibm.com Cc: disgoel@linux.vnet.ibm.com Cc: linuxppc-dev@lists.ozlabs.org Link: https://lore.kernel.org/r/20241013173742.71882-1-atrajeev@linux.vnet.ibm.com Signed-off-by: Namhyung Kim --- tools/perf/tests/tool_pmu.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/tools/perf/tests/tool_pmu.c b/tools/perf/tests/tool_pmu.c index 94d0dd8fd3cb..297cc8c55579 100644 --- a/tools/perf/tests/tool_pmu.c +++ b/tools/perf/tests/tool_pmu.c @@ -22,7 +22,7 @@ static int do_test(enum tool_pmu_event ev, bool with_pmu) if (with_pmu) snprintf(str, sizeof(str), "tool/%s/", tool_pmu__event_to_str(ev)); else - strncpy(str, tool_pmu__event_to_str(ev), sizeof(str)); + snprintf(str, sizeof(str), "%s", tool_pmu__event_to_str(ev)); parse_events_error__init(&err); ret = parse_events(evlist, str, &err);