From 313146a844182c4829acd5e1d60246367212088f Mon Sep 17 00:00:00 2001 From: Thomas Richter Date: Tue, 25 Aug 2020 08:33:04 +0200 Subject: [PATCH] perf stat: Fix out of bounds array access in the print_counters() evlist method MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Fix a compile error on F32 and gcc version 10.1 on s390 in file utils/stat-display.c. The error does not show up with make DEBUG=y. In fact the issue shows up when using both compiler options -O6 and -D_FORTIFY_SOURCE=2 (which are omitted with DEBUG=Y). This is the offending call chain: print_counter_aggr() printout(config, -1, 0, ...) with 2nd parm id set to -1 aggr_printout(config, x, id --> -1, ...) which leads to this code: case AGGR_NONE: if (evsel->percore && !config->percore_show_thread) { .... } else { fprintf(config->output, "CPU%*d%s", config->csv_output ? 0 : -7, evsel__cpus(evsel)->map[id], ^^ id is -1 !!!! config->csv_sep); } This is a compiler inlining issue which is detected on s390 but not on other plattforms. Output before: # make util/stat-display.o ..... util/stat-display.c: In function ‘perf_evlist__print_counters’: util/stat-display.c:121:4: error: array subscript -1 is below array bounds of ‘int[]’ [-Werror=array-bounds] 121 | fprintf(config->output, "CPU%*d%s", | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ 122 | config->csv_output ? 0 : -7, | ~~~~~~~~~~~~~~~~~~~~~~~~~~~~ 123 | evsel__cpus(evsel)->map[id], | ~~~~~~~~~~~~~~~~~~~~~~~~~~~~ 124 | config->csv_sep); | ~~~~~~~~~~~~~~~~ In file included from util/evsel.h:13, from util/evlist.h:13, from util/stat-display.c:9: /root/linux/tools/lib/perf/include/internal/cpumap.h:10:7: note: while referencing ‘map’ 10 | int map[]; | ^~~ cc1: all warnings being treated as errors mv: cannot stat 'util/.stat-display.o.tmp': No such file or directory make[3]: *** [/root/linux/tools/build/Makefile.build:97: util/stat-display.o] Error 1 make[2]: *** [Makefile.perf:716: util/stat-display.o] Error 2 make[1]: *** [Makefile.perf:231: sub-make] Error 2 make: *** [Makefile:110: util/stat-display.o] Error 2 [root@t35lp46 perf]# Output after: # make util/stat-display.o ..... CC util/stat-display.o [root@t35lp46 perf]# Committer notes: Removed the removal of {} enclosing the multiline else block, as pointed out by Jiri Olsa. Suggested-by: Jiri Olsa Signed-off-by: Thomas Richter Acked-by: Jiri Olsa Cc: Heiko Carstens Cc: Sumanth Korikkar Cc: Sven Schnelle Cc: Vasily Gorbik Link: http://lore.kernel.org/lkml/20200825063304.77733-1-tmricht@linux.ibm.com Signed-off-by: Arnaldo Carvalho de Melo --- tools/perf/util/stat-display.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/tools/perf/util/stat-display.c b/tools/perf/util/stat-display.c index 57d0706e1330..493ec372fdec 100644 --- a/tools/perf/util/stat-display.c +++ b/tools/perf/util/stat-display.c @@ -117,7 +117,7 @@ static void aggr_printout(struct perf_stat_config *config, cpu_map__id_to_die(id), config->csv_output ? 0 : -3, cpu_map__id_to_cpu(id), config->csv_sep); - } else { + } else if (id > -1) { fprintf(config->output, "CPU%*d%s", config->csv_output ? 0 : -7, evsel__cpus(evsel)->map[id],