From: Christophe JAILLET <christophe.jaillet@wanadoo.fr> stable inclusion from linux-4.19.149 commit 9a1d2d2eadeb4886610c2c310c8f39d106608e17 -------------------------------- [ Upstream commit d74b181a028bb5a468f0c609553eff6a8fdf4887 ] 'snprintf' returns the number of characters which would be generated for the given input. If the returned value is *greater than* or equal to the buffer size, it means that the output has been truncated. Fix the overflow test accordingly. Fixes: 7780c25bae59f ("perf tools: Allow ability to map cpus to nodes easily") Fixes: 92a7e1278005b ("perf cpumap: Add cpu__max_present_cpu()") Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr> Suggested-by: David Laight <David.Laight@ACULAB.COM> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Don Zickus <dzickus@redhat.com> Cc: He Zhe <zhe.he@windriver.com> Cc: Jan Stancek <jstancek@redhat.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Kan Liang <kan.liang@linux.intel.com> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: kernel-janitors@vger.kernel.org Link: http://lore.kernel.org/lkml/20200324070319.10901-1-christophe.jaillet@wanado... Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com> Signed-off-by: Sasha Levin <sashal@kernel.org> Signed-off-by: Yang Yingliang <yangyingliang@huawei.com> --- tools/perf/util/cpumap.c | 10 +++++----- 1 file changed, 5 insertions(+), 5 deletions(-) diff --git a/tools/perf/util/cpumap.c b/tools/perf/util/cpumap.c index f93846edc1e0..827d844f4efb 100644 --- a/tools/perf/util/cpumap.c +++ b/tools/perf/util/cpumap.c @@ -462,7 +462,7 @@ static void set_max_cpu_num(void) /* get the highest possible cpu number for a sparse allocation */ ret = snprintf(path, PATH_MAX, "%s/devices/system/cpu/possible", mnt); - if (ret == PATH_MAX) { + if (ret >= PATH_MAX) { pr_err("sysfs path crossed PATH_MAX(%d) size\n", PATH_MAX); goto out; } @@ -473,7 +473,7 @@ static void set_max_cpu_num(void) /* get the highest present cpu number for a sparse allocation */ ret = snprintf(path, PATH_MAX, "%s/devices/system/cpu/present", mnt); - if (ret == PATH_MAX) { + if (ret >= PATH_MAX) { pr_err("sysfs path crossed PATH_MAX(%d) size\n", PATH_MAX); goto out; } @@ -501,7 +501,7 @@ static void set_max_node_num(void) /* get the highest possible cpu number for a sparse allocation */ ret = snprintf(path, PATH_MAX, "%s/devices/system/node/possible", mnt); - if (ret == PATH_MAX) { + if (ret >= PATH_MAX) { pr_err("sysfs path crossed PATH_MAX(%d) size\n", PATH_MAX); goto out; } @@ -586,7 +586,7 @@ int cpu__setup_cpunode_map(void) return 0; n = snprintf(path, PATH_MAX, "%s/devices/system/node", mnt); - if (n == PATH_MAX) { + if (n >= PATH_MAX) { pr_err("sysfs path crossed PATH_MAX(%d) size\n", PATH_MAX); return -1; } @@ -601,7 +601,7 @@ int cpu__setup_cpunode_map(void) continue; n = snprintf(buf, PATH_MAX, "%s/%s", path, dent1->d_name); - if (n == PATH_MAX) { + if (n >= PATH_MAX) { pr_err("sysfs path crossed PATH_MAX(%d) size\n", PATH_MAX); continue; } -- 2.25.1