From: Christophe JAILLET <christophe.jaillet@xxxxxxxxxx>
[ 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@xxxxxxxxxx>
Suggested-by: David Laight <David.Laight@xxxxxxxxxx>
Cc: Alexander Shishkin <alexander.shishkin@xxxxxxxxxxxxxxx>
Cc: Don Zickus <dzickus@xxxxxxxxxx>
Cc: He Zhe <zhe.he@xxxxxxxxxxxxx>
Cc: Jan Stancek <jstancek@xxxxxxxxxx>
Cc: Jiri Olsa <jolsa@xxxxxxxxxx>
Cc: Kan Liang <kan.liang@xxxxxxxxxxxxxxx>
Cc: Mark Rutland <mark.rutland@xxxxxxx>
Cc: Namhyung Kim <namhyung@xxxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: kernel-janitors@xxxxxxxxxxxxxxx
Link: http://lore.kernel.org/lkml/20200324070319.10901-1-christophe.jaillet@xxxxxxxxxx
Signed-off-by: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
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 f93846edc1e0d..827d844f4efb1 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
