From 79f60d5bd0dd264b52bcfd2e604643edff13c776 Mon Sep 17 00:00:00 2001 From: Christophe JAILLET Date: Tue, 24 Mar 2020 08:03:19 +0100 Subject: perf cpumap: Fix snprintf overflow check [ 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 Suggested-by: David Laight Cc: Alexander Shishkin Cc: Don Zickus Cc: He Zhe Cc: Jan Stancek Cc: Jiri Olsa Cc: Kan Liang Cc: Mark Rutland Cc: Namhyung Kim Cc: Peter Zijlstra Cc: kernel-janitors@vger.kernel.org Link: http://lore.kernel.org/lkml/20200324070319.10901-1-christophe.jaillet@wanadoo.fr Signed-off-by: Arnaldo Carvalho de Melo Signed-off-by: Sasha Levin --- tools/perf/util/cpumap.c | 10 +++++----- 1 file changed, 5 insertions(+), 5 deletions(-) (limited to 'tools') diff --git a/tools/perf/util/cpumap.c b/tools/perf/util/cpumap.c index a22c1114e880..324ec0456c83 100644 --- a/tools/perf/util/cpumap.c +++ b/tools/perf/util/cpumap.c @@ -299,7 +299,7 @@ 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; } @@ -310,7 +310,7 @@ 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; } @@ -338,7 +338,7 @@ 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; } @@ -423,7 +423,7 @@ 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; } @@ -438,7 +438,7 @@ 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; } -- cgit v1.2.3