lkml.org 
[lkml]   [2019]   [Aug]   [2]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH 1/2] perf: Fix failure to set cpumask when only one cpu
Date
From: He Zhe <zhe.he@windriver.com>

The buffer containing string used to set cpumask is overwritten by end of
string later in cpu_map__snprint_mask due to not enough memory space, when
there is only one cpu. And thus causes the following failure.

$ perf ftrace ls
failed to reset ftrace

This patch fixes the calculation of cpumask string size.

Signed-off-by: He Zhe <zhe.he@windriver.com>
---
tools/perf/builtin-ftrace.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tools/perf/builtin-ftrace.c b/tools/perf/builtin-ftrace.c
index 66d5a66..0193128 100644
--- a/tools/perf/builtin-ftrace.c
+++ b/tools/perf/builtin-ftrace.c
@@ -173,7 +173,7 @@ static int set_tracing_cpumask(struct cpu_map *cpumap)
int last_cpu;

last_cpu = cpu_map__cpu(cpumap, cpumap->nr - 1);
- mask_size = (last_cpu + 3) / 4 + 1;
+ mask_size = last_cpu / 4 + 2; /* one more byte for EOS */
mask_size += last_cpu / 32; /* ',' is needed for every 32th cpus */

cpumask = malloc(mask_size);
--
2.7.4
\
 
 \ /
  Last update: 2019-08-02 10:33    [W:0.085 / U:4.312 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site