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authorLi Zefan <lizf@cn.fujitsu.com>2009-09-22 13:52:20 +0800
committerIngo Molnar <mingo@elte.hu>2009-09-22 10:28:55 +0200
commit4ba7978e98a3ff92cebfb0f31a02c309e3ffa1fe (patch)
tree47d8b3b0927a7413fabcc634023b45350f344d89 /kernel/trace/ftrace.c
parent3c235a337e205da0f614e456be72881483dcde6e (diff)
tracing: Check the return value of trace_get_user()
Return immediately if trace_get_user() returned failure. Signed-off-by: Li Zefan <lizf@cn.fujitsu.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Steven Rostedt <rostedt@goodmis.org> LKML-Reference: <4AB86614.7020803@cn.fujitsu.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'kernel/trace/ftrace.c')
-rw-r--r--kernel/trace/ftrace.c9
1 files changed, 4 insertions, 5 deletions
diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
index c71e91bf737..a8fe4782eba 100644
--- a/kernel/trace/ftrace.c
+++ b/kernel/trace/ftrace.c
@@ -2202,7 +2202,7 @@ ftrace_regex_write(struct file *file, const char __user *ubuf,
struct trace_parser *parser;
ssize_t ret, read;
- if (!cnt || cnt < 0)
+ if (!cnt)
return 0;
mutex_lock(&ftrace_regex_lock);
@@ -2216,7 +2216,7 @@ ftrace_regex_write(struct file *file, const char __user *ubuf,
parser = &iter->parser;
read = trace_get_user(parser, ubuf, cnt, ppos);
- if (trace_parser_loaded(parser) &&
+ if (read >= 0 && trace_parser_loaded(parser) &&
!trace_parser_cont(parser)) {
ret = ftrace_process_regex(parser->buffer,
parser->idx, enable);
@@ -2552,8 +2552,7 @@ ftrace_graph_write(struct file *file, const char __user *ubuf,
size_t cnt, loff_t *ppos)
{
struct trace_parser parser;
- size_t read = 0;
- ssize_t ret;
+ ssize_t read, ret;
if (!cnt || cnt < 0)
return 0;
@@ -2572,7 +2571,7 @@ ftrace_graph_write(struct file *file, const char __user *ubuf,
read = trace_get_user(&parser, ubuf, cnt, ppos);
- if (trace_parser_loaded((&parser))) {
+ if (read >= 0 && trace_parser_loaded((&parser))) {
parser.buffer[parser.idx] = 0;
/* we allow only one expression at a time */