From 4ba7978e98a3ff92cebfb0f31a02c309e3ffa1fe Mon Sep 17 00:00:00 2001 From: Li Zefan Date: Tue, 22 Sep 2009 13:52:20 +0800 Subject: [PATCH] tracing: Check the return value of trace_get_user() Return immediately if trace_get_user() returned failure. Signed-off-by: Li Zefan Cc: Frederic Weisbecker Cc: Jiri Olsa Cc: Steven Rostedt LKML-Reference: <4AB86614.7020803@cn.fujitsu.com> Signed-off-by: Ingo Molnar --- kernel/trace/ftrace.c | 9 ++++----- kernel/trace/trace_events.c | 7 +++---- 2 files changed, 7 insertions(+), 9 deletions(-) diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c index c71e91bf7372..a8fe4782ebad 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 */ diff --git a/kernel/trace/trace_events.c b/kernel/trace/trace_events.c index 6f03c8a1105e..d128f65778e6 100644 --- a/kernel/trace/trace_events.c +++ b/kernel/trace/trace_events.c @@ -232,10 +232,9 @@ ftrace_event_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) + if (!cnt) return 0; ret = tracing_update_buffers(); @@ -247,7 +246,7 @@ ftrace_event_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))) { int set = 1; if (*parser.buffer == '!') -- 2.20.1