[tip:perf/core] ksym_tracer: Fix validation of access type

tip-bot for Li Zefan
2009-11-21T13:34:54Z

Commit-ID: f088e5471297cc78d7465e1fd997cb1a91a48019
Gitweb: http://git.kernel.org/tip/f088e5471297cc78d7465e1fd997cb1a91a48019
Author: Li Zefan <lizf@cn.fujitsu.com>
AuthorDate: Tue, 7 Jul 2009 13:53:18 +0800
Committer: Ingo Molnar <mingo@elte.hu>
CommitDate: Fri, 10 Jul 2009 11:59:41 +0200

ksym_tracer: Fix validation of access type

# echo 'pid_max:rw-' > ksym_trace_filter
# cat ksym_trace_filter
pid_max:rw-
# echo 'pid_max:ww-' > ksym_trace_filter
(should return -EINVAL)
# cat ksym_trace_filter
(but it ended up removing filter entry)

Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
Acked-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: "K.Prasad" <prasad@linux.vnet.ibm.com>
Cc: Alan Stern <stern@rowland.harvard.edu>
Cc: Steven Rostedt <rostedt@goodmis.org>
LKML-Reference: <4A52E2CE.6080409@cn.fujitsu.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
---
kernel/trace/trace_ksym.c | 32 ++++++++++++++------------------
1 files changed, 14 insertions(+), 18 deletions(-)

diff --git a/kernel/trace/trace_ksym.c b/kernel/trace/trace_ksym.c
index b6710d3..9556009 100644
--- a/kernel/trace/trace_ksym.c
+++ b/kernel/trace/trace_ksym.c
@@ -114,24 +114,22 @@ void ksym_hbp_handler(struct hw_breakpoint *hbp, struct pt_regs *regs)
* --x : Set Execution Break points (Not available yet)
*
*/
-static int ksym_trace_get_access_type(char *access_str)
+static int ksym_trace_get_access_type(char *str)
{
- int pos, access = 0;
+ int access = 0;

- for (pos = 0; pos < KSYM_TRACER_OP_LEN; pos++) {
- switch (access_str[pos]) {
- case 'r':
- access += (pos == 0) ? 4 : -1;
- break;
- case 'w':
- access += (pos == 1) ? 2 : -1;
- break;
- case '-':
- break;
- default:
- return -EINVAL;
- }
- }
+ if (str[0] == 'r')
+ access += 4;
+ else if (str[0] != '-')
+ return -EINVAL;
+
+ if (str[1] == 'w')
+ access += 2;
+ else if (str[1] != '-')
+ return -EINVAL;
+
+ if (str[2] != '-')
+ return -EINVAL;

switch (access) {
case 6:
@@ -140,8 +138,6 @@ static int ksym_trace_get_access_type(char *access_str)
case 2:
access = HW_BREAKPOINT_WRITE;
break;
- case 0:
- access = 0;
}

return access;