lkml.org 
[lkml]   [2021]   [Jun]   [9]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[RFC PATCH 2/5] kprobes: Use helper to parse boolean input from userspace
Date
The "enabled" file provides a debugfs interface to arm / disarm
kprobes in the kernel. In order to parse the buffer containing the
values written from userspace, the callback manually parses the user
input to convert it to a boolean value.

As taking a string value from userspace and converting it to boolean
is a common operation, a helper kstrtobool_from_user() is already
available in the kernel. Update the callback to use the common helper
to parse the write buffer from userspace.

Signed-off-by: Punit Agrawal <punitagrawal@gmail.com>
---
kernel/kprobes.c | 28 ++++++----------------------
1 file changed, 6 insertions(+), 22 deletions(-)

diff --git a/kernel/kprobes.c b/kernel/kprobes.c
index fdb1ea2e963b..1a11d3c411bf 100644
--- a/kernel/kprobes.c
+++ b/kernel/kprobes.c
@@ -2777,30 +2777,14 @@ static ssize_t read_enabled_file_bool(struct file *file,
static ssize_t write_enabled_file_bool(struct file *file,
const char __user *user_buf, size_t count, loff_t *ppos)
{
- char buf[32];
- size_t buf_size;
- int ret = 0;
-
- buf_size = min(count, (sizeof(buf)-1));
- if (copy_from_user(buf, user_buf, buf_size))
- return -EFAULT;
+ bool enable;
+ int ret;

- buf[buf_size] = '\0';
- switch (buf[0]) {
- case 'y':
- case 'Y':
- case '1':
- ret = arm_all_kprobes();
- break;
- case 'n':
- case 'N':
- case '0':
- ret = disarm_all_kprobes();
- break;
- default:
- return -EINVAL;
- }
+ ret = kstrtobool_from_user(user_buf, count, &enable);
+ if (ret)
+ return ret;

+ ret = enable ? arm_all_kprobes() : disarm_all_kprobes();
if (ret)
return ret;

--
2.30.2
\
 
 \ /
  Last update: 2021-06-09 12:53    [W:0.083 / U:1.868 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site