[PATCH] HID: hidraw: enforce minors_lock locking via lockdep

From: Jiri Kosina
Date: Thu Nov 08 2018 - 16:38:47 EST


From: Jiri Kosina <jkosina@xxxxxxx>

lockdep is much more powerful enforcing the locking rules than code comments,
so let's switch to it.

Signed-off-by: Jiri Kosina <jkosina@xxxxxxx>
---
drivers/hid/hidraw.c | 6 ++++--
1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/drivers/hid/hidraw.c b/drivers/hid/hidraw.c
index 4a44e48e08b2..cf2af069204f 100644
--- a/drivers/hid/hidraw.c
+++ b/drivers/hid/hidraw.c
@@ -107,8 +107,6 @@ static ssize_t hidraw_read(struct file *file, char __user *buffer, size_t count,

/*
* The first byte of the report buffer is expected to be a report number.
- *
- * This function is to be called with the minors_lock mutex held.
*/
static ssize_t hidraw_send_report(struct file *file, const char __user *buffer, size_t count, unsigned char report_type)
{
@@ -117,6 +115,8 @@ static ssize_t hidraw_send_report(struct file *file, const char __user *buffer,
__u8 *buf;
int ret = 0;

+ lockdep_assert_held(&minors_lock);
+
if (!hidraw_table[minor] || !hidraw_table[minor]->exist) {
ret = -ENODEV;
goto out;
@@ -192,6 +192,8 @@ static ssize_t hidraw_get_report(struct file *file, char __user *buffer, size_t
int ret = 0, len;
unsigned char report_number;

+ lockdep_assert_held(&minors_lock);
+
if (!hidraw_table[minor] || !hidraw_table[minor]->exist) {
ret = -ENODEV;
goto out;
--
Jiri Kosina
SUSE Labs