2020-05-22 05:47:27

by Dinghao Liu

Subject: [PATCH] [v3] usb: musb: Fix runtime PM imbalance on error

When copy_from_user() returns an error code, there
is a runtime PM usage counter imbalance.

Fix this by moving copy_from_user() to the beginning
of this function.

Signed-off-by: Dinghao Liu <[email protected]>
---

Changelog:

v2: - Move copy_from_user() to the beginning rather
than adding pm_runtime_put_autosuspend().

v3: - Add missing changelog information.
---
drivers/usb/musb/musb_debugfs.c | 10 +++++-----
1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/drivers/usb/musb/musb_debugfs.c b/drivers/usb/musb/musb_debugfs.c
index 7b6281ab62ed..30a89aa8a3e7 100644
--- a/drivers/usb/musb/musb_debugfs.c
+++ b/drivers/usb/musb/musb_debugfs.c
@@ -168,6 +168,11 @@ static ssize_t musb_test_mode_write(struct file *file,
u8 test;
char buf[24];

+ memset(buf, 0x00, sizeof(buf));
+
+ if (copy_from_user(buf, ubuf, min_t(size_t, sizeof(buf) - 1, count)))
+ return -EFAULT;
+
pm_runtime_get_sync(musb->controller);
test = musb_readb(musb->mregs, MUSB_TESTMODE);
if (test) {
@@ -176,11 +181,6 @@ static ssize_t musb_test_mode_write(struct file *file,
goto ret;
}

- memset(buf, 0x00, sizeof(buf));
-
- if (copy_from_user(buf, ubuf, min_t(size_t, sizeof(buf) - 1, count)))
- return -EFAULT;
-
if (strstarts(buf, "force host full-speed"))
test = MUSB_TEST_FORCE_HOST | MUSB_TEST_FORCE_FS;

--
2.17.1

2020-05-22 15:41:19

by Bin Liu

Subject: Re: [PATCH] [v3] usb: musb: Fix runtime PM imbalance on error

On Fri, May 22, 2020 at 01:42:35PM +0800, Dinghao Liu wrote:
> When copy_from_user() returns an error code, there
> is a runtime PM usage counter imbalance.
>
> Fix this by moving copy_from_user() to the beginning
> of this function.
>
> Signed-off-by: Dinghao Liu <[email protected]>
> ---
>
> Changelog:
>
> v2: - Move copy_from_user() to the beginning rather
> than adding pm_runtime_put_autosuspend().
>
> v3: - Add missing changelog information.

Queued for v5.8. Thanks.
-Bin.