2019-01-21 21:25:53

by Alexey Khoroshilov

Subject: [PATCH v2] usb: dwc3: exynos: Fix error handling of clk_prepare_enable

If clk_prepare_enable() fails in dwc3_exynos_probe() or in
dwc3_exynos_resume(), exynos->clks[0] is left undisabled
because of usage preincrement in while condition.

Found by Linux Driver Verification project (linuxtesting.org).

Signed-off-by: Alexey Khoroshilov <[email protected]>
Fixes: 9f2168367a0a ("usb: dwc3: exynos: Rework clock handling and prepare for new variants")
---
v2: Add fix for the second instance in dwc3_exynos_resume() per Marek Szyprowski note.

drivers/usb/dwc3/dwc3-exynos.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/usb/dwc3/dwc3-exynos.c b/drivers/usb/dwc3/dwc3-exynos.c
index cb7fcd7c0ad8..c1e9ea621f41 100644
--- a/drivers/usb/dwc3/dwc3-exynos.c
+++ b/drivers/usb/dwc3/dwc3-exynos.c
@@ -78,7 +78,7 @@ static int dwc3_exynos_probe(struct platform_device *pdev)
for (i = 0; i < exynos->num_clks; i++) {
ret = clk_prepare_enable(exynos->clks[i]);
if (ret) {
- while (--i > 0)
+ while (i-- > 0)
clk_disable_unprepare(exynos->clks[i]);
return ret;
}
@@ -223,7 +223,7 @@ static int dwc3_exynos_resume(struct device *dev)
for (i = 0; i < exynos->num_clks; i++) {
ret = clk_prepare_enable(exynos->clks[i]);
if (ret) {
- while (--i > 0)
+ while (i-- > 0)
clk_disable_unprepare(exynos->clks[i]);
return ret;
}
--
2.7.4

2019-01-22 08:23:50

by Marek Szyprowski

Subject: Re: [PATCH v2] usb: dwc3: exynos: Fix error handling of clk_prepare_enable

Hi Alexey,

On 2019-01-21 22:23, Alexey Khoroshilov wrote:
> If clk_prepare_enable() fails in dwc3_exynos_probe() or in
> dwc3_exynos_resume(), exynos->clks[0] is left undisabled
> because of usage preincrement in while condition.
>
> Found by Linux Driver Verification project (linuxtesting.org).
>
> Signed-off-by: Alexey Khoroshilov <[email protected]>
> Fixes: 9f2168367a0a ("usb: dwc3: exynos: Rework clock handling and prepare for new variants")
Acked-by: Marek Szyprowski <[email protected]>
> ---
> v2: Add fix for the second instance in dwc3_exynos_resume() per Marek Szyprowski note.
>
> drivers/usb/dwc3/dwc3-exynos.c | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/usb/dwc3/dwc3-exynos.c b/drivers/usb/dwc3/dwc3-exynos.c
> index cb7fcd7c0ad8..c1e9ea621f41 100644
> --- a/drivers/usb/dwc3/dwc3-exynos.c
> +++ b/drivers/usb/dwc3/dwc3-exynos.c
> @@ -78,7 +78,7 @@ static int dwc3_exynos_probe(struct platform_device *pdev)
> for (i = 0; i < exynos->num_clks; i++) {
> ret = clk_prepare_enable(exynos->clks[i]);
> if (ret) {
> - while (--i > 0)
> + while (i-- > 0)
> clk_disable_unprepare(exynos->clks[i]);
> return ret;
> }
> @@ -223,7 +223,7 @@ static int dwc3_exynos_resume(struct device *dev)
> for (i = 0; i < exynos->num_clks; i++) {
> ret = clk_prepare_enable(exynos->clks[i]);
> if (ret) {
> - while (--i > 0)
> + while (i-- > 0)
> clk_disable_unprepare(exynos->clks[i]);
> return ret;
> }

Best regards
--
Marek Szyprowski, PhD
Samsung R&D Institute Poland