2023-07-20 12:56:19

by Harshit Mogalapalli

Subject: [PATCH next] drm/loongson: Fix error handling in lsdc_pixel_pll_setup()

There are two problems in lsdc_pixel_pll_setup()
1. If kzalloc() fails then call iounmap() to release the resources.
2. Both kzalloc and ioremap doesnot return error pointers on failure, so
using IS_ERR_OR_NULL() checks is a bit confusing and not very right,
fix this by changing those to NULL checks instead.

Fixes: f39db26c5428 ("drm: Add kms driver for loongson display controller")
Signed-off-by: Harshit Mogalapalli <[email protected]>
---
This is found with static analysis with smacth and only compile tested.
---
drivers/gpu/drm/loongson/lsdc_pixpll.c | 6 ++++--
1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/loongson/lsdc_pixpll.c b/drivers/gpu/drm/loongson/lsdc_pixpll.c
index 04c15b4697e2..2609a2256da4 100644
--- a/drivers/gpu/drm/loongson/lsdc_pixpll.c
+++ b/drivers/gpu/drm/loongson/lsdc_pixpll.c
@@ -120,12 +120,14 @@ static int lsdc_pixel_pll_setup(struct lsdc_pixpll * const this)
struct lsdc_pixpll_parms *pparms;

this->mmio = ioremap(this->reg_base, this->reg_size);
- if (IS_ERR_OR_NULL(this->mmio))
+ if (!this->mmio)
return -ENOMEM;

pparms = kzalloc(sizeof(*pparms), GFP_KERNEL);
- if (IS_ERR_OR_NULL(pparms))
+ if (!pparms) {
+ iounmap(this->mmio);
return -ENOMEM;
+ }

pparms->ref_clock = LSDC_PLL_REF_CLK_KHZ;

--
2.39.3

2023-08-10 15:14:40

by Sui Jingfeng

Subject: Re: [PATCH next] drm/loongson: Fix error handling in lsdc_pixel_pll_setup()

Hi,


On 2023/7/20 20:39, Harshit Mogalapalli wrote:
> There are two problems in lsdc_pixel_pll_setup()
> 1. If kzalloc() fails then call iounmap() to release the resources.
> 2. Both kzalloc and ioremap doesnot return error pointers on failure, so
> using IS_ERR_OR_NULL() checks is a bit confusing and not very right,
> fix this by changing those to NULL checks instead.
>
> Fixes: f39db26c5428 ("drm: Add kms driver for loongson display controller")
> Signed-off-by: Harshit Mogalapalli <[email protected]>


Reviewed-by: Sui Jingfeng <[email protected]>


> ---
> This is found with static analysis with smacth and only compile tested.
> ---
> drivers/gpu/drm/loongson/lsdc_pixpll.c | 6 ++++--
> 1 file changed, 4 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/gpu/drm/loongson/lsdc_pixpll.c b/drivers/gpu/drm/loongson/lsdc_pixpll.c
> index 04c15b4697e2..2609a2256da4 100644
> --- a/drivers/gpu/drm/loongson/lsdc_pixpll.c
> +++ b/drivers/gpu/drm/loongson/lsdc_pixpll.c
> @@ -120,12 +120,14 @@ static int lsdc_pixel_pll_setup(struct lsdc_pixpll * const this)
> struct lsdc_pixpll_parms *pparms;
>
> this->mmio = ioremap(this->reg_base, this->reg_size);
> - if (IS_ERR_OR_NULL(this->mmio))
> + if (!this->mmio)
> return -ENOMEM;
>
> pparms = kzalloc(sizeof(*pparms), GFP_KERNEL);
> - if (IS_ERR_OR_NULL(pparms))
> + if (!pparms) {
> + iounmap(this->mmio);
> return -ENOMEM;
> + }
>
> pparms->ref_clock = LSDC_PLL_REF_CLK_KHZ;
>