2022-06-23 01:54:02

by sunliming

Subject: [PATCH RESEND] drm/msm/dpu: Fix variable dereferenced before check

Fixes the following smatch warning:

drivers/gpu/drm/msm/disp/dpu1/dpu_encoder_phys_wb.c:261
dpu_encoder_phys_wb_atomic_check() warn: variable dereferenced before check 'conn_state'

Signed-off-by: sunliming <[email protected]>
Reported-by: kernel test robot <[email protected]>
Reported-by: Dan Carpenter <[email protected]>
Reviewed-by: Abhinav Kumar <[email protected]>
---
drivers/gpu/drm/msm/disp/dpu1/dpu_encoder_phys_wb.c | 10 +++++-----
1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder_phys_wb.c b/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder_phys_wb.c
index 59da348ff339..0ec809ab06e7 100644
--- a/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder_phys_wb.c
+++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder_phys_wb.c
@@ -252,11 +252,6 @@ static int dpu_encoder_phys_wb_atomic_check(
DPU_DEBUG("[atomic_check:%d, \"%s\",%d,%d]\n",
phys_enc->wb_idx, mode->name, mode->hdisplay, mode->vdisplay);

- if (!conn_state->writeback_job || !conn_state->writeback_job->fb)
- return 0;
-
- fb = conn_state->writeback_job->fb;
-
if (!conn_state || !conn_state->connector) {
DPU_ERROR("invalid connector state\n");
return -EINVAL;
@@ -267,6 +262,11 @@ static int dpu_encoder_phys_wb_atomic_check(
return -EINVAL;
}

+ if (!conn_state->writeback_job || !conn_state->writeback_job->fb)
+ return 0;
+
+ fb = conn_state->writeback_job->fb;
+
DPU_DEBUG("[fb_id:%u][fb:%u,%u]\n", fb->base.id,
fb->width, fb->height);

--
2.25.1

2022-06-23 19:14:31

by Abhinav Kumar

Subject: Re: [PATCH RESEND] drm/msm/dpu: Fix variable dereferenced before check

On 6/22/2022 6:27 PM, sunliming wrote:
> Fixes the following smatch warning:
>
> drivers/gpu/drm/msm/disp/dpu1/dpu_encoder_phys_wb.c:261
> dpu_encoder_phys_wb_atomic_check() warn: variable dereferenced before check 'conn_state'
>
> Signed-off-by: sunliming <[email protected]>
> Reported-by: kernel test robot <[email protected]>
> Reported-by: Dan Carpenter <[email protected]>
> Reviewed-by: Abhinav Kumar <[email protected]>
Fixes: d7d0e73f7de3 ("drm/msm/dpu: introduce the dpu_encoder_phys_* for
writeback")
> ---
> drivers/gpu/drm/msm/disp/dpu1/dpu_encoder_phys_wb.c | 10 +++++-----
> 1 file changed, 5 insertions(+), 5 deletions(-)
>
> diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder_phys_wb.c b/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder_phys_wb.c
> index 59da348ff339..0ec809ab06e7 100644
> --- a/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder_phys_wb.c
> +++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder_phys_wb.c
> @@ -252,11 +252,6 @@ static int dpu_encoder_phys_wb_atomic_check(
> DPU_DEBUG("[atomic_check:%d, \"%s\",%d,%d]\n",
> phys_enc->wb_idx, mode->name, mode->hdisplay, mode->vdisplay);
>
> - if (!conn_state->writeback_job || !conn_state->writeback_job->fb)
> - return 0;
> -
> - fb = conn_state->writeback_job->fb;
> -
> if (!conn_state || !conn_state->connector) {
> DPU_ERROR("invalid connector state\n");
> return -EINVAL;
> @@ -267,6 +262,11 @@ static int dpu_encoder_phys_wb_atomic_check(
> return -EINVAL;
> }
>
> + if (!conn_state->writeback_job || !conn_state->writeback_job->fb)
> + return 0;
> +
> + fb = conn_state->writeback_job->fb;
> +
> DPU_DEBUG("[fb_id:%u][fb:%u,%u]\n", fb->base.id,
> fb->width, fb->height);
>