Re: [PATCH] drm/atomic: fix memory leak when fetching format name

[Eric Engestrom]

On Friday, 2016-11-11 16:26:22 +, Colin King wrote:
> From: Colin Ian King 
> 
> drm_get_format_name allocates memory that is not currently free'd
> when printing the state. Fix this by kfree'ing the memory after
> use.

You are correct, but there are more cases of this, and another fix
has been chosen. See this patch [1] for the fix and the rest of that
thread [2] for the discussion.

I'll send v4 (rebase and a missed `const`) as soon as I have the time,
but the usage will remain the same as in v3.

Cheers,
  Eric

[1] https://lists.freedesktop.org/archives/dri-devel/2016-November/123250.html
[2] 
https://lists.freedesktop.org/archives/dri-devel/2016-November/thread.html#122845

> 
> Signed-off-by: Colin Ian King 
> ---
>  drivers/gpu/drm/drm_atomic.c | 5 +++--
>  1 file changed, 3 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/gpu/drm/drm_atomic.c b/drivers/gpu/drm/drm_atomic.c
> index f5ea7db..1d5e86a 100644
> --- a/drivers/gpu/drm/drm_atomic.c
> +++ b/drivers/gpu/drm/drm_atomic.c
> @@ -917,9 +917,10 @@ static void drm_atomic_plane_print_state(struct 
> drm_printer *p,
>   if (state->fb) {
>   struct drm_framebuffer *fb = state->fb;
>   int i, n = drm_format_num_planes(fb->pixel_format);
> + char *format_name = drm_get_format_name(fb->pixel_format);
>  
> - drm_printf(p, "\t\tformat=%s\n",
> - drm_get_format_name(fb->pixel_format));
> + drm_printf(p, "\t\tformat=%s\n", format_name);
> + kfree(format_name);
>   drm_printf(p, "\t\tsize=%dx%d\n", fb->width, fb->height);
>   drm_printf(p, "\t\tlayers:\n");
>   for (i = 0; i < n; i++) {
> -- 
> 2.10.2
> 

[PATCH] drm/atomic: fix memory leak when fetching format name

[Colin King]

From: Colin Ian King 

drm_get_format_name allocates memory that is not currently free'd
when printing the state. Fix this by kfree'ing the memory after
use.

Signed-off-by: Colin Ian King 
---
 drivers/gpu/drm/drm_atomic.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/drm_atomic.c b/drivers/gpu/drm/drm_atomic.c
index f5ea7db..1d5e86a 100644
--- a/drivers/gpu/drm/drm_atomic.c
+++ b/drivers/gpu/drm/drm_atomic.c
@@ -917,9 +917,10 @@ static void drm_atomic_plane_print_state(struct 
drm_printer *p,
if (state->fb) {
struct drm_framebuffer *fb = state->fb;
int i, n = drm_format_num_planes(fb->pixel_format);
+   char *format_name = drm_get_format_name(fb->pixel_format);
 
-   drm_printf(p, "\t\tformat=%s\n",
-   drm_get_format_name(fb->pixel_format));
+   drm_printf(p, "\t\tformat=%s\n", format_name);
+   kfree(format_name);
drm_printf(p, "\t\tsize=%dx%d\n", fb->width, fb->height);
drm_printf(p, "\t\tlayers:\n");
for (i = 0; i < n; i++) {
-- 
2.10.2