[PATCH libdrm 2/2] xf86drmMode: smoke-test the atomic API

[Ville Syrjälä]

On Mon, Sep 07, 2015 at 10:53:06AM +0100, Emil Velikov wrote:
> As going through the modetest patches for atomic support I've noticed
> that if we pass NULL for the drmModeAtomicReqPtr argument we'll crash.
> 
> So let's handle things appropriately if the user forgot to check the
> return value of drmModeAtomicAlloc and drmModeAtomicDuplicate or made a
> typo somewhere along the way.

I'm not sure hand-holding the user to such an extent is actually useful.
OTOH I guess one NULL check per function call isn't all that expensive
either.

> 
> Cc: Ville Syrjälä <ville.syrjala at linux.intel.com>
> Cc: Rob Clark <robclark at freedesktop.org>
> Cc: Daniel Stone <daniels at collabora.com>
> Signed-off-by: Emil Velikov <emil.l.velikov at gmail.com>
> ---
>  xf86drmMode.c | 17 ++++++++++++++++-
>  1 file changed, 16 insertions(+), 1 deletion(-)
> 
> diff --git a/xf86drmMode.c b/xf86drmMode.c
> index 23800dd..ab6b519 100644
> --- a/xf86drmMode.c
> +++ b/xf86drmMode.c
> @@ -1189,6 +1189,9 @@ drmModeAtomicReqPtr drmModeAtomicDuplicate(drmModeAtomicReqPtr old)
>  {
>  	drmModeAtomicReqPtr new;
>  
> +	if (!old)
> +		return NULL;
> +
>  	new = drmMalloc(sizeof *new);
>  	if (!new)
>  		return NULL;
> @@ -1213,6 +1216,9 @@ drmModeAtomicReqPtr drmModeAtomicDuplicate(drmModeAtomicReqPtr old)
>  
>  int drmModeAtomicMerge(drmModeAtomicReqPtr base, drmModeAtomicReqPtr augment)
>  {
> +	if (!base)
> +		return -EINVAL;
> +
>  	if (!augment || augment->cursor == 0)
>  		return 0;
>  
> @@ -1239,12 +1245,15 @@ int drmModeAtomicMerge(drmModeAtomicReqPtr base, drmModeAtomicReqPtr augment)
>  
>  int drmModeAtomicGetCursor(drmModeAtomicReqPtr req)
>  {
> +	if (!req)
> +		return -EINVAL;
>  	return req->cursor;
>  }
>  
>  void drmModeAtomicSetCursor(drmModeAtomicReqPtr req, int cursor)
>  {
> -	req->cursor = cursor;
> +	if (req)
> +		req->cursor = cursor;
>  }
>  
>  int drmModeAtomicAddProperty(drmModeAtomicReqPtr req,
> @@ -1252,6 +1261,9 @@ int drmModeAtomicAddProperty(drmModeAtomicReqPtr req,
>  			     uint32_t property_id,
>  			     uint64_t value)
>  {
> +	if (!req)
> +		return -EINVAL;
> +
>  	if (req->cursor >= req->size_items) {
>  		drmModeAtomicReqItemPtr new;
>  
> @@ -1309,6 +1321,9 @@ int drmModeAtomicCommit(int fd, drmModeAtomicReqPtr req, uint32_t flags,
>  	int obj_idx = -1;
>  	int ret = -1;
>  
> +	if (!req)
> +		return -EINVAL;
> +
>  	if (req->cursor == 0)
>  		return 0;
>  
> -- 
> 2.5.0

-- 
Ville Syrjälä
Intel OTC