[Intel-gfx] [PATCH 16/26] drm/i915: Fix bug in user proto-context creation that leaked contexts

[John Harrison]

On 10/4/2021 15:06, Matthew Brost wrote:
> Set number of engines before attempting to create contexts so the
> function free_engines can clean up properly. Also check return of
> alloc_engines for NULL.
>
> v2:
>   (Tvrtko)
>    - Send as stand alone patch
>   (John Harrison)
>    - Check for alloc_engines returning NULL
> v3:
>   (Checkpatch / Tvrtko)
>    - Remove braces around single line if statement
>
> Cc: Jason Ekstrand <jason at jlekstrand.net>
> Fixes: d4433c7600f7 ("drm/i915/gem: Use the proto-context to handle create parameters (v5)")
> Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin at intel.com>
> Signed-off-by: Matthew Brost <matthew.brost at intel.com>
> Cc: <stable at vger.kernel.org>
Reviewed-by: John Harrison <John.C.Harrison at Intel.com>

> ---
>   drivers/gpu/drm/i915/gem/i915_gem_context.c | 5 ++++-
>   1 file changed, 4 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/gpu/drm/i915/gem/i915_gem_context.c b/drivers/gpu/drm/i915/gem/i915_gem_context.c
> index 8208fd5b72c3..8c7ea6e56262 100644
> --- a/drivers/gpu/drm/i915/gem/i915_gem_context.c
> +++ b/drivers/gpu/drm/i915/gem/i915_gem_context.c
> @@ -898,6 +898,10 @@ static struct i915_gem_engines *user_engines(struct i915_gem_context *ctx,
>   	unsigned int n;
>   
>   	e = alloc_engines(num_engines);
> +	if (!e)
> +		return ERR_PTR(-ENOMEM);
> +	e->num_engines = num_engines;
> +
>   	for (n = 0; n < num_engines; n++) {
>   		struct intel_context *ce;
>   		int ret;
> @@ -931,7 +935,6 @@ static struct i915_gem_engines *user_engines(struct i915_gem_context *ctx,
>   			goto free_engines;
>   		}
>   	}
> -	e->num_engines = num_engines;
>   
>   	return e;
>