Quoting Ville Syrjälä (2020-01-23 13:27:07)
On Thu, Jan 23, 2020 at 12:59:34PM +0000, Chris Wilson wrote:
To multiply 2 u32 numbers to generate a u64 in C requires a bit of forewarning for the compiler.
Signed-off-by: Chris Wilson chris@chris-wilson.co.uk Cc: Ramalingam C ramalingam.c@intel.com Cc: Joonas Lahtinen joonas.lahtinen@linux.intel.com Cc: stable@vger.kernel.org
drivers/gpu/drm/i915/i915_gem.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-)
diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c index 0a20083321a3..ff79da5657f8 100644 --- a/drivers/gpu/drm/i915/i915_gem.c +++ b/drivers/gpu/drm/i915/i915_gem.c @@ -265,7 +265,10 @@ i915_gem_dumb_create(struct drm_file *file, DRM_FORMAT_MOD_LINEAR)) args->pitch = ALIGN(args->pitch, 4096);
args->size = args->pitch * args->height;
if (args->pitch < args->width)return -EINVAL;args->size = mul_u32_u32(args->pitch, args->height);I thought something would have checked these against the mode_config fb limits already. But can't see code like that anywhere. Maybe we should just do that in the core?
While it is in uapi/drm_mode.h, is there any restriction that the dumb buffer has to be used with a framebuffer? Not that I have a good use case, just wondering if we need to be so proscriptive.
We create something that is compatible but presume we will need later validation against HW. -Chris