On Fri, Jan 08, 2016 at 11:30:47AM +0000, Matt Fleming wrote: > On Tue, 05 Jan, at 05:38:54PM, Môshe van der Sterre wrote: > > On 01/05/2016 04:46 PM, Matt Fleming wrote: > > >Shouldn't this be pr_debug() instead of pr_err()? > > > > It is an actual error for the image to be anything else. I did look at your > > commit "x86/efi-bgrt: Switch pr_err() to pr_debug() for invalid BGRT", and > > actually intentionally chose pr_err() instead of pr_debug() because of it. > > > > From that commit message: > > However, Josh points that out it still makes sense to test the > > validity of the upper 7 bits of the 'status' field, since > > they're marked as "reserved" in the spec and must be zero. If > > firmware violates this it really *is* an error. > > > > From the ACPI spec: > > If the value is 0, the Image Type is Bitmap. The format for a Bitmap is > > defined at the reference located in the ACPI Link Document under the heading > > "Types of Bitmaps". All other values not defined in the table are reserved > > for future use. > > and also: > > Implementations must present the image in a 24 bit bitmap with pixel > > format 0xRRGGBB, or a 32-bit bitmap with the pixel format 0xrrRRGGBB, where > > ‘rr’ is reserved. > > Following the link to MSDN, the header id is definitely also required to be > > "BM" for those types, > > That said, I'm not 100% sure if pr_err() is right for any of the errors in > > OK, I'll queue this up. Josh, does this look OK to you? Yes, checking the bitmap file header seems like a good additional cross-check. And since the spec says that the image must be a bitmap (given the one possible value for the format field), and since we can't reliably know *how much* data to read without reading the bitmap header, we should indeed error out if the data doesn't look like a bitmap. Reviewed-by: Josh Triplett <josh@xxxxxxxxxxxxxxxx> -- To unsubscribe from this list: send the line "unsubscribe linux-efi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
