On Thu, 12 May, at 08:48:35AM, Ingo Molnar wrote: > > * Alex Thorlton <athorlton@xxxxxxx> wrote: > > > The efi_call assembly code has a slight error that prevents us from > > using arguments 7 and higher, which will be passed in on the stack. > > > > mov (%rsp), %rax > > mov 8(%rax), %rax > > ... > > mov %rax, 40(%rsp) > > > > This code goes and grabs the return address for the current stack frame, > > and puts it on the stack, next the 5th argument for the EFI runtime > > call. Considering the fact that having the return address in that > > position on the stack makes no sense, I'm guessing that the intent of > > this code was actually to grab an argument off the stack frame for this > > call and place it into the frame for the next one. > > > > The small change to that offset (i.e. 8(%rax) to 16(%rax)) ensures that > > we grab the 7th argument off the stack, and pass it as the 6th argument > > to the EFI runtime function that we're about to call. This change gets > > our EFI runtime calls that need to pass more than 6 arguments working > > again. > > I suppose the SGI/UV code is the only one using 7 arguments or more? Might make > sense to point that out in the changelog. Yeah, I included that info when I applied this patch. -- 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
