On Fri, Aug 11, 2017 at 11:26 AM, Ard Biesheuvel <ard.biesheu...@linaro.org> wrote: > On 11 August 2017 at 10:22, Catalin Marinas <catalin.mari...@arm.com> wrote: >> On Thu, Aug 10, 2017 at 01:13:22PM -0700, Laura Abbott wrote: >>> Fedora rawhide recently upgraded to binutils 2.29 and this seems >>> to produce new warnings: >>> >>> ./arch/arm64/include/asm/assembler.h: Assembler messages: >>> ./arch/arm64/include/asm/assembler.h:125: Warning: ignoring attempt to >>> redefine built-in register 'lr' >>> >>> This is >>> >>> /* >>> * Register aliases. >>> */ >>> lr .req x30 // link register >> >> Strange, does gas now think 'lr' is a general purpose register (aliased >> to x30)? It never was and IIRC the toolchain people many years ago >> refused to add it, hence the alias above in the kernel. I wonder if they >> added 'fp' as well... >> >> We could remove the alias and replace all 'lr' instances with 'x30' >> throughout the kernel (no too many) or we add some #ifdef around the >> above based on the binutils version. >> > > This is annoying. Replacing x30 with lr achieves the opposite of the > intent of the binutils change. And using #ifdefs is inaccurate, > because you can't really test the binutils version only the GCC > version, and those are not tightly coupled. > > Can you .unreq it?
adding the author of the change to cc https://sourceware.org/git/?p=binutils-gdb.git;a=commitdiff;h=62e20ed45e3da5f3ba695e4ee109317668180fe6 There probably was some reasoning behind the change and an intended method for using it. Arnd