On Fri, Jun 07, 2019 at 11:26:11AM -0400, Qian Cai wrote: > On Fri, 2019-06-07 at 16:25 +0100, Will Deacon wrote: > > On Fri, Jun 07, 2019 at 11:22:45AM -0400, Qian Cai wrote: > > > The linux-next commit "arm64: Silence gcc warnings about arch ABI drift" > > > [1] > > > breaks clang build where it screams that unknown option "-Wno-psabi" and > > > generates errors below, > > > > So that can be easily fixed with cc-option... > > > > > [1] > > > https://lore.kernel.org/linux-arm-kernel/1559817223-32585-1-git-send-ema > > > il-D > > > [email protected]/ > > > > > > ./drivers/firmware/efi/libstub/arm-stub.stub.o: In function > > > `install_memreserve_table': > > > ./linux/drivers/firmware/efi/libstub/arm-stub.c:73: undefined reference to > > > `__efistub___stack_chk_guard' > > > ./linux/drivers/firmware/efi/libstub/arm-stub.c:73: undefined reference to > > > `__efistub___stack_chk_guard' > > > ./linux/drivers/firmware/efi/libstub/arm-stub.c:93: undefined reference to > > > `__efistub___stack_chk_guard' > > > ./linux/drivers/firmware/efi/libstub/arm-stub.c:93: undefined reference to > > > `__efistub___stack_chk_guard' > > > ./linux/drivers/firmware/efi/libstub/arm-stub.c:94: undefined reference to > > > `__efistub___stack_chk_fail > > > > ... but this looks unrelated. Are you saying you don't see these errors if > > you revert Dave's patch? > > Yes.
I suspect the reason for this is -Wunknown-warning-option causes cc-option to fail. I see some disabled warnings like -Waddress-of-packed-member and -Wunused-const-variable when -Wno-psabi is unconditionally added. I'll do some further triage but I think the obvious fix as Will suggested is to use cc-disable-warning. I'll send a patch. Cheers, Nathan
