Messages in this thread | | | Subject | Re: [PATCH v2] x86/boot: define CC_HAVE_ASM_GOTO | From | "H. Peter Anvin" <> | Date | Mon, 1 Oct 2018 10:38:33 -0700 |
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On 09/27/18 13:47, ndesaulniers@google.com wrote: > Early prototypes of Clang with asm goto support produce 6 instances of > the following warning: > > In file included from arch/x86/boot/compressed/misc.h:20: > In file included from ./include/linux/elf.h:5: > In file included from ./arch/x86/include/asm/elf.h:8: > In file included from ./include/linux/thread_info.h:38: > In file included from ./arch/x86/include/asm/thread_info.h:53: > ./arch/x86/include/asm/cpufeature.h:150:2: warning: "Compiler lacks > ASM_GOTO support. Add -D __BPF_TRACING__ to your compiler arguments" > [-W#warnings] > your compiler arguments" > ^ > > Since 6 files under arch/x86/boot/compressed/ include > arch/x86/boot/compressed/misc.h AND > arch/x86/boot/compressed/Makefile happens to redefine KBUILD_CFLAGS, > which set these variables in the top level MAKEFILE. >
The Right Thing[TM] would probably be to split the CFLAGS into those that are independent of x86_64 vs i386. After all, there is no fundamental reason we couldn't want to use asm goto in the setup or real-mode code in the future. In addition to BIOS entry code there is the EFI32 code.
-hpa
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