diff options
| author | Alexei Starovoitov <ast@kernel.org> | 2018-05-13 21:32:22 +0200 |
|---|---|---|
| committer | Thomas Gleixner <tglx@linutronix.de> | 2018-05-13 21:49:14 +0200 |
| commit | b1ae32dbab50ed19cfc16d225b0fb0114fb13025 (patch) | |
| tree | 57c5c39ada4cb8f287392d5e0630edea43667ccd | |
| parent | uprobes/x86: Prohibit probing on MOV SS instruction (diff) | |
| download | linux-b1ae32dbab50ed19cfc16d225b0fb0114fb13025.tar.xz linux-b1ae32dbab50ed19cfc16d225b0fb0114fb13025.zip | |
x86/cpufeature: Guard asm_volatile_goto usage for BPF compilation
Workaround for the sake of BPF compilation which utilizes kernel
headers, but clang does not support ASM GOTO and fails the build.
Fixes: d0266046ad54 ("x86: Remove FAST_FEATURE_TESTS")
Suggested-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: daniel@iogearbox.net
Cc: peterz@infradead.org
Cc: netdev@vger.kernel.org
Cc: bp@alien8.de
Cc: yhs@fb.com
Cc: kernel-team@fb.com
Cc: torvalds@linux-foundation.org
Cc: davem@davemloft.net
Link: https://lkml.kernel.org/r/20180513193222.1997938-1-ast@kernel.org
| -rw-r--r-- | arch/x86/include/asm/cpufeature.h | 15 | ||||
| -rw-r--r-- | samples/bpf/Makefile | 2 |
2 files changed, 16 insertions, 1 deletions
diff --git a/arch/x86/include/asm/cpufeature.h b/arch/x86/include/asm/cpufeature.h index b27da9602a6d..aced6c9290d6 100644 --- a/arch/x86/include/asm/cpufeature.h +++ b/arch/x86/include/asm/cpufeature.h @@ -140,6 +140,20 @@ extern void clear_cpu_cap(struct cpuinfo_x86 *c, unsigned int bit); #define setup_force_cpu_bug(bit) setup_force_cpu_cap(bit) +#if defined(__clang__) && !defined(CC_HAVE_ASM_GOTO) + +/* + * Workaround for the sake of BPF compilation which utilizes kernel + * headers, but clang does not support ASM GOTO and fails the build. + */ +#ifndef __BPF_TRACING__ +#warning "Compiler lacks ASM_GOTO support. Add -D __BPF_TRACING__ to your compiler arguments" +#endif + +#define static_cpu_has(bit) boot_cpu_has(bit) + +#else + /* * Static testing of CPU features. Used the same as boot_cpu_has(). * These will statically patch the target code for additional @@ -195,6 +209,7 @@ t_no: boot_cpu_has(bit) : \ _static_cpu_has(bit) \ ) +#endif #define cpu_has_bug(c, bit) cpu_has(c, (bit)) #define set_cpu_bug(c, bit) set_cpu_cap(c, (bit)) diff --git a/samples/bpf/Makefile b/samples/bpf/Makefile index 4d6a6edd4bf6..092947676143 100644 --- a/samples/bpf/Makefile +++ b/samples/bpf/Makefile @@ -255,7 +255,7 @@ $(obj)/tracex5_kern.o: $(obj)/syscall_nrs.h $(obj)/%.o: $(src)/%.c $(CLANG) $(NOSTDINC_FLAGS) $(LINUXINCLUDE) $(EXTRA_CFLAGS) -I$(obj) \ -I$(srctree)/tools/testing/selftests/bpf/ \ - -D__KERNEL__ -Wno-unused-value -Wno-pointer-sign \ + -D__KERNEL__ -D__BPF_TRACING__ -Wno-unused-value -Wno-pointer-sign \ -D__TARGET_ARCH_$(ARCH) -Wno-compare-distinct-pointer-types \ -Wno-gnu-variable-sized-type-not-at-end \ -Wno-address-of-packed-member -Wno-tautological-compare \ |