From: Yonghong Song <yhs@fb.com>
Date: Tue, 18 Feb 2020 16:42:36 -0800
Subject: selftests/bpf: Change llvm flag -mcpu=probe to -mcpu=v3
Patch-mainline: v5.7-rc1
Git-commit: 83250f2b6940654a73a2cfab7ac112b804a5f648
References: bsc#1177028
The latest llvm supports cpu version v3, which is cpu version v1
plus some additional 64bit jmp insns and 32bit jmp insn support.
In selftests/bpf Makefile, the llvm flag -mcpu=probe did runtime
probe into the host system. Depending on compilation environments,
it is possible that runtime probe may fail, e.g., due to
memlock issue. This will cause generated code with cpu version v1.
This may cause confusion as the same compiler and the same C code
generates different byte codes in different environment.
Let us change the llvm flag -mcpu=probe to -mcpu=v3 so the
generated code will be the same regardless of the compilation
environment.
Signed-off-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Link: https://lore.kernel.org/bpf/20200219004236.2291125-1-yhs@fb.com
Acked-by: Gary Lin <glin@suse.com>
---
tools/testing/selftests/bpf/Makefile | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
--- a/tools/testing/selftests/bpf/Makefile
+++ b/tools/testing/selftests/bpf/Makefile
@@ -208,7 +208,7 @@ define CLANG_BPF_BUILD_RULE
$(call msg,CLNG-LLC,$(TRUNNER_BINARY),$2)
($(CLANG) $3 -O2 -target bpf -emit-llvm \
-c $1 -o - || echo "BPF obj compilation failed") | \
- $(LLC) -mattr=dwarfris -march=bpf -mcpu=probe $4 -filetype=obj -o $2
+ $(LLC) -mattr=dwarfris -march=bpf -mcpu=v3 $4 -filetype=obj -o $2
endef
# Similar to CLANG_BPF_BUILD_RULE, but with disabled alu32
define CLANG_NOALU32_BPF_BUILD_RULE
@@ -222,7 +222,7 @@ define CLANG_NATIVE_BPF_BUILD_RULE
$(call msg,CLNG-BPF,$(TRUNNER_BINARY),$2)
($(CLANG) $3 -O2 -emit-llvm \
-c $1 -o - || echo "BPF obj compilation failed") | \
- $(LLC) -march=bpf -mcpu=probe $4 -filetype=obj -o $2
+ $(LLC) -march=bpf -mcpu=v3 $4 -filetype=obj -o $2
endef
# Build BPF object using GCC
define GCC_BPF_BUILD_RULE