From: Nathan Chancellor nathan@kernel.org
mainline inclusion from mainline-v6.0-rc1 commit 33f32e5072b6cc84d1b130a3ad485849bcec907a category: feature bugzilla: https://gitee.com/openeuler/kernel/issues/I9FGRE
Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?i...
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When building with clang + CONFIG_CFI_CLANG=y, the following error occurs at link time:
ld.lld: error: undefined symbol: dummy_tramp
dummy_tramp is declared globally in C but its definition in inline assembly does not use .global, which prevents clang from properly resolving the references to it when creating the CFI jump tables.
Mark dummy_tramp as global so that the reference can be properly resolved.
Fixes: b2ad54e1533e ("bpf, arm64: Implement bpf_arch_text_poke() for arm64") Suggested-by: Sami Tolvanen samitolvanen@google.com Signed-off-by: Nathan Chancellor nathan@kernel.org Signed-off-by: Daniel Borkmann daniel@iogearbox.net Reviewed-by: Stanislav Fomichev sdf@google.com Link: https://github.com/ClangBuiltLinux/linux/issues/1661 Link: https://lore.kernel.org/bpf/20220713173503.3889486-1-nathan@kernel.org Signed-off-by: Pu Lehui pulehui@huawei.com --- arch/arm64/net/bpf_jit_comp.c | 1 + 1 file changed, 1 insertion(+)
diff --git a/arch/arm64/net/bpf_jit_comp.c b/arch/arm64/net/bpf_jit_comp.c index 6e4205c2fced..43c5a657f521 100644 --- a/arch/arm64/net/bpf_jit_comp.c +++ b/arch/arm64/net/bpf_jit_comp.c @@ -420,6 +420,7 @@ void dummy_tramp(void);
asm ( " .pushsection .text, "ax", @progbits\n" +" .global dummy_tramp\n" " .type dummy_tramp, %function\n" "dummy_tramp:" #if IS_ENABLED(CONFIG_ARM64_BTI_KERNEL)