From: Xu Kuohai xukuohai@huawei.com
mainline inclusion from mainline-v6.0-rc1 commit 339ed900b3079b6ea21df55f368b1ccba17cd5e6 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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dummy_tramp() uses "lr" to refer to the x30 register, but some assembler does not recognize "lr" and reports a build failure:
/tmp/cc52xO0c.s: Assembler messages: /tmp/cc52xO0c.s:8: Error: operand 1 should be an integer register -- `mov lr,x9' /tmp/cc52xO0c.s:7: Error: undefined symbol lr used as an immediate value make[2]: *** [scripts/Makefile.build:250: arch/arm64/net/bpf_jit_comp.o] Error 1 make[1]: *** [scripts/Makefile.build:525: arch/arm64/net] Error 2
So replace "lr" with "x30" to fix it.
Fixes: b2ad54e1533e ("bpf, arm64: Implement bpf_arch_text_poke() for arm64") Reported-by: Jon Hunter jonathanh@nvidia.com Signed-off-by: Xu Kuohai xukuohai@huawei.com Signed-off-by: Daniel Borkmann daniel@iogearbox.net Tested-by: Jon Hunter jonathanh@nvidia.com Reviewed-by: Jean-Philippe Brucker jean-philippe@linaro.org Link: https://lore.kernel.org/bpf/20220721121319.2999259-1-xukuohai@huaweicloud.co... Signed-off-by: Pu Lehui pulehui@huawei.com --- arch/arm64/net/bpf_jit_comp.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/arch/arm64/net/bpf_jit_comp.c b/arch/arm64/net/bpf_jit_comp.c index 43c5a657f521..a5241345ef42 100644 --- a/arch/arm64/net/bpf_jit_comp.c +++ b/arch/arm64/net/bpf_jit_comp.c @@ -426,8 +426,8 @@ asm ( #if IS_ENABLED(CONFIG_ARM64_BTI_KERNEL) " bti j\n" /* dummy_tramp is called via "br x10" */ #endif -" mov x10, lr\n" -" mov lr, x9\n" +" mov x10, x30\n" +" mov x30, x9\n" " ret x10\n" " .size dummy_tramp, .-dummy_tramp\n" " .popsection\n"