6.6-stable review patch. If anyone has any objections, please let me know.
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From: Hengqi Chen hengqi.chen@gmail.com
commit 52266f1015a8b5aabec7d127f83d105f702b388e upstream.
Vincent reported that running XDP synproxy program on LoongArch results in the following error:
JIT doesn't support bpf-to-bpf calls
With dmesg:
multi-func JIT bug 1391 != 1390
The root cause is that verifier will refill the imm with the correct addresses of bpf_calls for BPF_PSEUDO_FUNC instructions and then run the last pass of JIT. So we generate different JIT code for the same instruction in two passes (one for placeholder and the other for the real address). Let's use move_addr() instead.
See commit 64f50f6575721ef0 ("LoongArch, bpf: Use 4 instructions for function address in JIT") for a similar fix.
Cc: stable@vger.kernel.org Fixes: 69c087ba6225 ("bpf: Add bpf_for_each_map_elem() helper") Fixes: bb035ef0cc91 ("LoongArch: BPF: Support mixing bpf2bpf and tailcalls") Reported-by: Vincent Li vincent.mc.li@gmail.com Tested-by: Vincent Li vincent.mc.li@gmail.com Closes: https://lore.kernel.org/loongarch/CAK3+h2yfM9FTNiXvEQBkvtuoJrvzmN4c_NZsFXqEk... Signed-off-by: Hengqi Chen hengqi.chen@gmail.com Signed-off-by: Huacai Chen chenhuacai@loongson.cn Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- arch/loongarch/net/bpf_jit.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-)
--- a/arch/loongarch/net/bpf_jit.c +++ b/arch/loongarch/net/bpf_jit.c @@ -872,7 +872,10 @@ static int build_insn(const struct bpf_i { const u64 imm64 = (u64)(insn + 1)->imm << 32 | (u32)insn->imm;
- move_imm(ctx, dst, imm64, is32); + if (bpf_pseudo_func(insn)) + move_addr(ctx, dst, imm64); + else + move_imm(ctx, dst, imm64, is32); return 1; }