archives/linux
1
0
Fork 0
mirror of https://github.com/torvalds/linux.git synced 2026-03-08 03:44:45 +01:00
Code Issues Projects Releases Packages Wiki Activity Actions

LoongArch: BPF: Use move_addr() for BPF_PSEUDO_FUNC

Browse source 
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 64f50f6575 ("LoongArch, bpf: Use 4 instructions for
function address in JIT") for a similar fix.

Cc: stable@vger.kernel.org
Fixes: 69c087ba62 ("bpf: Add bpf_for_each_map_elem() helper")
Fixes: bb035ef0cc ("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_NZsFXqEk4Cj1tsBNA@mail.gmail.com/T/#u
Signed-off-by: Hengqi Chen <hengqi.chen@gmail.com>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
This commit is contained in:
Hengqi Chen 2025-03-30 16:31:09 +08:00 • committed by Huacai Chen
parent 7e2586991e
commit 52266f1015
1 changed files with 4 additions and 1 deletions
Download patch file Download diff file Expand all files Collapse all files

5
arch/loongarch/net/bpf_jit.c
View file

@ -932,7 +932,10 @@ static int build_insn(const struct bpf_insn *insn, struct jit_ctx *ctx, bool ext
{
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;
}