]> git.ipfire.org Git - thirdparty/kernel/stable.git/commit
LoongArch: BPF: Use move_addr() for BPF_PSEUDO_FUNC
authorHengqi Chen <hengqi.chen@gmail.com>
Sun, 30 Mar 2025 08:31:09 +0000 (16:31 +0800)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Thu, 10 Apr 2025 12:37:41 +0000 (14:37 +0200)
commit7cf8fe2b2bccef6a2be7fa8819cbbdffeabe53ad
treed7ba0c561236007d6f580f0e1b736f8d970b87f3
parent7df2696256a034405d3c5a71b3a4c54725de4404
LoongArch: BPF: Use move_addr() for BPF_PSEUDO_FUNC

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_NZsFXqEk4Cj1tsBNA@mail.gmail.com/T/#u
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