bpf: Fix JIT of is_mov_percpu_addr instruction.

The codegen for is_mov_percpu_addr instruction works for rax/r8 registers
only. Fix it to generate proper x86 byte code for other registers.

Fixes: 7bdbf74463 ("bpf: add special internal-only MOV instruction to resolve per-CPU addrs")
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20240417214406.15788-1-alexei.starovoitov@gmail.com
This commit is contained in:
Alexei Starovoitov 2024-04-17 14:44:06 -07:00 committed by Andrii Nakryiko
parent e739e01d8d
commit 462e5e2a59

View File

@ -1439,7 +1439,7 @@ static int do_jit(struct bpf_prog *bpf_prog, int *addrs, u8 *image, u8 *rw_image
#ifdef CONFIG_SMP
/* add <dst>, gs:[<off>] */
EMIT2(0x65, add_1mod(0x48, dst_reg));
EMIT3(0x03, add_1reg(0x04, dst_reg), 0x25);
EMIT3(0x03, add_2reg(0x04, 0, dst_reg), 0x25);
EMIT((u32)(unsigned long)&this_cpu_off, 4);
#endif
break;