s390/bpf: Implement BPF_MOV | BPF_X with sign-extension

Implement the cpuv4 register-to-register move with sign extension. It
is distinguished from the normal moves by non-zero values in
insn->off, which determine the source size. s390x has instructions to
deal with all of them: lbr, lhr, lgbr, lghr and lgfr.

Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
Link: https://lore.kernel.org/r/20230919101336.2223655-5-iii@linux.ibm.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
This commit is contained in:
Ilya Leoshkevich 2023-09-19 12:09:06 +02:00 committed by Alexei Starovoitov
parent 9873ce2e9c
commit 3de55893f6

View File

@ -795,15 +795,47 @@ static noinline int bpf_jit_insn(struct bpf_jit *jit, struct bpf_prog *fp,
/*
* BPF_MOV
*/
case BPF_ALU | BPF_MOV | BPF_X: /* dst = (u32) src */
/* llgfr %dst,%src */
EMIT4(0xb9160000, dst_reg, src_reg);
if (insn_is_zext(&insn[1]))
insn_count = 2;
case BPF_ALU | BPF_MOV | BPF_X:
switch (insn->off) {
case 0: /* DST = (u32) SRC */
/* llgfr %dst,%src */
EMIT4(0xb9160000, dst_reg, src_reg);
if (insn_is_zext(&insn[1]))
insn_count = 2;
break;
case 8: /* DST = (u32)(s8) SRC */
/* lbr %dst,%src */
EMIT4(0xb9260000, dst_reg, src_reg);
/* llgfr %dst,%dst */
EMIT4(0xb9160000, dst_reg, dst_reg);
break;
case 16: /* DST = (u32)(s16) SRC */
/* lhr %dst,%src */
EMIT4(0xb9270000, dst_reg, src_reg);
/* llgfr %dst,%dst */
EMIT4(0xb9160000, dst_reg, dst_reg);
break;
}
break;
case BPF_ALU64 | BPF_MOV | BPF_X: /* dst = src */
/* lgr %dst,%src */
EMIT4(0xb9040000, dst_reg, src_reg);
case BPF_ALU64 | BPF_MOV | BPF_X:
switch (insn->off) {
case 0: /* DST = SRC */
/* lgr %dst,%src */
EMIT4(0xb9040000, dst_reg, src_reg);
break;
case 8: /* DST = (s8) SRC */
/* lgbr %dst,%src */
EMIT4(0xb9060000, dst_reg, src_reg);
break;
case 16: /* DST = (s16) SRC */
/* lghr %dst,%src */
EMIT4(0xb9070000, dst_reg, src_reg);
break;
case 32: /* DST = (s32) SRC */
/* lgfr %dst,%src */
EMIT4(0xb9140000, dst_reg, src_reg);
break;
}
break;
case BPF_ALU | BPF_MOV | BPF_K: /* dst = (u32) imm */
/* llilf %dst,imm */