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| author | Ilya Leoshkevich <iii@linux.ibm.com> | 2023-09-19 13:09:07 +0300 |
|---|---|---|
| committer | Alexei Starovoitov <ast@kernel.org> | 2023-09-22 00:21:59 +0300 |
| commit | 738476a079bd238a65c09c63e7437832d96b08e8 (patch) | |
| tree | 722e1729ffef7bbd819061c2fff88571fa93ffe1 /arch/s390/net | |
| parent | 3de55893f6482660e2f04454eb0e65a070523ba0 (diff) | |
| download | linux-738476a079bd238a65c09c63e7437832d96b08e8.tar.xz | |
s390/bpf: Implement BPF_MEMSX
Implement the cpuv4 load with sign-extension, which is encoded as
BPF_MEMSX (and, for internal uses cases only, BPF_PROBE_MEMSX).
This is the same as BPF_MEM and BPF_PROBE_MEM, but with sign
extension instead of zero extension, and s390x has the necessary
instructions: lgb, lgh and lgf.
Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
Link: https://lore.kernel.org/r/20230919101336.2223655-6-iii@linux.ibm.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Diffstat (limited to 'arch/s390/net')
| -rw-r--r-- | arch/s390/net/bpf_jit_comp.c | 32 |
1 files changed, 27 insertions, 5 deletions
diff --git a/arch/s390/net/bpf_jit_comp.c b/arch/s390/net/bpf_jit_comp.c index 6fb24ebb3618..957f5cbba4d8 100644 --- a/arch/s390/net/bpf_jit_comp.c +++ b/arch/s390/net/bpf_jit_comp.c @@ -670,15 +670,18 @@ static void bpf_jit_epilogue(struct bpf_jit *jit, u32 stack_depth) static int get_probe_mem_regno(const u8 *insn) { /* - * insn must point to llgc, llgh, llgf or lg, which have destination - * register at the same position. + * insn must point to llgc, llgh, llgf, lg, lgb, lgh or lgf, which have + * destination register at the same position. */ - if (insn[0] != 0xe3) /* common llgc, llgh, llgf and lg prefix */ + if (insn[0] != 0xe3) /* common prefix */ return -1; if (insn[5] != 0x90 && /* llgc */ insn[5] != 0x91 && /* llgh */ insn[5] != 0x16 && /* llgf */ - insn[5] != 0x04) /* lg */ + insn[5] != 0x04 && /* lg */ + insn[5] != 0x77 && /* lgb */ + insn[5] != 0x15 && /* lgh */ + insn[5] != 0x14) /* lgf */ return -1; return insn[1] >> 4; } @@ -788,7 +791,8 @@ static noinline int bpf_jit_insn(struct bpf_jit *jit, struct bpf_prog *fp, int err; if (BPF_CLASS(insn->code) == BPF_LDX && - BPF_MODE(insn->code) == BPF_PROBE_MEM) + (BPF_MODE(insn->code) == BPF_PROBE_MEM || + BPF_MODE(insn->code) == BPF_PROBE_MEMSX)) probe_prg = jit->prg; switch (insn->code) { @@ -1406,6 +1410,12 @@ static noinline int bpf_jit_insn(struct bpf_jit *jit, struct bpf_prog *fp, if (insn_is_zext(&insn[1])) insn_count = 2; break; + case BPF_LDX | BPF_MEMSX | BPF_B: /* dst = *(s8 *)(ul) (src + off) */ + case BPF_LDX | BPF_PROBE_MEMSX | BPF_B: + /* lgb %dst,0(off,%src) */ + EMIT6_DISP_LH(0xe3000000, 0x0077, dst_reg, src_reg, REG_0, off); + jit->seen |= SEEN_MEM; + break; case BPF_LDX | BPF_MEM | BPF_H: /* dst = *(u16 *)(ul) (src + off) */ case BPF_LDX | BPF_PROBE_MEM | BPF_H: /* llgh %dst,0(off,%src) */ @@ -1414,6 +1424,12 @@ static noinline int bpf_jit_insn(struct bpf_jit *jit, struct bpf_prog *fp, if (insn_is_zext(&insn[1])) insn_count = 2; break; + case BPF_LDX | BPF_MEMSX | BPF_H: /* dst = *(s16 *)(ul) (src + off) */ + case BPF_LDX | BPF_PROBE_MEMSX | BPF_H: + /* lgh %dst,0(off,%src) */ + EMIT6_DISP_LH(0xe3000000, 0x0015, dst_reg, src_reg, REG_0, off); + jit->seen |= SEEN_MEM; + break; case BPF_LDX | BPF_MEM | BPF_W: /* dst = *(u32 *)(ul) (src + off) */ case BPF_LDX | BPF_PROBE_MEM | BPF_W: /* llgf %dst,off(%src) */ @@ -1422,6 +1438,12 @@ static noinline int bpf_jit_insn(struct bpf_jit *jit, struct bpf_prog *fp, if (insn_is_zext(&insn[1])) insn_count = 2; break; + case BPF_LDX | BPF_MEMSX | BPF_W: /* dst = *(s32 *)(ul) (src + off) */ + case BPF_LDX | BPF_PROBE_MEMSX | BPF_W: + /* lgf %dst,off(%src) */ + jit->seen |= SEEN_MEM; + EMIT6_DISP_LH(0xe3000000, 0x0014, dst_reg, src_reg, REG_0, off); + break; case BPF_LDX | BPF_MEM | BPF_DW: /* dst = *(u64 *)(ul) (src + off) */ case BPF_LDX | BPF_PROBE_MEM | BPF_DW: /* lg %dst,0(off,%src) */ |