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| author | Michael Holzheu <holzheu@linux.vnet.ibm.com> | 2015-04-27 11:12:25 +0200 |
|---|---|---|
| committer | Martin Schwidefsky <schwidefsky@de.ibm.com> | 2015-04-30 13:50:34 +0200 |
| commit | 771aada9ace7e5dd837a69ef0bca08b5455b2d36 (patch) | |
| tree | 761f957eb0d7284e4e3e5b549f8ae4d2c57afc0a | |
| parent | 3d99e3fe13d473ac4578c37f477a59b829530764 (diff) | |
| download | linux-771aada9ace7e5dd837a69ef0bca08b5455b2d36.tar.gz | |
s390/bpf: Adjust ALU64_DIV/MOD to match interpreter change
The s390x ALU64_DIV/MOD has been implemented according to the eBPF interpreter specification that used do_div(). This function does a 64-bit by 32-bit divide. It turned out that this was wrong and now the interpreter uses div64_u64_rem() for full 64-bit division. So fix this and use full 64-bit division in the s390x eBPF backend code. Signed-off-by: Michael Holzheu <holzheu@linux.vnet.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
| -rw-r--r-- | arch/s390/net/bpf_jit_comp.c | 14 |
1 files changed, 6 insertions, 8 deletions
diff --git a/arch/s390/net/bpf_jit_comp.c b/arch/s390/net/bpf_jit_comp.c index 7690dc8e1ab5..065aca02bc65 100644 --- a/arch/s390/net/bpf_jit_comp.c +++ b/arch/s390/net/bpf_jit_comp.c @@ -588,8 +588,8 @@ static int bpf_jit_insn(struct bpf_jit *jit, struct bpf_prog *fp, int i) EMIT4(0xb9160000, dst_reg, rc_reg); break; } - case BPF_ALU64 | BPF_DIV | BPF_X: /* dst = dst / (u32) src */ - case BPF_ALU64 | BPF_MOD | BPF_X: /* dst = dst % (u32) src */ + case BPF_ALU64 | BPF_DIV | BPF_X: /* dst = dst / src */ + case BPF_ALU64 | BPF_MOD | BPF_X: /* dst = dst % src */ { int rc_reg = BPF_OP(insn->code) == BPF_DIV ? REG_W1 : REG_W0; @@ -602,10 +602,8 @@ static int bpf_jit_insn(struct bpf_jit *jit, struct bpf_prog *fp, int i) EMIT4_IMM(0xa7090000, REG_W0, 0); /* lgr %w1,%dst */ EMIT4(0xb9040000, REG_W1, dst_reg); - /* llgfr %dst,%src (u32 cast) */ - EMIT4(0xb9160000, dst_reg, src_reg); /* dlgr %w0,%dst */ - EMIT4(0xb9870000, REG_W0, dst_reg); + EMIT4(0xb9870000, REG_W0, src_reg); /* lgr %dst,%rc */ EMIT4(0xb9040000, dst_reg, rc_reg); break; @@ -632,8 +630,8 @@ static int bpf_jit_insn(struct bpf_jit *jit, struct bpf_prog *fp, int i) EMIT4(0xb9160000, dst_reg, rc_reg); break; } - case BPF_ALU64 | BPF_DIV | BPF_K: /* dst = dst / (u32) imm */ - case BPF_ALU64 | BPF_MOD | BPF_K: /* dst = dst % (u32) imm */ + case BPF_ALU64 | BPF_DIV | BPF_K: /* dst = dst / imm */ + case BPF_ALU64 | BPF_MOD | BPF_K: /* dst = dst % imm */ { int rc_reg = BPF_OP(insn->code) == BPF_DIV ? REG_W1 : REG_W0; @@ -649,7 +647,7 @@ static int bpf_jit_insn(struct bpf_jit *jit, struct bpf_prog *fp, int i) EMIT4(0xb9040000, REG_W1, dst_reg); /* dlg %w0,<d(imm)>(%l) */ EMIT6_DISP_LH(0xe3000000, 0x0087, REG_W0, REG_0, REG_L, - EMIT_CONST_U64((u32) imm)); + EMIT_CONST_U64(imm)); /* lgr %dst,%rc */ EMIT4(0xb9040000, dst_reg, rc_reg); break; |