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| author | Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com> | 2021-11-15 16:36:02 +0530 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2021-11-17 09:48:49 +0100 |
| commit | 84b3fbfd8ed8348c29fc20ee9314754b31b559e5 (patch) | |
| tree | 87ac22ae6a7a33b2d54d7c172e640dab2ac35b8e | |
| parent | 7edda4bd9eb9e36860375509331c7ed9ef326685 (diff) | |
| download | linux-84b3fbfd8ed8348c29fc20ee9314754b31b559e5.tar.gz linux-84b3fbfd8ed8348c29fc20ee9314754b31b559e5.tar.bz2 linux-84b3fbfd8ed8348c29fc20ee9314754b31b559e5.zip | |
powerpc/bpf: Fix BPF_SUB when imm == 0x80000000
upstream commit 5855c4c1f415ca3ba1046e77c0b3d3dfc96c9025
We aren't handling subtraction involving an immediate value of
0x80000000 properly. Fix the same.
Fixes: 156d0e290e969c ("powerpc/ebpf/jit: Implement JIT compiler for extended BPF")
Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Reviewed-by: Christophe Leroy <christophe.leroy@csgroup.eu>
[mpe: Fold in fix from Naveen to use imm <= 32768]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/fc4b1276eb10761fd7ce0814c8dd089da2815251.1633464148.git.naveen.n.rao@linux.vnet.ibm.com
[adjust macros to account for commits 0654186510a40e and 3a181237916310]
Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | arch/powerpc/net/bpf_jit_comp64.c | 27 |
1 files changed, 17 insertions, 10 deletions
diff --git a/arch/powerpc/net/bpf_jit_comp64.c b/arch/powerpc/net/bpf_jit_comp64.c index ec1d01654f40..b5a0c3a3ce6e 100644 --- a/arch/powerpc/net/bpf_jit_comp64.c +++ b/arch/powerpc/net/bpf_jit_comp64.c @@ -349,18 +349,25 @@ static int bpf_jit_build_body(struct bpf_prog *fp, u32 *image, PPC_SUB(dst_reg, dst_reg, src_reg); goto bpf_alu32_trunc; case BPF_ALU | BPF_ADD | BPF_K: /* (u32) dst += (u32) imm */ - case BPF_ALU | BPF_SUB | BPF_K: /* (u32) dst -= (u32) imm */ case BPF_ALU64 | BPF_ADD | BPF_K: /* dst += imm */ + if (!imm) { + goto bpf_alu32_trunc; + } else if (imm >= -32768 && imm < 32768) { + PPC_ADDI(dst_reg, dst_reg, IMM_L(imm)); + } else { + PPC_LI32(b2p[TMP_REG_1], imm); + PPC_ADD(dst_reg, dst_reg, b2p[TMP_REG_1]); + } + goto bpf_alu32_trunc; + case BPF_ALU | BPF_SUB | BPF_K: /* (u32) dst -= (u32) imm */ case BPF_ALU64 | BPF_SUB | BPF_K: /* dst -= imm */ - if (BPF_OP(code) == BPF_SUB) - imm = -imm; - if (imm) { - if (imm >= -32768 && imm < 32768) - PPC_ADDI(dst_reg, dst_reg, IMM_L(imm)); - else { - PPC_LI32(b2p[TMP_REG_1], imm); - PPC_ADD(dst_reg, dst_reg, b2p[TMP_REG_1]); - } + if (!imm) { + goto bpf_alu32_trunc; + } else if (imm > -32768 && imm <= 32768) { + PPC_ADDI(dst_reg, dst_reg, IMM_L(-imm)); + } else { + PPC_LI32(b2p[TMP_REG_1], imm); + PPC_SUB(dst_reg, dst_reg, b2p[TMP_REG_1]); } goto bpf_alu32_trunc; case BPF_ALU | BPF_MUL | BPF_X: /* (u32) dst *= (u32) src */ |