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| author |   William Tu <u9012063@gmail.com> | 2017-02-04 08:37:29 -0800 |
|---|---|---|
| committer |   David S. Miller <davem@davemloft.net> | 2017-02-06 22:50:04 -0500 |
| commit | 63dfef75ed75364901d7caa52c6420cec3e73519 (patch) | |
| tree | 8c3065d18a1b80da112ec1ee9a1074240cd100ca /tools | |
| parent | bpf: test for AND edge cases (diff) | |
| download | linux-dev-63dfef75ed75364901d7caa52c6420cec3e73519.tar.xz linux-dev-63dfef75ed75364901d7caa52c6420cec3e73519.zip | |
bpf: enable verifier to add 0 to packet ptr
The patch fixes the case when adding a zero value to the packet
pointer. The zero value could come from src_reg equals type
BPF_K or CONST_IMM. The patch fixes both, otherwise the verifer
reports the following error:
[...]
R0=imm0,min_value=0,max_value=0
R1=pkt(id=0,off=0,r=4)
R2=pkt_end R3=fp-12
R4=imm4,min_value=4,max_value=4
R5=pkt(id=0,off=4,r=4)
269: (bf) r2 = r0 // r2 becomes imm0
270: (77) r2 >>= 3
271: (bf) r4 = r1 // r4 becomes pkt ptr
272: (0f) r4 += r2 // r4 += 0
addition of negative constant to packet pointer is not allowed
Signed-off-by: William Tu <u9012063@gmail.com>
Signed-off-by: Mihai Budiu <mbudiu@vmware.com>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: Alexei Starovoitov <ast@kernel.org>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'tools')
| -rw-r--r-- | tools/testing/selftests/bpf/test_verifier.c | 23 |
1 files changed, 23 insertions, 0 deletions
diff --git a/tools/testing/selftests/bpf/test_verifier.c b/tools/testing/selftests/bpf/test_verifier.c index df194e1d56c2..71f6407cde60 100644 --- a/tools/testing/selftests/bpf/test_verifier.c +++ b/tools/testing/selftests/bpf/test_verifier.c @@ -2404,6 +2404,29 @@ static struct bpf_test tests[] = { .prog_type = BPF_PROG_TYPE_SCHED_CLS, }, { + "direct packet access: test14 (pkt_ptr += 0, CONST_IMM, good access)", + .insns = { + BPF_LDX_MEM(BPF_W, BPF_REG_2, BPF_REG_1, + offsetof(struct __sk_buff, data)), + BPF_LDX_MEM(BPF_W, BPF_REG_3, BPF_REG_1, + offsetof(struct __sk_buff, data_end)), + BPF_MOV64_REG(BPF_REG_0, BPF_REG_2), + BPF_ALU64_IMM(BPF_ADD, BPF_REG_0, 22), + BPF_JMP_REG(BPF_JGT, BPF_REG_0, BPF_REG_3, 7), + BPF_MOV64_IMM(BPF_REG_5, 12), + BPF_ALU64_IMM(BPF_RSH, BPF_REG_5, 4), + BPF_MOV64_REG(BPF_REG_6, BPF_REG_2), + BPF_ALU64_REG(BPF_ADD, BPF_REG_6, BPF_REG_5), + BPF_LDX_MEM(BPF_B, BPF_REG_0, BPF_REG_6, 0), + BPF_MOV64_IMM(BPF_REG_0, 1), + BPF_EXIT_INSN(), + BPF_MOV64_IMM(BPF_REG_0, 0), + BPF_EXIT_INSN(), + }, + .result = ACCEPT, + .prog_type = BPF_PROG_TYPE_SCHED_CLS, + }, + { "helper access to packet: test1, valid packet_ptr range", .insns = { BPF_LDX_MEM(BPF_W, BPF_REG_2, BPF_REG_1, |