Add two more eBPF test cases for JITs, i.e. the second one revealed a bug in the x86_64 JIT compiler, where only an int3 filled image from the allocator was emitted and later wrongly set by the compiler as the bpf_func program code since optimization pass boundary was surpassed w/o actually emitting opcodes.
Interpreter: [ 45.782892] test_bpf: #242 BPF_MAXINSNS: Very long jump backwards jited:0 11 PASS [ 45.783062] test_bpf: #243 BPF_MAXINSNS: Edge hopping nuthouse jited:0 14705 PASS After x86_64 JIT (fixed): [ 80.495638] test_bpf: #242 BPF_MAXINSNS: Very long jump backwards jited:1 6 PASS [ 80.495957] test_bpf: #243 BPF_MAXINSNS: Edge hopping nuthouse jited:1 17157 PASS Reference: http://thread.gmane.org/gmane.linux.network/364729 Signed-off-by: Daniel Borkmann <dan...@iogearbox.net> --- (Testcase to Alexei's patch.) lib/test_bpf.c | 67 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 67 insertions(+) diff --git a/lib/test_bpf.c b/lib/test_bpf.c index 9b012a8..c07b8e7 100644 --- a/lib/test_bpf.c +++ b/lib/test_bpf.c @@ -263,6 +263,57 @@ static int bpf_fill_maxinsns8(struct bpf_test *self) return 0; } +static int bpf_fill_maxinsns9(struct bpf_test *self) +{ + unsigned int len = BPF_MAXINSNS; + struct bpf_insn *insn; + int i; + + insn = kmalloc_array(len, sizeof(*insn), GFP_KERNEL); + if (!insn) + return -ENOMEM; + + insn[0] = BPF_JMP_IMM(BPF_JA, 0, 0, len - 2); + insn[1] = BPF_ALU32_IMM(BPF_MOV, R0, 0xcbababab); + insn[2] = BPF_EXIT_INSN(); + + for (i = 3; i < len - 2; i++) + insn[i] = BPF_ALU32_IMM(BPF_MOV, R0, 0xfefefefe); + + insn[len - 2] = BPF_EXIT_INSN(); + insn[len - 1] = BPF_JMP_IMM(BPF_JA, 0, 0, -(len - 1)); + + self->u.ptr.insns = insn; + self->u.ptr.len = len; + + return 0; +} + +static int bpf_fill_maxinsns10(struct bpf_test *self) +{ + unsigned int len = BPF_MAXINSNS, hlen = len - 2; + struct bpf_insn *insn; + int i; + + insn = kmalloc_array(len, sizeof(*insn), GFP_KERNEL); + if (!insn) + return -ENOMEM; + + for (i = 0; i < hlen / 2; i++) + insn[i] = BPF_JMP_IMM(BPF_JA, 0, 0, hlen - 2 - 2 * i); + for (i = hlen - 1; i > hlen / 2; i--) + insn[i] = BPF_JMP_IMM(BPF_JA, 0, 0, hlen - 1 - 2 * i); + + insn[hlen / 2] = BPF_JMP_IMM(BPF_JA, 0, 0, hlen / 2 - 1); + insn[hlen] = BPF_ALU32_IMM(BPF_MOV, R0, 0xabababac); + insn[hlen + 1] = BPF_EXIT_INSN(); + + self->u.ptr.insns = insn; + self->u.ptr.len = len; + + return 0; +} + static struct bpf_test tests[] = { { "TAX", @@ -4268,6 +4319,22 @@ static struct bpf_test tests[] = { { { 0, 0xffffffff } }, .fill_helper = bpf_fill_maxinsns8, }, + { /* Mainly checking JIT here. */ + "BPF_MAXINSNS: Very long jump backwards", + { }, + INTERNAL | FLAG_NO_DATA, + { }, + { { 0, 0xcbababab } }, + .fill_helper = bpf_fill_maxinsns9, + }, + { /* Mainly checking JIT here. */ + "BPF_MAXINSNS: Edge hopping nuthouse", + { }, + INTERNAL | FLAG_NO_DATA, + { }, + { { 0, 0xabababac } }, + .fill_helper = bpf_fill_maxinsns10, + }, }; static struct net_device dev; -- 1.9.3 -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
