test_bpf: add more eBPF jump torture cases
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 <daniel@iogearbox.net>
Acked-by: Alexei Starovoitov <ast@plumgrid.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
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 @@
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 @@
{ { 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;