[RFC PATCH v3 bpf-next 3/5] bpf/verifier: update selftests

Edward Cree
2018-04-06T17:14:22Z

Error messages for some bad programs have changed.
Also added a test ("calls: interleaved functions") to ensure that subprogs
are required to be contiguous.
It wasn't entirely clear to me what "calls: wrong recursive calls" was
meant to test for, since all of the JMP|CALL insns are unreachable. I've
changed it so that they are now reachable, which causes static back-edges
to be detected (since that, like insn reachability, is now tested before
subprog boundaries are determined).

Signed-off-by: Edward Cree <ecree@solarflare.com>
---
tools/testing/selftests/bpf/test_verifier.c | 51 ++++++++++++++++++-----------
1 file changed, 32 insertions(+), 19 deletions(-)

diff --git a/tools/testing/selftests/bpf/test_verifier.c b/tools/testing/selftests/bpf/test_verifier.c
index 3e7718b1a9ae..d53522d20072 100644
--- a/tools/testing/selftests/bpf/test_verifier.c
+++ b/tools/testing/selftests/bpf/test_verifier.c
@@ -646,7 +646,7 @@ static struct bpf_test tests[] = {
.insns = {
BPF_ALU64_REG(BPF_MOV, BPF_REG_0, BPF_REG_2),
},
- .errstr = "not an exit",
+ .errstr = "no exit/jump at end of program",
.result = REJECT,
},
{
@@ -9442,13 +9442,13 @@ static struct bpf_test tests[] = {
BPF_EXIT_INSN(),
},
.prog_type = BPF_PROG_TYPE_TRACEPOINT,
- .errstr = "last insn is not an exit or jmp",
+ .errstr = "no exit/jump at end of subprog 0 (insn 0)",
.result = REJECT,
},
{
"calls: wrong recursive calls",
.insns = {
- BPF_JMP_IMM(BPF_JA, 0, 0, 4),
+ BPF_JMP_IMM(BPF_JA, 0, 0, 3),
BPF_JMP_IMM(BPF_JA, 0, 0, 4),
BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 1, 0, -2),
BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 1, 0, -2),
@@ -9457,7 +9457,7 @@ static struct bpf_test tests[] = {
BPF_EXIT_INSN(),
},
.prog_type = BPF_PROG_TYPE_TRACEPOINT,
- .errstr = "jump out of range",
+ .errstr = "jump from insn 0 to 4 crosses",
.result = REJECT,
},
{
@@ -9508,7 +9508,7 @@ static struct bpf_test tests[] = {
BPF_EXIT_INSN(),
},
.prog_type = BPF_PROG_TYPE_TRACEPOINT,
- .errstr = "jump out of range",
+ .errstr = "jump from insn 1 to 5 crosses",
.result = REJECT,
},
{
@@ -9787,7 +9787,7 @@ static struct bpf_test tests[] = {
BPF_EXIT_INSN(),
},
.prog_type = BPF_PROG_TYPE_SCHED_CLS,
- .errstr = "jump out of range from insn 1 to 4",
+ .errstr = "jump from insn 1 to 4 crosses",
.result = REJECT,
},
{
@@ -9803,13 +9803,12 @@ static struct bpf_test tests[] = {
BPF_ALU64_REG(BPF_ADD, BPF_REG_7, BPF_REG_0),
BPF_MOV64_REG(BPF_REG_0, BPF_REG_7),
BPF_EXIT_INSN(),
- BPF_LDX_MEM(BPF_W, BPF_REG_0, BPF_REG_1,
- offsetof(struct __sk_buff, len)),
+ BPF_LDX_MEM(BPF_DW, BPF_REG_0, BPF_REG_1, 8),
BPF_JMP_IMM(BPF_JEQ, BPF_REG_0, 0, -3),
BPF_EXIT_INSN(),
},
.prog_type = BPF_PROG_TYPE_TRACEPOINT,
- .errstr = "jump out of range from insn 11 to 9",
+ .errstr = "jump from insn 11 to 9 crosses",
.result = REJECT,
},
{
@@ -9861,7 +9860,7 @@ static struct bpf_test tests[] = {
BPF_EXIT_INSN(),
},
.prog_type = BPF_PROG_TYPE_TRACEPOINT,
- .errstr = "invalid destination",
+ .errstr = "call to invalid destination",
.result = REJECT,
},
{
@@ -9873,7 +9872,7 @@ static struct bpf_test tests[] = {
BPF_EXIT_INSN(),
},
.prog_type = BPF_PROG_TYPE_TRACEPOINT,
- .errstr = "invalid destination",
+ .errstr = "call to invalid destination",
.result = REJECT,
},
{
@@ -9886,7 +9885,7 @@ static struct bpf_test tests[] = {
BPF_EXIT_INSN(),
},
.prog_type = BPF_PROG_TYPE_TRACEPOINT,
- .errstr = "jump out of range",
+ .errstr = "jump from insn 3 to 1 crosses",
.result = REJECT,
},
{
@@ -9899,7 +9898,7 @@ static struct bpf_test tests[] = {
BPF_EXIT_INSN(),
},
.prog_type = BPF_PROG_TYPE_TRACEPOINT,
- .errstr = "jump out of range",
+ .errstr = "jump from insn 0 to 4 crosses",
.result = REJECT,
},
{
@@ -9913,7 +9912,7 @@ static struct bpf_test tests[] = {
BPF_JMP_IMM(BPF_JEQ, BPF_REG_1, 0, -2),
},
.prog_type = BPF_PROG_TYPE_TRACEPOINT,
- .errstr = "not an exit",
+ .errstr = "no exit/jump at end of program",
.result = REJECT,
},
{
@@ -9927,7 +9926,7 @@ static struct bpf_test tests[] = {
BPF_EXIT_INSN(),
},
.prog_type = BPF_PROG_TYPE_TRACEPOINT,
- .errstr = "last insn",
+ .errstr = "no exit/jump at end of subprog",
.result = REJECT,
},
{
@@ -9942,7 +9941,7 @@ static struct bpf_test tests[] = {
BPF_EXIT_INSN(),
},
.prog_type = BPF_PROG_TYPE_TRACEPOINT,
- .errstr = "last insn",
+ .errstr = "no exit/jump at end of subprog",
.result = REJECT,
},
{
@@ -9982,12 +9981,11 @@ static struct bpf_test tests[] = {
BPF_ALU64_REG(BPF_ADD, BPF_REG_7, BPF_REG_0),
BPF_MOV64_REG(BPF_REG_0, BPF_REG_7),
BPF_MOV64_REG(BPF_REG_0, BPF_REG_0),
- BPF_LDX_MEM(BPF_W, BPF_REG_0, BPF_REG_1,
- offsetof(struct __sk_buff, len)),
+ BPF_LDX_MEM(BPF_DW, BPF_REG_0, BPF_REG_1, 8),
BPF_EXIT_INSN(),
},
.prog_type = BPF_PROG_TYPE_TRACEPOINT,
- .errstr = "not an exit",
+ .errstr = "no exit/jump at end of subprog",
.result = REJECT,
},
{
@@ -11423,6 +11421,21 @@ static struct bpf_test tests[] = {
.errstr = "BPF_XADD stores into R2 packet",
.prog_type = BPF_PROG_TYPE_XDP,
},
+ {
+ "calls: interleaved functions",
+ .insns = {
+ BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 1, 0, 2),
+ BPF_MOV64_IMM(BPF_REG_0, 1),
+ BPF_JMP_IMM(BPF_JA, 0, 0, 2),
+ BPF_MOV64_IMM(BPF_REG_0, 2),
+ BPF_JMP_IMM(BPF_JA, 0, 0, 1),
+ BPF_EXIT_INSN(),
+ BPF_EXIT_INSN(),
+ },
+ .prog_type = BPF_PROG_TYPE_TRACEPOINT,
+ .errstr = "jump from insn 2 to 5 crosses",
+ .result = REJECT,
+ },
};

static int probe_filter_length(const struct bpf_insn *fp)