From: Alexei Starovoitov <ast@kernel.org>
To: <davem@davemloft.net>
Cc: <daniel@iogearbox.net>, <netdev@vger.kernel.org>,
<bpf@vger.kernel.org>, <kernel-team@fb.com>
Subject: [PATCH bpf-next 3/4] selftests/bpf: verifier precise tests
Date: Thu, 22 Aug 2019 22:52:14 -0700 [thread overview]
Message-ID: <20190823055215.2658669-4-ast@kernel.org> (raw)
In-Reply-To: <20190823055215.2658669-1-ast@kernel.org>
Use BPF_F_TEST_STATE_FREQ flag to check that precision
tracking works as expected by comparing every step it takes.
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
---
tools/testing/selftests/bpf/test_verifier.c | 68 ++++++++--
.../testing/selftests/bpf/verifier/precise.c | 117 ++++++++++++++++++
2 files changed, 174 insertions(+), 11 deletions(-)
create mode 100644 tools/testing/selftests/bpf/verifier/precise.c
diff --git a/tools/testing/selftests/bpf/test_verifier.c b/tools/testing/selftests/bpf/test_verifier.c
index 44e2d640b088..d27fd929abb9 100644
--- a/tools/testing/selftests/bpf/test_verifier.c
+++ b/tools/testing/selftests/bpf/test_verifier.c
@@ -61,6 +61,7 @@
#define UNPRIV_SYSCTL "kernel/unprivileged_bpf_disabled"
static bool unpriv_disabled = false;
static int skips;
+static bool verbose = false;
struct bpf_test {
const char *descr;
@@ -92,7 +93,8 @@ struct bpf_test {
enum {
UNDEF,
ACCEPT,
- REJECT
+ REJECT,
+ VERBOSE_ACCEPT,
} result, result_unpriv;
enum bpf_prog_type prog_type;
uint8_t flags;
@@ -859,6 +861,36 @@ static int do_prog_test_run(int fd_prog, bool unpriv, uint32_t expected_val,
return 0;
}
+static bool cmp_str_seq(const char *log, const char *exp)
+{
+ char needle[80];
+ const char *p, *q;
+ int len;
+
+ do {
+ p = strchr(exp, '\t');
+ if (!p)
+ p = exp + strlen(exp);
+
+ len = p - exp;
+ if (len >= sizeof(needle) || !len) {
+ printf("FAIL\nTestcase bug\n");
+ return false;
+ }
+ strncpy(needle, exp, len);
+ needle[len] = 0;
+ q = strstr(log, needle);
+ if (!q) {
+ printf("FAIL\nUnexpected verifier log in successful load!\n"
+ "EXP: %s\nRES:\n", needle);
+ return false;
+ }
+ log = q + len;
+ exp = p + 1;
+ } while (*p);
+ return true;
+}
+
static void do_test_single(struct bpf_test *test, bool unpriv,
int *passes, int *errors)
{
@@ -897,14 +929,20 @@ static void do_test_single(struct bpf_test *test, bool unpriv,
pflags |= BPF_F_STRICT_ALIGNMENT;
if (test->flags & F_NEEDS_EFFICIENT_UNALIGNED_ACCESS)
pflags |= BPF_F_ANY_ALIGNMENT;
+ if (test->flags & ~3)
+ pflags |= test->flags;
+ expected_ret = unpriv && test->result_unpriv != UNDEF ?
+ test->result_unpriv : test->result;
+ expected_err = unpriv && test->errstr_unpriv ?
+ test->errstr_unpriv : test->errstr;
memset(&attr, 0, sizeof(attr));
attr.prog_type = prog_type;
attr.expected_attach_type = test->expected_attach_type;
attr.insns = prog;
attr.insns_cnt = prog_len;
attr.license = "GPL";
- attr.log_level = 4;
+ attr.log_level = verbose || expected_ret == VERBOSE_ACCEPT ? 1 : 4;
attr.prog_flags = pflags;
fd_prog = bpf_load_program_xattr(&attr, bpf_vlog, sizeof(bpf_vlog));
@@ -914,14 +952,9 @@ static void do_test_single(struct bpf_test *test, bool unpriv,
goto close_fds;
}
- expected_ret = unpriv && test->result_unpriv != UNDEF ?
- test->result_unpriv : test->result;
- expected_err = unpriv && test->errstr_unpriv ?
- test->errstr_unpriv : test->errstr;
-
alignment_prevented_execution = 0;
- if (expected_ret == ACCEPT) {
+ if (expected_ret == ACCEPT || expected_ret == VERBOSE_ACCEPT) {
if (fd_prog < 0) {
printf("FAIL\nFailed to load prog '%s'!\n",
strerror(errno));
@@ -932,6 +965,9 @@ static void do_test_single(struct bpf_test *test, bool unpriv,
(test->flags & F_NEEDS_EFFICIENT_UNALIGNED_ACCESS))
alignment_prevented_execution = 1;
#endif
+ if (expected_ret == VERBOSE_ACCEPT && !cmp_str_seq(bpf_vlog, expected_err)) {
+ goto fail_log;
+ }
} else {
if (fd_prog >= 0) {
printf("FAIL\nUnexpected success to load!\n");
@@ -957,6 +993,9 @@ static void do_test_single(struct bpf_test *test, bool unpriv,
}
}
+ if (verbose)
+ printf(", verifier log:\n%s", bpf_vlog);
+
run_errs = 0;
run_successes = 0;
if (!alignment_prevented_execution && fd_prog >= 0) {
@@ -1097,17 +1136,24 @@ int main(int argc, char **argv)
{
unsigned int from = 0, to = ARRAY_SIZE(tests);
bool unpriv = !is_admin();
+ int arg = 1;
+
+ if (argc > 1 && strcmp(argv[1], "-v") == 0) {
+ arg++;
+ verbose = true;
+ argc--;
+ }
if (argc == 3) {
- unsigned int l = atoi(argv[argc - 2]);
- unsigned int u = atoi(argv[argc - 1]);
+ unsigned int l = atoi(argv[arg]);
+ unsigned int u = atoi(argv[arg + 1]);
if (l < to && u < to) {
from = l;
to = u + 1;
}
} else if (argc == 2) {
- unsigned int t = atoi(argv[argc - 1]);
+ unsigned int t = atoi(argv[arg]);
if (t < to) {
from = t;
diff --git a/tools/testing/selftests/bpf/verifier/precise.c b/tools/testing/selftests/bpf/verifier/precise.c
new file mode 100644
index 000000000000..a20953c23721
--- /dev/null
+++ b/tools/testing/selftests/bpf/verifier/precise.c
@@ -0,0 +1,117 @@
+{
+ "precise: test 1",
+ .insns = {
+ BPF_MOV64_IMM(BPF_REG_0, 1),
+ BPF_LD_MAP_FD(BPF_REG_6, 0),
+ BPF_MOV64_REG(BPF_REG_1, BPF_REG_6),
+ BPF_MOV64_REG(BPF_REG_2, BPF_REG_FP),
+ BPF_ALU64_IMM(BPF_ADD, BPF_REG_2, -8),
+ BPF_ST_MEM(BPF_DW, BPF_REG_FP, -8, 0),
+ BPF_EMIT_CALL(BPF_FUNC_map_lookup_elem),
+ BPF_JMP_IMM(BPF_JNE, BPF_REG_0, 0, 1),
+ BPF_EXIT_INSN(),
+
+ BPF_MOV64_REG(BPF_REG_9, BPF_REG_0),
+
+ BPF_MOV64_REG(BPF_REG_1, BPF_REG_6),
+ BPF_MOV64_REG(BPF_REG_2, BPF_REG_FP),
+ BPF_ALU64_IMM(BPF_ADD, BPF_REG_2, -8),
+ BPF_EMIT_CALL(BPF_FUNC_map_lookup_elem),
+ BPF_JMP_IMM(BPF_JNE, BPF_REG_0, 0, 1),
+ BPF_EXIT_INSN(),
+
+ BPF_MOV64_REG(BPF_REG_8, BPF_REG_0),
+
+ BPF_ALU64_REG(BPF_SUB, BPF_REG_9, BPF_REG_8), /* map_value_ptr -= map_value_ptr */
+ BPF_MOV64_REG(BPF_REG_2, BPF_REG_9),
+ BPF_JMP_IMM(BPF_JLT, BPF_REG_2, 8, 1),
+ BPF_EXIT_INSN(),
+
+ BPF_ALU64_IMM(BPF_ADD, BPF_REG_2, 1), /* R2=inv(umin=1, umax=8) */
+ BPF_MOV64_REG(BPF_REG_1, BPF_REG_FP),
+ BPF_ALU64_IMM(BPF_ADD, BPF_REG_1, -8),
+ BPF_MOV64_IMM(BPF_REG_3, 0),
+ BPF_EMIT_CALL(BPF_FUNC_probe_read),
+ BPF_EXIT_INSN(),
+ },
+ .prog_type = BPF_PROG_TYPE_TRACEPOINT,
+ .fixup_map_array_48b = { 1 },
+ .result = VERBOSE_ACCEPT,
+ .errstr =
+ "26: (85) call bpf_probe_read#4\
+ last_idx 26 first_idx 20\
+ regs=4 stack=0 before 25\
+ regs=4 stack=0 before 24\
+ regs=4 stack=0 before 23\
+ regs=4 stack=0 before 22\
+ regs=4 stack=0 before 20\
+ parent didn't have regs=4 stack=0 marks\
+ last_idx 19 first_idx 10\
+ regs=4 stack=0 before 19\
+ regs=200 stack=0 before 18\
+ regs=300 stack=0 before 17\
+ regs=201 stack=0 before 15\
+ regs=201 stack=0 before 14\
+ regs=200 stack=0 before 13\
+ regs=200 stack=0 before 12\
+ regs=200 stack=0 before 11\
+ regs=200 stack=0 before 10\
+ parent already had regs=0 stack=0 marks",
+},
+{
+ "precise: test 2",
+ .insns = {
+ BPF_MOV64_IMM(BPF_REG_0, 1),
+ BPF_LD_MAP_FD(BPF_REG_6, 0),
+ BPF_MOV64_REG(BPF_REG_1, BPF_REG_6),
+ BPF_MOV64_REG(BPF_REG_2, BPF_REG_FP),
+ BPF_ALU64_IMM(BPF_ADD, BPF_REG_2, -8),
+ BPF_ST_MEM(BPF_DW, BPF_REG_FP, -8, 0),
+ BPF_EMIT_CALL(BPF_FUNC_map_lookup_elem),
+ BPF_JMP_IMM(BPF_JNE, BPF_REG_0, 0, 1),
+ BPF_EXIT_INSN(),
+
+ BPF_MOV64_REG(BPF_REG_9, BPF_REG_0),
+
+ BPF_MOV64_REG(BPF_REG_1, BPF_REG_6),
+ BPF_MOV64_REG(BPF_REG_2, BPF_REG_FP),
+ BPF_ALU64_IMM(BPF_ADD, BPF_REG_2, -8),
+ BPF_EMIT_CALL(BPF_FUNC_map_lookup_elem),
+ BPF_JMP_IMM(BPF_JNE, BPF_REG_0, 0, 1),
+ BPF_EXIT_INSN(),
+
+ BPF_MOV64_REG(BPF_REG_8, BPF_REG_0),
+
+ BPF_ALU64_REG(BPF_SUB, BPF_REG_9, BPF_REG_8), /* map_value_ptr -= map_value_ptr */
+ BPF_MOV64_REG(BPF_REG_2, BPF_REG_9),
+ BPF_JMP_IMM(BPF_JLT, BPF_REG_2, 8, 1),
+ BPF_EXIT_INSN(),
+
+ BPF_ALU64_IMM(BPF_ADD, BPF_REG_2, 1), /* R2=inv(umin=1, umax=8) */
+ BPF_MOV64_REG(BPF_REG_1, BPF_REG_FP),
+ BPF_ALU64_IMM(BPF_ADD, BPF_REG_1, -8),
+ BPF_MOV64_IMM(BPF_REG_3, 0),
+ BPF_EMIT_CALL(BPF_FUNC_probe_read),
+ BPF_EXIT_INSN(),
+ },
+ .prog_type = BPF_PROG_TYPE_TRACEPOINT,
+ .fixup_map_array_48b = { 1 },
+ .result = VERBOSE_ACCEPT,
+ .flags = BPF_F_TEST_STATE_FREQ,
+ .errstr =
+ "26: (85) call bpf_probe_read#4\
+ last_idx 26 first_idx 22\
+ regs=4 stack=0 before 25\
+ regs=4 stack=0 before 24\
+ regs=4 stack=0 before 23\
+ regs=4 stack=0 before 22\
+ parent didn't have regs=4 stack=0 marks\
+ last_idx 20 first_idx 20\
+ regs=4 stack=0 before 20\
+ parent didn't have regs=4 stack=0 marks\
+ last_idx 19 first_idx 17\
+ regs=4 stack=0 before 19\
+ regs=200 stack=0 before 18\
+ regs=300 stack=0 before 17\
+ parent already had regs=0 stack=0 marks",
+},
--
2.20.0
next prev parent reply other threads:[~2019-08-23 5:52 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-08-23 5:52 [PATCH bpf-next 0/4] bpf: precision tracking tests Alexei Starovoitov
2019-08-23 5:52 ` [PATCH bpf-next 1/4] bpf: introduce verifier internal test flag Alexei Starovoitov
2019-08-26 5:09 ` Song Liu
2019-08-23 5:52 ` [PATCH bpf-next 2/4] tools/bpf: sync bpf.h Alexei Starovoitov
2019-08-26 5:10 ` Song Liu
2019-08-23 5:52 ` Alexei Starovoitov [this message]
2019-08-26 5:22 ` [PATCH bpf-next 3/4] selftests/bpf: verifier precise tests Song Liu
2019-08-26 22:47 ` Alexei Starovoitov
2019-08-26 22:51 ` Song Liu
2019-08-23 5:52 ` [PATCH bpf-next 4/4] selftests/bpf: add precision tracking test Alexei Starovoitov
2019-08-26 5:33 ` Song Liu
2019-08-27 22:43 ` [PATCH bpf-next 0/4] bpf: precision tracking tests Daniel Borkmann
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20190823055215.2658669-4-ast@kernel.org \
--to=ast@kernel.org \
--cc=bpf@vger.kernel.org \
--cc=daniel@iogearbox.net \
--cc=davem@davemloft.net \
--cc=kernel-team@fb.com \
--cc=netdev@vger.kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.