Merge branch 'bpf-improve-test-verifier-coverage'

Alexei Starovoitov says:

====================
BPF verifier has 700+ tests used to check correctness of the verifier.
Beyond checking the verifier log tell kernel to run accepted programs
as well via bpf_prog_test_run() command. That improves quality of the
tests and increases bpf test coverage.
====================

Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>

1 files changed, 49 insertions, 1 deletions

diff --git a/tools/testing/selftests/bpf/test_verifier.c b/tools/testing/selftests/bpf/test_verifier.c
index 960179882a1c..6c22edb1f006 100644
--- a/tools/testing/selftests/bpf/test_verifier.c
+++ b/tools/testing/selftests/bpf/test_verifier.c
@@ -29,6 +29,7 @@
 #include <linux/filter.h>
 #include <linux/bpf_perf_event.h>
 #include <linux/bpf.h>
+#include <linux/if_ether.h>
 
 #include <bpf/bpf.h>
 
@@ -49,6 +50,8 @@
 #define MAX_INSNS       512
 #define MAX_FIXUPS      8
 #define MAX_NR_MAPS     4
+#define POINTER_VALUE   0xcafe4all
+#define TEST_DATA_LEN   64
 
 #define F_NEEDS_EFFICIENT_UNALIGNED_ACCESS      (1 << 0)
 #define F_LOAD_WITH_STRICT_ALIGNMENT            (1 << 1)
@@ -62,6 +65,7 @@ struct bpf_test {
         int fixup_map_in_map[MAX_FIXUPS];
         const char *errstr;
         const char *errstr_unpriv;
+        uint32_t retval;
         enum {
                 UNDEF,
                 ACCEPT,
@@ -95,6 +99,7 @@ static struct bpf_test tests[] = {
                         BPF_EXIT_INSN(),
                 },
                 .result = ACCEPT,
+                .retval = -3,
         },
         {
                 "unreachable",
@@ -210,6 +215,7 @@ static struct bpf_test tests[] = {
                         BPF_EXIT_INSN(),
                 },
                 .result = ACCEPT,
+                .retval = 1,
         },
         {
                 "test8 ld_imm64",
@@ -517,6 +523,7 @@ static struct bpf_test tests[] = {
                 .errstr_unpriv = "R0 leaks addr",
                 .result = ACCEPT,
                 .result_unpriv = REJECT,
+                .retval = POINTER_VALUE,
         },
         {
                 "check valid spill/fill, skb mark",
@@ -803,6 +810,7 @@ static struct bpf_test tests[] = {
                 .errstr_unpriv = "R1 pointer comparison",
                 .result_unpriv = REJECT,
                 .result = ACCEPT,
+                .retval = -ENOENT,
         },
         {
                 "jump test 4",
@@ -1823,6 +1831,7 @@ static struct bpf_test tests[] = {
                         BPF_EXIT_INSN(),
                 },
                 .result = ACCEPT,
+                .retval = 0xfaceb00c,
         },
         {
                 "PTR_TO_STACK store/load - bad alignment on off",
@@ -1881,6 +1890,7 @@ static struct bpf_test tests[] = {
                 .result = ACCEPT,
                 .result_unpriv = REJECT,
                 .errstr_unpriv = "R0 leaks addr",
+                .retval = POINTER_VALUE,
         },
         {
                 "unpriv: add const to pointer",
@@ -2054,6 +2064,7 @@ static struct bpf_test tests[] = {
                         BPF_LDX_MEM(BPF_DW, BPF_REG_1, BPF_REG_6, 0),
                         BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0,
                                      BPF_FUNC_get_hash_recalc),
+                        BPF_MOV64_IMM(BPF_REG_0, 0),
                         BPF_EXIT_INSN(),
                 },
                 .result = ACCEPT,
@@ -2818,6 +2829,7 @@ static struct bpf_test tests[] = {
                 },
                 .result = ACCEPT,
                 .prog_type = BPF_PROG_TYPE_SCHED_CLS,
+                .retval = 1,
         },
         {
                 "direct packet access: test12 (and, good access)",
@@ -2842,6 +2854,7 @@ static struct bpf_test tests[] = {
                 },
                 .result = ACCEPT,
                 .prog_type = BPF_PROG_TYPE_SCHED_CLS,
+                .retval = 1,
         },
         {
                 "direct packet access: test13 (branches, good access)",
@@ -2872,6 +2885,7 @@ static struct bpf_test tests[] = {
                 },
                 .result = ACCEPT,
                 .prog_type = BPF_PROG_TYPE_SCHED_CLS,
+                .retval = 1,
         },
         {
                 "direct packet access: test14 (pkt_ptr += 0, CONST_IMM, good access)",
@@ -2895,6 +2909,7 @@ static struct bpf_test tests[] = {
                 },
                 .result = ACCEPT,
                 .prog_type = BPF_PROG_TYPE_SCHED_CLS,
+                .retval = 1,
         },
         {
                 "direct packet access: test15 (spill with xadd)",
@@ -3181,6 +3196,7 @@ static struct bpf_test tests[] = {
                 },
                 .result = ACCEPT,
                 .prog_type = BPF_PROG_TYPE_SCHED_CLS,
+                .retval = 1,
         },
         {
                 "direct packet access: test28 (marking on <=, bad access)",
@@ -5798,6 +5814,7 @@ static struct bpf_test tests[] = {
                 },
                 .result = ACCEPT,
                 .prog_type = BPF_PROG_TYPE_SCHED_CLS,
+                .retval = 0 /* csum_diff of 64-byte packet */,
         },
         {
                 "helper access to variable memory: size = 0 not allowed on NULL (!ARG_PTR_TO_MEM_OR_NULL)",
@@ -6166,6 +6183,7 @@ static struct bpf_test tests[] = {
                 },
                 .prog_type = BPF_PROG_TYPE_SCHED_CLS,
                 .result = ACCEPT,
+                .retval = 42 /* ultimate return value */,
         },
         {
                 "ld_ind: check calling conv, r1",
@@ -6237,6 +6255,7 @@ static struct bpf_test tests[] = {
                         BPF_EXIT_INSN(),
                 },
                 .result = ACCEPT,
+                .retval = 1,
         },
         {
                 "check bpf_perf_event_data->sample_period byte load permitted",
@@ -7224,6 +7243,7 @@ static struct bpf_test tests[] = {
                 },
                 .fixup_map1 = { 3 },
                 .result = ACCEPT,
+                .retval = POINTER_VALUE,
                 .result_unpriv = REJECT,
                 .errstr_unpriv = "R0 leaks addr as return value"
         },
@@ -7244,6 +7264,7 @@ static struct bpf_test tests[] = {
                 },
                 .fixup_map1 = { 3 },
                 .result = ACCEPT,
+                .retval = POINTER_VALUE,
                 .result_unpriv = REJECT,
                 .errstr_unpriv = "R0 leaks addr as return value"
         },
@@ -7685,6 +7706,7 @@ static struct bpf_test tests[] = {
                         BPF_EXIT_INSN(),
                 },
                 .result = ACCEPT,
+                .retval = TEST_DATA_LEN,
                 .prog_type = BPF_PROG_TYPE_SCHED_CLS,
         },
         {
@@ -8705,6 +8727,7 @@ static struct bpf_test tests[] = {
                 .errstr_unpriv = "function calls to other bpf functions are allowed for root only",
                 .result_unpriv = REJECT,
                 .result = ACCEPT,
+                .retval = 1,
         },
         {
                 "calls: overlapping caller/callee",
@@ -8900,6 +8923,7 @@ static struct bpf_test tests[] = {
                 },
                 .prog_type = BPF_PROG_TYPE_SCHED_ACT,
                 .result = ACCEPT,
+                .retval = TEST_DATA_LEN,
         },
         {
                 "calls: callee using args1",
@@ -8912,6 +8936,7 @@ static struct bpf_test tests[] = {
                 .errstr_unpriv = "allowed for root only",
                 .result_unpriv = REJECT,
                 .result = ACCEPT,
+                .retval = POINTER_VALUE,
         },
         {
                 "calls: callee using wrong args2",
@@ -8942,6 +8967,7 @@ static struct bpf_test tests[] = {
                 .errstr_unpriv = "allowed for root only",
                 .result_unpriv = REJECT,
                 .result = ACCEPT,
+                .retval = TEST_DATA_LEN + TEST_DATA_LEN - ETH_HLEN - ETH_HLEN,
         },
         {
                 "calls: callee changing pkt pointers",
@@ -8990,6 +9016,7 @@ static struct bpf_test tests[] = {
                 },
                 .prog_type = BPF_PROG_TYPE_SCHED_CLS,
                 .result = ACCEPT,
+                .retval = TEST_DATA_LEN + TEST_DATA_LEN,
         },
         {
                 "calls: calls with stack arith",
@@ -9008,6 +9035,7 @@ static struct bpf_test tests[] = {
                 },
                 .prog_type = BPF_PROG_TYPE_SCHED_CLS,
                 .result = ACCEPT,
+                .retval = 42,
         },
         {
                 "calls: calls with misaligned stack access",
@@ -9041,6 +9069,7 @@ static struct bpf_test tests[] = {
                 },
                 .prog_type = BPF_PROG_TYPE_SCHED_CLS,
                 .result = ACCEPT,
+                .retval = 43,
         },
         {
                 "calls: calls control flow, jump test 2",
@@ -9533,6 +9562,7 @@ static struct bpf_test tests[] = {
                 },
                 .prog_type = BPF_PROG_TYPE_XDP,
                 .result = ACCEPT,
+                .retval = 42,
         },
         {
                 "calls: write into callee stack frame",
@@ -10144,6 +10174,7 @@ static struct bpf_test tests[] = {
                 },
                 .result = ACCEPT,
                 .prog_type = BPF_PROG_TYPE_SCHED_CLS,
+                .retval = POINTER_VALUE,
         },
         {
                 "calls: pkt_ptr spill into caller stack 2",
@@ -10209,6 +10240,7 @@ static struct bpf_test tests[] = {
                 },
                 .prog_type = BPF_PROG_TYPE_SCHED_CLS,
                 .result = ACCEPT,
+                .retval = 1,
         },
         {
                 "calls: pkt_ptr spill into caller stack 4",
@@ -10242,6 +10274,7 @@ static struct bpf_test tests[] = {
                 },
                 .prog_type = BPF_PROG_TYPE_SCHED_CLS,
                 .result = ACCEPT,
+                .retval = 1,
         },
         {
                 "calls: pkt_ptr spill into caller stack 5",
@@ -10650,10 +10683,12 @@ static void do_test_single(struct bpf_test *test, bool unpriv,
         int fd_prog, expected_ret, reject_from_alignment;
         struct bpf_insn *prog = test->insns;
         int prog_len = probe_filter_length(prog);
+        char data_in[TEST_DATA_LEN] = {};
         int prog_type = test->prog_type;
         int map_fds[MAX_NR_MAPS];
         const char *expected_err;
-        int i;
+        uint32_t retval;
+        int i, err;
 
         for (i = 0; i < MAX_NR_MAPS; i++)
                 map_fds[i] = -1;
@@ -10696,6 +10731,19 @@ static void do_test_single(struct bpf_test *test, bool unpriv,
                 }
         }
 
+        if (fd_prog >= 0) {
+                err = bpf_prog_test_run(fd_prog, 1, data_in, sizeof(data_in),
+                                        NULL, NULL, &retval, NULL);
+                if (err && errno != 524/*ENOTSUPP*/ && errno != EPERM) {
+                        printf("Unexpected bpf_prog_test_run error\n");
+                        goto fail_log;
+                }
+                if (!err && retval != test->retval &&
+                    test->retval != POINTER_VALUE) {
+                        printf("FAIL retval %d != %d\n", retval, test->retval);
+                        goto fail_log;
+                }
+        }
         (*passes)++;
         printf("OK%s\n", reject_from_alignment ?
                " (NOTE: reject due to unknown alignment)" : "");