[PATCH v2 bpf-next 4/4] selftests/bpf: add dump type data tests to btf dump tests
From: Alan Maguire
Date: Sun Jan 17 2021 - 17:22:33 EST
Test various type data dumping operations by comparing expected
format with the dumped string; an snprintf-style printf function
is used to record the string dumped.
Signed-off-by: Alan Maguire <alan.maguire@xxxxxxxxxx>
---
tools/testing/selftests/bpf/prog_tests/btf_dump.c | 233 ++++++++++++++++++++++
1 file changed, 233 insertions(+)
diff --git a/tools/testing/selftests/bpf/prog_tests/btf_dump.c b/tools/testing/selftests/bpf/prog_tests/btf_dump.c
index c60091e..262561f4 100644
--- a/tools/testing/selftests/bpf/prog_tests/btf_dump.c
+++ b/tools/testing/selftests/bpf/prog_tests/btf_dump.c
@@ -232,6 +232,237 @@ void test_btf_dump_incremental(void)
btf__free(btf);
}
+#define STRSIZE 2048
+#define EXPECTED_STRSIZE 256
+
+void btf_dump_snprintf(void *ctx, const char *fmt, va_list args)
+{
+ char *s = ctx, new[STRSIZE];
+
+ vsnprintf(new, STRSIZE, fmt, args);
+ strncat(s, new, STRSIZE);
+ vfprintf(ctx, fmt, args);
+}
+
+/* skip "enum "/"struct " prefixes */
+#define SKIP_PREFIX(_typestr, _prefix) \
+ do { \
+ if (strstr(_typestr, _prefix) == _typestr) \
+ _typestr += strlen(_prefix) + 1; \
+ } while (0)
+
+int btf_dump_data(struct btf *btf, struct btf_dump *d,
+ char *ptrtype, __u64 flags, void *ptr,
+ char *str, char *expectedval)
+{
+ struct btf_dump_emit_type_data_opts opts = { 0 };
+ int ret = 0, cmp;
+ __s32 type_id;
+
+ opts.sz = sizeof(opts);
+ opts.compact = true;
+ if (flags & BTF_F_NONAME)
+ opts.noname = true;
+ if (flags & BTF_F_ZERO)
+ opts.zero = true;
+ SKIP_PREFIX(ptrtype, "enum");
+ SKIP_PREFIX(ptrtype, "struct");
+ SKIP_PREFIX(ptrtype, "union");
+ type_id = btf__find_by_name(btf, ptrtype);
+ if (CHECK(type_id <= 0, "find type id",
+ "no '%s' in BTF: %d\n", ptrtype, type_id)) {
+ ret = -ENOENT;
+ goto err;
+ }
+ str[0] = '\0';
+ ret = btf_dump__emit_type_data(d, type_id, &opts, ptr);
+ if (CHECK(ret < 0, "btf_dump__emit_type_data",
+ "failed: %d\n", ret))
+ goto err;
+
+ cmp = strncmp(str, expectedval, EXPECTED_STRSIZE);
+ if (CHECK(cmp, "ensure expected/actual match",
+ "'%s' does not match expected '%s': %d\n",
+ str, expectedval, cmp))
+ ret = -EFAULT;
+
+err:
+ if (ret)
+ btf_dump__free(d);
+ return ret;
+}
+
+#define TEST_BTF_DUMP_DATA(_b, _d, _str, _type, _flags, _expected, ...) \
+ do { \
+ char _expectedval[EXPECTED_STRSIZE] = _expected; \
+ char __ptrtype[64] = #_type; \
+ char *_ptrtype = (char *)__ptrtype; \
+ static _type _ptrdata = __VA_ARGS__; \
+ void *_ptr = &_ptrdata; \
+ \
+ if (btf_dump_data(_b, _d, _ptrtype, _flags, _ptr, \
+ _str, _expectedval)) \
+ return; \
+ } while (0)
+
+/* Use where expected data string matches its stringified declaration */
+#define TEST_BTF_DUMP_DATA_C(_b, _d, _str, _type, _opts, ...) \
+ TEST_BTF_DUMP_DATA(_b, _d, _str, _type, _opts, \
+ "(" #_type ")" #__VA_ARGS__, __VA_ARGS__)
+
+void test_btf_dump_data(void)
+{
+ struct btf *btf = libbpf_find_kernel_btf();
+ char str[STRSIZE];
+ struct btf_dump_opts opts = { .ctx = str };
+ struct btf_dump *d;
+
+ if (CHECK(!btf, "get kernel BTF", "no kernel BTF found"))
+ return;
+
+ d = btf_dump__new(btf, NULL, &opts, btf_dump_snprintf);
+
+ if (CHECK(!d, "new dump", "could not create BTF dump"))
+ return;
+
+ /* Verify type display for various types. */
+
+ /* simple int */
+ TEST_BTF_DUMP_DATA_C(btf, d, str, int, 0, 1234);
+ TEST_BTF_DUMP_DATA(btf, d, str, int, BTF_F_NONAME, "1234", 1234);
+
+ /* zero value should be printed at toplevel */
+ TEST_BTF_DUMP_DATA(btf, d, str, int, 0, "(int)0", 0);
+ TEST_BTF_DUMP_DATA(btf, d, str, int, BTF_F_NONAME, "0", 0);
+ TEST_BTF_DUMP_DATA(btf, d, str, int, BTF_F_ZERO, "(int)0", 0);
+ TEST_BTF_DUMP_DATA(btf, d, str, int, BTF_F_NONAME | BTF_F_ZERO,
+ "0", 0);
+ TEST_BTF_DUMP_DATA_C(btf, d, str, int, 0, -4567);
+ TEST_BTF_DUMP_DATA(btf, d, str, int, BTF_F_NONAME, "-4567", -4567);
+
+ /* simple char */
+ TEST_BTF_DUMP_DATA_C(btf, d, str, char, 0, 100);
+ TEST_BTF_DUMP_DATA(btf, d, str, char, BTF_F_NONAME, "100", 100);
+ /* zero value should be printed at toplevel */
+ TEST_BTF_DUMP_DATA(btf, d, str, char, 0, "(char)0", 0);
+ TEST_BTF_DUMP_DATA(btf, d, str, char, BTF_F_NONAME, "0", 0);
+ TEST_BTF_DUMP_DATA(btf, d, str, char, BTF_F_ZERO, "(char)0", 0);
+ TEST_BTF_DUMP_DATA(btf, d, str, char, BTF_F_NONAME | BTF_F_ZERO,
+ "0", 0);
+
+ /* simple typedef */
+ TEST_BTF_DUMP_DATA_C(btf, d, str, uint64_t, 0, 100);
+ TEST_BTF_DUMP_DATA(btf, d, str, u64, BTF_F_NONAME, "1", 1);
+ /* zero value should be printed at toplevel */
+ TEST_BTF_DUMP_DATA(btf, d, str, u64, 0, "(u64)0", 0);
+ TEST_BTF_DUMP_DATA(btf, d, str, u64, BTF_F_NONAME, "0", 0);
+ TEST_BTF_DUMP_DATA(btf, d, str, u64, BTF_F_ZERO, "(u64)0", 0);
+ TEST_BTF_DUMP_DATA(btf, d, str, u64, BTF_F_NONAME | BTF_F_ZERO,
+ "0", 0);
+
+ /* typedef struct */
+ TEST_BTF_DUMP_DATA_C(btf, d, str, atomic_t, 0, {.counter = (int)1,});
+ TEST_BTF_DUMP_DATA(btf, d, str, atomic_t, BTF_F_NONAME, "{1,}",
+ {.counter = 1,});
+ /* typedef with 0 value should be printed at toplevel */
+ TEST_BTF_DUMP_DATA(btf, d, str, atomic_t, 0, "(atomic_t){}",
+ {.counter = 0,});
+ TEST_BTF_DUMP_DATA(btf, d, str, atomic_t, BTF_F_NONAME, "{}",
+ {.counter = 0,});
+ TEST_BTF_DUMP_DATA(btf, d, str, atomic_t, BTF_F_ZERO,
+ "(atomic_t){.counter = (int)0,}",
+ {.counter = 0,});
+ TEST_BTF_DUMP_DATA(btf, d, str, atomic_t, BTF_F_NONAME | BTF_F_ZERO,
+ "{0,}", {.counter = 0,});
+ /* enum where enum value does (and does not) exist */
+ TEST_BTF_DUMP_DATA_C(btf, d, str, enum bpf_cmd, 0, BPF_MAP_CREATE);
+ TEST_BTF_DUMP_DATA(btf, d, str, enum bpf_cmd, 0,
+ "(enum bpf_cmd)BPF_MAP_CREATE", 0);
+ TEST_BTF_DUMP_DATA(btf, d, str, enum bpf_cmd, BTF_F_NONAME,
+ "BPF_MAP_CREATE",
+ BPF_MAP_CREATE);
+ TEST_BTF_DUMP_DATA(btf, d, str, enum bpf_cmd,
+ BTF_F_NONAME | BTF_F_ZERO,
+ "BPF_MAP_CREATE", 0);
+
+ TEST_BTF_DUMP_DATA(btf, d, str, enum bpf_cmd, BTF_F_ZERO,
+ "(enum bpf_cmd)BPF_MAP_CREATE",
+ BPF_MAP_CREATE);
+ TEST_BTF_DUMP_DATA(btf, d, str, enum bpf_cmd,
+ BTF_F_NONAME | BTF_F_ZERO,
+ "BPF_MAP_CREATE", BPF_MAP_CREATE);
+ TEST_BTF_DUMP_DATA_C(btf, d, str, enum bpf_cmd, 0, 2000);
+ TEST_BTF_DUMP_DATA(btf, d, str, enum bpf_cmd, BTF_F_NONAME,
+ "2000", 2000);
+
+ /* simple struct */
+ TEST_BTF_DUMP_DATA_C(btf, d, str, struct btf_enum, 0,
+ {.name_off = (__u32)3,.val = (__s32)-1,});
+ TEST_BTF_DUMP_DATA(btf, d, str, struct btf_enum, BTF_F_NONAME,
+ "{3,-1,}",
+ { .name_off = 3, .val = -1,});
+ TEST_BTF_DUMP_DATA(btf, d, str, struct btf_enum, BTF_F_NONAME, "{-1,}",
+ { .name_off = 0, .val = -1,});
+ TEST_BTF_DUMP_DATA(btf, d, str, struct btf_enum,
+ BTF_F_NONAME | BTF_F_ZERO,
+ "{0,-1,}",
+ { .name_off = 0, .val = -1,});
+ /* empty struct should be printed */
+ TEST_BTF_DUMP_DATA(btf, d, str, struct btf_enum, 0,
+ "(struct btf_enum){}",
+ { .name_off = 0, .val = 0,});
+ TEST_BTF_DUMP_DATA(btf, d, str, struct btf_enum, BTF_F_NONAME, "{}",
+ { .name_off = 0, .val = 0,});
+ TEST_BTF_DUMP_DATA(btf, d, str, struct btf_enum, BTF_F_ZERO,
+ "(struct btf_enum){.name_off = (__u32)0,.val = (__s32)0,}",
+ { .name_off = 0, .val = 0,});
+
+ /* struct with pointers */
+ TEST_BTF_DUMP_DATA(btf, d, str, struct list_head, 0,
+ "(struct list_head){.next = (struct list_head *)0x1,}",
+ { .next = (struct list_head *)1 });
+ /* NULL pointer should not be displayed */
+ TEST_BTF_DUMP_DATA(btf, d, str, struct list_head, 0,
+ "(struct list_head){}",
+ { .next = (struct list_head *)0 });
+ /* struct with char array */
+ TEST_BTF_DUMP_DATA(btf, d, str, struct bpf_prog_info, 0,
+ "(struct bpf_prog_info){.name = (char[])['f','o','o',],}",
+ { .name = "foo",});
+ TEST_BTF_DUMP_DATA(btf, d, str, struct bpf_prog_info, BTF_F_NONAME,
+ "{['f','o','o',],}",
+ {.name = "foo",});
+ /* leading null char means do not display string */
+ TEST_BTF_DUMP_DATA(btf, d, str, struct bpf_prog_info, 0,
+ "(struct bpf_prog_info){}",
+ {.name = {'\0', 'f', 'o', 'o'}});
+ /* handle non-printable characters */
+ TEST_BTF_DUMP_DATA(btf, d, str, struct bpf_prog_info, 0,
+ "(struct bpf_prog_info){.name = (char[])[1,2,3,],}",
+ { .name = {1, 2, 3, 0}});
+
+ /* struct with non-char array */
+ TEST_BTF_DUMP_DATA(btf, d, str, struct __sk_buff, 0,
+ "(struct __sk_buff){.cb = (__u32[])[1,2,3,4,5,],}",
+ { .cb = {1, 2, 3, 4, 5,},});
+ TEST_BTF_DUMP_DATA(btf, d, str, struct __sk_buff, BTF_F_NONAME,
+ "{[1,2,3,4,5,],}",
+ { .cb = { 1, 2, 3, 4, 5},});
+ /* For non-char, arrays, show non-zero values only */
+ TEST_BTF_DUMP_DATA(btf, d, str, struct __sk_buff, 0,
+ "(struct __sk_buff){.cb = (__u32[])[1,],}",
+ { .cb = { 0, 0, 1, 0, 0},});
+
+ /* struct with bitfields */
+ TEST_BTF_DUMP_DATA_C(btf, d, str, struct bpf_insn, 0,
+ {.code = (__u8)1,.dst_reg = (__u8)0x2,.src_reg = (__u8)0x3,.off = (__s16)4,.imm = (__s32)5,});
+ TEST_BTF_DUMP_DATA(btf, d, str, struct bpf_insn, BTF_F_NONAME,
+ "{1,0x2,0x3,4,5,}",
+ { .code = 1, .dst_reg = 0x2, .src_reg = 0x3, .off = 4,
+ .imm = 5,});
+}
+
+
void test_btf_dump() {
int i;
@@ -245,4 +476,6 @@ void test_btf_dump() {
}
if (test__start_subtest("btf_dump: incremental"))
test_btf_dump_incremental();
+ if (test__start_subtest("btf_dump: data"))
+ test_btf_dump_data();
}
--
1.8.3.1