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// SPDX-License-Identifier: GPL-2.0
/* Copyright (c) 2020, Oracle and/or its affiliates. */
#include "btf_ptr.h"
#include <bpf/bpf_helpers.h>
#include <bpf/bpf_tracing.h>
#include <bpf/bpf_core_read.h>
#include <errno.h>
long ret = 0;
int num_subtests = 0;
int ran_subtests = 0;
bool skip = false;
#define STRSIZE 2048
#define EXPECTED_STRSIZE 256
#if defined(bpf_target_s390)
/* NULL points to a readable struct lowcore on s390, so take the last page */
#define BADPTR ((void *)0xFFFFFFFFFFFFF000ULL)
#else
#define BADPTR 0
#endif
#ifndef ARRAY_SIZE
#define ARRAY_SIZE(x) (sizeof(x) / sizeof((x)[0]))
#endif
struct {
__uint(type, BPF_MAP_TYPE_PERCPU_ARRAY);
__uint(max_entries, 1);
__type(key, __u32);
__type(value, char[STRSIZE]);
} strdata SEC(".maps");
static int __strncmp(const void *m1, const void *m2, size_t len)
{
const unsigned char *s1 = m1;
const unsigned char *s2 = m2;
int i, delta = 0;
for (i = 0; i < len; i++) {
delta = s1[i] - s2[i];
if (delta || s1[i] == 0 || s2[i] == 0)
break;
}
return delta;
}
#if __has_builtin(__builtin_btf_type_id)
#define TEST_BTF(_str, _type, _flags, _expected, ...) \
do { \
static const char _expectedval[EXPECTED_STRSIZE] = \
_expected; \
static const char _ptrtype[64] = #_type; \
__u64 _hflags = _flags | BTF_F_COMPACT; \
static _type _ptrdata = __VA_ARGS__; \
static struct btf_ptr _ptr = { }; \
int _cmp; \
\
++num_subtests; \
if (ret < 0) \
break; \
++ran_subtests; \
_ptr.ptr = &_ptrdata; \
_ptr.type_id = bpf_core_type_id_kernel(_type); \
if (_ptr.type_id <= 0) { \
ret = -EINVAL; \
break; \
} \
ret = bpf_snprintf_btf(_str, STRSIZE, \
&_ptr, sizeof(_ptr), _hflags); \
if (ret) \
break; \
_cmp = __strncmp(_str, _expectedval, EXPECTED_STRSIZE); \
if (_cmp != 0) { \
bpf_printk("(%d) got %s", _cmp, _str); \
bpf_printk("(%d) expected %s", _cmp, \
_expectedval); \
ret = -EBADMSG; \
break; \
} \
} while (0)
#endif
/* Use where expected data string matches its stringified declaration */
#define TEST_BTF_C(_str, _type, _flags, ...) \
TEST_BTF(_str, _type, _flags, "(" #_type ")" #__VA_ARGS__, \
__VA_ARGS__)
/* TRACE_EVENT(netif_receive_skb,
* TP_PROTO(struct sk_buff *skb),
*/
SEC("tp_btf/netif_receive_skb")
int BPF_PROG(trace_netif_receive_skb, struct sk_buff *skb)
{
static __u64 flags[] = { 0, BTF_F_COMPACT, BTF_F_ZERO, BTF_F_PTR_RAW,
BTF_F_NONAME, BTF_F_COMPACT | BTF_F_ZERO |
BTF_F_PTR_RAW | BTF_F_NONAME };
static struct btf_ptr p = { };
__u32 key = 0;
int i, __ret;
char *str;
#if __has_builtin(__builtin_btf_type_id)
str = bpf_map_lookup_elem(&strdata, &key);
if (!str)
return 0;
/* Ensure we can write skb string representation */
p.type_id = bpf_core_type_id_kernel(struct sk_buff);
p.ptr = skb;
for (i = 0; i < ARRAY_SIZE(flags); i++) {
++num_subtests;
ret = bpf_snprintf_btf(str, STRSIZE, &p, sizeof(p), 0);
if (ret < 0)
bpf_printk("returned %d when writing skb", ret);
++ran_subtests;
}
/* Check invalid ptr value */
p.ptr = BADPTR;
__ret = bpf_snprintf_btf(str, STRSIZE, &p, sizeof(p), 0);
if (__ret >= 0) {
bpf_printk("printing %llx should generate error, got (%d)",
(unsigned long long)BADPTR, __ret);
ret = -ERANGE;
}
/* Verify type display for various types. */
/* simple int */
TEST_BTF_C(str, int, 0, 1234);
TEST_BTF(str, int, BTF_F_NONAME, "1234", 1234);
/* zero value should be printed at toplevel */
TEST_BTF(str, int, 0, "(int)0", 0);
TEST_BTF(str, int, BTF_F_NONAME, "0", 0);
TEST_BTF(str, int, BTF_F_ZERO, "(int)0", 0);
TEST_BTF(str, int, BTF_F_NONAME | BTF_F_ZERO, "0", 0);
TEST_BTF_C(str, int, 0, -4567);
TEST_BTF(str, int, BTF_F_NONAME, "-4567", -4567);
/* simple char */
TEST_BTF_C(str, char, 0, 100);
TEST_BTF(str, char, BTF_F_NONAME, "100", 100);
/* zero value should be printed at toplevel */
TEST_BTF(str, char, 0, "(char)0", 0);
TEST_BTF(str, char, BTF_F_NONAME, "0", 0);
TEST_BTF(str, char, BTF_F_ZERO, "(char)0", 0);
TEST_BTF(str, char, BTF_F_NONAME | BTF_F_ZERO, "0", 0);
/* simple typedef */
TEST_BTF_C(str, uint64_t, 0, 100);
TEST_BTF(str, u64, BTF_F_NONAME, "1", 1);
/* zero value should be printed at toplevel */
TEST_BTF(str, u64, 0, "(u64)0", 0);
TEST_BTF(str, u64, BTF_F_NONAME, "0", 0);
TEST_BTF(str, u64, BTF_F_ZERO, "(u64)0", 0);
TEST_BTF(str, u64, BTF_F_NONAME|BTF_F_ZERO, "0", 0);
/* typedef struct */
TEST_BTF_C(str, atomic_t, 0, {.counter = (int)1,});
TEST_BTF(str, atomic_t, BTF_F_NONAME, "{1,}", {.counter = 1,});
/* typedef with 0 value should be printed at toplevel */
TEST_BTF(str, atomic_t, 0, "(atomic_t){}", {.counter = 0,});
TEST_BTF(str, atomic_t, BTF_F_NONAME, "{}", {.counter = 0,});
TEST_BTF(str, atomic_t, BTF_F_ZERO, "(atomic_t){.counter = (int)0,}",
{.counter = 0,});
TEST_BTF(str, atomic_t, BTF_F_NONAME|BTF_F_ZERO,
"{0,}", {.counter = 0,});
/* enum where enum value does (and does not) exist */
TEST_BTF_C(str, enum bpf_cmd, 0, BPF_MAP_CREATE);
TEST_BTF(str, enum bpf_cmd, 0, "(enum bpf_cmd)BPF_MAP_CREATE", 0);
TEST_BTF(str, enum bpf_cmd, BTF_F_NONAME, "BPF_MAP_CREATE",
BPF_MAP_CREATE);
TEST_BTF(str, enum bpf_cmd, BTF_F_NONAME|BTF_F_ZERO,
"BPF_MAP_CREATE", 0);
TEST_BTF(str, enum bpf_cmd, BTF_F_ZERO, "(enum bpf_cmd)BPF_MAP_CREATE",
BPF_MAP_CREATE);
TEST_BTF(str, enum bpf_cmd, BTF_F_NONAME|BTF_F_ZERO,
"BPF_MAP_CREATE", BPF_MAP_CREATE);
TEST_BTF_C(str, enum bpf_cmd, 0, 2000);
TEST_BTF(str, enum bpf_cmd, BTF_F_NONAME, "2000", 2000);
/* simple struct */
TEST_BTF_C(str, struct btf_enum, 0,
{.name_off = (__u32)3,.val = (__s32)-1,});
TEST_BTF(str, struct btf_enum, BTF_F_NONAME, "{3,-1,}",
{ .name_off = 3, .val = -1,});
TEST_BTF(str, struct btf_enum, BTF_F_NONAME, "{-1,}",
{ .name_off = 0, .val = -1,});
TEST_BTF(str, struct btf_enum, BTF_F_NONAME|BTF_F_ZERO, "{0,-1,}",
{ .name_off = 0, .val = -1,});
/* empty struct should be printed */
TEST_BTF(str, struct btf_enum, 0, "(struct btf_enum){}",
{ .name_off = 0, .val = 0,});
TEST_BTF(str, struct btf_enum, BTF_F_NONAME, "{}",
{ .name_off = 0, .val = 0,});
TEST_BTF(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(str, struct list_head, BTF_F_PTR_RAW,
"(struct list_head){.next = (struct list_head *)0x0000000000000001,}",
{ .next = (struct list_head *)1 });
/* NULL pointer should not be displayed */
TEST_BTF(str, struct list_head, BTF_F_PTR_RAW,
"(struct list_head){}",
{ .next = (struct list_head *)0 });
/* struct with char array */
TEST_BTF(str, struct bpf_prog_info, 0,
"(struct bpf_prog_info){.name = (char[])['f','o','o',],}",
{ .name = "foo",});
TEST_BTF(str, struct bpf_prog_info, BTF_F_NONAME,
"{['f','o','o',],}",
{.name = "foo",});
/* leading null char means do not display string */
TEST_BTF(str, struct bpf_prog_info, 0,
"(struct bpf_prog_info){}",
{.name = {'\0', 'f', 'o', 'o'}});
/* handle non-printable characters */
TEST_BTF(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(str, struct __sk_buff, 0,
"(struct __sk_buff){.cb = (__u32[])[1,2,3,4,5,],}",
{ .cb = {1, 2, 3, 4, 5,},});
TEST_BTF(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(str, struct __sk_buff, 0,
"(struct __sk_buff){.cb = (__u32[])[1,],}",
{ .cb = { 0, 0, 1, 0, 0},});
/* struct with bitfields */
TEST_BTF_C(str, struct bpf_insn, 0,
{.code = (__u8)1,.dst_reg = (__u8)0x2,.src_reg = (__u8)0x3,.off = (__s16)4,.imm = (__s32)5,});
TEST_BTF(str, struct bpf_insn, BTF_F_NONAME, "{1,0x2,0x3,4,5,}",
{.code = 1, .dst_reg = 0x2, .src_reg = 0x3, .off = 4,
.imm = 5,});
#else
skip = true;
#endif
return 0;
}
char _license[] SEC("license") = "GPL";
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