1 // SPDX-License-Identifier: GPL-2.0
6 #include <bpf/libbpf.h>
15 #define ptr_to_u64(ptr) ((__u64)(unsigned long)(ptr))
17 static int snprintf_hex(char *buf
, size_t size
, unsigned char *data
, size_t len
)
22 for (i
= 0; i
< len
; i
++)
23 ret
+= snprintf(buf
+ ret
, size
- ret
, "%02x", data
[i
]);
27 int machine__process_bpf_event(struct machine
*machine __maybe_unused
,
28 union perf_event
*event
,
29 struct perf_sample
*sample __maybe_unused
)
32 perf_event__fprintf_bpf_event(event
, stdout
);
37 * Synthesize PERF_RECORD_KSYMBOL and PERF_RECORD_BPF_EVENT for one bpf
38 * program. One PERF_RECORD_BPF_EVENT is generated for the program. And
39 * one PERF_RECORD_KSYMBOL is generated for each sub program.
44 * -2 for lack of kernel support.
46 static int perf_event__synthesize_one_bpf_prog(struct perf_session
*session
,
47 perf_event__handler_t process
,
48 struct machine
*machine
,
50 union perf_event
*event
,
51 struct record_opts
*opts
)
53 struct ksymbol_event
*ksymbol_event
= &event
->ksymbol_event
;
54 struct bpf_event
*bpf_event
= &event
->bpf_event
;
55 struct bpf_prog_info_linear
*info_linear
;
56 struct perf_tool
*tool
= session
->tool
;
57 struct bpf_prog_info
*info
;
58 struct btf
*btf
= NULL
;
64 arrays
= 1UL << BPF_PROG_INFO_JITED_KSYMS
;
65 arrays
|= 1UL << BPF_PROG_INFO_JITED_FUNC_LENS
;
66 arrays
|= 1UL << BPF_PROG_INFO_FUNC_INFO
;
67 arrays
|= 1UL << BPF_PROG_INFO_PROG_TAGS
;
69 info_linear
= bpf_program__get_prog_info_linear(fd
, arrays
);
70 if (IS_ERR_OR_NULL(info_linear
)) {
72 pr_debug("%s: failed to get BPF program info. aborting\n", __func__
);
76 if (info_linear
->info_len
< offsetof(struct bpf_prog_info
, prog_tags
)) {
77 pr_debug("%s: the kernel is too old, aborting\n", __func__
);
81 info
= &info_linear
->info
;
83 /* number of ksyms, func_lengths, and tags should match */
84 sub_prog_cnt
= info
->nr_jited_ksyms
;
85 if (sub_prog_cnt
!= info
->nr_prog_tags
||
86 sub_prog_cnt
!= info
->nr_jited_func_lens
)
89 /* check BTF func info support */
90 if (info
->btf_id
&& info
->nr_func_info
&& info
->func_info_rec_size
) {
91 /* btf func info number should be same as sub_prog_cnt */
92 if (sub_prog_cnt
!= info
->nr_func_info
) {
93 pr_debug("%s: mismatch in BPF sub program count and BTF function info count, aborting\n", __func__
);
97 if (btf__get_from_id(info
->btf_id
, &btf
)) {
98 pr_debug("%s: failed to get BTF of id %u, aborting\n", __func__
, info
->btf_id
);
106 /* Synthesize PERF_RECORD_KSYMBOL */
107 for (i
= 0; i
< sub_prog_cnt
; i
++) {
108 u8 (*prog_tags
)[BPF_TAG_SIZE
] = (void *)(uintptr_t)(info
->prog_tags
);
109 __u32
*prog_lens
= (__u32
*)(uintptr_t)(info
->jited_func_lens
);
110 __u64
*prog_addrs
= (__u64
*)(uintptr_t)(info
->jited_ksyms
);
111 void *func_infos
= (void *)(uintptr_t)(info
->func_info
);
112 const struct bpf_func_info
*finfo
;
113 const char *short_name
= NULL
;
114 const struct btf_type
*t
;
117 *ksymbol_event
= (struct ksymbol_event
){
119 .type
= PERF_RECORD_KSYMBOL
,
120 .size
= offsetof(struct ksymbol_event
, name
),
122 .addr
= prog_addrs
[i
],
124 .ksym_type
= PERF_RECORD_KSYMBOL_TYPE_BPF
,
127 name_len
= snprintf(ksymbol_event
->name
, KSYM_NAME_LEN
,
129 name_len
+= snprintf_hex(ksymbol_event
->name
+ name_len
,
130 KSYM_NAME_LEN
- name_len
,
131 prog_tags
[i
], BPF_TAG_SIZE
);
133 finfo
= func_infos
+ i
* info
->func_info_rec_size
;
134 t
= btf__type_by_id(btf
, finfo
->type_id
);
135 short_name
= btf__name_by_offset(btf
, t
->name_off
);
136 } else if (i
== 0 && sub_prog_cnt
== 1) {
139 short_name
= info
->name
;
143 name_len
+= snprintf(ksymbol_event
->name
+ name_len
,
144 KSYM_NAME_LEN
- name_len
,
147 ksymbol_event
->header
.size
+= PERF_ALIGN(name_len
+ 1,
150 memset((void *)event
+ event
->header
.size
, 0, machine
->id_hdr_size
);
151 event
->header
.size
+= machine
->id_hdr_size
;
152 err
= perf_tool__process_synth_event(tool
, event
,
156 /* Synthesize PERF_RECORD_BPF_EVENT */
157 if (!opts
->no_bpf_event
) {
158 *bpf_event
= (struct bpf_event
){
160 .type
= PERF_RECORD_BPF_EVENT
,
161 .size
= sizeof(struct bpf_event
),
163 .type
= PERF_BPF_EVENT_PROG_LOAD
,
167 memcpy(bpf_event
->tag
, info
->tag
, BPF_TAG_SIZE
);
168 memset((void *)event
+ event
->header
.size
, 0, machine
->id_hdr_size
);
169 event
->header
.size
+= machine
->id_hdr_size
;
170 err
= perf_tool__process_synth_event(tool
, event
,
180 int perf_event__synthesize_bpf_events(struct perf_session
*session
,
181 perf_event__handler_t process
,
182 struct machine
*machine
,
183 struct record_opts
*opts
)
185 union perf_event
*event
;
190 event
= malloc(sizeof(event
->bpf_event
) + KSYM_NAME_LEN
+ machine
->id_hdr_size
);
194 err
= bpf_prog_get_next_id(id
, &id
);
196 if (errno
== ENOENT
) {
200 pr_debug("%s: can't get next program: %s%s\n",
201 __func__
, strerror(errno
),
202 errno
== EINVAL
? " -- kernel too old?" : "");
203 /* don't report error on old kernel or EPERM */
204 err
= (errno
== EINVAL
|| errno
== EPERM
) ? 0 : -1;
207 fd
= bpf_prog_get_fd_by_id(id
);
209 pr_debug("%s: failed to get fd for prog_id %u\n",
214 err
= perf_event__synthesize_one_bpf_prog(session
, process
,
219 /* do not return error for old kernel */