summaryrefslogtreecommitdiffstats
path: root/tools/testing/selftests/bpf/progs/pyperf.h
blob: 0cc5e4ee90bd7d7c5f40170537dd80266452a391 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
// SPDX-License-Identifier: GPL-2.0
// Copyright (c) 2019 Facebook
#include <linux/sched.h>
#include <linux/ptrace.h>
#include <stdint.h>
#include <stddef.h>
#include <stdbool.h>
#include <linux/bpf.h>
#include "bpf_helpers.h"

#define FUNCTION_NAME_LEN 64
#define FILE_NAME_LEN 128
#define TASK_COMM_LEN 16

typedef struct {
	int PyThreadState_frame;
	int PyThreadState_thread;
	int PyFrameObject_back;
	int PyFrameObject_code;
	int PyFrameObject_lineno;
	int PyCodeObject_filename;
	int PyCodeObject_name;
	int String_data;
	int String_size;
} OffsetConfig;

typedef struct {
	uintptr_t current_state_addr;
	uintptr_t tls_key_addr;
	OffsetConfig offsets;
	bool use_tls;
} PidData;

typedef struct {
	uint32_t success;
} Stats;

typedef struct {
	char name[FUNCTION_NAME_LEN];
	char file[FILE_NAME_LEN];
} Symbol;

typedef struct {
	uint32_t pid;
	uint32_t tid;
	char comm[TASK_COMM_LEN];
	int32_t kernel_stack_id;
	int32_t user_stack_id;
	bool thread_current;
	bool pthread_match;
	bool stack_complete;
	int16_t stack_len;
	int32_t stack[STACK_MAX_LEN];

	int has_meta;
	int metadata;
	char dummy_safeguard;
} Event;


struct bpf_elf_map {
	__u32 type;
	__u32 size_key;
	__u32 size_value;
	__u32 max_elem;
	__u32 flags;
};

typedef int pid_t;

typedef struct {
	void* f_back; // PyFrameObject.f_back, previous frame
	void* f_code; // PyFrameObject.f_code, pointer to PyCodeObject
	void* co_filename; // PyCodeObject.co_filename
	void* co_name; // PyCodeObject.co_name
} FrameData;

static inline __attribute__((__always_inline__)) void*
get_thread_state(void* tls_base, PidData* pidData)
{
	void* thread_state;
	int key;

	bpf_probe_read(&key, sizeof(key), (void*)(long)pidData->tls_key_addr);
	bpf_probe_read(&thread_state, sizeof(thread_state),
		       tls_base + 0x310 + key * 0x10 + 0x08);
	return thread_state;
}

static inline __attribute__((__always_inline__)) bool
get_frame_data(void* frame_ptr, PidData* pidData, FrameData* frame, Symbol* symbol)
{
	// read data from PyFrameObject
	bpf_probe_read(&frame->f_back,
		       sizeof(frame->f_back),
		       frame_ptr + pidData->offsets.PyFrameObject_back);
	bpf_probe_read(&frame->f_code,
		       sizeof(frame->f_code),
		       frame_ptr + pidData->offsets.PyFrameObject_code);

	// read data from PyCodeObject
	if (!frame->f_code)
		return false;
	bpf_probe_read(&frame->co_filename,
		       sizeof(frame->co_filename),
		       frame->f_code + pidData->offsets.PyCodeObject_filename);
	bpf_probe_read(&frame->co_name,
		       sizeof(frame->co_name),
		       frame->f_code + pidData->offsets.PyCodeObject_name);
	// read actual names into symbol
	if (frame->co_filename)
		bpf_probe_read_str(&symbol->file,
				   sizeof(symbol->file),
				   frame->co_filename + pidData->offsets.String_data);
	if (frame->co_name)
		bpf_probe_read_str(&symbol->name,
				   sizeof(symbol->name),
				   frame->co_name + pidData->offsets.String_data);
	return true;
}

struct bpf_elf_map SEC("maps") pidmap = {
	.type = BPF_MAP_TYPE_HASH,
	.size_key = sizeof(int),
	.size_value = sizeof(PidData),
	.max_elem = 1,
};

struct bpf_elf_map SEC("maps") eventmap = {
	.type = BPF_MAP_TYPE_HASH,
	.size_key = sizeof(int),
	.size_value = sizeof(Event),
	.max_elem = 1,
};

struct bpf_elf_map SEC("maps") symbolmap = {
	.type = BPF_MAP_TYPE_HASH,
	.size_key = sizeof(Symbol),
	.size_value = sizeof(int),
	.max_elem = 1,
};

struct bpf_elf_map SEC("maps") statsmap = {
	.type = BPF_MAP_TYPE_ARRAY,
	.size_key = sizeof(Stats),
	.size_value = sizeof(int),
	.max_elem = 1,
};

struct bpf_elf_map SEC("maps") perfmap = {
	.type = BPF_MAP_TYPE_PERF_EVENT_ARRAY,
	.size_key = sizeof(int),
	.size_value = sizeof(int),
	.max_elem = 32,
};

struct bpf_elf_map SEC("maps") stackmap = {
	.type = BPF_MAP_TYPE_STACK_TRACE,
	.size_key = sizeof(int),
	.size_value = sizeof(long long) * 127,
	.max_elem = 1000,
};

static inline __attribute__((__always_inline__)) int __on_event(struct pt_regs *ctx)
{
	uint64_t pid_tgid = bpf_get_current_pid_tgid();
	pid_t pid = (pid_t)(pid_tgid >> 32);
	PidData* pidData = bpf_map_lookup_elem(&pidmap, &pid);
	if (!pidData)
		return 0;

	int zero = 0;
	Event* event = bpf_map_lookup_elem(&eventmap, &zero);
	if (!event)
		return 0;

	event->pid = pid;

	event->tid = (pid_t)pid_tgid;
	bpf_get_current_comm(&event->comm, sizeof(event->comm));

	event->user_stack_id = bpf_get_stackid(ctx, &stackmap, BPF_F_USER_STACK);
	event->kernel_stack_id = bpf_get_stackid(ctx, &stackmap, 0);

	void* thread_state_current = (void*)0;
	bpf_probe_read(&thread_state_current,
		       sizeof(thread_state_current),
		       (void*)(long)pidData->current_state_addr);

	struct task_struct* task = (struct task_struct*)bpf_get_current_task();
	void* tls_base = (void*)task;

	void* thread_state = pidData->use_tls ? get_thread_state(tls_base, pidData)
		: thread_state_current;
	event->thread_current = thread_state == thread_state_current;

	if (pidData->use_tls) {
		uint64_t pthread_created;
		uint64_t pthread_self;
		bpf_probe_read(&pthread_self, sizeof(pthread_self), tls_base + 0x10);

		bpf_probe_read(&pthread_created,
			       sizeof(pthread_created),
			       thread_state + pidData->offsets.PyThreadState_thread);
		event->pthread_match = pthread_created == pthread_self;
	} else {
		event->pthread_match = 1;
	}

	if (event->pthread_match || !pidData->use_tls) {
		void* frame_ptr;
		FrameData frame;
		Symbol sym = {};
		int cur_cpu = bpf_get_smp_processor_id();

		bpf_probe_read(&frame_ptr,
			       sizeof(frame_ptr),
			       thread_state + pidData->offsets.PyThreadState_frame);

		int32_t* symbol_counter = bpf_map_lookup_elem(&symbolmap, &sym);
		if (symbol_counter == NULL)
			return 0;
#pragma unroll
		/* Unwind python stack */
		for (int i = 0; i < STACK_MAX_LEN; ++i) {
			if (frame_ptr && get_frame_data(frame_ptr, pidData, &frame, &sym)) {
				int32_t new_symbol_id = *symbol_counter * 64 + cur_cpu;
				int32_t *symbol_id = bpf_map_lookup_elem(&symbolmap, &sym);
				if (!symbol_id) {
					bpf_map_update_elem(&symbolmap, &sym, &zero, 0);
					symbol_id = bpf_map_lookup_elem(&symbolmap, &sym);
					if (!symbol_id)
						return 0;
				}
				if (*symbol_id == new_symbol_id)
					(*symbol_counter)++;
				event->stack[i] = *symbol_id;
				event->stack_len = i + 1;
				frame_ptr = frame.f_back;
			}
		}
		event->stack_complete = frame_ptr == NULL;
	} else {
		event->stack_complete = 1;
	}

	Stats* stats = bpf_map_lookup_elem(&statsmap, &zero);
	if (stats)
		stats->success++;

	event->has_meta = 0;
	bpf_perf_event_output(ctx, &perfmap, 0, event, offsetof(Event, metadata));
	return 0;
}

SEC("raw_tracepoint/kfree_skb")
int on_event(struct pt_regs* ctx)
{
	int i, ret = 0;
	ret |= __on_event(ctx);
	ret |= __on_event(ctx);
	ret |= __on_event(ctx);
	ret |= __on_event(ctx);
	ret |= __on_event(ctx);
	return ret;
}

char _license[] SEC("license") = "GPL";