1 // SPDX-License-Identifier: GPL-2.0
2 /* Copyright (c) 2020 Facebook */
3 #include <vmlinux.h>
4 #include <bpf/bpf_core_read.h>
5 #include <bpf/bpf_helpers.h>
6 #include <bpf/bpf_tracing.h>
7
8 #include "profiler.h"
9
10 #ifndef NULL
11 #define NULL 0
12 #endif
13
14 #define O_WRONLY 00000001
15 #define O_RDWR 00000002
16 #define O_DIRECTORY 00200000
17 #define __O_TMPFILE 020000000
18 #define O_TMPFILE (__O_TMPFILE | O_DIRECTORY)
19 #define MAX_ERRNO 4095
20 #define S_IFMT 00170000
21 #define S_IFSOCK 0140000
22 #define S_IFLNK 0120000
23 #define S_IFREG 0100000
24 #define S_IFBLK 0060000
25 #define S_IFDIR 0040000
26 #define S_IFCHR 0020000
27 #define S_IFIFO 0010000
28 #define S_ISUID 0004000
29 #define S_ISGID 0002000
30 #define S_ISVTX 0001000
31 #define S_ISLNK(m) (((m)&S_IFMT) == S_IFLNK)
32 #define S_ISDIR(m) (((m)&S_IFMT) == S_IFDIR)
33 #define S_ISCHR(m) (((m)&S_IFMT) == S_IFCHR)
34 #define S_ISBLK(m) (((m)&S_IFMT) == S_IFBLK)
35 #define S_ISFIFO(m) (((m)&S_IFMT) == S_IFIFO)
36 #define S_ISSOCK(m) (((m)&S_IFMT) == S_IFSOCK)
37 #define IS_ERR_VALUE(x) (unsigned long)(void*)(x) >= (unsigned long)-MAX_ERRNO
38
39 #define KILL_DATA_ARRAY_SIZE 8
40
41 struct var_kill_data_arr_t {
42 struct var_kill_data_t array[KILL_DATA_ARRAY_SIZE];
43 };
44
45 union any_profiler_data_t {
46 struct var_exec_data_t var_exec;
47 struct var_kill_data_t var_kill;
48 struct var_sysctl_data_t var_sysctl;
49 struct var_filemod_data_t var_filemod;
50 struct var_fork_data_t var_fork;
51 struct var_kill_data_arr_t var_kill_data_arr;
52 };
53
54 volatile struct profiler_config_struct bpf_config = {};
55
56 #define FETCH_CGROUPS_FROM_BPF (bpf_config.fetch_cgroups_from_bpf)
57 #define CGROUP_FS_INODE (bpf_config.cgroup_fs_inode)
58 #define CGROUP_LOGIN_SESSION_INODE \
59 (bpf_config.cgroup_login_session_inode)
60 #define KILL_SIGNALS (bpf_config.kill_signals_mask)
61 #define STALE_INFO (bpf_config.stale_info_secs)
62 #define INODE_FILTER (bpf_config.inode_filter)
63 #define READ_ENVIRON_FROM_EXEC (bpf_config.read_environ_from_exec)
64 #define ENABLE_CGROUP_V1_RESOLVER (bpf_config.enable_cgroup_v1_resolver)
65
66 struct kernfs_iattrs___52 {
67 struct iattr ia_iattr;
68 };
69
70 struct kernfs_node___52 {
71 union /* kernfs_node_id */ {
72 struct {
73 u32 ino;
74 u32 generation;
75 };
76 u64 id;
77 } id;
78 };
79
80 struct {
81 __uint(type, BPF_MAP_TYPE_PERCPU_ARRAY);
82 __uint(max_entries, 1);
83 __type(key, u32);
84 __type(value, union any_profiler_data_t);
85 } data_heap SEC(".maps");
86
87 struct {
88 __uint(type, BPF_MAP_TYPE_PERF_EVENT_ARRAY);
89 __uint(key_size, sizeof(int));
90 __uint(value_size, sizeof(int));
91 } events SEC(".maps");
92
93 struct {
94 __uint(type, BPF_MAP_TYPE_HASH);
95 __uint(max_entries, KILL_DATA_ARRAY_SIZE);
96 __type(key, u32);
97 __type(value, struct var_kill_data_arr_t);
98 } var_tpid_to_data SEC(".maps");
99
100 struct {
101 __uint(type, BPF_MAP_TYPE_PERCPU_ARRAY);
102 __uint(max_entries, profiler_bpf_max_function_id);
103 __type(key, u32);
104 __type(value, struct bpf_func_stats_data);
105 } bpf_func_stats SEC(".maps");
106
107 struct {
108 __uint(type, BPF_MAP_TYPE_HASH);
109 __type(key, u32);
110 __type(value, bool);
111 __uint(max_entries, 16);
112 } allowed_devices SEC(".maps");
113
114 struct {
115 __uint(type, BPF_MAP_TYPE_HASH);
116 __type(key, u64);
117 __type(value, bool);
118 __uint(max_entries, 1024);
119 } allowed_file_inodes SEC(".maps");
120
121 struct {
122 __uint(type, BPF_MAP_TYPE_HASH);
123 __type(key, u64);
124 __type(value, bool);
125 __uint(max_entries, 1024);
126 } allowed_directory_inodes SEC(".maps");
127
128 struct {
129 __uint(type, BPF_MAP_TYPE_HASH);
130 __type(key, u32);
131 __type(value, bool);
132 __uint(max_entries, 16);
133 } disallowed_exec_inodes SEC(".maps");
134
135 #ifndef ARRAY_SIZE
136 #define ARRAY_SIZE(arr) (sizeof(arr) / sizeof(arr[0]))
137 #endif
138
IS_ERR(const void * ptr)139 static INLINE bool IS_ERR(const void* ptr)
140 {
141 return IS_ERR_VALUE((unsigned long)ptr);
142 }
143
get_userspace_pid()144 static INLINE u32 get_userspace_pid()
145 {
146 return bpf_get_current_pid_tgid() >> 32;
147 }
148
is_init_process(u32 tgid)149 static INLINE bool is_init_process(u32 tgid)
150 {
151 return tgid == 1 || tgid == 0;
152 }
153
154 static INLINE unsigned long
probe_read_lim(void * dst,void * src,unsigned long len,unsigned long max)155 probe_read_lim(void* dst, void* src, unsigned long len, unsigned long max)
156 {
157 len = len < max ? len : max;
158 if (len > 1) {
159 if (bpf_probe_read(dst, len, src))
160 return 0;
161 } else if (len == 1) {
162 if (bpf_probe_read(dst, 1, src))
163 return 0;
164 }
165 return len;
166 }
167
get_var_spid_index(struct var_kill_data_arr_t * arr_struct,int spid)168 static INLINE int get_var_spid_index(struct var_kill_data_arr_t* arr_struct,
169 int spid)
170 {
171 #ifdef UNROLL
172 #pragma unroll
173 #endif
174 for (int i = 0; i < ARRAY_SIZE(arr_struct->array); i++)
175 if (arr_struct->array[i].meta.pid == spid)
176 return i;
177 return -1;
178 }
179
populate_ancestors(struct task_struct * task,struct ancestors_data_t * ancestors_data)180 static INLINE void populate_ancestors(struct task_struct* task,
181 struct ancestors_data_t* ancestors_data)
182 {
183 struct task_struct* parent = task;
184 u32 num_ancestors, ppid;
185
186 ancestors_data->num_ancestors = 0;
187 #ifdef UNROLL
188 #pragma unroll
189 #endif
190 for (num_ancestors = 0; num_ancestors < MAX_ANCESTORS; num_ancestors++) {
191 parent = BPF_CORE_READ(parent, real_parent);
192 if (parent == NULL)
193 break;
194 ppid = BPF_CORE_READ(parent, tgid);
195 if (is_init_process(ppid))
196 break;
197 ancestors_data->ancestor_pids[num_ancestors] = ppid;
198 ancestors_data->ancestor_exec_ids[num_ancestors] =
199 BPF_CORE_READ(parent, self_exec_id);
200 ancestors_data->ancestor_start_times[num_ancestors] =
201 BPF_CORE_READ(parent, start_time);
202 ancestors_data->num_ancestors = num_ancestors;
203 }
204 }
205
read_full_cgroup_path(struct kernfs_node * cgroup_node,struct kernfs_node * cgroup_root_node,void * payload,int * root_pos)206 static INLINE void* read_full_cgroup_path(struct kernfs_node* cgroup_node,
207 struct kernfs_node* cgroup_root_node,
208 void* payload,
209 int* root_pos)
210 {
211 void* payload_start = payload;
212 size_t filepart_length;
213
214 #ifdef UNROLL
215 #pragma unroll
216 #endif
217 for (int i = 0; i < MAX_CGROUPS_PATH_DEPTH; i++) {
218 filepart_length =
219 bpf_probe_read_str(payload, MAX_PATH, BPF_CORE_READ(cgroup_node, name));
220 if (!cgroup_node)
221 return payload;
222 if (cgroup_node == cgroup_root_node)
223 *root_pos = payload - payload_start;
224 if (filepart_length <= MAX_PATH) {
225 barrier_var(filepart_length);
226 payload += filepart_length;
227 }
228 cgroup_node = BPF_CORE_READ(cgroup_node, parent);
229 }
230 return payload;
231 }
232
get_inode_from_kernfs(struct kernfs_node * node)233 static ino_t get_inode_from_kernfs(struct kernfs_node* node)
234 {
235 struct kernfs_node___52* node52 = (void*)node;
236
237 if (bpf_core_field_exists(node52->id.ino)) {
238 barrier_var(node52);
239 return BPF_CORE_READ(node52, id.ino);
240 } else {
241 barrier_var(node);
242 return (u64)BPF_CORE_READ(node, id);
243 }
244 }
245
246 extern bool CONFIG_CGROUP_PIDS __kconfig __weak;
247 enum cgroup_subsys_id___local {
248 pids_cgrp_id___local = 123, /* value doesn't matter */
249 };
250
populate_cgroup_info(struct cgroup_data_t * cgroup_data,struct task_struct * task,void * payload)251 static INLINE void* populate_cgroup_info(struct cgroup_data_t* cgroup_data,
252 struct task_struct* task,
253 void* payload)
254 {
255 struct kernfs_node* root_kernfs =
256 BPF_CORE_READ(task, nsproxy, cgroup_ns, root_cset, dfl_cgrp, kn);
257 struct kernfs_node* proc_kernfs = BPF_CORE_READ(task, cgroups, dfl_cgrp, kn);
258
259 #if __has_builtin(__builtin_preserve_enum_value)
260 if (ENABLE_CGROUP_V1_RESOLVER && CONFIG_CGROUP_PIDS) {
261 int cgrp_id = bpf_core_enum_value(enum cgroup_subsys_id___local,
262 pids_cgrp_id___local);
263 #ifdef UNROLL
264 #pragma unroll
265 #endif
266 for (int i = 0; i < CGROUP_SUBSYS_COUNT; i++) {
267 struct cgroup_subsys_state* subsys =
268 BPF_CORE_READ(task, cgroups, subsys[i]);
269 if (subsys != NULL) {
270 int subsys_id = BPF_CORE_READ(subsys, ss, id);
271 if (subsys_id == cgrp_id) {
272 proc_kernfs = BPF_CORE_READ(subsys, cgroup, kn);
273 root_kernfs = BPF_CORE_READ(subsys, ss, root, kf_root, kn);
274 break;
275 }
276 }
277 }
278 }
279 #endif
280
281 cgroup_data->cgroup_root_inode = get_inode_from_kernfs(root_kernfs);
282 cgroup_data->cgroup_proc_inode = get_inode_from_kernfs(proc_kernfs);
283
284 if (bpf_core_field_exists(root_kernfs->iattr->ia_mtime)) {
285 cgroup_data->cgroup_root_mtime =
286 BPF_CORE_READ(root_kernfs, iattr, ia_mtime.tv_nsec);
287 cgroup_data->cgroup_proc_mtime =
288 BPF_CORE_READ(proc_kernfs, iattr, ia_mtime.tv_nsec);
289 } else {
290 struct kernfs_iattrs___52* root_iattr =
291 (struct kernfs_iattrs___52*)BPF_CORE_READ(root_kernfs, iattr);
292 cgroup_data->cgroup_root_mtime =
293 BPF_CORE_READ(root_iattr, ia_iattr.ia_mtime.tv_nsec);
294
295 struct kernfs_iattrs___52* proc_iattr =
296 (struct kernfs_iattrs___52*)BPF_CORE_READ(proc_kernfs, iattr);
297 cgroup_data->cgroup_proc_mtime =
298 BPF_CORE_READ(proc_iattr, ia_iattr.ia_mtime.tv_nsec);
299 }
300
301 cgroup_data->cgroup_root_length = 0;
302 cgroup_data->cgroup_proc_length = 0;
303 cgroup_data->cgroup_full_length = 0;
304
305 size_t cgroup_root_length =
306 bpf_probe_read_str(payload, MAX_PATH, BPF_CORE_READ(root_kernfs, name));
307 barrier_var(cgroup_root_length);
308 if (cgroup_root_length <= MAX_PATH) {
309 barrier_var(cgroup_root_length);
310 cgroup_data->cgroup_root_length = cgroup_root_length;
311 payload += cgroup_root_length;
312 }
313
314 size_t cgroup_proc_length =
315 bpf_probe_read_str(payload, MAX_PATH, BPF_CORE_READ(proc_kernfs, name));
316 barrier_var(cgroup_proc_length);
317 if (cgroup_proc_length <= MAX_PATH) {
318 barrier_var(cgroup_proc_length);
319 cgroup_data->cgroup_proc_length = cgroup_proc_length;
320 payload += cgroup_proc_length;
321 }
322
323 if (FETCH_CGROUPS_FROM_BPF) {
324 cgroup_data->cgroup_full_path_root_pos = -1;
325 void* payload_end_pos = read_full_cgroup_path(proc_kernfs, root_kernfs, payload,
326 &cgroup_data->cgroup_full_path_root_pos);
327 cgroup_data->cgroup_full_length = payload_end_pos - payload;
328 payload = payload_end_pos;
329 }
330
331 return (void*)payload;
332 }
333
populate_var_metadata(struct var_metadata_t * metadata,struct task_struct * task,u32 pid,void * payload)334 static INLINE void* populate_var_metadata(struct var_metadata_t* metadata,
335 struct task_struct* task,
336 u32 pid, void* payload)
337 {
338 u64 uid_gid = bpf_get_current_uid_gid();
339
340 metadata->uid = (u32)uid_gid;
341 metadata->gid = uid_gid >> 32;
342 metadata->pid = pid;
343 metadata->exec_id = BPF_CORE_READ(task, self_exec_id);
344 metadata->start_time = BPF_CORE_READ(task, start_time);
345 metadata->comm_length = 0;
346
347 size_t comm_length = bpf_core_read_str(payload, TASK_COMM_LEN, &task->comm);
348 barrier_var(comm_length);
349 if (comm_length <= TASK_COMM_LEN) {
350 barrier_var(comm_length);
351 metadata->comm_length = comm_length;
352 payload += comm_length;
353 }
354
355 return (void*)payload;
356 }
357
358 static INLINE struct var_kill_data_t*
get_var_kill_data(struct pt_regs * ctx,int spid,int tpid,int sig)359 get_var_kill_data(struct pt_regs* ctx, int spid, int tpid, int sig)
360 {
361 int zero = 0;
362 struct var_kill_data_t* kill_data = bpf_map_lookup_elem(&data_heap, &zero);
363
364 if (kill_data == NULL)
365 return NULL;
366 struct task_struct* task = (struct task_struct*)bpf_get_current_task();
367
368 void* payload = populate_var_metadata(&kill_data->meta, task, spid, kill_data->payload);
369 payload = populate_cgroup_info(&kill_data->cgroup_data, task, payload);
370 size_t payload_length = payload - (void*)kill_data->payload;
371 kill_data->payload_length = payload_length;
372 populate_ancestors(task, &kill_data->ancestors_info);
373 kill_data->meta.type = KILL_EVENT;
374 kill_data->kill_target_pid = tpid;
375 kill_data->kill_sig = sig;
376 kill_data->kill_count = 1;
377 kill_data->last_kill_time = bpf_ktime_get_ns();
378 return kill_data;
379 }
380
trace_var_sys_kill(void * ctx,int tpid,int sig)381 static INLINE int trace_var_sys_kill(void* ctx, int tpid, int sig)
382 {
383 if ((KILL_SIGNALS & (1ULL << sig)) == 0)
384 return 0;
385
386 u32 spid = get_userspace_pid();
387 struct var_kill_data_arr_t* arr_struct = bpf_map_lookup_elem(&var_tpid_to_data, &tpid);
388
389 if (arr_struct == NULL) {
390 struct var_kill_data_t* kill_data = get_var_kill_data(ctx, spid, tpid, sig);
391 int zero = 0;
392
393 if (kill_data == NULL)
394 return 0;
395 arr_struct = bpf_map_lookup_elem(&data_heap, &zero);
396 if (arr_struct == NULL)
397 return 0;
398 bpf_probe_read(&arr_struct->array[0], sizeof(arr_struct->array[0]), kill_data);
399 } else {
400 int index = get_var_spid_index(arr_struct, spid);
401
402 if (index == -1) {
403 struct var_kill_data_t* kill_data =
404 get_var_kill_data(ctx, spid, tpid, sig);
405 if (kill_data == NULL)
406 return 0;
407 #ifdef UNROLL
408 #pragma unroll
409 #endif
410 for (int i = 0; i < ARRAY_SIZE(arr_struct->array); i++)
411 if (arr_struct->array[i].meta.pid == 0) {
412 bpf_probe_read(&arr_struct->array[i],
413 sizeof(arr_struct->array[i]), kill_data);
414 bpf_map_update_elem(&var_tpid_to_data, &tpid,
415 arr_struct, 0);
416
417 return 0;
418 }
419 return 0;
420 }
421
422 struct var_kill_data_t* kill_data = &arr_struct->array[index];
423
424 u64 delta_sec =
425 (bpf_ktime_get_ns() - kill_data->last_kill_time) / 1000000000;
426
427 if (delta_sec < STALE_INFO) {
428 kill_data->kill_count++;
429 kill_data->last_kill_time = bpf_ktime_get_ns();
430 bpf_probe_read(&arr_struct->array[index],
431 sizeof(arr_struct->array[index]),
432 kill_data);
433 } else {
434 struct var_kill_data_t* kill_data =
435 get_var_kill_data(ctx, spid, tpid, sig);
436 if (kill_data == NULL)
437 return 0;
438 bpf_probe_read(&arr_struct->array[index],
439 sizeof(arr_struct->array[index]),
440 kill_data);
441 }
442 }
443 bpf_map_update_elem(&var_tpid_to_data, &tpid, arr_struct, 0);
444 return 0;
445 }
446
bpf_stats_enter(struct bpf_func_stats_ctx * bpf_stat_ctx,enum bpf_function_id func_id)447 static INLINE void bpf_stats_enter(struct bpf_func_stats_ctx* bpf_stat_ctx,
448 enum bpf_function_id func_id)
449 {
450 int func_id_key = func_id;
451
452 bpf_stat_ctx->start_time_ns = bpf_ktime_get_ns();
453 bpf_stat_ctx->bpf_func_stats_data_val =
454 bpf_map_lookup_elem(&bpf_func_stats, &func_id_key);
455 if (bpf_stat_ctx->bpf_func_stats_data_val)
456 bpf_stat_ctx->bpf_func_stats_data_val->num_executions++;
457 }
458
bpf_stats_exit(struct bpf_func_stats_ctx * bpf_stat_ctx)459 static INLINE void bpf_stats_exit(struct bpf_func_stats_ctx* bpf_stat_ctx)
460 {
461 if (bpf_stat_ctx->bpf_func_stats_data_val)
462 bpf_stat_ctx->bpf_func_stats_data_val->time_elapsed_ns +=
463 bpf_ktime_get_ns() - bpf_stat_ctx->start_time_ns;
464 }
465
466 static INLINE void
bpf_stats_pre_submit_var_perf_event(struct bpf_func_stats_ctx * bpf_stat_ctx,struct var_metadata_t * meta)467 bpf_stats_pre_submit_var_perf_event(struct bpf_func_stats_ctx* bpf_stat_ctx,
468 struct var_metadata_t* meta)
469 {
470 if (bpf_stat_ctx->bpf_func_stats_data_val) {
471 bpf_stat_ctx->bpf_func_stats_data_val->num_perf_events++;
472 meta->bpf_stats_num_perf_events =
473 bpf_stat_ctx->bpf_func_stats_data_val->num_perf_events;
474 }
475 meta->bpf_stats_start_ktime_ns = bpf_stat_ctx->start_time_ns;
476 meta->cpu_id = bpf_get_smp_processor_id();
477 }
478
479 static INLINE size_t
read_absolute_file_path_from_dentry(struct dentry * filp_dentry,void * payload)480 read_absolute_file_path_from_dentry(struct dentry* filp_dentry, void* payload)
481 {
482 size_t length = 0;
483 size_t filepart_length;
484 struct dentry* parent_dentry;
485
486 #ifdef UNROLL
487 #pragma unroll
488 #endif
489 for (int i = 0; i < MAX_PATH_DEPTH; i++) {
490 filepart_length = bpf_probe_read_str(payload, MAX_PATH,
491 BPF_CORE_READ(filp_dentry, d_name.name));
492 barrier_var(filepart_length);
493 if (filepart_length > MAX_PATH)
494 break;
495 barrier_var(filepart_length);
496 payload += filepart_length;
497 length += filepart_length;
498
499 parent_dentry = BPF_CORE_READ(filp_dentry, d_parent);
500 if (filp_dentry == parent_dentry)
501 break;
502 filp_dentry = parent_dentry;
503 }
504
505 return length;
506 }
507
508 static INLINE bool
is_ancestor_in_allowed_inodes(struct dentry * filp_dentry)509 is_ancestor_in_allowed_inodes(struct dentry* filp_dentry)
510 {
511 struct dentry* parent_dentry;
512 #ifdef UNROLL
513 #pragma unroll
514 #endif
515 for (int i = 0; i < MAX_PATH_DEPTH; i++) {
516 u64 dir_ino = BPF_CORE_READ(filp_dentry, d_inode, i_ino);
517 bool* allowed_dir = bpf_map_lookup_elem(&allowed_directory_inodes, &dir_ino);
518
519 if (allowed_dir != NULL)
520 return true;
521 parent_dentry = BPF_CORE_READ(filp_dentry, d_parent);
522 if (filp_dentry == parent_dentry)
523 break;
524 filp_dentry = parent_dentry;
525 }
526 return false;
527 }
528
is_dentry_allowed_for_filemod(struct dentry * file_dentry,u32 * device_id,u64 * file_ino)529 static INLINE bool is_dentry_allowed_for_filemod(struct dentry* file_dentry,
530 u32* device_id,
531 u64* file_ino)
532 {
533 u32 dev_id = BPF_CORE_READ(file_dentry, d_sb, s_dev);
534 *device_id = dev_id;
535 bool* allowed_device = bpf_map_lookup_elem(&allowed_devices, &dev_id);
536
537 if (allowed_device == NULL)
538 return false;
539
540 u64 ino = BPF_CORE_READ(file_dentry, d_inode, i_ino);
541 *file_ino = ino;
542 bool* allowed_file = bpf_map_lookup_elem(&allowed_file_inodes, &ino);
543
544 if (allowed_file == NULL)
545 if (!is_ancestor_in_allowed_inodes(BPF_CORE_READ(file_dentry, d_parent)))
546 return false;
547 return true;
548 }
549
550 SEC("kprobe/proc_sys_write")
BPF_KPROBE(kprobe__proc_sys_write,struct file * filp,const char * buf,size_t count,loff_t * ppos)551 ssize_t BPF_KPROBE(kprobe__proc_sys_write,
552 struct file* filp, const char* buf,
553 size_t count, loff_t* ppos)
554 {
555 struct bpf_func_stats_ctx stats_ctx;
556 bpf_stats_enter(&stats_ctx, profiler_bpf_proc_sys_write);
557
558 u32 pid = get_userspace_pid();
559 int zero = 0;
560 struct var_sysctl_data_t* sysctl_data =
561 bpf_map_lookup_elem(&data_heap, &zero);
562 if (!sysctl_data)
563 goto out;
564
565 struct task_struct* task = (struct task_struct*)bpf_get_current_task();
566 sysctl_data->meta.type = SYSCTL_EVENT;
567 void* payload = populate_var_metadata(&sysctl_data->meta, task, pid, sysctl_data->payload);
568 payload = populate_cgroup_info(&sysctl_data->cgroup_data, task, payload);
569
570 populate_ancestors(task, &sysctl_data->ancestors_info);
571
572 sysctl_data->sysctl_val_length = 0;
573 sysctl_data->sysctl_path_length = 0;
574
575 size_t sysctl_val_length = bpf_probe_read_str(payload, CTL_MAXNAME, buf);
576 barrier_var(sysctl_val_length);
577 if (sysctl_val_length <= CTL_MAXNAME) {
578 barrier_var(sysctl_val_length);
579 sysctl_data->sysctl_val_length = sysctl_val_length;
580 payload += sysctl_val_length;
581 }
582
583 size_t sysctl_path_length = bpf_probe_read_str(payload, MAX_PATH,
584 BPF_CORE_READ(filp, f_path.dentry, d_name.name));
585 barrier_var(sysctl_path_length);
586 if (sysctl_path_length <= MAX_PATH) {
587 barrier_var(sysctl_path_length);
588 sysctl_data->sysctl_path_length = sysctl_path_length;
589 payload += sysctl_path_length;
590 }
591
592 bpf_stats_pre_submit_var_perf_event(&stats_ctx, &sysctl_data->meta);
593 unsigned long data_len = payload - (void*)sysctl_data;
594 data_len = data_len > sizeof(struct var_sysctl_data_t)
595 ? sizeof(struct var_sysctl_data_t)
596 : data_len;
597 bpf_perf_event_output(ctx, &events, BPF_F_CURRENT_CPU, sysctl_data, data_len);
598 out:
599 bpf_stats_exit(&stats_ctx);
600 return 0;
601 }
602
603 SEC("tracepoint/syscalls/sys_enter_kill")
tracepoint__syscalls__sys_enter_kill(struct trace_event_raw_sys_enter * ctx)604 int tracepoint__syscalls__sys_enter_kill(struct trace_event_raw_sys_enter* ctx)
605 {
606 struct bpf_func_stats_ctx stats_ctx;
607
608 bpf_stats_enter(&stats_ctx, profiler_bpf_sys_enter_kill);
609 int pid = ctx->args[0];
610 int sig = ctx->args[1];
611 int ret = trace_var_sys_kill(ctx, pid, sig);
612 bpf_stats_exit(&stats_ctx);
613 return ret;
614 };
615
616 SEC("raw_tracepoint/sched_process_exit")
raw_tracepoint__sched_process_exit(void * ctx)617 int raw_tracepoint__sched_process_exit(void* ctx)
618 {
619 int zero = 0;
620 struct bpf_func_stats_ctx stats_ctx;
621 bpf_stats_enter(&stats_ctx, profiler_bpf_sched_process_exit);
622
623 u32 tpid = get_userspace_pid();
624
625 struct var_kill_data_arr_t* arr_struct = bpf_map_lookup_elem(&var_tpid_to_data, &tpid);
626 struct var_kill_data_t* kill_data = bpf_map_lookup_elem(&data_heap, &zero);
627
628 if (arr_struct == NULL || kill_data == NULL)
629 goto out;
630
631 struct task_struct* task = (struct task_struct*)bpf_get_current_task();
632 struct kernfs_node* proc_kernfs = BPF_CORE_READ(task, cgroups, dfl_cgrp, kn);
633
634 #ifdef UNROLL
635 #pragma unroll
636 #endif
637 for (int i = 0; i < ARRAY_SIZE(arr_struct->array); i++) {
638 struct var_kill_data_t* past_kill_data = &arr_struct->array[i];
639
640 if (past_kill_data != NULL && past_kill_data->kill_target_pid == tpid) {
641 bpf_probe_read(kill_data, sizeof(*past_kill_data), past_kill_data);
642 void* payload = kill_data->payload;
643 size_t offset = kill_data->payload_length;
644 if (offset >= MAX_METADATA_PAYLOAD_LEN + MAX_CGROUP_PAYLOAD_LEN)
645 return 0;
646 payload += offset;
647
648 kill_data->kill_target_name_length = 0;
649 kill_data->kill_target_cgroup_proc_length = 0;
650
651 size_t comm_length = bpf_core_read_str(payload, TASK_COMM_LEN, &task->comm);
652 barrier_var(comm_length);
653 if (comm_length <= TASK_COMM_LEN) {
654 barrier_var(comm_length);
655 kill_data->kill_target_name_length = comm_length;
656 payload += comm_length;
657 }
658
659 size_t cgroup_proc_length = bpf_probe_read_str(payload, KILL_TARGET_LEN,
660 BPF_CORE_READ(proc_kernfs, name));
661 barrier_var(cgroup_proc_length);
662 if (cgroup_proc_length <= KILL_TARGET_LEN) {
663 barrier_var(cgroup_proc_length);
664 kill_data->kill_target_cgroup_proc_length = cgroup_proc_length;
665 payload += cgroup_proc_length;
666 }
667
668 bpf_stats_pre_submit_var_perf_event(&stats_ctx, &kill_data->meta);
669 unsigned long data_len = (void*)payload - (void*)kill_data;
670 data_len = data_len > sizeof(struct var_kill_data_t)
671 ? sizeof(struct var_kill_data_t)
672 : data_len;
673 bpf_perf_event_output(ctx, &events, BPF_F_CURRENT_CPU, kill_data, data_len);
674 }
675 }
676 bpf_map_delete_elem(&var_tpid_to_data, &tpid);
677 out:
678 bpf_stats_exit(&stats_ctx);
679 return 0;
680 }
681
682 SEC("raw_tracepoint/sched_process_exec")
raw_tracepoint__sched_process_exec(struct bpf_raw_tracepoint_args * ctx)683 int raw_tracepoint__sched_process_exec(struct bpf_raw_tracepoint_args* ctx)
684 {
685 struct bpf_func_stats_ctx stats_ctx;
686 bpf_stats_enter(&stats_ctx, profiler_bpf_sched_process_exec);
687
688 struct linux_binprm* bprm = (struct linux_binprm*)ctx->args[2];
689 u64 inode = BPF_CORE_READ(bprm, file, f_inode, i_ino);
690
691 bool* should_filter_binprm = bpf_map_lookup_elem(&disallowed_exec_inodes, &inode);
692 if (should_filter_binprm != NULL)
693 goto out;
694
695 int zero = 0;
696 struct var_exec_data_t* proc_exec_data = bpf_map_lookup_elem(&data_heap, &zero);
697 if (!proc_exec_data)
698 goto out;
699
700 if (INODE_FILTER && inode != INODE_FILTER)
701 return 0;
702
703 u32 pid = get_userspace_pid();
704 struct task_struct* task = (struct task_struct*)bpf_get_current_task();
705
706 proc_exec_data->meta.type = EXEC_EVENT;
707 proc_exec_data->bin_path_length = 0;
708 proc_exec_data->cmdline_length = 0;
709 proc_exec_data->environment_length = 0;
710 void* payload = populate_var_metadata(&proc_exec_data->meta, task, pid,
711 proc_exec_data->payload);
712 payload = populate_cgroup_info(&proc_exec_data->cgroup_data, task, payload);
713
714 struct task_struct* parent_task = BPF_CORE_READ(task, real_parent);
715 proc_exec_data->parent_pid = BPF_CORE_READ(parent_task, tgid);
716 proc_exec_data->parent_uid = BPF_CORE_READ(parent_task, real_cred, uid.val);
717 proc_exec_data->parent_exec_id = BPF_CORE_READ(parent_task, self_exec_id);
718 proc_exec_data->parent_start_time = BPF_CORE_READ(parent_task, start_time);
719
720 const char* filename = BPF_CORE_READ(bprm, filename);
721 size_t bin_path_length = bpf_probe_read_str(payload, MAX_FILENAME_LEN, filename);
722 barrier_var(bin_path_length);
723 if (bin_path_length <= MAX_FILENAME_LEN) {
724 barrier_var(bin_path_length);
725 proc_exec_data->bin_path_length = bin_path_length;
726 payload += bin_path_length;
727 }
728
729 void* arg_start = (void*)BPF_CORE_READ(task, mm, arg_start);
730 void* arg_end = (void*)BPF_CORE_READ(task, mm, arg_end);
731 unsigned int cmdline_length = probe_read_lim(payload, arg_start,
732 arg_end - arg_start, MAX_ARGS_LEN);
733
734 if (cmdline_length <= MAX_ARGS_LEN) {
735 barrier_var(cmdline_length);
736 proc_exec_data->cmdline_length = cmdline_length;
737 payload += cmdline_length;
738 }
739
740 if (READ_ENVIRON_FROM_EXEC) {
741 void* env_start = (void*)BPF_CORE_READ(task, mm, env_start);
742 void* env_end = (void*)BPF_CORE_READ(task, mm, env_end);
743 unsigned long env_len = probe_read_lim(payload, env_start,
744 env_end - env_start, MAX_ENVIRON_LEN);
745 if (cmdline_length <= MAX_ENVIRON_LEN) {
746 proc_exec_data->environment_length = env_len;
747 payload += env_len;
748 }
749 }
750
751 bpf_stats_pre_submit_var_perf_event(&stats_ctx, &proc_exec_data->meta);
752 unsigned long data_len = payload - (void*)proc_exec_data;
753 data_len = data_len > sizeof(struct var_exec_data_t)
754 ? sizeof(struct var_exec_data_t)
755 : data_len;
756 bpf_perf_event_output(ctx, &events, BPF_F_CURRENT_CPU, proc_exec_data, data_len);
757 out:
758 bpf_stats_exit(&stats_ctx);
759 return 0;
760 }
761
762 SEC("kretprobe/do_filp_open")
kprobe_ret__do_filp_open(struct pt_regs * ctx)763 int kprobe_ret__do_filp_open(struct pt_regs* ctx)
764 {
765 struct bpf_func_stats_ctx stats_ctx;
766 bpf_stats_enter(&stats_ctx, profiler_bpf_do_filp_open_ret);
767
768 struct file* filp = (struct file*)PT_REGS_RC_CORE(ctx);
769
770 if (filp == NULL || IS_ERR(filp))
771 goto out;
772 unsigned int flags = BPF_CORE_READ(filp, f_flags);
773 if ((flags & (O_RDWR | O_WRONLY)) == 0)
774 goto out;
775 if ((flags & O_TMPFILE) > 0)
776 goto out;
777 struct inode* file_inode = BPF_CORE_READ(filp, f_inode);
778 umode_t mode = BPF_CORE_READ(file_inode, i_mode);
779 if (S_ISDIR(mode) || S_ISCHR(mode) || S_ISBLK(mode) || S_ISFIFO(mode) ||
780 S_ISSOCK(mode))
781 goto out;
782
783 struct dentry* filp_dentry = BPF_CORE_READ(filp, f_path.dentry);
784 u32 device_id = 0;
785 u64 file_ino = 0;
786 if (!is_dentry_allowed_for_filemod(filp_dentry, &device_id, &file_ino))
787 goto out;
788
789 int zero = 0;
790 struct var_filemod_data_t* filemod_data = bpf_map_lookup_elem(&data_heap, &zero);
791 if (!filemod_data)
792 goto out;
793
794 u32 pid = get_userspace_pid();
795 struct task_struct* task = (struct task_struct*)bpf_get_current_task();
796
797 filemod_data->meta.type = FILEMOD_EVENT;
798 filemod_data->fmod_type = FMOD_OPEN;
799 filemod_data->dst_flags = flags;
800 filemod_data->src_inode = 0;
801 filemod_data->dst_inode = file_ino;
802 filemod_data->src_device_id = 0;
803 filemod_data->dst_device_id = device_id;
804 filemod_data->src_filepath_length = 0;
805 filemod_data->dst_filepath_length = 0;
806
807 void* payload = populate_var_metadata(&filemod_data->meta, task, pid,
808 filemod_data->payload);
809 payload = populate_cgroup_info(&filemod_data->cgroup_data, task, payload);
810
811 size_t len = read_absolute_file_path_from_dentry(filp_dentry, payload);
812 barrier_var(len);
813 if (len <= MAX_FILEPATH_LENGTH) {
814 barrier_var(len);
815 payload += len;
816 filemod_data->dst_filepath_length = len;
817 }
818 bpf_stats_pre_submit_var_perf_event(&stats_ctx, &filemod_data->meta);
819 unsigned long data_len = payload - (void*)filemod_data;
820 data_len = data_len > sizeof(*filemod_data) ? sizeof(*filemod_data) : data_len;
821 bpf_perf_event_output(ctx, &events, BPF_F_CURRENT_CPU, filemod_data, data_len);
822 out:
823 bpf_stats_exit(&stats_ctx);
824 return 0;
825 }
826
827 SEC("kprobe/vfs_link")
BPF_KPROBE(kprobe__vfs_link,struct dentry * old_dentry,struct user_namespace * mnt_userns,struct inode * dir,struct dentry * new_dentry,struct inode ** delegated_inode)828 int BPF_KPROBE(kprobe__vfs_link,
829 struct dentry* old_dentry, struct user_namespace *mnt_userns,
830 struct inode* dir, struct dentry* new_dentry,
831 struct inode** delegated_inode)
832 {
833 struct bpf_func_stats_ctx stats_ctx;
834 bpf_stats_enter(&stats_ctx, profiler_bpf_vfs_link);
835
836 u32 src_device_id = 0;
837 u64 src_file_ino = 0;
838 u32 dst_device_id = 0;
839 u64 dst_file_ino = 0;
840 if (!is_dentry_allowed_for_filemod(old_dentry, &src_device_id, &src_file_ino) &&
841 !is_dentry_allowed_for_filemod(new_dentry, &dst_device_id, &dst_file_ino))
842 goto out;
843
844 int zero = 0;
845 struct var_filemod_data_t* filemod_data = bpf_map_lookup_elem(&data_heap, &zero);
846 if (!filemod_data)
847 goto out;
848
849 u32 pid = get_userspace_pid();
850 struct task_struct* task = (struct task_struct*)bpf_get_current_task();
851
852 filemod_data->meta.type = FILEMOD_EVENT;
853 filemod_data->fmod_type = FMOD_LINK;
854 filemod_data->dst_flags = 0;
855 filemod_data->src_inode = src_file_ino;
856 filemod_data->dst_inode = dst_file_ino;
857 filemod_data->src_device_id = src_device_id;
858 filemod_data->dst_device_id = dst_device_id;
859 filemod_data->src_filepath_length = 0;
860 filemod_data->dst_filepath_length = 0;
861
862 void* payload = populate_var_metadata(&filemod_data->meta, task, pid,
863 filemod_data->payload);
864 payload = populate_cgroup_info(&filemod_data->cgroup_data, task, payload);
865
866 size_t len = read_absolute_file_path_from_dentry(old_dentry, payload);
867 barrier_var(len);
868 if (len <= MAX_FILEPATH_LENGTH) {
869 barrier_var(len);
870 payload += len;
871 filemod_data->src_filepath_length = len;
872 }
873
874 len = read_absolute_file_path_from_dentry(new_dentry, payload);
875 barrier_var(len);
876 if (len <= MAX_FILEPATH_LENGTH) {
877 barrier_var(len);
878 payload += len;
879 filemod_data->dst_filepath_length = len;
880 }
881
882 bpf_stats_pre_submit_var_perf_event(&stats_ctx, &filemod_data->meta);
883 unsigned long data_len = payload - (void*)filemod_data;
884 data_len = data_len > sizeof(*filemod_data) ? sizeof(*filemod_data) : data_len;
885 bpf_perf_event_output(ctx, &events, BPF_F_CURRENT_CPU, filemod_data, data_len);
886 out:
887 bpf_stats_exit(&stats_ctx);
888 return 0;
889 }
890
891 SEC("kprobe/vfs_symlink")
BPF_KPROBE(kprobe__vfs_symlink,struct inode * dir,struct dentry * dentry,const char * oldname)892 int BPF_KPROBE(kprobe__vfs_symlink, struct inode* dir, struct dentry* dentry,
893 const char* oldname)
894 {
895 struct bpf_func_stats_ctx stats_ctx;
896 bpf_stats_enter(&stats_ctx, profiler_bpf_vfs_symlink);
897
898 u32 dst_device_id = 0;
899 u64 dst_file_ino = 0;
900 if (!is_dentry_allowed_for_filemod(dentry, &dst_device_id, &dst_file_ino))
901 goto out;
902
903 int zero = 0;
904 struct var_filemod_data_t* filemod_data = bpf_map_lookup_elem(&data_heap, &zero);
905 if (!filemod_data)
906 goto out;
907
908 u32 pid = get_userspace_pid();
909 struct task_struct* task = (struct task_struct*)bpf_get_current_task();
910
911 filemod_data->meta.type = FILEMOD_EVENT;
912 filemod_data->fmod_type = FMOD_SYMLINK;
913 filemod_data->dst_flags = 0;
914 filemod_data->src_inode = 0;
915 filemod_data->dst_inode = dst_file_ino;
916 filemod_data->src_device_id = 0;
917 filemod_data->dst_device_id = dst_device_id;
918 filemod_data->src_filepath_length = 0;
919 filemod_data->dst_filepath_length = 0;
920
921 void* payload = populate_var_metadata(&filemod_data->meta, task, pid,
922 filemod_data->payload);
923 payload = populate_cgroup_info(&filemod_data->cgroup_data, task, payload);
924
925 size_t len = bpf_probe_read_str(payload, MAX_FILEPATH_LENGTH, oldname);
926 barrier_var(len);
927 if (len <= MAX_FILEPATH_LENGTH) {
928 barrier_var(len);
929 payload += len;
930 filemod_data->src_filepath_length = len;
931 }
932 len = read_absolute_file_path_from_dentry(dentry, payload);
933 barrier_var(len);
934 if (len <= MAX_FILEPATH_LENGTH) {
935 barrier_var(len);
936 payload += len;
937 filemod_data->dst_filepath_length = len;
938 }
939 bpf_stats_pre_submit_var_perf_event(&stats_ctx, &filemod_data->meta);
940 unsigned long data_len = payload - (void*)filemod_data;
941 data_len = data_len > sizeof(*filemod_data) ? sizeof(*filemod_data) : data_len;
942 bpf_perf_event_output(ctx, &events, BPF_F_CURRENT_CPU, filemod_data, data_len);
943 out:
944 bpf_stats_exit(&stats_ctx);
945 return 0;
946 }
947
948 SEC("raw_tracepoint/sched_process_fork")
raw_tracepoint__sched_process_fork(struct bpf_raw_tracepoint_args * ctx)949 int raw_tracepoint__sched_process_fork(struct bpf_raw_tracepoint_args* ctx)
950 {
951 struct bpf_func_stats_ctx stats_ctx;
952 bpf_stats_enter(&stats_ctx, profiler_bpf_sched_process_fork);
953
954 int zero = 0;
955 struct var_fork_data_t* fork_data = bpf_map_lookup_elem(&data_heap, &zero);
956 if (!fork_data)
957 goto out;
958
959 struct task_struct* parent = (struct task_struct*)ctx->args[0];
960 struct task_struct* child = (struct task_struct*)ctx->args[1];
961 fork_data->meta.type = FORK_EVENT;
962
963 void* payload = populate_var_metadata(&fork_data->meta, child,
964 BPF_CORE_READ(child, pid), fork_data->payload);
965 fork_data->parent_pid = BPF_CORE_READ(parent, pid);
966 fork_data->parent_exec_id = BPF_CORE_READ(parent, self_exec_id);
967 fork_data->parent_start_time = BPF_CORE_READ(parent, start_time);
968 bpf_stats_pre_submit_var_perf_event(&stats_ctx, &fork_data->meta);
969
970 unsigned long data_len = payload - (void*)fork_data;
971 data_len = data_len > sizeof(*fork_data) ? sizeof(*fork_data) : data_len;
972 bpf_perf_event_output(ctx, &events, BPF_F_CURRENT_CPU, fork_data, data_len);
973 out:
974 bpf_stats_exit(&stats_ctx);
975 return 0;
976 }
977 char _license[] SEC("license") = "GPL";
978