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179a0cc4 | 1 | // SPDX-License-Identifier: GPL-2.0 |
2541517c | 2 | /* Copyright (c) 2011-2015 PLUMgrid, http://plumgrid.com |
0515e599 | 3 | * Copyright (c) 2016 Facebook |
2541517c AS |
4 | */ |
5 | #include <linux/kernel.h> | |
6 | #include <linux/types.h> | |
7 | #include <linux/slab.h> | |
8 | #include <linux/bpf.h> | |
0515e599 | 9 | #include <linux/bpf_perf_event.h> |
2541517c AS |
10 | #include <linux/filter.h> |
11 | #include <linux/uaccess.h> | |
9c959c86 | 12 | #include <linux/ctype.h> |
9802d865 | 13 | #include <linux/kprobes.h> |
41bdc4b4 | 14 | #include <linux/syscalls.h> |
540adea3 | 15 | #include <linux/error-injection.h> |
9802d865 | 16 | |
c7b6f29b NA |
17 | #include <asm/tlb.h> |
18 | ||
9802d865 | 19 | #include "trace_probe.h" |
2541517c AS |
20 | #include "trace.h" |
21 | ||
e672db03 SF |
22 | #define bpf_event_rcu_dereference(p) \ |
23 | rcu_dereference_protected(p, lockdep_is_held(&bpf_event_mutex)) | |
24 | ||
a38d1107 MM |
25 | #ifdef CONFIG_MODULES |
26 | struct bpf_trace_module { | |
27 | struct module *module; | |
28 | struct list_head list; | |
29 | }; | |
30 | ||
31 | static LIST_HEAD(bpf_trace_modules); | |
32 | static DEFINE_MUTEX(bpf_module_mutex); | |
33 | ||
34 | static struct bpf_raw_event_map *bpf_get_raw_tracepoint_module(const char *name) | |
35 | { | |
36 | struct bpf_raw_event_map *btp, *ret = NULL; | |
37 | struct bpf_trace_module *btm; | |
38 | unsigned int i; | |
39 | ||
40 | mutex_lock(&bpf_module_mutex); | |
41 | list_for_each_entry(btm, &bpf_trace_modules, list) { | |
42 | for (i = 0; i < btm->module->num_bpf_raw_events; ++i) { | |
43 | btp = &btm->module->bpf_raw_events[i]; | |
44 | if (!strcmp(btp->tp->name, name)) { | |
45 | if (try_module_get(btm->module)) | |
46 | ret = btp; | |
47 | goto out; | |
48 | } | |
49 | } | |
50 | } | |
51 | out: | |
52 | mutex_unlock(&bpf_module_mutex); | |
53 | return ret; | |
54 | } | |
55 | #else | |
56 | static struct bpf_raw_event_map *bpf_get_raw_tracepoint_module(const char *name) | |
57 | { | |
58 | return NULL; | |
59 | } | |
60 | #endif /* CONFIG_MODULES */ | |
61 | ||
035226b9 | 62 | u64 bpf_get_stackid(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5); |
c195651e | 63 | u64 bpf_get_stack(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5); |
035226b9 | 64 | |
2541517c AS |
65 | /** |
66 | * trace_call_bpf - invoke BPF program | |
e87c6bc3 | 67 | * @call: tracepoint event |
2541517c AS |
68 | * @ctx: opaque context pointer |
69 | * | |
70 | * kprobe handlers execute BPF programs via this helper. | |
71 | * Can be used from static tracepoints in the future. | |
72 | * | |
73 | * Return: BPF programs always return an integer which is interpreted by | |
74 | * kprobe handler as: | |
75 | * 0 - return from kprobe (event is filtered out) | |
76 | * 1 - store kprobe event into ring buffer | |
77 | * Other values are reserved and currently alias to 1 | |
78 | */ | |
e87c6bc3 | 79 | unsigned int trace_call_bpf(struct trace_event_call *call, void *ctx) |
2541517c AS |
80 | { |
81 | unsigned int ret; | |
82 | ||
83 | if (in_nmi()) /* not supported yet */ | |
84 | return 1; | |
85 | ||
86 | preempt_disable(); | |
87 | ||
88 | if (unlikely(__this_cpu_inc_return(bpf_prog_active) != 1)) { | |
89 | /* | |
90 | * since some bpf program is already running on this cpu, | |
91 | * don't call into another bpf program (same or different) | |
92 | * and don't send kprobe event into ring-buffer, | |
93 | * so return zero here | |
94 | */ | |
95 | ret = 0; | |
96 | goto out; | |
97 | } | |
98 | ||
e87c6bc3 YS |
99 | /* |
100 | * Instead of moving rcu_read_lock/rcu_dereference/rcu_read_unlock | |
101 | * to all call sites, we did a bpf_prog_array_valid() there to check | |
102 | * whether call->prog_array is empty or not, which is | |
103 | * a heurisitc to speed up execution. | |
104 | * | |
105 | * If bpf_prog_array_valid() fetched prog_array was | |
106 | * non-NULL, we go into trace_call_bpf() and do the actual | |
107 | * proper rcu_dereference() under RCU lock. | |
108 | * If it turns out that prog_array is NULL then, we bail out. | |
109 | * For the opposite, if the bpf_prog_array_valid() fetched pointer | |
110 | * was NULL, you'll skip the prog_array with the risk of missing | |
111 | * out of events when it was updated in between this and the | |
112 | * rcu_dereference() which is accepted risk. | |
113 | */ | |
114 | ret = BPF_PROG_RUN_ARRAY_CHECK(call->prog_array, ctx, BPF_PROG_RUN); | |
2541517c AS |
115 | |
116 | out: | |
117 | __this_cpu_dec(bpf_prog_active); | |
118 | preempt_enable(); | |
119 | ||
120 | return ret; | |
121 | } | |
122 | EXPORT_SYMBOL_GPL(trace_call_bpf); | |
123 | ||
9802d865 JB |
124 | #ifdef CONFIG_BPF_KPROBE_OVERRIDE |
125 | BPF_CALL_2(bpf_override_return, struct pt_regs *, regs, unsigned long, rc) | |
126 | { | |
9802d865 | 127 | regs_set_return_value(regs, rc); |
540adea3 | 128 | override_function_with_return(regs); |
9802d865 JB |
129 | return 0; |
130 | } | |
131 | ||
132 | static const struct bpf_func_proto bpf_override_return_proto = { | |
133 | .func = bpf_override_return, | |
134 | .gpl_only = true, | |
135 | .ret_type = RET_INTEGER, | |
136 | .arg1_type = ARG_PTR_TO_CTX, | |
137 | .arg2_type = ARG_ANYTHING, | |
138 | }; | |
139 | #endif | |
140 | ||
6ae08ae3 DB |
141 | BPF_CALL_3(bpf_probe_read_user, void *, dst, u32, size, |
142 | const void __user *, unsafe_ptr) | |
2541517c | 143 | { |
6ae08ae3 | 144 | int ret = probe_user_read(dst, unsafe_ptr, size); |
2541517c | 145 | |
6ae08ae3 DB |
146 | if (unlikely(ret < 0)) |
147 | memset(dst, 0, size); | |
148 | ||
149 | return ret; | |
150 | } | |
151 | ||
152 | static const struct bpf_func_proto bpf_probe_read_user_proto = { | |
153 | .func = bpf_probe_read_user, | |
154 | .gpl_only = true, | |
155 | .ret_type = RET_INTEGER, | |
156 | .arg1_type = ARG_PTR_TO_UNINIT_MEM, | |
157 | .arg2_type = ARG_CONST_SIZE_OR_ZERO, | |
158 | .arg3_type = ARG_ANYTHING, | |
159 | }; | |
160 | ||
161 | BPF_CALL_3(bpf_probe_read_user_str, void *, dst, u32, size, | |
162 | const void __user *, unsafe_ptr) | |
163 | { | |
164 | int ret = strncpy_from_unsafe_user(dst, unsafe_ptr, size); | |
165 | ||
166 | if (unlikely(ret < 0)) | |
167 | memset(dst, 0, size); | |
168 | ||
169 | return ret; | |
170 | } | |
171 | ||
172 | static const struct bpf_func_proto bpf_probe_read_user_str_proto = { | |
173 | .func = bpf_probe_read_user_str, | |
174 | .gpl_only = true, | |
175 | .ret_type = RET_INTEGER, | |
176 | .arg1_type = ARG_PTR_TO_UNINIT_MEM, | |
177 | .arg2_type = ARG_CONST_SIZE_OR_ZERO, | |
178 | .arg3_type = ARG_ANYTHING, | |
179 | }; | |
180 | ||
181 | static __always_inline int | |
182 | bpf_probe_read_kernel_common(void *dst, u32 size, const void *unsafe_ptr, | |
183 | const bool compat) | |
184 | { | |
185 | int ret = security_locked_down(LOCKDOWN_BPF_READ); | |
9d1f8be5 | 186 | |
6ae08ae3 DB |
187 | if (unlikely(ret < 0)) |
188 | goto out; | |
189 | ret = compat ? probe_kernel_read(dst, unsafe_ptr, size) : | |
190 | probe_kernel_read_strict(dst, unsafe_ptr, size); | |
074f528e | 191 | if (unlikely(ret < 0)) |
9d1f8be5 | 192 | out: |
074f528e | 193 | memset(dst, 0, size); |
6ae08ae3 DB |
194 | return ret; |
195 | } | |
074f528e | 196 | |
6ae08ae3 DB |
197 | BPF_CALL_3(bpf_probe_read_kernel, void *, dst, u32, size, |
198 | const void *, unsafe_ptr) | |
199 | { | |
200 | return bpf_probe_read_kernel_common(dst, size, unsafe_ptr, false); | |
201 | } | |
202 | ||
203 | static const struct bpf_func_proto bpf_probe_read_kernel_proto = { | |
204 | .func = bpf_probe_read_kernel, | |
205 | .gpl_only = true, | |
206 | .ret_type = RET_INTEGER, | |
207 | .arg1_type = ARG_PTR_TO_UNINIT_MEM, | |
208 | .arg2_type = ARG_CONST_SIZE_OR_ZERO, | |
209 | .arg3_type = ARG_ANYTHING, | |
210 | }; | |
211 | ||
212 | BPF_CALL_3(bpf_probe_read_compat, void *, dst, u32, size, | |
213 | const void *, unsafe_ptr) | |
214 | { | |
215 | return bpf_probe_read_kernel_common(dst, size, unsafe_ptr, true); | |
216 | } | |
217 | ||
218 | static const struct bpf_func_proto bpf_probe_read_compat_proto = { | |
219 | .func = bpf_probe_read_compat, | |
220 | .gpl_only = true, | |
221 | .ret_type = RET_INTEGER, | |
222 | .arg1_type = ARG_PTR_TO_UNINIT_MEM, | |
223 | .arg2_type = ARG_CONST_SIZE_OR_ZERO, | |
224 | .arg3_type = ARG_ANYTHING, | |
225 | }; | |
226 | ||
227 | static __always_inline int | |
228 | bpf_probe_read_kernel_str_common(void *dst, u32 size, const void *unsafe_ptr, | |
229 | const bool compat) | |
230 | { | |
231 | int ret = security_locked_down(LOCKDOWN_BPF_READ); | |
232 | ||
233 | if (unlikely(ret < 0)) | |
234 | goto out; | |
235 | /* | |
236 | * The strncpy_from_unsafe_*() call will likely not fill the entire | |
237 | * buffer, but that's okay in this circumstance as we're probing | |
238 | * arbitrary memory anyway similar to bpf_probe_read_*() and might | |
239 | * as well probe the stack. Thus, memory is explicitly cleared | |
240 | * only in error case, so that improper users ignoring return | |
241 | * code altogether don't copy garbage; otherwise length of string | |
242 | * is returned that can be used for bpf_perf_event_output() et al. | |
243 | */ | |
244 | ret = compat ? strncpy_from_unsafe(dst, unsafe_ptr, size) : | |
245 | strncpy_from_unsafe_strict(dst, unsafe_ptr, size); | |
246 | if (unlikely(ret < 0)) | |
247 | out: | |
248 | memset(dst, 0, size); | |
074f528e | 249 | return ret; |
2541517c AS |
250 | } |
251 | ||
6ae08ae3 DB |
252 | BPF_CALL_3(bpf_probe_read_kernel_str, void *, dst, u32, size, |
253 | const void *, unsafe_ptr) | |
254 | { | |
255 | return bpf_probe_read_kernel_str_common(dst, size, unsafe_ptr, false); | |
256 | } | |
257 | ||
258 | static const struct bpf_func_proto bpf_probe_read_kernel_str_proto = { | |
259 | .func = bpf_probe_read_kernel_str, | |
260 | .gpl_only = true, | |
261 | .ret_type = RET_INTEGER, | |
262 | .arg1_type = ARG_PTR_TO_UNINIT_MEM, | |
263 | .arg2_type = ARG_CONST_SIZE_OR_ZERO, | |
264 | .arg3_type = ARG_ANYTHING, | |
265 | }; | |
266 | ||
267 | BPF_CALL_3(bpf_probe_read_compat_str, void *, dst, u32, size, | |
268 | const void *, unsafe_ptr) | |
269 | { | |
270 | return bpf_probe_read_kernel_str_common(dst, size, unsafe_ptr, true); | |
271 | } | |
272 | ||
273 | static const struct bpf_func_proto bpf_probe_read_compat_str_proto = { | |
274 | .func = bpf_probe_read_compat_str, | |
2541517c AS |
275 | .gpl_only = true, |
276 | .ret_type = RET_INTEGER, | |
39f19ebb | 277 | .arg1_type = ARG_PTR_TO_UNINIT_MEM, |
9c019e2b | 278 | .arg2_type = ARG_CONST_SIZE_OR_ZERO, |
2541517c AS |
279 | .arg3_type = ARG_ANYTHING, |
280 | }; | |
281 | ||
eb1b6688 | 282 | BPF_CALL_3(bpf_probe_write_user, void __user *, unsafe_ptr, const void *, src, |
f3694e00 | 283 | u32, size) |
96ae5227 | 284 | { |
96ae5227 SD |
285 | /* |
286 | * Ensure we're in user context which is safe for the helper to | |
287 | * run. This helper has no business in a kthread. | |
288 | * | |
289 | * access_ok() should prevent writing to non-user memory, but in | |
290 | * some situations (nommu, temporary switch, etc) access_ok() does | |
291 | * not provide enough validation, hence the check on KERNEL_DS. | |
c7b6f29b NA |
292 | * |
293 | * nmi_uaccess_okay() ensures the probe is not run in an interim | |
294 | * state, when the task or mm are switched. This is specifically | |
295 | * required to prevent the use of temporary mm. | |
96ae5227 SD |
296 | */ |
297 | ||
298 | if (unlikely(in_interrupt() || | |
299 | current->flags & (PF_KTHREAD | PF_EXITING))) | |
300 | return -EPERM; | |
db68ce10 | 301 | if (unlikely(uaccess_kernel())) |
96ae5227 | 302 | return -EPERM; |
c7b6f29b NA |
303 | if (unlikely(!nmi_uaccess_okay())) |
304 | return -EPERM; | |
96ae5227 | 305 | |
eb1b6688 | 306 | return probe_user_write(unsafe_ptr, src, size); |
96ae5227 SD |
307 | } |
308 | ||
309 | static const struct bpf_func_proto bpf_probe_write_user_proto = { | |
310 | .func = bpf_probe_write_user, | |
311 | .gpl_only = true, | |
312 | .ret_type = RET_INTEGER, | |
313 | .arg1_type = ARG_ANYTHING, | |
39f19ebb AS |
314 | .arg2_type = ARG_PTR_TO_MEM, |
315 | .arg3_type = ARG_CONST_SIZE, | |
96ae5227 SD |
316 | }; |
317 | ||
318 | static const struct bpf_func_proto *bpf_get_probe_write_proto(void) | |
319 | { | |
320 | pr_warn_ratelimited("%s[%d] is installing a program with bpf_probe_write_user helper that may corrupt user memory!", | |
321 | current->comm, task_pid_nr(current)); | |
322 | ||
323 | return &bpf_probe_write_user_proto; | |
324 | } | |
325 | ||
9c959c86 | 326 | /* |
7bda4b40 JF |
327 | * Only limited trace_printk() conversion specifiers allowed: |
328 | * %d %i %u %x %ld %li %lu %lx %lld %lli %llu %llx %p %s | |
9c959c86 | 329 | */ |
f3694e00 DB |
330 | BPF_CALL_5(bpf_trace_printk, char *, fmt, u32, fmt_size, u64, arg1, |
331 | u64, arg2, u64, arg3) | |
9c959c86 | 332 | { |
8d3b7dce | 333 | bool str_seen = false; |
9c959c86 AS |
334 | int mod[3] = {}; |
335 | int fmt_cnt = 0; | |
8d3b7dce AS |
336 | u64 unsafe_addr; |
337 | char buf[64]; | |
9c959c86 AS |
338 | int i; |
339 | ||
340 | /* | |
341 | * bpf_check()->check_func_arg()->check_stack_boundary() | |
342 | * guarantees that fmt points to bpf program stack, | |
343 | * fmt_size bytes of it were initialized and fmt_size > 0 | |
344 | */ | |
345 | if (fmt[--fmt_size] != 0) | |
346 | return -EINVAL; | |
347 | ||
348 | /* check format string for allowed specifiers */ | |
349 | for (i = 0; i < fmt_size; i++) { | |
350 | if ((!isprint(fmt[i]) && !isspace(fmt[i])) || !isascii(fmt[i])) | |
351 | return -EINVAL; | |
352 | ||
353 | if (fmt[i] != '%') | |
354 | continue; | |
355 | ||
356 | if (fmt_cnt >= 3) | |
357 | return -EINVAL; | |
358 | ||
359 | /* fmt[i] != 0 && fmt[last] == 0, so we can access fmt[i + 1] */ | |
360 | i++; | |
361 | if (fmt[i] == 'l') { | |
362 | mod[fmt_cnt]++; | |
363 | i++; | |
8d3b7dce | 364 | } else if (fmt[i] == 'p' || fmt[i] == 's') { |
9c959c86 | 365 | mod[fmt_cnt]++; |
1efb6ee3 MP |
366 | /* disallow any further format extensions */ |
367 | if (fmt[i + 1] != 0 && | |
368 | !isspace(fmt[i + 1]) && | |
369 | !ispunct(fmt[i + 1])) | |
9c959c86 AS |
370 | return -EINVAL; |
371 | fmt_cnt++; | |
1efb6ee3 | 372 | if (fmt[i] == 's') { |
8d3b7dce AS |
373 | if (str_seen) |
374 | /* allow only one '%s' per fmt string */ | |
375 | return -EINVAL; | |
376 | str_seen = true; | |
377 | ||
378 | switch (fmt_cnt) { | |
379 | case 1: | |
f3694e00 DB |
380 | unsafe_addr = arg1; |
381 | arg1 = (long) buf; | |
8d3b7dce AS |
382 | break; |
383 | case 2: | |
f3694e00 DB |
384 | unsafe_addr = arg2; |
385 | arg2 = (long) buf; | |
8d3b7dce AS |
386 | break; |
387 | case 3: | |
f3694e00 DB |
388 | unsafe_addr = arg3; |
389 | arg3 = (long) buf; | |
8d3b7dce AS |
390 | break; |
391 | } | |
392 | buf[0] = 0; | |
393 | strncpy_from_unsafe(buf, | |
394 | (void *) (long) unsafe_addr, | |
395 | sizeof(buf)); | |
396 | } | |
9c959c86 AS |
397 | continue; |
398 | } | |
399 | ||
400 | if (fmt[i] == 'l') { | |
401 | mod[fmt_cnt]++; | |
402 | i++; | |
403 | } | |
404 | ||
7bda4b40 JF |
405 | if (fmt[i] != 'i' && fmt[i] != 'd' && |
406 | fmt[i] != 'u' && fmt[i] != 'x') | |
9c959c86 AS |
407 | return -EINVAL; |
408 | fmt_cnt++; | |
409 | } | |
410 | ||
88a5c690 DB |
411 | /* Horrid workaround for getting va_list handling working with different |
412 | * argument type combinations generically for 32 and 64 bit archs. | |
413 | */ | |
414 | #define __BPF_TP_EMIT() __BPF_ARG3_TP() | |
415 | #define __BPF_TP(...) \ | |
eefa864a | 416 | __trace_printk(0 /* Fake ip */, \ |
88a5c690 DB |
417 | fmt, ##__VA_ARGS__) |
418 | ||
419 | #define __BPF_ARG1_TP(...) \ | |
420 | ((mod[0] == 2 || (mod[0] == 1 && __BITS_PER_LONG == 64)) \ | |
421 | ? __BPF_TP(arg1, ##__VA_ARGS__) \ | |
422 | : ((mod[0] == 1 || (mod[0] == 0 && __BITS_PER_LONG == 32)) \ | |
423 | ? __BPF_TP((long)arg1, ##__VA_ARGS__) \ | |
424 | : __BPF_TP((u32)arg1, ##__VA_ARGS__))) | |
425 | ||
426 | #define __BPF_ARG2_TP(...) \ | |
427 | ((mod[1] == 2 || (mod[1] == 1 && __BITS_PER_LONG == 64)) \ | |
428 | ? __BPF_ARG1_TP(arg2, ##__VA_ARGS__) \ | |
429 | : ((mod[1] == 1 || (mod[1] == 0 && __BITS_PER_LONG == 32)) \ | |
430 | ? __BPF_ARG1_TP((long)arg2, ##__VA_ARGS__) \ | |
431 | : __BPF_ARG1_TP((u32)arg2, ##__VA_ARGS__))) | |
432 | ||
433 | #define __BPF_ARG3_TP(...) \ | |
434 | ((mod[2] == 2 || (mod[2] == 1 && __BITS_PER_LONG == 64)) \ | |
435 | ? __BPF_ARG2_TP(arg3, ##__VA_ARGS__) \ | |
436 | : ((mod[2] == 1 || (mod[2] == 0 && __BITS_PER_LONG == 32)) \ | |
437 | ? __BPF_ARG2_TP((long)arg3, ##__VA_ARGS__) \ | |
438 | : __BPF_ARG2_TP((u32)arg3, ##__VA_ARGS__))) | |
439 | ||
440 | return __BPF_TP_EMIT(); | |
9c959c86 AS |
441 | } |
442 | ||
443 | static const struct bpf_func_proto bpf_trace_printk_proto = { | |
444 | .func = bpf_trace_printk, | |
445 | .gpl_only = true, | |
446 | .ret_type = RET_INTEGER, | |
39f19ebb AS |
447 | .arg1_type = ARG_PTR_TO_MEM, |
448 | .arg2_type = ARG_CONST_SIZE, | |
9c959c86 AS |
449 | }; |
450 | ||
0756ea3e AS |
451 | const struct bpf_func_proto *bpf_get_trace_printk_proto(void) |
452 | { | |
453 | /* | |
454 | * this program might be calling bpf_trace_printk, | |
455 | * so allocate per-cpu printk buffers | |
456 | */ | |
457 | trace_printk_init_buffers(); | |
458 | ||
459 | return &bpf_trace_printk_proto; | |
460 | } | |
461 | ||
908432ca YS |
462 | static __always_inline int |
463 | get_map_perf_counter(struct bpf_map *map, u64 flags, | |
464 | u64 *value, u64 *enabled, u64 *running) | |
35578d79 | 465 | { |
35578d79 | 466 | struct bpf_array *array = container_of(map, struct bpf_array, map); |
6816a7ff DB |
467 | unsigned int cpu = smp_processor_id(); |
468 | u64 index = flags & BPF_F_INDEX_MASK; | |
3b1efb19 | 469 | struct bpf_event_entry *ee; |
35578d79 | 470 | |
6816a7ff DB |
471 | if (unlikely(flags & ~(BPF_F_INDEX_MASK))) |
472 | return -EINVAL; | |
473 | if (index == BPF_F_CURRENT_CPU) | |
474 | index = cpu; | |
35578d79 KX |
475 | if (unlikely(index >= array->map.max_entries)) |
476 | return -E2BIG; | |
477 | ||
3b1efb19 | 478 | ee = READ_ONCE(array->ptrs[index]); |
1ca1cc98 | 479 | if (!ee) |
35578d79 KX |
480 | return -ENOENT; |
481 | ||
908432ca YS |
482 | return perf_event_read_local(ee->event, value, enabled, running); |
483 | } | |
484 | ||
485 | BPF_CALL_2(bpf_perf_event_read, struct bpf_map *, map, u64, flags) | |
486 | { | |
487 | u64 value = 0; | |
488 | int err; | |
489 | ||
490 | err = get_map_perf_counter(map, flags, &value, NULL, NULL); | |
35578d79 | 491 | /* |
f91840a3 AS |
492 | * this api is ugly since we miss [-22..-2] range of valid |
493 | * counter values, but that's uapi | |
35578d79 | 494 | */ |
f91840a3 AS |
495 | if (err) |
496 | return err; | |
497 | return value; | |
35578d79 KX |
498 | } |
499 | ||
62544ce8 | 500 | static const struct bpf_func_proto bpf_perf_event_read_proto = { |
35578d79 | 501 | .func = bpf_perf_event_read, |
1075ef59 | 502 | .gpl_only = true, |
35578d79 KX |
503 | .ret_type = RET_INTEGER, |
504 | .arg1_type = ARG_CONST_MAP_PTR, | |
505 | .arg2_type = ARG_ANYTHING, | |
506 | }; | |
507 | ||
908432ca YS |
508 | BPF_CALL_4(bpf_perf_event_read_value, struct bpf_map *, map, u64, flags, |
509 | struct bpf_perf_event_value *, buf, u32, size) | |
510 | { | |
511 | int err = -EINVAL; | |
512 | ||
513 | if (unlikely(size != sizeof(struct bpf_perf_event_value))) | |
514 | goto clear; | |
515 | err = get_map_perf_counter(map, flags, &buf->counter, &buf->enabled, | |
516 | &buf->running); | |
517 | if (unlikely(err)) | |
518 | goto clear; | |
519 | return 0; | |
520 | clear: | |
521 | memset(buf, 0, size); | |
522 | return err; | |
523 | } | |
524 | ||
525 | static const struct bpf_func_proto bpf_perf_event_read_value_proto = { | |
526 | .func = bpf_perf_event_read_value, | |
527 | .gpl_only = true, | |
528 | .ret_type = RET_INTEGER, | |
529 | .arg1_type = ARG_CONST_MAP_PTR, | |
530 | .arg2_type = ARG_ANYTHING, | |
531 | .arg3_type = ARG_PTR_TO_UNINIT_MEM, | |
532 | .arg4_type = ARG_CONST_SIZE, | |
533 | }; | |
534 | ||
8e7a3920 DB |
535 | static __always_inline u64 |
536 | __bpf_perf_event_output(struct pt_regs *regs, struct bpf_map *map, | |
283ca526 | 537 | u64 flags, struct perf_sample_data *sd) |
a43eec30 | 538 | { |
a43eec30 | 539 | struct bpf_array *array = container_of(map, struct bpf_array, map); |
d7931330 | 540 | unsigned int cpu = smp_processor_id(); |
1e33759c | 541 | u64 index = flags & BPF_F_INDEX_MASK; |
3b1efb19 | 542 | struct bpf_event_entry *ee; |
a43eec30 | 543 | struct perf_event *event; |
a43eec30 | 544 | |
1e33759c | 545 | if (index == BPF_F_CURRENT_CPU) |
d7931330 | 546 | index = cpu; |
a43eec30 AS |
547 | if (unlikely(index >= array->map.max_entries)) |
548 | return -E2BIG; | |
549 | ||
3b1efb19 | 550 | ee = READ_ONCE(array->ptrs[index]); |
1ca1cc98 | 551 | if (!ee) |
a43eec30 AS |
552 | return -ENOENT; |
553 | ||
3b1efb19 | 554 | event = ee->event; |
a43eec30 AS |
555 | if (unlikely(event->attr.type != PERF_TYPE_SOFTWARE || |
556 | event->attr.config != PERF_COUNT_SW_BPF_OUTPUT)) | |
557 | return -EINVAL; | |
558 | ||
d7931330 | 559 | if (unlikely(event->oncpu != cpu)) |
a43eec30 AS |
560 | return -EOPNOTSUPP; |
561 | ||
56201969 | 562 | return perf_event_output(event, sd, regs); |
a43eec30 AS |
563 | } |
564 | ||
9594dc3c MM |
565 | /* |
566 | * Support executing tracepoints in normal, irq, and nmi context that each call | |
567 | * bpf_perf_event_output | |
568 | */ | |
569 | struct bpf_trace_sample_data { | |
570 | struct perf_sample_data sds[3]; | |
571 | }; | |
572 | ||
573 | static DEFINE_PER_CPU(struct bpf_trace_sample_data, bpf_trace_sds); | |
574 | static DEFINE_PER_CPU(int, bpf_trace_nest_level); | |
f3694e00 DB |
575 | BPF_CALL_5(bpf_perf_event_output, struct pt_regs *, regs, struct bpf_map *, map, |
576 | u64, flags, void *, data, u64, size) | |
8e7a3920 | 577 | { |
9594dc3c MM |
578 | struct bpf_trace_sample_data *sds = this_cpu_ptr(&bpf_trace_sds); |
579 | int nest_level = this_cpu_inc_return(bpf_trace_nest_level); | |
8e7a3920 DB |
580 | struct perf_raw_record raw = { |
581 | .frag = { | |
582 | .size = size, | |
583 | .data = data, | |
584 | }, | |
585 | }; | |
9594dc3c MM |
586 | struct perf_sample_data *sd; |
587 | int err; | |
8e7a3920 | 588 | |
9594dc3c MM |
589 | if (WARN_ON_ONCE(nest_level > ARRAY_SIZE(sds->sds))) { |
590 | err = -EBUSY; | |
591 | goto out; | |
592 | } | |
593 | ||
594 | sd = &sds->sds[nest_level - 1]; | |
595 | ||
596 | if (unlikely(flags & ~(BPF_F_INDEX_MASK))) { | |
597 | err = -EINVAL; | |
598 | goto out; | |
599 | } | |
8e7a3920 | 600 | |
283ca526 DB |
601 | perf_sample_data_init(sd, 0, 0); |
602 | sd->raw = &raw; | |
603 | ||
9594dc3c MM |
604 | err = __bpf_perf_event_output(regs, map, flags, sd); |
605 | ||
606 | out: | |
607 | this_cpu_dec(bpf_trace_nest_level); | |
608 | return err; | |
8e7a3920 DB |
609 | } |
610 | ||
a43eec30 AS |
611 | static const struct bpf_func_proto bpf_perf_event_output_proto = { |
612 | .func = bpf_perf_event_output, | |
1075ef59 | 613 | .gpl_only = true, |
a43eec30 AS |
614 | .ret_type = RET_INTEGER, |
615 | .arg1_type = ARG_PTR_TO_CTX, | |
616 | .arg2_type = ARG_CONST_MAP_PTR, | |
617 | .arg3_type = ARG_ANYTHING, | |
39f19ebb | 618 | .arg4_type = ARG_PTR_TO_MEM, |
a60dd35d | 619 | .arg5_type = ARG_CONST_SIZE_OR_ZERO, |
a43eec30 AS |
620 | }; |
621 | ||
768fb61f AZ |
622 | static DEFINE_PER_CPU(int, bpf_event_output_nest_level); |
623 | struct bpf_nested_pt_regs { | |
624 | struct pt_regs regs[3]; | |
625 | }; | |
626 | static DEFINE_PER_CPU(struct bpf_nested_pt_regs, bpf_pt_regs); | |
627 | static DEFINE_PER_CPU(struct bpf_trace_sample_data, bpf_misc_sds); | |
bd570ff9 | 628 | |
555c8a86 DB |
629 | u64 bpf_event_output(struct bpf_map *map, u64 flags, void *meta, u64 meta_size, |
630 | void *ctx, u64 ctx_size, bpf_ctx_copy_t ctx_copy) | |
bd570ff9 | 631 | { |
768fb61f | 632 | int nest_level = this_cpu_inc_return(bpf_event_output_nest_level); |
555c8a86 DB |
633 | struct perf_raw_frag frag = { |
634 | .copy = ctx_copy, | |
635 | .size = ctx_size, | |
636 | .data = ctx, | |
637 | }; | |
638 | struct perf_raw_record raw = { | |
639 | .frag = { | |
183fc153 AM |
640 | { |
641 | .next = ctx_size ? &frag : NULL, | |
642 | }, | |
555c8a86 DB |
643 | .size = meta_size, |
644 | .data = meta, | |
645 | }, | |
646 | }; | |
768fb61f AZ |
647 | struct perf_sample_data *sd; |
648 | struct pt_regs *regs; | |
649 | u64 ret; | |
650 | ||
651 | if (WARN_ON_ONCE(nest_level > ARRAY_SIZE(bpf_misc_sds.sds))) { | |
652 | ret = -EBUSY; | |
653 | goto out; | |
654 | } | |
655 | sd = this_cpu_ptr(&bpf_misc_sds.sds[nest_level - 1]); | |
656 | regs = this_cpu_ptr(&bpf_pt_regs.regs[nest_level - 1]); | |
bd570ff9 DB |
657 | |
658 | perf_fetch_caller_regs(regs); | |
283ca526 DB |
659 | perf_sample_data_init(sd, 0, 0); |
660 | sd->raw = &raw; | |
bd570ff9 | 661 | |
768fb61f AZ |
662 | ret = __bpf_perf_event_output(regs, map, flags, sd); |
663 | out: | |
664 | this_cpu_dec(bpf_event_output_nest_level); | |
665 | return ret; | |
bd570ff9 DB |
666 | } |
667 | ||
f3694e00 | 668 | BPF_CALL_0(bpf_get_current_task) |
606274c5 AS |
669 | { |
670 | return (long) current; | |
671 | } | |
672 | ||
673 | static const struct bpf_func_proto bpf_get_current_task_proto = { | |
674 | .func = bpf_get_current_task, | |
675 | .gpl_only = true, | |
676 | .ret_type = RET_INTEGER, | |
677 | }; | |
678 | ||
f3694e00 | 679 | BPF_CALL_2(bpf_current_task_under_cgroup, struct bpf_map *, map, u32, idx) |
60d20f91 | 680 | { |
60d20f91 SD |
681 | struct bpf_array *array = container_of(map, struct bpf_array, map); |
682 | struct cgroup *cgrp; | |
60d20f91 | 683 | |
60d20f91 SD |
684 | if (unlikely(idx >= array->map.max_entries)) |
685 | return -E2BIG; | |
686 | ||
687 | cgrp = READ_ONCE(array->ptrs[idx]); | |
688 | if (unlikely(!cgrp)) | |
689 | return -EAGAIN; | |
690 | ||
691 | return task_under_cgroup_hierarchy(current, cgrp); | |
692 | } | |
693 | ||
694 | static const struct bpf_func_proto bpf_current_task_under_cgroup_proto = { | |
695 | .func = bpf_current_task_under_cgroup, | |
696 | .gpl_only = false, | |
697 | .ret_type = RET_INTEGER, | |
698 | .arg1_type = ARG_CONST_MAP_PTR, | |
699 | .arg2_type = ARG_ANYTHING, | |
700 | }; | |
701 | ||
8b401f9e YS |
702 | struct send_signal_irq_work { |
703 | struct irq_work irq_work; | |
704 | struct task_struct *task; | |
705 | u32 sig; | |
706 | }; | |
707 | ||
708 | static DEFINE_PER_CPU(struct send_signal_irq_work, send_signal_work); | |
709 | ||
710 | static void do_bpf_send_signal(struct irq_work *entry) | |
711 | { | |
712 | struct send_signal_irq_work *work; | |
713 | ||
714 | work = container_of(entry, struct send_signal_irq_work, irq_work); | |
715 | group_send_sig_info(work->sig, SEND_SIG_PRIV, work->task, PIDTYPE_TGID); | |
716 | } | |
717 | ||
718 | BPF_CALL_1(bpf_send_signal, u32, sig) | |
719 | { | |
720 | struct send_signal_irq_work *work = NULL; | |
721 | ||
722 | /* Similar to bpf_probe_write_user, task needs to be | |
723 | * in a sound condition and kernel memory access be | |
724 | * permitted in order to send signal to the current | |
725 | * task. | |
726 | */ | |
727 | if (unlikely(current->flags & (PF_KTHREAD | PF_EXITING))) | |
728 | return -EPERM; | |
729 | if (unlikely(uaccess_kernel())) | |
730 | return -EPERM; | |
731 | if (unlikely(!nmi_uaccess_okay())) | |
732 | return -EPERM; | |
733 | ||
734 | if (in_nmi()) { | |
e1afb702 YS |
735 | /* Do an early check on signal validity. Otherwise, |
736 | * the error is lost in deferred irq_work. | |
737 | */ | |
738 | if (unlikely(!valid_signal(sig))) | |
739 | return -EINVAL; | |
740 | ||
8b401f9e | 741 | work = this_cpu_ptr(&send_signal_work); |
153bedba | 742 | if (atomic_read(&work->irq_work.flags) & IRQ_WORK_BUSY) |
8b401f9e YS |
743 | return -EBUSY; |
744 | ||
745 | /* Add the current task, which is the target of sending signal, | |
746 | * to the irq_work. The current task may change when queued | |
747 | * irq works get executed. | |
748 | */ | |
749 | work->task = current; | |
750 | work->sig = sig; | |
751 | irq_work_queue(&work->irq_work); | |
752 | return 0; | |
753 | } | |
754 | ||
755 | return group_send_sig_info(sig, SEND_SIG_PRIV, current, PIDTYPE_TGID); | |
756 | } | |
757 | ||
758 | static const struct bpf_func_proto bpf_send_signal_proto = { | |
759 | .func = bpf_send_signal, | |
760 | .gpl_only = false, | |
761 | .ret_type = RET_INTEGER, | |
762 | .arg1_type = ARG_ANYTHING, | |
763 | }; | |
764 | ||
5e43f899 AI |
765 | static const struct bpf_func_proto * |
766 | tracing_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) | |
2541517c AS |
767 | { |
768 | switch (func_id) { | |
769 | case BPF_FUNC_map_lookup_elem: | |
770 | return &bpf_map_lookup_elem_proto; | |
771 | case BPF_FUNC_map_update_elem: | |
772 | return &bpf_map_update_elem_proto; | |
773 | case BPF_FUNC_map_delete_elem: | |
774 | return &bpf_map_delete_elem_proto; | |
02a8c817 AC |
775 | case BPF_FUNC_map_push_elem: |
776 | return &bpf_map_push_elem_proto; | |
777 | case BPF_FUNC_map_pop_elem: | |
778 | return &bpf_map_pop_elem_proto; | |
779 | case BPF_FUNC_map_peek_elem: | |
780 | return &bpf_map_peek_elem_proto; | |
d9847d31 AS |
781 | case BPF_FUNC_ktime_get_ns: |
782 | return &bpf_ktime_get_ns_proto; | |
04fd61ab AS |
783 | case BPF_FUNC_tail_call: |
784 | return &bpf_tail_call_proto; | |
ffeedafb AS |
785 | case BPF_FUNC_get_current_pid_tgid: |
786 | return &bpf_get_current_pid_tgid_proto; | |
606274c5 AS |
787 | case BPF_FUNC_get_current_task: |
788 | return &bpf_get_current_task_proto; | |
ffeedafb AS |
789 | case BPF_FUNC_get_current_uid_gid: |
790 | return &bpf_get_current_uid_gid_proto; | |
791 | case BPF_FUNC_get_current_comm: | |
792 | return &bpf_get_current_comm_proto; | |
9c959c86 | 793 | case BPF_FUNC_trace_printk: |
0756ea3e | 794 | return bpf_get_trace_printk_proto(); |
ab1973d3 AS |
795 | case BPF_FUNC_get_smp_processor_id: |
796 | return &bpf_get_smp_processor_id_proto; | |
2d0e30c3 DB |
797 | case BPF_FUNC_get_numa_node_id: |
798 | return &bpf_get_numa_node_id_proto; | |
35578d79 KX |
799 | case BPF_FUNC_perf_event_read: |
800 | return &bpf_perf_event_read_proto; | |
96ae5227 SD |
801 | case BPF_FUNC_probe_write_user: |
802 | return bpf_get_probe_write_proto(); | |
60d20f91 SD |
803 | case BPF_FUNC_current_task_under_cgroup: |
804 | return &bpf_current_task_under_cgroup_proto; | |
8937bd80 AS |
805 | case BPF_FUNC_get_prandom_u32: |
806 | return &bpf_get_prandom_u32_proto; | |
6ae08ae3 DB |
807 | case BPF_FUNC_probe_read_user: |
808 | return &bpf_probe_read_user_proto; | |
809 | case BPF_FUNC_probe_read_kernel: | |
810 | return &bpf_probe_read_kernel_proto; | |
811 | case BPF_FUNC_probe_read: | |
812 | return &bpf_probe_read_compat_proto; | |
813 | case BPF_FUNC_probe_read_user_str: | |
814 | return &bpf_probe_read_user_str_proto; | |
815 | case BPF_FUNC_probe_read_kernel_str: | |
816 | return &bpf_probe_read_kernel_str_proto; | |
a5e8c070 | 817 | case BPF_FUNC_probe_read_str: |
6ae08ae3 | 818 | return &bpf_probe_read_compat_str_proto; |
34ea38ca | 819 | #ifdef CONFIG_CGROUPS |
bf6fa2c8 YS |
820 | case BPF_FUNC_get_current_cgroup_id: |
821 | return &bpf_get_current_cgroup_id_proto; | |
34ea38ca | 822 | #endif |
8b401f9e YS |
823 | case BPF_FUNC_send_signal: |
824 | return &bpf_send_signal_proto; | |
9fd82b61 AS |
825 | default: |
826 | return NULL; | |
827 | } | |
828 | } | |
829 | ||
5e43f899 AI |
830 | static const struct bpf_func_proto * |
831 | kprobe_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) | |
9fd82b61 AS |
832 | { |
833 | switch (func_id) { | |
a43eec30 AS |
834 | case BPF_FUNC_perf_event_output: |
835 | return &bpf_perf_event_output_proto; | |
d5a3b1f6 AS |
836 | case BPF_FUNC_get_stackid: |
837 | return &bpf_get_stackid_proto; | |
c195651e YS |
838 | case BPF_FUNC_get_stack: |
839 | return &bpf_get_stack_proto; | |
908432ca YS |
840 | case BPF_FUNC_perf_event_read_value: |
841 | return &bpf_perf_event_read_value_proto; | |
9802d865 JB |
842 | #ifdef CONFIG_BPF_KPROBE_OVERRIDE |
843 | case BPF_FUNC_override_return: | |
844 | return &bpf_override_return_proto; | |
845 | #endif | |
2541517c | 846 | default: |
5e43f899 | 847 | return tracing_func_proto(func_id, prog); |
2541517c AS |
848 | } |
849 | } | |
850 | ||
851 | /* bpf+kprobe programs can access fields of 'struct pt_regs' */ | |
19de99f7 | 852 | static bool kprobe_prog_is_valid_access(int off, int size, enum bpf_access_type type, |
5e43f899 | 853 | const struct bpf_prog *prog, |
23994631 | 854 | struct bpf_insn_access_aux *info) |
2541517c | 855 | { |
2541517c AS |
856 | if (off < 0 || off >= sizeof(struct pt_regs)) |
857 | return false; | |
2541517c AS |
858 | if (type != BPF_READ) |
859 | return false; | |
2541517c AS |
860 | if (off % size != 0) |
861 | return false; | |
2d071c64 DB |
862 | /* |
863 | * Assertion for 32 bit to make sure last 8 byte access | |
864 | * (BPF_DW) to the last 4 byte member is disallowed. | |
865 | */ | |
866 | if (off + size > sizeof(struct pt_regs)) | |
867 | return false; | |
868 | ||
2541517c AS |
869 | return true; |
870 | } | |
871 | ||
7de16e3a | 872 | const struct bpf_verifier_ops kprobe_verifier_ops = { |
2541517c AS |
873 | .get_func_proto = kprobe_prog_func_proto, |
874 | .is_valid_access = kprobe_prog_is_valid_access, | |
875 | }; | |
876 | ||
7de16e3a JK |
877 | const struct bpf_prog_ops kprobe_prog_ops = { |
878 | }; | |
879 | ||
f3694e00 DB |
880 | BPF_CALL_5(bpf_perf_event_output_tp, void *, tp_buff, struct bpf_map *, map, |
881 | u64, flags, void *, data, u64, size) | |
9940d67c | 882 | { |
f3694e00 DB |
883 | struct pt_regs *regs = *(struct pt_regs **)tp_buff; |
884 | ||
9940d67c AS |
885 | /* |
886 | * r1 points to perf tracepoint buffer where first 8 bytes are hidden | |
887 | * from bpf program and contain a pointer to 'struct pt_regs'. Fetch it | |
f3694e00 | 888 | * from there and call the same bpf_perf_event_output() helper inline. |
9940d67c | 889 | */ |
f3694e00 | 890 | return ____bpf_perf_event_output(regs, map, flags, data, size); |
9940d67c AS |
891 | } |
892 | ||
893 | static const struct bpf_func_proto bpf_perf_event_output_proto_tp = { | |
894 | .func = bpf_perf_event_output_tp, | |
895 | .gpl_only = true, | |
896 | .ret_type = RET_INTEGER, | |
897 | .arg1_type = ARG_PTR_TO_CTX, | |
898 | .arg2_type = ARG_CONST_MAP_PTR, | |
899 | .arg3_type = ARG_ANYTHING, | |
39f19ebb | 900 | .arg4_type = ARG_PTR_TO_MEM, |
a60dd35d | 901 | .arg5_type = ARG_CONST_SIZE_OR_ZERO, |
9940d67c AS |
902 | }; |
903 | ||
f3694e00 DB |
904 | BPF_CALL_3(bpf_get_stackid_tp, void *, tp_buff, struct bpf_map *, map, |
905 | u64, flags) | |
9940d67c | 906 | { |
f3694e00 | 907 | struct pt_regs *regs = *(struct pt_regs **)tp_buff; |
9940d67c | 908 | |
f3694e00 DB |
909 | /* |
910 | * Same comment as in bpf_perf_event_output_tp(), only that this time | |
911 | * the other helper's function body cannot be inlined due to being | |
912 | * external, thus we need to call raw helper function. | |
913 | */ | |
914 | return bpf_get_stackid((unsigned long) regs, (unsigned long) map, | |
915 | flags, 0, 0); | |
9940d67c AS |
916 | } |
917 | ||
918 | static const struct bpf_func_proto bpf_get_stackid_proto_tp = { | |
919 | .func = bpf_get_stackid_tp, | |
920 | .gpl_only = true, | |
921 | .ret_type = RET_INTEGER, | |
922 | .arg1_type = ARG_PTR_TO_CTX, | |
923 | .arg2_type = ARG_CONST_MAP_PTR, | |
924 | .arg3_type = ARG_ANYTHING, | |
925 | }; | |
926 | ||
c195651e YS |
927 | BPF_CALL_4(bpf_get_stack_tp, void *, tp_buff, void *, buf, u32, size, |
928 | u64, flags) | |
929 | { | |
930 | struct pt_regs *regs = *(struct pt_regs **)tp_buff; | |
931 | ||
932 | return bpf_get_stack((unsigned long) regs, (unsigned long) buf, | |
933 | (unsigned long) size, flags, 0); | |
934 | } | |
935 | ||
936 | static const struct bpf_func_proto bpf_get_stack_proto_tp = { | |
937 | .func = bpf_get_stack_tp, | |
938 | .gpl_only = true, | |
939 | .ret_type = RET_INTEGER, | |
940 | .arg1_type = ARG_PTR_TO_CTX, | |
941 | .arg2_type = ARG_PTR_TO_UNINIT_MEM, | |
942 | .arg3_type = ARG_CONST_SIZE_OR_ZERO, | |
943 | .arg4_type = ARG_ANYTHING, | |
944 | }; | |
945 | ||
5e43f899 AI |
946 | static const struct bpf_func_proto * |
947 | tp_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) | |
f005afed YS |
948 | { |
949 | switch (func_id) { | |
950 | case BPF_FUNC_perf_event_output: | |
951 | return &bpf_perf_event_output_proto_tp; | |
952 | case BPF_FUNC_get_stackid: | |
953 | return &bpf_get_stackid_proto_tp; | |
c195651e YS |
954 | case BPF_FUNC_get_stack: |
955 | return &bpf_get_stack_proto_tp; | |
f005afed | 956 | default: |
5e43f899 | 957 | return tracing_func_proto(func_id, prog); |
f005afed YS |
958 | } |
959 | } | |
960 | ||
961 | static bool tp_prog_is_valid_access(int off, int size, enum bpf_access_type type, | |
5e43f899 | 962 | const struct bpf_prog *prog, |
f005afed YS |
963 | struct bpf_insn_access_aux *info) |
964 | { | |
965 | if (off < sizeof(void *) || off >= PERF_MAX_TRACE_SIZE) | |
966 | return false; | |
967 | if (type != BPF_READ) | |
968 | return false; | |
969 | if (off % size != 0) | |
970 | return false; | |
971 | ||
972 | BUILD_BUG_ON(PERF_MAX_TRACE_SIZE % sizeof(__u64)); | |
973 | return true; | |
974 | } | |
975 | ||
976 | const struct bpf_verifier_ops tracepoint_verifier_ops = { | |
977 | .get_func_proto = tp_prog_func_proto, | |
978 | .is_valid_access = tp_prog_is_valid_access, | |
979 | }; | |
980 | ||
981 | const struct bpf_prog_ops tracepoint_prog_ops = { | |
982 | }; | |
983 | ||
984 | BPF_CALL_3(bpf_perf_prog_read_value, struct bpf_perf_event_data_kern *, ctx, | |
4bebdc7a YS |
985 | struct bpf_perf_event_value *, buf, u32, size) |
986 | { | |
987 | int err = -EINVAL; | |
988 | ||
989 | if (unlikely(size != sizeof(struct bpf_perf_event_value))) | |
990 | goto clear; | |
991 | err = perf_event_read_local(ctx->event, &buf->counter, &buf->enabled, | |
992 | &buf->running); | |
993 | if (unlikely(err)) | |
994 | goto clear; | |
995 | return 0; | |
996 | clear: | |
997 | memset(buf, 0, size); | |
998 | return err; | |
999 | } | |
1000 | ||
f005afed YS |
1001 | static const struct bpf_func_proto bpf_perf_prog_read_value_proto = { |
1002 | .func = bpf_perf_prog_read_value, | |
4bebdc7a YS |
1003 | .gpl_only = true, |
1004 | .ret_type = RET_INTEGER, | |
1005 | .arg1_type = ARG_PTR_TO_CTX, | |
1006 | .arg2_type = ARG_PTR_TO_UNINIT_MEM, | |
1007 | .arg3_type = ARG_CONST_SIZE, | |
1008 | }; | |
1009 | ||
5e43f899 AI |
1010 | static const struct bpf_func_proto * |
1011 | pe_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) | |
9fd82b61 AS |
1012 | { |
1013 | switch (func_id) { | |
1014 | case BPF_FUNC_perf_event_output: | |
9940d67c | 1015 | return &bpf_perf_event_output_proto_tp; |
9fd82b61 | 1016 | case BPF_FUNC_get_stackid: |
9940d67c | 1017 | return &bpf_get_stackid_proto_tp; |
c195651e YS |
1018 | case BPF_FUNC_get_stack: |
1019 | return &bpf_get_stack_proto_tp; | |
4bebdc7a | 1020 | case BPF_FUNC_perf_prog_read_value: |
f005afed | 1021 | return &bpf_perf_prog_read_value_proto; |
9fd82b61 | 1022 | default: |
5e43f899 | 1023 | return tracing_func_proto(func_id, prog); |
9fd82b61 AS |
1024 | } |
1025 | } | |
1026 | ||
c4f6699d AS |
1027 | /* |
1028 | * bpf_raw_tp_regs are separate from bpf_pt_regs used from skb/xdp | |
1029 | * to avoid potential recursive reuse issue when/if tracepoints are added | |
9594dc3c MM |
1030 | * inside bpf_*_event_output, bpf_get_stackid and/or bpf_get_stack. |
1031 | * | |
1032 | * Since raw tracepoints run despite bpf_prog_active, support concurrent usage | |
1033 | * in normal, irq, and nmi context. | |
c4f6699d | 1034 | */ |
9594dc3c MM |
1035 | struct bpf_raw_tp_regs { |
1036 | struct pt_regs regs[3]; | |
1037 | }; | |
1038 | static DEFINE_PER_CPU(struct bpf_raw_tp_regs, bpf_raw_tp_regs); | |
1039 | static DEFINE_PER_CPU(int, bpf_raw_tp_nest_level); | |
1040 | static struct pt_regs *get_bpf_raw_tp_regs(void) | |
1041 | { | |
1042 | struct bpf_raw_tp_regs *tp_regs = this_cpu_ptr(&bpf_raw_tp_regs); | |
1043 | int nest_level = this_cpu_inc_return(bpf_raw_tp_nest_level); | |
1044 | ||
1045 | if (WARN_ON_ONCE(nest_level > ARRAY_SIZE(tp_regs->regs))) { | |
1046 | this_cpu_dec(bpf_raw_tp_nest_level); | |
1047 | return ERR_PTR(-EBUSY); | |
1048 | } | |
1049 | ||
1050 | return &tp_regs->regs[nest_level - 1]; | |
1051 | } | |
1052 | ||
1053 | static void put_bpf_raw_tp_regs(void) | |
1054 | { | |
1055 | this_cpu_dec(bpf_raw_tp_nest_level); | |
1056 | } | |
1057 | ||
c4f6699d AS |
1058 | BPF_CALL_5(bpf_perf_event_output_raw_tp, struct bpf_raw_tracepoint_args *, args, |
1059 | struct bpf_map *, map, u64, flags, void *, data, u64, size) | |
1060 | { | |
9594dc3c MM |
1061 | struct pt_regs *regs = get_bpf_raw_tp_regs(); |
1062 | int ret; | |
1063 | ||
1064 | if (IS_ERR(regs)) | |
1065 | return PTR_ERR(regs); | |
c4f6699d AS |
1066 | |
1067 | perf_fetch_caller_regs(regs); | |
9594dc3c MM |
1068 | ret = ____bpf_perf_event_output(regs, map, flags, data, size); |
1069 | ||
1070 | put_bpf_raw_tp_regs(); | |
1071 | return ret; | |
c4f6699d AS |
1072 | } |
1073 | ||
1074 | static const struct bpf_func_proto bpf_perf_event_output_proto_raw_tp = { | |
1075 | .func = bpf_perf_event_output_raw_tp, | |
1076 | .gpl_only = true, | |
1077 | .ret_type = RET_INTEGER, | |
1078 | .arg1_type = ARG_PTR_TO_CTX, | |
1079 | .arg2_type = ARG_CONST_MAP_PTR, | |
1080 | .arg3_type = ARG_ANYTHING, | |
1081 | .arg4_type = ARG_PTR_TO_MEM, | |
1082 | .arg5_type = ARG_CONST_SIZE_OR_ZERO, | |
1083 | }; | |
1084 | ||
a7658e1a AS |
1085 | extern const struct bpf_func_proto bpf_skb_output_proto; |
1086 | ||
c4f6699d AS |
1087 | BPF_CALL_3(bpf_get_stackid_raw_tp, struct bpf_raw_tracepoint_args *, args, |
1088 | struct bpf_map *, map, u64, flags) | |
1089 | { | |
9594dc3c MM |
1090 | struct pt_regs *regs = get_bpf_raw_tp_regs(); |
1091 | int ret; | |
1092 | ||
1093 | if (IS_ERR(regs)) | |
1094 | return PTR_ERR(regs); | |
c4f6699d AS |
1095 | |
1096 | perf_fetch_caller_regs(regs); | |
1097 | /* similar to bpf_perf_event_output_tp, but pt_regs fetched differently */ | |
9594dc3c MM |
1098 | ret = bpf_get_stackid((unsigned long) regs, (unsigned long) map, |
1099 | flags, 0, 0); | |
1100 | put_bpf_raw_tp_regs(); | |
1101 | return ret; | |
c4f6699d AS |
1102 | } |
1103 | ||
1104 | static const struct bpf_func_proto bpf_get_stackid_proto_raw_tp = { | |
1105 | .func = bpf_get_stackid_raw_tp, | |
1106 | .gpl_only = true, | |
1107 | .ret_type = RET_INTEGER, | |
1108 | .arg1_type = ARG_PTR_TO_CTX, | |
1109 | .arg2_type = ARG_CONST_MAP_PTR, | |
1110 | .arg3_type = ARG_ANYTHING, | |
1111 | }; | |
1112 | ||
c195651e YS |
1113 | BPF_CALL_4(bpf_get_stack_raw_tp, struct bpf_raw_tracepoint_args *, args, |
1114 | void *, buf, u32, size, u64, flags) | |
1115 | { | |
9594dc3c MM |
1116 | struct pt_regs *regs = get_bpf_raw_tp_regs(); |
1117 | int ret; | |
1118 | ||
1119 | if (IS_ERR(regs)) | |
1120 | return PTR_ERR(regs); | |
c195651e YS |
1121 | |
1122 | perf_fetch_caller_regs(regs); | |
9594dc3c MM |
1123 | ret = bpf_get_stack((unsigned long) regs, (unsigned long) buf, |
1124 | (unsigned long) size, flags, 0); | |
1125 | put_bpf_raw_tp_regs(); | |
1126 | return ret; | |
c195651e YS |
1127 | } |
1128 | ||
1129 | static const struct bpf_func_proto bpf_get_stack_proto_raw_tp = { | |
1130 | .func = bpf_get_stack_raw_tp, | |
1131 | .gpl_only = true, | |
1132 | .ret_type = RET_INTEGER, | |
1133 | .arg1_type = ARG_PTR_TO_CTX, | |
1134 | .arg2_type = ARG_PTR_TO_MEM, | |
1135 | .arg3_type = ARG_CONST_SIZE_OR_ZERO, | |
1136 | .arg4_type = ARG_ANYTHING, | |
1137 | }; | |
1138 | ||
5e43f899 AI |
1139 | static const struct bpf_func_proto * |
1140 | raw_tp_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) | |
c4f6699d AS |
1141 | { |
1142 | switch (func_id) { | |
1143 | case BPF_FUNC_perf_event_output: | |
1144 | return &bpf_perf_event_output_proto_raw_tp; | |
1145 | case BPF_FUNC_get_stackid: | |
1146 | return &bpf_get_stackid_proto_raw_tp; | |
c195651e YS |
1147 | case BPF_FUNC_get_stack: |
1148 | return &bpf_get_stack_proto_raw_tp; | |
c4f6699d | 1149 | default: |
5e43f899 | 1150 | return tracing_func_proto(func_id, prog); |
c4f6699d AS |
1151 | } |
1152 | } | |
1153 | ||
f1b9509c AS |
1154 | static const struct bpf_func_proto * |
1155 | tracing_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) | |
1156 | { | |
1157 | switch (func_id) { | |
1158 | #ifdef CONFIG_NET | |
1159 | case BPF_FUNC_skb_output: | |
1160 | return &bpf_skb_output_proto; | |
1161 | #endif | |
1162 | default: | |
1163 | return raw_tp_prog_func_proto(func_id, prog); | |
1164 | } | |
1165 | } | |
1166 | ||
c4f6699d AS |
1167 | static bool raw_tp_prog_is_valid_access(int off, int size, |
1168 | enum bpf_access_type type, | |
5e43f899 | 1169 | const struct bpf_prog *prog, |
c4f6699d AS |
1170 | struct bpf_insn_access_aux *info) |
1171 | { | |
f1b9509c AS |
1172 | if (off < 0 || off >= sizeof(__u64) * MAX_BPF_FUNC_ARGS) |
1173 | return false; | |
1174 | if (type != BPF_READ) | |
1175 | return false; | |
1176 | if (off % size != 0) | |
1177 | return false; | |
1178 | return true; | |
1179 | } | |
1180 | ||
1181 | static bool tracing_prog_is_valid_access(int off, int size, | |
1182 | enum bpf_access_type type, | |
1183 | const struct bpf_prog *prog, | |
1184 | struct bpf_insn_access_aux *info) | |
1185 | { | |
1186 | if (off < 0 || off >= sizeof(__u64) * MAX_BPF_FUNC_ARGS) | |
c4f6699d AS |
1187 | return false; |
1188 | if (type != BPF_READ) | |
1189 | return false; | |
1190 | if (off % size != 0) | |
1191 | return false; | |
9e15db66 | 1192 | return btf_ctx_access(off, size, type, prog, info); |
c4f6699d AS |
1193 | } |
1194 | ||
1195 | const struct bpf_verifier_ops raw_tracepoint_verifier_ops = { | |
1196 | .get_func_proto = raw_tp_prog_func_proto, | |
1197 | .is_valid_access = raw_tp_prog_is_valid_access, | |
1198 | }; | |
1199 | ||
1200 | const struct bpf_prog_ops raw_tracepoint_prog_ops = { | |
1201 | }; | |
1202 | ||
f1b9509c AS |
1203 | const struct bpf_verifier_ops tracing_verifier_ops = { |
1204 | .get_func_proto = tracing_prog_func_proto, | |
1205 | .is_valid_access = tracing_prog_is_valid_access, | |
1206 | }; | |
1207 | ||
1208 | const struct bpf_prog_ops tracing_prog_ops = { | |
1209 | }; | |
1210 | ||
9df1c28b MM |
1211 | static bool raw_tp_writable_prog_is_valid_access(int off, int size, |
1212 | enum bpf_access_type type, | |
1213 | const struct bpf_prog *prog, | |
1214 | struct bpf_insn_access_aux *info) | |
1215 | { | |
1216 | if (off == 0) { | |
1217 | if (size != sizeof(u64) || type != BPF_READ) | |
1218 | return false; | |
1219 | info->reg_type = PTR_TO_TP_BUFFER; | |
1220 | } | |
1221 | return raw_tp_prog_is_valid_access(off, size, type, prog, info); | |
1222 | } | |
1223 | ||
1224 | const struct bpf_verifier_ops raw_tracepoint_writable_verifier_ops = { | |
1225 | .get_func_proto = raw_tp_prog_func_proto, | |
1226 | .is_valid_access = raw_tp_writable_prog_is_valid_access, | |
1227 | }; | |
1228 | ||
1229 | const struct bpf_prog_ops raw_tracepoint_writable_prog_ops = { | |
1230 | }; | |
1231 | ||
0515e599 | 1232 | static bool pe_prog_is_valid_access(int off, int size, enum bpf_access_type type, |
5e43f899 | 1233 | const struct bpf_prog *prog, |
23994631 | 1234 | struct bpf_insn_access_aux *info) |
0515e599 | 1235 | { |
95da0cdb | 1236 | const int size_u64 = sizeof(u64); |
31fd8581 | 1237 | |
0515e599 AS |
1238 | if (off < 0 || off >= sizeof(struct bpf_perf_event_data)) |
1239 | return false; | |
1240 | if (type != BPF_READ) | |
1241 | return false; | |
bc23105c DB |
1242 | if (off % size != 0) { |
1243 | if (sizeof(unsigned long) != 4) | |
1244 | return false; | |
1245 | if (size != 8) | |
1246 | return false; | |
1247 | if (off % size != 4) | |
1248 | return false; | |
1249 | } | |
31fd8581 | 1250 | |
f96da094 DB |
1251 | switch (off) { |
1252 | case bpf_ctx_range(struct bpf_perf_event_data, sample_period): | |
95da0cdb TQ |
1253 | bpf_ctx_record_field_size(info, size_u64); |
1254 | if (!bpf_ctx_narrow_access_ok(off, size, size_u64)) | |
1255 | return false; | |
1256 | break; | |
1257 | case bpf_ctx_range(struct bpf_perf_event_data, addr): | |
1258 | bpf_ctx_record_field_size(info, size_u64); | |
1259 | if (!bpf_ctx_narrow_access_ok(off, size, size_u64)) | |
23994631 | 1260 | return false; |
f96da094 DB |
1261 | break; |
1262 | default: | |
0515e599 AS |
1263 | if (size != sizeof(long)) |
1264 | return false; | |
1265 | } | |
f96da094 | 1266 | |
0515e599 AS |
1267 | return true; |
1268 | } | |
1269 | ||
6b8cc1d1 DB |
1270 | static u32 pe_prog_convert_ctx_access(enum bpf_access_type type, |
1271 | const struct bpf_insn *si, | |
0515e599 | 1272 | struct bpf_insn *insn_buf, |
f96da094 | 1273 | struct bpf_prog *prog, u32 *target_size) |
0515e599 AS |
1274 | { |
1275 | struct bpf_insn *insn = insn_buf; | |
1276 | ||
6b8cc1d1 | 1277 | switch (si->off) { |
0515e599 | 1278 | case offsetof(struct bpf_perf_event_data, sample_period): |
f035a515 | 1279 | *insn++ = BPF_LDX_MEM(BPF_FIELD_SIZEOF(struct bpf_perf_event_data_kern, |
6b8cc1d1 | 1280 | data), si->dst_reg, si->src_reg, |
0515e599 | 1281 | offsetof(struct bpf_perf_event_data_kern, data)); |
6b8cc1d1 | 1282 | *insn++ = BPF_LDX_MEM(BPF_DW, si->dst_reg, si->dst_reg, |
f96da094 DB |
1283 | bpf_target_off(struct perf_sample_data, period, 8, |
1284 | target_size)); | |
0515e599 | 1285 | break; |
95da0cdb TQ |
1286 | case offsetof(struct bpf_perf_event_data, addr): |
1287 | *insn++ = BPF_LDX_MEM(BPF_FIELD_SIZEOF(struct bpf_perf_event_data_kern, | |
1288 | data), si->dst_reg, si->src_reg, | |
1289 | offsetof(struct bpf_perf_event_data_kern, data)); | |
1290 | *insn++ = BPF_LDX_MEM(BPF_DW, si->dst_reg, si->dst_reg, | |
1291 | bpf_target_off(struct perf_sample_data, addr, 8, | |
1292 | target_size)); | |
1293 | break; | |
0515e599 | 1294 | default: |
f035a515 | 1295 | *insn++ = BPF_LDX_MEM(BPF_FIELD_SIZEOF(struct bpf_perf_event_data_kern, |
6b8cc1d1 | 1296 | regs), si->dst_reg, si->src_reg, |
0515e599 | 1297 | offsetof(struct bpf_perf_event_data_kern, regs)); |
6b8cc1d1 DB |
1298 | *insn++ = BPF_LDX_MEM(BPF_SIZEOF(long), si->dst_reg, si->dst_reg, |
1299 | si->off); | |
0515e599 AS |
1300 | break; |
1301 | } | |
1302 | ||
1303 | return insn - insn_buf; | |
1304 | } | |
1305 | ||
7de16e3a | 1306 | const struct bpf_verifier_ops perf_event_verifier_ops = { |
f005afed | 1307 | .get_func_proto = pe_prog_func_proto, |
0515e599 AS |
1308 | .is_valid_access = pe_prog_is_valid_access, |
1309 | .convert_ctx_access = pe_prog_convert_ctx_access, | |
1310 | }; | |
7de16e3a JK |
1311 | |
1312 | const struct bpf_prog_ops perf_event_prog_ops = { | |
1313 | }; | |
e87c6bc3 YS |
1314 | |
1315 | static DEFINE_MUTEX(bpf_event_mutex); | |
1316 | ||
c8c088ba YS |
1317 | #define BPF_TRACE_MAX_PROGS 64 |
1318 | ||
e87c6bc3 YS |
1319 | int perf_event_attach_bpf_prog(struct perf_event *event, |
1320 | struct bpf_prog *prog) | |
1321 | { | |
e672db03 | 1322 | struct bpf_prog_array *old_array; |
e87c6bc3 YS |
1323 | struct bpf_prog_array *new_array; |
1324 | int ret = -EEXIST; | |
1325 | ||
9802d865 | 1326 | /* |
b4da3340 MH |
1327 | * Kprobe override only works if they are on the function entry, |
1328 | * and only if they are on the opt-in list. | |
9802d865 JB |
1329 | */ |
1330 | if (prog->kprobe_override && | |
b4da3340 | 1331 | (!trace_kprobe_on_func_entry(event->tp_event) || |
9802d865 JB |
1332 | !trace_kprobe_error_injectable(event->tp_event))) |
1333 | return -EINVAL; | |
1334 | ||
e87c6bc3 YS |
1335 | mutex_lock(&bpf_event_mutex); |
1336 | ||
1337 | if (event->prog) | |
07c41a29 | 1338 | goto unlock; |
e87c6bc3 | 1339 | |
e672db03 | 1340 | old_array = bpf_event_rcu_dereference(event->tp_event->prog_array); |
c8c088ba YS |
1341 | if (old_array && |
1342 | bpf_prog_array_length(old_array) >= BPF_TRACE_MAX_PROGS) { | |
1343 | ret = -E2BIG; | |
1344 | goto unlock; | |
1345 | } | |
1346 | ||
e87c6bc3 YS |
1347 | ret = bpf_prog_array_copy(old_array, NULL, prog, &new_array); |
1348 | if (ret < 0) | |
07c41a29 | 1349 | goto unlock; |
e87c6bc3 YS |
1350 | |
1351 | /* set the new array to event->tp_event and set event->prog */ | |
1352 | event->prog = prog; | |
1353 | rcu_assign_pointer(event->tp_event->prog_array, new_array); | |
1354 | bpf_prog_array_free(old_array); | |
1355 | ||
07c41a29 | 1356 | unlock: |
e87c6bc3 YS |
1357 | mutex_unlock(&bpf_event_mutex); |
1358 | return ret; | |
1359 | } | |
1360 | ||
1361 | void perf_event_detach_bpf_prog(struct perf_event *event) | |
1362 | { | |
e672db03 | 1363 | struct bpf_prog_array *old_array; |
e87c6bc3 YS |
1364 | struct bpf_prog_array *new_array; |
1365 | int ret; | |
1366 | ||
1367 | mutex_lock(&bpf_event_mutex); | |
1368 | ||
1369 | if (!event->prog) | |
07c41a29 | 1370 | goto unlock; |
e87c6bc3 | 1371 | |
e672db03 | 1372 | old_array = bpf_event_rcu_dereference(event->tp_event->prog_array); |
e87c6bc3 | 1373 | ret = bpf_prog_array_copy(old_array, event->prog, NULL, &new_array); |
170a7e3e SY |
1374 | if (ret == -ENOENT) |
1375 | goto unlock; | |
e87c6bc3 YS |
1376 | if (ret < 0) { |
1377 | bpf_prog_array_delete_safe(old_array, event->prog); | |
1378 | } else { | |
1379 | rcu_assign_pointer(event->tp_event->prog_array, new_array); | |
1380 | bpf_prog_array_free(old_array); | |
1381 | } | |
1382 | ||
1383 | bpf_prog_put(event->prog); | |
1384 | event->prog = NULL; | |
1385 | ||
07c41a29 | 1386 | unlock: |
e87c6bc3 YS |
1387 | mutex_unlock(&bpf_event_mutex); |
1388 | } | |
f371b304 | 1389 | |
f4e2298e | 1390 | int perf_event_query_prog_array(struct perf_event *event, void __user *info) |
f371b304 YS |
1391 | { |
1392 | struct perf_event_query_bpf __user *uquery = info; | |
1393 | struct perf_event_query_bpf query = {}; | |
e672db03 | 1394 | struct bpf_prog_array *progs; |
3a38bb98 | 1395 | u32 *ids, prog_cnt, ids_len; |
f371b304 YS |
1396 | int ret; |
1397 | ||
1398 | if (!capable(CAP_SYS_ADMIN)) | |
1399 | return -EPERM; | |
1400 | if (event->attr.type != PERF_TYPE_TRACEPOINT) | |
1401 | return -EINVAL; | |
1402 | if (copy_from_user(&query, uquery, sizeof(query))) | |
1403 | return -EFAULT; | |
3a38bb98 YS |
1404 | |
1405 | ids_len = query.ids_len; | |
1406 | if (ids_len > BPF_TRACE_MAX_PROGS) | |
9c481b90 | 1407 | return -E2BIG; |
3a38bb98 YS |
1408 | ids = kcalloc(ids_len, sizeof(u32), GFP_USER | __GFP_NOWARN); |
1409 | if (!ids) | |
1410 | return -ENOMEM; | |
1411 | /* | |
1412 | * The above kcalloc returns ZERO_SIZE_PTR when ids_len = 0, which | |
1413 | * is required when user only wants to check for uquery->prog_cnt. | |
1414 | * There is no need to check for it since the case is handled | |
1415 | * gracefully in bpf_prog_array_copy_info. | |
1416 | */ | |
f371b304 YS |
1417 | |
1418 | mutex_lock(&bpf_event_mutex); | |
e672db03 SF |
1419 | progs = bpf_event_rcu_dereference(event->tp_event->prog_array); |
1420 | ret = bpf_prog_array_copy_info(progs, ids, ids_len, &prog_cnt); | |
f371b304 YS |
1421 | mutex_unlock(&bpf_event_mutex); |
1422 | ||
3a38bb98 YS |
1423 | if (copy_to_user(&uquery->prog_cnt, &prog_cnt, sizeof(prog_cnt)) || |
1424 | copy_to_user(uquery->ids, ids, ids_len * sizeof(u32))) | |
1425 | ret = -EFAULT; | |
1426 | ||
1427 | kfree(ids); | |
f371b304 YS |
1428 | return ret; |
1429 | } | |
c4f6699d AS |
1430 | |
1431 | extern struct bpf_raw_event_map __start__bpf_raw_tp[]; | |
1432 | extern struct bpf_raw_event_map __stop__bpf_raw_tp[]; | |
1433 | ||
a38d1107 | 1434 | struct bpf_raw_event_map *bpf_get_raw_tracepoint(const char *name) |
c4f6699d AS |
1435 | { |
1436 | struct bpf_raw_event_map *btp = __start__bpf_raw_tp; | |
1437 | ||
1438 | for (; btp < __stop__bpf_raw_tp; btp++) { | |
1439 | if (!strcmp(btp->tp->name, name)) | |
1440 | return btp; | |
1441 | } | |
a38d1107 MM |
1442 | |
1443 | return bpf_get_raw_tracepoint_module(name); | |
1444 | } | |
1445 | ||
1446 | void bpf_put_raw_tracepoint(struct bpf_raw_event_map *btp) | |
1447 | { | |
1448 | struct module *mod = __module_address((unsigned long)btp); | |
1449 | ||
1450 | if (mod) | |
1451 | module_put(mod); | |
c4f6699d AS |
1452 | } |
1453 | ||
1454 | static __always_inline | |
1455 | void __bpf_trace_run(struct bpf_prog *prog, u64 *args) | |
1456 | { | |
1457 | rcu_read_lock(); | |
1458 | preempt_disable(); | |
1459 | (void) BPF_PROG_RUN(prog, args); | |
1460 | preempt_enable(); | |
1461 | rcu_read_unlock(); | |
1462 | } | |
1463 | ||
1464 | #define UNPACK(...) __VA_ARGS__ | |
1465 | #define REPEAT_1(FN, DL, X, ...) FN(X) | |
1466 | #define REPEAT_2(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_1(FN, DL, __VA_ARGS__) | |
1467 | #define REPEAT_3(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_2(FN, DL, __VA_ARGS__) | |
1468 | #define REPEAT_4(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_3(FN, DL, __VA_ARGS__) | |
1469 | #define REPEAT_5(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_4(FN, DL, __VA_ARGS__) | |
1470 | #define REPEAT_6(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_5(FN, DL, __VA_ARGS__) | |
1471 | #define REPEAT_7(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_6(FN, DL, __VA_ARGS__) | |
1472 | #define REPEAT_8(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_7(FN, DL, __VA_ARGS__) | |
1473 | #define REPEAT_9(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_8(FN, DL, __VA_ARGS__) | |
1474 | #define REPEAT_10(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_9(FN, DL, __VA_ARGS__) | |
1475 | #define REPEAT_11(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_10(FN, DL, __VA_ARGS__) | |
1476 | #define REPEAT_12(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_11(FN, DL, __VA_ARGS__) | |
1477 | #define REPEAT(X, FN, DL, ...) REPEAT_##X(FN, DL, __VA_ARGS__) | |
1478 | ||
1479 | #define SARG(X) u64 arg##X | |
1480 | #define COPY(X) args[X] = arg##X | |
1481 | ||
1482 | #define __DL_COM (,) | |
1483 | #define __DL_SEM (;) | |
1484 | ||
1485 | #define __SEQ_0_11 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11 | |
1486 | ||
1487 | #define BPF_TRACE_DEFN_x(x) \ | |
1488 | void bpf_trace_run##x(struct bpf_prog *prog, \ | |
1489 | REPEAT(x, SARG, __DL_COM, __SEQ_0_11)) \ | |
1490 | { \ | |
1491 | u64 args[x]; \ | |
1492 | REPEAT(x, COPY, __DL_SEM, __SEQ_0_11); \ | |
1493 | __bpf_trace_run(prog, args); \ | |
1494 | } \ | |
1495 | EXPORT_SYMBOL_GPL(bpf_trace_run##x) | |
1496 | BPF_TRACE_DEFN_x(1); | |
1497 | BPF_TRACE_DEFN_x(2); | |
1498 | BPF_TRACE_DEFN_x(3); | |
1499 | BPF_TRACE_DEFN_x(4); | |
1500 | BPF_TRACE_DEFN_x(5); | |
1501 | BPF_TRACE_DEFN_x(6); | |
1502 | BPF_TRACE_DEFN_x(7); | |
1503 | BPF_TRACE_DEFN_x(8); | |
1504 | BPF_TRACE_DEFN_x(9); | |
1505 | BPF_TRACE_DEFN_x(10); | |
1506 | BPF_TRACE_DEFN_x(11); | |
1507 | BPF_TRACE_DEFN_x(12); | |
1508 | ||
1509 | static int __bpf_probe_register(struct bpf_raw_event_map *btp, struct bpf_prog *prog) | |
1510 | { | |
1511 | struct tracepoint *tp = btp->tp; | |
1512 | ||
1513 | /* | |
1514 | * check that program doesn't access arguments beyond what's | |
1515 | * available in this tracepoint | |
1516 | */ | |
1517 | if (prog->aux->max_ctx_offset > btp->num_args * sizeof(u64)) | |
1518 | return -EINVAL; | |
1519 | ||
9df1c28b MM |
1520 | if (prog->aux->max_tp_access > btp->writable_size) |
1521 | return -EINVAL; | |
1522 | ||
c4f6699d AS |
1523 | return tracepoint_probe_register(tp, (void *)btp->bpf_func, prog); |
1524 | } | |
1525 | ||
1526 | int bpf_probe_register(struct bpf_raw_event_map *btp, struct bpf_prog *prog) | |
1527 | { | |
e16ec340 | 1528 | return __bpf_probe_register(btp, prog); |
c4f6699d AS |
1529 | } |
1530 | ||
1531 | int bpf_probe_unregister(struct bpf_raw_event_map *btp, struct bpf_prog *prog) | |
1532 | { | |
e16ec340 | 1533 | return tracepoint_probe_unregister(btp->tp, (void *)btp->bpf_func, prog); |
c4f6699d | 1534 | } |
41bdc4b4 YS |
1535 | |
1536 | int bpf_get_perf_event_info(const struct perf_event *event, u32 *prog_id, | |
1537 | u32 *fd_type, const char **buf, | |
1538 | u64 *probe_offset, u64 *probe_addr) | |
1539 | { | |
1540 | bool is_tracepoint, is_syscall_tp; | |
1541 | struct bpf_prog *prog; | |
1542 | int flags, err = 0; | |
1543 | ||
1544 | prog = event->prog; | |
1545 | if (!prog) | |
1546 | return -ENOENT; | |
1547 | ||
1548 | /* not supporting BPF_PROG_TYPE_PERF_EVENT yet */ | |
1549 | if (prog->type == BPF_PROG_TYPE_PERF_EVENT) | |
1550 | return -EOPNOTSUPP; | |
1551 | ||
1552 | *prog_id = prog->aux->id; | |
1553 | flags = event->tp_event->flags; | |
1554 | is_tracepoint = flags & TRACE_EVENT_FL_TRACEPOINT; | |
1555 | is_syscall_tp = is_syscall_trace_event(event->tp_event); | |
1556 | ||
1557 | if (is_tracepoint || is_syscall_tp) { | |
1558 | *buf = is_tracepoint ? event->tp_event->tp->name | |
1559 | : event->tp_event->name; | |
1560 | *fd_type = BPF_FD_TYPE_TRACEPOINT; | |
1561 | *probe_offset = 0x0; | |
1562 | *probe_addr = 0x0; | |
1563 | } else { | |
1564 | /* kprobe/uprobe */ | |
1565 | err = -EOPNOTSUPP; | |
1566 | #ifdef CONFIG_KPROBE_EVENTS | |
1567 | if (flags & TRACE_EVENT_FL_KPROBE) | |
1568 | err = bpf_get_kprobe_info(event, fd_type, buf, | |
1569 | probe_offset, probe_addr, | |
1570 | event->attr.type == PERF_TYPE_TRACEPOINT); | |
1571 | #endif | |
1572 | #ifdef CONFIG_UPROBE_EVENTS | |
1573 | if (flags & TRACE_EVENT_FL_UPROBE) | |
1574 | err = bpf_get_uprobe_info(event, fd_type, buf, | |
1575 | probe_offset, | |
1576 | event->attr.type == PERF_TYPE_TRACEPOINT); | |
1577 | #endif | |
1578 | } | |
1579 | ||
1580 | return err; | |
1581 | } | |
a38d1107 | 1582 | |
9db1ff0a YS |
1583 | static int __init send_signal_irq_work_init(void) |
1584 | { | |
1585 | int cpu; | |
1586 | struct send_signal_irq_work *work; | |
1587 | ||
1588 | for_each_possible_cpu(cpu) { | |
1589 | work = per_cpu_ptr(&send_signal_work, cpu); | |
1590 | init_irq_work(&work->irq_work, do_bpf_send_signal); | |
1591 | } | |
1592 | return 0; | |
1593 | } | |
1594 | ||
1595 | subsys_initcall(send_signal_irq_work_init); | |
1596 | ||
a38d1107 | 1597 | #ifdef CONFIG_MODULES |
390e99cf SF |
1598 | static int bpf_event_notify(struct notifier_block *nb, unsigned long op, |
1599 | void *module) | |
a38d1107 MM |
1600 | { |
1601 | struct bpf_trace_module *btm, *tmp; | |
1602 | struct module *mod = module; | |
1603 | ||
1604 | if (mod->num_bpf_raw_events == 0 || | |
1605 | (op != MODULE_STATE_COMING && op != MODULE_STATE_GOING)) | |
1606 | return 0; | |
1607 | ||
1608 | mutex_lock(&bpf_module_mutex); | |
1609 | ||
1610 | switch (op) { | |
1611 | case MODULE_STATE_COMING: | |
1612 | btm = kzalloc(sizeof(*btm), GFP_KERNEL); | |
1613 | if (btm) { | |
1614 | btm->module = module; | |
1615 | list_add(&btm->list, &bpf_trace_modules); | |
1616 | } | |
1617 | break; | |
1618 | case MODULE_STATE_GOING: | |
1619 | list_for_each_entry_safe(btm, tmp, &bpf_trace_modules, list) { | |
1620 | if (btm->module == module) { | |
1621 | list_del(&btm->list); | |
1622 | kfree(btm); | |
1623 | break; | |
1624 | } | |
1625 | } | |
1626 | break; | |
1627 | } | |
1628 | ||
1629 | mutex_unlock(&bpf_module_mutex); | |
1630 | ||
1631 | return 0; | |
1632 | } | |
1633 | ||
1634 | static struct notifier_block bpf_module_nb = { | |
1635 | .notifier_call = bpf_event_notify, | |
1636 | }; | |
1637 | ||
390e99cf | 1638 | static int __init bpf_event_init(void) |
a38d1107 MM |
1639 | { |
1640 | register_module_notifier(&bpf_module_nb); | |
1641 | return 0; | |
1642 | } | |
1643 | ||
1644 | fs_initcall(bpf_event_init); | |
1645 | #endif /* CONFIG_MODULES */ |