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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; | |
8482941f | 706 | enum pid_type type; |
8b401f9e YS |
707 | }; |
708 | ||
709 | static DEFINE_PER_CPU(struct send_signal_irq_work, send_signal_work); | |
710 | ||
711 | static void do_bpf_send_signal(struct irq_work *entry) | |
712 | { | |
713 | struct send_signal_irq_work *work; | |
714 | ||
715 | work = container_of(entry, struct send_signal_irq_work, irq_work); | |
8482941f | 716 | group_send_sig_info(work->sig, SEND_SIG_PRIV, work->task, work->type); |
8b401f9e YS |
717 | } |
718 | ||
8482941f | 719 | static int bpf_send_signal_common(u32 sig, enum pid_type type) |
8b401f9e YS |
720 | { |
721 | struct send_signal_irq_work *work = NULL; | |
722 | ||
723 | /* Similar to bpf_probe_write_user, task needs to be | |
724 | * in a sound condition and kernel memory access be | |
725 | * permitted in order to send signal to the current | |
726 | * task. | |
727 | */ | |
728 | if (unlikely(current->flags & (PF_KTHREAD | PF_EXITING))) | |
729 | return -EPERM; | |
730 | if (unlikely(uaccess_kernel())) | |
731 | return -EPERM; | |
732 | if (unlikely(!nmi_uaccess_okay())) | |
733 | return -EPERM; | |
734 | ||
735 | if (in_nmi()) { | |
e1afb702 YS |
736 | /* Do an early check on signal validity. Otherwise, |
737 | * the error is lost in deferred irq_work. | |
738 | */ | |
739 | if (unlikely(!valid_signal(sig))) | |
740 | return -EINVAL; | |
741 | ||
8b401f9e | 742 | work = this_cpu_ptr(&send_signal_work); |
153bedba | 743 | if (atomic_read(&work->irq_work.flags) & IRQ_WORK_BUSY) |
8b401f9e YS |
744 | return -EBUSY; |
745 | ||
746 | /* Add the current task, which is the target of sending signal, | |
747 | * to the irq_work. The current task may change when queued | |
748 | * irq works get executed. | |
749 | */ | |
750 | work->task = current; | |
751 | work->sig = sig; | |
8482941f | 752 | work->type = type; |
8b401f9e YS |
753 | irq_work_queue(&work->irq_work); |
754 | return 0; | |
755 | } | |
756 | ||
8482941f YS |
757 | return group_send_sig_info(sig, SEND_SIG_PRIV, current, type); |
758 | } | |
759 | ||
760 | BPF_CALL_1(bpf_send_signal, u32, sig) | |
761 | { | |
762 | return bpf_send_signal_common(sig, PIDTYPE_TGID); | |
8b401f9e YS |
763 | } |
764 | ||
765 | static const struct bpf_func_proto bpf_send_signal_proto = { | |
766 | .func = bpf_send_signal, | |
767 | .gpl_only = false, | |
768 | .ret_type = RET_INTEGER, | |
769 | .arg1_type = ARG_ANYTHING, | |
770 | }; | |
771 | ||
8482941f YS |
772 | BPF_CALL_1(bpf_send_signal_thread, u32, sig) |
773 | { | |
774 | return bpf_send_signal_common(sig, PIDTYPE_PID); | |
775 | } | |
776 | ||
777 | static const struct bpf_func_proto bpf_send_signal_thread_proto = { | |
778 | .func = bpf_send_signal_thread, | |
779 | .gpl_only = false, | |
780 | .ret_type = RET_INTEGER, | |
781 | .arg1_type = ARG_ANYTHING, | |
782 | }; | |
783 | ||
5e43f899 AI |
784 | static const struct bpf_func_proto * |
785 | tracing_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) | |
2541517c AS |
786 | { |
787 | switch (func_id) { | |
788 | case BPF_FUNC_map_lookup_elem: | |
789 | return &bpf_map_lookup_elem_proto; | |
790 | case BPF_FUNC_map_update_elem: | |
791 | return &bpf_map_update_elem_proto; | |
792 | case BPF_FUNC_map_delete_elem: | |
793 | return &bpf_map_delete_elem_proto; | |
02a8c817 AC |
794 | case BPF_FUNC_map_push_elem: |
795 | return &bpf_map_push_elem_proto; | |
796 | case BPF_FUNC_map_pop_elem: | |
797 | return &bpf_map_pop_elem_proto; | |
798 | case BPF_FUNC_map_peek_elem: | |
799 | return &bpf_map_peek_elem_proto; | |
d9847d31 AS |
800 | case BPF_FUNC_ktime_get_ns: |
801 | return &bpf_ktime_get_ns_proto; | |
04fd61ab AS |
802 | case BPF_FUNC_tail_call: |
803 | return &bpf_tail_call_proto; | |
ffeedafb AS |
804 | case BPF_FUNC_get_current_pid_tgid: |
805 | return &bpf_get_current_pid_tgid_proto; | |
606274c5 AS |
806 | case BPF_FUNC_get_current_task: |
807 | return &bpf_get_current_task_proto; | |
ffeedafb AS |
808 | case BPF_FUNC_get_current_uid_gid: |
809 | return &bpf_get_current_uid_gid_proto; | |
810 | case BPF_FUNC_get_current_comm: | |
811 | return &bpf_get_current_comm_proto; | |
9c959c86 | 812 | case BPF_FUNC_trace_printk: |
0756ea3e | 813 | return bpf_get_trace_printk_proto(); |
ab1973d3 AS |
814 | case BPF_FUNC_get_smp_processor_id: |
815 | return &bpf_get_smp_processor_id_proto; | |
2d0e30c3 DB |
816 | case BPF_FUNC_get_numa_node_id: |
817 | return &bpf_get_numa_node_id_proto; | |
35578d79 KX |
818 | case BPF_FUNC_perf_event_read: |
819 | return &bpf_perf_event_read_proto; | |
96ae5227 SD |
820 | case BPF_FUNC_probe_write_user: |
821 | return bpf_get_probe_write_proto(); | |
60d20f91 SD |
822 | case BPF_FUNC_current_task_under_cgroup: |
823 | return &bpf_current_task_under_cgroup_proto; | |
8937bd80 AS |
824 | case BPF_FUNC_get_prandom_u32: |
825 | return &bpf_get_prandom_u32_proto; | |
6ae08ae3 DB |
826 | case BPF_FUNC_probe_read_user: |
827 | return &bpf_probe_read_user_proto; | |
828 | case BPF_FUNC_probe_read_kernel: | |
829 | return &bpf_probe_read_kernel_proto; | |
830 | case BPF_FUNC_probe_read: | |
831 | return &bpf_probe_read_compat_proto; | |
832 | case BPF_FUNC_probe_read_user_str: | |
833 | return &bpf_probe_read_user_str_proto; | |
834 | case BPF_FUNC_probe_read_kernel_str: | |
835 | return &bpf_probe_read_kernel_str_proto; | |
a5e8c070 | 836 | case BPF_FUNC_probe_read_str: |
6ae08ae3 | 837 | return &bpf_probe_read_compat_str_proto; |
34ea38ca | 838 | #ifdef CONFIG_CGROUPS |
bf6fa2c8 YS |
839 | case BPF_FUNC_get_current_cgroup_id: |
840 | return &bpf_get_current_cgroup_id_proto; | |
34ea38ca | 841 | #endif |
8b401f9e YS |
842 | case BPF_FUNC_send_signal: |
843 | return &bpf_send_signal_proto; | |
8482941f YS |
844 | case BPF_FUNC_send_signal_thread: |
845 | return &bpf_send_signal_thread_proto; | |
b80b033b SL |
846 | case BPF_FUNC_perf_event_read_value: |
847 | return &bpf_perf_event_read_value_proto; | |
9fd82b61 AS |
848 | default: |
849 | return NULL; | |
850 | } | |
851 | } | |
852 | ||
5e43f899 AI |
853 | static const struct bpf_func_proto * |
854 | kprobe_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) | |
9fd82b61 AS |
855 | { |
856 | switch (func_id) { | |
a43eec30 AS |
857 | case BPF_FUNC_perf_event_output: |
858 | return &bpf_perf_event_output_proto; | |
d5a3b1f6 AS |
859 | case BPF_FUNC_get_stackid: |
860 | return &bpf_get_stackid_proto; | |
c195651e YS |
861 | case BPF_FUNC_get_stack: |
862 | return &bpf_get_stack_proto; | |
9802d865 JB |
863 | #ifdef CONFIG_BPF_KPROBE_OVERRIDE |
864 | case BPF_FUNC_override_return: | |
865 | return &bpf_override_return_proto; | |
866 | #endif | |
2541517c | 867 | default: |
5e43f899 | 868 | return tracing_func_proto(func_id, prog); |
2541517c AS |
869 | } |
870 | } | |
871 | ||
872 | /* bpf+kprobe programs can access fields of 'struct pt_regs' */ | |
19de99f7 | 873 | static bool kprobe_prog_is_valid_access(int off, int size, enum bpf_access_type type, |
5e43f899 | 874 | const struct bpf_prog *prog, |
23994631 | 875 | struct bpf_insn_access_aux *info) |
2541517c | 876 | { |
2541517c AS |
877 | if (off < 0 || off >= sizeof(struct pt_regs)) |
878 | return false; | |
2541517c AS |
879 | if (type != BPF_READ) |
880 | return false; | |
2541517c AS |
881 | if (off % size != 0) |
882 | return false; | |
2d071c64 DB |
883 | /* |
884 | * Assertion for 32 bit to make sure last 8 byte access | |
885 | * (BPF_DW) to the last 4 byte member is disallowed. | |
886 | */ | |
887 | if (off + size > sizeof(struct pt_regs)) | |
888 | return false; | |
889 | ||
2541517c AS |
890 | return true; |
891 | } | |
892 | ||
7de16e3a | 893 | const struct bpf_verifier_ops kprobe_verifier_ops = { |
2541517c AS |
894 | .get_func_proto = kprobe_prog_func_proto, |
895 | .is_valid_access = kprobe_prog_is_valid_access, | |
896 | }; | |
897 | ||
7de16e3a JK |
898 | const struct bpf_prog_ops kprobe_prog_ops = { |
899 | }; | |
900 | ||
f3694e00 DB |
901 | BPF_CALL_5(bpf_perf_event_output_tp, void *, tp_buff, struct bpf_map *, map, |
902 | u64, flags, void *, data, u64, size) | |
9940d67c | 903 | { |
f3694e00 DB |
904 | struct pt_regs *regs = *(struct pt_regs **)tp_buff; |
905 | ||
9940d67c AS |
906 | /* |
907 | * r1 points to perf tracepoint buffer where first 8 bytes are hidden | |
908 | * from bpf program and contain a pointer to 'struct pt_regs'. Fetch it | |
f3694e00 | 909 | * from there and call the same bpf_perf_event_output() helper inline. |
9940d67c | 910 | */ |
f3694e00 | 911 | return ____bpf_perf_event_output(regs, map, flags, data, size); |
9940d67c AS |
912 | } |
913 | ||
914 | static const struct bpf_func_proto bpf_perf_event_output_proto_tp = { | |
915 | .func = bpf_perf_event_output_tp, | |
916 | .gpl_only = true, | |
917 | .ret_type = RET_INTEGER, | |
918 | .arg1_type = ARG_PTR_TO_CTX, | |
919 | .arg2_type = ARG_CONST_MAP_PTR, | |
920 | .arg3_type = ARG_ANYTHING, | |
39f19ebb | 921 | .arg4_type = ARG_PTR_TO_MEM, |
a60dd35d | 922 | .arg5_type = ARG_CONST_SIZE_OR_ZERO, |
9940d67c AS |
923 | }; |
924 | ||
f3694e00 DB |
925 | BPF_CALL_3(bpf_get_stackid_tp, void *, tp_buff, struct bpf_map *, map, |
926 | u64, flags) | |
9940d67c | 927 | { |
f3694e00 | 928 | struct pt_regs *regs = *(struct pt_regs **)tp_buff; |
9940d67c | 929 | |
f3694e00 DB |
930 | /* |
931 | * Same comment as in bpf_perf_event_output_tp(), only that this time | |
932 | * the other helper's function body cannot be inlined due to being | |
933 | * external, thus we need to call raw helper function. | |
934 | */ | |
935 | return bpf_get_stackid((unsigned long) regs, (unsigned long) map, | |
936 | flags, 0, 0); | |
9940d67c AS |
937 | } |
938 | ||
939 | static const struct bpf_func_proto bpf_get_stackid_proto_tp = { | |
940 | .func = bpf_get_stackid_tp, | |
941 | .gpl_only = true, | |
942 | .ret_type = RET_INTEGER, | |
943 | .arg1_type = ARG_PTR_TO_CTX, | |
944 | .arg2_type = ARG_CONST_MAP_PTR, | |
945 | .arg3_type = ARG_ANYTHING, | |
946 | }; | |
947 | ||
c195651e YS |
948 | BPF_CALL_4(bpf_get_stack_tp, void *, tp_buff, void *, buf, u32, size, |
949 | u64, flags) | |
950 | { | |
951 | struct pt_regs *regs = *(struct pt_regs **)tp_buff; | |
952 | ||
953 | return bpf_get_stack((unsigned long) regs, (unsigned long) buf, | |
954 | (unsigned long) size, flags, 0); | |
955 | } | |
956 | ||
957 | static const struct bpf_func_proto bpf_get_stack_proto_tp = { | |
958 | .func = bpf_get_stack_tp, | |
959 | .gpl_only = true, | |
960 | .ret_type = RET_INTEGER, | |
961 | .arg1_type = ARG_PTR_TO_CTX, | |
962 | .arg2_type = ARG_PTR_TO_UNINIT_MEM, | |
963 | .arg3_type = ARG_CONST_SIZE_OR_ZERO, | |
964 | .arg4_type = ARG_ANYTHING, | |
965 | }; | |
966 | ||
5e43f899 AI |
967 | static const struct bpf_func_proto * |
968 | tp_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) | |
f005afed YS |
969 | { |
970 | switch (func_id) { | |
971 | case BPF_FUNC_perf_event_output: | |
972 | return &bpf_perf_event_output_proto_tp; | |
973 | case BPF_FUNC_get_stackid: | |
974 | return &bpf_get_stackid_proto_tp; | |
c195651e YS |
975 | case BPF_FUNC_get_stack: |
976 | return &bpf_get_stack_proto_tp; | |
f005afed | 977 | default: |
5e43f899 | 978 | return tracing_func_proto(func_id, prog); |
f005afed YS |
979 | } |
980 | } | |
981 | ||
982 | static bool tp_prog_is_valid_access(int off, int size, enum bpf_access_type type, | |
5e43f899 | 983 | const struct bpf_prog *prog, |
f005afed YS |
984 | struct bpf_insn_access_aux *info) |
985 | { | |
986 | if (off < sizeof(void *) || off >= PERF_MAX_TRACE_SIZE) | |
987 | return false; | |
988 | if (type != BPF_READ) | |
989 | return false; | |
990 | if (off % size != 0) | |
991 | return false; | |
992 | ||
993 | BUILD_BUG_ON(PERF_MAX_TRACE_SIZE % sizeof(__u64)); | |
994 | return true; | |
995 | } | |
996 | ||
997 | const struct bpf_verifier_ops tracepoint_verifier_ops = { | |
998 | .get_func_proto = tp_prog_func_proto, | |
999 | .is_valid_access = tp_prog_is_valid_access, | |
1000 | }; | |
1001 | ||
1002 | const struct bpf_prog_ops tracepoint_prog_ops = { | |
1003 | }; | |
1004 | ||
1005 | BPF_CALL_3(bpf_perf_prog_read_value, struct bpf_perf_event_data_kern *, ctx, | |
4bebdc7a YS |
1006 | struct bpf_perf_event_value *, buf, u32, size) |
1007 | { | |
1008 | int err = -EINVAL; | |
1009 | ||
1010 | if (unlikely(size != sizeof(struct bpf_perf_event_value))) | |
1011 | goto clear; | |
1012 | err = perf_event_read_local(ctx->event, &buf->counter, &buf->enabled, | |
1013 | &buf->running); | |
1014 | if (unlikely(err)) | |
1015 | goto clear; | |
1016 | return 0; | |
1017 | clear: | |
1018 | memset(buf, 0, size); | |
1019 | return err; | |
1020 | } | |
1021 | ||
f005afed YS |
1022 | static const struct bpf_func_proto bpf_perf_prog_read_value_proto = { |
1023 | .func = bpf_perf_prog_read_value, | |
4bebdc7a YS |
1024 | .gpl_only = true, |
1025 | .ret_type = RET_INTEGER, | |
1026 | .arg1_type = ARG_PTR_TO_CTX, | |
1027 | .arg2_type = ARG_PTR_TO_UNINIT_MEM, | |
1028 | .arg3_type = ARG_CONST_SIZE, | |
1029 | }; | |
1030 | ||
5e43f899 AI |
1031 | static const struct bpf_func_proto * |
1032 | pe_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) | |
9fd82b61 AS |
1033 | { |
1034 | switch (func_id) { | |
1035 | case BPF_FUNC_perf_event_output: | |
9940d67c | 1036 | return &bpf_perf_event_output_proto_tp; |
9fd82b61 | 1037 | case BPF_FUNC_get_stackid: |
9940d67c | 1038 | return &bpf_get_stackid_proto_tp; |
c195651e YS |
1039 | case BPF_FUNC_get_stack: |
1040 | return &bpf_get_stack_proto_tp; | |
4bebdc7a | 1041 | case BPF_FUNC_perf_prog_read_value: |
f005afed | 1042 | return &bpf_perf_prog_read_value_proto; |
9fd82b61 | 1043 | default: |
5e43f899 | 1044 | return tracing_func_proto(func_id, prog); |
9fd82b61 AS |
1045 | } |
1046 | } | |
1047 | ||
c4f6699d AS |
1048 | /* |
1049 | * bpf_raw_tp_regs are separate from bpf_pt_regs used from skb/xdp | |
1050 | * to avoid potential recursive reuse issue when/if tracepoints are added | |
9594dc3c MM |
1051 | * inside bpf_*_event_output, bpf_get_stackid and/or bpf_get_stack. |
1052 | * | |
1053 | * Since raw tracepoints run despite bpf_prog_active, support concurrent usage | |
1054 | * in normal, irq, and nmi context. | |
c4f6699d | 1055 | */ |
9594dc3c MM |
1056 | struct bpf_raw_tp_regs { |
1057 | struct pt_regs regs[3]; | |
1058 | }; | |
1059 | static DEFINE_PER_CPU(struct bpf_raw_tp_regs, bpf_raw_tp_regs); | |
1060 | static DEFINE_PER_CPU(int, bpf_raw_tp_nest_level); | |
1061 | static struct pt_regs *get_bpf_raw_tp_regs(void) | |
1062 | { | |
1063 | struct bpf_raw_tp_regs *tp_regs = this_cpu_ptr(&bpf_raw_tp_regs); | |
1064 | int nest_level = this_cpu_inc_return(bpf_raw_tp_nest_level); | |
1065 | ||
1066 | if (WARN_ON_ONCE(nest_level > ARRAY_SIZE(tp_regs->regs))) { | |
1067 | this_cpu_dec(bpf_raw_tp_nest_level); | |
1068 | return ERR_PTR(-EBUSY); | |
1069 | } | |
1070 | ||
1071 | return &tp_regs->regs[nest_level - 1]; | |
1072 | } | |
1073 | ||
1074 | static void put_bpf_raw_tp_regs(void) | |
1075 | { | |
1076 | this_cpu_dec(bpf_raw_tp_nest_level); | |
1077 | } | |
1078 | ||
c4f6699d AS |
1079 | BPF_CALL_5(bpf_perf_event_output_raw_tp, struct bpf_raw_tracepoint_args *, args, |
1080 | struct bpf_map *, map, u64, flags, void *, data, u64, size) | |
1081 | { | |
9594dc3c MM |
1082 | struct pt_regs *regs = get_bpf_raw_tp_regs(); |
1083 | int ret; | |
1084 | ||
1085 | if (IS_ERR(regs)) | |
1086 | return PTR_ERR(regs); | |
c4f6699d AS |
1087 | |
1088 | perf_fetch_caller_regs(regs); | |
9594dc3c MM |
1089 | ret = ____bpf_perf_event_output(regs, map, flags, data, size); |
1090 | ||
1091 | put_bpf_raw_tp_regs(); | |
1092 | return ret; | |
c4f6699d AS |
1093 | } |
1094 | ||
1095 | static const struct bpf_func_proto bpf_perf_event_output_proto_raw_tp = { | |
1096 | .func = bpf_perf_event_output_raw_tp, | |
1097 | .gpl_only = true, | |
1098 | .ret_type = RET_INTEGER, | |
1099 | .arg1_type = ARG_PTR_TO_CTX, | |
1100 | .arg2_type = ARG_CONST_MAP_PTR, | |
1101 | .arg3_type = ARG_ANYTHING, | |
1102 | .arg4_type = ARG_PTR_TO_MEM, | |
1103 | .arg5_type = ARG_CONST_SIZE_OR_ZERO, | |
1104 | }; | |
1105 | ||
a7658e1a AS |
1106 | extern const struct bpf_func_proto bpf_skb_output_proto; |
1107 | ||
c4f6699d AS |
1108 | BPF_CALL_3(bpf_get_stackid_raw_tp, struct bpf_raw_tracepoint_args *, args, |
1109 | struct bpf_map *, map, u64, flags) | |
1110 | { | |
9594dc3c MM |
1111 | struct pt_regs *regs = get_bpf_raw_tp_regs(); |
1112 | int ret; | |
1113 | ||
1114 | if (IS_ERR(regs)) | |
1115 | return PTR_ERR(regs); | |
c4f6699d AS |
1116 | |
1117 | perf_fetch_caller_regs(regs); | |
1118 | /* similar to bpf_perf_event_output_tp, but pt_regs fetched differently */ | |
9594dc3c MM |
1119 | ret = bpf_get_stackid((unsigned long) regs, (unsigned long) map, |
1120 | flags, 0, 0); | |
1121 | put_bpf_raw_tp_regs(); | |
1122 | return ret; | |
c4f6699d AS |
1123 | } |
1124 | ||
1125 | static const struct bpf_func_proto bpf_get_stackid_proto_raw_tp = { | |
1126 | .func = bpf_get_stackid_raw_tp, | |
1127 | .gpl_only = true, | |
1128 | .ret_type = RET_INTEGER, | |
1129 | .arg1_type = ARG_PTR_TO_CTX, | |
1130 | .arg2_type = ARG_CONST_MAP_PTR, | |
1131 | .arg3_type = ARG_ANYTHING, | |
1132 | }; | |
1133 | ||
c195651e YS |
1134 | BPF_CALL_4(bpf_get_stack_raw_tp, struct bpf_raw_tracepoint_args *, args, |
1135 | void *, buf, u32, size, u64, flags) | |
1136 | { | |
9594dc3c MM |
1137 | struct pt_regs *regs = get_bpf_raw_tp_regs(); |
1138 | int ret; | |
1139 | ||
1140 | if (IS_ERR(regs)) | |
1141 | return PTR_ERR(regs); | |
c195651e YS |
1142 | |
1143 | perf_fetch_caller_regs(regs); | |
9594dc3c MM |
1144 | ret = bpf_get_stack((unsigned long) regs, (unsigned long) buf, |
1145 | (unsigned long) size, flags, 0); | |
1146 | put_bpf_raw_tp_regs(); | |
1147 | return ret; | |
c195651e YS |
1148 | } |
1149 | ||
1150 | static const struct bpf_func_proto bpf_get_stack_proto_raw_tp = { | |
1151 | .func = bpf_get_stack_raw_tp, | |
1152 | .gpl_only = true, | |
1153 | .ret_type = RET_INTEGER, | |
1154 | .arg1_type = ARG_PTR_TO_CTX, | |
1155 | .arg2_type = ARG_PTR_TO_MEM, | |
1156 | .arg3_type = ARG_CONST_SIZE_OR_ZERO, | |
1157 | .arg4_type = ARG_ANYTHING, | |
1158 | }; | |
1159 | ||
5e43f899 AI |
1160 | static const struct bpf_func_proto * |
1161 | raw_tp_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) | |
c4f6699d AS |
1162 | { |
1163 | switch (func_id) { | |
1164 | case BPF_FUNC_perf_event_output: | |
1165 | return &bpf_perf_event_output_proto_raw_tp; | |
1166 | case BPF_FUNC_get_stackid: | |
1167 | return &bpf_get_stackid_proto_raw_tp; | |
c195651e YS |
1168 | case BPF_FUNC_get_stack: |
1169 | return &bpf_get_stack_proto_raw_tp; | |
c4f6699d | 1170 | default: |
5e43f899 | 1171 | return tracing_func_proto(func_id, prog); |
c4f6699d AS |
1172 | } |
1173 | } | |
1174 | ||
f1b9509c AS |
1175 | static const struct bpf_func_proto * |
1176 | tracing_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) | |
1177 | { | |
1178 | switch (func_id) { | |
1179 | #ifdef CONFIG_NET | |
1180 | case BPF_FUNC_skb_output: | |
1181 | return &bpf_skb_output_proto; | |
1182 | #endif | |
1183 | default: | |
1184 | return raw_tp_prog_func_proto(func_id, prog); | |
1185 | } | |
1186 | } | |
1187 | ||
c4f6699d AS |
1188 | static bool raw_tp_prog_is_valid_access(int off, int size, |
1189 | enum bpf_access_type type, | |
5e43f899 | 1190 | const struct bpf_prog *prog, |
c4f6699d AS |
1191 | struct bpf_insn_access_aux *info) |
1192 | { | |
f1b9509c AS |
1193 | if (off < 0 || off >= sizeof(__u64) * MAX_BPF_FUNC_ARGS) |
1194 | return false; | |
1195 | if (type != BPF_READ) | |
1196 | return false; | |
1197 | if (off % size != 0) | |
1198 | return false; | |
1199 | return true; | |
1200 | } | |
1201 | ||
1202 | static bool tracing_prog_is_valid_access(int off, int size, | |
1203 | enum bpf_access_type type, | |
1204 | const struct bpf_prog *prog, | |
1205 | struct bpf_insn_access_aux *info) | |
1206 | { | |
1207 | if (off < 0 || off >= sizeof(__u64) * MAX_BPF_FUNC_ARGS) | |
c4f6699d AS |
1208 | return false; |
1209 | if (type != BPF_READ) | |
1210 | return false; | |
1211 | if (off % size != 0) | |
1212 | return false; | |
9e15db66 | 1213 | return btf_ctx_access(off, size, type, prog, info); |
c4f6699d AS |
1214 | } |
1215 | ||
1216 | const struct bpf_verifier_ops raw_tracepoint_verifier_ops = { | |
1217 | .get_func_proto = raw_tp_prog_func_proto, | |
1218 | .is_valid_access = raw_tp_prog_is_valid_access, | |
1219 | }; | |
1220 | ||
1221 | const struct bpf_prog_ops raw_tracepoint_prog_ops = { | |
1222 | }; | |
1223 | ||
f1b9509c AS |
1224 | const struct bpf_verifier_ops tracing_verifier_ops = { |
1225 | .get_func_proto = tracing_prog_func_proto, | |
1226 | .is_valid_access = tracing_prog_is_valid_access, | |
1227 | }; | |
1228 | ||
1229 | const struct bpf_prog_ops tracing_prog_ops = { | |
1230 | }; | |
1231 | ||
9df1c28b MM |
1232 | static bool raw_tp_writable_prog_is_valid_access(int off, int size, |
1233 | enum bpf_access_type type, | |
1234 | const struct bpf_prog *prog, | |
1235 | struct bpf_insn_access_aux *info) | |
1236 | { | |
1237 | if (off == 0) { | |
1238 | if (size != sizeof(u64) || type != BPF_READ) | |
1239 | return false; | |
1240 | info->reg_type = PTR_TO_TP_BUFFER; | |
1241 | } | |
1242 | return raw_tp_prog_is_valid_access(off, size, type, prog, info); | |
1243 | } | |
1244 | ||
1245 | const struct bpf_verifier_ops raw_tracepoint_writable_verifier_ops = { | |
1246 | .get_func_proto = raw_tp_prog_func_proto, | |
1247 | .is_valid_access = raw_tp_writable_prog_is_valid_access, | |
1248 | }; | |
1249 | ||
1250 | const struct bpf_prog_ops raw_tracepoint_writable_prog_ops = { | |
1251 | }; | |
1252 | ||
0515e599 | 1253 | static bool pe_prog_is_valid_access(int off, int size, enum bpf_access_type type, |
5e43f899 | 1254 | const struct bpf_prog *prog, |
23994631 | 1255 | struct bpf_insn_access_aux *info) |
0515e599 | 1256 | { |
95da0cdb | 1257 | const int size_u64 = sizeof(u64); |
31fd8581 | 1258 | |
0515e599 AS |
1259 | if (off < 0 || off >= sizeof(struct bpf_perf_event_data)) |
1260 | return false; | |
1261 | if (type != BPF_READ) | |
1262 | return false; | |
bc23105c DB |
1263 | if (off % size != 0) { |
1264 | if (sizeof(unsigned long) != 4) | |
1265 | return false; | |
1266 | if (size != 8) | |
1267 | return false; | |
1268 | if (off % size != 4) | |
1269 | return false; | |
1270 | } | |
31fd8581 | 1271 | |
f96da094 DB |
1272 | switch (off) { |
1273 | case bpf_ctx_range(struct bpf_perf_event_data, sample_period): | |
95da0cdb TQ |
1274 | bpf_ctx_record_field_size(info, size_u64); |
1275 | if (!bpf_ctx_narrow_access_ok(off, size, size_u64)) | |
1276 | return false; | |
1277 | break; | |
1278 | case bpf_ctx_range(struct bpf_perf_event_data, addr): | |
1279 | bpf_ctx_record_field_size(info, size_u64); | |
1280 | if (!bpf_ctx_narrow_access_ok(off, size, size_u64)) | |
23994631 | 1281 | return false; |
f96da094 DB |
1282 | break; |
1283 | default: | |
0515e599 AS |
1284 | if (size != sizeof(long)) |
1285 | return false; | |
1286 | } | |
f96da094 | 1287 | |
0515e599 AS |
1288 | return true; |
1289 | } | |
1290 | ||
6b8cc1d1 DB |
1291 | static u32 pe_prog_convert_ctx_access(enum bpf_access_type type, |
1292 | const struct bpf_insn *si, | |
0515e599 | 1293 | struct bpf_insn *insn_buf, |
f96da094 | 1294 | struct bpf_prog *prog, u32 *target_size) |
0515e599 AS |
1295 | { |
1296 | struct bpf_insn *insn = insn_buf; | |
1297 | ||
6b8cc1d1 | 1298 | switch (si->off) { |
0515e599 | 1299 | case offsetof(struct bpf_perf_event_data, sample_period): |
f035a515 | 1300 | *insn++ = BPF_LDX_MEM(BPF_FIELD_SIZEOF(struct bpf_perf_event_data_kern, |
6b8cc1d1 | 1301 | data), si->dst_reg, si->src_reg, |
0515e599 | 1302 | offsetof(struct bpf_perf_event_data_kern, data)); |
6b8cc1d1 | 1303 | *insn++ = BPF_LDX_MEM(BPF_DW, si->dst_reg, si->dst_reg, |
f96da094 DB |
1304 | bpf_target_off(struct perf_sample_data, period, 8, |
1305 | target_size)); | |
0515e599 | 1306 | break; |
95da0cdb TQ |
1307 | case offsetof(struct bpf_perf_event_data, addr): |
1308 | *insn++ = BPF_LDX_MEM(BPF_FIELD_SIZEOF(struct bpf_perf_event_data_kern, | |
1309 | data), si->dst_reg, si->src_reg, | |
1310 | offsetof(struct bpf_perf_event_data_kern, data)); | |
1311 | *insn++ = BPF_LDX_MEM(BPF_DW, si->dst_reg, si->dst_reg, | |
1312 | bpf_target_off(struct perf_sample_data, addr, 8, | |
1313 | target_size)); | |
1314 | break; | |
0515e599 | 1315 | default: |
f035a515 | 1316 | *insn++ = BPF_LDX_MEM(BPF_FIELD_SIZEOF(struct bpf_perf_event_data_kern, |
6b8cc1d1 | 1317 | regs), si->dst_reg, si->src_reg, |
0515e599 | 1318 | offsetof(struct bpf_perf_event_data_kern, regs)); |
6b8cc1d1 DB |
1319 | *insn++ = BPF_LDX_MEM(BPF_SIZEOF(long), si->dst_reg, si->dst_reg, |
1320 | si->off); | |
0515e599 AS |
1321 | break; |
1322 | } | |
1323 | ||
1324 | return insn - insn_buf; | |
1325 | } | |
1326 | ||
7de16e3a | 1327 | const struct bpf_verifier_ops perf_event_verifier_ops = { |
f005afed | 1328 | .get_func_proto = pe_prog_func_proto, |
0515e599 AS |
1329 | .is_valid_access = pe_prog_is_valid_access, |
1330 | .convert_ctx_access = pe_prog_convert_ctx_access, | |
1331 | }; | |
7de16e3a JK |
1332 | |
1333 | const struct bpf_prog_ops perf_event_prog_ops = { | |
1334 | }; | |
e87c6bc3 YS |
1335 | |
1336 | static DEFINE_MUTEX(bpf_event_mutex); | |
1337 | ||
c8c088ba YS |
1338 | #define BPF_TRACE_MAX_PROGS 64 |
1339 | ||
e87c6bc3 YS |
1340 | int perf_event_attach_bpf_prog(struct perf_event *event, |
1341 | struct bpf_prog *prog) | |
1342 | { | |
e672db03 | 1343 | struct bpf_prog_array *old_array; |
e87c6bc3 YS |
1344 | struct bpf_prog_array *new_array; |
1345 | int ret = -EEXIST; | |
1346 | ||
9802d865 | 1347 | /* |
b4da3340 MH |
1348 | * Kprobe override only works if they are on the function entry, |
1349 | * and only if they are on the opt-in list. | |
9802d865 JB |
1350 | */ |
1351 | if (prog->kprobe_override && | |
b4da3340 | 1352 | (!trace_kprobe_on_func_entry(event->tp_event) || |
9802d865 JB |
1353 | !trace_kprobe_error_injectable(event->tp_event))) |
1354 | return -EINVAL; | |
1355 | ||
e87c6bc3 YS |
1356 | mutex_lock(&bpf_event_mutex); |
1357 | ||
1358 | if (event->prog) | |
07c41a29 | 1359 | goto unlock; |
e87c6bc3 | 1360 | |
e672db03 | 1361 | old_array = bpf_event_rcu_dereference(event->tp_event->prog_array); |
c8c088ba YS |
1362 | if (old_array && |
1363 | bpf_prog_array_length(old_array) >= BPF_TRACE_MAX_PROGS) { | |
1364 | ret = -E2BIG; | |
1365 | goto unlock; | |
1366 | } | |
1367 | ||
e87c6bc3 YS |
1368 | ret = bpf_prog_array_copy(old_array, NULL, prog, &new_array); |
1369 | if (ret < 0) | |
07c41a29 | 1370 | goto unlock; |
e87c6bc3 YS |
1371 | |
1372 | /* set the new array to event->tp_event and set event->prog */ | |
1373 | event->prog = prog; | |
1374 | rcu_assign_pointer(event->tp_event->prog_array, new_array); | |
1375 | bpf_prog_array_free(old_array); | |
1376 | ||
07c41a29 | 1377 | unlock: |
e87c6bc3 YS |
1378 | mutex_unlock(&bpf_event_mutex); |
1379 | return ret; | |
1380 | } | |
1381 | ||
1382 | void perf_event_detach_bpf_prog(struct perf_event *event) | |
1383 | { | |
e672db03 | 1384 | struct bpf_prog_array *old_array; |
e87c6bc3 YS |
1385 | struct bpf_prog_array *new_array; |
1386 | int ret; | |
1387 | ||
1388 | mutex_lock(&bpf_event_mutex); | |
1389 | ||
1390 | if (!event->prog) | |
07c41a29 | 1391 | goto unlock; |
e87c6bc3 | 1392 | |
e672db03 | 1393 | old_array = bpf_event_rcu_dereference(event->tp_event->prog_array); |
e87c6bc3 | 1394 | ret = bpf_prog_array_copy(old_array, event->prog, NULL, &new_array); |
170a7e3e SY |
1395 | if (ret == -ENOENT) |
1396 | goto unlock; | |
e87c6bc3 YS |
1397 | if (ret < 0) { |
1398 | bpf_prog_array_delete_safe(old_array, event->prog); | |
1399 | } else { | |
1400 | rcu_assign_pointer(event->tp_event->prog_array, new_array); | |
1401 | bpf_prog_array_free(old_array); | |
1402 | } | |
1403 | ||
1404 | bpf_prog_put(event->prog); | |
1405 | event->prog = NULL; | |
1406 | ||
07c41a29 | 1407 | unlock: |
e87c6bc3 YS |
1408 | mutex_unlock(&bpf_event_mutex); |
1409 | } | |
f371b304 | 1410 | |
f4e2298e | 1411 | int perf_event_query_prog_array(struct perf_event *event, void __user *info) |
f371b304 YS |
1412 | { |
1413 | struct perf_event_query_bpf __user *uquery = info; | |
1414 | struct perf_event_query_bpf query = {}; | |
e672db03 | 1415 | struct bpf_prog_array *progs; |
3a38bb98 | 1416 | u32 *ids, prog_cnt, ids_len; |
f371b304 YS |
1417 | int ret; |
1418 | ||
1419 | if (!capable(CAP_SYS_ADMIN)) | |
1420 | return -EPERM; | |
1421 | if (event->attr.type != PERF_TYPE_TRACEPOINT) | |
1422 | return -EINVAL; | |
1423 | if (copy_from_user(&query, uquery, sizeof(query))) | |
1424 | return -EFAULT; | |
3a38bb98 YS |
1425 | |
1426 | ids_len = query.ids_len; | |
1427 | if (ids_len > BPF_TRACE_MAX_PROGS) | |
9c481b90 | 1428 | return -E2BIG; |
3a38bb98 YS |
1429 | ids = kcalloc(ids_len, sizeof(u32), GFP_USER | __GFP_NOWARN); |
1430 | if (!ids) | |
1431 | return -ENOMEM; | |
1432 | /* | |
1433 | * The above kcalloc returns ZERO_SIZE_PTR when ids_len = 0, which | |
1434 | * is required when user only wants to check for uquery->prog_cnt. | |
1435 | * There is no need to check for it since the case is handled | |
1436 | * gracefully in bpf_prog_array_copy_info. | |
1437 | */ | |
f371b304 YS |
1438 | |
1439 | mutex_lock(&bpf_event_mutex); | |
e672db03 SF |
1440 | progs = bpf_event_rcu_dereference(event->tp_event->prog_array); |
1441 | ret = bpf_prog_array_copy_info(progs, ids, ids_len, &prog_cnt); | |
f371b304 YS |
1442 | mutex_unlock(&bpf_event_mutex); |
1443 | ||
3a38bb98 YS |
1444 | if (copy_to_user(&uquery->prog_cnt, &prog_cnt, sizeof(prog_cnt)) || |
1445 | copy_to_user(uquery->ids, ids, ids_len * sizeof(u32))) | |
1446 | ret = -EFAULT; | |
1447 | ||
1448 | kfree(ids); | |
f371b304 YS |
1449 | return ret; |
1450 | } | |
c4f6699d AS |
1451 | |
1452 | extern struct bpf_raw_event_map __start__bpf_raw_tp[]; | |
1453 | extern struct bpf_raw_event_map __stop__bpf_raw_tp[]; | |
1454 | ||
a38d1107 | 1455 | struct bpf_raw_event_map *bpf_get_raw_tracepoint(const char *name) |
c4f6699d AS |
1456 | { |
1457 | struct bpf_raw_event_map *btp = __start__bpf_raw_tp; | |
1458 | ||
1459 | for (; btp < __stop__bpf_raw_tp; btp++) { | |
1460 | if (!strcmp(btp->tp->name, name)) | |
1461 | return btp; | |
1462 | } | |
a38d1107 MM |
1463 | |
1464 | return bpf_get_raw_tracepoint_module(name); | |
1465 | } | |
1466 | ||
1467 | void bpf_put_raw_tracepoint(struct bpf_raw_event_map *btp) | |
1468 | { | |
1469 | struct module *mod = __module_address((unsigned long)btp); | |
1470 | ||
1471 | if (mod) | |
1472 | module_put(mod); | |
c4f6699d AS |
1473 | } |
1474 | ||
1475 | static __always_inline | |
1476 | void __bpf_trace_run(struct bpf_prog *prog, u64 *args) | |
1477 | { | |
1478 | rcu_read_lock(); | |
1479 | preempt_disable(); | |
1480 | (void) BPF_PROG_RUN(prog, args); | |
1481 | preempt_enable(); | |
1482 | rcu_read_unlock(); | |
1483 | } | |
1484 | ||
1485 | #define UNPACK(...) __VA_ARGS__ | |
1486 | #define REPEAT_1(FN, DL, X, ...) FN(X) | |
1487 | #define REPEAT_2(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_1(FN, DL, __VA_ARGS__) | |
1488 | #define REPEAT_3(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_2(FN, DL, __VA_ARGS__) | |
1489 | #define REPEAT_4(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_3(FN, DL, __VA_ARGS__) | |
1490 | #define REPEAT_5(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_4(FN, DL, __VA_ARGS__) | |
1491 | #define REPEAT_6(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_5(FN, DL, __VA_ARGS__) | |
1492 | #define REPEAT_7(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_6(FN, DL, __VA_ARGS__) | |
1493 | #define REPEAT_8(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_7(FN, DL, __VA_ARGS__) | |
1494 | #define REPEAT_9(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_8(FN, DL, __VA_ARGS__) | |
1495 | #define REPEAT_10(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_9(FN, DL, __VA_ARGS__) | |
1496 | #define REPEAT_11(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_10(FN, DL, __VA_ARGS__) | |
1497 | #define REPEAT_12(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_11(FN, DL, __VA_ARGS__) | |
1498 | #define REPEAT(X, FN, DL, ...) REPEAT_##X(FN, DL, __VA_ARGS__) | |
1499 | ||
1500 | #define SARG(X) u64 arg##X | |
1501 | #define COPY(X) args[X] = arg##X | |
1502 | ||
1503 | #define __DL_COM (,) | |
1504 | #define __DL_SEM (;) | |
1505 | ||
1506 | #define __SEQ_0_11 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11 | |
1507 | ||
1508 | #define BPF_TRACE_DEFN_x(x) \ | |
1509 | void bpf_trace_run##x(struct bpf_prog *prog, \ | |
1510 | REPEAT(x, SARG, __DL_COM, __SEQ_0_11)) \ | |
1511 | { \ | |
1512 | u64 args[x]; \ | |
1513 | REPEAT(x, COPY, __DL_SEM, __SEQ_0_11); \ | |
1514 | __bpf_trace_run(prog, args); \ | |
1515 | } \ | |
1516 | EXPORT_SYMBOL_GPL(bpf_trace_run##x) | |
1517 | BPF_TRACE_DEFN_x(1); | |
1518 | BPF_TRACE_DEFN_x(2); | |
1519 | BPF_TRACE_DEFN_x(3); | |
1520 | BPF_TRACE_DEFN_x(4); | |
1521 | BPF_TRACE_DEFN_x(5); | |
1522 | BPF_TRACE_DEFN_x(6); | |
1523 | BPF_TRACE_DEFN_x(7); | |
1524 | BPF_TRACE_DEFN_x(8); | |
1525 | BPF_TRACE_DEFN_x(9); | |
1526 | BPF_TRACE_DEFN_x(10); | |
1527 | BPF_TRACE_DEFN_x(11); | |
1528 | BPF_TRACE_DEFN_x(12); | |
1529 | ||
1530 | static int __bpf_probe_register(struct bpf_raw_event_map *btp, struct bpf_prog *prog) | |
1531 | { | |
1532 | struct tracepoint *tp = btp->tp; | |
1533 | ||
1534 | /* | |
1535 | * check that program doesn't access arguments beyond what's | |
1536 | * available in this tracepoint | |
1537 | */ | |
1538 | if (prog->aux->max_ctx_offset > btp->num_args * sizeof(u64)) | |
1539 | return -EINVAL; | |
1540 | ||
9df1c28b MM |
1541 | if (prog->aux->max_tp_access > btp->writable_size) |
1542 | return -EINVAL; | |
1543 | ||
c4f6699d AS |
1544 | return tracepoint_probe_register(tp, (void *)btp->bpf_func, prog); |
1545 | } | |
1546 | ||
1547 | int bpf_probe_register(struct bpf_raw_event_map *btp, struct bpf_prog *prog) | |
1548 | { | |
e16ec340 | 1549 | return __bpf_probe_register(btp, prog); |
c4f6699d AS |
1550 | } |
1551 | ||
1552 | int bpf_probe_unregister(struct bpf_raw_event_map *btp, struct bpf_prog *prog) | |
1553 | { | |
e16ec340 | 1554 | return tracepoint_probe_unregister(btp->tp, (void *)btp->bpf_func, prog); |
c4f6699d | 1555 | } |
41bdc4b4 YS |
1556 | |
1557 | int bpf_get_perf_event_info(const struct perf_event *event, u32 *prog_id, | |
1558 | u32 *fd_type, const char **buf, | |
1559 | u64 *probe_offset, u64 *probe_addr) | |
1560 | { | |
1561 | bool is_tracepoint, is_syscall_tp; | |
1562 | struct bpf_prog *prog; | |
1563 | int flags, err = 0; | |
1564 | ||
1565 | prog = event->prog; | |
1566 | if (!prog) | |
1567 | return -ENOENT; | |
1568 | ||
1569 | /* not supporting BPF_PROG_TYPE_PERF_EVENT yet */ | |
1570 | if (prog->type == BPF_PROG_TYPE_PERF_EVENT) | |
1571 | return -EOPNOTSUPP; | |
1572 | ||
1573 | *prog_id = prog->aux->id; | |
1574 | flags = event->tp_event->flags; | |
1575 | is_tracepoint = flags & TRACE_EVENT_FL_TRACEPOINT; | |
1576 | is_syscall_tp = is_syscall_trace_event(event->tp_event); | |
1577 | ||
1578 | if (is_tracepoint || is_syscall_tp) { | |
1579 | *buf = is_tracepoint ? event->tp_event->tp->name | |
1580 | : event->tp_event->name; | |
1581 | *fd_type = BPF_FD_TYPE_TRACEPOINT; | |
1582 | *probe_offset = 0x0; | |
1583 | *probe_addr = 0x0; | |
1584 | } else { | |
1585 | /* kprobe/uprobe */ | |
1586 | err = -EOPNOTSUPP; | |
1587 | #ifdef CONFIG_KPROBE_EVENTS | |
1588 | if (flags & TRACE_EVENT_FL_KPROBE) | |
1589 | err = bpf_get_kprobe_info(event, fd_type, buf, | |
1590 | probe_offset, probe_addr, | |
1591 | event->attr.type == PERF_TYPE_TRACEPOINT); | |
1592 | #endif | |
1593 | #ifdef CONFIG_UPROBE_EVENTS | |
1594 | if (flags & TRACE_EVENT_FL_UPROBE) | |
1595 | err = bpf_get_uprobe_info(event, fd_type, buf, | |
1596 | probe_offset, | |
1597 | event->attr.type == PERF_TYPE_TRACEPOINT); | |
1598 | #endif | |
1599 | } | |
1600 | ||
1601 | return err; | |
1602 | } | |
a38d1107 | 1603 | |
9db1ff0a YS |
1604 | static int __init send_signal_irq_work_init(void) |
1605 | { | |
1606 | int cpu; | |
1607 | struct send_signal_irq_work *work; | |
1608 | ||
1609 | for_each_possible_cpu(cpu) { | |
1610 | work = per_cpu_ptr(&send_signal_work, cpu); | |
1611 | init_irq_work(&work->irq_work, do_bpf_send_signal); | |
1612 | } | |
1613 | return 0; | |
1614 | } | |
1615 | ||
1616 | subsys_initcall(send_signal_irq_work_init); | |
1617 | ||
a38d1107 | 1618 | #ifdef CONFIG_MODULES |
390e99cf SF |
1619 | static int bpf_event_notify(struct notifier_block *nb, unsigned long op, |
1620 | void *module) | |
a38d1107 MM |
1621 | { |
1622 | struct bpf_trace_module *btm, *tmp; | |
1623 | struct module *mod = module; | |
1624 | ||
1625 | if (mod->num_bpf_raw_events == 0 || | |
1626 | (op != MODULE_STATE_COMING && op != MODULE_STATE_GOING)) | |
1627 | return 0; | |
1628 | ||
1629 | mutex_lock(&bpf_module_mutex); | |
1630 | ||
1631 | switch (op) { | |
1632 | case MODULE_STATE_COMING: | |
1633 | btm = kzalloc(sizeof(*btm), GFP_KERNEL); | |
1634 | if (btm) { | |
1635 | btm->module = module; | |
1636 | list_add(&btm->list, &bpf_trace_modules); | |
1637 | } | |
1638 | break; | |
1639 | case MODULE_STATE_GOING: | |
1640 | list_for_each_entry_safe(btm, tmp, &bpf_trace_modules, list) { | |
1641 | if (btm->module == module) { | |
1642 | list_del(&btm->list); | |
1643 | kfree(btm); | |
1644 | break; | |
1645 | } | |
1646 | } | |
1647 | break; | |
1648 | } | |
1649 | ||
1650 | mutex_unlock(&bpf_module_mutex); | |
1651 | ||
1652 | return 0; | |
1653 | } | |
1654 | ||
1655 | static struct notifier_block bpf_module_nb = { | |
1656 | .notifier_call = bpf_event_notify, | |
1657 | }; | |
1658 | ||
390e99cf | 1659 | static int __init bpf_event_init(void) |
a38d1107 MM |
1660 | { |
1661 | register_module_notifier(&bpf_module_nb); | |
1662 | return 0; | |
1663 | } | |
1664 | ||
1665 | fs_initcall(bpf_event_init); | |
1666 | #endif /* CONFIG_MODULES */ |