xref: /linux/kernel/trace/bpf_trace.c (revision f49040c7aaa5532a1f94355ef5073c49e6b32349)
1  // SPDX-License-Identifier: GPL-2.0
2  /* Copyright (c) 2011-2015 PLUMgrid, http://plumgrid.com
3   * Copyright (c) 2016 Facebook
4   */
5  #include <linux/kernel.h>
6  #include <linux/types.h>
7  #include <linux/slab.h>
8  #include <linux/bpf.h>
9  #include <linux/bpf_verifier.h>
10  #include <linux/bpf_perf_event.h>
11  #include <linux/btf.h>
12  #include <linux/filter.h>
13  #include <linux/uaccess.h>
14  #include <linux/ctype.h>
15  #include <linux/kprobes.h>
16  #include <linux/spinlock.h>
17  #include <linux/syscalls.h>
18  #include <linux/error-injection.h>
19  #include <linux/btf_ids.h>
20  #include <linux/bpf_lsm.h>
21  #include <linux/fprobe.h>
22  #include <linux/bsearch.h>
23  #include <linux/sort.h>
24  #include <linux/key.h>
25  #include <linux/verification.h>
26  #include <linux/namei.h>
27  
28  #include <net/bpf_sk_storage.h>
29  
30  #include <uapi/linux/bpf.h>
31  #include <uapi/linux/btf.h>
32  
33  #include <asm/tlb.h>
34  
35  #include "trace_probe.h"
36  #include "trace.h"
37  
38  #define CREATE_TRACE_POINTS
39  #include "bpf_trace.h"
40  
41  #define bpf_event_rcu_dereference(p)					\
42  	rcu_dereference_protected(p, lockdep_is_held(&bpf_event_mutex))
43  
44  #define MAX_UPROBE_MULTI_CNT (1U << 20)
45  #define MAX_KPROBE_MULTI_CNT (1U << 20)
46  
47  #ifdef CONFIG_MODULES
48  struct bpf_trace_module {
49  	struct module *module;
50  	struct list_head list;
51  };
52  
53  static LIST_HEAD(bpf_trace_modules);
54  static DEFINE_MUTEX(bpf_module_mutex);
55  
bpf_get_raw_tracepoint_module(const char * name)56  static struct bpf_raw_event_map *bpf_get_raw_tracepoint_module(const char *name)
57  {
58  	struct bpf_raw_event_map *btp, *ret = NULL;
59  	struct bpf_trace_module *btm;
60  	unsigned int i;
61  
62  	mutex_lock(&bpf_module_mutex);
63  	list_for_each_entry(btm, &bpf_trace_modules, list) {
64  		for (i = 0; i < btm->module->num_bpf_raw_events; ++i) {
65  			btp = &btm->module->bpf_raw_events[i];
66  			if (!strcmp(btp->tp->name, name)) {
67  				if (try_module_get(btm->module))
68  					ret = btp;
69  				goto out;
70  			}
71  		}
72  	}
73  out:
74  	mutex_unlock(&bpf_module_mutex);
75  	return ret;
76  }
77  #else
bpf_get_raw_tracepoint_module(const char * name)78  static struct bpf_raw_event_map *bpf_get_raw_tracepoint_module(const char *name)
79  {
80  	return NULL;
81  }
82  #endif /* CONFIG_MODULES */
83  
84  u64 bpf_get_stackid(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5);
85  u64 bpf_get_stack(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5);
86  
87  static int bpf_btf_printf_prepare(struct btf_ptr *ptr, u32 btf_ptr_size,
88  				  u64 flags, const struct btf **btf,
89  				  s32 *btf_id);
90  static u64 bpf_kprobe_multi_cookie(struct bpf_run_ctx *ctx);
91  static u64 bpf_kprobe_multi_entry_ip(struct bpf_run_ctx *ctx);
92  
93  static u64 bpf_uprobe_multi_cookie(struct bpf_run_ctx *ctx);
94  static u64 bpf_uprobe_multi_entry_ip(struct bpf_run_ctx *ctx);
95  
96  /**
97   * trace_call_bpf - invoke BPF program
98   * @call: tracepoint event
99   * @ctx: opaque context pointer
100   *
101   * kprobe handlers execute BPF programs via this helper.
102   * Can be used from static tracepoints in the future.
103   *
104   * Return: BPF programs always return an integer which is interpreted by
105   * kprobe handler as:
106   * 0 - return from kprobe (event is filtered out)
107   * 1 - store kprobe event into ring buffer
108   * Other values are reserved and currently alias to 1
109   */
trace_call_bpf(struct trace_event_call * call,void * ctx)110  unsigned int trace_call_bpf(struct trace_event_call *call, void *ctx)
111  {
112  	unsigned int ret;
113  
114  	cant_sleep();
115  
116  	if (unlikely(__this_cpu_inc_return(bpf_prog_active) != 1)) {
117  		/*
118  		 * since some bpf program is already running on this cpu,
119  		 * don't call into another bpf program (same or different)
120  		 * and don't send kprobe event into ring-buffer,
121  		 * so return zero here
122  		 */
123  		rcu_read_lock();
124  		bpf_prog_inc_misses_counters(rcu_dereference(call->prog_array));
125  		rcu_read_unlock();
126  		ret = 0;
127  		goto out;
128  	}
129  
130  	/*
131  	 * Instead of moving rcu_read_lock/rcu_dereference/rcu_read_unlock
132  	 * to all call sites, we did a bpf_prog_array_valid() there to check
133  	 * whether call->prog_array is empty or not, which is
134  	 * a heuristic to speed up execution.
135  	 *
136  	 * If bpf_prog_array_valid() fetched prog_array was
137  	 * non-NULL, we go into trace_call_bpf() and do the actual
138  	 * proper rcu_dereference() under RCU lock.
139  	 * If it turns out that prog_array is NULL then, we bail out.
140  	 * For the opposite, if the bpf_prog_array_valid() fetched pointer
141  	 * was NULL, you'll skip the prog_array with the risk of missing
142  	 * out of events when it was updated in between this and the
143  	 * rcu_dereference() which is accepted risk.
144  	 */
145  	rcu_read_lock();
146  	ret = bpf_prog_run_array(rcu_dereference(call->prog_array),
147  				 ctx, bpf_prog_run);
148  	rcu_read_unlock();
149  
150   out:
151  	__this_cpu_dec(bpf_prog_active);
152  
153  	return ret;
154  }
155  
156  #ifdef CONFIG_BPF_KPROBE_OVERRIDE
BPF_CALL_2(bpf_override_return,struct pt_regs *,regs,unsigned long,rc)157  BPF_CALL_2(bpf_override_return, struct pt_regs *, regs, unsigned long, rc)
158  {
159  	regs_set_return_value(regs, rc);
160  	override_function_with_return(regs);
161  	return 0;
162  }
163  
164  static const struct bpf_func_proto bpf_override_return_proto = {
165  	.func		= bpf_override_return,
166  	.gpl_only	= true,
167  	.ret_type	= RET_INTEGER,
168  	.arg1_type	= ARG_PTR_TO_CTX,
169  	.arg2_type	= ARG_ANYTHING,
170  };
171  #endif
172  
173  static __always_inline int
bpf_probe_read_user_common(void * dst,u32 size,const void __user * unsafe_ptr)174  bpf_probe_read_user_common(void *dst, u32 size, const void __user *unsafe_ptr)
175  {
176  	int ret;
177  
178  	ret = copy_from_user_nofault(dst, unsafe_ptr, size);
179  	if (unlikely(ret < 0))
180  		memset(dst, 0, size);
181  	return ret;
182  }
183  
BPF_CALL_3(bpf_probe_read_user,void *,dst,u32,size,const void __user *,unsafe_ptr)184  BPF_CALL_3(bpf_probe_read_user, void *, dst, u32, size,
185  	   const void __user *, unsafe_ptr)
186  {
187  	return bpf_probe_read_user_common(dst, size, unsafe_ptr);
188  }
189  
190  const struct bpf_func_proto bpf_probe_read_user_proto = {
191  	.func		= bpf_probe_read_user,
192  	.gpl_only	= true,
193  	.ret_type	= RET_INTEGER,
194  	.arg1_type	= ARG_PTR_TO_UNINIT_MEM,
195  	.arg2_type	= ARG_CONST_SIZE_OR_ZERO,
196  	.arg3_type	= ARG_ANYTHING,
197  };
198  
199  static __always_inline int
bpf_probe_read_user_str_common(void * dst,u32 size,const void __user * unsafe_ptr)200  bpf_probe_read_user_str_common(void *dst, u32 size,
201  			       const void __user *unsafe_ptr)
202  {
203  	int ret;
204  
205  	/*
206  	 * NB: We rely on strncpy_from_user() not copying junk past the NUL
207  	 * terminator into `dst`.
208  	 *
209  	 * strncpy_from_user() does long-sized strides in the fast path. If the
210  	 * strncpy does not mask out the bytes after the NUL in `unsafe_ptr`,
211  	 * then there could be junk after the NUL in `dst`. If user takes `dst`
212  	 * and keys a hash map with it, then semantically identical strings can
213  	 * occupy multiple entries in the map.
214  	 */
215  	ret = strncpy_from_user_nofault(dst, unsafe_ptr, size);
216  	if (unlikely(ret < 0))
217  		memset(dst, 0, size);
218  	return ret;
219  }
220  
BPF_CALL_3(bpf_probe_read_user_str,void *,dst,u32,size,const void __user *,unsafe_ptr)221  BPF_CALL_3(bpf_probe_read_user_str, void *, dst, u32, size,
222  	   const void __user *, unsafe_ptr)
223  {
224  	return bpf_probe_read_user_str_common(dst, size, unsafe_ptr);
225  }
226  
227  const struct bpf_func_proto bpf_probe_read_user_str_proto = {
228  	.func		= bpf_probe_read_user_str,
229  	.gpl_only	= true,
230  	.ret_type	= RET_INTEGER,
231  	.arg1_type	= ARG_PTR_TO_UNINIT_MEM,
232  	.arg2_type	= ARG_CONST_SIZE_OR_ZERO,
233  	.arg3_type	= ARG_ANYTHING,
234  };
235  
BPF_CALL_3(bpf_probe_read_kernel,void *,dst,u32,size,const void *,unsafe_ptr)236  BPF_CALL_3(bpf_probe_read_kernel, void *, dst, u32, size,
237  	   const void *, unsafe_ptr)
238  {
239  	return bpf_probe_read_kernel_common(dst, size, unsafe_ptr);
240  }
241  
242  const struct bpf_func_proto bpf_probe_read_kernel_proto = {
243  	.func		= bpf_probe_read_kernel,
244  	.gpl_only	= true,
245  	.ret_type	= RET_INTEGER,
246  	.arg1_type	= ARG_PTR_TO_UNINIT_MEM,
247  	.arg2_type	= ARG_CONST_SIZE_OR_ZERO,
248  	.arg3_type	= ARG_ANYTHING,
249  };
250  
251  static __always_inline int
bpf_probe_read_kernel_str_common(void * dst,u32 size,const void * unsafe_ptr)252  bpf_probe_read_kernel_str_common(void *dst, u32 size, const void *unsafe_ptr)
253  {
254  	int ret;
255  
256  	/*
257  	 * The strncpy_from_kernel_nofault() call will likely not fill the
258  	 * entire buffer, but that's okay in this circumstance as we're probing
259  	 * arbitrary memory anyway similar to bpf_probe_read_*() and might
260  	 * as well probe the stack. Thus, memory is explicitly cleared
261  	 * only in error case, so that improper users ignoring return
262  	 * code altogether don't copy garbage; otherwise length of string
263  	 * is returned that can be used for bpf_perf_event_output() et al.
264  	 */
265  	ret = strncpy_from_kernel_nofault(dst, unsafe_ptr, size);
266  	if (unlikely(ret < 0))
267  		memset(dst, 0, size);
268  	return ret;
269  }
270  
BPF_CALL_3(bpf_probe_read_kernel_str,void *,dst,u32,size,const void *,unsafe_ptr)271  BPF_CALL_3(bpf_probe_read_kernel_str, void *, dst, u32, size,
272  	   const void *, unsafe_ptr)
273  {
274  	return bpf_probe_read_kernel_str_common(dst, size, unsafe_ptr);
275  }
276  
277  const struct bpf_func_proto bpf_probe_read_kernel_str_proto = {
278  	.func		= bpf_probe_read_kernel_str,
279  	.gpl_only	= true,
280  	.ret_type	= RET_INTEGER,
281  	.arg1_type	= ARG_PTR_TO_UNINIT_MEM,
282  	.arg2_type	= ARG_CONST_SIZE_OR_ZERO,
283  	.arg3_type	= ARG_ANYTHING,
284  };
285  
286  #ifdef CONFIG_ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE
BPF_CALL_3(bpf_probe_read_compat,void *,dst,u32,size,const void *,unsafe_ptr)287  BPF_CALL_3(bpf_probe_read_compat, void *, dst, u32, size,
288  	   const void *, unsafe_ptr)
289  {
290  	if ((unsigned long)unsafe_ptr < TASK_SIZE) {
291  		return bpf_probe_read_user_common(dst, size,
292  				(__force void __user *)unsafe_ptr);
293  	}
294  	return bpf_probe_read_kernel_common(dst, size, unsafe_ptr);
295  }
296  
297  static const struct bpf_func_proto bpf_probe_read_compat_proto = {
298  	.func		= bpf_probe_read_compat,
299  	.gpl_only	= true,
300  	.ret_type	= RET_INTEGER,
301  	.arg1_type	= ARG_PTR_TO_UNINIT_MEM,
302  	.arg2_type	= ARG_CONST_SIZE_OR_ZERO,
303  	.arg3_type	= ARG_ANYTHING,
304  };
305  
BPF_CALL_3(bpf_probe_read_compat_str,void *,dst,u32,size,const void *,unsafe_ptr)306  BPF_CALL_3(bpf_probe_read_compat_str, void *, dst, u32, size,
307  	   const void *, unsafe_ptr)
308  {
309  	if ((unsigned long)unsafe_ptr < TASK_SIZE) {
310  		return bpf_probe_read_user_str_common(dst, size,
311  				(__force void __user *)unsafe_ptr);
312  	}
313  	return bpf_probe_read_kernel_str_common(dst, size, unsafe_ptr);
314  }
315  
316  static const struct bpf_func_proto bpf_probe_read_compat_str_proto = {
317  	.func		= bpf_probe_read_compat_str,
318  	.gpl_only	= true,
319  	.ret_type	= RET_INTEGER,
320  	.arg1_type	= ARG_PTR_TO_UNINIT_MEM,
321  	.arg2_type	= ARG_CONST_SIZE_OR_ZERO,
322  	.arg3_type	= ARG_ANYTHING,
323  };
324  #endif /* CONFIG_ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE */
325  
BPF_CALL_3(bpf_probe_write_user,void __user *,unsafe_ptr,const void *,src,u32,size)326  BPF_CALL_3(bpf_probe_write_user, void __user *, unsafe_ptr, const void *, src,
327  	   u32, size)
328  {
329  	/*
330  	 * Ensure we're in user context which is safe for the helper to
331  	 * run. This helper has no business in a kthread.
332  	 *
333  	 * access_ok() should prevent writing to non-user memory, but in
334  	 * some situations (nommu, temporary switch, etc) access_ok() does
335  	 * not provide enough validation, hence the check on KERNEL_DS.
336  	 *
337  	 * nmi_uaccess_okay() ensures the probe is not run in an interim
338  	 * state, when the task or mm are switched. This is specifically
339  	 * required to prevent the use of temporary mm.
340  	 */
341  
342  	if (unlikely(in_interrupt() ||
343  		     current->flags & (PF_KTHREAD | PF_EXITING)))
344  		return -EPERM;
345  	if (unlikely(!nmi_uaccess_okay()))
346  		return -EPERM;
347  
348  	return copy_to_user_nofault(unsafe_ptr, src, size);
349  }
350  
351  static const struct bpf_func_proto bpf_probe_write_user_proto = {
352  	.func		= bpf_probe_write_user,
353  	.gpl_only	= true,
354  	.ret_type	= RET_INTEGER,
355  	.arg1_type	= ARG_ANYTHING,
356  	.arg2_type	= ARG_PTR_TO_MEM | MEM_RDONLY,
357  	.arg3_type	= ARG_CONST_SIZE,
358  };
359  
360  #define MAX_TRACE_PRINTK_VARARGS	3
361  #define BPF_TRACE_PRINTK_SIZE		1024
362  
BPF_CALL_5(bpf_trace_printk,char *,fmt,u32,fmt_size,u64,arg1,u64,arg2,u64,arg3)363  BPF_CALL_5(bpf_trace_printk, char *, fmt, u32, fmt_size, u64, arg1,
364  	   u64, arg2, u64, arg3)
365  {
366  	u64 args[MAX_TRACE_PRINTK_VARARGS] = { arg1, arg2, arg3 };
367  	struct bpf_bprintf_data data = {
368  		.get_bin_args	= true,
369  		.get_buf	= true,
370  	};
371  	int ret;
372  
373  	ret = bpf_bprintf_prepare(fmt, fmt_size, args,
374  				  MAX_TRACE_PRINTK_VARARGS, &data);
375  	if (ret < 0)
376  		return ret;
377  
378  	ret = bstr_printf(data.buf, MAX_BPRINTF_BUF, fmt, data.bin_args);
379  
380  	trace_bpf_trace_printk(data.buf);
381  
382  	bpf_bprintf_cleanup(&data);
383  
384  	return ret;
385  }
386  
387  static const struct bpf_func_proto bpf_trace_printk_proto = {
388  	.func		= bpf_trace_printk,
389  	.gpl_only	= true,
390  	.ret_type	= RET_INTEGER,
391  	.arg1_type	= ARG_PTR_TO_MEM | MEM_RDONLY,
392  	.arg2_type	= ARG_CONST_SIZE,
393  };
394  
__set_printk_clr_event(void)395  static void __set_printk_clr_event(void)
396  {
397  	/*
398  	 * This program might be calling bpf_trace_printk,
399  	 * so enable the associated bpf_trace/bpf_trace_printk event.
400  	 * Repeat this each time as it is possible a user has
401  	 * disabled bpf_trace_printk events.  By loading a program
402  	 * calling bpf_trace_printk() however the user has expressed
403  	 * the intent to see such events.
404  	 */
405  	if (trace_set_clr_event("bpf_trace", "bpf_trace_printk", 1))
406  		pr_warn_ratelimited("could not enable bpf_trace_printk events");
407  }
408  
bpf_get_trace_printk_proto(void)409  const struct bpf_func_proto *bpf_get_trace_printk_proto(void)
410  {
411  	__set_printk_clr_event();
412  	return &bpf_trace_printk_proto;
413  }
414  
BPF_CALL_4(bpf_trace_vprintk,char *,fmt,u32,fmt_size,const void *,args,u32,data_len)415  BPF_CALL_4(bpf_trace_vprintk, char *, fmt, u32, fmt_size, const void *, args,
416  	   u32, data_len)
417  {
418  	struct bpf_bprintf_data data = {
419  		.get_bin_args	= true,
420  		.get_buf	= true,
421  	};
422  	int ret, num_args;
423  
424  	if (data_len & 7 || data_len > MAX_BPRINTF_VARARGS * 8 ||
425  	    (data_len && !args))
426  		return -EINVAL;
427  	num_args = data_len / 8;
428  
429  	ret = bpf_bprintf_prepare(fmt, fmt_size, args, num_args, &data);
430  	if (ret < 0)
431  		return ret;
432  
433  	ret = bstr_printf(data.buf, MAX_BPRINTF_BUF, fmt, data.bin_args);
434  
435  	trace_bpf_trace_printk(data.buf);
436  
437  	bpf_bprintf_cleanup(&data);
438  
439  	return ret;
440  }
441  
442  static const struct bpf_func_proto bpf_trace_vprintk_proto = {
443  	.func		= bpf_trace_vprintk,
444  	.gpl_only	= true,
445  	.ret_type	= RET_INTEGER,
446  	.arg1_type	= ARG_PTR_TO_MEM | MEM_RDONLY,
447  	.arg2_type	= ARG_CONST_SIZE,
448  	.arg3_type	= ARG_PTR_TO_MEM | PTR_MAYBE_NULL | MEM_RDONLY,
449  	.arg4_type	= ARG_CONST_SIZE_OR_ZERO,
450  };
451  
bpf_get_trace_vprintk_proto(void)452  const struct bpf_func_proto *bpf_get_trace_vprintk_proto(void)
453  {
454  	__set_printk_clr_event();
455  	return &bpf_trace_vprintk_proto;
456  }
457  
BPF_CALL_5(bpf_seq_printf,struct seq_file *,m,char *,fmt,u32,fmt_size,const void *,args,u32,data_len)458  BPF_CALL_5(bpf_seq_printf, struct seq_file *, m, char *, fmt, u32, fmt_size,
459  	   const void *, args, u32, data_len)
460  {
461  	struct bpf_bprintf_data data = {
462  		.get_bin_args	= true,
463  	};
464  	int err, num_args;
465  
466  	if (data_len & 7 || data_len > MAX_BPRINTF_VARARGS * 8 ||
467  	    (data_len && !args))
468  		return -EINVAL;
469  	num_args = data_len / 8;
470  
471  	err = bpf_bprintf_prepare(fmt, fmt_size, args, num_args, &data);
472  	if (err < 0)
473  		return err;
474  
475  	seq_bprintf(m, fmt, data.bin_args);
476  
477  	bpf_bprintf_cleanup(&data);
478  
479  	return seq_has_overflowed(m) ? -EOVERFLOW : 0;
480  }
481  
482  BTF_ID_LIST_SINGLE(btf_seq_file_ids, struct, seq_file)
483  
484  static const struct bpf_func_proto bpf_seq_printf_proto = {
485  	.func		= bpf_seq_printf,
486  	.gpl_only	= true,
487  	.ret_type	= RET_INTEGER,
488  	.arg1_type	= ARG_PTR_TO_BTF_ID,
489  	.arg1_btf_id	= &btf_seq_file_ids[0],
490  	.arg2_type	= ARG_PTR_TO_MEM | MEM_RDONLY,
491  	.arg3_type	= ARG_CONST_SIZE,
492  	.arg4_type      = ARG_PTR_TO_MEM | PTR_MAYBE_NULL | MEM_RDONLY,
493  	.arg5_type      = ARG_CONST_SIZE_OR_ZERO,
494  };
495  
BPF_CALL_3(bpf_seq_write,struct seq_file *,m,const void *,data,u32,len)496  BPF_CALL_3(bpf_seq_write, struct seq_file *, m, const void *, data, u32, len)
497  {
498  	return seq_write(m, data, len) ? -EOVERFLOW : 0;
499  }
500  
501  static const struct bpf_func_proto bpf_seq_write_proto = {
502  	.func		= bpf_seq_write,
503  	.gpl_only	= true,
504  	.ret_type	= RET_INTEGER,
505  	.arg1_type	= ARG_PTR_TO_BTF_ID,
506  	.arg1_btf_id	= &btf_seq_file_ids[0],
507  	.arg2_type	= ARG_PTR_TO_MEM | MEM_RDONLY,
508  	.arg3_type	= ARG_CONST_SIZE_OR_ZERO,
509  };
510  
BPF_CALL_4(bpf_seq_printf_btf,struct seq_file *,m,struct btf_ptr *,ptr,u32,btf_ptr_size,u64,flags)511  BPF_CALL_4(bpf_seq_printf_btf, struct seq_file *, m, struct btf_ptr *, ptr,
512  	   u32, btf_ptr_size, u64, flags)
513  {
514  	const struct btf *btf;
515  	s32 btf_id;
516  	int ret;
517  
518  	ret = bpf_btf_printf_prepare(ptr, btf_ptr_size, flags, &btf, &btf_id);
519  	if (ret)
520  		return ret;
521  
522  	return btf_type_seq_show_flags(btf, btf_id, ptr->ptr, m, flags);
523  }
524  
525  static const struct bpf_func_proto bpf_seq_printf_btf_proto = {
526  	.func		= bpf_seq_printf_btf,
527  	.gpl_only	= true,
528  	.ret_type	= RET_INTEGER,
529  	.arg1_type	= ARG_PTR_TO_BTF_ID,
530  	.arg1_btf_id	= &btf_seq_file_ids[0],
531  	.arg2_type	= ARG_PTR_TO_MEM | MEM_RDONLY,
532  	.arg3_type	= ARG_CONST_SIZE_OR_ZERO,
533  	.arg4_type	= ARG_ANYTHING,
534  };
535  
536  static __always_inline int
get_map_perf_counter(struct bpf_map * map,u64 flags,u64 * value,u64 * enabled,u64 * running)537  get_map_perf_counter(struct bpf_map *map, u64 flags,
538  		     u64 *value, u64 *enabled, u64 *running)
539  {
540  	struct bpf_array *array = container_of(map, struct bpf_array, map);
541  	unsigned int cpu = smp_processor_id();
542  	u64 index = flags & BPF_F_INDEX_MASK;
543  	struct bpf_event_entry *ee;
544  
545  	if (unlikely(flags & ~(BPF_F_INDEX_MASK)))
546  		return -EINVAL;
547  	if (index == BPF_F_CURRENT_CPU)
548  		index = cpu;
549  	if (unlikely(index >= array->map.max_entries))
550  		return -E2BIG;
551  
552  	ee = READ_ONCE(array->ptrs[index]);
553  	if (!ee)
554  		return -ENOENT;
555  
556  	return perf_event_read_local(ee->event, value, enabled, running);
557  }
558  
BPF_CALL_2(bpf_perf_event_read,struct bpf_map *,map,u64,flags)559  BPF_CALL_2(bpf_perf_event_read, struct bpf_map *, map, u64, flags)
560  {
561  	u64 value = 0;
562  	int err;
563  
564  	err = get_map_perf_counter(map, flags, &value, NULL, NULL);
565  	/*
566  	 * this api is ugly since we miss [-22..-2] range of valid
567  	 * counter values, but that's uapi
568  	 */
569  	if (err)
570  		return err;
571  	return value;
572  }
573  
574  static const struct bpf_func_proto bpf_perf_event_read_proto = {
575  	.func		= bpf_perf_event_read,
576  	.gpl_only	= true,
577  	.ret_type	= RET_INTEGER,
578  	.arg1_type	= ARG_CONST_MAP_PTR,
579  	.arg2_type	= ARG_ANYTHING,
580  };
581  
BPF_CALL_4(bpf_perf_event_read_value,struct bpf_map *,map,u64,flags,struct bpf_perf_event_value *,buf,u32,size)582  BPF_CALL_4(bpf_perf_event_read_value, struct bpf_map *, map, u64, flags,
583  	   struct bpf_perf_event_value *, buf, u32, size)
584  {
585  	int err = -EINVAL;
586  
587  	if (unlikely(size != sizeof(struct bpf_perf_event_value)))
588  		goto clear;
589  	err = get_map_perf_counter(map, flags, &buf->counter, &buf->enabled,
590  				   &buf->running);
591  	if (unlikely(err))
592  		goto clear;
593  	return 0;
594  clear:
595  	memset(buf, 0, size);
596  	return err;
597  }
598  
599  static const struct bpf_func_proto bpf_perf_event_read_value_proto = {
600  	.func		= bpf_perf_event_read_value,
601  	.gpl_only	= true,
602  	.ret_type	= RET_INTEGER,
603  	.arg1_type	= ARG_CONST_MAP_PTR,
604  	.arg2_type	= ARG_ANYTHING,
605  	.arg3_type	= ARG_PTR_TO_UNINIT_MEM,
606  	.arg4_type	= ARG_CONST_SIZE,
607  };
608  
609  static __always_inline u64
__bpf_perf_event_output(struct pt_regs * regs,struct bpf_map * map,u64 flags,struct perf_raw_record * raw,struct perf_sample_data * sd)610  __bpf_perf_event_output(struct pt_regs *regs, struct bpf_map *map,
611  			u64 flags, struct perf_raw_record *raw,
612  			struct perf_sample_data *sd)
613  {
614  	struct bpf_array *array = container_of(map, struct bpf_array, map);
615  	unsigned int cpu = smp_processor_id();
616  	u64 index = flags & BPF_F_INDEX_MASK;
617  	struct bpf_event_entry *ee;
618  	struct perf_event *event;
619  
620  	if (index == BPF_F_CURRENT_CPU)
621  		index = cpu;
622  	if (unlikely(index >= array->map.max_entries))
623  		return -E2BIG;
624  
625  	ee = READ_ONCE(array->ptrs[index]);
626  	if (!ee)
627  		return -ENOENT;
628  
629  	event = ee->event;
630  	if (unlikely(event->attr.type != PERF_TYPE_SOFTWARE ||
631  		     event->attr.config != PERF_COUNT_SW_BPF_OUTPUT))
632  		return -EINVAL;
633  
634  	if (unlikely(event->oncpu != cpu))
635  		return -EOPNOTSUPP;
636  
637  	perf_sample_save_raw_data(sd, event, raw);
638  
639  	return perf_event_output(event, sd, regs);
640  }
641  
642  /*
643   * Support executing tracepoints in normal, irq, and nmi context that each call
644   * bpf_perf_event_output
645   */
646  struct bpf_trace_sample_data {
647  	struct perf_sample_data sds[3];
648  };
649  
650  static DEFINE_PER_CPU(struct bpf_trace_sample_data, bpf_trace_sds);
651  static DEFINE_PER_CPU(int, bpf_trace_nest_level);
BPF_CALL_5(bpf_perf_event_output,struct pt_regs *,regs,struct bpf_map *,map,u64,flags,void *,data,u64,size)652  BPF_CALL_5(bpf_perf_event_output, struct pt_regs *, regs, struct bpf_map *, map,
653  	   u64, flags, void *, data, u64, size)
654  {
655  	struct bpf_trace_sample_data *sds;
656  	struct perf_raw_record raw = {
657  		.frag = {
658  			.size = size,
659  			.data = data,
660  		},
661  	};
662  	struct perf_sample_data *sd;
663  	int nest_level, err;
664  
665  	preempt_disable();
666  	sds = this_cpu_ptr(&bpf_trace_sds);
667  	nest_level = this_cpu_inc_return(bpf_trace_nest_level);
668  
669  	if (WARN_ON_ONCE(nest_level > ARRAY_SIZE(sds->sds))) {
670  		err = -EBUSY;
671  		goto out;
672  	}
673  
674  	sd = &sds->sds[nest_level - 1];
675  
676  	if (unlikely(flags & ~(BPF_F_INDEX_MASK))) {
677  		err = -EINVAL;
678  		goto out;
679  	}
680  
681  	perf_sample_data_init(sd, 0, 0);
682  
683  	err = __bpf_perf_event_output(regs, map, flags, &raw, sd);
684  out:
685  	this_cpu_dec(bpf_trace_nest_level);
686  	preempt_enable();
687  	return err;
688  }
689  
690  static const struct bpf_func_proto bpf_perf_event_output_proto = {
691  	.func		= bpf_perf_event_output,
692  	.gpl_only	= true,
693  	.ret_type	= RET_INTEGER,
694  	.arg1_type	= ARG_PTR_TO_CTX,
695  	.arg2_type	= ARG_CONST_MAP_PTR,
696  	.arg3_type	= ARG_ANYTHING,
697  	.arg4_type	= ARG_PTR_TO_MEM | MEM_RDONLY,
698  	.arg5_type	= ARG_CONST_SIZE_OR_ZERO,
699  };
700  
701  static DEFINE_PER_CPU(int, bpf_event_output_nest_level);
702  struct bpf_nested_pt_regs {
703  	struct pt_regs regs[3];
704  };
705  static DEFINE_PER_CPU(struct bpf_nested_pt_regs, bpf_pt_regs);
706  static DEFINE_PER_CPU(struct bpf_trace_sample_data, bpf_misc_sds);
707  
bpf_event_output(struct bpf_map * map,u64 flags,void * meta,u64 meta_size,void * ctx,u64 ctx_size,bpf_ctx_copy_t ctx_copy)708  u64 bpf_event_output(struct bpf_map *map, u64 flags, void *meta, u64 meta_size,
709  		     void *ctx, u64 ctx_size, bpf_ctx_copy_t ctx_copy)
710  {
711  	struct perf_raw_frag frag = {
712  		.copy		= ctx_copy,
713  		.size		= ctx_size,
714  		.data		= ctx,
715  	};
716  	struct perf_raw_record raw = {
717  		.frag = {
718  			{
719  				.next	= ctx_size ? &frag : NULL,
720  			},
721  			.size	= meta_size,
722  			.data	= meta,
723  		},
724  	};
725  	struct perf_sample_data *sd;
726  	struct pt_regs *regs;
727  	int nest_level;
728  	u64 ret;
729  
730  	preempt_disable();
731  	nest_level = this_cpu_inc_return(bpf_event_output_nest_level);
732  
733  	if (WARN_ON_ONCE(nest_level > ARRAY_SIZE(bpf_misc_sds.sds))) {
734  		ret = -EBUSY;
735  		goto out;
736  	}
737  	sd = this_cpu_ptr(&bpf_misc_sds.sds[nest_level - 1]);
738  	regs = this_cpu_ptr(&bpf_pt_regs.regs[nest_level - 1]);
739  
740  	perf_fetch_caller_regs(regs);
741  	perf_sample_data_init(sd, 0, 0);
742  
743  	ret = __bpf_perf_event_output(regs, map, flags, &raw, sd);
744  out:
745  	this_cpu_dec(bpf_event_output_nest_level);
746  	preempt_enable();
747  	return ret;
748  }
749  
BPF_CALL_0(bpf_get_current_task)750  BPF_CALL_0(bpf_get_current_task)
751  {
752  	return (long) current;
753  }
754  
755  const struct bpf_func_proto bpf_get_current_task_proto = {
756  	.func		= bpf_get_current_task,
757  	.gpl_only	= true,
758  	.ret_type	= RET_INTEGER,
759  };
760  
BPF_CALL_0(bpf_get_current_task_btf)761  BPF_CALL_0(bpf_get_current_task_btf)
762  {
763  	return (unsigned long) current;
764  }
765  
766  const struct bpf_func_proto bpf_get_current_task_btf_proto = {
767  	.func		= bpf_get_current_task_btf,
768  	.gpl_only	= true,
769  	.ret_type	= RET_PTR_TO_BTF_ID_TRUSTED,
770  	.ret_btf_id	= &btf_tracing_ids[BTF_TRACING_TYPE_TASK],
771  };
772  
BPF_CALL_1(bpf_task_pt_regs,struct task_struct *,task)773  BPF_CALL_1(bpf_task_pt_regs, struct task_struct *, task)
774  {
775  	return (unsigned long) task_pt_regs(task);
776  }
777  
778  BTF_ID_LIST(bpf_task_pt_regs_ids)
779  BTF_ID(struct, pt_regs)
780  
781  const struct bpf_func_proto bpf_task_pt_regs_proto = {
782  	.func		= bpf_task_pt_regs,
783  	.gpl_only	= true,
784  	.arg1_type	= ARG_PTR_TO_BTF_ID,
785  	.arg1_btf_id	= &btf_tracing_ids[BTF_TRACING_TYPE_TASK],
786  	.ret_type	= RET_PTR_TO_BTF_ID,
787  	.ret_btf_id	= &bpf_task_pt_regs_ids[0],
788  };
789  
790  struct send_signal_irq_work {
791  	struct irq_work irq_work;
792  	struct task_struct *task;
793  	u32 sig;
794  	enum pid_type type;
795  	bool has_siginfo;
796  	struct kernel_siginfo info;
797  };
798  
799  static DEFINE_PER_CPU(struct send_signal_irq_work, send_signal_work);
800  
do_bpf_send_signal(struct irq_work * entry)801  static void do_bpf_send_signal(struct irq_work *entry)
802  {
803  	struct send_signal_irq_work *work;
804  	struct kernel_siginfo *siginfo;
805  
806  	work = container_of(entry, struct send_signal_irq_work, irq_work);
807  	siginfo = work->has_siginfo ? &work->info : SEND_SIG_PRIV;
808  
809  	group_send_sig_info(work->sig, siginfo, work->task, work->type);
810  	put_task_struct(work->task);
811  }
812  
bpf_send_signal_common(u32 sig,enum pid_type type,struct task_struct * task,u64 value)813  static int bpf_send_signal_common(u32 sig, enum pid_type type, struct task_struct *task, u64 value)
814  {
815  	struct send_signal_irq_work *work = NULL;
816  	struct kernel_siginfo info;
817  	struct kernel_siginfo *siginfo;
818  
819  	if (!task) {
820  		task = current;
821  		siginfo = SEND_SIG_PRIV;
822  	} else {
823  		clear_siginfo(&info);
824  		info.si_signo = sig;
825  		info.si_errno = 0;
826  		info.si_code = SI_KERNEL;
827  		info.si_pid = 0;
828  		info.si_uid = 0;
829  		info.si_value.sival_ptr = (void *)(unsigned long)value;
830  		siginfo = &info;
831  	}
832  
833  	/* Similar to bpf_probe_write_user, task needs to be
834  	 * in a sound condition and kernel memory access be
835  	 * permitted in order to send signal to the current
836  	 * task.
837  	 */
838  	if (unlikely(task->flags & (PF_KTHREAD | PF_EXITING)))
839  		return -EPERM;
840  	if (unlikely(!nmi_uaccess_okay()))
841  		return -EPERM;
842  	/* Task should not be pid=1 to avoid kernel panic. */
843  	if (unlikely(is_global_init(task)))
844  		return -EPERM;
845  
846  	if (!preemptible()) {
847  		/* Do an early check on signal validity. Otherwise,
848  		 * the error is lost in deferred irq_work.
849  		 */
850  		if (unlikely(!valid_signal(sig)))
851  			return -EINVAL;
852  
853  		work = this_cpu_ptr(&send_signal_work);
854  		if (irq_work_is_busy(&work->irq_work))
855  			return -EBUSY;
856  
857  		/* Add the current task, which is the target of sending signal,
858  		 * to the irq_work. The current task may change when queued
859  		 * irq works get executed.
860  		 */
861  		work->task = get_task_struct(task);
862  		work->has_siginfo = siginfo == &info;
863  		if (work->has_siginfo)
864  			copy_siginfo(&work->info, &info);
865  		work->sig = sig;
866  		work->type = type;
867  		irq_work_queue(&work->irq_work);
868  		return 0;
869  	}
870  
871  	return group_send_sig_info(sig, siginfo, task, type);
872  }
873  
BPF_CALL_1(bpf_send_signal,u32,sig)874  BPF_CALL_1(bpf_send_signal, u32, sig)
875  {
876  	return bpf_send_signal_common(sig, PIDTYPE_TGID, NULL, 0);
877  }
878  
879  static const struct bpf_func_proto bpf_send_signal_proto = {
880  	.func		= bpf_send_signal,
881  	.gpl_only	= false,
882  	.ret_type	= RET_INTEGER,
883  	.arg1_type	= ARG_ANYTHING,
884  };
885  
BPF_CALL_1(bpf_send_signal_thread,u32,sig)886  BPF_CALL_1(bpf_send_signal_thread, u32, sig)
887  {
888  	return bpf_send_signal_common(sig, PIDTYPE_PID, NULL, 0);
889  }
890  
891  static const struct bpf_func_proto bpf_send_signal_thread_proto = {
892  	.func		= bpf_send_signal_thread,
893  	.gpl_only	= false,
894  	.ret_type	= RET_INTEGER,
895  	.arg1_type	= ARG_ANYTHING,
896  };
897  
BPF_CALL_3(bpf_d_path,struct path *,path,char *,buf,u32,sz)898  BPF_CALL_3(bpf_d_path, struct path *, path, char *, buf, u32, sz)
899  {
900  	struct path copy;
901  	long len;
902  	char *p;
903  
904  	if (!sz)
905  		return 0;
906  
907  	/*
908  	 * The path pointer is verified as trusted and safe to use,
909  	 * but let's double check it's valid anyway to workaround
910  	 * potentially broken verifier.
911  	 */
912  	len = copy_from_kernel_nofault(&copy, path, sizeof(*path));
913  	if (len < 0)
914  		return len;
915  
916  	p = d_path(&copy, buf, sz);
917  	if (IS_ERR(p)) {
918  		len = PTR_ERR(p);
919  	} else {
920  		len = buf + sz - p;
921  		memmove(buf, p, len);
922  	}
923  
924  	return len;
925  }
926  
927  BTF_SET_START(btf_allowlist_d_path)
928  #ifdef CONFIG_SECURITY
BTF_ID(func,security_file_permission)929  BTF_ID(func, security_file_permission)
930  BTF_ID(func, security_inode_getattr)
931  BTF_ID(func, security_file_open)
932  #endif
933  #ifdef CONFIG_SECURITY_PATH
934  BTF_ID(func, security_path_truncate)
935  #endif
936  BTF_ID(func, vfs_truncate)
937  BTF_ID(func, vfs_fallocate)
938  BTF_ID(func, dentry_open)
939  BTF_ID(func, vfs_getattr)
940  BTF_ID(func, filp_close)
941  BTF_SET_END(btf_allowlist_d_path)
942  
943  static bool bpf_d_path_allowed(const struct bpf_prog *prog)
944  {
945  	if (prog->type == BPF_PROG_TYPE_TRACING &&
946  	    prog->expected_attach_type == BPF_TRACE_ITER)
947  		return true;
948  
949  	if (prog->type == BPF_PROG_TYPE_LSM)
950  		return bpf_lsm_is_sleepable_hook(prog->aux->attach_btf_id);
951  
952  	return btf_id_set_contains(&btf_allowlist_d_path,
953  				   prog->aux->attach_btf_id);
954  }
955  
956  BTF_ID_LIST_SINGLE(bpf_d_path_btf_ids, struct, path)
957  
958  static const struct bpf_func_proto bpf_d_path_proto = {
959  	.func		= bpf_d_path,
960  	.gpl_only	= false,
961  	.ret_type	= RET_INTEGER,
962  	.arg1_type	= ARG_PTR_TO_BTF_ID,
963  	.arg1_btf_id	= &bpf_d_path_btf_ids[0],
964  	.arg2_type	= ARG_PTR_TO_MEM,
965  	.arg3_type	= ARG_CONST_SIZE_OR_ZERO,
966  	.allowed	= bpf_d_path_allowed,
967  };
968  
969  #define BTF_F_ALL	(BTF_F_COMPACT  | BTF_F_NONAME | \
970  			 BTF_F_PTR_RAW | BTF_F_ZERO)
971  
bpf_btf_printf_prepare(struct btf_ptr * ptr,u32 btf_ptr_size,u64 flags,const struct btf ** btf,s32 * btf_id)972  static int bpf_btf_printf_prepare(struct btf_ptr *ptr, u32 btf_ptr_size,
973  				  u64 flags, const struct btf **btf,
974  				  s32 *btf_id)
975  {
976  	const struct btf_type *t;
977  
978  	if (unlikely(flags & ~(BTF_F_ALL)))
979  		return -EINVAL;
980  
981  	if (btf_ptr_size != sizeof(struct btf_ptr))
982  		return -EINVAL;
983  
984  	*btf = bpf_get_btf_vmlinux();
985  
986  	if (IS_ERR_OR_NULL(*btf))
987  		return IS_ERR(*btf) ? PTR_ERR(*btf) : -EINVAL;
988  
989  	if (ptr->type_id > 0)
990  		*btf_id = ptr->type_id;
991  	else
992  		return -EINVAL;
993  
994  	if (*btf_id > 0)
995  		t = btf_type_by_id(*btf, *btf_id);
996  	if (*btf_id <= 0 || !t)
997  		return -ENOENT;
998  
999  	return 0;
1000  }
1001  
BPF_CALL_5(bpf_snprintf_btf,char *,str,u32,str_size,struct btf_ptr *,ptr,u32,btf_ptr_size,u64,flags)1002  BPF_CALL_5(bpf_snprintf_btf, char *, str, u32, str_size, struct btf_ptr *, ptr,
1003  	   u32, btf_ptr_size, u64, flags)
1004  {
1005  	const struct btf *btf;
1006  	s32 btf_id;
1007  	int ret;
1008  
1009  	ret = bpf_btf_printf_prepare(ptr, btf_ptr_size, flags, &btf, &btf_id);
1010  	if (ret)
1011  		return ret;
1012  
1013  	return btf_type_snprintf_show(btf, btf_id, ptr->ptr, str, str_size,
1014  				      flags);
1015  }
1016  
1017  const struct bpf_func_proto bpf_snprintf_btf_proto = {
1018  	.func		= bpf_snprintf_btf,
1019  	.gpl_only	= false,
1020  	.ret_type	= RET_INTEGER,
1021  	.arg1_type	= ARG_PTR_TO_MEM,
1022  	.arg2_type	= ARG_CONST_SIZE,
1023  	.arg3_type	= ARG_PTR_TO_MEM | MEM_RDONLY,
1024  	.arg4_type	= ARG_CONST_SIZE,
1025  	.arg5_type	= ARG_ANYTHING,
1026  };
1027  
BPF_CALL_1(bpf_get_func_ip_tracing,void *,ctx)1028  BPF_CALL_1(bpf_get_func_ip_tracing, void *, ctx)
1029  {
1030  	/* This helper call is inlined by verifier. */
1031  	return ((u64 *)ctx)[-2];
1032  }
1033  
1034  static const struct bpf_func_proto bpf_get_func_ip_proto_tracing = {
1035  	.func		= bpf_get_func_ip_tracing,
1036  	.gpl_only	= true,
1037  	.ret_type	= RET_INTEGER,
1038  	.arg1_type	= ARG_PTR_TO_CTX,
1039  };
1040  
get_entry_ip(unsigned long fentry_ip)1041  static inline unsigned long get_entry_ip(unsigned long fentry_ip)
1042  {
1043  #ifdef CONFIG_X86_KERNEL_IBT
1044  	if (is_endbr((void *)(fentry_ip - ENDBR_INSN_SIZE)))
1045  		fentry_ip -= ENDBR_INSN_SIZE;
1046  #endif
1047  	return fentry_ip;
1048  }
1049  
BPF_CALL_1(bpf_get_func_ip_kprobe,struct pt_regs *,regs)1050  BPF_CALL_1(bpf_get_func_ip_kprobe, struct pt_regs *, regs)
1051  {
1052  	struct bpf_trace_run_ctx *run_ctx __maybe_unused;
1053  	struct kprobe *kp;
1054  
1055  #ifdef CONFIG_UPROBES
1056  	run_ctx = container_of(current->bpf_ctx, struct bpf_trace_run_ctx, run_ctx);
1057  	if (run_ctx->is_uprobe)
1058  		return ((struct uprobe_dispatch_data *)current->utask->vaddr)->bp_addr;
1059  #endif
1060  
1061  	kp = kprobe_running();
1062  
1063  	if (!kp || !(kp->flags & KPROBE_FLAG_ON_FUNC_ENTRY))
1064  		return 0;
1065  
1066  	return get_entry_ip((uintptr_t)kp->addr);
1067  }
1068  
1069  static const struct bpf_func_proto bpf_get_func_ip_proto_kprobe = {
1070  	.func		= bpf_get_func_ip_kprobe,
1071  	.gpl_only	= true,
1072  	.ret_type	= RET_INTEGER,
1073  	.arg1_type	= ARG_PTR_TO_CTX,
1074  };
1075  
BPF_CALL_1(bpf_get_func_ip_kprobe_multi,struct pt_regs *,regs)1076  BPF_CALL_1(bpf_get_func_ip_kprobe_multi, struct pt_regs *, regs)
1077  {
1078  	return bpf_kprobe_multi_entry_ip(current->bpf_ctx);
1079  }
1080  
1081  static const struct bpf_func_proto bpf_get_func_ip_proto_kprobe_multi = {
1082  	.func		= bpf_get_func_ip_kprobe_multi,
1083  	.gpl_only	= false,
1084  	.ret_type	= RET_INTEGER,
1085  	.arg1_type	= ARG_PTR_TO_CTX,
1086  };
1087  
BPF_CALL_1(bpf_get_attach_cookie_kprobe_multi,struct pt_regs *,regs)1088  BPF_CALL_1(bpf_get_attach_cookie_kprobe_multi, struct pt_regs *, regs)
1089  {
1090  	return bpf_kprobe_multi_cookie(current->bpf_ctx);
1091  }
1092  
1093  static const struct bpf_func_proto bpf_get_attach_cookie_proto_kmulti = {
1094  	.func		= bpf_get_attach_cookie_kprobe_multi,
1095  	.gpl_only	= false,
1096  	.ret_type	= RET_INTEGER,
1097  	.arg1_type	= ARG_PTR_TO_CTX,
1098  };
1099  
BPF_CALL_1(bpf_get_func_ip_uprobe_multi,struct pt_regs *,regs)1100  BPF_CALL_1(bpf_get_func_ip_uprobe_multi, struct pt_regs *, regs)
1101  {
1102  	return bpf_uprobe_multi_entry_ip(current->bpf_ctx);
1103  }
1104  
1105  static const struct bpf_func_proto bpf_get_func_ip_proto_uprobe_multi = {
1106  	.func		= bpf_get_func_ip_uprobe_multi,
1107  	.gpl_only	= false,
1108  	.ret_type	= RET_INTEGER,
1109  	.arg1_type	= ARG_PTR_TO_CTX,
1110  };
1111  
BPF_CALL_1(bpf_get_attach_cookie_uprobe_multi,struct pt_regs *,regs)1112  BPF_CALL_1(bpf_get_attach_cookie_uprobe_multi, struct pt_regs *, regs)
1113  {
1114  	return bpf_uprobe_multi_cookie(current->bpf_ctx);
1115  }
1116  
1117  static const struct bpf_func_proto bpf_get_attach_cookie_proto_umulti = {
1118  	.func		= bpf_get_attach_cookie_uprobe_multi,
1119  	.gpl_only	= false,
1120  	.ret_type	= RET_INTEGER,
1121  	.arg1_type	= ARG_PTR_TO_CTX,
1122  };
1123  
BPF_CALL_1(bpf_get_attach_cookie_trace,void *,ctx)1124  BPF_CALL_1(bpf_get_attach_cookie_trace, void *, ctx)
1125  {
1126  	struct bpf_trace_run_ctx *run_ctx;
1127  
1128  	run_ctx = container_of(current->bpf_ctx, struct bpf_trace_run_ctx, run_ctx);
1129  	return run_ctx->bpf_cookie;
1130  }
1131  
1132  static const struct bpf_func_proto bpf_get_attach_cookie_proto_trace = {
1133  	.func		= bpf_get_attach_cookie_trace,
1134  	.gpl_only	= false,
1135  	.ret_type	= RET_INTEGER,
1136  	.arg1_type	= ARG_PTR_TO_CTX,
1137  };
1138  
BPF_CALL_1(bpf_get_attach_cookie_pe,struct bpf_perf_event_data_kern *,ctx)1139  BPF_CALL_1(bpf_get_attach_cookie_pe, struct bpf_perf_event_data_kern *, ctx)
1140  {
1141  	return ctx->event->bpf_cookie;
1142  }
1143  
1144  static const struct bpf_func_proto bpf_get_attach_cookie_proto_pe = {
1145  	.func		= bpf_get_attach_cookie_pe,
1146  	.gpl_only	= false,
1147  	.ret_type	= RET_INTEGER,
1148  	.arg1_type	= ARG_PTR_TO_CTX,
1149  };
1150  
BPF_CALL_1(bpf_get_attach_cookie_tracing,void *,ctx)1151  BPF_CALL_1(bpf_get_attach_cookie_tracing, void *, ctx)
1152  {
1153  	struct bpf_trace_run_ctx *run_ctx;
1154  
1155  	run_ctx = container_of(current->bpf_ctx, struct bpf_trace_run_ctx, run_ctx);
1156  	return run_ctx->bpf_cookie;
1157  }
1158  
1159  static const struct bpf_func_proto bpf_get_attach_cookie_proto_tracing = {
1160  	.func		= bpf_get_attach_cookie_tracing,
1161  	.gpl_only	= false,
1162  	.ret_type	= RET_INTEGER,
1163  	.arg1_type	= ARG_PTR_TO_CTX,
1164  };
1165  
BPF_CALL_3(bpf_get_branch_snapshot,void *,buf,u32,size,u64,flags)1166  BPF_CALL_3(bpf_get_branch_snapshot, void *, buf, u32, size, u64, flags)
1167  {
1168  	static const u32 br_entry_size = sizeof(struct perf_branch_entry);
1169  	u32 entry_cnt = size / br_entry_size;
1170  
1171  	entry_cnt = static_call(perf_snapshot_branch_stack)(buf, entry_cnt);
1172  
1173  	if (unlikely(flags))
1174  		return -EINVAL;
1175  
1176  	if (!entry_cnt)
1177  		return -ENOENT;
1178  
1179  	return entry_cnt * br_entry_size;
1180  }
1181  
1182  static const struct bpf_func_proto bpf_get_branch_snapshot_proto = {
1183  	.func		= bpf_get_branch_snapshot,
1184  	.gpl_only	= true,
1185  	.ret_type	= RET_INTEGER,
1186  	.arg1_type	= ARG_PTR_TO_UNINIT_MEM,
1187  	.arg2_type	= ARG_CONST_SIZE_OR_ZERO,
1188  };
1189  
BPF_CALL_3(get_func_arg,void *,ctx,u32,n,u64 *,value)1190  BPF_CALL_3(get_func_arg, void *, ctx, u32, n, u64 *, value)
1191  {
1192  	/* This helper call is inlined by verifier. */
1193  	u64 nr_args = ((u64 *)ctx)[-1];
1194  
1195  	if ((u64) n >= nr_args)
1196  		return -EINVAL;
1197  	*value = ((u64 *)ctx)[n];
1198  	return 0;
1199  }
1200  
1201  static const struct bpf_func_proto bpf_get_func_arg_proto = {
1202  	.func		= get_func_arg,
1203  	.ret_type	= RET_INTEGER,
1204  	.arg1_type	= ARG_PTR_TO_CTX,
1205  	.arg2_type	= ARG_ANYTHING,
1206  	.arg3_type	= ARG_PTR_TO_FIXED_SIZE_MEM | MEM_UNINIT | MEM_WRITE | MEM_ALIGNED,
1207  	.arg3_size	= sizeof(u64),
1208  };
1209  
BPF_CALL_2(get_func_ret,void *,ctx,u64 *,value)1210  BPF_CALL_2(get_func_ret, void *, ctx, u64 *, value)
1211  {
1212  	/* This helper call is inlined by verifier. */
1213  	u64 nr_args = ((u64 *)ctx)[-1];
1214  
1215  	*value = ((u64 *)ctx)[nr_args];
1216  	return 0;
1217  }
1218  
1219  static const struct bpf_func_proto bpf_get_func_ret_proto = {
1220  	.func		= get_func_ret,
1221  	.ret_type	= RET_INTEGER,
1222  	.arg1_type	= ARG_PTR_TO_CTX,
1223  	.arg2_type	= ARG_PTR_TO_FIXED_SIZE_MEM | MEM_UNINIT | MEM_WRITE | MEM_ALIGNED,
1224  	.arg2_size	= sizeof(u64),
1225  };
1226  
BPF_CALL_1(get_func_arg_cnt,void *,ctx)1227  BPF_CALL_1(get_func_arg_cnt, void *, ctx)
1228  {
1229  	/* This helper call is inlined by verifier. */
1230  	return ((u64 *)ctx)[-1];
1231  }
1232  
1233  static const struct bpf_func_proto bpf_get_func_arg_cnt_proto = {
1234  	.func		= get_func_arg_cnt,
1235  	.ret_type	= RET_INTEGER,
1236  	.arg1_type	= ARG_PTR_TO_CTX,
1237  };
1238  
1239  #ifdef CONFIG_KEYS
1240  __bpf_kfunc_start_defs();
1241  
1242  /**
1243   * bpf_lookup_user_key - lookup a key by its serial
1244   * @serial: key handle serial number
1245   * @flags: lookup-specific flags
1246   *
1247   * Search a key with a given *serial* and the provided *flags*.
1248   * If found, increment the reference count of the key by one, and
1249   * return it in the bpf_key structure.
1250   *
1251   * The bpf_key structure must be passed to bpf_key_put() when done
1252   * with it, so that the key reference count is decremented and the
1253   * bpf_key structure is freed.
1254   *
1255   * Permission checks are deferred to the time the key is used by
1256   * one of the available key-specific kfuncs.
1257   *
1258   * Set *flags* with KEY_LOOKUP_CREATE, to attempt creating a requested
1259   * special keyring (e.g. session keyring), if it doesn't yet exist.
1260   * Set *flags* with KEY_LOOKUP_PARTIAL, to lookup a key without waiting
1261   * for the key construction, and to retrieve uninstantiated keys (keys
1262   * without data attached to them).
1263   *
1264   * Return: a bpf_key pointer with a valid key pointer if the key is found, a
1265   *         NULL pointer otherwise.
1266   */
bpf_lookup_user_key(u32 serial,u64 flags)1267  __bpf_kfunc struct bpf_key *bpf_lookup_user_key(u32 serial, u64 flags)
1268  {
1269  	key_ref_t key_ref;
1270  	struct bpf_key *bkey;
1271  
1272  	if (flags & ~KEY_LOOKUP_ALL)
1273  		return NULL;
1274  
1275  	/*
1276  	 * Permission check is deferred until the key is used, as the
1277  	 * intent of the caller is unknown here.
1278  	 */
1279  	key_ref = lookup_user_key(serial, flags, KEY_DEFER_PERM_CHECK);
1280  	if (IS_ERR(key_ref))
1281  		return NULL;
1282  
1283  	bkey = kmalloc(sizeof(*bkey), GFP_KERNEL);
1284  	if (!bkey) {
1285  		key_put(key_ref_to_ptr(key_ref));
1286  		return NULL;
1287  	}
1288  
1289  	bkey->key = key_ref_to_ptr(key_ref);
1290  	bkey->has_ref = true;
1291  
1292  	return bkey;
1293  }
1294  
1295  /**
1296   * bpf_lookup_system_key - lookup a key by a system-defined ID
1297   * @id: key ID
1298   *
1299   * Obtain a bpf_key structure with a key pointer set to the passed key ID.
1300   * The key pointer is marked as invalid, to prevent bpf_key_put() from
1301   * attempting to decrement the key reference count on that pointer. The key
1302   * pointer set in such way is currently understood only by
1303   * verify_pkcs7_signature().
1304   *
1305   * Set *id* to one of the values defined in include/linux/verification.h:
1306   * 0 for the primary keyring (immutable keyring of system keys);
1307   * VERIFY_USE_SECONDARY_KEYRING for both the primary and secondary keyring
1308   * (where keys can be added only if they are vouched for by existing keys
1309   * in those keyrings); VERIFY_USE_PLATFORM_KEYRING for the platform
1310   * keyring (primarily used by the integrity subsystem to verify a kexec'ed
1311   * kerned image and, possibly, the initramfs signature).
1312   *
1313   * Return: a bpf_key pointer with an invalid key pointer set from the
1314   *         pre-determined ID on success, a NULL pointer otherwise
1315   */
bpf_lookup_system_key(u64 id)1316  __bpf_kfunc struct bpf_key *bpf_lookup_system_key(u64 id)
1317  {
1318  	struct bpf_key *bkey;
1319  
1320  	if (system_keyring_id_check(id) < 0)
1321  		return NULL;
1322  
1323  	bkey = kmalloc(sizeof(*bkey), GFP_ATOMIC);
1324  	if (!bkey)
1325  		return NULL;
1326  
1327  	bkey->key = (struct key *)(unsigned long)id;
1328  	bkey->has_ref = false;
1329  
1330  	return bkey;
1331  }
1332  
1333  /**
1334   * bpf_key_put - decrement key reference count if key is valid and free bpf_key
1335   * @bkey: bpf_key structure
1336   *
1337   * Decrement the reference count of the key inside *bkey*, if the pointer
1338   * is valid, and free *bkey*.
1339   */
bpf_key_put(struct bpf_key * bkey)1340  __bpf_kfunc void bpf_key_put(struct bpf_key *bkey)
1341  {
1342  	if (bkey->has_ref)
1343  		key_put(bkey->key);
1344  
1345  	kfree(bkey);
1346  }
1347  
1348  #ifdef CONFIG_SYSTEM_DATA_VERIFICATION
1349  /**
1350   * bpf_verify_pkcs7_signature - verify a PKCS#7 signature
1351   * @data_p: data to verify
1352   * @sig_p: signature of the data
1353   * @trusted_keyring: keyring with keys trusted for signature verification
1354   *
1355   * Verify the PKCS#7 signature *sig_ptr* against the supplied *data_ptr*
1356   * with keys in a keyring referenced by *trusted_keyring*.
1357   *
1358   * Return: 0 on success, a negative value on error.
1359   */
bpf_verify_pkcs7_signature(struct bpf_dynptr * data_p,struct bpf_dynptr * sig_p,struct bpf_key * trusted_keyring)1360  __bpf_kfunc int bpf_verify_pkcs7_signature(struct bpf_dynptr *data_p,
1361  			       struct bpf_dynptr *sig_p,
1362  			       struct bpf_key *trusted_keyring)
1363  {
1364  	struct bpf_dynptr_kern *data_ptr = (struct bpf_dynptr_kern *)data_p;
1365  	struct bpf_dynptr_kern *sig_ptr = (struct bpf_dynptr_kern *)sig_p;
1366  	const void *data, *sig;
1367  	u32 data_len, sig_len;
1368  	int ret;
1369  
1370  	if (trusted_keyring->has_ref) {
1371  		/*
1372  		 * Do the permission check deferred in bpf_lookup_user_key().
1373  		 * See bpf_lookup_user_key() for more details.
1374  		 *
1375  		 * A call to key_task_permission() here would be redundant, as
1376  		 * it is already done by keyring_search() called by
1377  		 * find_asymmetric_key().
1378  		 */
1379  		ret = key_validate(trusted_keyring->key);
1380  		if (ret < 0)
1381  			return ret;
1382  	}
1383  
1384  	data_len = __bpf_dynptr_size(data_ptr);
1385  	data = __bpf_dynptr_data(data_ptr, data_len);
1386  	sig_len = __bpf_dynptr_size(sig_ptr);
1387  	sig = __bpf_dynptr_data(sig_ptr, sig_len);
1388  
1389  	return verify_pkcs7_signature(data, data_len, sig, sig_len,
1390  				      trusted_keyring->key,
1391  				      VERIFYING_UNSPECIFIED_SIGNATURE, NULL,
1392  				      NULL);
1393  }
1394  #endif /* CONFIG_SYSTEM_DATA_VERIFICATION */
1395  
1396  __bpf_kfunc_end_defs();
1397  
1398  BTF_KFUNCS_START(key_sig_kfunc_set)
1399  BTF_ID_FLAGS(func, bpf_lookup_user_key, KF_ACQUIRE | KF_RET_NULL | KF_SLEEPABLE)
1400  BTF_ID_FLAGS(func, bpf_lookup_system_key, KF_ACQUIRE | KF_RET_NULL)
1401  BTF_ID_FLAGS(func, bpf_key_put, KF_RELEASE)
1402  #ifdef CONFIG_SYSTEM_DATA_VERIFICATION
1403  BTF_ID_FLAGS(func, bpf_verify_pkcs7_signature, KF_SLEEPABLE)
1404  #endif
1405  BTF_KFUNCS_END(key_sig_kfunc_set)
1406  
1407  static const struct btf_kfunc_id_set bpf_key_sig_kfunc_set = {
1408  	.owner = THIS_MODULE,
1409  	.set = &key_sig_kfunc_set,
1410  };
1411  
bpf_key_sig_kfuncs_init(void)1412  static int __init bpf_key_sig_kfuncs_init(void)
1413  {
1414  	return register_btf_kfunc_id_set(BPF_PROG_TYPE_TRACING,
1415  					 &bpf_key_sig_kfunc_set);
1416  }
1417  
1418  late_initcall(bpf_key_sig_kfuncs_init);
1419  #endif /* CONFIG_KEYS */
1420  
1421  static const struct bpf_func_proto *
bpf_tracing_func_proto(enum bpf_func_id func_id,const struct bpf_prog * prog)1422  bpf_tracing_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
1423  {
1424  	const struct bpf_func_proto *func_proto;
1425  
1426  	switch (func_id) {
1427  	case BPF_FUNC_map_lookup_elem:
1428  		return &bpf_map_lookup_elem_proto;
1429  	case BPF_FUNC_map_update_elem:
1430  		return &bpf_map_update_elem_proto;
1431  	case BPF_FUNC_map_delete_elem:
1432  		return &bpf_map_delete_elem_proto;
1433  	case BPF_FUNC_map_push_elem:
1434  		return &bpf_map_push_elem_proto;
1435  	case BPF_FUNC_map_pop_elem:
1436  		return &bpf_map_pop_elem_proto;
1437  	case BPF_FUNC_map_peek_elem:
1438  		return &bpf_map_peek_elem_proto;
1439  	case BPF_FUNC_map_lookup_percpu_elem:
1440  		return &bpf_map_lookup_percpu_elem_proto;
1441  	case BPF_FUNC_ktime_get_ns:
1442  		return &bpf_ktime_get_ns_proto;
1443  	case BPF_FUNC_ktime_get_boot_ns:
1444  		return &bpf_ktime_get_boot_ns_proto;
1445  	case BPF_FUNC_tail_call:
1446  		return &bpf_tail_call_proto;
1447  	case BPF_FUNC_get_current_task:
1448  		return &bpf_get_current_task_proto;
1449  	case BPF_FUNC_get_current_task_btf:
1450  		return &bpf_get_current_task_btf_proto;
1451  	case BPF_FUNC_task_pt_regs:
1452  		return &bpf_task_pt_regs_proto;
1453  	case BPF_FUNC_get_current_uid_gid:
1454  		return &bpf_get_current_uid_gid_proto;
1455  	case BPF_FUNC_get_current_comm:
1456  		return &bpf_get_current_comm_proto;
1457  	case BPF_FUNC_trace_printk:
1458  		return bpf_get_trace_printk_proto();
1459  	case BPF_FUNC_get_smp_processor_id:
1460  		return &bpf_get_smp_processor_id_proto;
1461  	case BPF_FUNC_get_numa_node_id:
1462  		return &bpf_get_numa_node_id_proto;
1463  	case BPF_FUNC_perf_event_read:
1464  		return &bpf_perf_event_read_proto;
1465  	case BPF_FUNC_get_prandom_u32:
1466  		return &bpf_get_prandom_u32_proto;
1467  	case BPF_FUNC_probe_read_user:
1468  		return &bpf_probe_read_user_proto;
1469  	case BPF_FUNC_probe_read_kernel:
1470  		return security_locked_down(LOCKDOWN_BPF_READ_KERNEL) < 0 ?
1471  		       NULL : &bpf_probe_read_kernel_proto;
1472  	case BPF_FUNC_probe_read_user_str:
1473  		return &bpf_probe_read_user_str_proto;
1474  	case BPF_FUNC_probe_read_kernel_str:
1475  		return security_locked_down(LOCKDOWN_BPF_READ_KERNEL) < 0 ?
1476  		       NULL : &bpf_probe_read_kernel_str_proto;
1477  #ifdef CONFIG_ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE
1478  	case BPF_FUNC_probe_read:
1479  		return security_locked_down(LOCKDOWN_BPF_READ_KERNEL) < 0 ?
1480  		       NULL : &bpf_probe_read_compat_proto;
1481  	case BPF_FUNC_probe_read_str:
1482  		return security_locked_down(LOCKDOWN_BPF_READ_KERNEL) < 0 ?
1483  		       NULL : &bpf_probe_read_compat_str_proto;
1484  #endif
1485  #ifdef CONFIG_CGROUPS
1486  	case BPF_FUNC_cgrp_storage_get:
1487  		return &bpf_cgrp_storage_get_proto;
1488  	case BPF_FUNC_cgrp_storage_delete:
1489  		return &bpf_cgrp_storage_delete_proto;
1490  	case BPF_FUNC_current_task_under_cgroup:
1491  		return &bpf_current_task_under_cgroup_proto;
1492  #endif
1493  	case BPF_FUNC_send_signal:
1494  		return &bpf_send_signal_proto;
1495  	case BPF_FUNC_send_signal_thread:
1496  		return &bpf_send_signal_thread_proto;
1497  	case BPF_FUNC_perf_event_read_value:
1498  		return &bpf_perf_event_read_value_proto;
1499  	case BPF_FUNC_ringbuf_output:
1500  		return &bpf_ringbuf_output_proto;
1501  	case BPF_FUNC_ringbuf_reserve:
1502  		return &bpf_ringbuf_reserve_proto;
1503  	case BPF_FUNC_ringbuf_submit:
1504  		return &bpf_ringbuf_submit_proto;
1505  	case BPF_FUNC_ringbuf_discard:
1506  		return &bpf_ringbuf_discard_proto;
1507  	case BPF_FUNC_ringbuf_query:
1508  		return &bpf_ringbuf_query_proto;
1509  	case BPF_FUNC_jiffies64:
1510  		return &bpf_jiffies64_proto;
1511  	case BPF_FUNC_get_task_stack:
1512  		return prog->sleepable ? &bpf_get_task_stack_sleepable_proto
1513  				       : &bpf_get_task_stack_proto;
1514  	case BPF_FUNC_copy_from_user:
1515  		return &bpf_copy_from_user_proto;
1516  	case BPF_FUNC_copy_from_user_task:
1517  		return &bpf_copy_from_user_task_proto;
1518  	case BPF_FUNC_snprintf_btf:
1519  		return &bpf_snprintf_btf_proto;
1520  	case BPF_FUNC_per_cpu_ptr:
1521  		return &bpf_per_cpu_ptr_proto;
1522  	case BPF_FUNC_this_cpu_ptr:
1523  		return &bpf_this_cpu_ptr_proto;
1524  	case BPF_FUNC_task_storage_get:
1525  		if (bpf_prog_check_recur(prog))
1526  			return &bpf_task_storage_get_recur_proto;
1527  		return &bpf_task_storage_get_proto;
1528  	case BPF_FUNC_task_storage_delete:
1529  		if (bpf_prog_check_recur(prog))
1530  			return &bpf_task_storage_delete_recur_proto;
1531  		return &bpf_task_storage_delete_proto;
1532  	case BPF_FUNC_for_each_map_elem:
1533  		return &bpf_for_each_map_elem_proto;
1534  	case BPF_FUNC_snprintf:
1535  		return &bpf_snprintf_proto;
1536  	case BPF_FUNC_get_func_ip:
1537  		return &bpf_get_func_ip_proto_tracing;
1538  	case BPF_FUNC_get_branch_snapshot:
1539  		return &bpf_get_branch_snapshot_proto;
1540  	case BPF_FUNC_find_vma:
1541  		return &bpf_find_vma_proto;
1542  	case BPF_FUNC_trace_vprintk:
1543  		return bpf_get_trace_vprintk_proto();
1544  	default:
1545  		break;
1546  	}
1547  
1548  	func_proto = bpf_base_func_proto(func_id, prog);
1549  	if (func_proto)
1550  		return func_proto;
1551  
1552  	if (!bpf_token_capable(prog->aux->token, CAP_SYS_ADMIN))
1553  		return NULL;
1554  
1555  	switch (func_id) {
1556  	case BPF_FUNC_probe_write_user:
1557  		return security_locked_down(LOCKDOWN_BPF_WRITE_USER) < 0 ?
1558  		       NULL : &bpf_probe_write_user_proto;
1559  	default:
1560  		return NULL;
1561  	}
1562  }
1563  
is_kprobe_multi(const struct bpf_prog * prog)1564  static bool is_kprobe_multi(const struct bpf_prog *prog)
1565  {
1566  	return prog->expected_attach_type == BPF_TRACE_KPROBE_MULTI ||
1567  	       prog->expected_attach_type == BPF_TRACE_KPROBE_SESSION;
1568  }
1569  
is_kprobe_session(const struct bpf_prog * prog)1570  static inline bool is_kprobe_session(const struct bpf_prog *prog)
1571  {
1572  	return prog->expected_attach_type == BPF_TRACE_KPROBE_SESSION;
1573  }
1574  
is_uprobe_multi(const struct bpf_prog * prog)1575  static inline bool is_uprobe_multi(const struct bpf_prog *prog)
1576  {
1577  	return prog->expected_attach_type == BPF_TRACE_UPROBE_MULTI ||
1578  	       prog->expected_attach_type == BPF_TRACE_UPROBE_SESSION;
1579  }
1580  
is_uprobe_session(const struct bpf_prog * prog)1581  static inline bool is_uprobe_session(const struct bpf_prog *prog)
1582  {
1583  	return prog->expected_attach_type == BPF_TRACE_UPROBE_SESSION;
1584  }
1585  
1586  static const struct bpf_func_proto *
kprobe_prog_func_proto(enum bpf_func_id func_id,const struct bpf_prog * prog)1587  kprobe_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
1588  {
1589  	switch (func_id) {
1590  	case BPF_FUNC_perf_event_output:
1591  		return &bpf_perf_event_output_proto;
1592  	case BPF_FUNC_get_stackid:
1593  		return &bpf_get_stackid_proto;
1594  	case BPF_FUNC_get_stack:
1595  		return prog->sleepable ? &bpf_get_stack_sleepable_proto : &bpf_get_stack_proto;
1596  #ifdef CONFIG_BPF_KPROBE_OVERRIDE
1597  	case BPF_FUNC_override_return:
1598  		return &bpf_override_return_proto;
1599  #endif
1600  	case BPF_FUNC_get_func_ip:
1601  		if (is_kprobe_multi(prog))
1602  			return &bpf_get_func_ip_proto_kprobe_multi;
1603  		if (is_uprobe_multi(prog))
1604  			return &bpf_get_func_ip_proto_uprobe_multi;
1605  		return &bpf_get_func_ip_proto_kprobe;
1606  	case BPF_FUNC_get_attach_cookie:
1607  		if (is_kprobe_multi(prog))
1608  			return &bpf_get_attach_cookie_proto_kmulti;
1609  		if (is_uprobe_multi(prog))
1610  			return &bpf_get_attach_cookie_proto_umulti;
1611  		return &bpf_get_attach_cookie_proto_trace;
1612  	default:
1613  		return bpf_tracing_func_proto(func_id, prog);
1614  	}
1615  }
1616  
1617  /* bpf+kprobe programs can access fields of 'struct pt_regs' */
kprobe_prog_is_valid_access(int off,int size,enum bpf_access_type type,const struct bpf_prog * prog,struct bpf_insn_access_aux * info)1618  static bool kprobe_prog_is_valid_access(int off, int size, enum bpf_access_type type,
1619  					const struct bpf_prog *prog,
1620  					struct bpf_insn_access_aux *info)
1621  {
1622  	if (off < 0 || off >= sizeof(struct pt_regs))
1623  		return false;
1624  	if (type != BPF_READ)
1625  		return false;
1626  	if (off % size != 0)
1627  		return false;
1628  	/*
1629  	 * Assertion for 32 bit to make sure last 8 byte access
1630  	 * (BPF_DW) to the last 4 byte member is disallowed.
1631  	 */
1632  	if (off + size > sizeof(struct pt_regs))
1633  		return false;
1634  
1635  	return true;
1636  }
1637  
1638  const struct bpf_verifier_ops kprobe_verifier_ops = {
1639  	.get_func_proto  = kprobe_prog_func_proto,
1640  	.is_valid_access = kprobe_prog_is_valid_access,
1641  };
1642  
1643  const struct bpf_prog_ops kprobe_prog_ops = {
1644  };
1645  
BPF_CALL_5(bpf_perf_event_output_tp,void *,tp_buff,struct bpf_map *,map,u64,flags,void *,data,u64,size)1646  BPF_CALL_5(bpf_perf_event_output_tp, void *, tp_buff, struct bpf_map *, map,
1647  	   u64, flags, void *, data, u64, size)
1648  {
1649  	struct pt_regs *regs = *(struct pt_regs **)tp_buff;
1650  
1651  	/*
1652  	 * r1 points to perf tracepoint buffer where first 8 bytes are hidden
1653  	 * from bpf program and contain a pointer to 'struct pt_regs'. Fetch it
1654  	 * from there and call the same bpf_perf_event_output() helper inline.
1655  	 */
1656  	return ____bpf_perf_event_output(regs, map, flags, data, size);
1657  }
1658  
1659  static const struct bpf_func_proto bpf_perf_event_output_proto_tp = {
1660  	.func		= bpf_perf_event_output_tp,
1661  	.gpl_only	= true,
1662  	.ret_type	= RET_INTEGER,
1663  	.arg1_type	= ARG_PTR_TO_CTX,
1664  	.arg2_type	= ARG_CONST_MAP_PTR,
1665  	.arg3_type	= ARG_ANYTHING,
1666  	.arg4_type	= ARG_PTR_TO_MEM | MEM_RDONLY,
1667  	.arg5_type	= ARG_CONST_SIZE_OR_ZERO,
1668  };
1669  
BPF_CALL_3(bpf_get_stackid_tp,void *,tp_buff,struct bpf_map *,map,u64,flags)1670  BPF_CALL_3(bpf_get_stackid_tp, void *, tp_buff, struct bpf_map *, map,
1671  	   u64, flags)
1672  {
1673  	struct pt_regs *regs = *(struct pt_regs **)tp_buff;
1674  
1675  	/*
1676  	 * Same comment as in bpf_perf_event_output_tp(), only that this time
1677  	 * the other helper's function body cannot be inlined due to being
1678  	 * external, thus we need to call raw helper function.
1679  	 */
1680  	return bpf_get_stackid((unsigned long) regs, (unsigned long) map,
1681  			       flags, 0, 0);
1682  }
1683  
1684  static const struct bpf_func_proto bpf_get_stackid_proto_tp = {
1685  	.func		= bpf_get_stackid_tp,
1686  	.gpl_only	= true,
1687  	.ret_type	= RET_INTEGER,
1688  	.arg1_type	= ARG_PTR_TO_CTX,
1689  	.arg2_type	= ARG_CONST_MAP_PTR,
1690  	.arg3_type	= ARG_ANYTHING,
1691  };
1692  
BPF_CALL_4(bpf_get_stack_tp,void *,tp_buff,void *,buf,u32,size,u64,flags)1693  BPF_CALL_4(bpf_get_stack_tp, void *, tp_buff, void *, buf, u32, size,
1694  	   u64, flags)
1695  {
1696  	struct pt_regs *regs = *(struct pt_regs **)tp_buff;
1697  
1698  	return bpf_get_stack((unsigned long) regs, (unsigned long) buf,
1699  			     (unsigned long) size, flags, 0);
1700  }
1701  
1702  static const struct bpf_func_proto bpf_get_stack_proto_tp = {
1703  	.func		= bpf_get_stack_tp,
1704  	.gpl_only	= true,
1705  	.ret_type	= RET_INTEGER,
1706  	.arg1_type	= ARG_PTR_TO_CTX,
1707  	.arg2_type	= ARG_PTR_TO_UNINIT_MEM,
1708  	.arg3_type	= ARG_CONST_SIZE_OR_ZERO,
1709  	.arg4_type	= ARG_ANYTHING,
1710  };
1711  
1712  static const struct bpf_func_proto *
tp_prog_func_proto(enum bpf_func_id func_id,const struct bpf_prog * prog)1713  tp_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
1714  {
1715  	switch (func_id) {
1716  	case BPF_FUNC_perf_event_output:
1717  		return &bpf_perf_event_output_proto_tp;
1718  	case BPF_FUNC_get_stackid:
1719  		return &bpf_get_stackid_proto_tp;
1720  	case BPF_FUNC_get_stack:
1721  		return &bpf_get_stack_proto_tp;
1722  	case BPF_FUNC_get_attach_cookie:
1723  		return &bpf_get_attach_cookie_proto_trace;
1724  	default:
1725  		return bpf_tracing_func_proto(func_id, prog);
1726  	}
1727  }
1728  
tp_prog_is_valid_access(int off,int size,enum bpf_access_type type,const struct bpf_prog * prog,struct bpf_insn_access_aux * info)1729  static bool tp_prog_is_valid_access(int off, int size, enum bpf_access_type type,
1730  				    const struct bpf_prog *prog,
1731  				    struct bpf_insn_access_aux *info)
1732  {
1733  	if (off < sizeof(void *) || off >= PERF_MAX_TRACE_SIZE)
1734  		return false;
1735  	if (type != BPF_READ)
1736  		return false;
1737  	if (off % size != 0)
1738  		return false;
1739  
1740  	BUILD_BUG_ON(PERF_MAX_TRACE_SIZE % sizeof(__u64));
1741  	return true;
1742  }
1743  
1744  const struct bpf_verifier_ops tracepoint_verifier_ops = {
1745  	.get_func_proto  = tp_prog_func_proto,
1746  	.is_valid_access = tp_prog_is_valid_access,
1747  };
1748  
1749  const struct bpf_prog_ops tracepoint_prog_ops = {
1750  };
1751  
BPF_CALL_3(bpf_perf_prog_read_value,struct bpf_perf_event_data_kern *,ctx,struct bpf_perf_event_value *,buf,u32,size)1752  BPF_CALL_3(bpf_perf_prog_read_value, struct bpf_perf_event_data_kern *, ctx,
1753  	   struct bpf_perf_event_value *, buf, u32, size)
1754  {
1755  	int err = -EINVAL;
1756  
1757  	if (unlikely(size != sizeof(struct bpf_perf_event_value)))
1758  		goto clear;
1759  	err = perf_event_read_local(ctx->event, &buf->counter, &buf->enabled,
1760  				    &buf->running);
1761  	if (unlikely(err))
1762  		goto clear;
1763  	return 0;
1764  clear:
1765  	memset(buf, 0, size);
1766  	return err;
1767  }
1768  
1769  static const struct bpf_func_proto bpf_perf_prog_read_value_proto = {
1770           .func           = bpf_perf_prog_read_value,
1771           .gpl_only       = true,
1772           .ret_type       = RET_INTEGER,
1773           .arg1_type      = ARG_PTR_TO_CTX,
1774           .arg2_type      = ARG_PTR_TO_UNINIT_MEM,
1775           .arg3_type      = ARG_CONST_SIZE,
1776  };
1777  
BPF_CALL_4(bpf_read_branch_records,struct bpf_perf_event_data_kern *,ctx,void *,buf,u32,size,u64,flags)1778  BPF_CALL_4(bpf_read_branch_records, struct bpf_perf_event_data_kern *, ctx,
1779  	   void *, buf, u32, size, u64, flags)
1780  {
1781  	static const u32 br_entry_size = sizeof(struct perf_branch_entry);
1782  	struct perf_branch_stack *br_stack = ctx->data->br_stack;
1783  	u32 to_copy;
1784  
1785  	if (unlikely(flags & ~BPF_F_GET_BRANCH_RECORDS_SIZE))
1786  		return -EINVAL;
1787  
1788  	if (unlikely(!(ctx->data->sample_flags & PERF_SAMPLE_BRANCH_STACK)))
1789  		return -ENOENT;
1790  
1791  	if (unlikely(!br_stack))
1792  		return -ENOENT;
1793  
1794  	if (flags & BPF_F_GET_BRANCH_RECORDS_SIZE)
1795  		return br_stack->nr * br_entry_size;
1796  
1797  	if (!buf || (size % br_entry_size != 0))
1798  		return -EINVAL;
1799  
1800  	to_copy = min_t(u32, br_stack->nr * br_entry_size, size);
1801  	memcpy(buf, br_stack->entries, to_copy);
1802  
1803  	return to_copy;
1804  }
1805  
1806  static const struct bpf_func_proto bpf_read_branch_records_proto = {
1807  	.func           = bpf_read_branch_records,
1808  	.gpl_only       = true,
1809  	.ret_type       = RET_INTEGER,
1810  	.arg1_type      = ARG_PTR_TO_CTX,
1811  	.arg2_type      = ARG_PTR_TO_MEM_OR_NULL,
1812  	.arg3_type      = ARG_CONST_SIZE_OR_ZERO,
1813  	.arg4_type      = ARG_ANYTHING,
1814  };
1815  
1816  static const struct bpf_func_proto *
pe_prog_func_proto(enum bpf_func_id func_id,const struct bpf_prog * prog)1817  pe_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
1818  {
1819  	switch (func_id) {
1820  	case BPF_FUNC_perf_event_output:
1821  		return &bpf_perf_event_output_proto_tp;
1822  	case BPF_FUNC_get_stackid:
1823  		return &bpf_get_stackid_proto_pe;
1824  	case BPF_FUNC_get_stack:
1825  		return &bpf_get_stack_proto_pe;
1826  	case BPF_FUNC_perf_prog_read_value:
1827  		return &bpf_perf_prog_read_value_proto;
1828  	case BPF_FUNC_read_branch_records:
1829  		return &bpf_read_branch_records_proto;
1830  	case BPF_FUNC_get_attach_cookie:
1831  		return &bpf_get_attach_cookie_proto_pe;
1832  	default:
1833  		return bpf_tracing_func_proto(func_id, prog);
1834  	}
1835  }
1836  
1837  /*
1838   * bpf_raw_tp_regs are separate from bpf_pt_regs used from skb/xdp
1839   * to avoid potential recursive reuse issue when/if tracepoints are added
1840   * inside bpf_*_event_output, bpf_get_stackid and/or bpf_get_stack.
1841   *
1842   * Since raw tracepoints run despite bpf_prog_active, support concurrent usage
1843   * in normal, irq, and nmi context.
1844   */
1845  struct bpf_raw_tp_regs {
1846  	struct pt_regs regs[3];
1847  };
1848  static DEFINE_PER_CPU(struct bpf_raw_tp_regs, bpf_raw_tp_regs);
1849  static DEFINE_PER_CPU(int, bpf_raw_tp_nest_level);
get_bpf_raw_tp_regs(void)1850  static struct pt_regs *get_bpf_raw_tp_regs(void)
1851  {
1852  	struct bpf_raw_tp_regs *tp_regs = this_cpu_ptr(&bpf_raw_tp_regs);
1853  	int nest_level = this_cpu_inc_return(bpf_raw_tp_nest_level);
1854  
1855  	if (WARN_ON_ONCE(nest_level > ARRAY_SIZE(tp_regs->regs))) {
1856  		this_cpu_dec(bpf_raw_tp_nest_level);
1857  		return ERR_PTR(-EBUSY);
1858  	}
1859  
1860  	return &tp_regs->regs[nest_level - 1];
1861  }
1862  
put_bpf_raw_tp_regs(void)1863  static void put_bpf_raw_tp_regs(void)
1864  {
1865  	this_cpu_dec(bpf_raw_tp_nest_level);
1866  }
1867  
BPF_CALL_5(bpf_perf_event_output_raw_tp,struct bpf_raw_tracepoint_args *,args,struct bpf_map *,map,u64,flags,void *,data,u64,size)1868  BPF_CALL_5(bpf_perf_event_output_raw_tp, struct bpf_raw_tracepoint_args *, args,
1869  	   struct bpf_map *, map, u64, flags, void *, data, u64, size)
1870  {
1871  	struct pt_regs *regs = get_bpf_raw_tp_regs();
1872  	int ret;
1873  
1874  	if (IS_ERR(regs))
1875  		return PTR_ERR(regs);
1876  
1877  	perf_fetch_caller_regs(regs);
1878  	ret = ____bpf_perf_event_output(regs, map, flags, data, size);
1879  
1880  	put_bpf_raw_tp_regs();
1881  	return ret;
1882  }
1883  
1884  static const struct bpf_func_proto bpf_perf_event_output_proto_raw_tp = {
1885  	.func		= bpf_perf_event_output_raw_tp,
1886  	.gpl_only	= true,
1887  	.ret_type	= RET_INTEGER,
1888  	.arg1_type	= ARG_PTR_TO_CTX,
1889  	.arg2_type	= ARG_CONST_MAP_PTR,
1890  	.arg3_type	= ARG_ANYTHING,
1891  	.arg4_type	= ARG_PTR_TO_MEM | MEM_RDONLY,
1892  	.arg5_type	= ARG_CONST_SIZE_OR_ZERO,
1893  };
1894  
1895  extern const struct bpf_func_proto bpf_skb_output_proto;
1896  extern const struct bpf_func_proto bpf_xdp_output_proto;
1897  extern const struct bpf_func_proto bpf_xdp_get_buff_len_trace_proto;
1898  
BPF_CALL_3(bpf_get_stackid_raw_tp,struct bpf_raw_tracepoint_args *,args,struct bpf_map *,map,u64,flags)1899  BPF_CALL_3(bpf_get_stackid_raw_tp, struct bpf_raw_tracepoint_args *, args,
1900  	   struct bpf_map *, map, u64, flags)
1901  {
1902  	struct pt_regs *regs = get_bpf_raw_tp_regs();
1903  	int ret;
1904  
1905  	if (IS_ERR(regs))
1906  		return PTR_ERR(regs);
1907  
1908  	perf_fetch_caller_regs(regs);
1909  	/* similar to bpf_perf_event_output_tp, but pt_regs fetched differently */
1910  	ret = bpf_get_stackid((unsigned long) regs, (unsigned long) map,
1911  			      flags, 0, 0);
1912  	put_bpf_raw_tp_regs();
1913  	return ret;
1914  }
1915  
1916  static const struct bpf_func_proto bpf_get_stackid_proto_raw_tp = {
1917  	.func		= bpf_get_stackid_raw_tp,
1918  	.gpl_only	= true,
1919  	.ret_type	= RET_INTEGER,
1920  	.arg1_type	= ARG_PTR_TO_CTX,
1921  	.arg2_type	= ARG_CONST_MAP_PTR,
1922  	.arg3_type	= ARG_ANYTHING,
1923  };
1924  
BPF_CALL_4(bpf_get_stack_raw_tp,struct bpf_raw_tracepoint_args *,args,void *,buf,u32,size,u64,flags)1925  BPF_CALL_4(bpf_get_stack_raw_tp, struct bpf_raw_tracepoint_args *, args,
1926  	   void *, buf, u32, size, u64, flags)
1927  {
1928  	struct pt_regs *regs = get_bpf_raw_tp_regs();
1929  	int ret;
1930  
1931  	if (IS_ERR(regs))
1932  		return PTR_ERR(regs);
1933  
1934  	perf_fetch_caller_regs(regs);
1935  	ret = bpf_get_stack((unsigned long) regs, (unsigned long) buf,
1936  			    (unsigned long) size, flags, 0);
1937  	put_bpf_raw_tp_regs();
1938  	return ret;
1939  }
1940  
1941  static const struct bpf_func_proto bpf_get_stack_proto_raw_tp = {
1942  	.func		= bpf_get_stack_raw_tp,
1943  	.gpl_only	= true,
1944  	.ret_type	= RET_INTEGER,
1945  	.arg1_type	= ARG_PTR_TO_CTX,
1946  	.arg2_type	= ARG_PTR_TO_MEM | MEM_RDONLY,
1947  	.arg3_type	= ARG_CONST_SIZE_OR_ZERO,
1948  	.arg4_type	= ARG_ANYTHING,
1949  };
1950  
1951  static const struct bpf_func_proto *
raw_tp_prog_func_proto(enum bpf_func_id func_id,const struct bpf_prog * prog)1952  raw_tp_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
1953  {
1954  	switch (func_id) {
1955  	case BPF_FUNC_perf_event_output:
1956  		return &bpf_perf_event_output_proto_raw_tp;
1957  	case BPF_FUNC_get_stackid:
1958  		return &bpf_get_stackid_proto_raw_tp;
1959  	case BPF_FUNC_get_stack:
1960  		return &bpf_get_stack_proto_raw_tp;
1961  	case BPF_FUNC_get_attach_cookie:
1962  		return &bpf_get_attach_cookie_proto_tracing;
1963  	default:
1964  		return bpf_tracing_func_proto(func_id, prog);
1965  	}
1966  }
1967  
1968  const struct bpf_func_proto *
tracing_prog_func_proto(enum bpf_func_id func_id,const struct bpf_prog * prog)1969  tracing_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
1970  {
1971  	const struct bpf_func_proto *fn;
1972  
1973  	switch (func_id) {
1974  #ifdef CONFIG_NET
1975  	case BPF_FUNC_skb_output:
1976  		return &bpf_skb_output_proto;
1977  	case BPF_FUNC_xdp_output:
1978  		return &bpf_xdp_output_proto;
1979  	case BPF_FUNC_skc_to_tcp6_sock:
1980  		return &bpf_skc_to_tcp6_sock_proto;
1981  	case BPF_FUNC_skc_to_tcp_sock:
1982  		return &bpf_skc_to_tcp_sock_proto;
1983  	case BPF_FUNC_skc_to_tcp_timewait_sock:
1984  		return &bpf_skc_to_tcp_timewait_sock_proto;
1985  	case BPF_FUNC_skc_to_tcp_request_sock:
1986  		return &bpf_skc_to_tcp_request_sock_proto;
1987  	case BPF_FUNC_skc_to_udp6_sock:
1988  		return &bpf_skc_to_udp6_sock_proto;
1989  	case BPF_FUNC_skc_to_unix_sock:
1990  		return &bpf_skc_to_unix_sock_proto;
1991  	case BPF_FUNC_skc_to_mptcp_sock:
1992  		return &bpf_skc_to_mptcp_sock_proto;
1993  	case BPF_FUNC_sk_storage_get:
1994  		return &bpf_sk_storage_get_tracing_proto;
1995  	case BPF_FUNC_sk_storage_delete:
1996  		return &bpf_sk_storage_delete_tracing_proto;
1997  	case BPF_FUNC_sock_from_file:
1998  		return &bpf_sock_from_file_proto;
1999  	case BPF_FUNC_get_socket_cookie:
2000  		return &bpf_get_socket_ptr_cookie_proto;
2001  	case BPF_FUNC_xdp_get_buff_len:
2002  		return &bpf_xdp_get_buff_len_trace_proto;
2003  #endif
2004  	case BPF_FUNC_seq_printf:
2005  		return prog->expected_attach_type == BPF_TRACE_ITER ?
2006  		       &bpf_seq_printf_proto :
2007  		       NULL;
2008  	case BPF_FUNC_seq_write:
2009  		return prog->expected_attach_type == BPF_TRACE_ITER ?
2010  		       &bpf_seq_write_proto :
2011  		       NULL;
2012  	case BPF_FUNC_seq_printf_btf:
2013  		return prog->expected_attach_type == BPF_TRACE_ITER ?
2014  		       &bpf_seq_printf_btf_proto :
2015  		       NULL;
2016  	case BPF_FUNC_d_path:
2017  		return &bpf_d_path_proto;
2018  	case BPF_FUNC_get_func_arg:
2019  		return bpf_prog_has_trampoline(prog) ? &bpf_get_func_arg_proto : NULL;
2020  	case BPF_FUNC_get_func_ret:
2021  		return bpf_prog_has_trampoline(prog) ? &bpf_get_func_ret_proto : NULL;
2022  	case BPF_FUNC_get_func_arg_cnt:
2023  		return bpf_prog_has_trampoline(prog) ? &bpf_get_func_arg_cnt_proto : NULL;
2024  	case BPF_FUNC_get_attach_cookie:
2025  		if (prog->type == BPF_PROG_TYPE_TRACING &&
2026  		    prog->expected_attach_type == BPF_TRACE_RAW_TP)
2027  			return &bpf_get_attach_cookie_proto_tracing;
2028  		return bpf_prog_has_trampoline(prog) ? &bpf_get_attach_cookie_proto_tracing : NULL;
2029  	default:
2030  		fn = raw_tp_prog_func_proto(func_id, prog);
2031  		if (!fn && prog->expected_attach_type == BPF_TRACE_ITER)
2032  			fn = bpf_iter_get_func_proto(func_id, prog);
2033  		return fn;
2034  	}
2035  }
2036  
raw_tp_prog_is_valid_access(int off,int size,enum bpf_access_type type,const struct bpf_prog * prog,struct bpf_insn_access_aux * info)2037  static bool raw_tp_prog_is_valid_access(int off, int size,
2038  					enum bpf_access_type type,
2039  					const struct bpf_prog *prog,
2040  					struct bpf_insn_access_aux *info)
2041  {
2042  	return bpf_tracing_ctx_access(off, size, type);
2043  }
2044  
tracing_prog_is_valid_access(int off,int size,enum bpf_access_type type,const struct bpf_prog * prog,struct bpf_insn_access_aux * info)2045  static bool tracing_prog_is_valid_access(int off, int size,
2046  					 enum bpf_access_type type,
2047  					 const struct bpf_prog *prog,
2048  					 struct bpf_insn_access_aux *info)
2049  {
2050  	return bpf_tracing_btf_ctx_access(off, size, type, prog, info);
2051  }
2052  
bpf_prog_test_run_tracing(struct bpf_prog * prog,const union bpf_attr * kattr,union bpf_attr __user * uattr)2053  int __weak bpf_prog_test_run_tracing(struct bpf_prog *prog,
2054  				     const union bpf_attr *kattr,
2055  				     union bpf_attr __user *uattr)
2056  {
2057  	return -ENOTSUPP;
2058  }
2059  
2060  const struct bpf_verifier_ops raw_tracepoint_verifier_ops = {
2061  	.get_func_proto  = raw_tp_prog_func_proto,
2062  	.is_valid_access = raw_tp_prog_is_valid_access,
2063  };
2064  
2065  const struct bpf_prog_ops raw_tracepoint_prog_ops = {
2066  #ifdef CONFIG_NET
2067  	.test_run = bpf_prog_test_run_raw_tp,
2068  #endif
2069  };
2070  
2071  const struct bpf_verifier_ops tracing_verifier_ops = {
2072  	.get_func_proto  = tracing_prog_func_proto,
2073  	.is_valid_access = tracing_prog_is_valid_access,
2074  };
2075  
2076  const struct bpf_prog_ops tracing_prog_ops = {
2077  	.test_run = bpf_prog_test_run_tracing,
2078  };
2079  
raw_tp_writable_prog_is_valid_access(int off,int size,enum bpf_access_type type,const struct bpf_prog * prog,struct bpf_insn_access_aux * info)2080  static bool raw_tp_writable_prog_is_valid_access(int off, int size,
2081  						 enum bpf_access_type type,
2082  						 const struct bpf_prog *prog,
2083  						 struct bpf_insn_access_aux *info)
2084  {
2085  	if (off == 0) {
2086  		if (size != sizeof(u64) || type != BPF_READ)
2087  			return false;
2088  		info->reg_type = PTR_TO_TP_BUFFER;
2089  	}
2090  	return raw_tp_prog_is_valid_access(off, size, type, prog, info);
2091  }
2092  
2093  const struct bpf_verifier_ops raw_tracepoint_writable_verifier_ops = {
2094  	.get_func_proto  = raw_tp_prog_func_proto,
2095  	.is_valid_access = raw_tp_writable_prog_is_valid_access,
2096  };
2097  
2098  const struct bpf_prog_ops raw_tracepoint_writable_prog_ops = {
2099  };
2100  
pe_prog_is_valid_access(int off,int size,enum bpf_access_type type,const struct bpf_prog * prog,struct bpf_insn_access_aux * info)2101  static bool pe_prog_is_valid_access(int off, int size, enum bpf_access_type type,
2102  				    const struct bpf_prog *prog,
2103  				    struct bpf_insn_access_aux *info)
2104  {
2105  	const int size_u64 = sizeof(u64);
2106  
2107  	if (off < 0 || off >= sizeof(struct bpf_perf_event_data))
2108  		return false;
2109  	if (type != BPF_READ)
2110  		return false;
2111  	if (off % size != 0) {
2112  		if (sizeof(unsigned long) != 4)
2113  			return false;
2114  		if (size != 8)
2115  			return false;
2116  		if (off % size != 4)
2117  			return false;
2118  	}
2119  
2120  	switch (off) {
2121  	case bpf_ctx_range(struct bpf_perf_event_data, sample_period):
2122  		bpf_ctx_record_field_size(info, size_u64);
2123  		if (!bpf_ctx_narrow_access_ok(off, size, size_u64))
2124  			return false;
2125  		break;
2126  	case bpf_ctx_range(struct bpf_perf_event_data, addr):
2127  		bpf_ctx_record_field_size(info, size_u64);
2128  		if (!bpf_ctx_narrow_access_ok(off, size, size_u64))
2129  			return false;
2130  		break;
2131  	default:
2132  		if (size != sizeof(long))
2133  			return false;
2134  	}
2135  
2136  	return true;
2137  }
2138  
pe_prog_convert_ctx_access(enum bpf_access_type type,const struct bpf_insn * si,struct bpf_insn * insn_buf,struct bpf_prog * prog,u32 * target_size)2139  static u32 pe_prog_convert_ctx_access(enum bpf_access_type type,
2140  				      const struct bpf_insn *si,
2141  				      struct bpf_insn *insn_buf,
2142  				      struct bpf_prog *prog, u32 *target_size)
2143  {
2144  	struct bpf_insn *insn = insn_buf;
2145  
2146  	switch (si->off) {
2147  	case offsetof(struct bpf_perf_event_data, sample_period):
2148  		*insn++ = BPF_LDX_MEM(BPF_FIELD_SIZEOF(struct bpf_perf_event_data_kern,
2149  						       data), si->dst_reg, si->src_reg,
2150  				      offsetof(struct bpf_perf_event_data_kern, data));
2151  		*insn++ = BPF_LDX_MEM(BPF_DW, si->dst_reg, si->dst_reg,
2152  				      bpf_target_off(struct perf_sample_data, period, 8,
2153  						     target_size));
2154  		break;
2155  	case offsetof(struct bpf_perf_event_data, addr):
2156  		*insn++ = BPF_LDX_MEM(BPF_FIELD_SIZEOF(struct bpf_perf_event_data_kern,
2157  						       data), si->dst_reg, si->src_reg,
2158  				      offsetof(struct bpf_perf_event_data_kern, data));
2159  		*insn++ = BPF_LDX_MEM(BPF_DW, si->dst_reg, si->dst_reg,
2160  				      bpf_target_off(struct perf_sample_data, addr, 8,
2161  						     target_size));
2162  		break;
2163  	default:
2164  		*insn++ = BPF_LDX_MEM(BPF_FIELD_SIZEOF(struct bpf_perf_event_data_kern,
2165  						       regs), si->dst_reg, si->src_reg,
2166  				      offsetof(struct bpf_perf_event_data_kern, regs));
2167  		*insn++ = BPF_LDX_MEM(BPF_SIZEOF(long), si->dst_reg, si->dst_reg,
2168  				      si->off);
2169  		break;
2170  	}
2171  
2172  	return insn - insn_buf;
2173  }
2174  
2175  const struct bpf_verifier_ops perf_event_verifier_ops = {
2176  	.get_func_proto		= pe_prog_func_proto,
2177  	.is_valid_access	= pe_prog_is_valid_access,
2178  	.convert_ctx_access	= pe_prog_convert_ctx_access,
2179  };
2180  
2181  const struct bpf_prog_ops perf_event_prog_ops = {
2182  };
2183  
2184  static DEFINE_MUTEX(bpf_event_mutex);
2185  
2186  #define BPF_TRACE_MAX_PROGS 64
2187  
perf_event_attach_bpf_prog(struct perf_event * event,struct bpf_prog * prog,u64 bpf_cookie)2188  int perf_event_attach_bpf_prog(struct perf_event *event,
2189  			       struct bpf_prog *prog,
2190  			       u64 bpf_cookie)
2191  {
2192  	struct bpf_prog_array *old_array;
2193  	struct bpf_prog_array *new_array;
2194  	int ret = -EEXIST;
2195  
2196  	/*
2197  	 * Kprobe override only works if they are on the function entry,
2198  	 * and only if they are on the opt-in list.
2199  	 */
2200  	if (prog->kprobe_override &&
2201  	    (!trace_kprobe_on_func_entry(event->tp_event) ||
2202  	     !trace_kprobe_error_injectable(event->tp_event)))
2203  		return -EINVAL;
2204  
2205  	mutex_lock(&bpf_event_mutex);
2206  
2207  	if (event->prog)
2208  		goto unlock;
2209  
2210  	old_array = bpf_event_rcu_dereference(event->tp_event->prog_array);
2211  	if (old_array &&
2212  	    bpf_prog_array_length(old_array) >= BPF_TRACE_MAX_PROGS) {
2213  		ret = -E2BIG;
2214  		goto unlock;
2215  	}
2216  
2217  	ret = bpf_prog_array_copy(old_array, NULL, prog, bpf_cookie, &new_array);
2218  	if (ret < 0)
2219  		goto unlock;
2220  
2221  	/* set the new array to event->tp_event and set event->prog */
2222  	event->prog = prog;
2223  	event->bpf_cookie = bpf_cookie;
2224  	rcu_assign_pointer(event->tp_event->prog_array, new_array);
2225  	bpf_prog_array_free_sleepable(old_array);
2226  
2227  unlock:
2228  	mutex_unlock(&bpf_event_mutex);
2229  	return ret;
2230  }
2231  
perf_event_detach_bpf_prog(struct perf_event * event)2232  void perf_event_detach_bpf_prog(struct perf_event *event)
2233  {
2234  	struct bpf_prog_array *old_array;
2235  	struct bpf_prog_array *new_array;
2236  	struct bpf_prog *prog = NULL;
2237  	int ret;
2238  
2239  	mutex_lock(&bpf_event_mutex);
2240  
2241  	if (!event->prog)
2242  		goto unlock;
2243  
2244  	old_array = bpf_event_rcu_dereference(event->tp_event->prog_array);
2245  	if (!old_array)
2246  		goto put;
2247  
2248  	ret = bpf_prog_array_copy(old_array, event->prog, NULL, 0, &new_array);
2249  	if (ret < 0) {
2250  		bpf_prog_array_delete_safe(old_array, event->prog);
2251  	} else {
2252  		rcu_assign_pointer(event->tp_event->prog_array, new_array);
2253  		bpf_prog_array_free_sleepable(old_array);
2254  	}
2255  
2256  put:
2257  	prog = event->prog;
2258  	event->prog = NULL;
2259  
2260  unlock:
2261  	mutex_unlock(&bpf_event_mutex);
2262  
2263  	if (prog) {
2264  		/*
2265  		 * It could be that the bpf_prog is not sleepable (and will be freed
2266  		 * via normal RCU), but is called from a point that supports sleepable
2267  		 * programs and uses tasks-trace-RCU.
2268  		 */
2269  		synchronize_rcu_tasks_trace();
2270  
2271  		bpf_prog_put(prog);
2272  	}
2273  }
2274  
perf_event_query_prog_array(struct perf_event * event,void __user * info)2275  int perf_event_query_prog_array(struct perf_event *event, void __user *info)
2276  {
2277  	struct perf_event_query_bpf __user *uquery = info;
2278  	struct perf_event_query_bpf query = {};
2279  	struct bpf_prog_array *progs;
2280  	u32 *ids, prog_cnt, ids_len;
2281  	int ret;
2282  
2283  	if (!perfmon_capable())
2284  		return -EPERM;
2285  	if (event->attr.type != PERF_TYPE_TRACEPOINT)
2286  		return -EINVAL;
2287  	if (copy_from_user(&query, uquery, sizeof(query)))
2288  		return -EFAULT;
2289  
2290  	ids_len = query.ids_len;
2291  	if (ids_len > BPF_TRACE_MAX_PROGS)
2292  		return -E2BIG;
2293  	ids = kcalloc(ids_len, sizeof(u32), GFP_USER | __GFP_NOWARN);
2294  	if (!ids)
2295  		return -ENOMEM;
2296  	/*
2297  	 * The above kcalloc returns ZERO_SIZE_PTR when ids_len = 0, which
2298  	 * is required when user only wants to check for uquery->prog_cnt.
2299  	 * There is no need to check for it since the case is handled
2300  	 * gracefully in bpf_prog_array_copy_info.
2301  	 */
2302  
2303  	mutex_lock(&bpf_event_mutex);
2304  	progs = bpf_event_rcu_dereference(event->tp_event->prog_array);
2305  	ret = bpf_prog_array_copy_info(progs, ids, ids_len, &prog_cnt);
2306  	mutex_unlock(&bpf_event_mutex);
2307  
2308  	if (copy_to_user(&uquery->prog_cnt, &prog_cnt, sizeof(prog_cnt)) ||
2309  	    copy_to_user(uquery->ids, ids, ids_len * sizeof(u32)))
2310  		ret = -EFAULT;
2311  
2312  	kfree(ids);
2313  	return ret;
2314  }
2315  
2316  extern struct bpf_raw_event_map __start__bpf_raw_tp[];
2317  extern struct bpf_raw_event_map __stop__bpf_raw_tp[];
2318  
bpf_get_raw_tracepoint(const char * name)2319  struct bpf_raw_event_map *bpf_get_raw_tracepoint(const char *name)
2320  {
2321  	struct bpf_raw_event_map *btp = __start__bpf_raw_tp;
2322  
2323  	for (; btp < __stop__bpf_raw_tp; btp++) {
2324  		if (!strcmp(btp->tp->name, name))
2325  			return btp;
2326  	}
2327  
2328  	return bpf_get_raw_tracepoint_module(name);
2329  }
2330  
bpf_put_raw_tracepoint(struct bpf_raw_event_map * btp)2331  void bpf_put_raw_tracepoint(struct bpf_raw_event_map *btp)
2332  {
2333  	struct module *mod;
2334  
2335  	preempt_disable();
2336  	mod = __module_address((unsigned long)btp);
2337  	module_put(mod);
2338  	preempt_enable();
2339  }
2340  
2341  static __always_inline
__bpf_trace_run(struct bpf_raw_tp_link * link,u64 * args)2342  void __bpf_trace_run(struct bpf_raw_tp_link *link, u64 *args)
2343  {
2344  	struct bpf_prog *prog = link->link.prog;
2345  	struct bpf_run_ctx *old_run_ctx;
2346  	struct bpf_trace_run_ctx run_ctx;
2347  
2348  	cant_sleep();
2349  	if (unlikely(this_cpu_inc_return(*(prog->active)) != 1)) {
2350  		bpf_prog_inc_misses_counter(prog);
2351  		goto out;
2352  	}
2353  
2354  	run_ctx.bpf_cookie = link->cookie;
2355  	old_run_ctx = bpf_set_run_ctx(&run_ctx.run_ctx);
2356  
2357  	rcu_read_lock();
2358  	(void) bpf_prog_run(prog, args);
2359  	rcu_read_unlock();
2360  
2361  	bpf_reset_run_ctx(old_run_ctx);
2362  out:
2363  	this_cpu_dec(*(prog->active));
2364  }
2365  
2366  #define UNPACK(...)			__VA_ARGS__
2367  #define REPEAT_1(FN, DL, X, ...)	FN(X)
2368  #define REPEAT_2(FN, DL, X, ...)	FN(X) UNPACK DL REPEAT_1(FN, DL, __VA_ARGS__)
2369  #define REPEAT_3(FN, DL, X, ...)	FN(X) UNPACK DL REPEAT_2(FN, DL, __VA_ARGS__)
2370  #define REPEAT_4(FN, DL, X, ...)	FN(X) UNPACK DL REPEAT_3(FN, DL, __VA_ARGS__)
2371  #define REPEAT_5(FN, DL, X, ...)	FN(X) UNPACK DL REPEAT_4(FN, DL, __VA_ARGS__)
2372  #define REPEAT_6(FN, DL, X, ...)	FN(X) UNPACK DL REPEAT_5(FN, DL, __VA_ARGS__)
2373  #define REPEAT_7(FN, DL, X, ...)	FN(X) UNPACK DL REPEAT_6(FN, DL, __VA_ARGS__)
2374  #define REPEAT_8(FN, DL, X, ...)	FN(X) UNPACK DL REPEAT_7(FN, DL, __VA_ARGS__)
2375  #define REPEAT_9(FN, DL, X, ...)	FN(X) UNPACK DL REPEAT_8(FN, DL, __VA_ARGS__)
2376  #define REPEAT_10(FN, DL, X, ...)	FN(X) UNPACK DL REPEAT_9(FN, DL, __VA_ARGS__)
2377  #define REPEAT_11(FN, DL, X, ...)	FN(X) UNPACK DL REPEAT_10(FN, DL, __VA_ARGS__)
2378  #define REPEAT_12(FN, DL, X, ...)	FN(X) UNPACK DL REPEAT_11(FN, DL, __VA_ARGS__)
2379  #define REPEAT(X, FN, DL, ...)		REPEAT_##X(FN, DL, __VA_ARGS__)
2380  
2381  #define SARG(X)		u64 arg##X
2382  #define COPY(X)		args[X] = arg##X
2383  
2384  #define __DL_COM	(,)
2385  #define __DL_SEM	(;)
2386  
2387  #define __SEQ_0_11	0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11
2388  
2389  #define BPF_TRACE_DEFN_x(x)						\
2390  	void bpf_trace_run##x(struct bpf_raw_tp_link *link,		\
2391  			      REPEAT(x, SARG, __DL_COM, __SEQ_0_11))	\
2392  	{								\
2393  		u64 args[x];						\
2394  		REPEAT(x, COPY, __DL_SEM, __SEQ_0_11);			\
2395  		__bpf_trace_run(link, args);				\
2396  	}								\
2397  	EXPORT_SYMBOL_GPL(bpf_trace_run##x)
2398  BPF_TRACE_DEFN_x(1);
2399  BPF_TRACE_DEFN_x(2);
2400  BPF_TRACE_DEFN_x(3);
2401  BPF_TRACE_DEFN_x(4);
2402  BPF_TRACE_DEFN_x(5);
2403  BPF_TRACE_DEFN_x(6);
2404  BPF_TRACE_DEFN_x(7);
2405  BPF_TRACE_DEFN_x(8);
2406  BPF_TRACE_DEFN_x(9);
2407  BPF_TRACE_DEFN_x(10);
2408  BPF_TRACE_DEFN_x(11);
2409  BPF_TRACE_DEFN_x(12);
2410  
bpf_probe_register(struct bpf_raw_event_map * btp,struct bpf_raw_tp_link * link)2411  int bpf_probe_register(struct bpf_raw_event_map *btp, struct bpf_raw_tp_link *link)
2412  {
2413  	struct tracepoint *tp = btp->tp;
2414  	struct bpf_prog *prog = link->link.prog;
2415  
2416  	/*
2417  	 * check that program doesn't access arguments beyond what's
2418  	 * available in this tracepoint
2419  	 */
2420  	if (prog->aux->max_ctx_offset > btp->num_args * sizeof(u64))
2421  		return -EINVAL;
2422  
2423  	if (prog->aux->max_tp_access > btp->writable_size)
2424  		return -EINVAL;
2425  
2426  	return tracepoint_probe_register_may_exist(tp, (void *)btp->bpf_func, link);
2427  }
2428  
bpf_probe_unregister(struct bpf_raw_event_map * btp,struct bpf_raw_tp_link * link)2429  int bpf_probe_unregister(struct bpf_raw_event_map *btp, struct bpf_raw_tp_link *link)
2430  {
2431  	return tracepoint_probe_unregister(btp->tp, (void *)btp->bpf_func, link);
2432  }
2433  
bpf_get_perf_event_info(const struct perf_event * event,u32 * prog_id,u32 * fd_type,const char ** buf,u64 * probe_offset,u64 * probe_addr,unsigned long * missed)2434  int bpf_get_perf_event_info(const struct perf_event *event, u32 *prog_id,
2435  			    u32 *fd_type, const char **buf,
2436  			    u64 *probe_offset, u64 *probe_addr,
2437  			    unsigned long *missed)
2438  {
2439  	bool is_tracepoint, is_syscall_tp;
2440  	struct bpf_prog *prog;
2441  	int flags, err = 0;
2442  
2443  	prog = event->prog;
2444  	if (!prog)
2445  		return -ENOENT;
2446  
2447  	/* not supporting BPF_PROG_TYPE_PERF_EVENT yet */
2448  	if (prog->type == BPF_PROG_TYPE_PERF_EVENT)
2449  		return -EOPNOTSUPP;
2450  
2451  	*prog_id = prog->aux->id;
2452  	flags = event->tp_event->flags;
2453  	is_tracepoint = flags & TRACE_EVENT_FL_TRACEPOINT;
2454  	is_syscall_tp = is_syscall_trace_event(event->tp_event);
2455  
2456  	if (is_tracepoint || is_syscall_tp) {
2457  		*buf = is_tracepoint ? event->tp_event->tp->name
2458  				     : event->tp_event->name;
2459  		/* We allow NULL pointer for tracepoint */
2460  		if (fd_type)
2461  			*fd_type = BPF_FD_TYPE_TRACEPOINT;
2462  		if (probe_offset)
2463  			*probe_offset = 0x0;
2464  		if (probe_addr)
2465  			*probe_addr = 0x0;
2466  	} else {
2467  		/* kprobe/uprobe */
2468  		err = -EOPNOTSUPP;
2469  #ifdef CONFIG_KPROBE_EVENTS
2470  		if (flags & TRACE_EVENT_FL_KPROBE)
2471  			err = bpf_get_kprobe_info(event, fd_type, buf,
2472  						  probe_offset, probe_addr, missed,
2473  						  event->attr.type == PERF_TYPE_TRACEPOINT);
2474  #endif
2475  #ifdef CONFIG_UPROBE_EVENTS
2476  		if (flags & TRACE_EVENT_FL_UPROBE)
2477  			err = bpf_get_uprobe_info(event, fd_type, buf,
2478  						  probe_offset, probe_addr,
2479  						  event->attr.type == PERF_TYPE_TRACEPOINT);
2480  #endif
2481  	}
2482  
2483  	return err;
2484  }
2485  
send_signal_irq_work_init(void)2486  static int __init send_signal_irq_work_init(void)
2487  {
2488  	int cpu;
2489  	struct send_signal_irq_work *work;
2490  
2491  	for_each_possible_cpu(cpu) {
2492  		work = per_cpu_ptr(&send_signal_work, cpu);
2493  		init_irq_work(&work->irq_work, do_bpf_send_signal);
2494  	}
2495  	return 0;
2496  }
2497  
2498  subsys_initcall(send_signal_irq_work_init);
2499  
2500  #ifdef CONFIG_MODULES
bpf_event_notify(struct notifier_block * nb,unsigned long op,void * module)2501  static int bpf_event_notify(struct notifier_block *nb, unsigned long op,
2502  			    void *module)
2503  {
2504  	struct bpf_trace_module *btm, *tmp;
2505  	struct module *mod = module;
2506  	int ret = 0;
2507  
2508  	if (mod->num_bpf_raw_events == 0 ||
2509  	    (op != MODULE_STATE_COMING && op != MODULE_STATE_GOING))
2510  		goto out;
2511  
2512  	mutex_lock(&bpf_module_mutex);
2513  
2514  	switch (op) {
2515  	case MODULE_STATE_COMING:
2516  		btm = kzalloc(sizeof(*btm), GFP_KERNEL);
2517  		if (btm) {
2518  			btm->module = module;
2519  			list_add(&btm->list, &bpf_trace_modules);
2520  		} else {
2521  			ret = -ENOMEM;
2522  		}
2523  		break;
2524  	case MODULE_STATE_GOING:
2525  		list_for_each_entry_safe(btm, tmp, &bpf_trace_modules, list) {
2526  			if (btm->module == module) {
2527  				list_del(&btm->list);
2528  				kfree(btm);
2529  				break;
2530  			}
2531  		}
2532  		break;
2533  	}
2534  
2535  	mutex_unlock(&bpf_module_mutex);
2536  
2537  out:
2538  	return notifier_from_errno(ret);
2539  }
2540  
2541  static struct notifier_block bpf_module_nb = {
2542  	.notifier_call = bpf_event_notify,
2543  };
2544  
bpf_event_init(void)2545  static int __init bpf_event_init(void)
2546  {
2547  	register_module_notifier(&bpf_module_nb);
2548  	return 0;
2549  }
2550  
2551  fs_initcall(bpf_event_init);
2552  #endif /* CONFIG_MODULES */
2553  
2554  struct bpf_session_run_ctx {
2555  	struct bpf_run_ctx run_ctx;
2556  	bool is_return;
2557  	void *data;
2558  };
2559  
2560  #ifdef CONFIG_FPROBE
2561  struct bpf_kprobe_multi_link {
2562  	struct bpf_link link;
2563  	struct fprobe fp;
2564  	unsigned long *addrs;
2565  	u64 *cookies;
2566  	u32 cnt;
2567  	u32 mods_cnt;
2568  	struct module **mods;
2569  	u32 flags;
2570  };
2571  
2572  struct bpf_kprobe_multi_run_ctx {
2573  	struct bpf_session_run_ctx session_ctx;
2574  	struct bpf_kprobe_multi_link *link;
2575  	unsigned long entry_ip;
2576  };
2577  
2578  struct user_syms {
2579  	const char **syms;
2580  	char *buf;
2581  };
2582  
2583  #ifndef CONFIG_HAVE_FTRACE_REGS_HAVING_PT_REGS
2584  static DEFINE_PER_CPU(struct pt_regs, bpf_kprobe_multi_pt_regs);
2585  #define bpf_kprobe_multi_pt_regs_ptr()	this_cpu_ptr(&bpf_kprobe_multi_pt_regs)
2586  #else
2587  #define bpf_kprobe_multi_pt_regs_ptr()	(NULL)
2588  #endif
2589  
ftrace_get_entry_ip(unsigned long fentry_ip)2590  static unsigned long ftrace_get_entry_ip(unsigned long fentry_ip)
2591  {
2592  	unsigned long ip = ftrace_get_symaddr(fentry_ip);
2593  
2594  	return ip ? : fentry_ip;
2595  }
2596  
copy_user_syms(struct user_syms * us,unsigned long __user * usyms,u32 cnt)2597  static int copy_user_syms(struct user_syms *us, unsigned long __user *usyms, u32 cnt)
2598  {
2599  	unsigned long __user usymbol;
2600  	const char **syms = NULL;
2601  	char *buf = NULL, *p;
2602  	int err = -ENOMEM;
2603  	unsigned int i;
2604  
2605  	syms = kvmalloc_array(cnt, sizeof(*syms), GFP_KERNEL);
2606  	if (!syms)
2607  		goto error;
2608  
2609  	buf = kvmalloc_array(cnt, KSYM_NAME_LEN, GFP_KERNEL);
2610  	if (!buf)
2611  		goto error;
2612  
2613  	for (p = buf, i = 0; i < cnt; i++) {
2614  		if (__get_user(usymbol, usyms + i)) {
2615  			err = -EFAULT;
2616  			goto error;
2617  		}
2618  		err = strncpy_from_user(p, (const char __user *) usymbol, KSYM_NAME_LEN);
2619  		if (err == KSYM_NAME_LEN)
2620  			err = -E2BIG;
2621  		if (err < 0)
2622  			goto error;
2623  		syms[i] = p;
2624  		p += err + 1;
2625  	}
2626  
2627  	us->syms = syms;
2628  	us->buf = buf;
2629  	return 0;
2630  
2631  error:
2632  	if (err) {
2633  		kvfree(syms);
2634  		kvfree(buf);
2635  	}
2636  	return err;
2637  }
2638  
kprobe_multi_put_modules(struct module ** mods,u32 cnt)2639  static void kprobe_multi_put_modules(struct module **mods, u32 cnt)
2640  {
2641  	u32 i;
2642  
2643  	for (i = 0; i < cnt; i++)
2644  		module_put(mods[i]);
2645  }
2646  
free_user_syms(struct user_syms * us)2647  static void free_user_syms(struct user_syms *us)
2648  {
2649  	kvfree(us->syms);
2650  	kvfree(us->buf);
2651  }
2652  
bpf_kprobe_multi_link_release(struct bpf_link * link)2653  static void bpf_kprobe_multi_link_release(struct bpf_link *link)
2654  {
2655  	struct bpf_kprobe_multi_link *kmulti_link;
2656  
2657  	kmulti_link = container_of(link, struct bpf_kprobe_multi_link, link);
2658  	unregister_fprobe(&kmulti_link->fp);
2659  	kprobe_multi_put_modules(kmulti_link->mods, kmulti_link->mods_cnt);
2660  }
2661  
bpf_kprobe_multi_link_dealloc(struct bpf_link * link)2662  static void bpf_kprobe_multi_link_dealloc(struct bpf_link *link)
2663  {
2664  	struct bpf_kprobe_multi_link *kmulti_link;
2665  
2666  	kmulti_link = container_of(link, struct bpf_kprobe_multi_link, link);
2667  	kvfree(kmulti_link->addrs);
2668  	kvfree(kmulti_link->cookies);
2669  	kfree(kmulti_link->mods);
2670  	kfree(kmulti_link);
2671  }
2672  
bpf_kprobe_multi_link_fill_link_info(const struct bpf_link * link,struct bpf_link_info * info)2673  static int bpf_kprobe_multi_link_fill_link_info(const struct bpf_link *link,
2674  						struct bpf_link_info *info)
2675  {
2676  	u64 __user *ucookies = u64_to_user_ptr(info->kprobe_multi.cookies);
2677  	u64 __user *uaddrs = u64_to_user_ptr(info->kprobe_multi.addrs);
2678  	struct bpf_kprobe_multi_link *kmulti_link;
2679  	u32 ucount = info->kprobe_multi.count;
2680  	int err = 0, i;
2681  
2682  	if (!uaddrs ^ !ucount)
2683  		return -EINVAL;
2684  	if (ucookies && !ucount)
2685  		return -EINVAL;
2686  
2687  	kmulti_link = container_of(link, struct bpf_kprobe_multi_link, link);
2688  	info->kprobe_multi.count = kmulti_link->cnt;
2689  	info->kprobe_multi.flags = kmulti_link->flags;
2690  	info->kprobe_multi.missed = kmulti_link->fp.nmissed;
2691  
2692  	if (!uaddrs)
2693  		return 0;
2694  	if (ucount < kmulti_link->cnt)
2695  		err = -ENOSPC;
2696  	else
2697  		ucount = kmulti_link->cnt;
2698  
2699  	if (ucookies) {
2700  		if (kmulti_link->cookies) {
2701  			if (copy_to_user(ucookies, kmulti_link->cookies, ucount * sizeof(u64)))
2702  				return -EFAULT;
2703  		} else {
2704  			for (i = 0; i < ucount; i++) {
2705  				if (put_user(0, ucookies + i))
2706  					return -EFAULT;
2707  			}
2708  		}
2709  	}
2710  
2711  	if (kallsyms_show_value(current_cred())) {
2712  		if (copy_to_user(uaddrs, kmulti_link->addrs, ucount * sizeof(u64)))
2713  			return -EFAULT;
2714  	} else {
2715  		for (i = 0; i < ucount; i++) {
2716  			if (put_user(0, uaddrs + i))
2717  				return -EFAULT;
2718  		}
2719  	}
2720  	return err;
2721  }
2722  
2723  static const struct bpf_link_ops bpf_kprobe_multi_link_lops = {
2724  	.release = bpf_kprobe_multi_link_release,
2725  	.dealloc_deferred = bpf_kprobe_multi_link_dealloc,
2726  	.fill_link_info = bpf_kprobe_multi_link_fill_link_info,
2727  };
2728  
bpf_kprobe_multi_cookie_swap(void * a,void * b,int size,const void * priv)2729  static void bpf_kprobe_multi_cookie_swap(void *a, void *b, int size, const void *priv)
2730  {
2731  	const struct bpf_kprobe_multi_link *link = priv;
2732  	unsigned long *addr_a = a, *addr_b = b;
2733  	u64 *cookie_a, *cookie_b;
2734  
2735  	cookie_a = link->cookies + (addr_a - link->addrs);
2736  	cookie_b = link->cookies + (addr_b - link->addrs);
2737  
2738  	/* swap addr_a/addr_b and cookie_a/cookie_b values */
2739  	swap(*addr_a, *addr_b);
2740  	swap(*cookie_a, *cookie_b);
2741  }
2742  
bpf_kprobe_multi_addrs_cmp(const void * a,const void * b)2743  static int bpf_kprobe_multi_addrs_cmp(const void *a, const void *b)
2744  {
2745  	const unsigned long *addr_a = a, *addr_b = b;
2746  
2747  	if (*addr_a == *addr_b)
2748  		return 0;
2749  	return *addr_a < *addr_b ? -1 : 1;
2750  }
2751  
bpf_kprobe_multi_cookie_cmp(const void * a,const void * b,const void * priv)2752  static int bpf_kprobe_multi_cookie_cmp(const void *a, const void *b, const void *priv)
2753  {
2754  	return bpf_kprobe_multi_addrs_cmp(a, b);
2755  }
2756  
bpf_kprobe_multi_cookie(struct bpf_run_ctx * ctx)2757  static u64 bpf_kprobe_multi_cookie(struct bpf_run_ctx *ctx)
2758  {
2759  	struct bpf_kprobe_multi_run_ctx *run_ctx;
2760  	struct bpf_kprobe_multi_link *link;
2761  	u64 *cookie, entry_ip;
2762  	unsigned long *addr;
2763  
2764  	if (WARN_ON_ONCE(!ctx))
2765  		return 0;
2766  	run_ctx = container_of(current->bpf_ctx, struct bpf_kprobe_multi_run_ctx,
2767  			       session_ctx.run_ctx);
2768  	link = run_ctx->link;
2769  	if (!link->cookies)
2770  		return 0;
2771  	entry_ip = run_ctx->entry_ip;
2772  	addr = bsearch(&entry_ip, link->addrs, link->cnt, sizeof(entry_ip),
2773  		       bpf_kprobe_multi_addrs_cmp);
2774  	if (!addr)
2775  		return 0;
2776  	cookie = link->cookies + (addr - link->addrs);
2777  	return *cookie;
2778  }
2779  
bpf_kprobe_multi_entry_ip(struct bpf_run_ctx * ctx)2780  static u64 bpf_kprobe_multi_entry_ip(struct bpf_run_ctx *ctx)
2781  {
2782  	struct bpf_kprobe_multi_run_ctx *run_ctx;
2783  
2784  	run_ctx = container_of(current->bpf_ctx, struct bpf_kprobe_multi_run_ctx,
2785  			       session_ctx.run_ctx);
2786  	return run_ctx->entry_ip;
2787  }
2788  
2789  static int
kprobe_multi_link_prog_run(struct bpf_kprobe_multi_link * link,unsigned long entry_ip,struct ftrace_regs * fregs,bool is_return,void * data)2790  kprobe_multi_link_prog_run(struct bpf_kprobe_multi_link *link,
2791  			   unsigned long entry_ip, struct ftrace_regs *fregs,
2792  			   bool is_return, void *data)
2793  {
2794  	struct bpf_kprobe_multi_run_ctx run_ctx = {
2795  		.session_ctx = {
2796  			.is_return = is_return,
2797  			.data = data,
2798  		},
2799  		.link = link,
2800  		.entry_ip = entry_ip,
2801  	};
2802  	struct bpf_run_ctx *old_run_ctx;
2803  	struct pt_regs *regs;
2804  	int err;
2805  
2806  	if (unlikely(__this_cpu_inc_return(bpf_prog_active) != 1)) {
2807  		bpf_prog_inc_misses_counter(link->link.prog);
2808  		err = 1;
2809  		goto out;
2810  	}
2811  
2812  	migrate_disable();
2813  	rcu_read_lock();
2814  	regs = ftrace_partial_regs(fregs, bpf_kprobe_multi_pt_regs_ptr());
2815  	old_run_ctx = bpf_set_run_ctx(&run_ctx.session_ctx.run_ctx);
2816  	err = bpf_prog_run(link->link.prog, regs);
2817  	bpf_reset_run_ctx(old_run_ctx);
2818  	rcu_read_unlock();
2819  	migrate_enable();
2820  
2821   out:
2822  	__this_cpu_dec(bpf_prog_active);
2823  	return err;
2824  }
2825  
2826  static int
kprobe_multi_link_handler(struct fprobe * fp,unsigned long fentry_ip,unsigned long ret_ip,struct ftrace_regs * fregs,void * data)2827  kprobe_multi_link_handler(struct fprobe *fp, unsigned long fentry_ip,
2828  			  unsigned long ret_ip, struct ftrace_regs *fregs,
2829  			  void *data)
2830  {
2831  	struct bpf_kprobe_multi_link *link;
2832  	int err;
2833  
2834  	link = container_of(fp, struct bpf_kprobe_multi_link, fp);
2835  	err = kprobe_multi_link_prog_run(link, ftrace_get_entry_ip(fentry_ip),
2836  					 fregs, false, data);
2837  	return is_kprobe_session(link->link.prog) ? err : 0;
2838  }
2839  
2840  static void
kprobe_multi_link_exit_handler(struct fprobe * fp,unsigned long fentry_ip,unsigned long ret_ip,struct ftrace_regs * fregs,void * data)2841  kprobe_multi_link_exit_handler(struct fprobe *fp, unsigned long fentry_ip,
2842  			       unsigned long ret_ip, struct ftrace_regs *fregs,
2843  			       void *data)
2844  {
2845  	struct bpf_kprobe_multi_link *link;
2846  
2847  	link = container_of(fp, struct bpf_kprobe_multi_link, fp);
2848  	kprobe_multi_link_prog_run(link, ftrace_get_entry_ip(fentry_ip),
2849  				   fregs, true, data);
2850  }
2851  
symbols_cmp_r(const void * a,const void * b,const void * priv)2852  static int symbols_cmp_r(const void *a, const void *b, const void *priv)
2853  {
2854  	const char **str_a = (const char **) a;
2855  	const char **str_b = (const char **) b;
2856  
2857  	return strcmp(*str_a, *str_b);
2858  }
2859  
2860  struct multi_symbols_sort {
2861  	const char **funcs;
2862  	u64 *cookies;
2863  };
2864  
symbols_swap_r(void * a,void * b,int size,const void * priv)2865  static void symbols_swap_r(void *a, void *b, int size, const void *priv)
2866  {
2867  	const struct multi_symbols_sort *data = priv;
2868  	const char **name_a = a, **name_b = b;
2869  
2870  	swap(*name_a, *name_b);
2871  
2872  	/* If defined, swap also related cookies. */
2873  	if (data->cookies) {
2874  		u64 *cookie_a, *cookie_b;
2875  
2876  		cookie_a = data->cookies + (name_a - data->funcs);
2877  		cookie_b = data->cookies + (name_b - data->funcs);
2878  		swap(*cookie_a, *cookie_b);
2879  	}
2880  }
2881  
2882  struct modules_array {
2883  	struct module **mods;
2884  	int mods_cnt;
2885  	int mods_cap;
2886  };
2887  
add_module(struct modules_array * arr,struct module * mod)2888  static int add_module(struct modules_array *arr, struct module *mod)
2889  {
2890  	struct module **mods;
2891  
2892  	if (arr->mods_cnt == arr->mods_cap) {
2893  		arr->mods_cap = max(16, arr->mods_cap * 3 / 2);
2894  		mods = krealloc_array(arr->mods, arr->mods_cap, sizeof(*mods), GFP_KERNEL);
2895  		if (!mods)
2896  			return -ENOMEM;
2897  		arr->mods = mods;
2898  	}
2899  
2900  	arr->mods[arr->mods_cnt] = mod;
2901  	arr->mods_cnt++;
2902  	return 0;
2903  }
2904  
has_module(struct modules_array * arr,struct module * mod)2905  static bool has_module(struct modules_array *arr, struct module *mod)
2906  {
2907  	int i;
2908  
2909  	for (i = arr->mods_cnt - 1; i >= 0; i--) {
2910  		if (arr->mods[i] == mod)
2911  			return true;
2912  	}
2913  	return false;
2914  }
2915  
get_modules_for_addrs(struct module *** mods,unsigned long * addrs,u32 addrs_cnt)2916  static int get_modules_for_addrs(struct module ***mods, unsigned long *addrs, u32 addrs_cnt)
2917  {
2918  	struct modules_array arr = {};
2919  	u32 i, err = 0;
2920  
2921  	for (i = 0; i < addrs_cnt; i++) {
2922  		struct module *mod;
2923  
2924  		preempt_disable();
2925  		mod = __module_address(addrs[i]);
2926  		/* Either no module or we it's already stored  */
2927  		if (!mod || has_module(&arr, mod)) {
2928  			preempt_enable();
2929  			continue;
2930  		}
2931  		if (!try_module_get(mod))
2932  			err = -EINVAL;
2933  		preempt_enable();
2934  		if (err)
2935  			break;
2936  		err = add_module(&arr, mod);
2937  		if (err) {
2938  			module_put(mod);
2939  			break;
2940  		}
2941  	}
2942  
2943  	/* We return either err < 0 in case of error, ... */
2944  	if (err) {
2945  		kprobe_multi_put_modules(arr.mods, arr.mods_cnt);
2946  		kfree(arr.mods);
2947  		return err;
2948  	}
2949  
2950  	/* or number of modules found if everything is ok. */
2951  	*mods = arr.mods;
2952  	return arr.mods_cnt;
2953  }
2954  
addrs_check_error_injection_list(unsigned long * addrs,u32 cnt)2955  static int addrs_check_error_injection_list(unsigned long *addrs, u32 cnt)
2956  {
2957  	u32 i;
2958  
2959  	for (i = 0; i < cnt; i++) {
2960  		if (!within_error_injection_list(addrs[i]))
2961  			return -EINVAL;
2962  	}
2963  	return 0;
2964  }
2965  
bpf_kprobe_multi_link_attach(const union bpf_attr * attr,struct bpf_prog * prog)2966  int bpf_kprobe_multi_link_attach(const union bpf_attr *attr, struct bpf_prog *prog)
2967  {
2968  	struct bpf_kprobe_multi_link *link = NULL;
2969  	struct bpf_link_primer link_primer;
2970  	void __user *ucookies;
2971  	unsigned long *addrs;
2972  	u32 flags, cnt, size;
2973  	void __user *uaddrs;
2974  	u64 *cookies = NULL;
2975  	void __user *usyms;
2976  	int err;
2977  
2978  	/* no support for 32bit archs yet */
2979  	if (sizeof(u64) != sizeof(void *))
2980  		return -EOPNOTSUPP;
2981  
2982  	if (!is_kprobe_multi(prog))
2983  		return -EINVAL;
2984  
2985  	flags = attr->link_create.kprobe_multi.flags;
2986  	if (flags & ~BPF_F_KPROBE_MULTI_RETURN)
2987  		return -EINVAL;
2988  
2989  	uaddrs = u64_to_user_ptr(attr->link_create.kprobe_multi.addrs);
2990  	usyms = u64_to_user_ptr(attr->link_create.kprobe_multi.syms);
2991  	if (!!uaddrs == !!usyms)
2992  		return -EINVAL;
2993  
2994  	cnt = attr->link_create.kprobe_multi.cnt;
2995  	if (!cnt)
2996  		return -EINVAL;
2997  	if (cnt > MAX_KPROBE_MULTI_CNT)
2998  		return -E2BIG;
2999  
3000  	size = cnt * sizeof(*addrs);
3001  	addrs = kvmalloc_array(cnt, sizeof(*addrs), GFP_KERNEL);
3002  	if (!addrs)
3003  		return -ENOMEM;
3004  
3005  	ucookies = u64_to_user_ptr(attr->link_create.kprobe_multi.cookies);
3006  	if (ucookies) {
3007  		cookies = kvmalloc_array(cnt, sizeof(*addrs), GFP_KERNEL);
3008  		if (!cookies) {
3009  			err = -ENOMEM;
3010  			goto error;
3011  		}
3012  		if (copy_from_user(cookies, ucookies, size)) {
3013  			err = -EFAULT;
3014  			goto error;
3015  		}
3016  	}
3017  
3018  	if (uaddrs) {
3019  		if (copy_from_user(addrs, uaddrs, size)) {
3020  			err = -EFAULT;
3021  			goto error;
3022  		}
3023  	} else {
3024  		struct multi_symbols_sort data = {
3025  			.cookies = cookies,
3026  		};
3027  		struct user_syms us;
3028  
3029  		err = copy_user_syms(&us, usyms, cnt);
3030  		if (err)
3031  			goto error;
3032  
3033  		if (cookies)
3034  			data.funcs = us.syms;
3035  
3036  		sort_r(us.syms, cnt, sizeof(*us.syms), symbols_cmp_r,
3037  		       symbols_swap_r, &data);
3038  
3039  		err = ftrace_lookup_symbols(us.syms, cnt, addrs);
3040  		free_user_syms(&us);
3041  		if (err)
3042  			goto error;
3043  	}
3044  
3045  	if (prog->kprobe_override && addrs_check_error_injection_list(addrs, cnt)) {
3046  		err = -EINVAL;
3047  		goto error;
3048  	}
3049  
3050  	link = kzalloc(sizeof(*link), GFP_KERNEL);
3051  	if (!link) {
3052  		err = -ENOMEM;
3053  		goto error;
3054  	}
3055  
3056  	bpf_link_init(&link->link, BPF_LINK_TYPE_KPROBE_MULTI,
3057  		      &bpf_kprobe_multi_link_lops, prog);
3058  
3059  	err = bpf_link_prime(&link->link, &link_primer);
3060  	if (err)
3061  		goto error;
3062  
3063  	if (!(flags & BPF_F_KPROBE_MULTI_RETURN))
3064  		link->fp.entry_handler = kprobe_multi_link_handler;
3065  	if ((flags & BPF_F_KPROBE_MULTI_RETURN) || is_kprobe_session(prog))
3066  		link->fp.exit_handler = kprobe_multi_link_exit_handler;
3067  	if (is_kprobe_session(prog))
3068  		link->fp.entry_data_size = sizeof(u64);
3069  
3070  	link->addrs = addrs;
3071  	link->cookies = cookies;
3072  	link->cnt = cnt;
3073  	link->flags = flags;
3074  
3075  	if (cookies) {
3076  		/*
3077  		 * Sorting addresses will trigger sorting cookies as well
3078  		 * (check bpf_kprobe_multi_cookie_swap). This way we can
3079  		 * find cookie based on the address in bpf_get_attach_cookie
3080  		 * helper.
3081  		 */
3082  		sort_r(addrs, cnt, sizeof(*addrs),
3083  		       bpf_kprobe_multi_cookie_cmp,
3084  		       bpf_kprobe_multi_cookie_swap,
3085  		       link);
3086  	}
3087  
3088  	err = get_modules_for_addrs(&link->mods, addrs, cnt);
3089  	if (err < 0) {
3090  		bpf_link_cleanup(&link_primer);
3091  		return err;
3092  	}
3093  	link->mods_cnt = err;
3094  
3095  	err = register_fprobe_ips(&link->fp, addrs, cnt);
3096  	if (err) {
3097  		kprobe_multi_put_modules(link->mods, link->mods_cnt);
3098  		bpf_link_cleanup(&link_primer);
3099  		return err;
3100  	}
3101  
3102  	return bpf_link_settle(&link_primer);
3103  
3104  error:
3105  	kfree(link);
3106  	kvfree(addrs);
3107  	kvfree(cookies);
3108  	return err;
3109  }
3110  #else /* !CONFIG_FPROBE */
bpf_kprobe_multi_link_attach(const union bpf_attr * attr,struct bpf_prog * prog)3111  int bpf_kprobe_multi_link_attach(const union bpf_attr *attr, struct bpf_prog *prog)
3112  {
3113  	return -EOPNOTSUPP;
3114  }
bpf_kprobe_multi_cookie(struct bpf_run_ctx * ctx)3115  static u64 bpf_kprobe_multi_cookie(struct bpf_run_ctx *ctx)
3116  {
3117  	return 0;
3118  }
bpf_kprobe_multi_entry_ip(struct bpf_run_ctx * ctx)3119  static u64 bpf_kprobe_multi_entry_ip(struct bpf_run_ctx *ctx)
3120  {
3121  	return 0;
3122  }
3123  #endif
3124  
3125  #ifdef CONFIG_UPROBES
3126  struct bpf_uprobe_multi_link;
3127  
3128  struct bpf_uprobe {
3129  	struct bpf_uprobe_multi_link *link;
3130  	loff_t offset;
3131  	unsigned long ref_ctr_offset;
3132  	u64 cookie;
3133  	struct uprobe *uprobe;
3134  	struct uprobe_consumer consumer;
3135  	bool session;
3136  };
3137  
3138  struct bpf_uprobe_multi_link {
3139  	struct path path;
3140  	struct bpf_link link;
3141  	u32 cnt;
3142  	u32 flags;
3143  	struct bpf_uprobe *uprobes;
3144  	struct task_struct *task;
3145  };
3146  
3147  struct bpf_uprobe_multi_run_ctx {
3148  	struct bpf_session_run_ctx session_ctx;
3149  	unsigned long entry_ip;
3150  	struct bpf_uprobe *uprobe;
3151  };
3152  
bpf_uprobe_unregister(struct bpf_uprobe * uprobes,u32 cnt)3153  static void bpf_uprobe_unregister(struct bpf_uprobe *uprobes, u32 cnt)
3154  {
3155  	u32 i;
3156  
3157  	for (i = 0; i < cnt; i++)
3158  		uprobe_unregister_nosync(uprobes[i].uprobe, &uprobes[i].consumer);
3159  
3160  	if (cnt)
3161  		uprobe_unregister_sync();
3162  }
3163  
bpf_uprobe_multi_link_release(struct bpf_link * link)3164  static void bpf_uprobe_multi_link_release(struct bpf_link *link)
3165  {
3166  	struct bpf_uprobe_multi_link *umulti_link;
3167  
3168  	umulti_link = container_of(link, struct bpf_uprobe_multi_link, link);
3169  	bpf_uprobe_unregister(umulti_link->uprobes, umulti_link->cnt);
3170  	if (umulti_link->task)
3171  		put_task_struct(umulti_link->task);
3172  	path_put(&umulti_link->path);
3173  }
3174  
bpf_uprobe_multi_link_dealloc(struct bpf_link * link)3175  static void bpf_uprobe_multi_link_dealloc(struct bpf_link *link)
3176  {
3177  	struct bpf_uprobe_multi_link *umulti_link;
3178  
3179  	umulti_link = container_of(link, struct bpf_uprobe_multi_link, link);
3180  	kvfree(umulti_link->uprobes);
3181  	kfree(umulti_link);
3182  }
3183  
bpf_uprobe_multi_link_fill_link_info(const struct bpf_link * link,struct bpf_link_info * info)3184  static int bpf_uprobe_multi_link_fill_link_info(const struct bpf_link *link,
3185  						struct bpf_link_info *info)
3186  {
3187  	u64 __user *uref_ctr_offsets = u64_to_user_ptr(info->uprobe_multi.ref_ctr_offsets);
3188  	u64 __user *ucookies = u64_to_user_ptr(info->uprobe_multi.cookies);
3189  	u64 __user *uoffsets = u64_to_user_ptr(info->uprobe_multi.offsets);
3190  	u64 __user *upath = u64_to_user_ptr(info->uprobe_multi.path);
3191  	u32 upath_size = info->uprobe_multi.path_size;
3192  	struct bpf_uprobe_multi_link *umulti_link;
3193  	u32 ucount = info->uprobe_multi.count;
3194  	int err = 0, i;
3195  	char *p, *buf;
3196  	long left = 0;
3197  
3198  	if (!upath ^ !upath_size)
3199  		return -EINVAL;
3200  
3201  	if ((uoffsets || uref_ctr_offsets || ucookies) && !ucount)
3202  		return -EINVAL;
3203  
3204  	umulti_link = container_of(link, struct bpf_uprobe_multi_link, link);
3205  	info->uprobe_multi.count = umulti_link->cnt;
3206  	info->uprobe_multi.flags = umulti_link->flags;
3207  	info->uprobe_multi.pid = umulti_link->task ?
3208  				 task_pid_nr_ns(umulti_link->task, task_active_pid_ns(current)) : 0;
3209  
3210  	upath_size = upath_size ? min_t(u32, upath_size, PATH_MAX) : PATH_MAX;
3211  	buf = kmalloc(upath_size, GFP_KERNEL);
3212  	if (!buf)
3213  		return -ENOMEM;
3214  	p = d_path(&umulti_link->path, buf, upath_size);
3215  	if (IS_ERR(p)) {
3216  		kfree(buf);
3217  		return PTR_ERR(p);
3218  	}
3219  	upath_size = buf + upath_size - p;
3220  
3221  	if (upath)
3222  		left = copy_to_user(upath, p, upath_size);
3223  	kfree(buf);
3224  	if (left)
3225  		return -EFAULT;
3226  	info->uprobe_multi.path_size = upath_size;
3227  
3228  	if (!uoffsets && !ucookies && !uref_ctr_offsets)
3229  		return 0;
3230  
3231  	if (ucount < umulti_link->cnt)
3232  		err = -ENOSPC;
3233  	else
3234  		ucount = umulti_link->cnt;
3235  
3236  	for (i = 0; i < ucount; i++) {
3237  		if (uoffsets &&
3238  		    put_user(umulti_link->uprobes[i].offset, uoffsets + i))
3239  			return -EFAULT;
3240  		if (uref_ctr_offsets &&
3241  		    put_user(umulti_link->uprobes[i].ref_ctr_offset, uref_ctr_offsets + i))
3242  			return -EFAULT;
3243  		if (ucookies &&
3244  		    put_user(umulti_link->uprobes[i].cookie, ucookies + i))
3245  			return -EFAULT;
3246  	}
3247  
3248  	return err;
3249  }
3250  
3251  static const struct bpf_link_ops bpf_uprobe_multi_link_lops = {
3252  	.release = bpf_uprobe_multi_link_release,
3253  	.dealloc_deferred = bpf_uprobe_multi_link_dealloc,
3254  	.fill_link_info = bpf_uprobe_multi_link_fill_link_info,
3255  };
3256  
uprobe_prog_run(struct bpf_uprobe * uprobe,unsigned long entry_ip,struct pt_regs * regs,bool is_return,void * data)3257  static int uprobe_prog_run(struct bpf_uprobe *uprobe,
3258  			   unsigned long entry_ip,
3259  			   struct pt_regs *regs,
3260  			   bool is_return, void *data)
3261  {
3262  	struct bpf_uprobe_multi_link *link = uprobe->link;
3263  	struct bpf_uprobe_multi_run_ctx run_ctx = {
3264  		.session_ctx = {
3265  			.is_return = is_return,
3266  			.data = data,
3267  		},
3268  		.entry_ip = entry_ip,
3269  		.uprobe = uprobe,
3270  	};
3271  	struct bpf_prog *prog = link->link.prog;
3272  	bool sleepable = prog->sleepable;
3273  	struct bpf_run_ctx *old_run_ctx;
3274  	int err;
3275  
3276  	if (link->task && !same_thread_group(current, link->task))
3277  		return 0;
3278  
3279  	if (sleepable)
3280  		rcu_read_lock_trace();
3281  	else
3282  		rcu_read_lock();
3283  
3284  	migrate_disable();
3285  
3286  	old_run_ctx = bpf_set_run_ctx(&run_ctx.session_ctx.run_ctx);
3287  	err = bpf_prog_run(link->link.prog, regs);
3288  	bpf_reset_run_ctx(old_run_ctx);
3289  
3290  	migrate_enable();
3291  
3292  	if (sleepable)
3293  		rcu_read_unlock_trace();
3294  	else
3295  		rcu_read_unlock();
3296  	return err;
3297  }
3298  
3299  static bool
uprobe_multi_link_filter(struct uprobe_consumer * con,struct mm_struct * mm)3300  uprobe_multi_link_filter(struct uprobe_consumer *con, struct mm_struct *mm)
3301  {
3302  	struct bpf_uprobe *uprobe;
3303  
3304  	uprobe = container_of(con, struct bpf_uprobe, consumer);
3305  	return uprobe->link->task->mm == mm;
3306  }
3307  
3308  static int
uprobe_multi_link_handler(struct uprobe_consumer * con,struct pt_regs * regs,__u64 * data)3309  uprobe_multi_link_handler(struct uprobe_consumer *con, struct pt_regs *regs,
3310  			  __u64 *data)
3311  {
3312  	struct bpf_uprobe *uprobe;
3313  	int ret;
3314  
3315  	uprobe = container_of(con, struct bpf_uprobe, consumer);
3316  	ret = uprobe_prog_run(uprobe, instruction_pointer(regs), regs, false, data);
3317  	if (uprobe->session)
3318  		return ret ? UPROBE_HANDLER_IGNORE : 0;
3319  	return 0;
3320  }
3321  
3322  static int
uprobe_multi_link_ret_handler(struct uprobe_consumer * con,unsigned long func,struct pt_regs * regs,__u64 * data)3323  uprobe_multi_link_ret_handler(struct uprobe_consumer *con, unsigned long func, struct pt_regs *regs,
3324  			      __u64 *data)
3325  {
3326  	struct bpf_uprobe *uprobe;
3327  
3328  	uprobe = container_of(con, struct bpf_uprobe, consumer);
3329  	uprobe_prog_run(uprobe, func, regs, true, data);
3330  	return 0;
3331  }
3332  
bpf_uprobe_multi_entry_ip(struct bpf_run_ctx * ctx)3333  static u64 bpf_uprobe_multi_entry_ip(struct bpf_run_ctx *ctx)
3334  {
3335  	struct bpf_uprobe_multi_run_ctx *run_ctx;
3336  
3337  	run_ctx = container_of(current->bpf_ctx, struct bpf_uprobe_multi_run_ctx,
3338  			       session_ctx.run_ctx);
3339  	return run_ctx->entry_ip;
3340  }
3341  
bpf_uprobe_multi_cookie(struct bpf_run_ctx * ctx)3342  static u64 bpf_uprobe_multi_cookie(struct bpf_run_ctx *ctx)
3343  {
3344  	struct bpf_uprobe_multi_run_ctx *run_ctx;
3345  
3346  	run_ctx = container_of(current->bpf_ctx, struct bpf_uprobe_multi_run_ctx,
3347  			       session_ctx.run_ctx);
3348  	return run_ctx->uprobe->cookie;
3349  }
3350  
bpf_uprobe_multi_link_attach(const union bpf_attr * attr,struct bpf_prog * prog)3351  int bpf_uprobe_multi_link_attach(const union bpf_attr *attr, struct bpf_prog *prog)
3352  {
3353  	struct bpf_uprobe_multi_link *link = NULL;
3354  	unsigned long __user *uref_ctr_offsets;
3355  	struct bpf_link_primer link_primer;
3356  	struct bpf_uprobe *uprobes = NULL;
3357  	struct task_struct *task = NULL;
3358  	unsigned long __user *uoffsets;
3359  	u64 __user *ucookies;
3360  	void __user *upath;
3361  	u32 flags, cnt, i;
3362  	struct path path;
3363  	char *name;
3364  	pid_t pid;
3365  	int err;
3366  
3367  	/* no support for 32bit archs yet */
3368  	if (sizeof(u64) != sizeof(void *))
3369  		return -EOPNOTSUPP;
3370  
3371  	if (!is_uprobe_multi(prog))
3372  		return -EINVAL;
3373  
3374  	flags = attr->link_create.uprobe_multi.flags;
3375  	if (flags & ~BPF_F_UPROBE_MULTI_RETURN)
3376  		return -EINVAL;
3377  
3378  	/*
3379  	 * path, offsets and cnt are mandatory,
3380  	 * ref_ctr_offsets and cookies are optional
3381  	 */
3382  	upath = u64_to_user_ptr(attr->link_create.uprobe_multi.path);
3383  	uoffsets = u64_to_user_ptr(attr->link_create.uprobe_multi.offsets);
3384  	cnt = attr->link_create.uprobe_multi.cnt;
3385  	pid = attr->link_create.uprobe_multi.pid;
3386  
3387  	if (!upath || !uoffsets || !cnt || pid < 0)
3388  		return -EINVAL;
3389  	if (cnt > MAX_UPROBE_MULTI_CNT)
3390  		return -E2BIG;
3391  
3392  	uref_ctr_offsets = u64_to_user_ptr(attr->link_create.uprobe_multi.ref_ctr_offsets);
3393  	ucookies = u64_to_user_ptr(attr->link_create.uprobe_multi.cookies);
3394  
3395  	name = strndup_user(upath, PATH_MAX);
3396  	if (IS_ERR(name)) {
3397  		err = PTR_ERR(name);
3398  		return err;
3399  	}
3400  
3401  	err = kern_path(name, LOOKUP_FOLLOW, &path);
3402  	kfree(name);
3403  	if (err)
3404  		return err;
3405  
3406  	if (!d_is_reg(path.dentry)) {
3407  		err = -EBADF;
3408  		goto error_path_put;
3409  	}
3410  
3411  	if (pid) {
3412  		task = get_pid_task(find_vpid(pid), PIDTYPE_TGID);
3413  		if (!task) {
3414  			err = -ESRCH;
3415  			goto error_path_put;
3416  		}
3417  	}
3418  
3419  	err = -ENOMEM;
3420  
3421  	link = kzalloc(sizeof(*link), GFP_KERNEL);
3422  	uprobes = kvcalloc(cnt, sizeof(*uprobes), GFP_KERNEL);
3423  
3424  	if (!uprobes || !link)
3425  		goto error_free;
3426  
3427  	for (i = 0; i < cnt; i++) {
3428  		if (__get_user(uprobes[i].offset, uoffsets + i)) {
3429  			err = -EFAULT;
3430  			goto error_free;
3431  		}
3432  		if (uprobes[i].offset < 0) {
3433  			err = -EINVAL;
3434  			goto error_free;
3435  		}
3436  		if (uref_ctr_offsets && __get_user(uprobes[i].ref_ctr_offset, uref_ctr_offsets + i)) {
3437  			err = -EFAULT;
3438  			goto error_free;
3439  		}
3440  		if (ucookies && __get_user(uprobes[i].cookie, ucookies + i)) {
3441  			err = -EFAULT;
3442  			goto error_free;
3443  		}
3444  
3445  		uprobes[i].link = link;
3446  
3447  		if (!(flags & BPF_F_UPROBE_MULTI_RETURN))
3448  			uprobes[i].consumer.handler = uprobe_multi_link_handler;
3449  		if (flags & BPF_F_UPROBE_MULTI_RETURN || is_uprobe_session(prog))
3450  			uprobes[i].consumer.ret_handler = uprobe_multi_link_ret_handler;
3451  		if (is_uprobe_session(prog))
3452  			uprobes[i].session = true;
3453  		if (pid)
3454  			uprobes[i].consumer.filter = uprobe_multi_link_filter;
3455  	}
3456  
3457  	link->cnt = cnt;
3458  	link->uprobes = uprobes;
3459  	link->path = path;
3460  	link->task = task;
3461  	link->flags = flags;
3462  
3463  	bpf_link_init(&link->link, BPF_LINK_TYPE_UPROBE_MULTI,
3464  		      &bpf_uprobe_multi_link_lops, prog);
3465  
3466  	for (i = 0; i < cnt; i++) {
3467  		uprobes[i].uprobe = uprobe_register(d_real_inode(link->path.dentry),
3468  						    uprobes[i].offset,
3469  						    uprobes[i].ref_ctr_offset,
3470  						    &uprobes[i].consumer);
3471  		if (IS_ERR(uprobes[i].uprobe)) {
3472  			err = PTR_ERR(uprobes[i].uprobe);
3473  			link->cnt = i;
3474  			goto error_unregister;
3475  		}
3476  	}
3477  
3478  	err = bpf_link_prime(&link->link, &link_primer);
3479  	if (err)
3480  		goto error_unregister;
3481  
3482  	return bpf_link_settle(&link_primer);
3483  
3484  error_unregister:
3485  	bpf_uprobe_unregister(uprobes, link->cnt);
3486  
3487  error_free:
3488  	kvfree(uprobes);
3489  	kfree(link);
3490  	if (task)
3491  		put_task_struct(task);
3492  error_path_put:
3493  	path_put(&path);
3494  	return err;
3495  }
3496  #else /* !CONFIG_UPROBES */
bpf_uprobe_multi_link_attach(const union bpf_attr * attr,struct bpf_prog * prog)3497  int bpf_uprobe_multi_link_attach(const union bpf_attr *attr, struct bpf_prog *prog)
3498  {
3499  	return -EOPNOTSUPP;
3500  }
bpf_uprobe_multi_cookie(struct bpf_run_ctx * ctx)3501  static u64 bpf_uprobe_multi_cookie(struct bpf_run_ctx *ctx)
3502  {
3503  	return 0;
3504  }
bpf_uprobe_multi_entry_ip(struct bpf_run_ctx * ctx)3505  static u64 bpf_uprobe_multi_entry_ip(struct bpf_run_ctx *ctx)
3506  {
3507  	return 0;
3508  }
3509  #endif /* CONFIG_UPROBES */
3510  
3511  __bpf_kfunc_start_defs();
3512  
bpf_session_is_return(void)3513  __bpf_kfunc bool bpf_session_is_return(void)
3514  {
3515  	struct bpf_session_run_ctx *session_ctx;
3516  
3517  	session_ctx = container_of(current->bpf_ctx, struct bpf_session_run_ctx, run_ctx);
3518  	return session_ctx->is_return;
3519  }
3520  
bpf_session_cookie(void)3521  __bpf_kfunc __u64 *bpf_session_cookie(void)
3522  {
3523  	struct bpf_session_run_ctx *session_ctx;
3524  
3525  	session_ctx = container_of(current->bpf_ctx, struct bpf_session_run_ctx, run_ctx);
3526  	return session_ctx->data;
3527  }
3528  
3529  __bpf_kfunc_end_defs();
3530  
3531  BTF_KFUNCS_START(kprobe_multi_kfunc_set_ids)
BTF_ID_FLAGS(func,bpf_session_is_return)3532  BTF_ID_FLAGS(func, bpf_session_is_return)
3533  BTF_ID_FLAGS(func, bpf_session_cookie)
3534  BTF_KFUNCS_END(kprobe_multi_kfunc_set_ids)
3535  
3536  static int bpf_kprobe_multi_filter(const struct bpf_prog *prog, u32 kfunc_id)
3537  {
3538  	if (!btf_id_set8_contains(&kprobe_multi_kfunc_set_ids, kfunc_id))
3539  		return 0;
3540  
3541  	if (!is_kprobe_session(prog) && !is_uprobe_session(prog))
3542  		return -EACCES;
3543  
3544  	return 0;
3545  }
3546  
3547  static const struct btf_kfunc_id_set bpf_kprobe_multi_kfunc_set = {
3548  	.owner = THIS_MODULE,
3549  	.set = &kprobe_multi_kfunc_set_ids,
3550  	.filter = bpf_kprobe_multi_filter,
3551  };
3552  
bpf_kprobe_multi_kfuncs_init(void)3553  static int __init bpf_kprobe_multi_kfuncs_init(void)
3554  {
3555  	return register_btf_kfunc_id_set(BPF_PROG_TYPE_KPROBE, &bpf_kprobe_multi_kfunc_set);
3556  }
3557  
3558  late_initcall(bpf_kprobe_multi_kfuncs_init);
3559  
3560  __bpf_kfunc_start_defs();
3561  
bpf_send_signal_task(struct task_struct * task,int sig,enum pid_type type,u64 value)3562  __bpf_kfunc int bpf_send_signal_task(struct task_struct *task, int sig, enum pid_type type,
3563  				     u64 value)
3564  {
3565  	if (type != PIDTYPE_PID && type != PIDTYPE_TGID)
3566  		return -EINVAL;
3567  
3568  	return bpf_send_signal_common(sig, type, task, value);
3569  }
3570  
3571  __bpf_kfunc_end_defs();
3572