1  // SPDX-License-Identifier: GPL-2.0-or-later
2  /*
3   * Linux Socket Filter - Kernel level socket filtering
4   *
5   * Based on the design of the Berkeley Packet Filter. The new
6   * internal format has been designed by PLUMgrid:
7   *
8   *	Copyright (c) 2011 - 2014 PLUMgrid, http://plumgrid.com
9   *
10   * Authors:
11   *
12   *	Jay Schulist <jschlst@samba.org>
13   *	Alexei Starovoitov <ast@plumgrid.com>
14   *	Daniel Borkmann <dborkman@redhat.com>
15   *
16   * Andi Kleen - Fix a few bad bugs and races.
17   * Kris Katterjohn - Added many additional checks in bpf_check_classic()
18   */
19  
20  #include <uapi/linux/btf.h>
21  #include <linux/filter.h>
22  #include <linux/skbuff.h>
23  #include <linux/vmalloc.h>
24  #include <linux/random.h>
25  #include <linux/bpf.h>
26  #include <linux/btf.h>
27  #include <linux/objtool.h>
28  #include <linux/overflow.h>
29  #include <linux/rbtree_latch.h>
30  #include <linux/kallsyms.h>
31  #include <linux/rcupdate.h>
32  #include <linux/perf_event.h>
33  #include <linux/extable.h>
34  #include <linux/log2.h>
35  #include <linux/bpf_verifier.h>
36  #include <linux/nodemask.h>
37  #include <linux/nospec.h>
38  #include <linux/bpf_mem_alloc.h>
39  #include <linux/memcontrol.h>
40  #include <linux/execmem.h>
41  
42  #include <asm/barrier.h>
43  #include <linux/unaligned.h>
44  
45  /* Registers */
46  #define BPF_R0	regs[BPF_REG_0]
47  #define BPF_R1	regs[BPF_REG_1]
48  #define BPF_R2	regs[BPF_REG_2]
49  #define BPF_R3	regs[BPF_REG_3]
50  #define BPF_R4	regs[BPF_REG_4]
51  #define BPF_R5	regs[BPF_REG_5]
52  #define BPF_R6	regs[BPF_REG_6]
53  #define BPF_R7	regs[BPF_REG_7]
54  #define BPF_R8	regs[BPF_REG_8]
55  #define BPF_R9	regs[BPF_REG_9]
56  #define BPF_R10	regs[BPF_REG_10]
57  
58  /* Named registers */
59  #define DST	regs[insn->dst_reg]
60  #define SRC	regs[insn->src_reg]
61  #define FP	regs[BPF_REG_FP]
62  #define AX	regs[BPF_REG_AX]
63  #define ARG1	regs[BPF_REG_ARG1]
64  #define CTX	regs[BPF_REG_CTX]
65  #define OFF	insn->off
66  #define IMM	insn->imm
67  
68  struct bpf_mem_alloc bpf_global_ma;
69  bool bpf_global_ma_set;
70  
71  /* No hurry in this branch
72   *
73   * Exported for the bpf jit load helper.
74   */
bpf_internal_load_pointer_neg_helper(const struct sk_buff * skb,int k,unsigned int size)75  void *bpf_internal_load_pointer_neg_helper(const struct sk_buff *skb, int k, unsigned int size)
76  {
77  	u8 *ptr = NULL;
78  
79  	if (k >= SKF_NET_OFF) {
80  		ptr = skb_network_header(skb) + k - SKF_NET_OFF;
81  	} else if (k >= SKF_LL_OFF) {
82  		if (unlikely(!skb_mac_header_was_set(skb)))
83  			return NULL;
84  		ptr = skb_mac_header(skb) + k - SKF_LL_OFF;
85  	}
86  	if (ptr >= skb->head && ptr + size <= skb_tail_pointer(skb))
87  		return ptr;
88  
89  	return NULL;
90  }
91  
92  /* tell bpf programs that include vmlinux.h kernel's PAGE_SIZE */
93  enum page_size_enum {
94  	__PAGE_SIZE = PAGE_SIZE
95  };
96  
bpf_prog_alloc_no_stats(unsigned int size,gfp_t gfp_extra_flags)97  struct bpf_prog *bpf_prog_alloc_no_stats(unsigned int size, gfp_t gfp_extra_flags)
98  {
99  	gfp_t gfp_flags = bpf_memcg_flags(GFP_KERNEL | __GFP_ZERO | gfp_extra_flags);
100  	struct bpf_prog_aux *aux;
101  	struct bpf_prog *fp;
102  
103  	size = round_up(size, __PAGE_SIZE);
104  	fp = __vmalloc(size, gfp_flags);
105  	if (fp == NULL)
106  		return NULL;
107  
108  	aux = kzalloc(sizeof(*aux), bpf_memcg_flags(GFP_KERNEL | gfp_extra_flags));
109  	if (aux == NULL) {
110  		vfree(fp);
111  		return NULL;
112  	}
113  	fp->active = alloc_percpu_gfp(int, bpf_memcg_flags(GFP_KERNEL | gfp_extra_flags));
114  	if (!fp->active) {
115  		vfree(fp);
116  		kfree(aux);
117  		return NULL;
118  	}
119  
120  	fp->pages = size / PAGE_SIZE;
121  	fp->aux = aux;
122  	fp->aux->prog = fp;
123  	fp->jit_requested = ebpf_jit_enabled();
124  	fp->blinding_requested = bpf_jit_blinding_enabled(fp);
125  #ifdef CONFIG_CGROUP_BPF
126  	aux->cgroup_atype = CGROUP_BPF_ATTACH_TYPE_INVALID;
127  #endif
128  
129  	INIT_LIST_HEAD_RCU(&fp->aux->ksym.lnode);
130  #ifdef CONFIG_FINEIBT
131  	INIT_LIST_HEAD_RCU(&fp->aux->ksym_prefix.lnode);
132  #endif
133  	mutex_init(&fp->aux->used_maps_mutex);
134  	mutex_init(&fp->aux->dst_mutex);
135  
136  	return fp;
137  }
138  
bpf_prog_alloc(unsigned int size,gfp_t gfp_extra_flags)139  struct bpf_prog *bpf_prog_alloc(unsigned int size, gfp_t gfp_extra_flags)
140  {
141  	gfp_t gfp_flags = bpf_memcg_flags(GFP_KERNEL | __GFP_ZERO | gfp_extra_flags);
142  	struct bpf_prog *prog;
143  	int cpu;
144  
145  	prog = bpf_prog_alloc_no_stats(size, gfp_extra_flags);
146  	if (!prog)
147  		return NULL;
148  
149  	prog->stats = alloc_percpu_gfp(struct bpf_prog_stats, gfp_flags);
150  	if (!prog->stats) {
151  		free_percpu(prog->active);
152  		kfree(prog->aux);
153  		vfree(prog);
154  		return NULL;
155  	}
156  
157  	for_each_possible_cpu(cpu) {
158  		struct bpf_prog_stats *pstats;
159  
160  		pstats = per_cpu_ptr(prog->stats, cpu);
161  		u64_stats_init(&pstats->syncp);
162  	}
163  	return prog;
164  }
165  EXPORT_SYMBOL_GPL(bpf_prog_alloc);
166  
bpf_prog_alloc_jited_linfo(struct bpf_prog * prog)167  int bpf_prog_alloc_jited_linfo(struct bpf_prog *prog)
168  {
169  	if (!prog->aux->nr_linfo || !prog->jit_requested)
170  		return 0;
171  
172  	prog->aux->jited_linfo = kvcalloc(prog->aux->nr_linfo,
173  					  sizeof(*prog->aux->jited_linfo),
174  					  bpf_memcg_flags(GFP_KERNEL | __GFP_NOWARN));
175  	if (!prog->aux->jited_linfo)
176  		return -ENOMEM;
177  
178  	return 0;
179  }
180  
bpf_prog_jit_attempt_done(struct bpf_prog * prog)181  void bpf_prog_jit_attempt_done(struct bpf_prog *prog)
182  {
183  	if (prog->aux->jited_linfo &&
184  	    (!prog->jited || !prog->aux->jited_linfo[0])) {
185  		kvfree(prog->aux->jited_linfo);
186  		prog->aux->jited_linfo = NULL;
187  	}
188  
189  	kfree(prog->aux->kfunc_tab);
190  	prog->aux->kfunc_tab = NULL;
191  }
192  
193  /* The jit engine is responsible to provide an array
194   * for insn_off to the jited_off mapping (insn_to_jit_off).
195   *
196   * The idx to this array is the insn_off.  Hence, the insn_off
197   * here is relative to the prog itself instead of the main prog.
198   * This array has one entry for each xlated bpf insn.
199   *
200   * jited_off is the byte off to the end of the jited insn.
201   *
202   * Hence, with
203   * insn_start:
204   *      The first bpf insn off of the prog.  The insn off
205   *      here is relative to the main prog.
206   *      e.g. if prog is a subprog, insn_start > 0
207   * linfo_idx:
208   *      The prog's idx to prog->aux->linfo and jited_linfo
209   *
210   * jited_linfo[linfo_idx] = prog->bpf_func
211   *
212   * For i > linfo_idx,
213   *
214   * jited_linfo[i] = prog->bpf_func +
215   *	insn_to_jit_off[linfo[i].insn_off - insn_start - 1]
216   */
bpf_prog_fill_jited_linfo(struct bpf_prog * prog,const u32 * insn_to_jit_off)217  void bpf_prog_fill_jited_linfo(struct bpf_prog *prog,
218  			       const u32 *insn_to_jit_off)
219  {
220  	u32 linfo_idx, insn_start, insn_end, nr_linfo, i;
221  	const struct bpf_line_info *linfo;
222  	void **jited_linfo;
223  
224  	if (!prog->aux->jited_linfo || prog->aux->func_idx > prog->aux->func_cnt)
225  		/* Userspace did not provide linfo */
226  		return;
227  
228  	linfo_idx = prog->aux->linfo_idx;
229  	linfo = &prog->aux->linfo[linfo_idx];
230  	insn_start = linfo[0].insn_off;
231  	insn_end = insn_start + prog->len;
232  
233  	jited_linfo = &prog->aux->jited_linfo[linfo_idx];
234  	jited_linfo[0] = prog->bpf_func;
235  
236  	nr_linfo = prog->aux->nr_linfo - linfo_idx;
237  
238  	for (i = 1; i < nr_linfo && linfo[i].insn_off < insn_end; i++)
239  		/* The verifier ensures that linfo[i].insn_off is
240  		 * strictly increasing
241  		 */
242  		jited_linfo[i] = prog->bpf_func +
243  			insn_to_jit_off[linfo[i].insn_off - insn_start - 1];
244  }
245  
bpf_prog_realloc(struct bpf_prog * fp_old,unsigned int size,gfp_t gfp_extra_flags)246  struct bpf_prog *bpf_prog_realloc(struct bpf_prog *fp_old, unsigned int size,
247  				  gfp_t gfp_extra_flags)
248  {
249  	gfp_t gfp_flags = bpf_memcg_flags(GFP_KERNEL | __GFP_ZERO | gfp_extra_flags);
250  	struct bpf_prog *fp;
251  	u32 pages;
252  
253  	size = round_up(size, PAGE_SIZE);
254  	pages = size / PAGE_SIZE;
255  	if (pages <= fp_old->pages)
256  		return fp_old;
257  
258  	fp = __vmalloc(size, gfp_flags);
259  	if (fp) {
260  		memcpy(fp, fp_old, fp_old->pages * PAGE_SIZE);
261  		fp->pages = pages;
262  		fp->aux->prog = fp;
263  
264  		/* We keep fp->aux from fp_old around in the new
265  		 * reallocated structure.
266  		 */
267  		fp_old->aux = NULL;
268  		fp_old->stats = NULL;
269  		fp_old->active = NULL;
270  		__bpf_prog_free(fp_old);
271  	}
272  
273  	return fp;
274  }
275  
__bpf_prog_free(struct bpf_prog * fp)276  void __bpf_prog_free(struct bpf_prog *fp)
277  {
278  	if (fp->aux) {
279  		mutex_destroy(&fp->aux->used_maps_mutex);
280  		mutex_destroy(&fp->aux->dst_mutex);
281  		kfree(fp->aux->poke_tab);
282  		kfree(fp->aux);
283  	}
284  	free_percpu(fp->stats);
285  	free_percpu(fp->active);
286  	vfree(fp);
287  }
288  
bpf_prog_calc_tag(struct bpf_prog * fp)289  int bpf_prog_calc_tag(struct bpf_prog *fp)
290  {
291  	const u32 bits_offset = SHA1_BLOCK_SIZE - sizeof(__be64);
292  	u32 raw_size = bpf_prog_tag_scratch_size(fp);
293  	u32 digest[SHA1_DIGEST_WORDS];
294  	u32 ws[SHA1_WORKSPACE_WORDS];
295  	u32 i, bsize, psize, blocks;
296  	struct bpf_insn *dst;
297  	bool was_ld_map;
298  	u8 *raw, *todo;
299  	__be32 *result;
300  	__be64 *bits;
301  
302  	raw = vmalloc(raw_size);
303  	if (!raw)
304  		return -ENOMEM;
305  
306  	sha1_init(digest);
307  	memset(ws, 0, sizeof(ws));
308  
309  	/* We need to take out the map fd for the digest calculation
310  	 * since they are unstable from user space side.
311  	 */
312  	dst = (void *)raw;
313  	for (i = 0, was_ld_map = false; i < fp->len; i++) {
314  		dst[i] = fp->insnsi[i];
315  		if (!was_ld_map &&
316  		    dst[i].code == (BPF_LD | BPF_IMM | BPF_DW) &&
317  		    (dst[i].src_reg == BPF_PSEUDO_MAP_FD ||
318  		     dst[i].src_reg == BPF_PSEUDO_MAP_VALUE)) {
319  			was_ld_map = true;
320  			dst[i].imm = 0;
321  		} else if (was_ld_map &&
322  			   dst[i].code == 0 &&
323  			   dst[i].dst_reg == 0 &&
324  			   dst[i].src_reg == 0 &&
325  			   dst[i].off == 0) {
326  			was_ld_map = false;
327  			dst[i].imm = 0;
328  		} else {
329  			was_ld_map = false;
330  		}
331  	}
332  
333  	psize = bpf_prog_insn_size(fp);
334  	memset(&raw[psize], 0, raw_size - psize);
335  	raw[psize++] = 0x80;
336  
337  	bsize  = round_up(psize, SHA1_BLOCK_SIZE);
338  	blocks = bsize / SHA1_BLOCK_SIZE;
339  	todo   = raw;
340  	if (bsize - psize >= sizeof(__be64)) {
341  		bits = (__be64 *)(todo + bsize - sizeof(__be64));
342  	} else {
343  		bits = (__be64 *)(todo + bsize + bits_offset);
344  		blocks++;
345  	}
346  	*bits = cpu_to_be64((psize - 1) << 3);
347  
348  	while (blocks--) {
349  		sha1_transform(digest, todo, ws);
350  		todo += SHA1_BLOCK_SIZE;
351  	}
352  
353  	result = (__force __be32 *)digest;
354  	for (i = 0; i < SHA1_DIGEST_WORDS; i++)
355  		result[i] = cpu_to_be32(digest[i]);
356  	memcpy(fp->tag, result, sizeof(fp->tag));
357  
358  	vfree(raw);
359  	return 0;
360  }
361  
bpf_adj_delta_to_imm(struct bpf_insn * insn,u32 pos,s32 end_old,s32 end_new,s32 curr,const bool probe_pass)362  static int bpf_adj_delta_to_imm(struct bpf_insn *insn, u32 pos, s32 end_old,
363  				s32 end_new, s32 curr, const bool probe_pass)
364  {
365  	const s64 imm_min = S32_MIN, imm_max = S32_MAX;
366  	s32 delta = end_new - end_old;
367  	s64 imm = insn->imm;
368  
369  	if (curr < pos && curr + imm + 1 >= end_old)
370  		imm += delta;
371  	else if (curr >= end_new && curr + imm + 1 < end_new)
372  		imm -= delta;
373  	if (imm < imm_min || imm > imm_max)
374  		return -ERANGE;
375  	if (!probe_pass)
376  		insn->imm = imm;
377  	return 0;
378  }
379  
bpf_adj_delta_to_off(struct bpf_insn * insn,u32 pos,s32 end_old,s32 end_new,s32 curr,const bool probe_pass)380  static int bpf_adj_delta_to_off(struct bpf_insn *insn, u32 pos, s32 end_old,
381  				s32 end_new, s32 curr, const bool probe_pass)
382  {
383  	s64 off_min, off_max, off;
384  	s32 delta = end_new - end_old;
385  
386  	if (insn->code == (BPF_JMP32 | BPF_JA)) {
387  		off = insn->imm;
388  		off_min = S32_MIN;
389  		off_max = S32_MAX;
390  	} else {
391  		off = insn->off;
392  		off_min = S16_MIN;
393  		off_max = S16_MAX;
394  	}
395  
396  	if (curr < pos && curr + off + 1 >= end_old)
397  		off += delta;
398  	else if (curr >= end_new && curr + off + 1 < end_new)
399  		off -= delta;
400  	if (off < off_min || off > off_max)
401  		return -ERANGE;
402  	if (!probe_pass) {
403  		if (insn->code == (BPF_JMP32 | BPF_JA))
404  			insn->imm = off;
405  		else
406  			insn->off = off;
407  	}
408  	return 0;
409  }
410  
bpf_adj_branches(struct bpf_prog * prog,u32 pos,s32 end_old,s32 end_new,const bool probe_pass)411  static int bpf_adj_branches(struct bpf_prog *prog, u32 pos, s32 end_old,
412  			    s32 end_new, const bool probe_pass)
413  {
414  	u32 i, insn_cnt = prog->len + (probe_pass ? end_new - end_old : 0);
415  	struct bpf_insn *insn = prog->insnsi;
416  	int ret = 0;
417  
418  	for (i = 0; i < insn_cnt; i++, insn++) {
419  		u8 code;
420  
421  		/* In the probing pass we still operate on the original,
422  		 * unpatched image in order to check overflows before we
423  		 * do any other adjustments. Therefore skip the patchlet.
424  		 */
425  		if (probe_pass && i == pos) {
426  			i = end_new;
427  			insn = prog->insnsi + end_old;
428  		}
429  		if (bpf_pseudo_func(insn)) {
430  			ret = bpf_adj_delta_to_imm(insn, pos, end_old,
431  						   end_new, i, probe_pass);
432  			if (ret)
433  				return ret;
434  			continue;
435  		}
436  		code = insn->code;
437  		if ((BPF_CLASS(code) != BPF_JMP &&
438  		     BPF_CLASS(code) != BPF_JMP32) ||
439  		    BPF_OP(code) == BPF_EXIT)
440  			continue;
441  		/* Adjust offset of jmps if we cross patch boundaries. */
442  		if (BPF_OP(code) == BPF_CALL) {
443  			if (insn->src_reg != BPF_PSEUDO_CALL)
444  				continue;
445  			ret = bpf_adj_delta_to_imm(insn, pos, end_old,
446  						   end_new, i, probe_pass);
447  		} else {
448  			ret = bpf_adj_delta_to_off(insn, pos, end_old,
449  						   end_new, i, probe_pass);
450  		}
451  		if (ret)
452  			break;
453  	}
454  
455  	return ret;
456  }
457  
bpf_adj_linfo(struct bpf_prog * prog,u32 off,u32 delta)458  static void bpf_adj_linfo(struct bpf_prog *prog, u32 off, u32 delta)
459  {
460  	struct bpf_line_info *linfo;
461  	u32 i, nr_linfo;
462  
463  	nr_linfo = prog->aux->nr_linfo;
464  	if (!nr_linfo || !delta)
465  		return;
466  
467  	linfo = prog->aux->linfo;
468  
469  	for (i = 0; i < nr_linfo; i++)
470  		if (off < linfo[i].insn_off)
471  			break;
472  
473  	/* Push all off < linfo[i].insn_off by delta */
474  	for (; i < nr_linfo; i++)
475  		linfo[i].insn_off += delta;
476  }
477  
bpf_patch_insn_single(struct bpf_prog * prog,u32 off,const struct bpf_insn * patch,u32 len)478  struct bpf_prog *bpf_patch_insn_single(struct bpf_prog *prog, u32 off,
479  				       const struct bpf_insn *patch, u32 len)
480  {
481  	u32 insn_adj_cnt, insn_rest, insn_delta = len - 1;
482  	const u32 cnt_max = S16_MAX;
483  	struct bpf_prog *prog_adj;
484  	int err;
485  
486  	/* Since our patchlet doesn't expand the image, we're done. */
487  	if (insn_delta == 0) {
488  		memcpy(prog->insnsi + off, patch, sizeof(*patch));
489  		return prog;
490  	}
491  
492  	insn_adj_cnt = prog->len + insn_delta;
493  
494  	/* Reject anything that would potentially let the insn->off
495  	 * target overflow when we have excessive program expansions.
496  	 * We need to probe here before we do any reallocation where
497  	 * we afterwards may not fail anymore.
498  	 */
499  	if (insn_adj_cnt > cnt_max &&
500  	    (err = bpf_adj_branches(prog, off, off + 1, off + len, true)))
501  		return ERR_PTR(err);
502  
503  	/* Several new instructions need to be inserted. Make room
504  	 * for them. Likely, there's no need for a new allocation as
505  	 * last page could have large enough tailroom.
506  	 */
507  	prog_adj = bpf_prog_realloc(prog, bpf_prog_size(insn_adj_cnt),
508  				    GFP_USER);
509  	if (!prog_adj)
510  		return ERR_PTR(-ENOMEM);
511  
512  	prog_adj->len = insn_adj_cnt;
513  
514  	/* Patching happens in 3 steps:
515  	 *
516  	 * 1) Move over tail of insnsi from next instruction onwards,
517  	 *    so we can patch the single target insn with one or more
518  	 *    new ones (patching is always from 1 to n insns, n > 0).
519  	 * 2) Inject new instructions at the target location.
520  	 * 3) Adjust branch offsets if necessary.
521  	 */
522  	insn_rest = insn_adj_cnt - off - len;
523  
524  	memmove(prog_adj->insnsi + off + len, prog_adj->insnsi + off + 1,
525  		sizeof(*patch) * insn_rest);
526  	memcpy(prog_adj->insnsi + off, patch, sizeof(*patch) * len);
527  
528  	/* We are guaranteed to not fail at this point, otherwise
529  	 * the ship has sailed to reverse to the original state. An
530  	 * overflow cannot happen at this point.
531  	 */
532  	BUG_ON(bpf_adj_branches(prog_adj, off, off + 1, off + len, false));
533  
534  	bpf_adj_linfo(prog_adj, off, insn_delta);
535  
536  	return prog_adj;
537  }
538  
bpf_remove_insns(struct bpf_prog * prog,u32 off,u32 cnt)539  int bpf_remove_insns(struct bpf_prog *prog, u32 off, u32 cnt)
540  {
541  	/* Branch offsets can't overflow when program is shrinking, no need
542  	 * to call bpf_adj_branches(..., true) here
543  	 */
544  	memmove(prog->insnsi + off, prog->insnsi + off + cnt,
545  		sizeof(struct bpf_insn) * (prog->len - off - cnt));
546  	prog->len -= cnt;
547  
548  	return WARN_ON_ONCE(bpf_adj_branches(prog, off, off + cnt, off, false));
549  }
550  
bpf_prog_kallsyms_del_subprogs(struct bpf_prog * fp)551  static void bpf_prog_kallsyms_del_subprogs(struct bpf_prog *fp)
552  {
553  	int i;
554  
555  	for (i = 0; i < fp->aux->real_func_cnt; i++)
556  		bpf_prog_kallsyms_del(fp->aux->func[i]);
557  }
558  
bpf_prog_kallsyms_del_all(struct bpf_prog * fp)559  void bpf_prog_kallsyms_del_all(struct bpf_prog *fp)
560  {
561  	bpf_prog_kallsyms_del_subprogs(fp);
562  	bpf_prog_kallsyms_del(fp);
563  }
564  
565  #ifdef CONFIG_BPF_JIT
566  /* All BPF JIT sysctl knobs here. */
567  int bpf_jit_enable   __read_mostly = IS_BUILTIN(CONFIG_BPF_JIT_DEFAULT_ON);
568  int bpf_jit_kallsyms __read_mostly = IS_BUILTIN(CONFIG_BPF_JIT_DEFAULT_ON);
569  int bpf_jit_harden   __read_mostly;
570  long bpf_jit_limit   __read_mostly;
571  long bpf_jit_limit_max __read_mostly;
572  
573  static void
bpf_prog_ksym_set_addr(struct bpf_prog * prog)574  bpf_prog_ksym_set_addr(struct bpf_prog *prog)
575  {
576  	WARN_ON_ONCE(!bpf_prog_ebpf_jited(prog));
577  
578  	prog->aux->ksym.start = (unsigned long) prog->bpf_func;
579  	prog->aux->ksym.end   = prog->aux->ksym.start + prog->jited_len;
580  }
581  
582  static void
bpf_prog_ksym_set_name(struct bpf_prog * prog)583  bpf_prog_ksym_set_name(struct bpf_prog *prog)
584  {
585  	char *sym = prog->aux->ksym.name;
586  	const char *end = sym + KSYM_NAME_LEN;
587  	const struct btf_type *type;
588  	const char *func_name;
589  
590  	BUILD_BUG_ON(sizeof("bpf_prog_") +
591  		     sizeof(prog->tag) * 2 +
592  		     /* name has been null terminated.
593  		      * We should need +1 for the '_' preceding
594  		      * the name.  However, the null character
595  		      * is double counted between the name and the
596  		      * sizeof("bpf_prog_") above, so we omit
597  		      * the +1 here.
598  		      */
599  		     sizeof(prog->aux->name) > KSYM_NAME_LEN);
600  
601  	sym += snprintf(sym, KSYM_NAME_LEN, "bpf_prog_");
602  	sym  = bin2hex(sym, prog->tag, sizeof(prog->tag));
603  
604  	/* prog->aux->name will be ignored if full btf name is available */
605  	if (prog->aux->func_info_cnt && prog->aux->func_idx < prog->aux->func_info_cnt) {
606  		type = btf_type_by_id(prog->aux->btf,
607  				      prog->aux->func_info[prog->aux->func_idx].type_id);
608  		func_name = btf_name_by_offset(prog->aux->btf, type->name_off);
609  		snprintf(sym, (size_t)(end - sym), "_%s", func_name);
610  		return;
611  	}
612  
613  	if (prog->aux->name[0])
614  		snprintf(sym, (size_t)(end - sym), "_%s", prog->aux->name);
615  	else
616  		*sym = 0;
617  }
618  
bpf_get_ksym_start(struct latch_tree_node * n)619  static unsigned long bpf_get_ksym_start(struct latch_tree_node *n)
620  {
621  	return container_of(n, struct bpf_ksym, tnode)->start;
622  }
623  
bpf_tree_less(struct latch_tree_node * a,struct latch_tree_node * b)624  static __always_inline bool bpf_tree_less(struct latch_tree_node *a,
625  					  struct latch_tree_node *b)
626  {
627  	return bpf_get_ksym_start(a) < bpf_get_ksym_start(b);
628  }
629  
bpf_tree_comp(void * key,struct latch_tree_node * n)630  static __always_inline int bpf_tree_comp(void *key, struct latch_tree_node *n)
631  {
632  	unsigned long val = (unsigned long)key;
633  	const struct bpf_ksym *ksym;
634  
635  	ksym = container_of(n, struct bpf_ksym, tnode);
636  
637  	if (val < ksym->start)
638  		return -1;
639  	/* Ensure that we detect return addresses as part of the program, when
640  	 * the final instruction is a call for a program part of the stack
641  	 * trace. Therefore, do val > ksym->end instead of val >= ksym->end.
642  	 */
643  	if (val > ksym->end)
644  		return  1;
645  
646  	return 0;
647  }
648  
649  static const struct latch_tree_ops bpf_tree_ops = {
650  	.less	= bpf_tree_less,
651  	.comp	= bpf_tree_comp,
652  };
653  
654  static DEFINE_SPINLOCK(bpf_lock);
655  static LIST_HEAD(bpf_kallsyms);
656  static struct latch_tree_root bpf_tree __cacheline_aligned;
657  
bpf_ksym_add(struct bpf_ksym * ksym)658  void bpf_ksym_add(struct bpf_ksym *ksym)
659  {
660  	spin_lock_bh(&bpf_lock);
661  	WARN_ON_ONCE(!list_empty(&ksym->lnode));
662  	list_add_tail_rcu(&ksym->lnode, &bpf_kallsyms);
663  	latch_tree_insert(&ksym->tnode, &bpf_tree, &bpf_tree_ops);
664  	spin_unlock_bh(&bpf_lock);
665  }
666  
__bpf_ksym_del(struct bpf_ksym * ksym)667  static void __bpf_ksym_del(struct bpf_ksym *ksym)
668  {
669  	if (list_empty(&ksym->lnode))
670  		return;
671  
672  	latch_tree_erase(&ksym->tnode, &bpf_tree, &bpf_tree_ops);
673  	list_del_rcu(&ksym->lnode);
674  }
675  
bpf_ksym_del(struct bpf_ksym * ksym)676  void bpf_ksym_del(struct bpf_ksym *ksym)
677  {
678  	spin_lock_bh(&bpf_lock);
679  	__bpf_ksym_del(ksym);
680  	spin_unlock_bh(&bpf_lock);
681  }
682  
bpf_prog_kallsyms_candidate(const struct bpf_prog * fp)683  static bool bpf_prog_kallsyms_candidate(const struct bpf_prog *fp)
684  {
685  	return fp->jited && !bpf_prog_was_classic(fp);
686  }
687  
bpf_prog_kallsyms_add(struct bpf_prog * fp)688  void bpf_prog_kallsyms_add(struct bpf_prog *fp)
689  {
690  	if (!bpf_prog_kallsyms_candidate(fp) ||
691  	    !bpf_token_capable(fp->aux->token, CAP_BPF))
692  		return;
693  
694  	bpf_prog_ksym_set_addr(fp);
695  	bpf_prog_ksym_set_name(fp);
696  	fp->aux->ksym.prog = true;
697  
698  	bpf_ksym_add(&fp->aux->ksym);
699  
700  #ifdef CONFIG_FINEIBT
701  	/*
702  	 * When FineIBT, code in the __cfi_foo() symbols can get executed
703  	 * and hence unwinder needs help.
704  	 */
705  	if (cfi_mode != CFI_FINEIBT)
706  		return;
707  
708  	snprintf(fp->aux->ksym_prefix.name, KSYM_NAME_LEN,
709  		 "__cfi_%s", fp->aux->ksym.name);
710  
711  	fp->aux->ksym_prefix.start = (unsigned long) fp->bpf_func - 16;
712  	fp->aux->ksym_prefix.end   = (unsigned long) fp->bpf_func;
713  
714  	bpf_ksym_add(&fp->aux->ksym_prefix);
715  #endif
716  }
717  
bpf_prog_kallsyms_del(struct bpf_prog * fp)718  void bpf_prog_kallsyms_del(struct bpf_prog *fp)
719  {
720  	if (!bpf_prog_kallsyms_candidate(fp))
721  		return;
722  
723  	bpf_ksym_del(&fp->aux->ksym);
724  #ifdef CONFIG_FINEIBT
725  	if (cfi_mode != CFI_FINEIBT)
726  		return;
727  	bpf_ksym_del(&fp->aux->ksym_prefix);
728  #endif
729  }
730  
bpf_ksym_find(unsigned long addr)731  static struct bpf_ksym *bpf_ksym_find(unsigned long addr)
732  {
733  	struct latch_tree_node *n;
734  
735  	n = latch_tree_find((void *)addr, &bpf_tree, &bpf_tree_ops);
736  	return n ? container_of(n, struct bpf_ksym, tnode) : NULL;
737  }
738  
__bpf_address_lookup(unsigned long addr,unsigned long * size,unsigned long * off,char * sym)739  int __bpf_address_lookup(unsigned long addr, unsigned long *size,
740  				 unsigned long *off, char *sym)
741  {
742  	struct bpf_ksym *ksym;
743  	int ret = 0;
744  
745  	rcu_read_lock();
746  	ksym = bpf_ksym_find(addr);
747  	if (ksym) {
748  		unsigned long symbol_start = ksym->start;
749  		unsigned long symbol_end = ksym->end;
750  
751  		ret = strscpy(sym, ksym->name, KSYM_NAME_LEN);
752  
753  		if (size)
754  			*size = symbol_end - symbol_start;
755  		if (off)
756  			*off  = addr - symbol_start;
757  	}
758  	rcu_read_unlock();
759  
760  	return ret;
761  }
762  
is_bpf_text_address(unsigned long addr)763  bool is_bpf_text_address(unsigned long addr)
764  {
765  	bool ret;
766  
767  	rcu_read_lock();
768  	ret = bpf_ksym_find(addr) != NULL;
769  	rcu_read_unlock();
770  
771  	return ret;
772  }
773  
bpf_prog_ksym_find(unsigned long addr)774  struct bpf_prog *bpf_prog_ksym_find(unsigned long addr)
775  {
776  	struct bpf_ksym *ksym = bpf_ksym_find(addr);
777  
778  	return ksym && ksym->prog ?
779  	       container_of(ksym, struct bpf_prog_aux, ksym)->prog :
780  	       NULL;
781  }
782  
search_bpf_extables(unsigned long addr)783  const struct exception_table_entry *search_bpf_extables(unsigned long addr)
784  {
785  	const struct exception_table_entry *e = NULL;
786  	struct bpf_prog *prog;
787  
788  	rcu_read_lock();
789  	prog = bpf_prog_ksym_find(addr);
790  	if (!prog)
791  		goto out;
792  	if (!prog->aux->num_exentries)
793  		goto out;
794  
795  	e = search_extable(prog->aux->extable, prog->aux->num_exentries, addr);
796  out:
797  	rcu_read_unlock();
798  	return e;
799  }
800  
bpf_get_kallsym(unsigned int symnum,unsigned long * value,char * type,char * sym)801  int bpf_get_kallsym(unsigned int symnum, unsigned long *value, char *type,
802  		    char *sym)
803  {
804  	struct bpf_ksym *ksym;
805  	unsigned int it = 0;
806  	int ret = -ERANGE;
807  
808  	if (!bpf_jit_kallsyms_enabled())
809  		return ret;
810  
811  	rcu_read_lock();
812  	list_for_each_entry_rcu(ksym, &bpf_kallsyms, lnode) {
813  		if (it++ != symnum)
814  			continue;
815  
816  		strscpy(sym, ksym->name, KSYM_NAME_LEN);
817  
818  		*value = ksym->start;
819  		*type  = BPF_SYM_ELF_TYPE;
820  
821  		ret = 0;
822  		break;
823  	}
824  	rcu_read_unlock();
825  
826  	return ret;
827  }
828  
bpf_jit_add_poke_descriptor(struct bpf_prog * prog,struct bpf_jit_poke_descriptor * poke)829  int bpf_jit_add_poke_descriptor(struct bpf_prog *prog,
830  				struct bpf_jit_poke_descriptor *poke)
831  {
832  	struct bpf_jit_poke_descriptor *tab = prog->aux->poke_tab;
833  	static const u32 poke_tab_max = 1024;
834  	u32 slot = prog->aux->size_poke_tab;
835  	u32 size = slot + 1;
836  
837  	if (size > poke_tab_max)
838  		return -ENOSPC;
839  	if (poke->tailcall_target || poke->tailcall_target_stable ||
840  	    poke->tailcall_bypass || poke->adj_off || poke->bypass_addr)
841  		return -EINVAL;
842  
843  	switch (poke->reason) {
844  	case BPF_POKE_REASON_TAIL_CALL:
845  		if (!poke->tail_call.map)
846  			return -EINVAL;
847  		break;
848  	default:
849  		return -EINVAL;
850  	}
851  
852  	tab = krealloc_array(tab, size, sizeof(*poke), GFP_KERNEL);
853  	if (!tab)
854  		return -ENOMEM;
855  
856  	memcpy(&tab[slot], poke, sizeof(*poke));
857  	prog->aux->size_poke_tab = size;
858  	prog->aux->poke_tab = tab;
859  
860  	return slot;
861  }
862  
863  /*
864   * BPF program pack allocator.
865   *
866   * Most BPF programs are pretty small. Allocating a hole page for each
867   * program is sometime a waste. Many small bpf program also adds pressure
868   * to instruction TLB. To solve this issue, we introduce a BPF program pack
869   * allocator. The prog_pack allocator uses HPAGE_PMD_SIZE page (2MB on x86)
870   * to host BPF programs.
871   */
872  #define BPF_PROG_CHUNK_SHIFT	6
873  #define BPF_PROG_CHUNK_SIZE	(1 << BPF_PROG_CHUNK_SHIFT)
874  #define BPF_PROG_CHUNK_MASK	(~(BPF_PROG_CHUNK_SIZE - 1))
875  
876  struct bpf_prog_pack {
877  	struct list_head list;
878  	void *ptr;
879  	unsigned long bitmap[];
880  };
881  
bpf_jit_fill_hole_with_zero(void * area,unsigned int size)882  void bpf_jit_fill_hole_with_zero(void *area, unsigned int size)
883  {
884  	memset(area, 0, size);
885  }
886  
887  #define BPF_PROG_SIZE_TO_NBITS(size)	(round_up(size, BPF_PROG_CHUNK_SIZE) / BPF_PROG_CHUNK_SIZE)
888  
889  static DEFINE_MUTEX(pack_mutex);
890  static LIST_HEAD(pack_list);
891  
892  /* PMD_SIZE is not available in some special config, e.g. ARCH=arm with
893   * CONFIG_MMU=n. Use PAGE_SIZE in these cases.
894   */
895  #ifdef PMD_SIZE
896  /* PMD_SIZE is really big for some archs. It doesn't make sense to
897   * reserve too much memory in one allocation. Hardcode BPF_PROG_PACK_SIZE to
898   * 2MiB * num_possible_nodes(). On most architectures PMD_SIZE will be
899   * greater than or equal to 2MB.
900   */
901  #define BPF_PROG_PACK_SIZE (SZ_2M * num_possible_nodes())
902  #else
903  #define BPF_PROG_PACK_SIZE PAGE_SIZE
904  #endif
905  
906  #define BPF_PROG_CHUNK_COUNT (BPF_PROG_PACK_SIZE / BPF_PROG_CHUNK_SIZE)
907  
alloc_new_pack(bpf_jit_fill_hole_t bpf_fill_ill_insns)908  static struct bpf_prog_pack *alloc_new_pack(bpf_jit_fill_hole_t bpf_fill_ill_insns)
909  {
910  	struct bpf_prog_pack *pack;
911  	int err;
912  
913  	pack = kzalloc(struct_size(pack, bitmap, BITS_TO_LONGS(BPF_PROG_CHUNK_COUNT)),
914  		       GFP_KERNEL);
915  	if (!pack)
916  		return NULL;
917  	pack->ptr = bpf_jit_alloc_exec(BPF_PROG_PACK_SIZE);
918  	if (!pack->ptr)
919  		goto out;
920  	bpf_fill_ill_insns(pack->ptr, BPF_PROG_PACK_SIZE);
921  	bitmap_zero(pack->bitmap, BPF_PROG_PACK_SIZE / BPF_PROG_CHUNK_SIZE);
922  
923  	set_vm_flush_reset_perms(pack->ptr);
924  	err = set_memory_rox((unsigned long)pack->ptr,
925  			     BPF_PROG_PACK_SIZE / PAGE_SIZE);
926  	if (err)
927  		goto out;
928  	list_add_tail(&pack->list, &pack_list);
929  	return pack;
930  
931  out:
932  	bpf_jit_free_exec(pack->ptr);
933  	kfree(pack);
934  	return NULL;
935  }
936  
bpf_prog_pack_alloc(u32 size,bpf_jit_fill_hole_t bpf_fill_ill_insns)937  void *bpf_prog_pack_alloc(u32 size, bpf_jit_fill_hole_t bpf_fill_ill_insns)
938  {
939  	unsigned int nbits = BPF_PROG_SIZE_TO_NBITS(size);
940  	struct bpf_prog_pack *pack;
941  	unsigned long pos;
942  	void *ptr = NULL;
943  
944  	mutex_lock(&pack_mutex);
945  	if (size > BPF_PROG_PACK_SIZE) {
946  		size = round_up(size, PAGE_SIZE);
947  		ptr = bpf_jit_alloc_exec(size);
948  		if (ptr) {
949  			int err;
950  
951  			bpf_fill_ill_insns(ptr, size);
952  			set_vm_flush_reset_perms(ptr);
953  			err = set_memory_rox((unsigned long)ptr,
954  					     size / PAGE_SIZE);
955  			if (err) {
956  				bpf_jit_free_exec(ptr);
957  				ptr = NULL;
958  			}
959  		}
960  		goto out;
961  	}
962  	list_for_each_entry(pack, &pack_list, list) {
963  		pos = bitmap_find_next_zero_area(pack->bitmap, BPF_PROG_CHUNK_COUNT, 0,
964  						 nbits, 0);
965  		if (pos < BPF_PROG_CHUNK_COUNT)
966  			goto found_free_area;
967  	}
968  
969  	pack = alloc_new_pack(bpf_fill_ill_insns);
970  	if (!pack)
971  		goto out;
972  
973  	pos = 0;
974  
975  found_free_area:
976  	bitmap_set(pack->bitmap, pos, nbits);
977  	ptr = (void *)(pack->ptr) + (pos << BPF_PROG_CHUNK_SHIFT);
978  
979  out:
980  	mutex_unlock(&pack_mutex);
981  	return ptr;
982  }
983  
bpf_prog_pack_free(void * ptr,u32 size)984  void bpf_prog_pack_free(void *ptr, u32 size)
985  {
986  	struct bpf_prog_pack *pack = NULL, *tmp;
987  	unsigned int nbits;
988  	unsigned long pos;
989  
990  	mutex_lock(&pack_mutex);
991  	if (size > BPF_PROG_PACK_SIZE) {
992  		bpf_jit_free_exec(ptr);
993  		goto out;
994  	}
995  
996  	list_for_each_entry(tmp, &pack_list, list) {
997  		if (ptr >= tmp->ptr && (tmp->ptr + BPF_PROG_PACK_SIZE) > ptr) {
998  			pack = tmp;
999  			break;
1000  		}
1001  	}
1002  
1003  	if (WARN_ONCE(!pack, "bpf_prog_pack bug\n"))
1004  		goto out;
1005  
1006  	nbits = BPF_PROG_SIZE_TO_NBITS(size);
1007  	pos = ((unsigned long)ptr - (unsigned long)pack->ptr) >> BPF_PROG_CHUNK_SHIFT;
1008  
1009  	WARN_ONCE(bpf_arch_text_invalidate(ptr, size),
1010  		  "bpf_prog_pack bug: missing bpf_arch_text_invalidate?\n");
1011  
1012  	bitmap_clear(pack->bitmap, pos, nbits);
1013  	if (bitmap_find_next_zero_area(pack->bitmap, BPF_PROG_CHUNK_COUNT, 0,
1014  				       BPF_PROG_CHUNK_COUNT, 0) == 0) {
1015  		list_del(&pack->list);
1016  		bpf_jit_free_exec(pack->ptr);
1017  		kfree(pack);
1018  	}
1019  out:
1020  	mutex_unlock(&pack_mutex);
1021  }
1022  
1023  static atomic_long_t bpf_jit_current;
1024  
1025  /* Can be overridden by an arch's JIT compiler if it has a custom,
1026   * dedicated BPF backend memory area, or if neither of the two
1027   * below apply.
1028   */
bpf_jit_alloc_exec_limit(void)1029  u64 __weak bpf_jit_alloc_exec_limit(void)
1030  {
1031  #if defined(MODULES_VADDR)
1032  	return MODULES_END - MODULES_VADDR;
1033  #else
1034  	return VMALLOC_END - VMALLOC_START;
1035  #endif
1036  }
1037  
bpf_jit_charge_init(void)1038  static int __init bpf_jit_charge_init(void)
1039  {
1040  	/* Only used as heuristic here to derive limit. */
1041  	bpf_jit_limit_max = bpf_jit_alloc_exec_limit();
1042  	bpf_jit_limit = min_t(u64, round_up(bpf_jit_limit_max >> 1,
1043  					    PAGE_SIZE), LONG_MAX);
1044  	return 0;
1045  }
1046  pure_initcall(bpf_jit_charge_init);
1047  
bpf_jit_charge_modmem(u32 size)1048  int bpf_jit_charge_modmem(u32 size)
1049  {
1050  	if (atomic_long_add_return(size, &bpf_jit_current) > READ_ONCE(bpf_jit_limit)) {
1051  		if (!bpf_capable()) {
1052  			atomic_long_sub(size, &bpf_jit_current);
1053  			return -EPERM;
1054  		}
1055  	}
1056  
1057  	return 0;
1058  }
1059  
bpf_jit_uncharge_modmem(u32 size)1060  void bpf_jit_uncharge_modmem(u32 size)
1061  {
1062  	atomic_long_sub(size, &bpf_jit_current);
1063  }
1064  
bpf_jit_alloc_exec(unsigned long size)1065  void *__weak bpf_jit_alloc_exec(unsigned long size)
1066  {
1067  	return execmem_alloc(EXECMEM_BPF, size);
1068  }
1069  
bpf_jit_free_exec(void * addr)1070  void __weak bpf_jit_free_exec(void *addr)
1071  {
1072  	execmem_free(addr);
1073  }
1074  
1075  struct bpf_binary_header *
bpf_jit_binary_alloc(unsigned int proglen,u8 ** image_ptr,unsigned int alignment,bpf_jit_fill_hole_t bpf_fill_ill_insns)1076  bpf_jit_binary_alloc(unsigned int proglen, u8 **image_ptr,
1077  		     unsigned int alignment,
1078  		     bpf_jit_fill_hole_t bpf_fill_ill_insns)
1079  {
1080  	struct bpf_binary_header *hdr;
1081  	u32 size, hole, start;
1082  
1083  	WARN_ON_ONCE(!is_power_of_2(alignment) ||
1084  		     alignment > BPF_IMAGE_ALIGNMENT);
1085  
1086  	/* Most of BPF filters are really small, but if some of them
1087  	 * fill a page, allow at least 128 extra bytes to insert a
1088  	 * random section of illegal instructions.
1089  	 */
1090  	size = round_up(proglen + sizeof(*hdr) + 128, PAGE_SIZE);
1091  
1092  	if (bpf_jit_charge_modmem(size))
1093  		return NULL;
1094  	hdr = bpf_jit_alloc_exec(size);
1095  	if (!hdr) {
1096  		bpf_jit_uncharge_modmem(size);
1097  		return NULL;
1098  	}
1099  
1100  	/* Fill space with illegal/arch-dep instructions. */
1101  	bpf_fill_ill_insns(hdr, size);
1102  
1103  	hdr->size = size;
1104  	hole = min_t(unsigned int, size - (proglen + sizeof(*hdr)),
1105  		     PAGE_SIZE - sizeof(*hdr));
1106  	start = get_random_u32_below(hole) & ~(alignment - 1);
1107  
1108  	/* Leave a random number of instructions before BPF code. */
1109  	*image_ptr = &hdr->image[start];
1110  
1111  	return hdr;
1112  }
1113  
bpf_jit_binary_free(struct bpf_binary_header * hdr)1114  void bpf_jit_binary_free(struct bpf_binary_header *hdr)
1115  {
1116  	u32 size = hdr->size;
1117  
1118  	bpf_jit_free_exec(hdr);
1119  	bpf_jit_uncharge_modmem(size);
1120  }
1121  
1122  /* Allocate jit binary from bpf_prog_pack allocator.
1123   * Since the allocated memory is RO+X, the JIT engine cannot write directly
1124   * to the memory. To solve this problem, a RW buffer is also allocated at
1125   * as the same time. The JIT engine should calculate offsets based on the
1126   * RO memory address, but write JITed program to the RW buffer. Once the
1127   * JIT engine finishes, it calls bpf_jit_binary_pack_finalize, which copies
1128   * the JITed program to the RO memory.
1129   */
1130  struct bpf_binary_header *
bpf_jit_binary_pack_alloc(unsigned int proglen,u8 ** image_ptr,unsigned int alignment,struct bpf_binary_header ** rw_header,u8 ** rw_image,bpf_jit_fill_hole_t bpf_fill_ill_insns)1131  bpf_jit_binary_pack_alloc(unsigned int proglen, u8 **image_ptr,
1132  			  unsigned int alignment,
1133  			  struct bpf_binary_header **rw_header,
1134  			  u8 **rw_image,
1135  			  bpf_jit_fill_hole_t bpf_fill_ill_insns)
1136  {
1137  	struct bpf_binary_header *ro_header;
1138  	u32 size, hole, start;
1139  
1140  	WARN_ON_ONCE(!is_power_of_2(alignment) ||
1141  		     alignment > BPF_IMAGE_ALIGNMENT);
1142  
1143  	/* add 16 bytes for a random section of illegal instructions */
1144  	size = round_up(proglen + sizeof(*ro_header) + 16, BPF_PROG_CHUNK_SIZE);
1145  
1146  	if (bpf_jit_charge_modmem(size))
1147  		return NULL;
1148  	ro_header = bpf_prog_pack_alloc(size, bpf_fill_ill_insns);
1149  	if (!ro_header) {
1150  		bpf_jit_uncharge_modmem(size);
1151  		return NULL;
1152  	}
1153  
1154  	*rw_header = kvmalloc(size, GFP_KERNEL);
1155  	if (!*rw_header) {
1156  		bpf_prog_pack_free(ro_header, size);
1157  		bpf_jit_uncharge_modmem(size);
1158  		return NULL;
1159  	}
1160  
1161  	/* Fill space with illegal/arch-dep instructions. */
1162  	bpf_fill_ill_insns(*rw_header, size);
1163  	(*rw_header)->size = size;
1164  
1165  	hole = min_t(unsigned int, size - (proglen + sizeof(*ro_header)),
1166  		     BPF_PROG_CHUNK_SIZE - sizeof(*ro_header));
1167  	start = get_random_u32_below(hole) & ~(alignment - 1);
1168  
1169  	*image_ptr = &ro_header->image[start];
1170  	*rw_image = &(*rw_header)->image[start];
1171  
1172  	return ro_header;
1173  }
1174  
1175  /* Copy JITed text from rw_header to its final location, the ro_header. */
bpf_jit_binary_pack_finalize(struct bpf_binary_header * ro_header,struct bpf_binary_header * rw_header)1176  int bpf_jit_binary_pack_finalize(struct bpf_binary_header *ro_header,
1177  				 struct bpf_binary_header *rw_header)
1178  {
1179  	void *ptr;
1180  
1181  	ptr = bpf_arch_text_copy(ro_header, rw_header, rw_header->size);
1182  
1183  	kvfree(rw_header);
1184  
1185  	if (IS_ERR(ptr)) {
1186  		bpf_prog_pack_free(ro_header, ro_header->size);
1187  		return PTR_ERR(ptr);
1188  	}
1189  	return 0;
1190  }
1191  
1192  /* bpf_jit_binary_pack_free is called in two different scenarios:
1193   *   1) when the program is freed after;
1194   *   2) when the JIT engine fails (before bpf_jit_binary_pack_finalize).
1195   * For case 2), we need to free both the RO memory and the RW buffer.
1196   *
1197   * bpf_jit_binary_pack_free requires proper ro_header->size. However,
1198   * bpf_jit_binary_pack_alloc does not set it. Therefore, ro_header->size
1199   * must be set with either bpf_jit_binary_pack_finalize (normal path) or
1200   * bpf_arch_text_copy (when jit fails).
1201   */
bpf_jit_binary_pack_free(struct bpf_binary_header * ro_header,struct bpf_binary_header * rw_header)1202  void bpf_jit_binary_pack_free(struct bpf_binary_header *ro_header,
1203  			      struct bpf_binary_header *rw_header)
1204  {
1205  	u32 size = ro_header->size;
1206  
1207  	bpf_prog_pack_free(ro_header, size);
1208  	kvfree(rw_header);
1209  	bpf_jit_uncharge_modmem(size);
1210  }
1211  
1212  struct bpf_binary_header *
bpf_jit_binary_pack_hdr(const struct bpf_prog * fp)1213  bpf_jit_binary_pack_hdr(const struct bpf_prog *fp)
1214  {
1215  	unsigned long real_start = (unsigned long)fp->bpf_func;
1216  	unsigned long addr;
1217  
1218  	addr = real_start & BPF_PROG_CHUNK_MASK;
1219  	return (void *)addr;
1220  }
1221  
1222  static inline struct bpf_binary_header *
bpf_jit_binary_hdr(const struct bpf_prog * fp)1223  bpf_jit_binary_hdr(const struct bpf_prog *fp)
1224  {
1225  	unsigned long real_start = (unsigned long)fp->bpf_func;
1226  	unsigned long addr;
1227  
1228  	addr = real_start & PAGE_MASK;
1229  	return (void *)addr;
1230  }
1231  
1232  /* This symbol is only overridden by archs that have different
1233   * requirements than the usual eBPF JITs, f.e. when they only
1234   * implement cBPF JIT, do not set images read-only, etc.
1235   */
bpf_jit_free(struct bpf_prog * fp)1236  void __weak bpf_jit_free(struct bpf_prog *fp)
1237  {
1238  	if (fp->jited) {
1239  		struct bpf_binary_header *hdr = bpf_jit_binary_hdr(fp);
1240  
1241  		bpf_jit_binary_free(hdr);
1242  		WARN_ON_ONCE(!bpf_prog_kallsyms_verify_off(fp));
1243  	}
1244  
1245  	bpf_prog_unlock_free(fp);
1246  }
1247  
bpf_jit_get_func_addr(const struct bpf_prog * prog,const struct bpf_insn * insn,bool extra_pass,u64 * func_addr,bool * func_addr_fixed)1248  int bpf_jit_get_func_addr(const struct bpf_prog *prog,
1249  			  const struct bpf_insn *insn, bool extra_pass,
1250  			  u64 *func_addr, bool *func_addr_fixed)
1251  {
1252  	s16 off = insn->off;
1253  	s32 imm = insn->imm;
1254  	u8 *addr;
1255  	int err;
1256  
1257  	*func_addr_fixed = insn->src_reg != BPF_PSEUDO_CALL;
1258  	if (!*func_addr_fixed) {
1259  		/* Place-holder address till the last pass has collected
1260  		 * all addresses for JITed subprograms in which case we
1261  		 * can pick them up from prog->aux.
1262  		 */
1263  		if (!extra_pass)
1264  			addr = NULL;
1265  		else if (prog->aux->func &&
1266  			 off >= 0 && off < prog->aux->real_func_cnt)
1267  			addr = (u8 *)prog->aux->func[off]->bpf_func;
1268  		else
1269  			return -EINVAL;
1270  	} else if (insn->src_reg == BPF_PSEUDO_KFUNC_CALL &&
1271  		   bpf_jit_supports_far_kfunc_call()) {
1272  		err = bpf_get_kfunc_addr(prog, insn->imm, insn->off, &addr);
1273  		if (err)
1274  			return err;
1275  	} else {
1276  		/* Address of a BPF helper call. Since part of the core
1277  		 * kernel, it's always at a fixed location. __bpf_call_base
1278  		 * and the helper with imm relative to it are both in core
1279  		 * kernel.
1280  		 */
1281  		addr = (u8 *)__bpf_call_base + imm;
1282  	}
1283  
1284  	*func_addr = (unsigned long)addr;
1285  	return 0;
1286  }
1287  
bpf_jit_blind_insn(const struct bpf_insn * from,const struct bpf_insn * aux,struct bpf_insn * to_buff,bool emit_zext)1288  static int bpf_jit_blind_insn(const struct bpf_insn *from,
1289  			      const struct bpf_insn *aux,
1290  			      struct bpf_insn *to_buff,
1291  			      bool emit_zext)
1292  {
1293  	struct bpf_insn *to = to_buff;
1294  	u32 imm_rnd = get_random_u32();
1295  	s16 off;
1296  
1297  	BUILD_BUG_ON(BPF_REG_AX  + 1 != MAX_BPF_JIT_REG);
1298  	BUILD_BUG_ON(MAX_BPF_REG + 1 != MAX_BPF_JIT_REG);
1299  
1300  	/* Constraints on AX register:
1301  	 *
1302  	 * AX register is inaccessible from user space. It is mapped in
1303  	 * all JITs, and used here for constant blinding rewrites. It is
1304  	 * typically "stateless" meaning its contents are only valid within
1305  	 * the executed instruction, but not across several instructions.
1306  	 * There are a few exceptions however which are further detailed
1307  	 * below.
1308  	 *
1309  	 * Constant blinding is only used by JITs, not in the interpreter.
1310  	 * The interpreter uses AX in some occasions as a local temporary
1311  	 * register e.g. in DIV or MOD instructions.
1312  	 *
1313  	 * In restricted circumstances, the verifier can also use the AX
1314  	 * register for rewrites as long as they do not interfere with
1315  	 * the above cases!
1316  	 */
1317  	if (from->dst_reg == BPF_REG_AX || from->src_reg == BPF_REG_AX)
1318  		goto out;
1319  
1320  	if (from->imm == 0 &&
1321  	    (from->code == (BPF_ALU   | BPF_MOV | BPF_K) ||
1322  	     from->code == (BPF_ALU64 | BPF_MOV | BPF_K))) {
1323  		*to++ = BPF_ALU64_REG(BPF_XOR, from->dst_reg, from->dst_reg);
1324  		goto out;
1325  	}
1326  
1327  	switch (from->code) {
1328  	case BPF_ALU | BPF_ADD | BPF_K:
1329  	case BPF_ALU | BPF_SUB | BPF_K:
1330  	case BPF_ALU | BPF_AND | BPF_K:
1331  	case BPF_ALU | BPF_OR  | BPF_K:
1332  	case BPF_ALU | BPF_XOR | BPF_K:
1333  	case BPF_ALU | BPF_MUL | BPF_K:
1334  	case BPF_ALU | BPF_MOV | BPF_K:
1335  	case BPF_ALU | BPF_DIV | BPF_K:
1336  	case BPF_ALU | BPF_MOD | BPF_K:
1337  		*to++ = BPF_ALU32_IMM(BPF_MOV, BPF_REG_AX, imm_rnd ^ from->imm);
1338  		*to++ = BPF_ALU32_IMM(BPF_XOR, BPF_REG_AX, imm_rnd);
1339  		*to++ = BPF_ALU32_REG_OFF(from->code, from->dst_reg, BPF_REG_AX, from->off);
1340  		break;
1341  
1342  	case BPF_ALU64 | BPF_ADD | BPF_K:
1343  	case BPF_ALU64 | BPF_SUB | BPF_K:
1344  	case BPF_ALU64 | BPF_AND | BPF_K:
1345  	case BPF_ALU64 | BPF_OR  | BPF_K:
1346  	case BPF_ALU64 | BPF_XOR | BPF_K:
1347  	case BPF_ALU64 | BPF_MUL | BPF_K:
1348  	case BPF_ALU64 | BPF_MOV | BPF_K:
1349  	case BPF_ALU64 | BPF_DIV | BPF_K:
1350  	case BPF_ALU64 | BPF_MOD | BPF_K:
1351  		*to++ = BPF_ALU64_IMM(BPF_MOV, BPF_REG_AX, imm_rnd ^ from->imm);
1352  		*to++ = BPF_ALU64_IMM(BPF_XOR, BPF_REG_AX, imm_rnd);
1353  		*to++ = BPF_ALU64_REG_OFF(from->code, from->dst_reg, BPF_REG_AX, from->off);
1354  		break;
1355  
1356  	case BPF_JMP | BPF_JEQ  | BPF_K:
1357  	case BPF_JMP | BPF_JNE  | BPF_K:
1358  	case BPF_JMP | BPF_JGT  | BPF_K:
1359  	case BPF_JMP | BPF_JLT  | BPF_K:
1360  	case BPF_JMP | BPF_JGE  | BPF_K:
1361  	case BPF_JMP | BPF_JLE  | BPF_K:
1362  	case BPF_JMP | BPF_JSGT | BPF_K:
1363  	case BPF_JMP | BPF_JSLT | BPF_K:
1364  	case BPF_JMP | BPF_JSGE | BPF_K:
1365  	case BPF_JMP | BPF_JSLE | BPF_K:
1366  	case BPF_JMP | BPF_JSET | BPF_K:
1367  		/* Accommodate for extra offset in case of a backjump. */
1368  		off = from->off;
1369  		if (off < 0)
1370  			off -= 2;
1371  		*to++ = BPF_ALU64_IMM(BPF_MOV, BPF_REG_AX, imm_rnd ^ from->imm);
1372  		*to++ = BPF_ALU64_IMM(BPF_XOR, BPF_REG_AX, imm_rnd);
1373  		*to++ = BPF_JMP_REG(from->code, from->dst_reg, BPF_REG_AX, off);
1374  		break;
1375  
1376  	case BPF_JMP32 | BPF_JEQ  | BPF_K:
1377  	case BPF_JMP32 | BPF_JNE  | BPF_K:
1378  	case BPF_JMP32 | BPF_JGT  | BPF_K:
1379  	case BPF_JMP32 | BPF_JLT  | BPF_K:
1380  	case BPF_JMP32 | BPF_JGE  | BPF_K:
1381  	case BPF_JMP32 | BPF_JLE  | BPF_K:
1382  	case BPF_JMP32 | BPF_JSGT | BPF_K:
1383  	case BPF_JMP32 | BPF_JSLT | BPF_K:
1384  	case BPF_JMP32 | BPF_JSGE | BPF_K:
1385  	case BPF_JMP32 | BPF_JSLE | BPF_K:
1386  	case BPF_JMP32 | BPF_JSET | BPF_K:
1387  		/* Accommodate for extra offset in case of a backjump. */
1388  		off = from->off;
1389  		if (off < 0)
1390  			off -= 2;
1391  		*to++ = BPF_ALU32_IMM(BPF_MOV, BPF_REG_AX, imm_rnd ^ from->imm);
1392  		*to++ = BPF_ALU32_IMM(BPF_XOR, BPF_REG_AX, imm_rnd);
1393  		*to++ = BPF_JMP32_REG(from->code, from->dst_reg, BPF_REG_AX,
1394  				      off);
1395  		break;
1396  
1397  	case BPF_LD | BPF_IMM | BPF_DW:
1398  		*to++ = BPF_ALU64_IMM(BPF_MOV, BPF_REG_AX, imm_rnd ^ aux[1].imm);
1399  		*to++ = BPF_ALU64_IMM(BPF_XOR, BPF_REG_AX, imm_rnd);
1400  		*to++ = BPF_ALU64_IMM(BPF_LSH, BPF_REG_AX, 32);
1401  		*to++ = BPF_ALU64_REG(BPF_MOV, aux[0].dst_reg, BPF_REG_AX);
1402  		break;
1403  	case 0: /* Part 2 of BPF_LD | BPF_IMM | BPF_DW. */
1404  		*to++ = BPF_ALU32_IMM(BPF_MOV, BPF_REG_AX, imm_rnd ^ aux[0].imm);
1405  		*to++ = BPF_ALU32_IMM(BPF_XOR, BPF_REG_AX, imm_rnd);
1406  		if (emit_zext)
1407  			*to++ = BPF_ZEXT_REG(BPF_REG_AX);
1408  		*to++ = BPF_ALU64_REG(BPF_OR,  aux[0].dst_reg, BPF_REG_AX);
1409  		break;
1410  
1411  	case BPF_ST | BPF_MEM | BPF_DW:
1412  	case BPF_ST | BPF_MEM | BPF_W:
1413  	case BPF_ST | BPF_MEM | BPF_H:
1414  	case BPF_ST | BPF_MEM | BPF_B:
1415  		*to++ = BPF_ALU64_IMM(BPF_MOV, BPF_REG_AX, imm_rnd ^ from->imm);
1416  		*to++ = BPF_ALU64_IMM(BPF_XOR, BPF_REG_AX, imm_rnd);
1417  		*to++ = BPF_STX_MEM(from->code, from->dst_reg, BPF_REG_AX, from->off);
1418  		break;
1419  	}
1420  out:
1421  	return to - to_buff;
1422  }
1423  
bpf_prog_clone_create(struct bpf_prog * fp_other,gfp_t gfp_extra_flags)1424  static struct bpf_prog *bpf_prog_clone_create(struct bpf_prog *fp_other,
1425  					      gfp_t gfp_extra_flags)
1426  {
1427  	gfp_t gfp_flags = GFP_KERNEL | __GFP_ZERO | gfp_extra_flags;
1428  	struct bpf_prog *fp;
1429  
1430  	fp = __vmalloc(fp_other->pages * PAGE_SIZE, gfp_flags);
1431  	if (fp != NULL) {
1432  		/* aux->prog still points to the fp_other one, so
1433  		 * when promoting the clone to the real program,
1434  		 * this still needs to be adapted.
1435  		 */
1436  		memcpy(fp, fp_other, fp_other->pages * PAGE_SIZE);
1437  	}
1438  
1439  	return fp;
1440  }
1441  
bpf_prog_clone_free(struct bpf_prog * fp)1442  static void bpf_prog_clone_free(struct bpf_prog *fp)
1443  {
1444  	/* aux was stolen by the other clone, so we cannot free
1445  	 * it from this path! It will be freed eventually by the
1446  	 * other program on release.
1447  	 *
1448  	 * At this point, we don't need a deferred release since
1449  	 * clone is guaranteed to not be locked.
1450  	 */
1451  	fp->aux = NULL;
1452  	fp->stats = NULL;
1453  	fp->active = NULL;
1454  	__bpf_prog_free(fp);
1455  }
1456  
bpf_jit_prog_release_other(struct bpf_prog * fp,struct bpf_prog * fp_other)1457  void bpf_jit_prog_release_other(struct bpf_prog *fp, struct bpf_prog *fp_other)
1458  {
1459  	/* We have to repoint aux->prog to self, as we don't
1460  	 * know whether fp here is the clone or the original.
1461  	 */
1462  	fp->aux->prog = fp;
1463  	bpf_prog_clone_free(fp_other);
1464  }
1465  
bpf_jit_blind_constants(struct bpf_prog * prog)1466  struct bpf_prog *bpf_jit_blind_constants(struct bpf_prog *prog)
1467  {
1468  	struct bpf_insn insn_buff[16], aux[2];
1469  	struct bpf_prog *clone, *tmp;
1470  	int insn_delta, insn_cnt;
1471  	struct bpf_insn *insn;
1472  	int i, rewritten;
1473  
1474  	if (!prog->blinding_requested || prog->blinded)
1475  		return prog;
1476  
1477  	clone = bpf_prog_clone_create(prog, GFP_USER);
1478  	if (!clone)
1479  		return ERR_PTR(-ENOMEM);
1480  
1481  	insn_cnt = clone->len;
1482  	insn = clone->insnsi;
1483  
1484  	for (i = 0; i < insn_cnt; i++, insn++) {
1485  		if (bpf_pseudo_func(insn)) {
1486  			/* ld_imm64 with an address of bpf subprog is not
1487  			 * a user controlled constant. Don't randomize it,
1488  			 * since it will conflict with jit_subprogs() logic.
1489  			 */
1490  			insn++;
1491  			i++;
1492  			continue;
1493  		}
1494  
1495  		/* We temporarily need to hold the original ld64 insn
1496  		 * so that we can still access the first part in the
1497  		 * second blinding run.
1498  		 */
1499  		if (insn[0].code == (BPF_LD | BPF_IMM | BPF_DW) &&
1500  		    insn[1].code == 0)
1501  			memcpy(aux, insn, sizeof(aux));
1502  
1503  		rewritten = bpf_jit_blind_insn(insn, aux, insn_buff,
1504  						clone->aux->verifier_zext);
1505  		if (!rewritten)
1506  			continue;
1507  
1508  		tmp = bpf_patch_insn_single(clone, i, insn_buff, rewritten);
1509  		if (IS_ERR(tmp)) {
1510  			/* Patching may have repointed aux->prog during
1511  			 * realloc from the original one, so we need to
1512  			 * fix it up here on error.
1513  			 */
1514  			bpf_jit_prog_release_other(prog, clone);
1515  			return tmp;
1516  		}
1517  
1518  		clone = tmp;
1519  		insn_delta = rewritten - 1;
1520  
1521  		/* Walk new program and skip insns we just inserted. */
1522  		insn = clone->insnsi + i + insn_delta;
1523  		insn_cnt += insn_delta;
1524  		i        += insn_delta;
1525  	}
1526  
1527  	clone->blinded = 1;
1528  	return clone;
1529  }
1530  #endif /* CONFIG_BPF_JIT */
1531  
1532  /* Base function for offset calculation. Needs to go into .text section,
1533   * therefore keeping it non-static as well; will also be used by JITs
1534   * anyway later on, so do not let the compiler omit it. This also needs
1535   * to go into kallsyms for correlation from e.g. bpftool, so naming
1536   * must not change.
1537   */
__bpf_call_base(u64 r1,u64 r2,u64 r3,u64 r4,u64 r5)1538  noinline u64 __bpf_call_base(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5)
1539  {
1540  	return 0;
1541  }
1542  EXPORT_SYMBOL_GPL(__bpf_call_base);
1543  
1544  /* All UAPI available opcodes. */
1545  #define BPF_INSN_MAP(INSN_2, INSN_3)		\
1546  	/* 32 bit ALU operations. */		\
1547  	/*   Register based. */			\
1548  	INSN_3(ALU, ADD,  X),			\
1549  	INSN_3(ALU, SUB,  X),			\
1550  	INSN_3(ALU, AND,  X),			\
1551  	INSN_3(ALU, OR,   X),			\
1552  	INSN_3(ALU, LSH,  X),			\
1553  	INSN_3(ALU, RSH,  X),			\
1554  	INSN_3(ALU, XOR,  X),			\
1555  	INSN_3(ALU, MUL,  X),			\
1556  	INSN_3(ALU, MOV,  X),			\
1557  	INSN_3(ALU, ARSH, X),			\
1558  	INSN_3(ALU, DIV,  X),			\
1559  	INSN_3(ALU, MOD,  X),			\
1560  	INSN_2(ALU, NEG),			\
1561  	INSN_3(ALU, END, TO_BE),		\
1562  	INSN_3(ALU, END, TO_LE),		\
1563  	/*   Immediate based. */		\
1564  	INSN_3(ALU, ADD,  K),			\
1565  	INSN_3(ALU, SUB,  K),			\
1566  	INSN_3(ALU, AND,  K),			\
1567  	INSN_3(ALU, OR,   K),			\
1568  	INSN_3(ALU, LSH,  K),			\
1569  	INSN_3(ALU, RSH,  K),			\
1570  	INSN_3(ALU, XOR,  K),			\
1571  	INSN_3(ALU, MUL,  K),			\
1572  	INSN_3(ALU, MOV,  K),			\
1573  	INSN_3(ALU, ARSH, K),			\
1574  	INSN_3(ALU, DIV,  K),			\
1575  	INSN_3(ALU, MOD,  K),			\
1576  	/* 64 bit ALU operations. */		\
1577  	/*   Register based. */			\
1578  	INSN_3(ALU64, ADD,  X),			\
1579  	INSN_3(ALU64, SUB,  X),			\
1580  	INSN_3(ALU64, AND,  X),			\
1581  	INSN_3(ALU64, OR,   X),			\
1582  	INSN_3(ALU64, LSH,  X),			\
1583  	INSN_3(ALU64, RSH,  X),			\
1584  	INSN_3(ALU64, XOR,  X),			\
1585  	INSN_3(ALU64, MUL,  X),			\
1586  	INSN_3(ALU64, MOV,  X),			\
1587  	INSN_3(ALU64, ARSH, X),			\
1588  	INSN_3(ALU64, DIV,  X),			\
1589  	INSN_3(ALU64, MOD,  X),			\
1590  	INSN_2(ALU64, NEG),			\
1591  	INSN_3(ALU64, END, TO_LE),		\
1592  	/*   Immediate based. */		\
1593  	INSN_3(ALU64, ADD,  K),			\
1594  	INSN_3(ALU64, SUB,  K),			\
1595  	INSN_3(ALU64, AND,  K),			\
1596  	INSN_3(ALU64, OR,   K),			\
1597  	INSN_3(ALU64, LSH,  K),			\
1598  	INSN_3(ALU64, RSH,  K),			\
1599  	INSN_3(ALU64, XOR,  K),			\
1600  	INSN_3(ALU64, MUL,  K),			\
1601  	INSN_3(ALU64, MOV,  K),			\
1602  	INSN_3(ALU64, ARSH, K),			\
1603  	INSN_3(ALU64, DIV,  K),			\
1604  	INSN_3(ALU64, MOD,  K),			\
1605  	/* Call instruction. */			\
1606  	INSN_2(JMP, CALL),			\
1607  	/* Exit instruction. */			\
1608  	INSN_2(JMP, EXIT),			\
1609  	/* 32-bit Jump instructions. */		\
1610  	/*   Register based. */			\
1611  	INSN_3(JMP32, JEQ,  X),			\
1612  	INSN_3(JMP32, JNE,  X),			\
1613  	INSN_3(JMP32, JGT,  X),			\
1614  	INSN_3(JMP32, JLT,  X),			\
1615  	INSN_3(JMP32, JGE,  X),			\
1616  	INSN_3(JMP32, JLE,  X),			\
1617  	INSN_3(JMP32, JSGT, X),			\
1618  	INSN_3(JMP32, JSLT, X),			\
1619  	INSN_3(JMP32, JSGE, X),			\
1620  	INSN_3(JMP32, JSLE, X),			\
1621  	INSN_3(JMP32, JSET, X),			\
1622  	/*   Immediate based. */		\
1623  	INSN_3(JMP32, JEQ,  K),			\
1624  	INSN_3(JMP32, JNE,  K),			\
1625  	INSN_3(JMP32, JGT,  K),			\
1626  	INSN_3(JMP32, JLT,  K),			\
1627  	INSN_3(JMP32, JGE,  K),			\
1628  	INSN_3(JMP32, JLE,  K),			\
1629  	INSN_3(JMP32, JSGT, K),			\
1630  	INSN_3(JMP32, JSLT, K),			\
1631  	INSN_3(JMP32, JSGE, K),			\
1632  	INSN_3(JMP32, JSLE, K),			\
1633  	INSN_3(JMP32, JSET, K),			\
1634  	/* Jump instructions. */		\
1635  	/*   Register based. */			\
1636  	INSN_3(JMP, JEQ,  X),			\
1637  	INSN_3(JMP, JNE,  X),			\
1638  	INSN_3(JMP, JGT,  X),			\
1639  	INSN_3(JMP, JLT,  X),			\
1640  	INSN_3(JMP, JGE,  X),			\
1641  	INSN_3(JMP, JLE,  X),			\
1642  	INSN_3(JMP, JSGT, X),			\
1643  	INSN_3(JMP, JSLT, X),			\
1644  	INSN_3(JMP, JSGE, X),			\
1645  	INSN_3(JMP, JSLE, X),			\
1646  	INSN_3(JMP, JSET, X),			\
1647  	/*   Immediate based. */		\
1648  	INSN_3(JMP, JEQ,  K),			\
1649  	INSN_3(JMP, JNE,  K),			\
1650  	INSN_3(JMP, JGT,  K),			\
1651  	INSN_3(JMP, JLT,  K),			\
1652  	INSN_3(JMP, JGE,  K),			\
1653  	INSN_3(JMP, JLE,  K),			\
1654  	INSN_3(JMP, JSGT, K),			\
1655  	INSN_3(JMP, JSLT, K),			\
1656  	INSN_3(JMP, JSGE, K),			\
1657  	INSN_3(JMP, JSLE, K),			\
1658  	INSN_3(JMP, JSET, K),			\
1659  	INSN_2(JMP, JA),			\
1660  	INSN_2(JMP32, JA),			\
1661  	/* Store instructions. */		\
1662  	/*   Register based. */			\
1663  	INSN_3(STX, MEM,  B),			\
1664  	INSN_3(STX, MEM,  H),			\
1665  	INSN_3(STX, MEM,  W),			\
1666  	INSN_3(STX, MEM,  DW),			\
1667  	INSN_3(STX, ATOMIC, W),			\
1668  	INSN_3(STX, ATOMIC, DW),		\
1669  	/*   Immediate based. */		\
1670  	INSN_3(ST, MEM, B),			\
1671  	INSN_3(ST, MEM, H),			\
1672  	INSN_3(ST, MEM, W),			\
1673  	INSN_3(ST, MEM, DW),			\
1674  	/* Load instructions. */		\
1675  	/*   Register based. */			\
1676  	INSN_3(LDX, MEM, B),			\
1677  	INSN_3(LDX, MEM, H),			\
1678  	INSN_3(LDX, MEM, W),			\
1679  	INSN_3(LDX, MEM, DW),			\
1680  	INSN_3(LDX, MEMSX, B),			\
1681  	INSN_3(LDX, MEMSX, H),			\
1682  	INSN_3(LDX, MEMSX, W),			\
1683  	/*   Immediate based. */		\
1684  	INSN_3(LD, IMM, DW)
1685  
bpf_opcode_in_insntable(u8 code)1686  bool bpf_opcode_in_insntable(u8 code)
1687  {
1688  #define BPF_INSN_2_TBL(x, y)    [BPF_##x | BPF_##y] = true
1689  #define BPF_INSN_3_TBL(x, y, z) [BPF_##x | BPF_##y | BPF_##z] = true
1690  	static const bool public_insntable[256] = {
1691  		[0 ... 255] = false,
1692  		/* Now overwrite non-defaults ... */
1693  		BPF_INSN_MAP(BPF_INSN_2_TBL, BPF_INSN_3_TBL),
1694  		/* UAPI exposed, but rewritten opcodes. cBPF carry-over. */
1695  		[BPF_LD | BPF_ABS | BPF_B] = true,
1696  		[BPF_LD | BPF_ABS | BPF_H] = true,
1697  		[BPF_LD | BPF_ABS | BPF_W] = true,
1698  		[BPF_LD | BPF_IND | BPF_B] = true,
1699  		[BPF_LD | BPF_IND | BPF_H] = true,
1700  		[BPF_LD | BPF_IND | BPF_W] = true,
1701  		[BPF_JMP | BPF_JCOND] = true,
1702  	};
1703  #undef BPF_INSN_3_TBL
1704  #undef BPF_INSN_2_TBL
1705  	return public_insntable[code];
1706  }
1707  
1708  #ifndef CONFIG_BPF_JIT_ALWAYS_ON
1709  /**
1710   *	___bpf_prog_run - run eBPF program on a given context
1711   *	@regs: is the array of MAX_BPF_EXT_REG eBPF pseudo-registers
1712   *	@insn: is the array of eBPF instructions
1713   *
1714   * Decode and execute eBPF instructions.
1715   *
1716   * Return: whatever value is in %BPF_R0 at program exit
1717   */
___bpf_prog_run(u64 * regs,const struct bpf_insn * insn)1718  static u64 ___bpf_prog_run(u64 *regs, const struct bpf_insn *insn)
1719  {
1720  #define BPF_INSN_2_LBL(x, y)    [BPF_##x | BPF_##y] = &&x##_##y
1721  #define BPF_INSN_3_LBL(x, y, z) [BPF_##x | BPF_##y | BPF_##z] = &&x##_##y##_##z
1722  	static const void * const jumptable[256] __annotate_jump_table = {
1723  		[0 ... 255] = &&default_label,
1724  		/* Now overwrite non-defaults ... */
1725  		BPF_INSN_MAP(BPF_INSN_2_LBL, BPF_INSN_3_LBL),
1726  		/* Non-UAPI available opcodes. */
1727  		[BPF_JMP | BPF_CALL_ARGS] = &&JMP_CALL_ARGS,
1728  		[BPF_JMP | BPF_TAIL_CALL] = &&JMP_TAIL_CALL,
1729  		[BPF_ST  | BPF_NOSPEC] = &&ST_NOSPEC,
1730  		[BPF_LDX | BPF_PROBE_MEM | BPF_B] = &&LDX_PROBE_MEM_B,
1731  		[BPF_LDX | BPF_PROBE_MEM | BPF_H] = &&LDX_PROBE_MEM_H,
1732  		[BPF_LDX | BPF_PROBE_MEM | BPF_W] = &&LDX_PROBE_MEM_W,
1733  		[BPF_LDX | BPF_PROBE_MEM | BPF_DW] = &&LDX_PROBE_MEM_DW,
1734  		[BPF_LDX | BPF_PROBE_MEMSX | BPF_B] = &&LDX_PROBE_MEMSX_B,
1735  		[BPF_LDX | BPF_PROBE_MEMSX | BPF_H] = &&LDX_PROBE_MEMSX_H,
1736  		[BPF_LDX | BPF_PROBE_MEMSX | BPF_W] = &&LDX_PROBE_MEMSX_W,
1737  	};
1738  #undef BPF_INSN_3_LBL
1739  #undef BPF_INSN_2_LBL
1740  	u32 tail_call_cnt = 0;
1741  
1742  #define CONT	 ({ insn++; goto select_insn; })
1743  #define CONT_JMP ({ insn++; goto select_insn; })
1744  
1745  select_insn:
1746  	goto *jumptable[insn->code];
1747  
1748  	/* Explicitly mask the register-based shift amounts with 63 or 31
1749  	 * to avoid undefined behavior. Normally this won't affect the
1750  	 * generated code, for example, in case of native 64 bit archs such
1751  	 * as x86-64 or arm64, the compiler is optimizing the AND away for
1752  	 * the interpreter. In case of JITs, each of the JIT backends compiles
1753  	 * the BPF shift operations to machine instructions which produce
1754  	 * implementation-defined results in such a case; the resulting
1755  	 * contents of the register may be arbitrary, but program behaviour
1756  	 * as a whole remains defined. In other words, in case of JIT backends,
1757  	 * the AND must /not/ be added to the emitted LSH/RSH/ARSH translation.
1758  	 */
1759  	/* ALU (shifts) */
1760  #define SHT(OPCODE, OP)					\
1761  	ALU64_##OPCODE##_X:				\
1762  		DST = DST OP (SRC & 63);		\
1763  		CONT;					\
1764  	ALU_##OPCODE##_X:				\
1765  		DST = (u32) DST OP ((u32) SRC & 31);	\
1766  		CONT;					\
1767  	ALU64_##OPCODE##_K:				\
1768  		DST = DST OP IMM;			\
1769  		CONT;					\
1770  	ALU_##OPCODE##_K:				\
1771  		DST = (u32) DST OP (u32) IMM;		\
1772  		CONT;
1773  	/* ALU (rest) */
1774  #define ALU(OPCODE, OP)					\
1775  	ALU64_##OPCODE##_X:				\
1776  		DST = DST OP SRC;			\
1777  		CONT;					\
1778  	ALU_##OPCODE##_X:				\
1779  		DST = (u32) DST OP (u32) SRC;		\
1780  		CONT;					\
1781  	ALU64_##OPCODE##_K:				\
1782  		DST = DST OP IMM;			\
1783  		CONT;					\
1784  	ALU_##OPCODE##_K:				\
1785  		DST = (u32) DST OP (u32) IMM;		\
1786  		CONT;
1787  	ALU(ADD,  +)
1788  	ALU(SUB,  -)
1789  	ALU(AND,  &)
1790  	ALU(OR,   |)
1791  	ALU(XOR,  ^)
1792  	ALU(MUL,  *)
1793  	SHT(LSH, <<)
1794  	SHT(RSH, >>)
1795  #undef SHT
1796  #undef ALU
1797  	ALU_NEG:
1798  		DST = (u32) -DST;
1799  		CONT;
1800  	ALU64_NEG:
1801  		DST = -DST;
1802  		CONT;
1803  	ALU_MOV_X:
1804  		switch (OFF) {
1805  		case 0:
1806  			DST = (u32) SRC;
1807  			break;
1808  		case 8:
1809  			DST = (u32)(s8) SRC;
1810  			break;
1811  		case 16:
1812  			DST = (u32)(s16) SRC;
1813  			break;
1814  		}
1815  		CONT;
1816  	ALU_MOV_K:
1817  		DST = (u32) IMM;
1818  		CONT;
1819  	ALU64_MOV_X:
1820  		switch (OFF) {
1821  		case 0:
1822  			DST = SRC;
1823  			break;
1824  		case 8:
1825  			DST = (s8) SRC;
1826  			break;
1827  		case 16:
1828  			DST = (s16) SRC;
1829  			break;
1830  		case 32:
1831  			DST = (s32) SRC;
1832  			break;
1833  		}
1834  		CONT;
1835  	ALU64_MOV_K:
1836  		DST = IMM;
1837  		CONT;
1838  	LD_IMM_DW:
1839  		DST = (u64) (u32) insn[0].imm | ((u64) (u32) insn[1].imm) << 32;
1840  		insn++;
1841  		CONT;
1842  	ALU_ARSH_X:
1843  		DST = (u64) (u32) (((s32) DST) >> (SRC & 31));
1844  		CONT;
1845  	ALU_ARSH_K:
1846  		DST = (u64) (u32) (((s32) DST) >> IMM);
1847  		CONT;
1848  	ALU64_ARSH_X:
1849  		(*(s64 *) &DST) >>= (SRC & 63);
1850  		CONT;
1851  	ALU64_ARSH_K:
1852  		(*(s64 *) &DST) >>= IMM;
1853  		CONT;
1854  	ALU64_MOD_X:
1855  		switch (OFF) {
1856  		case 0:
1857  			div64_u64_rem(DST, SRC, &AX);
1858  			DST = AX;
1859  			break;
1860  		case 1:
1861  			AX = div64_s64(DST, SRC);
1862  			DST = DST - AX * SRC;
1863  			break;
1864  		}
1865  		CONT;
1866  	ALU_MOD_X:
1867  		switch (OFF) {
1868  		case 0:
1869  			AX = (u32) DST;
1870  			DST = do_div(AX, (u32) SRC);
1871  			break;
1872  		case 1:
1873  			AX = abs((s32)DST);
1874  			AX = do_div(AX, abs((s32)SRC));
1875  			if ((s32)DST < 0)
1876  				DST = (u32)-AX;
1877  			else
1878  				DST = (u32)AX;
1879  			break;
1880  		}
1881  		CONT;
1882  	ALU64_MOD_K:
1883  		switch (OFF) {
1884  		case 0:
1885  			div64_u64_rem(DST, IMM, &AX);
1886  			DST = AX;
1887  			break;
1888  		case 1:
1889  			AX = div64_s64(DST, IMM);
1890  			DST = DST - AX * IMM;
1891  			break;
1892  		}
1893  		CONT;
1894  	ALU_MOD_K:
1895  		switch (OFF) {
1896  		case 0:
1897  			AX = (u32) DST;
1898  			DST = do_div(AX, (u32) IMM);
1899  			break;
1900  		case 1:
1901  			AX = abs((s32)DST);
1902  			AX = do_div(AX, abs((s32)IMM));
1903  			if ((s32)DST < 0)
1904  				DST = (u32)-AX;
1905  			else
1906  				DST = (u32)AX;
1907  			break;
1908  		}
1909  		CONT;
1910  	ALU64_DIV_X:
1911  		switch (OFF) {
1912  		case 0:
1913  			DST = div64_u64(DST, SRC);
1914  			break;
1915  		case 1:
1916  			DST = div64_s64(DST, SRC);
1917  			break;
1918  		}
1919  		CONT;
1920  	ALU_DIV_X:
1921  		switch (OFF) {
1922  		case 0:
1923  			AX = (u32) DST;
1924  			do_div(AX, (u32) SRC);
1925  			DST = (u32) AX;
1926  			break;
1927  		case 1:
1928  			AX = abs((s32)DST);
1929  			do_div(AX, abs((s32)SRC));
1930  			if (((s32)DST < 0) == ((s32)SRC < 0))
1931  				DST = (u32)AX;
1932  			else
1933  				DST = (u32)-AX;
1934  			break;
1935  		}
1936  		CONT;
1937  	ALU64_DIV_K:
1938  		switch (OFF) {
1939  		case 0:
1940  			DST = div64_u64(DST, IMM);
1941  			break;
1942  		case 1:
1943  			DST = div64_s64(DST, IMM);
1944  			break;
1945  		}
1946  		CONT;
1947  	ALU_DIV_K:
1948  		switch (OFF) {
1949  		case 0:
1950  			AX = (u32) DST;
1951  			do_div(AX, (u32) IMM);
1952  			DST = (u32) AX;
1953  			break;
1954  		case 1:
1955  			AX = abs((s32)DST);
1956  			do_div(AX, abs((s32)IMM));
1957  			if (((s32)DST < 0) == ((s32)IMM < 0))
1958  				DST = (u32)AX;
1959  			else
1960  				DST = (u32)-AX;
1961  			break;
1962  		}
1963  		CONT;
1964  	ALU_END_TO_BE:
1965  		switch (IMM) {
1966  		case 16:
1967  			DST = (__force u16) cpu_to_be16(DST);
1968  			break;
1969  		case 32:
1970  			DST = (__force u32) cpu_to_be32(DST);
1971  			break;
1972  		case 64:
1973  			DST = (__force u64) cpu_to_be64(DST);
1974  			break;
1975  		}
1976  		CONT;
1977  	ALU_END_TO_LE:
1978  		switch (IMM) {
1979  		case 16:
1980  			DST = (__force u16) cpu_to_le16(DST);
1981  			break;
1982  		case 32:
1983  			DST = (__force u32) cpu_to_le32(DST);
1984  			break;
1985  		case 64:
1986  			DST = (__force u64) cpu_to_le64(DST);
1987  			break;
1988  		}
1989  		CONT;
1990  	ALU64_END_TO_LE:
1991  		switch (IMM) {
1992  		case 16:
1993  			DST = (__force u16) __swab16(DST);
1994  			break;
1995  		case 32:
1996  			DST = (__force u32) __swab32(DST);
1997  			break;
1998  		case 64:
1999  			DST = (__force u64) __swab64(DST);
2000  			break;
2001  		}
2002  		CONT;
2003  
2004  	/* CALL */
2005  	JMP_CALL:
2006  		/* Function call scratches BPF_R1-BPF_R5 registers,
2007  		 * preserves BPF_R6-BPF_R9, and stores return value
2008  		 * into BPF_R0.
2009  		 */
2010  		BPF_R0 = (__bpf_call_base + insn->imm)(BPF_R1, BPF_R2, BPF_R3,
2011  						       BPF_R4, BPF_R5);
2012  		CONT;
2013  
2014  	JMP_CALL_ARGS:
2015  		BPF_R0 = (__bpf_call_base_args + insn->imm)(BPF_R1, BPF_R2,
2016  							    BPF_R3, BPF_R4,
2017  							    BPF_R5,
2018  							    insn + insn->off + 1);
2019  		CONT;
2020  
2021  	JMP_TAIL_CALL: {
2022  		struct bpf_map *map = (struct bpf_map *) (unsigned long) BPF_R2;
2023  		struct bpf_array *array = container_of(map, struct bpf_array, map);
2024  		struct bpf_prog *prog;
2025  		u32 index = BPF_R3;
2026  
2027  		if (unlikely(index >= array->map.max_entries))
2028  			goto out;
2029  
2030  		if (unlikely(tail_call_cnt >= MAX_TAIL_CALL_CNT))
2031  			goto out;
2032  
2033  		tail_call_cnt++;
2034  
2035  		prog = READ_ONCE(array->ptrs[index]);
2036  		if (!prog)
2037  			goto out;
2038  
2039  		/* ARG1 at this point is guaranteed to point to CTX from
2040  		 * the verifier side due to the fact that the tail call is
2041  		 * handled like a helper, that is, bpf_tail_call_proto,
2042  		 * where arg1_type is ARG_PTR_TO_CTX.
2043  		 */
2044  		insn = prog->insnsi;
2045  		goto select_insn;
2046  out:
2047  		CONT;
2048  	}
2049  	JMP_JA:
2050  		insn += insn->off;
2051  		CONT;
2052  	JMP32_JA:
2053  		insn += insn->imm;
2054  		CONT;
2055  	JMP_EXIT:
2056  		return BPF_R0;
2057  	/* JMP */
2058  #define COND_JMP(SIGN, OPCODE, CMP_OP)				\
2059  	JMP_##OPCODE##_X:					\
2060  		if ((SIGN##64) DST CMP_OP (SIGN##64) SRC) {	\
2061  			insn += insn->off;			\
2062  			CONT_JMP;				\
2063  		}						\
2064  		CONT;						\
2065  	JMP32_##OPCODE##_X:					\
2066  		if ((SIGN##32) DST CMP_OP (SIGN##32) SRC) {	\
2067  			insn += insn->off;			\
2068  			CONT_JMP;				\
2069  		}						\
2070  		CONT;						\
2071  	JMP_##OPCODE##_K:					\
2072  		if ((SIGN##64) DST CMP_OP (SIGN##64) IMM) {	\
2073  			insn += insn->off;			\
2074  			CONT_JMP;				\
2075  		}						\
2076  		CONT;						\
2077  	JMP32_##OPCODE##_K:					\
2078  		if ((SIGN##32) DST CMP_OP (SIGN##32) IMM) {	\
2079  			insn += insn->off;			\
2080  			CONT_JMP;				\
2081  		}						\
2082  		CONT;
2083  	COND_JMP(u, JEQ, ==)
2084  	COND_JMP(u, JNE, !=)
2085  	COND_JMP(u, JGT, >)
2086  	COND_JMP(u, JLT, <)
2087  	COND_JMP(u, JGE, >=)
2088  	COND_JMP(u, JLE, <=)
2089  	COND_JMP(u, JSET, &)
2090  	COND_JMP(s, JSGT, >)
2091  	COND_JMP(s, JSLT, <)
2092  	COND_JMP(s, JSGE, >=)
2093  	COND_JMP(s, JSLE, <=)
2094  #undef COND_JMP
2095  	/* ST, STX and LDX*/
2096  	ST_NOSPEC:
2097  		/* Speculation barrier for mitigating Speculative Store Bypass.
2098  		 * In case of arm64, we rely on the firmware mitigation as
2099  		 * controlled via the ssbd kernel parameter. Whenever the
2100  		 * mitigation is enabled, it works for all of the kernel code
2101  		 * with no need to provide any additional instructions here.
2102  		 * In case of x86, we use 'lfence' insn for mitigation. We
2103  		 * reuse preexisting logic from Spectre v1 mitigation that
2104  		 * happens to produce the required code on x86 for v4 as well.
2105  		 */
2106  		barrier_nospec();
2107  		CONT;
2108  #define LDST(SIZEOP, SIZE)						\
2109  	STX_MEM_##SIZEOP:						\
2110  		*(SIZE *)(unsigned long) (DST + insn->off) = SRC;	\
2111  		CONT;							\
2112  	ST_MEM_##SIZEOP:						\
2113  		*(SIZE *)(unsigned long) (DST + insn->off) = IMM;	\
2114  		CONT;							\
2115  	LDX_MEM_##SIZEOP:						\
2116  		DST = *(SIZE *)(unsigned long) (SRC + insn->off);	\
2117  		CONT;							\
2118  	LDX_PROBE_MEM_##SIZEOP:						\
2119  		bpf_probe_read_kernel_common(&DST, sizeof(SIZE),	\
2120  			      (const void *)(long) (SRC + insn->off));	\
2121  		DST = *((SIZE *)&DST);					\
2122  		CONT;
2123  
2124  	LDST(B,   u8)
2125  	LDST(H,  u16)
2126  	LDST(W,  u32)
2127  	LDST(DW, u64)
2128  #undef LDST
2129  
2130  #define LDSX(SIZEOP, SIZE)						\
2131  	LDX_MEMSX_##SIZEOP:						\
2132  		DST = *(SIZE *)(unsigned long) (SRC + insn->off);	\
2133  		CONT;							\
2134  	LDX_PROBE_MEMSX_##SIZEOP:					\
2135  		bpf_probe_read_kernel_common(&DST, sizeof(SIZE),		\
2136  				      (const void *)(long) (SRC + insn->off));	\
2137  		DST = *((SIZE *)&DST);					\
2138  		CONT;
2139  
2140  	LDSX(B,   s8)
2141  	LDSX(H,  s16)
2142  	LDSX(W,  s32)
2143  #undef LDSX
2144  
2145  #define ATOMIC_ALU_OP(BOP, KOP)						\
2146  		case BOP:						\
2147  			if (BPF_SIZE(insn->code) == BPF_W)		\
2148  				atomic_##KOP((u32) SRC, (atomic_t *)(unsigned long) \
2149  					     (DST + insn->off));	\
2150  			else						\
2151  				atomic64_##KOP((u64) SRC, (atomic64_t *)(unsigned long) \
2152  					       (DST + insn->off));	\
2153  			break;						\
2154  		case BOP | BPF_FETCH:					\
2155  			if (BPF_SIZE(insn->code) == BPF_W)		\
2156  				SRC = (u32) atomic_fetch_##KOP(		\
2157  					(u32) SRC,			\
2158  					(atomic_t *)(unsigned long) (DST + insn->off)); \
2159  			else						\
2160  				SRC = (u64) atomic64_fetch_##KOP(	\
2161  					(u64) SRC,			\
2162  					(atomic64_t *)(unsigned long) (DST + insn->off)); \
2163  			break;
2164  
2165  	STX_ATOMIC_DW:
2166  	STX_ATOMIC_W:
2167  		switch (IMM) {
2168  		ATOMIC_ALU_OP(BPF_ADD, add)
2169  		ATOMIC_ALU_OP(BPF_AND, and)
2170  		ATOMIC_ALU_OP(BPF_OR, or)
2171  		ATOMIC_ALU_OP(BPF_XOR, xor)
2172  #undef ATOMIC_ALU_OP
2173  
2174  		case BPF_XCHG:
2175  			if (BPF_SIZE(insn->code) == BPF_W)
2176  				SRC = (u32) atomic_xchg(
2177  					(atomic_t *)(unsigned long) (DST + insn->off),
2178  					(u32) SRC);
2179  			else
2180  				SRC = (u64) atomic64_xchg(
2181  					(atomic64_t *)(unsigned long) (DST + insn->off),
2182  					(u64) SRC);
2183  			break;
2184  		case BPF_CMPXCHG:
2185  			if (BPF_SIZE(insn->code) == BPF_W)
2186  				BPF_R0 = (u32) atomic_cmpxchg(
2187  					(atomic_t *)(unsigned long) (DST + insn->off),
2188  					(u32) BPF_R0, (u32) SRC);
2189  			else
2190  				BPF_R0 = (u64) atomic64_cmpxchg(
2191  					(atomic64_t *)(unsigned long) (DST + insn->off),
2192  					(u64) BPF_R0, (u64) SRC);
2193  			break;
2194  
2195  		default:
2196  			goto default_label;
2197  		}
2198  		CONT;
2199  
2200  	default_label:
2201  		/* If we ever reach this, we have a bug somewhere. Die hard here
2202  		 * instead of just returning 0; we could be somewhere in a subprog,
2203  		 * so execution could continue otherwise which we do /not/ want.
2204  		 *
2205  		 * Note, verifier whitelists all opcodes in bpf_opcode_in_insntable().
2206  		 */
2207  		pr_warn("BPF interpreter: unknown opcode %02x (imm: 0x%x)\n",
2208  			insn->code, insn->imm);
2209  		BUG_ON(1);
2210  		return 0;
2211  }
2212  
2213  #define PROG_NAME(stack_size) __bpf_prog_run##stack_size
2214  #define DEFINE_BPF_PROG_RUN(stack_size) \
2215  static unsigned int PROG_NAME(stack_size)(const void *ctx, const struct bpf_insn *insn) \
2216  { \
2217  	u64 stack[stack_size / sizeof(u64)]; \
2218  	u64 regs[MAX_BPF_EXT_REG] = {}; \
2219  \
2220  	kmsan_unpoison_memory(stack, sizeof(stack)); \
2221  	FP = (u64) (unsigned long) &stack[ARRAY_SIZE(stack)]; \
2222  	ARG1 = (u64) (unsigned long) ctx; \
2223  	return ___bpf_prog_run(regs, insn); \
2224  }
2225  
2226  #define PROG_NAME_ARGS(stack_size) __bpf_prog_run_args##stack_size
2227  #define DEFINE_BPF_PROG_RUN_ARGS(stack_size) \
2228  static u64 PROG_NAME_ARGS(stack_size)(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5, \
2229  				      const struct bpf_insn *insn) \
2230  { \
2231  	u64 stack[stack_size / sizeof(u64)]; \
2232  	u64 regs[MAX_BPF_EXT_REG]; \
2233  \
2234  	kmsan_unpoison_memory(stack, sizeof(stack)); \
2235  	FP = (u64) (unsigned long) &stack[ARRAY_SIZE(stack)]; \
2236  	BPF_R1 = r1; \
2237  	BPF_R2 = r2; \
2238  	BPF_R3 = r3; \
2239  	BPF_R4 = r4; \
2240  	BPF_R5 = r5; \
2241  	return ___bpf_prog_run(regs, insn); \
2242  }
2243  
2244  #define EVAL1(FN, X) FN(X)
2245  #define EVAL2(FN, X, Y...) FN(X) EVAL1(FN, Y)
2246  #define EVAL3(FN, X, Y...) FN(X) EVAL2(FN, Y)
2247  #define EVAL4(FN, X, Y...) FN(X) EVAL3(FN, Y)
2248  #define EVAL5(FN, X, Y...) FN(X) EVAL4(FN, Y)
2249  #define EVAL6(FN, X, Y...) FN(X) EVAL5(FN, Y)
2250  
2251  EVAL6(DEFINE_BPF_PROG_RUN, 32, 64, 96, 128, 160, 192);
2252  EVAL6(DEFINE_BPF_PROG_RUN, 224, 256, 288, 320, 352, 384);
2253  EVAL4(DEFINE_BPF_PROG_RUN, 416, 448, 480, 512);
2254  
2255  EVAL6(DEFINE_BPF_PROG_RUN_ARGS, 32, 64, 96, 128, 160, 192);
2256  EVAL6(DEFINE_BPF_PROG_RUN_ARGS, 224, 256, 288, 320, 352, 384);
2257  EVAL4(DEFINE_BPF_PROG_RUN_ARGS, 416, 448, 480, 512);
2258  
2259  #define PROG_NAME_LIST(stack_size) PROG_NAME(stack_size),
2260  
2261  static unsigned int (*interpreters[])(const void *ctx,
2262  				      const struct bpf_insn *insn) = {
2263  EVAL6(PROG_NAME_LIST, 32, 64, 96, 128, 160, 192)
2264  EVAL6(PROG_NAME_LIST, 224, 256, 288, 320, 352, 384)
2265  EVAL4(PROG_NAME_LIST, 416, 448, 480, 512)
2266  };
2267  #undef PROG_NAME_LIST
2268  #define PROG_NAME_LIST(stack_size) PROG_NAME_ARGS(stack_size),
2269  static __maybe_unused
2270  u64 (*interpreters_args[])(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5,
2271  			   const struct bpf_insn *insn) = {
2272  EVAL6(PROG_NAME_LIST, 32, 64, 96, 128, 160, 192)
2273  EVAL6(PROG_NAME_LIST, 224, 256, 288, 320, 352, 384)
2274  EVAL4(PROG_NAME_LIST, 416, 448, 480, 512)
2275  };
2276  #undef PROG_NAME_LIST
2277  
2278  #ifdef CONFIG_BPF_SYSCALL
bpf_patch_call_args(struct bpf_insn * insn,u32 stack_depth)2279  void bpf_patch_call_args(struct bpf_insn *insn, u32 stack_depth)
2280  {
2281  	stack_depth = max_t(u32, stack_depth, 1);
2282  	insn->off = (s16) insn->imm;
2283  	insn->imm = interpreters_args[(round_up(stack_depth, 32) / 32) - 1] -
2284  		__bpf_call_base_args;
2285  	insn->code = BPF_JMP | BPF_CALL_ARGS;
2286  }
2287  #endif
2288  #else
__bpf_prog_ret0_warn(const void * ctx,const struct bpf_insn * insn)2289  static unsigned int __bpf_prog_ret0_warn(const void *ctx,
2290  					 const struct bpf_insn *insn)
2291  {
2292  	/* If this handler ever gets executed, then BPF_JIT_ALWAYS_ON
2293  	 * is not working properly, so warn about it!
2294  	 */
2295  	WARN_ON_ONCE(1);
2296  	return 0;
2297  }
2298  #endif
2299  
bpf_prog_map_compatible(struct bpf_map * map,const struct bpf_prog * fp)2300  bool bpf_prog_map_compatible(struct bpf_map *map,
2301  			     const struct bpf_prog *fp)
2302  {
2303  	enum bpf_prog_type prog_type = resolve_prog_type(fp);
2304  	bool ret;
2305  	struct bpf_prog_aux *aux = fp->aux;
2306  
2307  	if (fp->kprobe_override)
2308  		return false;
2309  
2310  	/* XDP programs inserted into maps are not guaranteed to run on
2311  	 * a particular netdev (and can run outside driver context entirely
2312  	 * in the case of devmap and cpumap). Until device checks
2313  	 * are implemented, prohibit adding dev-bound programs to program maps.
2314  	 */
2315  	if (bpf_prog_is_dev_bound(aux))
2316  		return false;
2317  
2318  	spin_lock(&map->owner.lock);
2319  	if (!map->owner.type) {
2320  		/* There's no owner yet where we could check for
2321  		 * compatibility.
2322  		 */
2323  		map->owner.type  = prog_type;
2324  		map->owner.jited = fp->jited;
2325  		map->owner.xdp_has_frags = aux->xdp_has_frags;
2326  		map->owner.attach_func_proto = aux->attach_func_proto;
2327  		ret = true;
2328  	} else {
2329  		ret = map->owner.type  == prog_type &&
2330  		      map->owner.jited == fp->jited &&
2331  		      map->owner.xdp_has_frags == aux->xdp_has_frags;
2332  		if (ret &&
2333  		    map->owner.attach_func_proto != aux->attach_func_proto) {
2334  			switch (prog_type) {
2335  			case BPF_PROG_TYPE_TRACING:
2336  			case BPF_PROG_TYPE_LSM:
2337  			case BPF_PROG_TYPE_EXT:
2338  			case BPF_PROG_TYPE_STRUCT_OPS:
2339  				ret = false;
2340  				break;
2341  			default:
2342  				break;
2343  			}
2344  		}
2345  	}
2346  	spin_unlock(&map->owner.lock);
2347  
2348  	return ret;
2349  }
2350  
bpf_check_tail_call(const struct bpf_prog * fp)2351  static int bpf_check_tail_call(const struct bpf_prog *fp)
2352  {
2353  	struct bpf_prog_aux *aux = fp->aux;
2354  	int i, ret = 0;
2355  
2356  	mutex_lock(&aux->used_maps_mutex);
2357  	for (i = 0; i < aux->used_map_cnt; i++) {
2358  		struct bpf_map *map = aux->used_maps[i];
2359  
2360  		if (!map_type_contains_progs(map))
2361  			continue;
2362  
2363  		if (!bpf_prog_map_compatible(map, fp)) {
2364  			ret = -EINVAL;
2365  			goto out;
2366  		}
2367  	}
2368  
2369  out:
2370  	mutex_unlock(&aux->used_maps_mutex);
2371  	return ret;
2372  }
2373  
bpf_prog_select_func(struct bpf_prog * fp)2374  static void bpf_prog_select_func(struct bpf_prog *fp)
2375  {
2376  #ifndef CONFIG_BPF_JIT_ALWAYS_ON
2377  	u32 stack_depth = max_t(u32, fp->aux->stack_depth, 1);
2378  
2379  	fp->bpf_func = interpreters[(round_up(stack_depth, 32) / 32) - 1];
2380  #else
2381  	fp->bpf_func = __bpf_prog_ret0_warn;
2382  #endif
2383  }
2384  
2385  /**
2386   *	bpf_prog_select_runtime - select exec runtime for BPF program
2387   *	@fp: bpf_prog populated with BPF program
2388   *	@err: pointer to error variable
2389   *
2390   * Try to JIT eBPF program, if JIT is not available, use interpreter.
2391   * The BPF program will be executed via bpf_prog_run() function.
2392   *
2393   * Return: the &fp argument along with &err set to 0 for success or
2394   * a negative errno code on failure
2395   */
bpf_prog_select_runtime(struct bpf_prog * fp,int * err)2396  struct bpf_prog *bpf_prog_select_runtime(struct bpf_prog *fp, int *err)
2397  {
2398  	/* In case of BPF to BPF calls, verifier did all the prep
2399  	 * work with regards to JITing, etc.
2400  	 */
2401  	bool jit_needed = false;
2402  
2403  	if (fp->bpf_func)
2404  		goto finalize;
2405  
2406  	if (IS_ENABLED(CONFIG_BPF_JIT_ALWAYS_ON) ||
2407  	    bpf_prog_has_kfunc_call(fp))
2408  		jit_needed = true;
2409  
2410  	bpf_prog_select_func(fp);
2411  
2412  	/* eBPF JITs can rewrite the program in case constant
2413  	 * blinding is active. However, in case of error during
2414  	 * blinding, bpf_int_jit_compile() must always return a
2415  	 * valid program, which in this case would simply not
2416  	 * be JITed, but falls back to the interpreter.
2417  	 */
2418  	if (!bpf_prog_is_offloaded(fp->aux)) {
2419  		*err = bpf_prog_alloc_jited_linfo(fp);
2420  		if (*err)
2421  			return fp;
2422  
2423  		fp = bpf_int_jit_compile(fp);
2424  		bpf_prog_jit_attempt_done(fp);
2425  		if (!fp->jited && jit_needed) {
2426  			*err = -ENOTSUPP;
2427  			return fp;
2428  		}
2429  	} else {
2430  		*err = bpf_prog_offload_compile(fp);
2431  		if (*err)
2432  			return fp;
2433  	}
2434  
2435  finalize:
2436  	*err = bpf_prog_lock_ro(fp);
2437  	if (*err)
2438  		return fp;
2439  
2440  	/* The tail call compatibility check can only be done at
2441  	 * this late stage as we need to determine, if we deal
2442  	 * with JITed or non JITed program concatenations and not
2443  	 * all eBPF JITs might immediately support all features.
2444  	 */
2445  	*err = bpf_check_tail_call(fp);
2446  
2447  	return fp;
2448  }
2449  EXPORT_SYMBOL_GPL(bpf_prog_select_runtime);
2450  
__bpf_prog_ret1(const void * ctx,const struct bpf_insn * insn)2451  static unsigned int __bpf_prog_ret1(const void *ctx,
2452  				    const struct bpf_insn *insn)
2453  {
2454  	return 1;
2455  }
2456  
2457  static struct bpf_prog_dummy {
2458  	struct bpf_prog prog;
2459  } dummy_bpf_prog = {
2460  	.prog = {
2461  		.bpf_func = __bpf_prog_ret1,
2462  	},
2463  };
2464  
2465  struct bpf_empty_prog_array bpf_empty_prog_array = {
2466  	.null_prog = NULL,
2467  };
2468  EXPORT_SYMBOL(bpf_empty_prog_array);
2469  
bpf_prog_array_alloc(u32 prog_cnt,gfp_t flags)2470  struct bpf_prog_array *bpf_prog_array_alloc(u32 prog_cnt, gfp_t flags)
2471  {
2472  	struct bpf_prog_array *p;
2473  
2474  	if (prog_cnt)
2475  		p = kzalloc(struct_size(p, items, prog_cnt + 1), flags);
2476  	else
2477  		p = &bpf_empty_prog_array.hdr;
2478  
2479  	return p;
2480  }
2481  
bpf_prog_array_free(struct bpf_prog_array * progs)2482  void bpf_prog_array_free(struct bpf_prog_array *progs)
2483  {
2484  	if (!progs || progs == &bpf_empty_prog_array.hdr)
2485  		return;
2486  	kfree_rcu(progs, rcu);
2487  }
2488  
__bpf_prog_array_free_sleepable_cb(struct rcu_head * rcu)2489  static void __bpf_prog_array_free_sleepable_cb(struct rcu_head *rcu)
2490  {
2491  	struct bpf_prog_array *progs;
2492  
2493  	/* If RCU Tasks Trace grace period implies RCU grace period, there is
2494  	 * no need to call kfree_rcu(), just call kfree() directly.
2495  	 */
2496  	progs = container_of(rcu, struct bpf_prog_array, rcu);
2497  	if (rcu_trace_implies_rcu_gp())
2498  		kfree(progs);
2499  	else
2500  		kfree_rcu(progs, rcu);
2501  }
2502  
bpf_prog_array_free_sleepable(struct bpf_prog_array * progs)2503  void bpf_prog_array_free_sleepable(struct bpf_prog_array *progs)
2504  {
2505  	if (!progs || progs == &bpf_empty_prog_array.hdr)
2506  		return;
2507  	call_rcu_tasks_trace(&progs->rcu, __bpf_prog_array_free_sleepable_cb);
2508  }
2509  
bpf_prog_array_length(struct bpf_prog_array * array)2510  int bpf_prog_array_length(struct bpf_prog_array *array)
2511  {
2512  	struct bpf_prog_array_item *item;
2513  	u32 cnt = 0;
2514  
2515  	for (item = array->items; item->prog; item++)
2516  		if (item->prog != &dummy_bpf_prog.prog)
2517  			cnt++;
2518  	return cnt;
2519  }
2520  
bpf_prog_array_is_empty(struct bpf_prog_array * array)2521  bool bpf_prog_array_is_empty(struct bpf_prog_array *array)
2522  {
2523  	struct bpf_prog_array_item *item;
2524  
2525  	for (item = array->items; item->prog; item++)
2526  		if (item->prog != &dummy_bpf_prog.prog)
2527  			return false;
2528  	return true;
2529  }
2530  
bpf_prog_array_copy_core(struct bpf_prog_array * array,u32 * prog_ids,u32 request_cnt)2531  static bool bpf_prog_array_copy_core(struct bpf_prog_array *array,
2532  				     u32 *prog_ids,
2533  				     u32 request_cnt)
2534  {
2535  	struct bpf_prog_array_item *item;
2536  	int i = 0;
2537  
2538  	for (item = array->items; item->prog; item++) {
2539  		if (item->prog == &dummy_bpf_prog.prog)
2540  			continue;
2541  		prog_ids[i] = item->prog->aux->id;
2542  		if (++i == request_cnt) {
2543  			item++;
2544  			break;
2545  		}
2546  	}
2547  
2548  	return !!(item->prog);
2549  }
2550  
bpf_prog_array_copy_to_user(struct bpf_prog_array * array,__u32 __user * prog_ids,u32 cnt)2551  int bpf_prog_array_copy_to_user(struct bpf_prog_array *array,
2552  				__u32 __user *prog_ids, u32 cnt)
2553  {
2554  	unsigned long err = 0;
2555  	bool nospc;
2556  	u32 *ids;
2557  
2558  	/* users of this function are doing:
2559  	 * cnt = bpf_prog_array_length();
2560  	 * if (cnt > 0)
2561  	 *     bpf_prog_array_copy_to_user(..., cnt);
2562  	 * so below kcalloc doesn't need extra cnt > 0 check.
2563  	 */
2564  	ids = kcalloc(cnt, sizeof(u32), GFP_USER | __GFP_NOWARN);
2565  	if (!ids)
2566  		return -ENOMEM;
2567  	nospc = bpf_prog_array_copy_core(array, ids, cnt);
2568  	err = copy_to_user(prog_ids, ids, cnt * sizeof(u32));
2569  	kfree(ids);
2570  	if (err)
2571  		return -EFAULT;
2572  	if (nospc)
2573  		return -ENOSPC;
2574  	return 0;
2575  }
2576  
bpf_prog_array_delete_safe(struct bpf_prog_array * array,struct bpf_prog * old_prog)2577  void bpf_prog_array_delete_safe(struct bpf_prog_array *array,
2578  				struct bpf_prog *old_prog)
2579  {
2580  	struct bpf_prog_array_item *item;
2581  
2582  	for (item = array->items; item->prog; item++)
2583  		if (item->prog == old_prog) {
2584  			WRITE_ONCE(item->prog, &dummy_bpf_prog.prog);
2585  			break;
2586  		}
2587  }
2588  
2589  /**
2590   * bpf_prog_array_delete_safe_at() - Replaces the program at the given
2591   *                                   index into the program array with
2592   *                                   a dummy no-op program.
2593   * @array: a bpf_prog_array
2594   * @index: the index of the program to replace
2595   *
2596   * Skips over dummy programs, by not counting them, when calculating
2597   * the position of the program to replace.
2598   *
2599   * Return:
2600   * * 0		- Success
2601   * * -EINVAL	- Invalid index value. Must be a non-negative integer.
2602   * * -ENOENT	- Index out of range
2603   */
bpf_prog_array_delete_safe_at(struct bpf_prog_array * array,int index)2604  int bpf_prog_array_delete_safe_at(struct bpf_prog_array *array, int index)
2605  {
2606  	return bpf_prog_array_update_at(array, index, &dummy_bpf_prog.prog);
2607  }
2608  
2609  /**
2610   * bpf_prog_array_update_at() - Updates the program at the given index
2611   *                              into the program array.
2612   * @array: a bpf_prog_array
2613   * @index: the index of the program to update
2614   * @prog: the program to insert into the array
2615   *
2616   * Skips over dummy programs, by not counting them, when calculating
2617   * the position of the program to update.
2618   *
2619   * Return:
2620   * * 0		- Success
2621   * * -EINVAL	- Invalid index value. Must be a non-negative integer.
2622   * * -ENOENT	- Index out of range
2623   */
bpf_prog_array_update_at(struct bpf_prog_array * array,int index,struct bpf_prog * prog)2624  int bpf_prog_array_update_at(struct bpf_prog_array *array, int index,
2625  			     struct bpf_prog *prog)
2626  {
2627  	struct bpf_prog_array_item *item;
2628  
2629  	if (unlikely(index < 0))
2630  		return -EINVAL;
2631  
2632  	for (item = array->items; item->prog; item++) {
2633  		if (item->prog == &dummy_bpf_prog.prog)
2634  			continue;
2635  		if (!index) {
2636  			WRITE_ONCE(item->prog, prog);
2637  			return 0;
2638  		}
2639  		index--;
2640  	}
2641  	return -ENOENT;
2642  }
2643  
bpf_prog_array_copy(struct bpf_prog_array * old_array,struct bpf_prog * exclude_prog,struct bpf_prog * include_prog,u64 bpf_cookie,struct bpf_prog_array ** new_array)2644  int bpf_prog_array_copy(struct bpf_prog_array *old_array,
2645  			struct bpf_prog *exclude_prog,
2646  			struct bpf_prog *include_prog,
2647  			u64 bpf_cookie,
2648  			struct bpf_prog_array **new_array)
2649  {
2650  	int new_prog_cnt, carry_prog_cnt = 0;
2651  	struct bpf_prog_array_item *existing, *new;
2652  	struct bpf_prog_array *array;
2653  	bool found_exclude = false;
2654  
2655  	/* Figure out how many existing progs we need to carry over to
2656  	 * the new array.
2657  	 */
2658  	if (old_array) {
2659  		existing = old_array->items;
2660  		for (; existing->prog; existing++) {
2661  			if (existing->prog == exclude_prog) {
2662  				found_exclude = true;
2663  				continue;
2664  			}
2665  			if (existing->prog != &dummy_bpf_prog.prog)
2666  				carry_prog_cnt++;
2667  			if (existing->prog == include_prog)
2668  				return -EEXIST;
2669  		}
2670  	}
2671  
2672  	if (exclude_prog && !found_exclude)
2673  		return -ENOENT;
2674  
2675  	/* How many progs (not NULL) will be in the new array? */
2676  	new_prog_cnt = carry_prog_cnt;
2677  	if (include_prog)
2678  		new_prog_cnt += 1;
2679  
2680  	/* Do we have any prog (not NULL) in the new array? */
2681  	if (!new_prog_cnt) {
2682  		*new_array = NULL;
2683  		return 0;
2684  	}
2685  
2686  	/* +1 as the end of prog_array is marked with NULL */
2687  	array = bpf_prog_array_alloc(new_prog_cnt + 1, GFP_KERNEL);
2688  	if (!array)
2689  		return -ENOMEM;
2690  	new = array->items;
2691  
2692  	/* Fill in the new prog array */
2693  	if (carry_prog_cnt) {
2694  		existing = old_array->items;
2695  		for (; existing->prog; existing++) {
2696  			if (existing->prog == exclude_prog ||
2697  			    existing->prog == &dummy_bpf_prog.prog)
2698  				continue;
2699  
2700  			new->prog = existing->prog;
2701  			new->bpf_cookie = existing->bpf_cookie;
2702  			new++;
2703  		}
2704  	}
2705  	if (include_prog) {
2706  		new->prog = include_prog;
2707  		new->bpf_cookie = bpf_cookie;
2708  		new++;
2709  	}
2710  	new->prog = NULL;
2711  	*new_array = array;
2712  	return 0;
2713  }
2714  
bpf_prog_array_copy_info(struct bpf_prog_array * array,u32 * prog_ids,u32 request_cnt,u32 * prog_cnt)2715  int bpf_prog_array_copy_info(struct bpf_prog_array *array,
2716  			     u32 *prog_ids, u32 request_cnt,
2717  			     u32 *prog_cnt)
2718  {
2719  	u32 cnt = 0;
2720  
2721  	if (array)
2722  		cnt = bpf_prog_array_length(array);
2723  
2724  	*prog_cnt = cnt;
2725  
2726  	/* return early if user requested only program count or nothing to copy */
2727  	if (!request_cnt || !cnt)
2728  		return 0;
2729  
2730  	/* this function is called under trace/bpf_trace.c: bpf_event_mutex */
2731  	return bpf_prog_array_copy_core(array, prog_ids, request_cnt) ? -ENOSPC
2732  								     : 0;
2733  }
2734  
__bpf_free_used_maps(struct bpf_prog_aux * aux,struct bpf_map ** used_maps,u32 len)2735  void __bpf_free_used_maps(struct bpf_prog_aux *aux,
2736  			  struct bpf_map **used_maps, u32 len)
2737  {
2738  	struct bpf_map *map;
2739  	bool sleepable;
2740  	u32 i;
2741  
2742  	sleepable = aux->prog->sleepable;
2743  	for (i = 0; i < len; i++) {
2744  		map = used_maps[i];
2745  		if (map->ops->map_poke_untrack)
2746  			map->ops->map_poke_untrack(map, aux);
2747  		if (sleepable)
2748  			atomic64_dec(&map->sleepable_refcnt);
2749  		bpf_map_put(map);
2750  	}
2751  }
2752  
bpf_free_used_maps(struct bpf_prog_aux * aux)2753  static void bpf_free_used_maps(struct bpf_prog_aux *aux)
2754  {
2755  	__bpf_free_used_maps(aux, aux->used_maps, aux->used_map_cnt);
2756  	kfree(aux->used_maps);
2757  }
2758  
__bpf_free_used_btfs(struct btf_mod_pair * used_btfs,u32 len)2759  void __bpf_free_used_btfs(struct btf_mod_pair *used_btfs, u32 len)
2760  {
2761  #ifdef CONFIG_BPF_SYSCALL
2762  	struct btf_mod_pair *btf_mod;
2763  	u32 i;
2764  
2765  	for (i = 0; i < len; i++) {
2766  		btf_mod = &used_btfs[i];
2767  		if (btf_mod->module)
2768  			module_put(btf_mod->module);
2769  		btf_put(btf_mod->btf);
2770  	}
2771  #endif
2772  }
2773  
bpf_free_used_btfs(struct bpf_prog_aux * aux)2774  static void bpf_free_used_btfs(struct bpf_prog_aux *aux)
2775  {
2776  	__bpf_free_used_btfs(aux->used_btfs, aux->used_btf_cnt);
2777  	kfree(aux->used_btfs);
2778  }
2779  
bpf_prog_free_deferred(struct work_struct * work)2780  static void bpf_prog_free_deferred(struct work_struct *work)
2781  {
2782  	struct bpf_prog_aux *aux;
2783  	int i;
2784  
2785  	aux = container_of(work, struct bpf_prog_aux, work);
2786  #ifdef CONFIG_BPF_SYSCALL
2787  	bpf_free_kfunc_btf_tab(aux->kfunc_btf_tab);
2788  #endif
2789  #ifdef CONFIG_CGROUP_BPF
2790  	if (aux->cgroup_atype != CGROUP_BPF_ATTACH_TYPE_INVALID)
2791  		bpf_cgroup_atype_put(aux->cgroup_atype);
2792  #endif
2793  	bpf_free_used_maps(aux);
2794  	bpf_free_used_btfs(aux);
2795  	if (bpf_prog_is_dev_bound(aux))
2796  		bpf_prog_dev_bound_destroy(aux->prog);
2797  #ifdef CONFIG_PERF_EVENTS
2798  	if (aux->prog->has_callchain_buf)
2799  		put_callchain_buffers();
2800  #endif
2801  	if (aux->dst_trampoline)
2802  		bpf_trampoline_put(aux->dst_trampoline);
2803  	for (i = 0; i < aux->real_func_cnt; i++) {
2804  		/* We can just unlink the subprog poke descriptor table as
2805  		 * it was originally linked to the main program and is also
2806  		 * released along with it.
2807  		 */
2808  		aux->func[i]->aux->poke_tab = NULL;
2809  		bpf_jit_free(aux->func[i]);
2810  	}
2811  	if (aux->real_func_cnt) {
2812  		kfree(aux->func);
2813  		bpf_prog_unlock_free(aux->prog);
2814  	} else {
2815  		bpf_jit_free(aux->prog);
2816  	}
2817  }
2818  
bpf_prog_free(struct bpf_prog * fp)2819  void bpf_prog_free(struct bpf_prog *fp)
2820  {
2821  	struct bpf_prog_aux *aux = fp->aux;
2822  
2823  	if (aux->dst_prog)
2824  		bpf_prog_put(aux->dst_prog);
2825  	bpf_token_put(aux->token);
2826  	INIT_WORK(&aux->work, bpf_prog_free_deferred);
2827  	schedule_work(&aux->work);
2828  }
2829  EXPORT_SYMBOL_GPL(bpf_prog_free);
2830  
2831  /* RNG for unprivileged user space with separated state from prandom_u32(). */
2832  static DEFINE_PER_CPU(struct rnd_state, bpf_user_rnd_state);
2833  
bpf_user_rnd_init_once(void)2834  void bpf_user_rnd_init_once(void)
2835  {
2836  	prandom_init_once(&bpf_user_rnd_state);
2837  }
2838  
BPF_CALL_0(bpf_user_rnd_u32)2839  BPF_CALL_0(bpf_user_rnd_u32)
2840  {
2841  	/* Should someone ever have the rather unwise idea to use some
2842  	 * of the registers passed into this function, then note that
2843  	 * this function is called from native eBPF and classic-to-eBPF
2844  	 * transformations. Register assignments from both sides are
2845  	 * different, f.e. classic always sets fn(ctx, A, X) here.
2846  	 */
2847  	struct rnd_state *state;
2848  	u32 res;
2849  
2850  	state = &get_cpu_var(bpf_user_rnd_state);
2851  	res = prandom_u32_state(state);
2852  	put_cpu_var(bpf_user_rnd_state);
2853  
2854  	return res;
2855  }
2856  
BPF_CALL_0(bpf_get_raw_cpu_id)2857  BPF_CALL_0(bpf_get_raw_cpu_id)
2858  {
2859  	return raw_smp_processor_id();
2860  }
2861  
2862  /* Weak definitions of helper functions in case we don't have bpf syscall. */
2863  const struct bpf_func_proto bpf_map_lookup_elem_proto __weak;
2864  const struct bpf_func_proto bpf_map_update_elem_proto __weak;
2865  const struct bpf_func_proto bpf_map_delete_elem_proto __weak;
2866  const struct bpf_func_proto bpf_map_push_elem_proto __weak;
2867  const struct bpf_func_proto bpf_map_pop_elem_proto __weak;
2868  const struct bpf_func_proto bpf_map_peek_elem_proto __weak;
2869  const struct bpf_func_proto bpf_map_lookup_percpu_elem_proto __weak;
2870  const struct bpf_func_proto bpf_spin_lock_proto __weak;
2871  const struct bpf_func_proto bpf_spin_unlock_proto __weak;
2872  const struct bpf_func_proto bpf_jiffies64_proto __weak;
2873  
2874  const struct bpf_func_proto bpf_get_prandom_u32_proto __weak;
2875  const struct bpf_func_proto bpf_get_smp_processor_id_proto __weak;
2876  const struct bpf_func_proto bpf_get_numa_node_id_proto __weak;
2877  const struct bpf_func_proto bpf_ktime_get_ns_proto __weak;
2878  const struct bpf_func_proto bpf_ktime_get_boot_ns_proto __weak;
2879  const struct bpf_func_proto bpf_ktime_get_coarse_ns_proto __weak;
2880  const struct bpf_func_proto bpf_ktime_get_tai_ns_proto __weak;
2881  
2882  const struct bpf_func_proto bpf_get_current_pid_tgid_proto __weak;
2883  const struct bpf_func_proto bpf_get_current_uid_gid_proto __weak;
2884  const struct bpf_func_proto bpf_get_current_comm_proto __weak;
2885  const struct bpf_func_proto bpf_get_current_cgroup_id_proto __weak;
2886  const struct bpf_func_proto bpf_get_current_ancestor_cgroup_id_proto __weak;
2887  const struct bpf_func_proto bpf_get_local_storage_proto __weak;
2888  const struct bpf_func_proto bpf_get_ns_current_pid_tgid_proto __weak;
2889  const struct bpf_func_proto bpf_snprintf_btf_proto __weak;
2890  const struct bpf_func_proto bpf_seq_printf_btf_proto __weak;
2891  const struct bpf_func_proto bpf_set_retval_proto __weak;
2892  const struct bpf_func_proto bpf_get_retval_proto __weak;
2893  
bpf_get_trace_printk_proto(void)2894  const struct bpf_func_proto * __weak bpf_get_trace_printk_proto(void)
2895  {
2896  	return NULL;
2897  }
2898  
bpf_get_trace_vprintk_proto(void)2899  const struct bpf_func_proto * __weak bpf_get_trace_vprintk_proto(void)
2900  {
2901  	return NULL;
2902  }
2903  
2904  u64 __weak
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)2905  bpf_event_output(struct bpf_map *map, u64 flags, void *meta, u64 meta_size,
2906  		 void *ctx, u64 ctx_size, bpf_ctx_copy_t ctx_copy)
2907  {
2908  	return -ENOTSUPP;
2909  }
2910  EXPORT_SYMBOL_GPL(bpf_event_output);
2911  
2912  /* Always built-in helper functions. */
2913  const struct bpf_func_proto bpf_tail_call_proto = {
2914  	.func		= NULL,
2915  	.gpl_only	= false,
2916  	.ret_type	= RET_VOID,
2917  	.arg1_type	= ARG_PTR_TO_CTX,
2918  	.arg2_type	= ARG_CONST_MAP_PTR,
2919  	.arg3_type	= ARG_ANYTHING,
2920  };
2921  
2922  /* Stub for JITs that only support cBPF. eBPF programs are interpreted.
2923   * It is encouraged to implement bpf_int_jit_compile() instead, so that
2924   * eBPF and implicitly also cBPF can get JITed!
2925   */
bpf_int_jit_compile(struct bpf_prog * prog)2926  struct bpf_prog * __weak bpf_int_jit_compile(struct bpf_prog *prog)
2927  {
2928  	return prog;
2929  }
2930  
2931  /* Stub for JITs that support eBPF. All cBPF code gets transformed into
2932   * eBPF by the kernel and is later compiled by bpf_int_jit_compile().
2933   */
bpf_jit_compile(struct bpf_prog * prog)2934  void __weak bpf_jit_compile(struct bpf_prog *prog)
2935  {
2936  }
2937  
bpf_helper_changes_pkt_data(void * func)2938  bool __weak bpf_helper_changes_pkt_data(void *func)
2939  {
2940  	return false;
2941  }
2942  
2943  /* Return TRUE if the JIT backend wants verifier to enable sub-register usage
2944   * analysis code and wants explicit zero extension inserted by verifier.
2945   * Otherwise, return FALSE.
2946   *
2947   * The verifier inserts an explicit zero extension after BPF_CMPXCHGs even if
2948   * you don't override this. JITs that don't want these extra insns can detect
2949   * them using insn_is_zext.
2950   */
bpf_jit_needs_zext(void)2951  bool __weak bpf_jit_needs_zext(void)
2952  {
2953  	return false;
2954  }
2955  
2956  /* Return true if the JIT inlines the call to the helper corresponding to
2957   * the imm.
2958   *
2959   * The verifier will not patch the insn->imm for the call to the helper if
2960   * this returns true.
2961   */
bpf_jit_inlines_helper_call(s32 imm)2962  bool __weak bpf_jit_inlines_helper_call(s32 imm)
2963  {
2964  	return false;
2965  }
2966  
2967  /* Return TRUE if the JIT backend supports mixing bpf2bpf and tailcalls. */
bpf_jit_supports_subprog_tailcalls(void)2968  bool __weak bpf_jit_supports_subprog_tailcalls(void)
2969  {
2970  	return false;
2971  }
2972  
bpf_jit_supports_percpu_insn(void)2973  bool __weak bpf_jit_supports_percpu_insn(void)
2974  {
2975  	return false;
2976  }
2977  
bpf_jit_supports_kfunc_call(void)2978  bool __weak bpf_jit_supports_kfunc_call(void)
2979  {
2980  	return false;
2981  }
2982  
bpf_jit_supports_far_kfunc_call(void)2983  bool __weak bpf_jit_supports_far_kfunc_call(void)
2984  {
2985  	return false;
2986  }
2987  
bpf_jit_supports_arena(void)2988  bool __weak bpf_jit_supports_arena(void)
2989  {
2990  	return false;
2991  }
2992  
bpf_jit_supports_insn(struct bpf_insn * insn,bool in_arena)2993  bool __weak bpf_jit_supports_insn(struct bpf_insn *insn, bool in_arena)
2994  {
2995  	return false;
2996  }
2997  
bpf_arch_uaddress_limit(void)2998  u64 __weak bpf_arch_uaddress_limit(void)
2999  {
3000  #if defined(CONFIG_64BIT) && defined(CONFIG_ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE)
3001  	return TASK_SIZE;
3002  #else
3003  	return 0;
3004  #endif
3005  }
3006  
3007  /* Return TRUE if the JIT backend satisfies the following two conditions:
3008   * 1) JIT backend supports atomic_xchg() on pointer-sized words.
3009   * 2) Under the specific arch, the implementation of xchg() is the same
3010   *    as atomic_xchg() on pointer-sized words.
3011   */
bpf_jit_supports_ptr_xchg(void)3012  bool __weak bpf_jit_supports_ptr_xchg(void)
3013  {
3014  	return false;
3015  }
3016  
3017  /* To execute LD_ABS/LD_IND instructions __bpf_prog_run() may call
3018   * skb_copy_bits(), so provide a weak definition of it for NET-less config.
3019   */
skb_copy_bits(const struct sk_buff * skb,int offset,void * to,int len)3020  int __weak skb_copy_bits(const struct sk_buff *skb, int offset, void *to,
3021  			 int len)
3022  {
3023  	return -EFAULT;
3024  }
3025  
bpf_arch_text_poke(void * ip,enum bpf_text_poke_type t,void * addr1,void * addr2)3026  int __weak bpf_arch_text_poke(void *ip, enum bpf_text_poke_type t,
3027  			      void *addr1, void *addr2)
3028  {
3029  	return -ENOTSUPP;
3030  }
3031  
bpf_arch_text_copy(void * dst,void * src,size_t len)3032  void * __weak bpf_arch_text_copy(void *dst, void *src, size_t len)
3033  {
3034  	return ERR_PTR(-ENOTSUPP);
3035  }
3036  
bpf_arch_text_invalidate(void * dst,size_t len)3037  int __weak bpf_arch_text_invalidate(void *dst, size_t len)
3038  {
3039  	return -ENOTSUPP;
3040  }
3041  
bpf_jit_supports_exceptions(void)3042  bool __weak bpf_jit_supports_exceptions(void)
3043  {
3044  	return false;
3045  }
3046  
arch_bpf_stack_walk(bool (* consume_fn)(void * cookie,u64 ip,u64 sp,u64 bp),void * cookie)3047  void __weak arch_bpf_stack_walk(bool (*consume_fn)(void *cookie, u64 ip, u64 sp, u64 bp), void *cookie)
3048  {
3049  }
3050  
3051  /* for configs without MMU or 32-bit */
3052  __weak const struct bpf_map_ops arena_map_ops;
bpf_arena_get_user_vm_start(struct bpf_arena * arena)3053  __weak u64 bpf_arena_get_user_vm_start(struct bpf_arena *arena)
3054  {
3055  	return 0;
3056  }
bpf_arena_get_kern_vm_start(struct bpf_arena * arena)3057  __weak u64 bpf_arena_get_kern_vm_start(struct bpf_arena *arena)
3058  {
3059  	return 0;
3060  }
3061  
3062  #ifdef CONFIG_BPF_SYSCALL
bpf_global_ma_init(void)3063  static int __init bpf_global_ma_init(void)
3064  {
3065  	int ret;
3066  
3067  	ret = bpf_mem_alloc_init(&bpf_global_ma, 0, false);
3068  	bpf_global_ma_set = !ret;
3069  	return ret;
3070  }
3071  late_initcall(bpf_global_ma_init);
3072  #endif
3073  
3074  DEFINE_STATIC_KEY_FALSE(bpf_stats_enabled_key);
3075  EXPORT_SYMBOL(bpf_stats_enabled_key);
3076  
3077  /* All definitions of tracepoints related to BPF. */
3078  #define CREATE_TRACE_POINTS
3079  #include <linux/bpf_trace.h>
3080  
3081  EXPORT_TRACEPOINT_SYMBOL_GPL(xdp_exception);
3082  EXPORT_TRACEPOINT_SYMBOL_GPL(xdp_bulk_tx);
3083