Commit | Line | Data |
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2874c5fd | 1 | // SPDX-License-Identifier: GPL-2.0-or-later |
f5bffecd AS |
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 | * | |
f5bffecd | 16 | * Andi Kleen - Fix a few bad bugs and races. |
4df95ff4 | 17 | * Kris Katterjohn - Added many additional checks in bpf_check_classic() |
f5bffecd | 18 | */ |
738cbe72 | 19 | |
838e9690 | 20 | #include <uapi/linux/btf.h> |
f5bffecd AS |
21 | #include <linux/filter.h> |
22 | #include <linux/skbuff.h> | |
60a3b225 | 23 | #include <linux/vmalloc.h> |
738cbe72 DB |
24 | #include <linux/random.h> |
25 | #include <linux/moduleloader.h> | |
09756af4 | 26 | #include <linux/bpf.h> |
838e9690 | 27 | #include <linux/btf.h> |
39853cc0 | 28 | #include <linux/frame.h> |
74451e66 DB |
29 | #include <linux/rbtree_latch.h> |
30 | #include <linux/kallsyms.h> | |
31 | #include <linux/rcupdate.h> | |
c195651e | 32 | #include <linux/perf_event.h> |
3dec541b | 33 | #include <linux/extable.h> |
3324b584 DB |
34 | #include <asm/unaligned.h> |
35 | ||
f5bffecd AS |
36 | /* Registers */ |
37 | #define BPF_R0 regs[BPF_REG_0] | |
38 | #define BPF_R1 regs[BPF_REG_1] | |
39 | #define BPF_R2 regs[BPF_REG_2] | |
40 | #define BPF_R3 regs[BPF_REG_3] | |
41 | #define BPF_R4 regs[BPF_REG_4] | |
42 | #define BPF_R5 regs[BPF_REG_5] | |
43 | #define BPF_R6 regs[BPF_REG_6] | |
44 | #define BPF_R7 regs[BPF_REG_7] | |
45 | #define BPF_R8 regs[BPF_REG_8] | |
46 | #define BPF_R9 regs[BPF_REG_9] | |
47 | #define BPF_R10 regs[BPF_REG_10] | |
48 | ||
49 | /* Named registers */ | |
50 | #define DST regs[insn->dst_reg] | |
51 | #define SRC regs[insn->src_reg] | |
52 | #define FP regs[BPF_REG_FP] | |
144cd91c | 53 | #define AX regs[BPF_REG_AX] |
f5bffecd AS |
54 | #define ARG1 regs[BPF_REG_ARG1] |
55 | #define CTX regs[BPF_REG_CTX] | |
56 | #define IMM insn->imm | |
57 | ||
58 | /* No hurry in this branch | |
59 | * | |
60 | * Exported for the bpf jit load helper. | |
61 | */ | |
62 | void *bpf_internal_load_pointer_neg_helper(const struct sk_buff *skb, int k, unsigned int size) | |
63 | { | |
64 | u8 *ptr = NULL; | |
65 | ||
66 | if (k >= SKF_NET_OFF) | |
67 | ptr = skb_network_header(skb) + k - SKF_NET_OFF; | |
68 | else if (k >= SKF_LL_OFF) | |
69 | ptr = skb_mac_header(skb) + k - SKF_LL_OFF; | |
3324b584 | 70 | |
f5bffecd AS |
71 | if (ptr >= skb->head && ptr + size <= skb_tail_pointer(skb)) |
72 | return ptr; | |
73 | ||
74 | return NULL; | |
75 | } | |
76 | ||
492ecee8 | 77 | struct bpf_prog *bpf_prog_alloc_no_stats(unsigned int size, gfp_t gfp_extra_flags) |
60a3b225 | 78 | { |
19809c2d | 79 | gfp_t gfp_flags = GFP_KERNEL | __GFP_ZERO | gfp_extra_flags; |
09756af4 | 80 | struct bpf_prog_aux *aux; |
60a3b225 DB |
81 | struct bpf_prog *fp; |
82 | ||
83 | size = round_up(size, PAGE_SIZE); | |
84 | fp = __vmalloc(size, gfp_flags, PAGE_KERNEL); | |
85 | if (fp == NULL) | |
86 | return NULL; | |
87 | ||
09756af4 AS |
88 | aux = kzalloc(sizeof(*aux), GFP_KERNEL | gfp_extra_flags); |
89 | if (aux == NULL) { | |
60a3b225 DB |
90 | vfree(fp); |
91 | return NULL; | |
92 | } | |
93 | ||
94 | fp->pages = size / PAGE_SIZE; | |
09756af4 | 95 | fp->aux = aux; |
e9d8afa9 | 96 | fp->aux->prog = fp; |
60b58afc | 97 | fp->jit_requested = ebpf_jit_enabled(); |
60a3b225 | 98 | |
74451e66 DB |
99 | INIT_LIST_HEAD_RCU(&fp->aux->ksym_lnode); |
100 | ||
60a3b225 DB |
101 | return fp; |
102 | } | |
492ecee8 AS |
103 | |
104 | struct bpf_prog *bpf_prog_alloc(unsigned int size, gfp_t gfp_extra_flags) | |
105 | { | |
106 | gfp_t gfp_flags = GFP_KERNEL | __GFP_ZERO | gfp_extra_flags; | |
107 | struct bpf_prog *prog; | |
4b911304 | 108 | int cpu; |
492ecee8 AS |
109 | |
110 | prog = bpf_prog_alloc_no_stats(size, gfp_extra_flags); | |
111 | if (!prog) | |
112 | return NULL; | |
113 | ||
114 | prog->aux->stats = alloc_percpu_gfp(struct bpf_prog_stats, gfp_flags); | |
115 | if (!prog->aux->stats) { | |
116 | kfree(prog->aux); | |
117 | vfree(prog); | |
118 | return NULL; | |
119 | } | |
120 | ||
4b911304 ED |
121 | for_each_possible_cpu(cpu) { |
122 | struct bpf_prog_stats *pstats; | |
123 | ||
124 | pstats = per_cpu_ptr(prog->aux->stats, cpu); | |
125 | u64_stats_init(&pstats->syncp); | |
126 | } | |
492ecee8 AS |
127 | return prog; |
128 | } | |
60a3b225 DB |
129 | EXPORT_SYMBOL_GPL(bpf_prog_alloc); |
130 | ||
c454a46b MKL |
131 | int bpf_prog_alloc_jited_linfo(struct bpf_prog *prog) |
132 | { | |
133 | if (!prog->aux->nr_linfo || !prog->jit_requested) | |
134 | return 0; | |
135 | ||
136 | prog->aux->jited_linfo = kcalloc(prog->aux->nr_linfo, | |
137 | sizeof(*prog->aux->jited_linfo), | |
138 | GFP_KERNEL | __GFP_NOWARN); | |
139 | if (!prog->aux->jited_linfo) | |
140 | return -ENOMEM; | |
141 | ||
142 | return 0; | |
143 | } | |
144 | ||
145 | void bpf_prog_free_jited_linfo(struct bpf_prog *prog) | |
146 | { | |
147 | kfree(prog->aux->jited_linfo); | |
148 | prog->aux->jited_linfo = NULL; | |
149 | } | |
150 | ||
151 | void bpf_prog_free_unused_jited_linfo(struct bpf_prog *prog) | |
152 | { | |
153 | if (prog->aux->jited_linfo && !prog->aux->jited_linfo[0]) | |
154 | bpf_prog_free_jited_linfo(prog); | |
155 | } | |
156 | ||
157 | /* The jit engine is responsible to provide an array | |
158 | * for insn_off to the jited_off mapping (insn_to_jit_off). | |
159 | * | |
160 | * The idx to this array is the insn_off. Hence, the insn_off | |
161 | * here is relative to the prog itself instead of the main prog. | |
162 | * This array has one entry for each xlated bpf insn. | |
163 | * | |
164 | * jited_off is the byte off to the last byte of the jited insn. | |
165 | * | |
166 | * Hence, with | |
167 | * insn_start: | |
168 | * The first bpf insn off of the prog. The insn off | |
169 | * here is relative to the main prog. | |
170 | * e.g. if prog is a subprog, insn_start > 0 | |
171 | * linfo_idx: | |
172 | * The prog's idx to prog->aux->linfo and jited_linfo | |
173 | * | |
174 | * jited_linfo[linfo_idx] = prog->bpf_func | |
175 | * | |
176 | * For i > linfo_idx, | |
177 | * | |
178 | * jited_linfo[i] = prog->bpf_func + | |
179 | * insn_to_jit_off[linfo[i].insn_off - insn_start - 1] | |
180 | */ | |
181 | void bpf_prog_fill_jited_linfo(struct bpf_prog *prog, | |
182 | const u32 *insn_to_jit_off) | |
183 | { | |
184 | u32 linfo_idx, insn_start, insn_end, nr_linfo, i; | |
185 | const struct bpf_line_info *linfo; | |
186 | void **jited_linfo; | |
187 | ||
188 | if (!prog->aux->jited_linfo) | |
189 | /* Userspace did not provide linfo */ | |
190 | return; | |
191 | ||
192 | linfo_idx = prog->aux->linfo_idx; | |
193 | linfo = &prog->aux->linfo[linfo_idx]; | |
194 | insn_start = linfo[0].insn_off; | |
195 | insn_end = insn_start + prog->len; | |
196 | ||
197 | jited_linfo = &prog->aux->jited_linfo[linfo_idx]; | |
198 | jited_linfo[0] = prog->bpf_func; | |
199 | ||
200 | nr_linfo = prog->aux->nr_linfo - linfo_idx; | |
201 | ||
202 | for (i = 1; i < nr_linfo && linfo[i].insn_off < insn_end; i++) | |
203 | /* The verifier ensures that linfo[i].insn_off is | |
204 | * strictly increasing | |
205 | */ | |
206 | jited_linfo[i] = prog->bpf_func + | |
207 | insn_to_jit_off[linfo[i].insn_off - insn_start - 1]; | |
208 | } | |
209 | ||
210 | void bpf_prog_free_linfo(struct bpf_prog *prog) | |
211 | { | |
212 | bpf_prog_free_jited_linfo(prog); | |
213 | kvfree(prog->aux->linfo); | |
214 | } | |
215 | ||
60a3b225 DB |
216 | struct bpf_prog *bpf_prog_realloc(struct bpf_prog *fp_old, unsigned int size, |
217 | gfp_t gfp_extra_flags) | |
218 | { | |
19809c2d | 219 | gfp_t gfp_flags = GFP_KERNEL | __GFP_ZERO | gfp_extra_flags; |
60a3b225 | 220 | struct bpf_prog *fp; |
5ccb071e DB |
221 | u32 pages, delta; |
222 | int ret; | |
60a3b225 DB |
223 | |
224 | BUG_ON(fp_old == NULL); | |
225 | ||
226 | size = round_up(size, PAGE_SIZE); | |
5ccb071e DB |
227 | pages = size / PAGE_SIZE; |
228 | if (pages <= fp_old->pages) | |
60a3b225 DB |
229 | return fp_old; |
230 | ||
5ccb071e DB |
231 | delta = pages - fp_old->pages; |
232 | ret = __bpf_prog_charge(fp_old->aux->user, delta); | |
233 | if (ret) | |
234 | return NULL; | |
235 | ||
60a3b225 | 236 | fp = __vmalloc(size, gfp_flags, PAGE_KERNEL); |
5ccb071e DB |
237 | if (fp == NULL) { |
238 | __bpf_prog_uncharge(fp_old->aux->user, delta); | |
239 | } else { | |
60a3b225 | 240 | memcpy(fp, fp_old, fp_old->pages * PAGE_SIZE); |
5ccb071e | 241 | fp->pages = pages; |
e9d8afa9 | 242 | fp->aux->prog = fp; |
60a3b225 | 243 | |
09756af4 | 244 | /* We keep fp->aux from fp_old around in the new |
60a3b225 DB |
245 | * reallocated structure. |
246 | */ | |
09756af4 | 247 | fp_old->aux = NULL; |
60a3b225 DB |
248 | __bpf_prog_free(fp_old); |
249 | } | |
250 | ||
251 | return fp; | |
252 | } | |
60a3b225 DB |
253 | |
254 | void __bpf_prog_free(struct bpf_prog *fp) | |
255 | { | |
492ecee8 AS |
256 | if (fp->aux) { |
257 | free_percpu(fp->aux->stats); | |
258 | kfree(fp->aux); | |
259 | } | |
60a3b225 DB |
260 | vfree(fp); |
261 | } | |
60a3b225 | 262 | |
f1f7714e | 263 | int bpf_prog_calc_tag(struct bpf_prog *fp) |
7bd509e3 DB |
264 | { |
265 | const u32 bits_offset = SHA_MESSAGE_BYTES - sizeof(__be64); | |
f1f7714e DB |
266 | u32 raw_size = bpf_prog_tag_scratch_size(fp); |
267 | u32 digest[SHA_DIGEST_WORDS]; | |
aafe6ae9 | 268 | u32 ws[SHA_WORKSPACE_WORDS]; |
7bd509e3 | 269 | u32 i, bsize, psize, blocks; |
aafe6ae9 | 270 | struct bpf_insn *dst; |
7bd509e3 | 271 | bool was_ld_map; |
aafe6ae9 | 272 | u8 *raw, *todo; |
7bd509e3 DB |
273 | __be32 *result; |
274 | __be64 *bits; | |
275 | ||
aafe6ae9 DB |
276 | raw = vmalloc(raw_size); |
277 | if (!raw) | |
278 | return -ENOMEM; | |
279 | ||
f1f7714e | 280 | sha_init(digest); |
7bd509e3 DB |
281 | memset(ws, 0, sizeof(ws)); |
282 | ||
283 | /* We need to take out the map fd for the digest calculation | |
284 | * since they are unstable from user space side. | |
285 | */ | |
aafe6ae9 | 286 | dst = (void *)raw; |
7bd509e3 DB |
287 | for (i = 0, was_ld_map = false; i < fp->len; i++) { |
288 | dst[i] = fp->insnsi[i]; | |
289 | if (!was_ld_map && | |
290 | dst[i].code == (BPF_LD | BPF_IMM | BPF_DW) && | |
d8eca5bb DB |
291 | (dst[i].src_reg == BPF_PSEUDO_MAP_FD || |
292 | dst[i].src_reg == BPF_PSEUDO_MAP_VALUE)) { | |
7bd509e3 DB |
293 | was_ld_map = true; |
294 | dst[i].imm = 0; | |
295 | } else if (was_ld_map && | |
296 | dst[i].code == 0 && | |
297 | dst[i].dst_reg == 0 && | |
298 | dst[i].src_reg == 0 && | |
299 | dst[i].off == 0) { | |
300 | was_ld_map = false; | |
301 | dst[i].imm = 0; | |
302 | } else { | |
303 | was_ld_map = false; | |
304 | } | |
305 | } | |
306 | ||
aafe6ae9 DB |
307 | psize = bpf_prog_insn_size(fp); |
308 | memset(&raw[psize], 0, raw_size - psize); | |
7bd509e3 DB |
309 | raw[psize++] = 0x80; |
310 | ||
311 | bsize = round_up(psize, SHA_MESSAGE_BYTES); | |
312 | blocks = bsize / SHA_MESSAGE_BYTES; | |
aafe6ae9 | 313 | todo = raw; |
7bd509e3 DB |
314 | if (bsize - psize >= sizeof(__be64)) { |
315 | bits = (__be64 *)(todo + bsize - sizeof(__be64)); | |
316 | } else { | |
317 | bits = (__be64 *)(todo + bsize + bits_offset); | |
318 | blocks++; | |
319 | } | |
320 | *bits = cpu_to_be64((psize - 1) << 3); | |
321 | ||
322 | while (blocks--) { | |
f1f7714e | 323 | sha_transform(digest, todo, ws); |
7bd509e3 DB |
324 | todo += SHA_MESSAGE_BYTES; |
325 | } | |
326 | ||
f1f7714e | 327 | result = (__force __be32 *)digest; |
7bd509e3 | 328 | for (i = 0; i < SHA_DIGEST_WORDS; i++) |
f1f7714e DB |
329 | result[i] = cpu_to_be32(digest[i]); |
330 | memcpy(fp->tag, result, sizeof(fp->tag)); | |
aafe6ae9 DB |
331 | |
332 | vfree(raw); | |
333 | return 0; | |
7bd509e3 DB |
334 | } |
335 | ||
2cbd95a5 | 336 | static int bpf_adj_delta_to_imm(struct bpf_insn *insn, u32 pos, s32 end_old, |
af959b18 | 337 | s32 end_new, s32 curr, const bool probe_pass) |
c237ee5e | 338 | { |
050fad7c | 339 | const s64 imm_min = S32_MIN, imm_max = S32_MAX; |
2cbd95a5 | 340 | s32 delta = end_new - end_old; |
050fad7c DB |
341 | s64 imm = insn->imm; |
342 | ||
2cbd95a5 | 343 | if (curr < pos && curr + imm + 1 >= end_old) |
050fad7c | 344 | imm += delta; |
2cbd95a5 | 345 | else if (curr >= end_new && curr + imm + 1 < end_new) |
050fad7c DB |
346 | imm -= delta; |
347 | if (imm < imm_min || imm > imm_max) | |
348 | return -ERANGE; | |
349 | if (!probe_pass) | |
350 | insn->imm = imm; | |
351 | return 0; | |
352 | } | |
353 | ||
2cbd95a5 | 354 | static int bpf_adj_delta_to_off(struct bpf_insn *insn, u32 pos, s32 end_old, |
af959b18 | 355 | s32 end_new, s32 curr, const bool probe_pass) |
050fad7c DB |
356 | { |
357 | const s32 off_min = S16_MIN, off_max = S16_MAX; | |
2cbd95a5 | 358 | s32 delta = end_new - end_old; |
050fad7c DB |
359 | s32 off = insn->off; |
360 | ||
2cbd95a5 | 361 | if (curr < pos && curr + off + 1 >= end_old) |
050fad7c | 362 | off += delta; |
2cbd95a5 | 363 | else if (curr >= end_new && curr + off + 1 < end_new) |
050fad7c DB |
364 | off -= delta; |
365 | if (off < off_min || off > off_max) | |
366 | return -ERANGE; | |
367 | if (!probe_pass) | |
368 | insn->off = off; | |
369 | return 0; | |
370 | } | |
371 | ||
2cbd95a5 JK |
372 | static int bpf_adj_branches(struct bpf_prog *prog, u32 pos, s32 end_old, |
373 | s32 end_new, const bool probe_pass) | |
050fad7c | 374 | { |
2cbd95a5 | 375 | u32 i, insn_cnt = prog->len + (probe_pass ? end_new - end_old : 0); |
c237ee5e | 376 | struct bpf_insn *insn = prog->insnsi; |
050fad7c | 377 | int ret = 0; |
c237ee5e DB |
378 | |
379 | for (i = 0; i < insn_cnt; i++, insn++) { | |
050fad7c DB |
380 | u8 code; |
381 | ||
382 | /* In the probing pass we still operate on the original, | |
383 | * unpatched image in order to check overflows before we | |
384 | * do any other adjustments. Therefore skip the patchlet. | |
385 | */ | |
386 | if (probe_pass && i == pos) { | |
2cbd95a5 JK |
387 | i = end_new; |
388 | insn = prog->insnsi + end_old; | |
050fad7c | 389 | } |
1ea47e01 | 390 | code = insn->code; |
092ed096 JW |
391 | if ((BPF_CLASS(code) != BPF_JMP && |
392 | BPF_CLASS(code) != BPF_JMP32) || | |
050fad7c | 393 | BPF_OP(code) == BPF_EXIT) |
1ea47e01 | 394 | continue; |
050fad7c | 395 | /* Adjust offset of jmps if we cross patch boundaries. */ |
1ea47e01 | 396 | if (BPF_OP(code) == BPF_CALL) { |
050fad7c | 397 | if (insn->src_reg != BPF_PSEUDO_CALL) |
1ea47e01 | 398 | continue; |
2cbd95a5 JK |
399 | ret = bpf_adj_delta_to_imm(insn, pos, end_old, |
400 | end_new, i, probe_pass); | |
1ea47e01 | 401 | } else { |
2cbd95a5 JK |
402 | ret = bpf_adj_delta_to_off(insn, pos, end_old, |
403 | end_new, i, probe_pass); | |
1ea47e01 | 404 | } |
050fad7c DB |
405 | if (ret) |
406 | break; | |
c237ee5e | 407 | } |
050fad7c DB |
408 | |
409 | return ret; | |
c237ee5e DB |
410 | } |
411 | ||
c454a46b MKL |
412 | static void bpf_adj_linfo(struct bpf_prog *prog, u32 off, u32 delta) |
413 | { | |
414 | struct bpf_line_info *linfo; | |
415 | u32 i, nr_linfo; | |
416 | ||
417 | nr_linfo = prog->aux->nr_linfo; | |
418 | if (!nr_linfo || !delta) | |
419 | return; | |
420 | ||
421 | linfo = prog->aux->linfo; | |
422 | ||
423 | for (i = 0; i < nr_linfo; i++) | |
424 | if (off < linfo[i].insn_off) | |
425 | break; | |
426 | ||
427 | /* Push all off < linfo[i].insn_off by delta */ | |
428 | for (; i < nr_linfo; i++) | |
429 | linfo[i].insn_off += delta; | |
430 | } | |
431 | ||
c237ee5e DB |
432 | struct bpf_prog *bpf_patch_insn_single(struct bpf_prog *prog, u32 off, |
433 | const struct bpf_insn *patch, u32 len) | |
434 | { | |
435 | u32 insn_adj_cnt, insn_rest, insn_delta = len - 1; | |
050fad7c | 436 | const u32 cnt_max = S16_MAX; |
c237ee5e | 437 | struct bpf_prog *prog_adj; |
4f73379e | 438 | int err; |
c237ee5e DB |
439 | |
440 | /* Since our patchlet doesn't expand the image, we're done. */ | |
441 | if (insn_delta == 0) { | |
442 | memcpy(prog->insnsi + off, patch, sizeof(*patch)); | |
443 | return prog; | |
444 | } | |
445 | ||
446 | insn_adj_cnt = prog->len + insn_delta; | |
447 | ||
050fad7c DB |
448 | /* Reject anything that would potentially let the insn->off |
449 | * target overflow when we have excessive program expansions. | |
450 | * We need to probe here before we do any reallocation where | |
451 | * we afterwards may not fail anymore. | |
452 | */ | |
453 | if (insn_adj_cnt > cnt_max && | |
4f73379e AS |
454 | (err = bpf_adj_branches(prog, off, off + 1, off + len, true))) |
455 | return ERR_PTR(err); | |
050fad7c | 456 | |
c237ee5e DB |
457 | /* Several new instructions need to be inserted. Make room |
458 | * for them. Likely, there's no need for a new allocation as | |
459 | * last page could have large enough tailroom. | |
460 | */ | |
461 | prog_adj = bpf_prog_realloc(prog, bpf_prog_size(insn_adj_cnt), | |
462 | GFP_USER); | |
463 | if (!prog_adj) | |
4f73379e | 464 | return ERR_PTR(-ENOMEM); |
c237ee5e DB |
465 | |
466 | prog_adj->len = insn_adj_cnt; | |
467 | ||
468 | /* Patching happens in 3 steps: | |
469 | * | |
470 | * 1) Move over tail of insnsi from next instruction onwards, | |
471 | * so we can patch the single target insn with one or more | |
472 | * new ones (patching is always from 1 to n insns, n > 0). | |
473 | * 2) Inject new instructions at the target location. | |
474 | * 3) Adjust branch offsets if necessary. | |
475 | */ | |
476 | insn_rest = insn_adj_cnt - off - len; | |
477 | ||
478 | memmove(prog_adj->insnsi + off + len, prog_adj->insnsi + off + 1, | |
479 | sizeof(*patch) * insn_rest); | |
480 | memcpy(prog_adj->insnsi + off, patch, sizeof(*patch) * len); | |
481 | ||
050fad7c DB |
482 | /* We are guaranteed to not fail at this point, otherwise |
483 | * the ship has sailed to reverse to the original state. An | |
484 | * overflow cannot happen at this point. | |
485 | */ | |
2cbd95a5 | 486 | BUG_ON(bpf_adj_branches(prog_adj, off, off + 1, off + len, false)); |
c237ee5e | 487 | |
c454a46b MKL |
488 | bpf_adj_linfo(prog_adj, off, insn_delta); |
489 | ||
c237ee5e DB |
490 | return prog_adj; |
491 | } | |
492 | ||
52875a04 JK |
493 | int bpf_remove_insns(struct bpf_prog *prog, u32 off, u32 cnt) |
494 | { | |
495 | /* Branch offsets can't overflow when program is shrinking, no need | |
496 | * to call bpf_adj_branches(..., true) here | |
497 | */ | |
498 | memmove(prog->insnsi + off, prog->insnsi + off + cnt, | |
499 | sizeof(struct bpf_insn) * (prog->len - off - cnt)); | |
500 | prog->len -= cnt; | |
501 | ||
502 | return WARN_ON_ONCE(bpf_adj_branches(prog, off, off + cnt, off, false)); | |
503 | } | |
504 | ||
cd7455f1 | 505 | static void bpf_prog_kallsyms_del_subprogs(struct bpf_prog *fp) |
7d1982b4 DB |
506 | { |
507 | int i; | |
508 | ||
509 | for (i = 0; i < fp->aux->func_cnt; i++) | |
510 | bpf_prog_kallsyms_del(fp->aux->func[i]); | |
511 | } | |
512 | ||
513 | void bpf_prog_kallsyms_del_all(struct bpf_prog *fp) | |
514 | { | |
515 | bpf_prog_kallsyms_del_subprogs(fp); | |
516 | bpf_prog_kallsyms_del(fp); | |
517 | } | |
518 | ||
b954d834 | 519 | #ifdef CONFIG_BPF_JIT |
fa9dd599 DB |
520 | /* All BPF JIT sysctl knobs here. */ |
521 | int bpf_jit_enable __read_mostly = IS_BUILTIN(CONFIG_BPF_JIT_ALWAYS_ON); | |
522 | int bpf_jit_harden __read_mostly; | |
523 | int bpf_jit_kallsyms __read_mostly; | |
fdadd049 | 524 | long bpf_jit_limit __read_mostly; |
fa9dd599 | 525 | |
74451e66 DB |
526 | static __always_inline void |
527 | bpf_get_prog_addr_region(const struct bpf_prog *prog, | |
528 | unsigned long *symbol_start, | |
529 | unsigned long *symbol_end) | |
530 | { | |
531 | const struct bpf_binary_header *hdr = bpf_jit_binary_hdr(prog); | |
532 | unsigned long addr = (unsigned long)hdr; | |
533 | ||
534 | WARN_ON_ONCE(!bpf_prog_ebpf_jited(prog)); | |
535 | ||
536 | *symbol_start = addr; | |
537 | *symbol_end = addr + hdr->pages * PAGE_SIZE; | |
538 | } | |
539 | ||
6ee52e2a | 540 | void bpf_get_prog_name(const struct bpf_prog *prog, char *sym) |
74451e66 | 541 | { |
368211fb | 542 | const char *end = sym + KSYM_NAME_LEN; |
838e9690 YS |
543 | const struct btf_type *type; |
544 | const char *func_name; | |
368211fb | 545 | |
74451e66 | 546 | BUILD_BUG_ON(sizeof("bpf_prog_") + |
368211fb MKL |
547 | sizeof(prog->tag) * 2 + |
548 | /* name has been null terminated. | |
549 | * We should need +1 for the '_' preceding | |
550 | * the name. However, the null character | |
551 | * is double counted between the name and the | |
552 | * sizeof("bpf_prog_") above, so we omit | |
553 | * the +1 here. | |
554 | */ | |
555 | sizeof(prog->aux->name) > KSYM_NAME_LEN); | |
74451e66 DB |
556 | |
557 | sym += snprintf(sym, KSYM_NAME_LEN, "bpf_prog_"); | |
558 | sym = bin2hex(sym, prog->tag, sizeof(prog->tag)); | |
838e9690 YS |
559 | |
560 | /* prog->aux->name will be ignored if full btf name is available */ | |
7337224f | 561 | if (prog->aux->func_info_cnt) { |
ba64e7d8 YS |
562 | type = btf_type_by_id(prog->aux->btf, |
563 | prog->aux->func_info[prog->aux->func_idx].type_id); | |
838e9690 YS |
564 | func_name = btf_name_by_offset(prog->aux->btf, type->name_off); |
565 | snprintf(sym, (size_t)(end - sym), "_%s", func_name); | |
566 | return; | |
567 | } | |
568 | ||
368211fb MKL |
569 | if (prog->aux->name[0]) |
570 | snprintf(sym, (size_t)(end - sym), "_%s", prog->aux->name); | |
571 | else | |
572 | *sym = 0; | |
74451e66 DB |
573 | } |
574 | ||
575 | static __always_inline unsigned long | |
576 | bpf_get_prog_addr_start(struct latch_tree_node *n) | |
577 | { | |
578 | unsigned long symbol_start, symbol_end; | |
579 | const struct bpf_prog_aux *aux; | |
580 | ||
581 | aux = container_of(n, struct bpf_prog_aux, ksym_tnode); | |
582 | bpf_get_prog_addr_region(aux->prog, &symbol_start, &symbol_end); | |
583 | ||
584 | return symbol_start; | |
585 | } | |
586 | ||
587 | static __always_inline bool bpf_tree_less(struct latch_tree_node *a, | |
588 | struct latch_tree_node *b) | |
589 | { | |
590 | return bpf_get_prog_addr_start(a) < bpf_get_prog_addr_start(b); | |
591 | } | |
592 | ||
593 | static __always_inline int bpf_tree_comp(void *key, struct latch_tree_node *n) | |
594 | { | |
595 | unsigned long val = (unsigned long)key; | |
596 | unsigned long symbol_start, symbol_end; | |
597 | const struct bpf_prog_aux *aux; | |
598 | ||
599 | aux = container_of(n, struct bpf_prog_aux, ksym_tnode); | |
600 | bpf_get_prog_addr_region(aux->prog, &symbol_start, &symbol_end); | |
601 | ||
602 | if (val < symbol_start) | |
603 | return -1; | |
604 | if (val >= symbol_end) | |
605 | return 1; | |
606 | ||
607 | return 0; | |
608 | } | |
609 | ||
610 | static const struct latch_tree_ops bpf_tree_ops = { | |
611 | .less = bpf_tree_less, | |
612 | .comp = bpf_tree_comp, | |
613 | }; | |
614 | ||
615 | static DEFINE_SPINLOCK(bpf_lock); | |
616 | static LIST_HEAD(bpf_kallsyms); | |
617 | static struct latch_tree_root bpf_tree __cacheline_aligned; | |
618 | ||
74451e66 DB |
619 | static void bpf_prog_ksym_node_add(struct bpf_prog_aux *aux) |
620 | { | |
621 | WARN_ON_ONCE(!list_empty(&aux->ksym_lnode)); | |
622 | list_add_tail_rcu(&aux->ksym_lnode, &bpf_kallsyms); | |
623 | latch_tree_insert(&aux->ksym_tnode, &bpf_tree, &bpf_tree_ops); | |
624 | } | |
625 | ||
626 | static void bpf_prog_ksym_node_del(struct bpf_prog_aux *aux) | |
627 | { | |
628 | if (list_empty(&aux->ksym_lnode)) | |
629 | return; | |
630 | ||
631 | latch_tree_erase(&aux->ksym_tnode, &bpf_tree, &bpf_tree_ops); | |
632 | list_del_rcu(&aux->ksym_lnode); | |
633 | } | |
634 | ||
635 | static bool bpf_prog_kallsyms_candidate(const struct bpf_prog *fp) | |
636 | { | |
637 | return fp->jited && !bpf_prog_was_classic(fp); | |
638 | } | |
639 | ||
640 | static bool bpf_prog_kallsyms_verify_off(const struct bpf_prog *fp) | |
641 | { | |
642 | return list_empty(&fp->aux->ksym_lnode) || | |
643 | fp->aux->ksym_lnode.prev == LIST_POISON2; | |
644 | } | |
645 | ||
646 | void bpf_prog_kallsyms_add(struct bpf_prog *fp) | |
647 | { | |
74451e66 DB |
648 | if (!bpf_prog_kallsyms_candidate(fp) || |
649 | !capable(CAP_SYS_ADMIN)) | |
650 | return; | |
651 | ||
d24f7c7f | 652 | spin_lock_bh(&bpf_lock); |
74451e66 | 653 | bpf_prog_ksym_node_add(fp->aux); |
d24f7c7f | 654 | spin_unlock_bh(&bpf_lock); |
74451e66 DB |
655 | } |
656 | ||
657 | void bpf_prog_kallsyms_del(struct bpf_prog *fp) | |
658 | { | |
74451e66 DB |
659 | if (!bpf_prog_kallsyms_candidate(fp)) |
660 | return; | |
661 | ||
d24f7c7f | 662 | spin_lock_bh(&bpf_lock); |
74451e66 | 663 | bpf_prog_ksym_node_del(fp->aux); |
d24f7c7f | 664 | spin_unlock_bh(&bpf_lock); |
74451e66 DB |
665 | } |
666 | ||
667 | static struct bpf_prog *bpf_prog_kallsyms_find(unsigned long addr) | |
668 | { | |
669 | struct latch_tree_node *n; | |
670 | ||
74451e66 DB |
671 | n = latch_tree_find((void *)addr, &bpf_tree, &bpf_tree_ops); |
672 | return n ? | |
673 | container_of(n, struct bpf_prog_aux, ksym_tnode)->prog : | |
674 | NULL; | |
675 | } | |
676 | ||
677 | const char *__bpf_address_lookup(unsigned long addr, unsigned long *size, | |
678 | unsigned long *off, char *sym) | |
679 | { | |
680 | unsigned long symbol_start, symbol_end; | |
681 | struct bpf_prog *prog; | |
682 | char *ret = NULL; | |
683 | ||
684 | rcu_read_lock(); | |
685 | prog = bpf_prog_kallsyms_find(addr); | |
686 | if (prog) { | |
687 | bpf_get_prog_addr_region(prog, &symbol_start, &symbol_end); | |
688 | bpf_get_prog_name(prog, sym); | |
689 | ||
690 | ret = sym; | |
691 | if (size) | |
692 | *size = symbol_end - symbol_start; | |
693 | if (off) | |
694 | *off = addr - symbol_start; | |
695 | } | |
696 | rcu_read_unlock(); | |
697 | ||
698 | return ret; | |
699 | } | |
700 | ||
701 | bool is_bpf_text_address(unsigned long addr) | |
702 | { | |
703 | bool ret; | |
704 | ||
705 | rcu_read_lock(); | |
706 | ret = bpf_prog_kallsyms_find(addr) != NULL; | |
707 | rcu_read_unlock(); | |
708 | ||
709 | return ret; | |
710 | } | |
711 | ||
3dec541b AS |
712 | const struct exception_table_entry *search_bpf_extables(unsigned long addr) |
713 | { | |
714 | const struct exception_table_entry *e = NULL; | |
715 | struct bpf_prog *prog; | |
716 | ||
717 | rcu_read_lock(); | |
718 | prog = bpf_prog_kallsyms_find(addr); | |
719 | if (!prog) | |
720 | goto out; | |
721 | if (!prog->aux->num_exentries) | |
722 | goto out; | |
723 | ||
724 | e = search_extable(prog->aux->extable, prog->aux->num_exentries, addr); | |
725 | out: | |
726 | rcu_read_unlock(); | |
727 | return e; | |
728 | } | |
729 | ||
74451e66 DB |
730 | int bpf_get_kallsym(unsigned int symnum, unsigned long *value, char *type, |
731 | char *sym) | |
732 | { | |
74451e66 DB |
733 | struct bpf_prog_aux *aux; |
734 | unsigned int it = 0; | |
735 | int ret = -ERANGE; | |
736 | ||
737 | if (!bpf_jit_kallsyms_enabled()) | |
738 | return ret; | |
739 | ||
740 | rcu_read_lock(); | |
741 | list_for_each_entry_rcu(aux, &bpf_kallsyms, ksym_lnode) { | |
742 | if (it++ != symnum) | |
743 | continue; | |
744 | ||
74451e66 DB |
745 | bpf_get_prog_name(aux->prog, sym); |
746 | ||
df073470 | 747 | *value = (unsigned long)aux->prog->bpf_func; |
74451e66 DB |
748 | *type = BPF_SYM_ELF_TYPE; |
749 | ||
750 | ret = 0; | |
751 | break; | |
752 | } | |
753 | rcu_read_unlock(); | |
754 | ||
755 | return ret; | |
756 | } | |
757 | ||
ede95a63 DB |
758 | static atomic_long_t bpf_jit_current; |
759 | ||
fdadd049 DB |
760 | /* Can be overridden by an arch's JIT compiler if it has a custom, |
761 | * dedicated BPF backend memory area, or if neither of the two | |
762 | * below apply. | |
763 | */ | |
764 | u64 __weak bpf_jit_alloc_exec_limit(void) | |
765 | { | |
ede95a63 | 766 | #if defined(MODULES_VADDR) |
fdadd049 DB |
767 | return MODULES_END - MODULES_VADDR; |
768 | #else | |
769 | return VMALLOC_END - VMALLOC_START; | |
770 | #endif | |
771 | } | |
772 | ||
ede95a63 DB |
773 | static int __init bpf_jit_charge_init(void) |
774 | { | |
775 | /* Only used as heuristic here to derive limit. */ | |
fdadd049 DB |
776 | bpf_jit_limit = min_t(u64, round_up(bpf_jit_alloc_exec_limit() >> 2, |
777 | PAGE_SIZE), LONG_MAX); | |
ede95a63 DB |
778 | return 0; |
779 | } | |
780 | pure_initcall(bpf_jit_charge_init); | |
ede95a63 DB |
781 | |
782 | static int bpf_jit_charge_modmem(u32 pages) | |
783 | { | |
784 | if (atomic_long_add_return(pages, &bpf_jit_current) > | |
785 | (bpf_jit_limit >> PAGE_SHIFT)) { | |
786 | if (!capable(CAP_SYS_ADMIN)) { | |
787 | atomic_long_sub(pages, &bpf_jit_current); | |
788 | return -EPERM; | |
789 | } | |
790 | } | |
791 | ||
792 | return 0; | |
793 | } | |
794 | ||
795 | static void bpf_jit_uncharge_modmem(u32 pages) | |
796 | { | |
797 | atomic_long_sub(pages, &bpf_jit_current); | |
798 | } | |
799 | ||
dc002bb6 AB |
800 | void *__weak bpf_jit_alloc_exec(unsigned long size) |
801 | { | |
802 | return module_alloc(size); | |
803 | } | |
804 | ||
805 | void __weak bpf_jit_free_exec(void *addr) | |
806 | { | |
807 | module_memfree(addr); | |
808 | } | |
809 | ||
738cbe72 DB |
810 | struct bpf_binary_header * |
811 | bpf_jit_binary_alloc(unsigned int proglen, u8 **image_ptr, | |
812 | unsigned int alignment, | |
813 | bpf_jit_fill_hole_t bpf_fill_ill_insns) | |
814 | { | |
815 | struct bpf_binary_header *hdr; | |
ede95a63 | 816 | u32 size, hole, start, pages; |
738cbe72 DB |
817 | |
818 | /* Most of BPF filters are really small, but if some of them | |
819 | * fill a page, allow at least 128 extra bytes to insert a | |
820 | * random section of illegal instructions. | |
821 | */ | |
822 | size = round_up(proglen + sizeof(*hdr) + 128, PAGE_SIZE); | |
ede95a63 DB |
823 | pages = size / PAGE_SIZE; |
824 | ||
825 | if (bpf_jit_charge_modmem(pages)) | |
826 | return NULL; | |
dc002bb6 | 827 | hdr = bpf_jit_alloc_exec(size); |
ede95a63 DB |
828 | if (!hdr) { |
829 | bpf_jit_uncharge_modmem(pages); | |
738cbe72 | 830 | return NULL; |
ede95a63 | 831 | } |
738cbe72 DB |
832 | |
833 | /* Fill space with illegal/arch-dep instructions. */ | |
834 | bpf_fill_ill_insns(hdr, size); | |
835 | ||
ede95a63 | 836 | hdr->pages = pages; |
738cbe72 DB |
837 | hole = min_t(unsigned int, size - (proglen + sizeof(*hdr)), |
838 | PAGE_SIZE - sizeof(*hdr)); | |
b7552e1b | 839 | start = (get_random_int() % hole) & ~(alignment - 1); |
738cbe72 DB |
840 | |
841 | /* Leave a random number of instructions before BPF code. */ | |
842 | *image_ptr = &hdr->image[start]; | |
843 | ||
844 | return hdr; | |
845 | } | |
846 | ||
847 | void bpf_jit_binary_free(struct bpf_binary_header *hdr) | |
848 | { | |
ede95a63 DB |
849 | u32 pages = hdr->pages; |
850 | ||
dc002bb6 | 851 | bpf_jit_free_exec(hdr); |
ede95a63 | 852 | bpf_jit_uncharge_modmem(pages); |
738cbe72 | 853 | } |
4f3446bb | 854 | |
74451e66 DB |
855 | /* This symbol is only overridden by archs that have different |
856 | * requirements than the usual eBPF JITs, f.e. when they only | |
857 | * implement cBPF JIT, do not set images read-only, etc. | |
858 | */ | |
859 | void __weak bpf_jit_free(struct bpf_prog *fp) | |
860 | { | |
861 | if (fp->jited) { | |
862 | struct bpf_binary_header *hdr = bpf_jit_binary_hdr(fp); | |
863 | ||
74451e66 DB |
864 | bpf_jit_binary_free(hdr); |
865 | ||
866 | WARN_ON_ONCE(!bpf_prog_kallsyms_verify_off(fp)); | |
867 | } | |
868 | ||
869 | bpf_prog_unlock_free(fp); | |
870 | } | |
871 | ||
e2c95a61 DB |
872 | int bpf_jit_get_func_addr(const struct bpf_prog *prog, |
873 | const struct bpf_insn *insn, bool extra_pass, | |
874 | u64 *func_addr, bool *func_addr_fixed) | |
875 | { | |
876 | s16 off = insn->off; | |
877 | s32 imm = insn->imm; | |
878 | u8 *addr; | |
879 | ||
880 | *func_addr_fixed = insn->src_reg != BPF_PSEUDO_CALL; | |
881 | if (!*func_addr_fixed) { | |
882 | /* Place-holder address till the last pass has collected | |
883 | * all addresses for JITed subprograms in which case we | |
884 | * can pick them up from prog->aux. | |
885 | */ | |
886 | if (!extra_pass) | |
887 | addr = NULL; | |
888 | else if (prog->aux->func && | |
889 | off >= 0 && off < prog->aux->func_cnt) | |
890 | addr = (u8 *)prog->aux->func[off]->bpf_func; | |
891 | else | |
892 | return -EINVAL; | |
893 | } else { | |
894 | /* Address of a BPF helper call. Since part of the core | |
895 | * kernel, it's always at a fixed location. __bpf_call_base | |
896 | * and the helper with imm relative to it are both in core | |
897 | * kernel. | |
898 | */ | |
899 | addr = (u8 *)__bpf_call_base + imm; | |
900 | } | |
901 | ||
902 | *func_addr = (unsigned long)addr; | |
903 | return 0; | |
904 | } | |
905 | ||
4f3446bb DB |
906 | static int bpf_jit_blind_insn(const struct bpf_insn *from, |
907 | const struct bpf_insn *aux, | |
ede7c460 NR |
908 | struct bpf_insn *to_buff, |
909 | bool emit_zext) | |
4f3446bb DB |
910 | { |
911 | struct bpf_insn *to = to_buff; | |
b7552e1b | 912 | u32 imm_rnd = get_random_int(); |
4f3446bb DB |
913 | s16 off; |
914 | ||
915 | BUILD_BUG_ON(BPF_REG_AX + 1 != MAX_BPF_JIT_REG); | |
916 | BUILD_BUG_ON(MAX_BPF_REG + 1 != MAX_BPF_JIT_REG); | |
917 | ||
9b73bfdd DB |
918 | /* Constraints on AX register: |
919 | * | |
920 | * AX register is inaccessible from user space. It is mapped in | |
921 | * all JITs, and used here for constant blinding rewrites. It is | |
922 | * typically "stateless" meaning its contents are only valid within | |
923 | * the executed instruction, but not across several instructions. | |
924 | * There are a few exceptions however which are further detailed | |
925 | * below. | |
926 | * | |
927 | * Constant blinding is only used by JITs, not in the interpreter. | |
928 | * The interpreter uses AX in some occasions as a local temporary | |
929 | * register e.g. in DIV or MOD instructions. | |
930 | * | |
931 | * In restricted circumstances, the verifier can also use the AX | |
932 | * register for rewrites as long as they do not interfere with | |
933 | * the above cases! | |
934 | */ | |
935 | if (from->dst_reg == BPF_REG_AX || from->src_reg == BPF_REG_AX) | |
936 | goto out; | |
937 | ||
4f3446bb DB |
938 | if (from->imm == 0 && |
939 | (from->code == (BPF_ALU | BPF_MOV | BPF_K) || | |
940 | from->code == (BPF_ALU64 | BPF_MOV | BPF_K))) { | |
941 | *to++ = BPF_ALU64_REG(BPF_XOR, from->dst_reg, from->dst_reg); | |
942 | goto out; | |
943 | } | |
944 | ||
945 | switch (from->code) { | |
946 | case BPF_ALU | BPF_ADD | BPF_K: | |
947 | case BPF_ALU | BPF_SUB | BPF_K: | |
948 | case BPF_ALU | BPF_AND | BPF_K: | |
949 | case BPF_ALU | BPF_OR | BPF_K: | |
950 | case BPF_ALU | BPF_XOR | BPF_K: | |
951 | case BPF_ALU | BPF_MUL | BPF_K: | |
952 | case BPF_ALU | BPF_MOV | BPF_K: | |
953 | case BPF_ALU | BPF_DIV | BPF_K: | |
954 | case BPF_ALU | BPF_MOD | BPF_K: | |
955 | *to++ = BPF_ALU32_IMM(BPF_MOV, BPF_REG_AX, imm_rnd ^ from->imm); | |
956 | *to++ = BPF_ALU32_IMM(BPF_XOR, BPF_REG_AX, imm_rnd); | |
957 | *to++ = BPF_ALU32_REG(from->code, from->dst_reg, BPF_REG_AX); | |
958 | break; | |
959 | ||
960 | case BPF_ALU64 | BPF_ADD | BPF_K: | |
961 | case BPF_ALU64 | BPF_SUB | BPF_K: | |
962 | case BPF_ALU64 | BPF_AND | BPF_K: | |
963 | case BPF_ALU64 | BPF_OR | BPF_K: | |
964 | case BPF_ALU64 | BPF_XOR | BPF_K: | |
965 | case BPF_ALU64 | BPF_MUL | BPF_K: | |
966 | case BPF_ALU64 | BPF_MOV | BPF_K: | |
967 | case BPF_ALU64 | BPF_DIV | BPF_K: | |
968 | case BPF_ALU64 | BPF_MOD | BPF_K: | |
969 | *to++ = BPF_ALU64_IMM(BPF_MOV, BPF_REG_AX, imm_rnd ^ from->imm); | |
970 | *to++ = BPF_ALU64_IMM(BPF_XOR, BPF_REG_AX, imm_rnd); | |
971 | *to++ = BPF_ALU64_REG(from->code, from->dst_reg, BPF_REG_AX); | |
972 | break; | |
973 | ||
974 | case BPF_JMP | BPF_JEQ | BPF_K: | |
975 | case BPF_JMP | BPF_JNE | BPF_K: | |
976 | case BPF_JMP | BPF_JGT | BPF_K: | |
92b31a9a | 977 | case BPF_JMP | BPF_JLT | BPF_K: |
4f3446bb | 978 | case BPF_JMP | BPF_JGE | BPF_K: |
92b31a9a | 979 | case BPF_JMP | BPF_JLE | BPF_K: |
4f3446bb | 980 | case BPF_JMP | BPF_JSGT | BPF_K: |
92b31a9a | 981 | case BPF_JMP | BPF_JSLT | BPF_K: |
4f3446bb | 982 | case BPF_JMP | BPF_JSGE | BPF_K: |
92b31a9a | 983 | case BPF_JMP | BPF_JSLE | BPF_K: |
4f3446bb DB |
984 | case BPF_JMP | BPF_JSET | BPF_K: |
985 | /* Accommodate for extra offset in case of a backjump. */ | |
986 | off = from->off; | |
987 | if (off < 0) | |
988 | off -= 2; | |
989 | *to++ = BPF_ALU64_IMM(BPF_MOV, BPF_REG_AX, imm_rnd ^ from->imm); | |
990 | *to++ = BPF_ALU64_IMM(BPF_XOR, BPF_REG_AX, imm_rnd); | |
991 | *to++ = BPF_JMP_REG(from->code, from->dst_reg, BPF_REG_AX, off); | |
992 | break; | |
993 | ||
a7b76c88 JW |
994 | case BPF_JMP32 | BPF_JEQ | BPF_K: |
995 | case BPF_JMP32 | BPF_JNE | BPF_K: | |
996 | case BPF_JMP32 | BPF_JGT | BPF_K: | |
997 | case BPF_JMP32 | BPF_JLT | BPF_K: | |
998 | case BPF_JMP32 | BPF_JGE | BPF_K: | |
999 | case BPF_JMP32 | BPF_JLE | BPF_K: | |
1000 | case BPF_JMP32 | BPF_JSGT | BPF_K: | |
1001 | case BPF_JMP32 | BPF_JSLT | BPF_K: | |
1002 | case BPF_JMP32 | BPF_JSGE | BPF_K: | |
1003 | case BPF_JMP32 | BPF_JSLE | BPF_K: | |
1004 | case BPF_JMP32 | BPF_JSET | BPF_K: | |
1005 | /* Accommodate for extra offset in case of a backjump. */ | |
1006 | off = from->off; | |
1007 | if (off < 0) | |
1008 | off -= 2; | |
1009 | *to++ = BPF_ALU32_IMM(BPF_MOV, BPF_REG_AX, imm_rnd ^ from->imm); | |
1010 | *to++ = BPF_ALU32_IMM(BPF_XOR, BPF_REG_AX, imm_rnd); | |
1011 | *to++ = BPF_JMP32_REG(from->code, from->dst_reg, BPF_REG_AX, | |
1012 | off); | |
1013 | break; | |
1014 | ||
4f3446bb DB |
1015 | case BPF_LD | BPF_IMM | BPF_DW: |
1016 | *to++ = BPF_ALU64_IMM(BPF_MOV, BPF_REG_AX, imm_rnd ^ aux[1].imm); | |
1017 | *to++ = BPF_ALU64_IMM(BPF_XOR, BPF_REG_AX, imm_rnd); | |
1018 | *to++ = BPF_ALU64_IMM(BPF_LSH, BPF_REG_AX, 32); | |
1019 | *to++ = BPF_ALU64_REG(BPF_MOV, aux[0].dst_reg, BPF_REG_AX); | |
1020 | break; | |
1021 | case 0: /* Part 2 of BPF_LD | BPF_IMM | BPF_DW. */ | |
1022 | *to++ = BPF_ALU32_IMM(BPF_MOV, BPF_REG_AX, imm_rnd ^ aux[0].imm); | |
1023 | *to++ = BPF_ALU32_IMM(BPF_XOR, BPF_REG_AX, imm_rnd); | |
ede7c460 NR |
1024 | if (emit_zext) |
1025 | *to++ = BPF_ZEXT_REG(BPF_REG_AX); | |
4f3446bb DB |
1026 | *to++ = BPF_ALU64_REG(BPF_OR, aux[0].dst_reg, BPF_REG_AX); |
1027 | break; | |
1028 | ||
1029 | case BPF_ST | BPF_MEM | BPF_DW: | |
1030 | case BPF_ST | BPF_MEM | BPF_W: | |
1031 | case BPF_ST | BPF_MEM | BPF_H: | |
1032 | case BPF_ST | BPF_MEM | BPF_B: | |
1033 | *to++ = BPF_ALU64_IMM(BPF_MOV, BPF_REG_AX, imm_rnd ^ from->imm); | |
1034 | *to++ = BPF_ALU64_IMM(BPF_XOR, BPF_REG_AX, imm_rnd); | |
1035 | *to++ = BPF_STX_MEM(from->code, from->dst_reg, BPF_REG_AX, from->off); | |
1036 | break; | |
1037 | } | |
1038 | out: | |
1039 | return to - to_buff; | |
1040 | } | |
1041 | ||
1042 | static struct bpf_prog *bpf_prog_clone_create(struct bpf_prog *fp_other, | |
1043 | gfp_t gfp_extra_flags) | |
1044 | { | |
19809c2d | 1045 | gfp_t gfp_flags = GFP_KERNEL | __GFP_ZERO | gfp_extra_flags; |
4f3446bb DB |
1046 | struct bpf_prog *fp; |
1047 | ||
1048 | fp = __vmalloc(fp_other->pages * PAGE_SIZE, gfp_flags, PAGE_KERNEL); | |
1049 | if (fp != NULL) { | |
4f3446bb DB |
1050 | /* aux->prog still points to the fp_other one, so |
1051 | * when promoting the clone to the real program, | |
1052 | * this still needs to be adapted. | |
1053 | */ | |
1054 | memcpy(fp, fp_other, fp_other->pages * PAGE_SIZE); | |
1055 | } | |
1056 | ||
1057 | return fp; | |
1058 | } | |
1059 | ||
1060 | static void bpf_prog_clone_free(struct bpf_prog *fp) | |
1061 | { | |
1062 | /* aux was stolen by the other clone, so we cannot free | |
1063 | * it from this path! It will be freed eventually by the | |
1064 | * other program on release. | |
1065 | * | |
1066 | * At this point, we don't need a deferred release since | |
1067 | * clone is guaranteed to not be locked. | |
1068 | */ | |
1069 | fp->aux = NULL; | |
1070 | __bpf_prog_free(fp); | |
1071 | } | |
1072 | ||
1073 | void bpf_jit_prog_release_other(struct bpf_prog *fp, struct bpf_prog *fp_other) | |
1074 | { | |
1075 | /* We have to repoint aux->prog to self, as we don't | |
1076 | * know whether fp here is the clone or the original. | |
1077 | */ | |
1078 | fp->aux->prog = fp; | |
1079 | bpf_prog_clone_free(fp_other); | |
1080 | } | |
1081 | ||
1082 | struct bpf_prog *bpf_jit_blind_constants(struct bpf_prog *prog) | |
1083 | { | |
1084 | struct bpf_insn insn_buff[16], aux[2]; | |
1085 | struct bpf_prog *clone, *tmp; | |
1086 | int insn_delta, insn_cnt; | |
1087 | struct bpf_insn *insn; | |
1088 | int i, rewritten; | |
1089 | ||
1c2a088a | 1090 | if (!bpf_jit_blinding_enabled(prog) || prog->blinded) |
4f3446bb DB |
1091 | return prog; |
1092 | ||
1093 | clone = bpf_prog_clone_create(prog, GFP_USER); | |
1094 | if (!clone) | |
1095 | return ERR_PTR(-ENOMEM); | |
1096 | ||
1097 | insn_cnt = clone->len; | |
1098 | insn = clone->insnsi; | |
1099 | ||
1100 | for (i = 0; i < insn_cnt; i++, insn++) { | |
1101 | /* We temporarily need to hold the original ld64 insn | |
1102 | * so that we can still access the first part in the | |
1103 | * second blinding run. | |
1104 | */ | |
1105 | if (insn[0].code == (BPF_LD | BPF_IMM | BPF_DW) && | |
1106 | insn[1].code == 0) | |
1107 | memcpy(aux, insn, sizeof(aux)); | |
1108 | ||
ede7c460 NR |
1109 | rewritten = bpf_jit_blind_insn(insn, aux, insn_buff, |
1110 | clone->aux->verifier_zext); | |
4f3446bb DB |
1111 | if (!rewritten) |
1112 | continue; | |
1113 | ||
1114 | tmp = bpf_patch_insn_single(clone, i, insn_buff, rewritten); | |
4f73379e | 1115 | if (IS_ERR(tmp)) { |
4f3446bb DB |
1116 | /* Patching may have repointed aux->prog during |
1117 | * realloc from the original one, so we need to | |
1118 | * fix it up here on error. | |
1119 | */ | |
1120 | bpf_jit_prog_release_other(prog, clone); | |
4f73379e | 1121 | return tmp; |
4f3446bb DB |
1122 | } |
1123 | ||
1124 | clone = tmp; | |
1125 | insn_delta = rewritten - 1; | |
1126 | ||
1127 | /* Walk new program and skip insns we just inserted. */ | |
1128 | insn = clone->insnsi + i + insn_delta; | |
1129 | insn_cnt += insn_delta; | |
1130 | i += insn_delta; | |
1131 | } | |
1132 | ||
1c2a088a | 1133 | clone->blinded = 1; |
4f3446bb DB |
1134 | return clone; |
1135 | } | |
b954d834 | 1136 | #endif /* CONFIG_BPF_JIT */ |
738cbe72 | 1137 | |
f5bffecd AS |
1138 | /* Base function for offset calculation. Needs to go into .text section, |
1139 | * therefore keeping it non-static as well; will also be used by JITs | |
7105e828 DB |
1140 | * anyway later on, so do not let the compiler omit it. This also needs |
1141 | * to go into kallsyms for correlation from e.g. bpftool, so naming | |
1142 | * must not change. | |
f5bffecd AS |
1143 | */ |
1144 | noinline u64 __bpf_call_base(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5) | |
1145 | { | |
1146 | return 0; | |
1147 | } | |
4d9c5c53 | 1148 | EXPORT_SYMBOL_GPL(__bpf_call_base); |
f5bffecd | 1149 | |
5e581dad DB |
1150 | /* All UAPI available opcodes. */ |
1151 | #define BPF_INSN_MAP(INSN_2, INSN_3) \ | |
1152 | /* 32 bit ALU operations. */ \ | |
1153 | /* Register based. */ \ | |
2dc6b100 JW |
1154 | INSN_3(ALU, ADD, X), \ |
1155 | INSN_3(ALU, SUB, X), \ | |
1156 | INSN_3(ALU, AND, X), \ | |
1157 | INSN_3(ALU, OR, X), \ | |
1158 | INSN_3(ALU, LSH, X), \ | |
1159 | INSN_3(ALU, RSH, X), \ | |
1160 | INSN_3(ALU, XOR, X), \ | |
1161 | INSN_3(ALU, MUL, X), \ | |
1162 | INSN_3(ALU, MOV, X), \ | |
1163 | INSN_3(ALU, ARSH, X), \ | |
1164 | INSN_3(ALU, DIV, X), \ | |
1165 | INSN_3(ALU, MOD, X), \ | |
5e581dad DB |
1166 | INSN_2(ALU, NEG), \ |
1167 | INSN_3(ALU, END, TO_BE), \ | |
1168 | INSN_3(ALU, END, TO_LE), \ | |
1169 | /* Immediate based. */ \ | |
2dc6b100 JW |
1170 | INSN_3(ALU, ADD, K), \ |
1171 | INSN_3(ALU, SUB, K), \ | |
1172 | INSN_3(ALU, AND, K), \ | |
1173 | INSN_3(ALU, OR, K), \ | |
1174 | INSN_3(ALU, LSH, K), \ | |
1175 | INSN_3(ALU, RSH, K), \ | |
1176 | INSN_3(ALU, XOR, K), \ | |
1177 | INSN_3(ALU, MUL, K), \ | |
1178 | INSN_3(ALU, MOV, K), \ | |
1179 | INSN_3(ALU, ARSH, K), \ | |
1180 | INSN_3(ALU, DIV, K), \ | |
1181 | INSN_3(ALU, MOD, K), \ | |
5e581dad DB |
1182 | /* 64 bit ALU operations. */ \ |
1183 | /* Register based. */ \ | |
1184 | INSN_3(ALU64, ADD, X), \ | |
1185 | INSN_3(ALU64, SUB, X), \ | |
1186 | INSN_3(ALU64, AND, X), \ | |
1187 | INSN_3(ALU64, OR, X), \ | |
1188 | INSN_3(ALU64, LSH, X), \ | |
1189 | INSN_3(ALU64, RSH, X), \ | |
1190 | INSN_3(ALU64, XOR, X), \ | |
1191 | INSN_3(ALU64, MUL, X), \ | |
1192 | INSN_3(ALU64, MOV, X), \ | |
1193 | INSN_3(ALU64, ARSH, X), \ | |
1194 | INSN_3(ALU64, DIV, X), \ | |
1195 | INSN_3(ALU64, MOD, X), \ | |
1196 | INSN_2(ALU64, NEG), \ | |
1197 | /* Immediate based. */ \ | |
1198 | INSN_3(ALU64, ADD, K), \ | |
1199 | INSN_3(ALU64, SUB, K), \ | |
1200 | INSN_3(ALU64, AND, K), \ | |
1201 | INSN_3(ALU64, OR, K), \ | |
1202 | INSN_3(ALU64, LSH, K), \ | |
1203 | INSN_3(ALU64, RSH, K), \ | |
1204 | INSN_3(ALU64, XOR, K), \ | |
1205 | INSN_3(ALU64, MUL, K), \ | |
1206 | INSN_3(ALU64, MOV, K), \ | |
1207 | INSN_3(ALU64, ARSH, K), \ | |
1208 | INSN_3(ALU64, DIV, K), \ | |
1209 | INSN_3(ALU64, MOD, K), \ | |
1210 | /* Call instruction. */ \ | |
1211 | INSN_2(JMP, CALL), \ | |
1212 | /* Exit instruction. */ \ | |
1213 | INSN_2(JMP, EXIT), \ | |
503a8865 JW |
1214 | /* 32-bit Jump instructions. */ \ |
1215 | /* Register based. */ \ | |
1216 | INSN_3(JMP32, JEQ, X), \ | |
1217 | INSN_3(JMP32, JNE, X), \ | |
1218 | INSN_3(JMP32, JGT, X), \ | |
1219 | INSN_3(JMP32, JLT, X), \ | |
1220 | INSN_3(JMP32, JGE, X), \ | |
1221 | INSN_3(JMP32, JLE, X), \ | |
1222 | INSN_3(JMP32, JSGT, X), \ | |
1223 | INSN_3(JMP32, JSLT, X), \ | |
1224 | INSN_3(JMP32, JSGE, X), \ | |
1225 | INSN_3(JMP32, JSLE, X), \ | |
1226 | INSN_3(JMP32, JSET, X), \ | |
1227 | /* Immediate based. */ \ | |
1228 | INSN_3(JMP32, JEQ, K), \ | |
1229 | INSN_3(JMP32, JNE, K), \ | |
1230 | INSN_3(JMP32, JGT, K), \ | |
1231 | INSN_3(JMP32, JLT, K), \ | |
1232 | INSN_3(JMP32, JGE, K), \ | |
1233 | INSN_3(JMP32, JLE, K), \ | |
1234 | INSN_3(JMP32, JSGT, K), \ | |
1235 | INSN_3(JMP32, JSLT, K), \ | |
1236 | INSN_3(JMP32, JSGE, K), \ | |
1237 | INSN_3(JMP32, JSLE, K), \ | |
1238 | INSN_3(JMP32, JSET, K), \ | |
5e581dad DB |
1239 | /* Jump instructions. */ \ |
1240 | /* Register based. */ \ | |
1241 | INSN_3(JMP, JEQ, X), \ | |
1242 | INSN_3(JMP, JNE, X), \ | |
1243 | INSN_3(JMP, JGT, X), \ | |
1244 | INSN_3(JMP, JLT, X), \ | |
1245 | INSN_3(JMP, JGE, X), \ | |
1246 | INSN_3(JMP, JLE, X), \ | |
1247 | INSN_3(JMP, JSGT, X), \ | |
1248 | INSN_3(JMP, JSLT, X), \ | |
1249 | INSN_3(JMP, JSGE, X), \ | |
1250 | INSN_3(JMP, JSLE, X), \ | |
1251 | INSN_3(JMP, JSET, X), \ | |
1252 | /* Immediate based. */ \ | |
1253 | INSN_3(JMP, JEQ, K), \ | |
1254 | INSN_3(JMP, JNE, K), \ | |
1255 | INSN_3(JMP, JGT, K), \ | |
1256 | INSN_3(JMP, JLT, K), \ | |
1257 | INSN_3(JMP, JGE, K), \ | |
1258 | INSN_3(JMP, JLE, K), \ | |
1259 | INSN_3(JMP, JSGT, K), \ | |
1260 | INSN_3(JMP, JSLT, K), \ | |
1261 | INSN_3(JMP, JSGE, K), \ | |
1262 | INSN_3(JMP, JSLE, K), \ | |
1263 | INSN_3(JMP, JSET, K), \ | |
1264 | INSN_2(JMP, JA), \ | |
1265 | /* Store instructions. */ \ | |
1266 | /* Register based. */ \ | |
1267 | INSN_3(STX, MEM, B), \ | |
1268 | INSN_3(STX, MEM, H), \ | |
1269 | INSN_3(STX, MEM, W), \ | |
1270 | INSN_3(STX, MEM, DW), \ | |
1271 | INSN_3(STX, XADD, W), \ | |
1272 | INSN_3(STX, XADD, DW), \ | |
1273 | /* Immediate based. */ \ | |
1274 | INSN_3(ST, MEM, B), \ | |
1275 | INSN_3(ST, MEM, H), \ | |
1276 | INSN_3(ST, MEM, W), \ | |
1277 | INSN_3(ST, MEM, DW), \ | |
1278 | /* Load instructions. */ \ | |
1279 | /* Register based. */ \ | |
1280 | INSN_3(LDX, MEM, B), \ | |
1281 | INSN_3(LDX, MEM, H), \ | |
1282 | INSN_3(LDX, MEM, W), \ | |
1283 | INSN_3(LDX, MEM, DW), \ | |
1284 | /* Immediate based. */ \ | |
e0cea7ce | 1285 | INSN_3(LD, IMM, DW) |
5e581dad DB |
1286 | |
1287 | bool bpf_opcode_in_insntable(u8 code) | |
1288 | { | |
1289 | #define BPF_INSN_2_TBL(x, y) [BPF_##x | BPF_##y] = true | |
1290 | #define BPF_INSN_3_TBL(x, y, z) [BPF_##x | BPF_##y | BPF_##z] = true | |
1291 | static const bool public_insntable[256] = { | |
1292 | [0 ... 255] = false, | |
1293 | /* Now overwrite non-defaults ... */ | |
1294 | BPF_INSN_MAP(BPF_INSN_2_TBL, BPF_INSN_3_TBL), | |
e0cea7ce DB |
1295 | /* UAPI exposed, but rewritten opcodes. cBPF carry-over. */ |
1296 | [BPF_LD | BPF_ABS | BPF_B] = true, | |
1297 | [BPF_LD | BPF_ABS | BPF_H] = true, | |
1298 | [BPF_LD | BPF_ABS | BPF_W] = true, | |
1299 | [BPF_LD | BPF_IND | BPF_B] = true, | |
1300 | [BPF_LD | BPF_IND | BPF_H] = true, | |
1301 | [BPF_LD | BPF_IND | BPF_W] = true, | |
5e581dad DB |
1302 | }; |
1303 | #undef BPF_INSN_3_TBL | |
1304 | #undef BPF_INSN_2_TBL | |
1305 | return public_insntable[code]; | |
1306 | } | |
1307 | ||
290af866 | 1308 | #ifndef CONFIG_BPF_JIT_ALWAYS_ON |
6e07a634 | 1309 | u64 __weak bpf_probe_read_kernel(void *dst, u32 size, const void *unsafe_ptr) |
2a02759e AS |
1310 | { |
1311 | memset(dst, 0, size); | |
1312 | return -EFAULT; | |
1313 | } | |
6e07a634 | 1314 | |
f5bffecd | 1315 | /** |
7ae457c1 | 1316 | * __bpf_prog_run - run eBPF program on a given context |
de1da68d | 1317 | * @regs: is the array of MAX_BPF_EXT_REG eBPF pseudo-registers |
7ae457c1 | 1318 | * @insn: is the array of eBPF instructions |
de1da68d | 1319 | * @stack: is the eBPF storage stack |
f5bffecd | 1320 | * |
7ae457c1 | 1321 | * Decode and execute eBPF instructions. |
f5bffecd | 1322 | */ |
3193c083 | 1323 | static u64 __no_fgcse ___bpf_prog_run(u64 *regs, const struct bpf_insn *insn, u64 *stack) |
f5bffecd | 1324 | { |
5e581dad DB |
1325 | #define BPF_INSN_2_LBL(x, y) [BPF_##x | BPF_##y] = &&x##_##y |
1326 | #define BPF_INSN_3_LBL(x, y, z) [BPF_##x | BPF_##y | BPF_##z] = &&x##_##y##_##z | |
e55a7325 | 1327 | static const void * const jumptable[256] __annotate_jump_table = { |
f5bffecd AS |
1328 | [0 ... 255] = &&default_label, |
1329 | /* Now overwrite non-defaults ... */ | |
5e581dad DB |
1330 | BPF_INSN_MAP(BPF_INSN_2_LBL, BPF_INSN_3_LBL), |
1331 | /* Non-UAPI available opcodes. */ | |
1ea47e01 | 1332 | [BPF_JMP | BPF_CALL_ARGS] = &&JMP_CALL_ARGS, |
71189fa9 | 1333 | [BPF_JMP | BPF_TAIL_CALL] = &&JMP_TAIL_CALL, |
2a02759e AS |
1334 | [BPF_LDX | BPF_PROBE_MEM | BPF_B] = &&LDX_PROBE_MEM_B, |
1335 | [BPF_LDX | BPF_PROBE_MEM | BPF_H] = &&LDX_PROBE_MEM_H, | |
1336 | [BPF_LDX | BPF_PROBE_MEM | BPF_W] = &&LDX_PROBE_MEM_W, | |
1337 | [BPF_LDX | BPF_PROBE_MEM | BPF_DW] = &&LDX_PROBE_MEM_DW, | |
f5bffecd | 1338 | }; |
5e581dad DB |
1339 | #undef BPF_INSN_3_LBL |
1340 | #undef BPF_INSN_2_LBL | |
04fd61ab | 1341 | u32 tail_call_cnt = 0; |
f5bffecd AS |
1342 | |
1343 | #define CONT ({ insn++; goto select_insn; }) | |
1344 | #define CONT_JMP ({ insn++; goto select_insn; }) | |
1345 | ||
f5bffecd AS |
1346 | select_insn: |
1347 | goto *jumptable[insn->code]; | |
1348 | ||
1349 | /* ALU */ | |
1350 | #define ALU(OPCODE, OP) \ | |
1351 | ALU64_##OPCODE##_X: \ | |
1352 | DST = DST OP SRC; \ | |
1353 | CONT; \ | |
1354 | ALU_##OPCODE##_X: \ | |
1355 | DST = (u32) DST OP (u32) SRC; \ | |
1356 | CONT; \ | |
1357 | ALU64_##OPCODE##_K: \ | |
1358 | DST = DST OP IMM; \ | |
1359 | CONT; \ | |
1360 | ALU_##OPCODE##_K: \ | |
1361 | DST = (u32) DST OP (u32) IMM; \ | |
1362 | CONT; | |
1363 | ||
1364 | ALU(ADD, +) | |
1365 | ALU(SUB, -) | |
1366 | ALU(AND, &) | |
1367 | ALU(OR, |) | |
1368 | ALU(LSH, <<) | |
1369 | ALU(RSH, >>) | |
1370 | ALU(XOR, ^) | |
1371 | ALU(MUL, *) | |
1372 | #undef ALU | |
1373 | ALU_NEG: | |
1374 | DST = (u32) -DST; | |
1375 | CONT; | |
1376 | ALU64_NEG: | |
1377 | DST = -DST; | |
1378 | CONT; | |
1379 | ALU_MOV_X: | |
1380 | DST = (u32) SRC; | |
1381 | CONT; | |
1382 | ALU_MOV_K: | |
1383 | DST = (u32) IMM; | |
1384 | CONT; | |
1385 | ALU64_MOV_X: | |
1386 | DST = SRC; | |
1387 | CONT; | |
1388 | ALU64_MOV_K: | |
1389 | DST = IMM; | |
1390 | CONT; | |
02ab695b AS |
1391 | LD_IMM_DW: |
1392 | DST = (u64) (u32) insn[0].imm | ((u64) (u32) insn[1].imm) << 32; | |
1393 | insn++; | |
1394 | CONT; | |
2dc6b100 | 1395 | ALU_ARSH_X: |
75672dda | 1396 | DST = (u64) (u32) (((s32) DST) >> SRC); |
2dc6b100 JW |
1397 | CONT; |
1398 | ALU_ARSH_K: | |
75672dda | 1399 | DST = (u64) (u32) (((s32) DST) >> IMM); |
2dc6b100 | 1400 | CONT; |
f5bffecd AS |
1401 | ALU64_ARSH_X: |
1402 | (*(s64 *) &DST) >>= SRC; | |
1403 | CONT; | |
1404 | ALU64_ARSH_K: | |
1405 | (*(s64 *) &DST) >>= IMM; | |
1406 | CONT; | |
1407 | ALU64_MOD_X: | |
144cd91c DB |
1408 | div64_u64_rem(DST, SRC, &AX); |
1409 | DST = AX; | |
f5bffecd AS |
1410 | CONT; |
1411 | ALU_MOD_X: | |
144cd91c DB |
1412 | AX = (u32) DST; |
1413 | DST = do_div(AX, (u32) SRC); | |
f5bffecd AS |
1414 | CONT; |
1415 | ALU64_MOD_K: | |
144cd91c DB |
1416 | div64_u64_rem(DST, IMM, &AX); |
1417 | DST = AX; | |
f5bffecd AS |
1418 | CONT; |
1419 | ALU_MOD_K: | |
144cd91c DB |
1420 | AX = (u32) DST; |
1421 | DST = do_div(AX, (u32) IMM); | |
f5bffecd AS |
1422 | CONT; |
1423 | ALU64_DIV_X: | |
876a7ae6 | 1424 | DST = div64_u64(DST, SRC); |
f5bffecd AS |
1425 | CONT; |
1426 | ALU_DIV_X: | |
144cd91c DB |
1427 | AX = (u32) DST; |
1428 | do_div(AX, (u32) SRC); | |
1429 | DST = (u32) AX; | |
f5bffecd AS |
1430 | CONT; |
1431 | ALU64_DIV_K: | |
876a7ae6 | 1432 | DST = div64_u64(DST, IMM); |
f5bffecd AS |
1433 | CONT; |
1434 | ALU_DIV_K: | |
144cd91c DB |
1435 | AX = (u32) DST; |
1436 | do_div(AX, (u32) IMM); | |
1437 | DST = (u32) AX; | |
f5bffecd AS |
1438 | CONT; |
1439 | ALU_END_TO_BE: | |
1440 | switch (IMM) { | |
1441 | case 16: | |
1442 | DST = (__force u16) cpu_to_be16(DST); | |
1443 | break; | |
1444 | case 32: | |
1445 | DST = (__force u32) cpu_to_be32(DST); | |
1446 | break; | |
1447 | case 64: | |
1448 | DST = (__force u64) cpu_to_be64(DST); | |
1449 | break; | |
1450 | } | |
1451 | CONT; | |
1452 | ALU_END_TO_LE: | |
1453 | switch (IMM) { | |
1454 | case 16: | |
1455 | DST = (__force u16) cpu_to_le16(DST); | |
1456 | break; | |
1457 | case 32: | |
1458 | DST = (__force u32) cpu_to_le32(DST); | |
1459 | break; | |
1460 | case 64: | |
1461 | DST = (__force u64) cpu_to_le64(DST); | |
1462 | break; | |
1463 | } | |
1464 | CONT; | |
1465 | ||
1466 | /* CALL */ | |
1467 | JMP_CALL: | |
1468 | /* Function call scratches BPF_R1-BPF_R5 registers, | |
1469 | * preserves BPF_R6-BPF_R9, and stores return value | |
1470 | * into BPF_R0. | |
1471 | */ | |
1472 | BPF_R0 = (__bpf_call_base + insn->imm)(BPF_R1, BPF_R2, BPF_R3, | |
1473 | BPF_R4, BPF_R5); | |
1474 | CONT; | |
1475 | ||
1ea47e01 AS |
1476 | JMP_CALL_ARGS: |
1477 | BPF_R0 = (__bpf_call_base_args + insn->imm)(BPF_R1, BPF_R2, | |
1478 | BPF_R3, BPF_R4, | |
1479 | BPF_R5, | |
1480 | insn + insn->off + 1); | |
1481 | CONT; | |
1482 | ||
04fd61ab AS |
1483 | JMP_TAIL_CALL: { |
1484 | struct bpf_map *map = (struct bpf_map *) (unsigned long) BPF_R2; | |
1485 | struct bpf_array *array = container_of(map, struct bpf_array, map); | |
1486 | struct bpf_prog *prog; | |
90caccdd | 1487 | u32 index = BPF_R3; |
04fd61ab AS |
1488 | |
1489 | if (unlikely(index >= array->map.max_entries)) | |
1490 | goto out; | |
04fd61ab AS |
1491 | if (unlikely(tail_call_cnt > MAX_TAIL_CALL_CNT)) |
1492 | goto out; | |
1493 | ||
1494 | tail_call_cnt++; | |
1495 | ||
2a36f0b9 | 1496 | prog = READ_ONCE(array->ptrs[index]); |
1ca1cc98 | 1497 | if (!prog) |
04fd61ab AS |
1498 | goto out; |
1499 | ||
c4675f93 DB |
1500 | /* ARG1 at this point is guaranteed to point to CTX from |
1501 | * the verifier side due to the fact that the tail call is | |
1502 | * handeled like a helper, that is, bpf_tail_call_proto, | |
1503 | * where arg1_type is ARG_PTR_TO_CTX. | |
1504 | */ | |
04fd61ab AS |
1505 | insn = prog->insnsi; |
1506 | goto select_insn; | |
1507 | out: | |
1508 | CONT; | |
1509 | } | |
f5bffecd AS |
1510 | JMP_JA: |
1511 | insn += insn->off; | |
1512 | CONT; | |
f5bffecd AS |
1513 | JMP_EXIT: |
1514 | return BPF_R0; | |
503a8865 JW |
1515 | /* JMP */ |
1516 | #define COND_JMP(SIGN, OPCODE, CMP_OP) \ | |
1517 | JMP_##OPCODE##_X: \ | |
1518 | if ((SIGN##64) DST CMP_OP (SIGN##64) SRC) { \ | |
1519 | insn += insn->off; \ | |
1520 | CONT_JMP; \ | |
1521 | } \ | |
1522 | CONT; \ | |
1523 | JMP32_##OPCODE##_X: \ | |
1524 | if ((SIGN##32) DST CMP_OP (SIGN##32) SRC) { \ | |
1525 | insn += insn->off; \ | |
1526 | CONT_JMP; \ | |
1527 | } \ | |
1528 | CONT; \ | |
1529 | JMP_##OPCODE##_K: \ | |
1530 | if ((SIGN##64) DST CMP_OP (SIGN##64) IMM) { \ | |
1531 | insn += insn->off; \ | |
1532 | CONT_JMP; \ | |
1533 | } \ | |
1534 | CONT; \ | |
1535 | JMP32_##OPCODE##_K: \ | |
1536 | if ((SIGN##32) DST CMP_OP (SIGN##32) IMM) { \ | |
1537 | insn += insn->off; \ | |
1538 | CONT_JMP; \ | |
1539 | } \ | |
1540 | CONT; | |
1541 | COND_JMP(u, JEQ, ==) | |
1542 | COND_JMP(u, JNE, !=) | |
1543 | COND_JMP(u, JGT, >) | |
1544 | COND_JMP(u, JLT, <) | |
1545 | COND_JMP(u, JGE, >=) | |
1546 | COND_JMP(u, JLE, <=) | |
1547 | COND_JMP(u, JSET, &) | |
1548 | COND_JMP(s, JSGT, >) | |
1549 | COND_JMP(s, JSLT, <) | |
1550 | COND_JMP(s, JSGE, >=) | |
1551 | COND_JMP(s, JSLE, <=) | |
1552 | #undef COND_JMP | |
f5bffecd AS |
1553 | /* STX and ST and LDX*/ |
1554 | #define LDST(SIZEOP, SIZE) \ | |
1555 | STX_MEM_##SIZEOP: \ | |
1556 | *(SIZE *)(unsigned long) (DST + insn->off) = SRC; \ | |
1557 | CONT; \ | |
1558 | ST_MEM_##SIZEOP: \ | |
1559 | *(SIZE *)(unsigned long) (DST + insn->off) = IMM; \ | |
1560 | CONT; \ | |
1561 | LDX_MEM_##SIZEOP: \ | |
1562 | DST = *(SIZE *)(unsigned long) (SRC + insn->off); \ | |
1563 | CONT; | |
1564 | ||
1565 | LDST(B, u8) | |
1566 | LDST(H, u16) | |
1567 | LDST(W, u32) | |
1568 | LDST(DW, u64) | |
1569 | #undef LDST | |
6e07a634 DB |
1570 | #define LDX_PROBE(SIZEOP, SIZE) \ |
1571 | LDX_PROBE_MEM_##SIZEOP: \ | |
1572 | bpf_probe_read_kernel(&DST, SIZE, (const void *)(long) SRC); \ | |
2a02759e AS |
1573 | CONT; |
1574 | LDX_PROBE(B, 1) | |
1575 | LDX_PROBE(H, 2) | |
1576 | LDX_PROBE(W, 4) | |
1577 | LDX_PROBE(DW, 8) | |
1578 | #undef LDX_PROBE | |
1579 | ||
f5bffecd AS |
1580 | STX_XADD_W: /* lock xadd *(u32 *)(dst_reg + off16) += src_reg */ |
1581 | atomic_add((u32) SRC, (atomic_t *)(unsigned long) | |
1582 | (DST + insn->off)); | |
1583 | CONT; | |
1584 | STX_XADD_DW: /* lock xadd *(u64 *)(dst_reg + off16) += src_reg */ | |
1585 | atomic64_add((u64) SRC, (atomic64_t *)(unsigned long) | |
1586 | (DST + insn->off)); | |
1587 | CONT; | |
f5bffecd AS |
1588 | |
1589 | default_label: | |
5e581dad DB |
1590 | /* If we ever reach this, we have a bug somewhere. Die hard here |
1591 | * instead of just returning 0; we could be somewhere in a subprog, | |
1592 | * so execution could continue otherwise which we do /not/ want. | |
1593 | * | |
1594 | * Note, verifier whitelists all opcodes in bpf_opcode_in_insntable(). | |
1595 | */ | |
1596 | pr_warn("BPF interpreter: unknown opcode %02x\n", insn->code); | |
1597 | BUG_ON(1); | |
f5bffecd AS |
1598 | return 0; |
1599 | } | |
f696b8f4 | 1600 | |
b870aa90 AS |
1601 | #define PROG_NAME(stack_size) __bpf_prog_run##stack_size |
1602 | #define DEFINE_BPF_PROG_RUN(stack_size) \ | |
1603 | static unsigned int PROG_NAME(stack_size)(const void *ctx, const struct bpf_insn *insn) \ | |
1604 | { \ | |
1605 | u64 stack[stack_size / sizeof(u64)]; \ | |
144cd91c | 1606 | u64 regs[MAX_BPF_EXT_REG]; \ |
b870aa90 AS |
1607 | \ |
1608 | FP = (u64) (unsigned long) &stack[ARRAY_SIZE(stack)]; \ | |
1609 | ARG1 = (u64) (unsigned long) ctx; \ | |
1610 | return ___bpf_prog_run(regs, insn, stack); \ | |
f696b8f4 | 1611 | } |
f5bffecd | 1612 | |
1ea47e01 AS |
1613 | #define PROG_NAME_ARGS(stack_size) __bpf_prog_run_args##stack_size |
1614 | #define DEFINE_BPF_PROG_RUN_ARGS(stack_size) \ | |
1615 | static u64 PROG_NAME_ARGS(stack_size)(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5, \ | |
1616 | const struct bpf_insn *insn) \ | |
1617 | { \ | |
1618 | u64 stack[stack_size / sizeof(u64)]; \ | |
144cd91c | 1619 | u64 regs[MAX_BPF_EXT_REG]; \ |
1ea47e01 AS |
1620 | \ |
1621 | FP = (u64) (unsigned long) &stack[ARRAY_SIZE(stack)]; \ | |
1622 | BPF_R1 = r1; \ | |
1623 | BPF_R2 = r2; \ | |
1624 | BPF_R3 = r3; \ | |
1625 | BPF_R4 = r4; \ | |
1626 | BPF_R5 = r5; \ | |
1627 | return ___bpf_prog_run(regs, insn, stack); \ | |
1628 | } | |
1629 | ||
b870aa90 AS |
1630 | #define EVAL1(FN, X) FN(X) |
1631 | #define EVAL2(FN, X, Y...) FN(X) EVAL1(FN, Y) | |
1632 | #define EVAL3(FN, X, Y...) FN(X) EVAL2(FN, Y) | |
1633 | #define EVAL4(FN, X, Y...) FN(X) EVAL3(FN, Y) | |
1634 | #define EVAL5(FN, X, Y...) FN(X) EVAL4(FN, Y) | |
1635 | #define EVAL6(FN, X, Y...) FN(X) EVAL5(FN, Y) | |
1636 | ||
1637 | EVAL6(DEFINE_BPF_PROG_RUN, 32, 64, 96, 128, 160, 192); | |
1638 | EVAL6(DEFINE_BPF_PROG_RUN, 224, 256, 288, 320, 352, 384); | |
1639 | EVAL4(DEFINE_BPF_PROG_RUN, 416, 448, 480, 512); | |
1640 | ||
1ea47e01 AS |
1641 | EVAL6(DEFINE_BPF_PROG_RUN_ARGS, 32, 64, 96, 128, 160, 192); |
1642 | EVAL6(DEFINE_BPF_PROG_RUN_ARGS, 224, 256, 288, 320, 352, 384); | |
1643 | EVAL4(DEFINE_BPF_PROG_RUN_ARGS, 416, 448, 480, 512); | |
1644 | ||
b870aa90 AS |
1645 | #define PROG_NAME_LIST(stack_size) PROG_NAME(stack_size), |
1646 | ||
1647 | static unsigned int (*interpreters[])(const void *ctx, | |
1648 | const struct bpf_insn *insn) = { | |
1649 | EVAL6(PROG_NAME_LIST, 32, 64, 96, 128, 160, 192) | |
1650 | EVAL6(PROG_NAME_LIST, 224, 256, 288, 320, 352, 384) | |
1651 | EVAL4(PROG_NAME_LIST, 416, 448, 480, 512) | |
1652 | }; | |
1ea47e01 AS |
1653 | #undef PROG_NAME_LIST |
1654 | #define PROG_NAME_LIST(stack_size) PROG_NAME_ARGS(stack_size), | |
1655 | static u64 (*interpreters_args[])(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5, | |
1656 | const struct bpf_insn *insn) = { | |
1657 | EVAL6(PROG_NAME_LIST, 32, 64, 96, 128, 160, 192) | |
1658 | EVAL6(PROG_NAME_LIST, 224, 256, 288, 320, 352, 384) | |
1659 | EVAL4(PROG_NAME_LIST, 416, 448, 480, 512) | |
1660 | }; | |
1661 | #undef PROG_NAME_LIST | |
1662 | ||
1663 | void bpf_patch_call_args(struct bpf_insn *insn, u32 stack_depth) | |
1664 | { | |
1665 | stack_depth = max_t(u32, stack_depth, 1); | |
1666 | insn->off = (s16) insn->imm; | |
1667 | insn->imm = interpreters_args[(round_up(stack_depth, 32) / 32) - 1] - | |
1668 | __bpf_call_base_args; | |
1669 | insn->code = BPF_JMP | BPF_CALL_ARGS; | |
1670 | } | |
b870aa90 | 1671 | |
290af866 | 1672 | #else |
fa9dd599 DB |
1673 | static unsigned int __bpf_prog_ret0_warn(const void *ctx, |
1674 | const struct bpf_insn *insn) | |
290af866 | 1675 | { |
fa9dd599 DB |
1676 | /* If this handler ever gets executed, then BPF_JIT_ALWAYS_ON |
1677 | * is not working properly, so warn about it! | |
1678 | */ | |
1679 | WARN_ON_ONCE(1); | |
290af866 AS |
1680 | return 0; |
1681 | } | |
1682 | #endif | |
1683 | ||
3324b584 DB |
1684 | bool bpf_prog_array_compatible(struct bpf_array *array, |
1685 | const struct bpf_prog *fp) | |
04fd61ab | 1686 | { |
9802d865 JB |
1687 | if (fp->kprobe_override) |
1688 | return false; | |
1689 | ||
3324b584 DB |
1690 | if (!array->owner_prog_type) { |
1691 | /* There's no owner yet where we could check for | |
1692 | * compatibility. | |
1693 | */ | |
04fd61ab AS |
1694 | array->owner_prog_type = fp->type; |
1695 | array->owner_jited = fp->jited; | |
3324b584 DB |
1696 | |
1697 | return true; | |
04fd61ab | 1698 | } |
3324b584 DB |
1699 | |
1700 | return array->owner_prog_type == fp->type && | |
1701 | array->owner_jited == fp->jited; | |
04fd61ab AS |
1702 | } |
1703 | ||
3324b584 | 1704 | static int bpf_check_tail_call(const struct bpf_prog *fp) |
04fd61ab AS |
1705 | { |
1706 | struct bpf_prog_aux *aux = fp->aux; | |
1707 | int i; | |
1708 | ||
1709 | for (i = 0; i < aux->used_map_cnt; i++) { | |
3324b584 | 1710 | struct bpf_map *map = aux->used_maps[i]; |
04fd61ab | 1711 | struct bpf_array *array; |
04fd61ab | 1712 | |
04fd61ab AS |
1713 | if (map->map_type != BPF_MAP_TYPE_PROG_ARRAY) |
1714 | continue; | |
3324b584 | 1715 | |
04fd61ab AS |
1716 | array = container_of(map, struct bpf_array, map); |
1717 | if (!bpf_prog_array_compatible(array, fp)) | |
1718 | return -EINVAL; | |
1719 | } | |
1720 | ||
1721 | return 0; | |
1722 | } | |
1723 | ||
9facc336 DB |
1724 | static void bpf_prog_select_func(struct bpf_prog *fp) |
1725 | { | |
1726 | #ifndef CONFIG_BPF_JIT_ALWAYS_ON | |
1727 | u32 stack_depth = max_t(u32, fp->aux->stack_depth, 1); | |
1728 | ||
1729 | fp->bpf_func = interpreters[(round_up(stack_depth, 32) / 32) - 1]; | |
1730 | #else | |
1731 | fp->bpf_func = __bpf_prog_ret0_warn; | |
1732 | #endif | |
1733 | } | |
1734 | ||
f5bffecd | 1735 | /** |
3324b584 | 1736 | * bpf_prog_select_runtime - select exec runtime for BPF program |
7ae457c1 | 1737 | * @fp: bpf_prog populated with internal BPF program |
d1c55ab5 | 1738 | * @err: pointer to error variable |
f5bffecd | 1739 | * |
3324b584 DB |
1740 | * Try to JIT eBPF program, if JIT is not available, use interpreter. |
1741 | * The BPF program will be executed via BPF_PROG_RUN() macro. | |
f5bffecd | 1742 | */ |
d1c55ab5 | 1743 | struct bpf_prog *bpf_prog_select_runtime(struct bpf_prog *fp, int *err) |
f5bffecd | 1744 | { |
9facc336 DB |
1745 | /* In case of BPF to BPF calls, verifier did all the prep |
1746 | * work with regards to JITing, etc. | |
1747 | */ | |
1748 | if (fp->bpf_func) | |
1749 | goto finalize; | |
8007e40a | 1750 | |
9facc336 | 1751 | bpf_prog_select_func(fp); |
f5bffecd | 1752 | |
d1c55ab5 DB |
1753 | /* eBPF JITs can rewrite the program in case constant |
1754 | * blinding is active. However, in case of error during | |
1755 | * blinding, bpf_int_jit_compile() must always return a | |
1756 | * valid program, which in this case would simply not | |
1757 | * be JITed, but falls back to the interpreter. | |
1758 | */ | |
ab3f0063 | 1759 | if (!bpf_prog_is_dev_bound(fp->aux)) { |
c454a46b MKL |
1760 | *err = bpf_prog_alloc_jited_linfo(fp); |
1761 | if (*err) | |
1762 | return fp; | |
1763 | ||
ab3f0063 | 1764 | fp = bpf_int_jit_compile(fp); |
290af866 | 1765 | if (!fp->jited) { |
c454a46b MKL |
1766 | bpf_prog_free_jited_linfo(fp); |
1767 | #ifdef CONFIG_BPF_JIT_ALWAYS_ON | |
290af866 AS |
1768 | *err = -ENOTSUPP; |
1769 | return fp; | |
290af866 | 1770 | #endif |
c454a46b MKL |
1771 | } else { |
1772 | bpf_prog_free_unused_jited_linfo(fp); | |
1773 | } | |
ab3f0063 JK |
1774 | } else { |
1775 | *err = bpf_prog_offload_compile(fp); | |
1776 | if (*err) | |
1777 | return fp; | |
1778 | } | |
9facc336 DB |
1779 | |
1780 | finalize: | |
60a3b225 | 1781 | bpf_prog_lock_ro(fp); |
04fd61ab | 1782 | |
3324b584 DB |
1783 | /* The tail call compatibility check can only be done at |
1784 | * this late stage as we need to determine, if we deal | |
1785 | * with JITed or non JITed program concatenations and not | |
1786 | * all eBPF JITs might immediately support all features. | |
1787 | */ | |
d1c55ab5 | 1788 | *err = bpf_check_tail_call(fp); |
85782e03 | 1789 | |
d1c55ab5 | 1790 | return fp; |
f5bffecd | 1791 | } |
7ae457c1 | 1792 | EXPORT_SYMBOL_GPL(bpf_prog_select_runtime); |
f5bffecd | 1793 | |
e87c6bc3 YS |
1794 | static unsigned int __bpf_prog_ret1(const void *ctx, |
1795 | const struct bpf_insn *insn) | |
1796 | { | |
1797 | return 1; | |
1798 | } | |
1799 | ||
1800 | static struct bpf_prog_dummy { | |
1801 | struct bpf_prog prog; | |
1802 | } dummy_bpf_prog = { | |
1803 | .prog = { | |
1804 | .bpf_func = __bpf_prog_ret1, | |
1805 | }, | |
1806 | }; | |
1807 | ||
324bda9e AS |
1808 | /* to avoid allocating empty bpf_prog_array for cgroups that |
1809 | * don't have bpf program attached use one global 'empty_prog_array' | |
1810 | * It will not be modified the caller of bpf_prog_array_alloc() | |
1811 | * (since caller requested prog_cnt == 0) | |
1812 | * that pointer should be 'freed' by bpf_prog_array_free() | |
1813 | */ | |
1814 | static struct { | |
1815 | struct bpf_prog_array hdr; | |
1816 | struct bpf_prog *null_prog; | |
1817 | } empty_prog_array = { | |
1818 | .null_prog = NULL, | |
1819 | }; | |
1820 | ||
d29ab6e1 | 1821 | struct bpf_prog_array *bpf_prog_array_alloc(u32 prog_cnt, gfp_t flags) |
324bda9e AS |
1822 | { |
1823 | if (prog_cnt) | |
1824 | return kzalloc(sizeof(struct bpf_prog_array) + | |
394e40a2 RG |
1825 | sizeof(struct bpf_prog_array_item) * |
1826 | (prog_cnt + 1), | |
324bda9e AS |
1827 | flags); |
1828 | ||
1829 | return &empty_prog_array.hdr; | |
1830 | } | |
1831 | ||
54e9c9d4 | 1832 | void bpf_prog_array_free(struct bpf_prog_array *progs) |
324bda9e | 1833 | { |
54e9c9d4 | 1834 | if (!progs || progs == &empty_prog_array.hdr) |
324bda9e AS |
1835 | return; |
1836 | kfree_rcu(progs, rcu); | |
1837 | } | |
1838 | ||
54e9c9d4 | 1839 | int bpf_prog_array_length(struct bpf_prog_array *array) |
468e2f64 | 1840 | { |
394e40a2 | 1841 | struct bpf_prog_array_item *item; |
468e2f64 AS |
1842 | u32 cnt = 0; |
1843 | ||
54e9c9d4 | 1844 | for (item = array->items; item->prog; item++) |
394e40a2 | 1845 | if (item->prog != &dummy_bpf_prog.prog) |
c8c088ba | 1846 | cnt++; |
468e2f64 AS |
1847 | return cnt; |
1848 | } | |
1849 | ||
0d01da6a SF |
1850 | bool bpf_prog_array_is_empty(struct bpf_prog_array *array) |
1851 | { | |
1852 | struct bpf_prog_array_item *item; | |
1853 | ||
1854 | for (item = array->items; item->prog; item++) | |
1855 | if (item->prog != &dummy_bpf_prog.prog) | |
1856 | return false; | |
1857 | return true; | |
1858 | } | |
394e40a2 | 1859 | |
54e9c9d4 | 1860 | static bool bpf_prog_array_copy_core(struct bpf_prog_array *array, |
3a38bb98 YS |
1861 | u32 *prog_ids, |
1862 | u32 request_cnt) | |
1863 | { | |
394e40a2 | 1864 | struct bpf_prog_array_item *item; |
3a38bb98 YS |
1865 | int i = 0; |
1866 | ||
54e9c9d4 | 1867 | for (item = array->items; item->prog; item++) { |
394e40a2 | 1868 | if (item->prog == &dummy_bpf_prog.prog) |
3a38bb98 | 1869 | continue; |
394e40a2 | 1870 | prog_ids[i] = item->prog->aux->id; |
3a38bb98 | 1871 | if (++i == request_cnt) { |
394e40a2 | 1872 | item++; |
3a38bb98 YS |
1873 | break; |
1874 | } | |
1875 | } | |
1876 | ||
394e40a2 | 1877 | return !!(item->prog); |
3a38bb98 YS |
1878 | } |
1879 | ||
54e9c9d4 | 1880 | int bpf_prog_array_copy_to_user(struct bpf_prog_array *array, |
468e2f64 AS |
1881 | __u32 __user *prog_ids, u32 cnt) |
1882 | { | |
0911287c | 1883 | unsigned long err = 0; |
0911287c | 1884 | bool nospc; |
3a38bb98 | 1885 | u32 *ids; |
0911287c AS |
1886 | |
1887 | /* users of this function are doing: | |
1888 | * cnt = bpf_prog_array_length(); | |
1889 | * if (cnt > 0) | |
1890 | * bpf_prog_array_copy_to_user(..., cnt); | |
54e9c9d4 | 1891 | * so below kcalloc doesn't need extra cnt > 0 check. |
0911287c | 1892 | */ |
9c481b90 | 1893 | ids = kcalloc(cnt, sizeof(u32), GFP_USER | __GFP_NOWARN); |
0911287c AS |
1894 | if (!ids) |
1895 | return -ENOMEM; | |
394e40a2 | 1896 | nospc = bpf_prog_array_copy_core(array, ids, cnt); |
0911287c AS |
1897 | err = copy_to_user(prog_ids, ids, cnt * sizeof(u32)); |
1898 | kfree(ids); | |
1899 | if (err) | |
1900 | return -EFAULT; | |
1901 | if (nospc) | |
468e2f64 AS |
1902 | return -ENOSPC; |
1903 | return 0; | |
1904 | } | |
1905 | ||
54e9c9d4 | 1906 | void bpf_prog_array_delete_safe(struct bpf_prog_array *array, |
e87c6bc3 YS |
1907 | struct bpf_prog *old_prog) |
1908 | { | |
54e9c9d4 | 1909 | struct bpf_prog_array_item *item; |
e87c6bc3 | 1910 | |
54e9c9d4 | 1911 | for (item = array->items; item->prog; item++) |
394e40a2 RG |
1912 | if (item->prog == old_prog) { |
1913 | WRITE_ONCE(item->prog, &dummy_bpf_prog.prog); | |
e87c6bc3 YS |
1914 | break; |
1915 | } | |
1916 | } | |
1917 | ||
54e9c9d4 | 1918 | int bpf_prog_array_copy(struct bpf_prog_array *old_array, |
e87c6bc3 YS |
1919 | struct bpf_prog *exclude_prog, |
1920 | struct bpf_prog *include_prog, | |
1921 | struct bpf_prog_array **new_array) | |
1922 | { | |
1923 | int new_prog_cnt, carry_prog_cnt = 0; | |
394e40a2 | 1924 | struct bpf_prog_array_item *existing; |
e87c6bc3 | 1925 | struct bpf_prog_array *array; |
170a7e3e | 1926 | bool found_exclude = false; |
e87c6bc3 YS |
1927 | int new_prog_idx = 0; |
1928 | ||
1929 | /* Figure out how many existing progs we need to carry over to | |
1930 | * the new array. | |
1931 | */ | |
1932 | if (old_array) { | |
394e40a2 RG |
1933 | existing = old_array->items; |
1934 | for (; existing->prog; existing++) { | |
1935 | if (existing->prog == exclude_prog) { | |
170a7e3e SY |
1936 | found_exclude = true; |
1937 | continue; | |
1938 | } | |
394e40a2 | 1939 | if (existing->prog != &dummy_bpf_prog.prog) |
e87c6bc3 | 1940 | carry_prog_cnt++; |
394e40a2 | 1941 | if (existing->prog == include_prog) |
e87c6bc3 YS |
1942 | return -EEXIST; |
1943 | } | |
1944 | } | |
1945 | ||
170a7e3e SY |
1946 | if (exclude_prog && !found_exclude) |
1947 | return -ENOENT; | |
1948 | ||
e87c6bc3 YS |
1949 | /* How many progs (not NULL) will be in the new array? */ |
1950 | new_prog_cnt = carry_prog_cnt; | |
1951 | if (include_prog) | |
1952 | new_prog_cnt += 1; | |
1953 | ||
1954 | /* Do we have any prog (not NULL) in the new array? */ | |
1955 | if (!new_prog_cnt) { | |
1956 | *new_array = NULL; | |
1957 | return 0; | |
1958 | } | |
1959 | ||
1960 | /* +1 as the end of prog_array is marked with NULL */ | |
1961 | array = bpf_prog_array_alloc(new_prog_cnt + 1, GFP_KERNEL); | |
1962 | if (!array) | |
1963 | return -ENOMEM; | |
1964 | ||
1965 | /* Fill in the new prog array */ | |
1966 | if (carry_prog_cnt) { | |
394e40a2 RG |
1967 | existing = old_array->items; |
1968 | for (; existing->prog; existing++) | |
1969 | if (existing->prog != exclude_prog && | |
1970 | existing->prog != &dummy_bpf_prog.prog) { | |
1971 | array->items[new_prog_idx++].prog = | |
1972 | existing->prog; | |
1973 | } | |
e87c6bc3 YS |
1974 | } |
1975 | if (include_prog) | |
394e40a2 RG |
1976 | array->items[new_prog_idx++].prog = include_prog; |
1977 | array->items[new_prog_idx].prog = NULL; | |
e87c6bc3 YS |
1978 | *new_array = array; |
1979 | return 0; | |
1980 | } | |
1981 | ||
54e9c9d4 | 1982 | int bpf_prog_array_copy_info(struct bpf_prog_array *array, |
3a38bb98 YS |
1983 | u32 *prog_ids, u32 request_cnt, |
1984 | u32 *prog_cnt) | |
f371b304 YS |
1985 | { |
1986 | u32 cnt = 0; | |
1987 | ||
1988 | if (array) | |
1989 | cnt = bpf_prog_array_length(array); | |
1990 | ||
3a38bb98 | 1991 | *prog_cnt = cnt; |
f371b304 YS |
1992 | |
1993 | /* return early if user requested only program count or nothing to copy */ | |
1994 | if (!request_cnt || !cnt) | |
1995 | return 0; | |
1996 | ||
3a38bb98 | 1997 | /* this function is called under trace/bpf_trace.c: bpf_event_mutex */ |
394e40a2 | 1998 | return bpf_prog_array_copy_core(array, prog_ids, request_cnt) ? -ENOSPC |
3a38bb98 | 1999 | : 0; |
f371b304 YS |
2000 | } |
2001 | ||
60a3b225 DB |
2002 | static void bpf_prog_free_deferred(struct work_struct *work) |
2003 | { | |
09756af4 | 2004 | struct bpf_prog_aux *aux; |
1c2a088a | 2005 | int i; |
60a3b225 | 2006 | |
09756af4 | 2007 | aux = container_of(work, struct bpf_prog_aux, work); |
ab3f0063 JK |
2008 | if (bpf_prog_is_dev_bound(aux)) |
2009 | bpf_prog_offload_destroy(aux->prog); | |
c195651e YS |
2010 | #ifdef CONFIG_PERF_EVENTS |
2011 | if (aux->prog->has_callchain_buf) | |
2012 | put_callchain_buffers(); | |
2013 | #endif | |
1c2a088a AS |
2014 | for (i = 0; i < aux->func_cnt; i++) |
2015 | bpf_jit_free(aux->func[i]); | |
2016 | if (aux->func_cnt) { | |
2017 | kfree(aux->func); | |
2018 | bpf_prog_unlock_free(aux->prog); | |
2019 | } else { | |
2020 | bpf_jit_free(aux->prog); | |
2021 | } | |
60a3b225 DB |
2022 | } |
2023 | ||
2024 | /* Free internal BPF program */ | |
7ae457c1 | 2025 | void bpf_prog_free(struct bpf_prog *fp) |
f5bffecd | 2026 | { |
09756af4 | 2027 | struct bpf_prog_aux *aux = fp->aux; |
60a3b225 | 2028 | |
09756af4 | 2029 | INIT_WORK(&aux->work, bpf_prog_free_deferred); |
09756af4 | 2030 | schedule_work(&aux->work); |
f5bffecd | 2031 | } |
7ae457c1 | 2032 | EXPORT_SYMBOL_GPL(bpf_prog_free); |
f89b7755 | 2033 | |
3ad00405 DB |
2034 | /* RNG for unpriviledged user space with separated state from prandom_u32(). */ |
2035 | static DEFINE_PER_CPU(struct rnd_state, bpf_user_rnd_state); | |
2036 | ||
2037 | void bpf_user_rnd_init_once(void) | |
2038 | { | |
2039 | prandom_init_once(&bpf_user_rnd_state); | |
2040 | } | |
2041 | ||
f3694e00 | 2042 | BPF_CALL_0(bpf_user_rnd_u32) |
3ad00405 DB |
2043 | { |
2044 | /* Should someone ever have the rather unwise idea to use some | |
2045 | * of the registers passed into this function, then note that | |
2046 | * this function is called from native eBPF and classic-to-eBPF | |
2047 | * transformations. Register assignments from both sides are | |
2048 | * different, f.e. classic always sets fn(ctx, A, X) here. | |
2049 | */ | |
2050 | struct rnd_state *state; | |
2051 | u32 res; | |
2052 | ||
2053 | state = &get_cpu_var(bpf_user_rnd_state); | |
2054 | res = prandom_u32_state(state); | |
b761fe22 | 2055 | put_cpu_var(bpf_user_rnd_state); |
3ad00405 DB |
2056 | |
2057 | return res; | |
2058 | } | |
2059 | ||
3ba67dab DB |
2060 | /* Weak definitions of helper functions in case we don't have bpf syscall. */ |
2061 | const struct bpf_func_proto bpf_map_lookup_elem_proto __weak; | |
2062 | const struct bpf_func_proto bpf_map_update_elem_proto __weak; | |
2063 | const struct bpf_func_proto bpf_map_delete_elem_proto __weak; | |
f1a2e44a MV |
2064 | const struct bpf_func_proto bpf_map_push_elem_proto __weak; |
2065 | const struct bpf_func_proto bpf_map_pop_elem_proto __weak; | |
2066 | const struct bpf_func_proto bpf_map_peek_elem_proto __weak; | |
d83525ca AS |
2067 | const struct bpf_func_proto bpf_spin_lock_proto __weak; |
2068 | const struct bpf_func_proto bpf_spin_unlock_proto __weak; | |
3ba67dab | 2069 | |
03e69b50 | 2070 | const struct bpf_func_proto bpf_get_prandom_u32_proto __weak; |
c04167ce | 2071 | const struct bpf_func_proto bpf_get_smp_processor_id_proto __weak; |
2d0e30c3 | 2072 | const struct bpf_func_proto bpf_get_numa_node_id_proto __weak; |
17ca8cbf | 2073 | const struct bpf_func_proto bpf_ktime_get_ns_proto __weak; |
bd570ff9 | 2074 | |
ffeedafb AS |
2075 | const struct bpf_func_proto bpf_get_current_pid_tgid_proto __weak; |
2076 | const struct bpf_func_proto bpf_get_current_uid_gid_proto __weak; | |
2077 | const struct bpf_func_proto bpf_get_current_comm_proto __weak; | |
bf6fa2c8 | 2078 | const struct bpf_func_proto bpf_get_current_cgroup_id_proto __weak; |
cd339431 | 2079 | const struct bpf_func_proto bpf_get_local_storage_proto __weak; |
bd570ff9 | 2080 | |
0756ea3e AS |
2081 | const struct bpf_func_proto * __weak bpf_get_trace_printk_proto(void) |
2082 | { | |
2083 | return NULL; | |
2084 | } | |
03e69b50 | 2085 | |
555c8a86 DB |
2086 | u64 __weak |
2087 | bpf_event_output(struct bpf_map *map, u64 flags, void *meta, u64 meta_size, | |
2088 | void *ctx, u64 ctx_size, bpf_ctx_copy_t ctx_copy) | |
bd570ff9 | 2089 | { |
555c8a86 | 2090 | return -ENOTSUPP; |
bd570ff9 | 2091 | } |
6cb5fb38 | 2092 | EXPORT_SYMBOL_GPL(bpf_event_output); |
bd570ff9 | 2093 | |
3324b584 DB |
2094 | /* Always built-in helper functions. */ |
2095 | const struct bpf_func_proto bpf_tail_call_proto = { | |
2096 | .func = NULL, | |
2097 | .gpl_only = false, | |
2098 | .ret_type = RET_VOID, | |
2099 | .arg1_type = ARG_PTR_TO_CTX, | |
2100 | .arg2_type = ARG_CONST_MAP_PTR, | |
2101 | .arg3_type = ARG_ANYTHING, | |
2102 | }; | |
2103 | ||
9383191d DB |
2104 | /* Stub for JITs that only support cBPF. eBPF programs are interpreted. |
2105 | * It is encouraged to implement bpf_int_jit_compile() instead, so that | |
2106 | * eBPF and implicitly also cBPF can get JITed! | |
2107 | */ | |
d1c55ab5 | 2108 | struct bpf_prog * __weak bpf_int_jit_compile(struct bpf_prog *prog) |
3324b584 | 2109 | { |
d1c55ab5 | 2110 | return prog; |
3324b584 DB |
2111 | } |
2112 | ||
9383191d DB |
2113 | /* Stub for JITs that support eBPF. All cBPF code gets transformed into |
2114 | * eBPF by the kernel and is later compiled by bpf_int_jit_compile(). | |
2115 | */ | |
2116 | void __weak bpf_jit_compile(struct bpf_prog *prog) | |
2117 | { | |
2118 | } | |
2119 | ||
17bedab2 | 2120 | bool __weak bpf_helper_changes_pkt_data(void *func) |
969bf05e AS |
2121 | { |
2122 | return false; | |
2123 | } | |
2124 | ||
a4b1d3c1 JW |
2125 | /* Return TRUE if the JIT backend wants verifier to enable sub-register usage |
2126 | * analysis code and wants explicit zero extension inserted by verifier. | |
2127 | * Otherwise, return FALSE. | |
2128 | */ | |
2129 | bool __weak bpf_jit_needs_zext(void) | |
2130 | { | |
2131 | return false; | |
2132 | } | |
2133 | ||
f89b7755 AS |
2134 | /* To execute LD_ABS/LD_IND instructions __bpf_prog_run() may call |
2135 | * skb_copy_bits(), so provide a weak definition of it for NET-less config. | |
2136 | */ | |
2137 | int __weak skb_copy_bits(const struct sk_buff *skb, int offset, void *to, | |
2138 | int len) | |
2139 | { | |
2140 | return -EFAULT; | |
2141 | } | |
a67edbf4 | 2142 | |
492ecee8 AS |
2143 | DEFINE_STATIC_KEY_FALSE(bpf_stats_enabled_key); |
2144 | EXPORT_SYMBOL(bpf_stats_enabled_key); | |
492ecee8 | 2145 | |
a67edbf4 DB |
2146 | /* All definitions of tracepoints related to BPF. */ |
2147 | #define CREATE_TRACE_POINTS | |
2148 | #include <linux/bpf_trace.h> | |
2149 | ||
2150 | EXPORT_TRACEPOINT_SYMBOL_GPL(xdp_exception); | |
e7d47989 | 2151 | EXPORT_TRACEPOINT_SYMBOL_GPL(xdp_bulk_tx); |