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> |
b7b3fc8d | 34 | #include <linux/log2.h> |
3324b584 DB |
35 | #include <asm/unaligned.h> |
36 | ||
f5bffecd AS |
37 | /* Registers */ |
38 | #define BPF_R0 regs[BPF_REG_0] | |
39 | #define BPF_R1 regs[BPF_REG_1] | |
40 | #define BPF_R2 regs[BPF_REG_2] | |
41 | #define BPF_R3 regs[BPF_REG_3] | |
42 | #define BPF_R4 regs[BPF_REG_4] | |
43 | #define BPF_R5 regs[BPF_REG_5] | |
44 | #define BPF_R6 regs[BPF_REG_6] | |
45 | #define BPF_R7 regs[BPF_REG_7] | |
46 | #define BPF_R8 regs[BPF_REG_8] | |
47 | #define BPF_R9 regs[BPF_REG_9] | |
48 | #define BPF_R10 regs[BPF_REG_10] | |
49 | ||
50 | /* Named registers */ | |
51 | #define DST regs[insn->dst_reg] | |
52 | #define SRC regs[insn->src_reg] | |
53 | #define FP regs[BPF_REG_FP] | |
144cd91c | 54 | #define AX regs[BPF_REG_AX] |
f5bffecd AS |
55 | #define ARG1 regs[BPF_REG_ARG1] |
56 | #define CTX regs[BPF_REG_CTX] | |
57 | #define IMM insn->imm | |
58 | ||
59 | /* No hurry in this branch | |
60 | * | |
61 | * Exported for the bpf jit load helper. | |
62 | */ | |
63 | void *bpf_internal_load_pointer_neg_helper(const struct sk_buff *skb, int k, unsigned int size) | |
64 | { | |
65 | u8 *ptr = NULL; | |
66 | ||
67 | if (k >= SKF_NET_OFF) | |
68 | ptr = skb_network_header(skb) + k - SKF_NET_OFF; | |
69 | else if (k >= SKF_LL_OFF) | |
70 | ptr = skb_mac_header(skb) + k - SKF_LL_OFF; | |
3324b584 | 71 | |
f5bffecd AS |
72 | if (ptr >= skb->head && ptr + size <= skb_tail_pointer(skb)) |
73 | return ptr; | |
74 | ||
75 | return NULL; | |
76 | } | |
77 | ||
492ecee8 | 78 | struct bpf_prog *bpf_prog_alloc_no_stats(unsigned int size, gfp_t gfp_extra_flags) |
60a3b225 | 79 | { |
19809c2d | 80 | gfp_t gfp_flags = GFP_KERNEL | __GFP_ZERO | gfp_extra_flags; |
09756af4 | 81 | struct bpf_prog_aux *aux; |
60a3b225 DB |
82 | struct bpf_prog *fp; |
83 | ||
84 | size = round_up(size, PAGE_SIZE); | |
85 | fp = __vmalloc(size, gfp_flags, PAGE_KERNEL); | |
86 | if (fp == NULL) | |
87 | return NULL; | |
88 | ||
09756af4 AS |
89 | aux = kzalloc(sizeof(*aux), GFP_KERNEL | gfp_extra_flags); |
90 | if (aux == NULL) { | |
60a3b225 DB |
91 | vfree(fp); |
92 | return NULL; | |
93 | } | |
94 | ||
95 | fp->pages = size / PAGE_SIZE; | |
09756af4 | 96 | fp->aux = aux; |
e9d8afa9 | 97 | fp->aux->prog = fp; |
60b58afc | 98 | fp->jit_requested = ebpf_jit_enabled(); |
60a3b225 | 99 | |
74451e66 DB |
100 | INIT_LIST_HEAD_RCU(&fp->aux->ksym_lnode); |
101 | ||
60a3b225 DB |
102 | return fp; |
103 | } | |
492ecee8 AS |
104 | |
105 | struct bpf_prog *bpf_prog_alloc(unsigned int size, gfp_t gfp_extra_flags) | |
106 | { | |
107 | gfp_t gfp_flags = GFP_KERNEL | __GFP_ZERO | gfp_extra_flags; | |
108 | struct bpf_prog *prog; | |
4b911304 | 109 | int cpu; |
492ecee8 AS |
110 | |
111 | prog = bpf_prog_alloc_no_stats(size, gfp_extra_flags); | |
112 | if (!prog) | |
113 | return NULL; | |
114 | ||
115 | prog->aux->stats = alloc_percpu_gfp(struct bpf_prog_stats, gfp_flags); | |
116 | if (!prog->aux->stats) { | |
117 | kfree(prog->aux); | |
118 | vfree(prog); | |
119 | return NULL; | |
120 | } | |
121 | ||
4b911304 ED |
122 | for_each_possible_cpu(cpu) { |
123 | struct bpf_prog_stats *pstats; | |
124 | ||
125 | pstats = per_cpu_ptr(prog->aux->stats, cpu); | |
126 | u64_stats_init(&pstats->syncp); | |
127 | } | |
492ecee8 AS |
128 | return prog; |
129 | } | |
60a3b225 DB |
130 | EXPORT_SYMBOL_GPL(bpf_prog_alloc); |
131 | ||
c454a46b MKL |
132 | int bpf_prog_alloc_jited_linfo(struct bpf_prog *prog) |
133 | { | |
134 | if (!prog->aux->nr_linfo || !prog->jit_requested) | |
135 | return 0; | |
136 | ||
137 | prog->aux->jited_linfo = kcalloc(prog->aux->nr_linfo, | |
138 | sizeof(*prog->aux->jited_linfo), | |
139 | GFP_KERNEL | __GFP_NOWARN); | |
140 | if (!prog->aux->jited_linfo) | |
141 | return -ENOMEM; | |
142 | ||
143 | return 0; | |
144 | } | |
145 | ||
146 | void bpf_prog_free_jited_linfo(struct bpf_prog *prog) | |
147 | { | |
148 | kfree(prog->aux->jited_linfo); | |
149 | prog->aux->jited_linfo = NULL; | |
150 | } | |
151 | ||
152 | void bpf_prog_free_unused_jited_linfo(struct bpf_prog *prog) | |
153 | { | |
154 | if (prog->aux->jited_linfo && !prog->aux->jited_linfo[0]) | |
155 | bpf_prog_free_jited_linfo(prog); | |
156 | } | |
157 | ||
158 | /* The jit engine is responsible to provide an array | |
159 | * for insn_off to the jited_off mapping (insn_to_jit_off). | |
160 | * | |
161 | * The idx to this array is the insn_off. Hence, the insn_off | |
162 | * here is relative to the prog itself instead of the main prog. | |
163 | * This array has one entry for each xlated bpf insn. | |
164 | * | |
165 | * jited_off is the byte off to the last byte of the jited insn. | |
166 | * | |
167 | * Hence, with | |
168 | * insn_start: | |
169 | * The first bpf insn off of the prog. The insn off | |
170 | * here is relative to the main prog. | |
171 | * e.g. if prog is a subprog, insn_start > 0 | |
172 | * linfo_idx: | |
173 | * The prog's idx to prog->aux->linfo and jited_linfo | |
174 | * | |
175 | * jited_linfo[linfo_idx] = prog->bpf_func | |
176 | * | |
177 | * For i > linfo_idx, | |
178 | * | |
179 | * jited_linfo[i] = prog->bpf_func + | |
180 | * insn_to_jit_off[linfo[i].insn_off - insn_start - 1] | |
181 | */ | |
182 | void bpf_prog_fill_jited_linfo(struct bpf_prog *prog, | |
183 | const u32 *insn_to_jit_off) | |
184 | { | |
185 | u32 linfo_idx, insn_start, insn_end, nr_linfo, i; | |
186 | const struct bpf_line_info *linfo; | |
187 | void **jited_linfo; | |
188 | ||
189 | if (!prog->aux->jited_linfo) | |
190 | /* Userspace did not provide linfo */ | |
191 | return; | |
192 | ||
193 | linfo_idx = prog->aux->linfo_idx; | |
194 | linfo = &prog->aux->linfo[linfo_idx]; | |
195 | insn_start = linfo[0].insn_off; | |
196 | insn_end = insn_start + prog->len; | |
197 | ||
198 | jited_linfo = &prog->aux->jited_linfo[linfo_idx]; | |
199 | jited_linfo[0] = prog->bpf_func; | |
200 | ||
201 | nr_linfo = prog->aux->nr_linfo - linfo_idx; | |
202 | ||
203 | for (i = 1; i < nr_linfo && linfo[i].insn_off < insn_end; i++) | |
204 | /* The verifier ensures that linfo[i].insn_off is | |
205 | * strictly increasing | |
206 | */ | |
207 | jited_linfo[i] = prog->bpf_func + | |
208 | insn_to_jit_off[linfo[i].insn_off - insn_start - 1]; | |
209 | } | |
210 | ||
211 | void bpf_prog_free_linfo(struct bpf_prog *prog) | |
212 | { | |
213 | bpf_prog_free_jited_linfo(prog); | |
214 | kvfree(prog->aux->linfo); | |
215 | } | |
216 | ||
60a3b225 DB |
217 | struct bpf_prog *bpf_prog_realloc(struct bpf_prog *fp_old, unsigned int size, |
218 | gfp_t gfp_extra_flags) | |
219 | { | |
19809c2d | 220 | gfp_t gfp_flags = GFP_KERNEL | __GFP_ZERO | gfp_extra_flags; |
60a3b225 | 221 | struct bpf_prog *fp; |
5ccb071e DB |
222 | u32 pages, delta; |
223 | int ret; | |
60a3b225 DB |
224 | |
225 | BUG_ON(fp_old == NULL); | |
226 | ||
227 | size = round_up(size, PAGE_SIZE); | |
5ccb071e DB |
228 | pages = size / PAGE_SIZE; |
229 | if (pages <= fp_old->pages) | |
60a3b225 DB |
230 | return fp_old; |
231 | ||
5ccb071e DB |
232 | delta = pages - fp_old->pages; |
233 | ret = __bpf_prog_charge(fp_old->aux->user, delta); | |
234 | if (ret) | |
235 | return NULL; | |
236 | ||
60a3b225 | 237 | fp = __vmalloc(size, gfp_flags, PAGE_KERNEL); |
5ccb071e DB |
238 | if (fp == NULL) { |
239 | __bpf_prog_uncharge(fp_old->aux->user, delta); | |
240 | } else { | |
60a3b225 | 241 | memcpy(fp, fp_old, fp_old->pages * PAGE_SIZE); |
5ccb071e | 242 | fp->pages = pages; |
e9d8afa9 | 243 | fp->aux->prog = fp; |
60a3b225 | 244 | |
09756af4 | 245 | /* We keep fp->aux from fp_old around in the new |
60a3b225 DB |
246 | * reallocated structure. |
247 | */ | |
09756af4 | 248 | fp_old->aux = NULL; |
60a3b225 DB |
249 | __bpf_prog_free(fp_old); |
250 | } | |
251 | ||
252 | return fp; | |
253 | } | |
60a3b225 DB |
254 | |
255 | void __bpf_prog_free(struct bpf_prog *fp) | |
256 | { | |
492ecee8 AS |
257 | if (fp->aux) { |
258 | free_percpu(fp->aux->stats); | |
a66886fe | 259 | kfree(fp->aux->poke_tab); |
492ecee8 AS |
260 | kfree(fp->aux); |
261 | } | |
60a3b225 DB |
262 | vfree(fp); |
263 | } | |
60a3b225 | 264 | |
f1f7714e | 265 | int bpf_prog_calc_tag(struct bpf_prog *fp) |
7bd509e3 DB |
266 | { |
267 | const u32 bits_offset = SHA_MESSAGE_BYTES - sizeof(__be64); | |
f1f7714e DB |
268 | u32 raw_size = bpf_prog_tag_scratch_size(fp); |
269 | u32 digest[SHA_DIGEST_WORDS]; | |
aafe6ae9 | 270 | u32 ws[SHA_WORKSPACE_WORDS]; |
7bd509e3 | 271 | u32 i, bsize, psize, blocks; |
aafe6ae9 | 272 | struct bpf_insn *dst; |
7bd509e3 | 273 | bool was_ld_map; |
aafe6ae9 | 274 | u8 *raw, *todo; |
7bd509e3 DB |
275 | __be32 *result; |
276 | __be64 *bits; | |
277 | ||
aafe6ae9 DB |
278 | raw = vmalloc(raw_size); |
279 | if (!raw) | |
280 | return -ENOMEM; | |
281 | ||
f1f7714e | 282 | sha_init(digest); |
7bd509e3 DB |
283 | memset(ws, 0, sizeof(ws)); |
284 | ||
285 | /* We need to take out the map fd for the digest calculation | |
286 | * since they are unstable from user space side. | |
287 | */ | |
aafe6ae9 | 288 | dst = (void *)raw; |
7bd509e3 DB |
289 | for (i = 0, was_ld_map = false; i < fp->len; i++) { |
290 | dst[i] = fp->insnsi[i]; | |
291 | if (!was_ld_map && | |
292 | dst[i].code == (BPF_LD | BPF_IMM | BPF_DW) && | |
d8eca5bb DB |
293 | (dst[i].src_reg == BPF_PSEUDO_MAP_FD || |
294 | dst[i].src_reg == BPF_PSEUDO_MAP_VALUE)) { | |
7bd509e3 DB |
295 | was_ld_map = true; |
296 | dst[i].imm = 0; | |
297 | } else if (was_ld_map && | |
298 | dst[i].code == 0 && | |
299 | dst[i].dst_reg == 0 && | |
300 | dst[i].src_reg == 0 && | |
301 | dst[i].off == 0) { | |
302 | was_ld_map = false; | |
303 | dst[i].imm = 0; | |
304 | } else { | |
305 | was_ld_map = false; | |
306 | } | |
307 | } | |
308 | ||
aafe6ae9 DB |
309 | psize = bpf_prog_insn_size(fp); |
310 | memset(&raw[psize], 0, raw_size - psize); | |
7bd509e3 DB |
311 | raw[psize++] = 0x80; |
312 | ||
313 | bsize = round_up(psize, SHA_MESSAGE_BYTES); | |
314 | blocks = bsize / SHA_MESSAGE_BYTES; | |
aafe6ae9 | 315 | todo = raw; |
7bd509e3 DB |
316 | if (bsize - psize >= sizeof(__be64)) { |
317 | bits = (__be64 *)(todo + bsize - sizeof(__be64)); | |
318 | } else { | |
319 | bits = (__be64 *)(todo + bsize + bits_offset); | |
320 | blocks++; | |
321 | } | |
322 | *bits = cpu_to_be64((psize - 1) << 3); | |
323 | ||
324 | while (blocks--) { | |
f1f7714e | 325 | sha_transform(digest, todo, ws); |
7bd509e3 DB |
326 | todo += SHA_MESSAGE_BYTES; |
327 | } | |
328 | ||
f1f7714e | 329 | result = (__force __be32 *)digest; |
7bd509e3 | 330 | for (i = 0; i < SHA_DIGEST_WORDS; i++) |
f1f7714e DB |
331 | result[i] = cpu_to_be32(digest[i]); |
332 | memcpy(fp->tag, result, sizeof(fp->tag)); | |
aafe6ae9 DB |
333 | |
334 | vfree(raw); | |
335 | return 0; | |
7bd509e3 DB |
336 | } |
337 | ||
2cbd95a5 | 338 | static int bpf_adj_delta_to_imm(struct bpf_insn *insn, u32 pos, s32 end_old, |
af959b18 | 339 | s32 end_new, s32 curr, const bool probe_pass) |
c237ee5e | 340 | { |
050fad7c | 341 | const s64 imm_min = S32_MIN, imm_max = S32_MAX; |
2cbd95a5 | 342 | s32 delta = end_new - end_old; |
050fad7c DB |
343 | s64 imm = insn->imm; |
344 | ||
2cbd95a5 | 345 | if (curr < pos && curr + imm + 1 >= end_old) |
050fad7c | 346 | imm += delta; |
2cbd95a5 | 347 | else if (curr >= end_new && curr + imm + 1 < end_new) |
050fad7c DB |
348 | imm -= delta; |
349 | if (imm < imm_min || imm > imm_max) | |
350 | return -ERANGE; | |
351 | if (!probe_pass) | |
352 | insn->imm = imm; | |
353 | return 0; | |
354 | } | |
355 | ||
2cbd95a5 | 356 | static int bpf_adj_delta_to_off(struct bpf_insn *insn, u32 pos, s32 end_old, |
af959b18 | 357 | s32 end_new, s32 curr, const bool probe_pass) |
050fad7c DB |
358 | { |
359 | const s32 off_min = S16_MIN, off_max = S16_MAX; | |
2cbd95a5 | 360 | s32 delta = end_new - end_old; |
050fad7c DB |
361 | s32 off = insn->off; |
362 | ||
2cbd95a5 | 363 | if (curr < pos && curr + off + 1 >= end_old) |
050fad7c | 364 | off += delta; |
2cbd95a5 | 365 | else if (curr >= end_new && curr + off + 1 < end_new) |
050fad7c DB |
366 | off -= delta; |
367 | if (off < off_min || off > off_max) | |
368 | return -ERANGE; | |
369 | if (!probe_pass) | |
370 | insn->off = off; | |
371 | return 0; | |
372 | } | |
373 | ||
2cbd95a5 JK |
374 | static int bpf_adj_branches(struct bpf_prog *prog, u32 pos, s32 end_old, |
375 | s32 end_new, const bool probe_pass) | |
050fad7c | 376 | { |
2cbd95a5 | 377 | u32 i, insn_cnt = prog->len + (probe_pass ? end_new - end_old : 0); |
c237ee5e | 378 | struct bpf_insn *insn = prog->insnsi; |
050fad7c | 379 | int ret = 0; |
c237ee5e DB |
380 | |
381 | for (i = 0; i < insn_cnt; i++, insn++) { | |
050fad7c DB |
382 | u8 code; |
383 | ||
384 | /* In the probing pass we still operate on the original, | |
385 | * unpatched image in order to check overflows before we | |
386 | * do any other adjustments. Therefore skip the patchlet. | |
387 | */ | |
388 | if (probe_pass && i == pos) { | |
2cbd95a5 JK |
389 | i = end_new; |
390 | insn = prog->insnsi + end_old; | |
050fad7c | 391 | } |
1ea47e01 | 392 | code = insn->code; |
092ed096 JW |
393 | if ((BPF_CLASS(code) != BPF_JMP && |
394 | BPF_CLASS(code) != BPF_JMP32) || | |
050fad7c | 395 | BPF_OP(code) == BPF_EXIT) |
1ea47e01 | 396 | continue; |
050fad7c | 397 | /* Adjust offset of jmps if we cross patch boundaries. */ |
1ea47e01 | 398 | if (BPF_OP(code) == BPF_CALL) { |
050fad7c | 399 | if (insn->src_reg != BPF_PSEUDO_CALL) |
1ea47e01 | 400 | continue; |
2cbd95a5 JK |
401 | ret = bpf_adj_delta_to_imm(insn, pos, end_old, |
402 | end_new, i, probe_pass); | |
1ea47e01 | 403 | } else { |
2cbd95a5 JK |
404 | ret = bpf_adj_delta_to_off(insn, pos, end_old, |
405 | end_new, i, probe_pass); | |
1ea47e01 | 406 | } |
050fad7c DB |
407 | if (ret) |
408 | break; | |
c237ee5e | 409 | } |
050fad7c DB |
410 | |
411 | return ret; | |
c237ee5e DB |
412 | } |
413 | ||
c454a46b MKL |
414 | static void bpf_adj_linfo(struct bpf_prog *prog, u32 off, u32 delta) |
415 | { | |
416 | struct bpf_line_info *linfo; | |
417 | u32 i, nr_linfo; | |
418 | ||
419 | nr_linfo = prog->aux->nr_linfo; | |
420 | if (!nr_linfo || !delta) | |
421 | return; | |
422 | ||
423 | linfo = prog->aux->linfo; | |
424 | ||
425 | for (i = 0; i < nr_linfo; i++) | |
426 | if (off < linfo[i].insn_off) | |
427 | break; | |
428 | ||
429 | /* Push all off < linfo[i].insn_off by delta */ | |
430 | for (; i < nr_linfo; i++) | |
431 | linfo[i].insn_off += delta; | |
432 | } | |
433 | ||
c237ee5e DB |
434 | struct bpf_prog *bpf_patch_insn_single(struct bpf_prog *prog, u32 off, |
435 | const struct bpf_insn *patch, u32 len) | |
436 | { | |
437 | u32 insn_adj_cnt, insn_rest, insn_delta = len - 1; | |
050fad7c | 438 | const u32 cnt_max = S16_MAX; |
c237ee5e | 439 | struct bpf_prog *prog_adj; |
4f73379e | 440 | int err; |
c237ee5e DB |
441 | |
442 | /* Since our patchlet doesn't expand the image, we're done. */ | |
443 | if (insn_delta == 0) { | |
444 | memcpy(prog->insnsi + off, patch, sizeof(*patch)); | |
445 | return prog; | |
446 | } | |
447 | ||
448 | insn_adj_cnt = prog->len + insn_delta; | |
449 | ||
050fad7c DB |
450 | /* Reject anything that would potentially let the insn->off |
451 | * target overflow when we have excessive program expansions. | |
452 | * We need to probe here before we do any reallocation where | |
453 | * we afterwards may not fail anymore. | |
454 | */ | |
455 | if (insn_adj_cnt > cnt_max && | |
4f73379e AS |
456 | (err = bpf_adj_branches(prog, off, off + 1, off + len, true))) |
457 | return ERR_PTR(err); | |
050fad7c | 458 | |
c237ee5e DB |
459 | /* Several new instructions need to be inserted. Make room |
460 | * for them. Likely, there's no need for a new allocation as | |
461 | * last page could have large enough tailroom. | |
462 | */ | |
463 | prog_adj = bpf_prog_realloc(prog, bpf_prog_size(insn_adj_cnt), | |
464 | GFP_USER); | |
465 | if (!prog_adj) | |
4f73379e | 466 | return ERR_PTR(-ENOMEM); |
c237ee5e DB |
467 | |
468 | prog_adj->len = insn_adj_cnt; | |
469 | ||
470 | /* Patching happens in 3 steps: | |
471 | * | |
472 | * 1) Move over tail of insnsi from next instruction onwards, | |
473 | * so we can patch the single target insn with one or more | |
474 | * new ones (patching is always from 1 to n insns, n > 0). | |
475 | * 2) Inject new instructions at the target location. | |
476 | * 3) Adjust branch offsets if necessary. | |
477 | */ | |
478 | insn_rest = insn_adj_cnt - off - len; | |
479 | ||
480 | memmove(prog_adj->insnsi + off + len, prog_adj->insnsi + off + 1, | |
481 | sizeof(*patch) * insn_rest); | |
482 | memcpy(prog_adj->insnsi + off, patch, sizeof(*patch) * len); | |
483 | ||
050fad7c DB |
484 | /* We are guaranteed to not fail at this point, otherwise |
485 | * the ship has sailed to reverse to the original state. An | |
486 | * overflow cannot happen at this point. | |
487 | */ | |
2cbd95a5 | 488 | BUG_ON(bpf_adj_branches(prog_adj, off, off + 1, off + len, false)); |
c237ee5e | 489 | |
c454a46b MKL |
490 | bpf_adj_linfo(prog_adj, off, insn_delta); |
491 | ||
c237ee5e DB |
492 | return prog_adj; |
493 | } | |
494 | ||
52875a04 JK |
495 | int bpf_remove_insns(struct bpf_prog *prog, u32 off, u32 cnt) |
496 | { | |
497 | /* Branch offsets can't overflow when program is shrinking, no need | |
498 | * to call bpf_adj_branches(..., true) here | |
499 | */ | |
500 | memmove(prog->insnsi + off, prog->insnsi + off + cnt, | |
501 | sizeof(struct bpf_insn) * (prog->len - off - cnt)); | |
502 | prog->len -= cnt; | |
503 | ||
504 | return WARN_ON_ONCE(bpf_adj_branches(prog, off, off + cnt, off, false)); | |
505 | } | |
506 | ||
cd7455f1 | 507 | static void bpf_prog_kallsyms_del_subprogs(struct bpf_prog *fp) |
7d1982b4 DB |
508 | { |
509 | int i; | |
510 | ||
511 | for (i = 0; i < fp->aux->func_cnt; i++) | |
512 | bpf_prog_kallsyms_del(fp->aux->func[i]); | |
513 | } | |
514 | ||
515 | void bpf_prog_kallsyms_del_all(struct bpf_prog *fp) | |
516 | { | |
517 | bpf_prog_kallsyms_del_subprogs(fp); | |
518 | bpf_prog_kallsyms_del(fp); | |
519 | } | |
520 | ||
b954d834 | 521 | #ifdef CONFIG_BPF_JIT |
fa9dd599 DB |
522 | /* All BPF JIT sysctl knobs here. */ |
523 | int bpf_jit_enable __read_mostly = IS_BUILTIN(CONFIG_BPF_JIT_ALWAYS_ON); | |
524 | int bpf_jit_harden __read_mostly; | |
525 | int bpf_jit_kallsyms __read_mostly; | |
fdadd049 | 526 | long bpf_jit_limit __read_mostly; |
fa9dd599 | 527 | |
74451e66 DB |
528 | static __always_inline void |
529 | bpf_get_prog_addr_region(const struct bpf_prog *prog, | |
530 | unsigned long *symbol_start, | |
531 | unsigned long *symbol_end) | |
532 | { | |
533 | const struct bpf_binary_header *hdr = bpf_jit_binary_hdr(prog); | |
534 | unsigned long addr = (unsigned long)hdr; | |
535 | ||
536 | WARN_ON_ONCE(!bpf_prog_ebpf_jited(prog)); | |
537 | ||
538 | *symbol_start = addr; | |
539 | *symbol_end = addr + hdr->pages * PAGE_SIZE; | |
540 | } | |
541 | ||
6ee52e2a | 542 | void bpf_get_prog_name(const struct bpf_prog *prog, char *sym) |
74451e66 | 543 | { |
368211fb | 544 | const char *end = sym + KSYM_NAME_LEN; |
838e9690 YS |
545 | const struct btf_type *type; |
546 | const char *func_name; | |
368211fb | 547 | |
74451e66 | 548 | BUILD_BUG_ON(sizeof("bpf_prog_") + |
368211fb MKL |
549 | sizeof(prog->tag) * 2 + |
550 | /* name has been null terminated. | |
551 | * We should need +1 for the '_' preceding | |
552 | * the name. However, the null character | |
553 | * is double counted between the name and the | |
554 | * sizeof("bpf_prog_") above, so we omit | |
555 | * the +1 here. | |
556 | */ | |
557 | sizeof(prog->aux->name) > KSYM_NAME_LEN); | |
74451e66 DB |
558 | |
559 | sym += snprintf(sym, KSYM_NAME_LEN, "bpf_prog_"); | |
560 | sym = bin2hex(sym, prog->tag, sizeof(prog->tag)); | |
838e9690 YS |
561 | |
562 | /* prog->aux->name will be ignored if full btf name is available */ | |
7337224f | 563 | if (prog->aux->func_info_cnt) { |
ba64e7d8 YS |
564 | type = btf_type_by_id(prog->aux->btf, |
565 | prog->aux->func_info[prog->aux->func_idx].type_id); | |
838e9690 YS |
566 | func_name = btf_name_by_offset(prog->aux->btf, type->name_off); |
567 | snprintf(sym, (size_t)(end - sym), "_%s", func_name); | |
568 | return; | |
569 | } | |
570 | ||
368211fb MKL |
571 | if (prog->aux->name[0]) |
572 | snprintf(sym, (size_t)(end - sym), "_%s", prog->aux->name); | |
573 | else | |
574 | *sym = 0; | |
74451e66 DB |
575 | } |
576 | ||
577 | static __always_inline unsigned long | |
578 | bpf_get_prog_addr_start(struct latch_tree_node *n) | |
579 | { | |
580 | unsigned long symbol_start, symbol_end; | |
581 | const struct bpf_prog_aux *aux; | |
582 | ||
583 | aux = container_of(n, struct bpf_prog_aux, ksym_tnode); | |
584 | bpf_get_prog_addr_region(aux->prog, &symbol_start, &symbol_end); | |
585 | ||
586 | return symbol_start; | |
587 | } | |
588 | ||
589 | static __always_inline bool bpf_tree_less(struct latch_tree_node *a, | |
590 | struct latch_tree_node *b) | |
591 | { | |
592 | return bpf_get_prog_addr_start(a) < bpf_get_prog_addr_start(b); | |
593 | } | |
594 | ||
595 | static __always_inline int bpf_tree_comp(void *key, struct latch_tree_node *n) | |
596 | { | |
597 | unsigned long val = (unsigned long)key; | |
598 | unsigned long symbol_start, symbol_end; | |
599 | const struct bpf_prog_aux *aux; | |
600 | ||
601 | aux = container_of(n, struct bpf_prog_aux, ksym_tnode); | |
602 | bpf_get_prog_addr_region(aux->prog, &symbol_start, &symbol_end); | |
603 | ||
604 | if (val < symbol_start) | |
605 | return -1; | |
606 | if (val >= symbol_end) | |
607 | return 1; | |
608 | ||
609 | return 0; | |
610 | } | |
611 | ||
612 | static const struct latch_tree_ops bpf_tree_ops = { | |
613 | .less = bpf_tree_less, | |
614 | .comp = bpf_tree_comp, | |
615 | }; | |
616 | ||
617 | static DEFINE_SPINLOCK(bpf_lock); | |
618 | static LIST_HEAD(bpf_kallsyms); | |
619 | static struct latch_tree_root bpf_tree __cacheline_aligned; | |
620 | ||
74451e66 DB |
621 | static void bpf_prog_ksym_node_add(struct bpf_prog_aux *aux) |
622 | { | |
623 | WARN_ON_ONCE(!list_empty(&aux->ksym_lnode)); | |
624 | list_add_tail_rcu(&aux->ksym_lnode, &bpf_kallsyms); | |
625 | latch_tree_insert(&aux->ksym_tnode, &bpf_tree, &bpf_tree_ops); | |
626 | } | |
627 | ||
628 | static void bpf_prog_ksym_node_del(struct bpf_prog_aux *aux) | |
629 | { | |
630 | if (list_empty(&aux->ksym_lnode)) | |
631 | return; | |
632 | ||
633 | latch_tree_erase(&aux->ksym_tnode, &bpf_tree, &bpf_tree_ops); | |
634 | list_del_rcu(&aux->ksym_lnode); | |
635 | } | |
636 | ||
637 | static bool bpf_prog_kallsyms_candidate(const struct bpf_prog *fp) | |
638 | { | |
639 | return fp->jited && !bpf_prog_was_classic(fp); | |
640 | } | |
641 | ||
642 | static bool bpf_prog_kallsyms_verify_off(const struct bpf_prog *fp) | |
643 | { | |
644 | return list_empty(&fp->aux->ksym_lnode) || | |
645 | fp->aux->ksym_lnode.prev == LIST_POISON2; | |
646 | } | |
647 | ||
648 | void bpf_prog_kallsyms_add(struct bpf_prog *fp) | |
649 | { | |
74451e66 DB |
650 | if (!bpf_prog_kallsyms_candidate(fp) || |
651 | !capable(CAP_SYS_ADMIN)) | |
652 | return; | |
653 | ||
d24f7c7f | 654 | spin_lock_bh(&bpf_lock); |
74451e66 | 655 | bpf_prog_ksym_node_add(fp->aux); |
d24f7c7f | 656 | spin_unlock_bh(&bpf_lock); |
74451e66 DB |
657 | } |
658 | ||
659 | void bpf_prog_kallsyms_del(struct bpf_prog *fp) | |
660 | { | |
74451e66 DB |
661 | if (!bpf_prog_kallsyms_candidate(fp)) |
662 | return; | |
663 | ||
d24f7c7f | 664 | spin_lock_bh(&bpf_lock); |
74451e66 | 665 | bpf_prog_ksym_node_del(fp->aux); |
d24f7c7f | 666 | spin_unlock_bh(&bpf_lock); |
74451e66 DB |
667 | } |
668 | ||
669 | static struct bpf_prog *bpf_prog_kallsyms_find(unsigned long addr) | |
670 | { | |
671 | struct latch_tree_node *n; | |
672 | ||
74451e66 DB |
673 | n = latch_tree_find((void *)addr, &bpf_tree, &bpf_tree_ops); |
674 | return n ? | |
675 | container_of(n, struct bpf_prog_aux, ksym_tnode)->prog : | |
676 | NULL; | |
677 | } | |
678 | ||
679 | const char *__bpf_address_lookup(unsigned long addr, unsigned long *size, | |
680 | unsigned long *off, char *sym) | |
681 | { | |
682 | unsigned long symbol_start, symbol_end; | |
683 | struct bpf_prog *prog; | |
684 | char *ret = NULL; | |
685 | ||
686 | rcu_read_lock(); | |
687 | prog = bpf_prog_kallsyms_find(addr); | |
688 | if (prog) { | |
689 | bpf_get_prog_addr_region(prog, &symbol_start, &symbol_end); | |
690 | bpf_get_prog_name(prog, sym); | |
691 | ||
692 | ret = sym; | |
693 | if (size) | |
694 | *size = symbol_end - symbol_start; | |
695 | if (off) | |
696 | *off = addr - symbol_start; | |
697 | } | |
698 | rcu_read_unlock(); | |
699 | ||
700 | return ret; | |
701 | } | |
702 | ||
703 | bool is_bpf_text_address(unsigned long addr) | |
704 | { | |
705 | bool ret; | |
706 | ||
707 | rcu_read_lock(); | |
708 | ret = bpf_prog_kallsyms_find(addr) != NULL; | |
709 | rcu_read_unlock(); | |
710 | ||
711 | return ret; | |
712 | } | |
713 | ||
3dec541b AS |
714 | const struct exception_table_entry *search_bpf_extables(unsigned long addr) |
715 | { | |
716 | const struct exception_table_entry *e = NULL; | |
717 | struct bpf_prog *prog; | |
718 | ||
719 | rcu_read_lock(); | |
720 | prog = bpf_prog_kallsyms_find(addr); | |
721 | if (!prog) | |
722 | goto out; | |
723 | if (!prog->aux->num_exentries) | |
724 | goto out; | |
725 | ||
726 | e = search_extable(prog->aux->extable, prog->aux->num_exentries, addr); | |
727 | out: | |
728 | rcu_read_unlock(); | |
729 | return e; | |
730 | } | |
731 | ||
74451e66 DB |
732 | int bpf_get_kallsym(unsigned int symnum, unsigned long *value, char *type, |
733 | char *sym) | |
734 | { | |
74451e66 DB |
735 | struct bpf_prog_aux *aux; |
736 | unsigned int it = 0; | |
737 | int ret = -ERANGE; | |
738 | ||
739 | if (!bpf_jit_kallsyms_enabled()) | |
740 | return ret; | |
741 | ||
742 | rcu_read_lock(); | |
743 | list_for_each_entry_rcu(aux, &bpf_kallsyms, ksym_lnode) { | |
744 | if (it++ != symnum) | |
745 | continue; | |
746 | ||
74451e66 DB |
747 | bpf_get_prog_name(aux->prog, sym); |
748 | ||
df073470 | 749 | *value = (unsigned long)aux->prog->bpf_func; |
74451e66 DB |
750 | *type = BPF_SYM_ELF_TYPE; |
751 | ||
752 | ret = 0; | |
753 | break; | |
754 | } | |
755 | rcu_read_unlock(); | |
756 | ||
757 | return ret; | |
758 | } | |
759 | ||
a66886fe DB |
760 | int bpf_jit_add_poke_descriptor(struct bpf_prog *prog, |
761 | struct bpf_jit_poke_descriptor *poke) | |
762 | { | |
763 | struct bpf_jit_poke_descriptor *tab = prog->aux->poke_tab; | |
764 | static const u32 poke_tab_max = 1024; | |
765 | u32 slot = prog->aux->size_poke_tab; | |
766 | u32 size = slot + 1; | |
767 | ||
768 | if (size > poke_tab_max) | |
769 | return -ENOSPC; | |
770 | if (poke->ip || poke->ip_stable || poke->adj_off) | |
771 | return -EINVAL; | |
772 | ||
773 | switch (poke->reason) { | |
774 | case BPF_POKE_REASON_TAIL_CALL: | |
775 | if (!poke->tail_call.map) | |
776 | return -EINVAL; | |
777 | break; | |
778 | default: | |
779 | return -EINVAL; | |
780 | } | |
781 | ||
782 | tab = krealloc(tab, size * sizeof(*poke), GFP_KERNEL); | |
783 | if (!tab) | |
784 | return -ENOMEM; | |
785 | ||
786 | memcpy(&tab[slot], poke, sizeof(*poke)); | |
787 | prog->aux->size_poke_tab = size; | |
788 | prog->aux->poke_tab = tab; | |
789 | ||
790 | return slot; | |
791 | } | |
792 | ||
ede95a63 DB |
793 | static atomic_long_t bpf_jit_current; |
794 | ||
fdadd049 DB |
795 | /* Can be overridden by an arch's JIT compiler if it has a custom, |
796 | * dedicated BPF backend memory area, or if neither of the two | |
797 | * below apply. | |
798 | */ | |
799 | u64 __weak bpf_jit_alloc_exec_limit(void) | |
800 | { | |
ede95a63 | 801 | #if defined(MODULES_VADDR) |
fdadd049 DB |
802 | return MODULES_END - MODULES_VADDR; |
803 | #else | |
804 | return VMALLOC_END - VMALLOC_START; | |
805 | #endif | |
806 | } | |
807 | ||
ede95a63 DB |
808 | static int __init bpf_jit_charge_init(void) |
809 | { | |
810 | /* Only used as heuristic here to derive limit. */ | |
fdadd049 DB |
811 | bpf_jit_limit = min_t(u64, round_up(bpf_jit_alloc_exec_limit() >> 2, |
812 | PAGE_SIZE), LONG_MAX); | |
ede95a63 DB |
813 | return 0; |
814 | } | |
815 | pure_initcall(bpf_jit_charge_init); | |
ede95a63 DB |
816 | |
817 | static int bpf_jit_charge_modmem(u32 pages) | |
818 | { | |
819 | if (atomic_long_add_return(pages, &bpf_jit_current) > | |
820 | (bpf_jit_limit >> PAGE_SHIFT)) { | |
821 | if (!capable(CAP_SYS_ADMIN)) { | |
822 | atomic_long_sub(pages, &bpf_jit_current); | |
823 | return -EPERM; | |
824 | } | |
825 | } | |
826 | ||
827 | return 0; | |
828 | } | |
829 | ||
830 | static void bpf_jit_uncharge_modmem(u32 pages) | |
831 | { | |
832 | atomic_long_sub(pages, &bpf_jit_current); | |
833 | } | |
834 | ||
dc002bb6 AB |
835 | void *__weak bpf_jit_alloc_exec(unsigned long size) |
836 | { | |
837 | return module_alloc(size); | |
838 | } | |
839 | ||
840 | void __weak bpf_jit_free_exec(void *addr) | |
841 | { | |
842 | module_memfree(addr); | |
843 | } | |
844 | ||
738cbe72 DB |
845 | struct bpf_binary_header * |
846 | bpf_jit_binary_alloc(unsigned int proglen, u8 **image_ptr, | |
847 | unsigned int alignment, | |
848 | bpf_jit_fill_hole_t bpf_fill_ill_insns) | |
849 | { | |
850 | struct bpf_binary_header *hdr; | |
ede95a63 | 851 | u32 size, hole, start, pages; |
738cbe72 | 852 | |
b7b3fc8d IL |
853 | WARN_ON_ONCE(!is_power_of_2(alignment) || |
854 | alignment > BPF_IMAGE_ALIGNMENT); | |
855 | ||
738cbe72 DB |
856 | /* Most of BPF filters are really small, but if some of them |
857 | * fill a page, allow at least 128 extra bytes to insert a | |
858 | * random section of illegal instructions. | |
859 | */ | |
860 | size = round_up(proglen + sizeof(*hdr) + 128, PAGE_SIZE); | |
ede95a63 DB |
861 | pages = size / PAGE_SIZE; |
862 | ||
863 | if (bpf_jit_charge_modmem(pages)) | |
864 | return NULL; | |
dc002bb6 | 865 | hdr = bpf_jit_alloc_exec(size); |
ede95a63 DB |
866 | if (!hdr) { |
867 | bpf_jit_uncharge_modmem(pages); | |
738cbe72 | 868 | return NULL; |
ede95a63 | 869 | } |
738cbe72 DB |
870 | |
871 | /* Fill space with illegal/arch-dep instructions. */ | |
872 | bpf_fill_ill_insns(hdr, size); | |
873 | ||
ede95a63 | 874 | hdr->pages = pages; |
738cbe72 DB |
875 | hole = min_t(unsigned int, size - (proglen + sizeof(*hdr)), |
876 | PAGE_SIZE - sizeof(*hdr)); | |
b7552e1b | 877 | start = (get_random_int() % hole) & ~(alignment - 1); |
738cbe72 DB |
878 | |
879 | /* Leave a random number of instructions before BPF code. */ | |
880 | *image_ptr = &hdr->image[start]; | |
881 | ||
882 | return hdr; | |
883 | } | |
884 | ||
885 | void bpf_jit_binary_free(struct bpf_binary_header *hdr) | |
886 | { | |
ede95a63 DB |
887 | u32 pages = hdr->pages; |
888 | ||
dc002bb6 | 889 | bpf_jit_free_exec(hdr); |
ede95a63 | 890 | bpf_jit_uncharge_modmem(pages); |
738cbe72 | 891 | } |
4f3446bb | 892 | |
74451e66 DB |
893 | /* This symbol is only overridden by archs that have different |
894 | * requirements than the usual eBPF JITs, f.e. when they only | |
895 | * implement cBPF JIT, do not set images read-only, etc. | |
896 | */ | |
897 | void __weak bpf_jit_free(struct bpf_prog *fp) | |
898 | { | |
899 | if (fp->jited) { | |
900 | struct bpf_binary_header *hdr = bpf_jit_binary_hdr(fp); | |
901 | ||
74451e66 DB |
902 | bpf_jit_binary_free(hdr); |
903 | ||
904 | WARN_ON_ONCE(!bpf_prog_kallsyms_verify_off(fp)); | |
905 | } | |
906 | ||
907 | bpf_prog_unlock_free(fp); | |
908 | } | |
909 | ||
e2c95a61 DB |
910 | int bpf_jit_get_func_addr(const struct bpf_prog *prog, |
911 | const struct bpf_insn *insn, bool extra_pass, | |
912 | u64 *func_addr, bool *func_addr_fixed) | |
913 | { | |
914 | s16 off = insn->off; | |
915 | s32 imm = insn->imm; | |
916 | u8 *addr; | |
917 | ||
918 | *func_addr_fixed = insn->src_reg != BPF_PSEUDO_CALL; | |
919 | if (!*func_addr_fixed) { | |
920 | /* Place-holder address till the last pass has collected | |
921 | * all addresses for JITed subprograms in which case we | |
922 | * can pick them up from prog->aux. | |
923 | */ | |
924 | if (!extra_pass) | |
925 | addr = NULL; | |
926 | else if (prog->aux->func && | |
927 | off >= 0 && off < prog->aux->func_cnt) | |
928 | addr = (u8 *)prog->aux->func[off]->bpf_func; | |
929 | else | |
930 | return -EINVAL; | |
931 | } else { | |
932 | /* Address of a BPF helper call. Since part of the core | |
933 | * kernel, it's always at a fixed location. __bpf_call_base | |
934 | * and the helper with imm relative to it are both in core | |
935 | * kernel. | |
936 | */ | |
937 | addr = (u8 *)__bpf_call_base + imm; | |
938 | } | |
939 | ||
940 | *func_addr = (unsigned long)addr; | |
941 | return 0; | |
942 | } | |
943 | ||
4f3446bb DB |
944 | static int bpf_jit_blind_insn(const struct bpf_insn *from, |
945 | const struct bpf_insn *aux, | |
ede7c460 NR |
946 | struct bpf_insn *to_buff, |
947 | bool emit_zext) | |
4f3446bb DB |
948 | { |
949 | struct bpf_insn *to = to_buff; | |
b7552e1b | 950 | u32 imm_rnd = get_random_int(); |
4f3446bb DB |
951 | s16 off; |
952 | ||
953 | BUILD_BUG_ON(BPF_REG_AX + 1 != MAX_BPF_JIT_REG); | |
954 | BUILD_BUG_ON(MAX_BPF_REG + 1 != MAX_BPF_JIT_REG); | |
955 | ||
9b73bfdd DB |
956 | /* Constraints on AX register: |
957 | * | |
958 | * AX register is inaccessible from user space. It is mapped in | |
959 | * all JITs, and used here for constant blinding rewrites. It is | |
960 | * typically "stateless" meaning its contents are only valid within | |
961 | * the executed instruction, but not across several instructions. | |
962 | * There are a few exceptions however which are further detailed | |
963 | * below. | |
964 | * | |
965 | * Constant blinding is only used by JITs, not in the interpreter. | |
966 | * The interpreter uses AX in some occasions as a local temporary | |
967 | * register e.g. in DIV or MOD instructions. | |
968 | * | |
969 | * In restricted circumstances, the verifier can also use the AX | |
970 | * register for rewrites as long as they do not interfere with | |
971 | * the above cases! | |
972 | */ | |
973 | if (from->dst_reg == BPF_REG_AX || from->src_reg == BPF_REG_AX) | |
974 | goto out; | |
975 | ||
4f3446bb DB |
976 | if (from->imm == 0 && |
977 | (from->code == (BPF_ALU | BPF_MOV | BPF_K) || | |
978 | from->code == (BPF_ALU64 | BPF_MOV | BPF_K))) { | |
979 | *to++ = BPF_ALU64_REG(BPF_XOR, from->dst_reg, from->dst_reg); | |
980 | goto out; | |
981 | } | |
982 | ||
983 | switch (from->code) { | |
984 | case BPF_ALU | BPF_ADD | BPF_K: | |
985 | case BPF_ALU | BPF_SUB | BPF_K: | |
986 | case BPF_ALU | BPF_AND | BPF_K: | |
987 | case BPF_ALU | BPF_OR | BPF_K: | |
988 | case BPF_ALU | BPF_XOR | BPF_K: | |
989 | case BPF_ALU | BPF_MUL | BPF_K: | |
990 | case BPF_ALU | BPF_MOV | BPF_K: | |
991 | case BPF_ALU | BPF_DIV | BPF_K: | |
992 | case BPF_ALU | BPF_MOD | BPF_K: | |
993 | *to++ = BPF_ALU32_IMM(BPF_MOV, BPF_REG_AX, imm_rnd ^ from->imm); | |
994 | *to++ = BPF_ALU32_IMM(BPF_XOR, BPF_REG_AX, imm_rnd); | |
995 | *to++ = BPF_ALU32_REG(from->code, from->dst_reg, BPF_REG_AX); | |
996 | break; | |
997 | ||
998 | case BPF_ALU64 | BPF_ADD | BPF_K: | |
999 | case BPF_ALU64 | BPF_SUB | BPF_K: | |
1000 | case BPF_ALU64 | BPF_AND | BPF_K: | |
1001 | case BPF_ALU64 | BPF_OR | BPF_K: | |
1002 | case BPF_ALU64 | BPF_XOR | BPF_K: | |
1003 | case BPF_ALU64 | BPF_MUL | BPF_K: | |
1004 | case BPF_ALU64 | BPF_MOV | BPF_K: | |
1005 | case BPF_ALU64 | BPF_DIV | BPF_K: | |
1006 | case BPF_ALU64 | BPF_MOD | BPF_K: | |
1007 | *to++ = BPF_ALU64_IMM(BPF_MOV, BPF_REG_AX, imm_rnd ^ from->imm); | |
1008 | *to++ = BPF_ALU64_IMM(BPF_XOR, BPF_REG_AX, imm_rnd); | |
1009 | *to++ = BPF_ALU64_REG(from->code, from->dst_reg, BPF_REG_AX); | |
1010 | break; | |
1011 | ||
1012 | case BPF_JMP | BPF_JEQ | BPF_K: | |
1013 | case BPF_JMP | BPF_JNE | BPF_K: | |
1014 | case BPF_JMP | BPF_JGT | BPF_K: | |
92b31a9a | 1015 | case BPF_JMP | BPF_JLT | BPF_K: |
4f3446bb | 1016 | case BPF_JMP | BPF_JGE | BPF_K: |
92b31a9a | 1017 | case BPF_JMP | BPF_JLE | BPF_K: |
4f3446bb | 1018 | case BPF_JMP | BPF_JSGT | BPF_K: |
92b31a9a | 1019 | case BPF_JMP | BPF_JSLT | BPF_K: |
4f3446bb | 1020 | case BPF_JMP | BPF_JSGE | BPF_K: |
92b31a9a | 1021 | case BPF_JMP | BPF_JSLE | BPF_K: |
4f3446bb DB |
1022 | case BPF_JMP | BPF_JSET | BPF_K: |
1023 | /* Accommodate for extra offset in case of a backjump. */ | |
1024 | off = from->off; | |
1025 | if (off < 0) | |
1026 | off -= 2; | |
1027 | *to++ = BPF_ALU64_IMM(BPF_MOV, BPF_REG_AX, imm_rnd ^ from->imm); | |
1028 | *to++ = BPF_ALU64_IMM(BPF_XOR, BPF_REG_AX, imm_rnd); | |
1029 | *to++ = BPF_JMP_REG(from->code, from->dst_reg, BPF_REG_AX, off); | |
1030 | break; | |
1031 | ||
a7b76c88 JW |
1032 | case BPF_JMP32 | BPF_JEQ | BPF_K: |
1033 | case BPF_JMP32 | BPF_JNE | BPF_K: | |
1034 | case BPF_JMP32 | BPF_JGT | BPF_K: | |
1035 | case BPF_JMP32 | BPF_JLT | BPF_K: | |
1036 | case BPF_JMP32 | BPF_JGE | BPF_K: | |
1037 | case BPF_JMP32 | BPF_JLE | BPF_K: | |
1038 | case BPF_JMP32 | BPF_JSGT | BPF_K: | |
1039 | case BPF_JMP32 | BPF_JSLT | BPF_K: | |
1040 | case BPF_JMP32 | BPF_JSGE | BPF_K: | |
1041 | case BPF_JMP32 | BPF_JSLE | BPF_K: | |
1042 | case BPF_JMP32 | BPF_JSET | BPF_K: | |
1043 | /* Accommodate for extra offset in case of a backjump. */ | |
1044 | off = from->off; | |
1045 | if (off < 0) | |
1046 | off -= 2; | |
1047 | *to++ = BPF_ALU32_IMM(BPF_MOV, BPF_REG_AX, imm_rnd ^ from->imm); | |
1048 | *to++ = BPF_ALU32_IMM(BPF_XOR, BPF_REG_AX, imm_rnd); | |
1049 | *to++ = BPF_JMP32_REG(from->code, from->dst_reg, BPF_REG_AX, | |
1050 | off); | |
1051 | break; | |
1052 | ||
4f3446bb DB |
1053 | case BPF_LD | BPF_IMM | BPF_DW: |
1054 | *to++ = BPF_ALU64_IMM(BPF_MOV, BPF_REG_AX, imm_rnd ^ aux[1].imm); | |
1055 | *to++ = BPF_ALU64_IMM(BPF_XOR, BPF_REG_AX, imm_rnd); | |
1056 | *to++ = BPF_ALU64_IMM(BPF_LSH, BPF_REG_AX, 32); | |
1057 | *to++ = BPF_ALU64_REG(BPF_MOV, aux[0].dst_reg, BPF_REG_AX); | |
1058 | break; | |
1059 | case 0: /* Part 2 of BPF_LD | BPF_IMM | BPF_DW. */ | |
1060 | *to++ = BPF_ALU32_IMM(BPF_MOV, BPF_REG_AX, imm_rnd ^ aux[0].imm); | |
1061 | *to++ = BPF_ALU32_IMM(BPF_XOR, BPF_REG_AX, imm_rnd); | |
ede7c460 NR |
1062 | if (emit_zext) |
1063 | *to++ = BPF_ZEXT_REG(BPF_REG_AX); | |
4f3446bb DB |
1064 | *to++ = BPF_ALU64_REG(BPF_OR, aux[0].dst_reg, BPF_REG_AX); |
1065 | break; | |
1066 | ||
1067 | case BPF_ST | BPF_MEM | BPF_DW: | |
1068 | case BPF_ST | BPF_MEM | BPF_W: | |
1069 | case BPF_ST | BPF_MEM | BPF_H: | |
1070 | case BPF_ST | BPF_MEM | BPF_B: | |
1071 | *to++ = BPF_ALU64_IMM(BPF_MOV, BPF_REG_AX, imm_rnd ^ from->imm); | |
1072 | *to++ = BPF_ALU64_IMM(BPF_XOR, BPF_REG_AX, imm_rnd); | |
1073 | *to++ = BPF_STX_MEM(from->code, from->dst_reg, BPF_REG_AX, from->off); | |
1074 | break; | |
1075 | } | |
1076 | out: | |
1077 | return to - to_buff; | |
1078 | } | |
1079 | ||
1080 | static struct bpf_prog *bpf_prog_clone_create(struct bpf_prog *fp_other, | |
1081 | gfp_t gfp_extra_flags) | |
1082 | { | |
19809c2d | 1083 | gfp_t gfp_flags = GFP_KERNEL | __GFP_ZERO | gfp_extra_flags; |
4f3446bb DB |
1084 | struct bpf_prog *fp; |
1085 | ||
1086 | fp = __vmalloc(fp_other->pages * PAGE_SIZE, gfp_flags, PAGE_KERNEL); | |
1087 | if (fp != NULL) { | |
4f3446bb DB |
1088 | /* aux->prog still points to the fp_other one, so |
1089 | * when promoting the clone to the real program, | |
1090 | * this still needs to be adapted. | |
1091 | */ | |
1092 | memcpy(fp, fp_other, fp_other->pages * PAGE_SIZE); | |
1093 | } | |
1094 | ||
1095 | return fp; | |
1096 | } | |
1097 | ||
1098 | static void bpf_prog_clone_free(struct bpf_prog *fp) | |
1099 | { | |
1100 | /* aux was stolen by the other clone, so we cannot free | |
1101 | * it from this path! It will be freed eventually by the | |
1102 | * other program on release. | |
1103 | * | |
1104 | * At this point, we don't need a deferred release since | |
1105 | * clone is guaranteed to not be locked. | |
1106 | */ | |
1107 | fp->aux = NULL; | |
1108 | __bpf_prog_free(fp); | |
1109 | } | |
1110 | ||
1111 | void bpf_jit_prog_release_other(struct bpf_prog *fp, struct bpf_prog *fp_other) | |
1112 | { | |
1113 | /* We have to repoint aux->prog to self, as we don't | |
1114 | * know whether fp here is the clone or the original. | |
1115 | */ | |
1116 | fp->aux->prog = fp; | |
1117 | bpf_prog_clone_free(fp_other); | |
1118 | } | |
1119 | ||
1120 | struct bpf_prog *bpf_jit_blind_constants(struct bpf_prog *prog) | |
1121 | { | |
1122 | struct bpf_insn insn_buff[16], aux[2]; | |
1123 | struct bpf_prog *clone, *tmp; | |
1124 | int insn_delta, insn_cnt; | |
1125 | struct bpf_insn *insn; | |
1126 | int i, rewritten; | |
1127 | ||
1c2a088a | 1128 | if (!bpf_jit_blinding_enabled(prog) || prog->blinded) |
4f3446bb DB |
1129 | return prog; |
1130 | ||
1131 | clone = bpf_prog_clone_create(prog, GFP_USER); | |
1132 | if (!clone) | |
1133 | return ERR_PTR(-ENOMEM); | |
1134 | ||
1135 | insn_cnt = clone->len; | |
1136 | insn = clone->insnsi; | |
1137 | ||
1138 | for (i = 0; i < insn_cnt; i++, insn++) { | |
1139 | /* We temporarily need to hold the original ld64 insn | |
1140 | * so that we can still access the first part in the | |
1141 | * second blinding run. | |
1142 | */ | |
1143 | if (insn[0].code == (BPF_LD | BPF_IMM | BPF_DW) && | |
1144 | insn[1].code == 0) | |
1145 | memcpy(aux, insn, sizeof(aux)); | |
1146 | ||
ede7c460 NR |
1147 | rewritten = bpf_jit_blind_insn(insn, aux, insn_buff, |
1148 | clone->aux->verifier_zext); | |
4f3446bb DB |
1149 | if (!rewritten) |
1150 | continue; | |
1151 | ||
1152 | tmp = bpf_patch_insn_single(clone, i, insn_buff, rewritten); | |
4f73379e | 1153 | if (IS_ERR(tmp)) { |
4f3446bb DB |
1154 | /* Patching may have repointed aux->prog during |
1155 | * realloc from the original one, so we need to | |
1156 | * fix it up here on error. | |
1157 | */ | |
1158 | bpf_jit_prog_release_other(prog, clone); | |
4f73379e | 1159 | return tmp; |
4f3446bb DB |
1160 | } |
1161 | ||
1162 | clone = tmp; | |
1163 | insn_delta = rewritten - 1; | |
1164 | ||
1165 | /* Walk new program and skip insns we just inserted. */ | |
1166 | insn = clone->insnsi + i + insn_delta; | |
1167 | insn_cnt += insn_delta; | |
1168 | i += insn_delta; | |
1169 | } | |
1170 | ||
1c2a088a | 1171 | clone->blinded = 1; |
4f3446bb DB |
1172 | return clone; |
1173 | } | |
b954d834 | 1174 | #endif /* CONFIG_BPF_JIT */ |
738cbe72 | 1175 | |
f5bffecd AS |
1176 | /* Base function for offset calculation. Needs to go into .text section, |
1177 | * therefore keeping it non-static as well; will also be used by JITs | |
7105e828 DB |
1178 | * anyway later on, so do not let the compiler omit it. This also needs |
1179 | * to go into kallsyms for correlation from e.g. bpftool, so naming | |
1180 | * must not change. | |
f5bffecd AS |
1181 | */ |
1182 | noinline u64 __bpf_call_base(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5) | |
1183 | { | |
1184 | return 0; | |
1185 | } | |
4d9c5c53 | 1186 | EXPORT_SYMBOL_GPL(__bpf_call_base); |
f5bffecd | 1187 | |
5e581dad DB |
1188 | /* All UAPI available opcodes. */ |
1189 | #define BPF_INSN_MAP(INSN_2, INSN_3) \ | |
1190 | /* 32 bit ALU operations. */ \ | |
1191 | /* Register based. */ \ | |
2dc6b100 JW |
1192 | INSN_3(ALU, ADD, X), \ |
1193 | INSN_3(ALU, SUB, X), \ | |
1194 | INSN_3(ALU, AND, X), \ | |
1195 | INSN_3(ALU, OR, X), \ | |
1196 | INSN_3(ALU, LSH, X), \ | |
1197 | INSN_3(ALU, RSH, X), \ | |
1198 | INSN_3(ALU, XOR, X), \ | |
1199 | INSN_3(ALU, MUL, X), \ | |
1200 | INSN_3(ALU, MOV, X), \ | |
1201 | INSN_3(ALU, ARSH, X), \ | |
1202 | INSN_3(ALU, DIV, X), \ | |
1203 | INSN_3(ALU, MOD, X), \ | |
5e581dad DB |
1204 | INSN_2(ALU, NEG), \ |
1205 | INSN_3(ALU, END, TO_BE), \ | |
1206 | INSN_3(ALU, END, TO_LE), \ | |
1207 | /* Immediate based. */ \ | |
2dc6b100 JW |
1208 | INSN_3(ALU, ADD, K), \ |
1209 | INSN_3(ALU, SUB, K), \ | |
1210 | INSN_3(ALU, AND, K), \ | |
1211 | INSN_3(ALU, OR, K), \ | |
1212 | INSN_3(ALU, LSH, K), \ | |
1213 | INSN_3(ALU, RSH, K), \ | |
1214 | INSN_3(ALU, XOR, K), \ | |
1215 | INSN_3(ALU, MUL, K), \ | |
1216 | INSN_3(ALU, MOV, K), \ | |
1217 | INSN_3(ALU, ARSH, K), \ | |
1218 | INSN_3(ALU, DIV, K), \ | |
1219 | INSN_3(ALU, MOD, K), \ | |
5e581dad DB |
1220 | /* 64 bit ALU operations. */ \ |
1221 | /* Register based. */ \ | |
1222 | INSN_3(ALU64, ADD, X), \ | |
1223 | INSN_3(ALU64, SUB, X), \ | |
1224 | INSN_3(ALU64, AND, X), \ | |
1225 | INSN_3(ALU64, OR, X), \ | |
1226 | INSN_3(ALU64, LSH, X), \ | |
1227 | INSN_3(ALU64, RSH, X), \ | |
1228 | INSN_3(ALU64, XOR, X), \ | |
1229 | INSN_3(ALU64, MUL, X), \ | |
1230 | INSN_3(ALU64, MOV, X), \ | |
1231 | INSN_3(ALU64, ARSH, X), \ | |
1232 | INSN_3(ALU64, DIV, X), \ | |
1233 | INSN_3(ALU64, MOD, X), \ | |
1234 | INSN_2(ALU64, NEG), \ | |
1235 | /* Immediate based. */ \ | |
1236 | INSN_3(ALU64, ADD, K), \ | |
1237 | INSN_3(ALU64, SUB, K), \ | |
1238 | INSN_3(ALU64, AND, K), \ | |
1239 | INSN_3(ALU64, OR, K), \ | |
1240 | INSN_3(ALU64, LSH, K), \ | |
1241 | INSN_3(ALU64, RSH, K), \ | |
1242 | INSN_3(ALU64, XOR, K), \ | |
1243 | INSN_3(ALU64, MUL, K), \ | |
1244 | INSN_3(ALU64, MOV, K), \ | |
1245 | INSN_3(ALU64, ARSH, K), \ | |
1246 | INSN_3(ALU64, DIV, K), \ | |
1247 | INSN_3(ALU64, MOD, K), \ | |
1248 | /* Call instruction. */ \ | |
1249 | INSN_2(JMP, CALL), \ | |
1250 | /* Exit instruction. */ \ | |
1251 | INSN_2(JMP, EXIT), \ | |
503a8865 JW |
1252 | /* 32-bit Jump instructions. */ \ |
1253 | /* Register based. */ \ | |
1254 | INSN_3(JMP32, JEQ, X), \ | |
1255 | INSN_3(JMP32, JNE, X), \ | |
1256 | INSN_3(JMP32, JGT, X), \ | |
1257 | INSN_3(JMP32, JLT, X), \ | |
1258 | INSN_3(JMP32, JGE, X), \ | |
1259 | INSN_3(JMP32, JLE, X), \ | |
1260 | INSN_3(JMP32, JSGT, X), \ | |
1261 | INSN_3(JMP32, JSLT, X), \ | |
1262 | INSN_3(JMP32, JSGE, X), \ | |
1263 | INSN_3(JMP32, JSLE, X), \ | |
1264 | INSN_3(JMP32, JSET, X), \ | |
1265 | /* Immediate based. */ \ | |
1266 | INSN_3(JMP32, JEQ, K), \ | |
1267 | INSN_3(JMP32, JNE, K), \ | |
1268 | INSN_3(JMP32, JGT, K), \ | |
1269 | INSN_3(JMP32, JLT, K), \ | |
1270 | INSN_3(JMP32, JGE, K), \ | |
1271 | INSN_3(JMP32, JLE, K), \ | |
1272 | INSN_3(JMP32, JSGT, K), \ | |
1273 | INSN_3(JMP32, JSLT, K), \ | |
1274 | INSN_3(JMP32, JSGE, K), \ | |
1275 | INSN_3(JMP32, JSLE, K), \ | |
1276 | INSN_3(JMP32, JSET, K), \ | |
5e581dad DB |
1277 | /* Jump instructions. */ \ |
1278 | /* Register based. */ \ | |
1279 | INSN_3(JMP, JEQ, X), \ | |
1280 | INSN_3(JMP, JNE, X), \ | |
1281 | INSN_3(JMP, JGT, X), \ | |
1282 | INSN_3(JMP, JLT, X), \ | |
1283 | INSN_3(JMP, JGE, X), \ | |
1284 | INSN_3(JMP, JLE, X), \ | |
1285 | INSN_3(JMP, JSGT, X), \ | |
1286 | INSN_3(JMP, JSLT, X), \ | |
1287 | INSN_3(JMP, JSGE, X), \ | |
1288 | INSN_3(JMP, JSLE, X), \ | |
1289 | INSN_3(JMP, JSET, X), \ | |
1290 | /* Immediate based. */ \ | |
1291 | INSN_3(JMP, JEQ, K), \ | |
1292 | INSN_3(JMP, JNE, K), \ | |
1293 | INSN_3(JMP, JGT, K), \ | |
1294 | INSN_3(JMP, JLT, K), \ | |
1295 | INSN_3(JMP, JGE, K), \ | |
1296 | INSN_3(JMP, JLE, K), \ | |
1297 | INSN_3(JMP, JSGT, K), \ | |
1298 | INSN_3(JMP, JSLT, K), \ | |
1299 | INSN_3(JMP, JSGE, K), \ | |
1300 | INSN_3(JMP, JSLE, K), \ | |
1301 | INSN_3(JMP, JSET, K), \ | |
1302 | INSN_2(JMP, JA), \ | |
1303 | /* Store instructions. */ \ | |
1304 | /* Register based. */ \ | |
1305 | INSN_3(STX, MEM, B), \ | |
1306 | INSN_3(STX, MEM, H), \ | |
1307 | INSN_3(STX, MEM, W), \ | |
1308 | INSN_3(STX, MEM, DW), \ | |
1309 | INSN_3(STX, XADD, W), \ | |
1310 | INSN_3(STX, XADD, DW), \ | |
1311 | /* Immediate based. */ \ | |
1312 | INSN_3(ST, MEM, B), \ | |
1313 | INSN_3(ST, MEM, H), \ | |
1314 | INSN_3(ST, MEM, W), \ | |
1315 | INSN_3(ST, MEM, DW), \ | |
1316 | /* Load instructions. */ \ | |
1317 | /* Register based. */ \ | |
1318 | INSN_3(LDX, MEM, B), \ | |
1319 | INSN_3(LDX, MEM, H), \ | |
1320 | INSN_3(LDX, MEM, W), \ | |
1321 | INSN_3(LDX, MEM, DW), \ | |
1322 | /* Immediate based. */ \ | |
e0cea7ce | 1323 | INSN_3(LD, IMM, DW) |
5e581dad DB |
1324 | |
1325 | bool bpf_opcode_in_insntable(u8 code) | |
1326 | { | |
1327 | #define BPF_INSN_2_TBL(x, y) [BPF_##x | BPF_##y] = true | |
1328 | #define BPF_INSN_3_TBL(x, y, z) [BPF_##x | BPF_##y | BPF_##z] = true | |
1329 | static const bool public_insntable[256] = { | |
1330 | [0 ... 255] = false, | |
1331 | /* Now overwrite non-defaults ... */ | |
1332 | BPF_INSN_MAP(BPF_INSN_2_TBL, BPF_INSN_3_TBL), | |
e0cea7ce DB |
1333 | /* UAPI exposed, but rewritten opcodes. cBPF carry-over. */ |
1334 | [BPF_LD | BPF_ABS | BPF_B] = true, | |
1335 | [BPF_LD | BPF_ABS | BPF_H] = true, | |
1336 | [BPF_LD | BPF_ABS | BPF_W] = true, | |
1337 | [BPF_LD | BPF_IND | BPF_B] = true, | |
1338 | [BPF_LD | BPF_IND | BPF_H] = true, | |
1339 | [BPF_LD | BPF_IND | BPF_W] = true, | |
5e581dad DB |
1340 | }; |
1341 | #undef BPF_INSN_3_TBL | |
1342 | #undef BPF_INSN_2_TBL | |
1343 | return public_insntable[code]; | |
1344 | } | |
1345 | ||
290af866 | 1346 | #ifndef CONFIG_BPF_JIT_ALWAYS_ON |
6e07a634 | 1347 | u64 __weak bpf_probe_read_kernel(void *dst, u32 size, const void *unsafe_ptr) |
2a02759e AS |
1348 | { |
1349 | memset(dst, 0, size); | |
1350 | return -EFAULT; | |
1351 | } | |
6e07a634 | 1352 | |
f5bffecd | 1353 | /** |
7ae457c1 | 1354 | * __bpf_prog_run - run eBPF program on a given context |
de1da68d | 1355 | * @regs: is the array of MAX_BPF_EXT_REG eBPF pseudo-registers |
7ae457c1 | 1356 | * @insn: is the array of eBPF instructions |
de1da68d | 1357 | * @stack: is the eBPF storage stack |
f5bffecd | 1358 | * |
7ae457c1 | 1359 | * Decode and execute eBPF instructions. |
f5bffecd | 1360 | */ |
3193c083 | 1361 | static u64 __no_fgcse ___bpf_prog_run(u64 *regs, const struct bpf_insn *insn, u64 *stack) |
f5bffecd | 1362 | { |
5e581dad DB |
1363 | #define BPF_INSN_2_LBL(x, y) [BPF_##x | BPF_##y] = &&x##_##y |
1364 | #define BPF_INSN_3_LBL(x, y, z) [BPF_##x | BPF_##y | BPF_##z] = &&x##_##y##_##z | |
e55a7325 | 1365 | static const void * const jumptable[256] __annotate_jump_table = { |
f5bffecd AS |
1366 | [0 ... 255] = &&default_label, |
1367 | /* Now overwrite non-defaults ... */ | |
5e581dad DB |
1368 | BPF_INSN_MAP(BPF_INSN_2_LBL, BPF_INSN_3_LBL), |
1369 | /* Non-UAPI available opcodes. */ | |
1ea47e01 | 1370 | [BPF_JMP | BPF_CALL_ARGS] = &&JMP_CALL_ARGS, |
71189fa9 | 1371 | [BPF_JMP | BPF_TAIL_CALL] = &&JMP_TAIL_CALL, |
2a02759e AS |
1372 | [BPF_LDX | BPF_PROBE_MEM | BPF_B] = &&LDX_PROBE_MEM_B, |
1373 | [BPF_LDX | BPF_PROBE_MEM | BPF_H] = &&LDX_PROBE_MEM_H, | |
1374 | [BPF_LDX | BPF_PROBE_MEM | BPF_W] = &&LDX_PROBE_MEM_W, | |
1375 | [BPF_LDX | BPF_PROBE_MEM | BPF_DW] = &&LDX_PROBE_MEM_DW, | |
f5bffecd | 1376 | }; |
5e581dad DB |
1377 | #undef BPF_INSN_3_LBL |
1378 | #undef BPF_INSN_2_LBL | |
04fd61ab | 1379 | u32 tail_call_cnt = 0; |
f5bffecd AS |
1380 | |
1381 | #define CONT ({ insn++; goto select_insn; }) | |
1382 | #define CONT_JMP ({ insn++; goto select_insn; }) | |
1383 | ||
f5bffecd AS |
1384 | select_insn: |
1385 | goto *jumptable[insn->code]; | |
1386 | ||
1387 | /* ALU */ | |
1388 | #define ALU(OPCODE, OP) \ | |
1389 | ALU64_##OPCODE##_X: \ | |
1390 | DST = DST OP SRC; \ | |
1391 | CONT; \ | |
1392 | ALU_##OPCODE##_X: \ | |
1393 | DST = (u32) DST OP (u32) SRC; \ | |
1394 | CONT; \ | |
1395 | ALU64_##OPCODE##_K: \ | |
1396 | DST = DST OP IMM; \ | |
1397 | CONT; \ | |
1398 | ALU_##OPCODE##_K: \ | |
1399 | DST = (u32) DST OP (u32) IMM; \ | |
1400 | CONT; | |
1401 | ||
1402 | ALU(ADD, +) | |
1403 | ALU(SUB, -) | |
1404 | ALU(AND, &) | |
1405 | ALU(OR, |) | |
1406 | ALU(LSH, <<) | |
1407 | ALU(RSH, >>) | |
1408 | ALU(XOR, ^) | |
1409 | ALU(MUL, *) | |
1410 | #undef ALU | |
1411 | ALU_NEG: | |
1412 | DST = (u32) -DST; | |
1413 | CONT; | |
1414 | ALU64_NEG: | |
1415 | DST = -DST; | |
1416 | CONT; | |
1417 | ALU_MOV_X: | |
1418 | DST = (u32) SRC; | |
1419 | CONT; | |
1420 | ALU_MOV_K: | |
1421 | DST = (u32) IMM; | |
1422 | CONT; | |
1423 | ALU64_MOV_X: | |
1424 | DST = SRC; | |
1425 | CONT; | |
1426 | ALU64_MOV_K: | |
1427 | DST = IMM; | |
1428 | CONT; | |
02ab695b AS |
1429 | LD_IMM_DW: |
1430 | DST = (u64) (u32) insn[0].imm | ((u64) (u32) insn[1].imm) << 32; | |
1431 | insn++; | |
1432 | CONT; | |
2dc6b100 | 1433 | ALU_ARSH_X: |
75672dda | 1434 | DST = (u64) (u32) (((s32) DST) >> SRC); |
2dc6b100 JW |
1435 | CONT; |
1436 | ALU_ARSH_K: | |
75672dda | 1437 | DST = (u64) (u32) (((s32) DST) >> IMM); |
2dc6b100 | 1438 | CONT; |
f5bffecd AS |
1439 | ALU64_ARSH_X: |
1440 | (*(s64 *) &DST) >>= SRC; | |
1441 | CONT; | |
1442 | ALU64_ARSH_K: | |
1443 | (*(s64 *) &DST) >>= IMM; | |
1444 | CONT; | |
1445 | ALU64_MOD_X: | |
144cd91c DB |
1446 | div64_u64_rem(DST, SRC, &AX); |
1447 | DST = AX; | |
f5bffecd AS |
1448 | CONT; |
1449 | ALU_MOD_X: | |
144cd91c DB |
1450 | AX = (u32) DST; |
1451 | DST = do_div(AX, (u32) SRC); | |
f5bffecd AS |
1452 | CONT; |
1453 | ALU64_MOD_K: | |
144cd91c DB |
1454 | div64_u64_rem(DST, IMM, &AX); |
1455 | DST = AX; | |
f5bffecd AS |
1456 | CONT; |
1457 | ALU_MOD_K: | |
144cd91c DB |
1458 | AX = (u32) DST; |
1459 | DST = do_div(AX, (u32) IMM); | |
f5bffecd AS |
1460 | CONT; |
1461 | ALU64_DIV_X: | |
876a7ae6 | 1462 | DST = div64_u64(DST, SRC); |
f5bffecd AS |
1463 | CONT; |
1464 | ALU_DIV_X: | |
144cd91c DB |
1465 | AX = (u32) DST; |
1466 | do_div(AX, (u32) SRC); | |
1467 | DST = (u32) AX; | |
f5bffecd AS |
1468 | CONT; |
1469 | ALU64_DIV_K: | |
876a7ae6 | 1470 | DST = div64_u64(DST, IMM); |
f5bffecd AS |
1471 | CONT; |
1472 | ALU_DIV_K: | |
144cd91c DB |
1473 | AX = (u32) DST; |
1474 | do_div(AX, (u32) IMM); | |
1475 | DST = (u32) AX; | |
f5bffecd AS |
1476 | CONT; |
1477 | ALU_END_TO_BE: | |
1478 | switch (IMM) { | |
1479 | case 16: | |
1480 | DST = (__force u16) cpu_to_be16(DST); | |
1481 | break; | |
1482 | case 32: | |
1483 | DST = (__force u32) cpu_to_be32(DST); | |
1484 | break; | |
1485 | case 64: | |
1486 | DST = (__force u64) cpu_to_be64(DST); | |
1487 | break; | |
1488 | } | |
1489 | CONT; | |
1490 | ALU_END_TO_LE: | |
1491 | switch (IMM) { | |
1492 | case 16: | |
1493 | DST = (__force u16) cpu_to_le16(DST); | |
1494 | break; | |
1495 | case 32: | |
1496 | DST = (__force u32) cpu_to_le32(DST); | |
1497 | break; | |
1498 | case 64: | |
1499 | DST = (__force u64) cpu_to_le64(DST); | |
1500 | break; | |
1501 | } | |
1502 | CONT; | |
1503 | ||
1504 | /* CALL */ | |
1505 | JMP_CALL: | |
1506 | /* Function call scratches BPF_R1-BPF_R5 registers, | |
1507 | * preserves BPF_R6-BPF_R9, and stores return value | |
1508 | * into BPF_R0. | |
1509 | */ | |
1510 | BPF_R0 = (__bpf_call_base + insn->imm)(BPF_R1, BPF_R2, BPF_R3, | |
1511 | BPF_R4, BPF_R5); | |
1512 | CONT; | |
1513 | ||
1ea47e01 AS |
1514 | JMP_CALL_ARGS: |
1515 | BPF_R0 = (__bpf_call_base_args + insn->imm)(BPF_R1, BPF_R2, | |
1516 | BPF_R3, BPF_R4, | |
1517 | BPF_R5, | |
1518 | insn + insn->off + 1); | |
1519 | CONT; | |
1520 | ||
04fd61ab AS |
1521 | JMP_TAIL_CALL: { |
1522 | struct bpf_map *map = (struct bpf_map *) (unsigned long) BPF_R2; | |
1523 | struct bpf_array *array = container_of(map, struct bpf_array, map); | |
1524 | struct bpf_prog *prog; | |
90caccdd | 1525 | u32 index = BPF_R3; |
04fd61ab AS |
1526 | |
1527 | if (unlikely(index >= array->map.max_entries)) | |
1528 | goto out; | |
04fd61ab AS |
1529 | if (unlikely(tail_call_cnt > MAX_TAIL_CALL_CNT)) |
1530 | goto out; | |
1531 | ||
1532 | tail_call_cnt++; | |
1533 | ||
2a36f0b9 | 1534 | prog = READ_ONCE(array->ptrs[index]); |
1ca1cc98 | 1535 | if (!prog) |
04fd61ab AS |
1536 | goto out; |
1537 | ||
c4675f93 DB |
1538 | /* ARG1 at this point is guaranteed to point to CTX from |
1539 | * the verifier side due to the fact that the tail call is | |
1540 | * handeled like a helper, that is, bpf_tail_call_proto, | |
1541 | * where arg1_type is ARG_PTR_TO_CTX. | |
1542 | */ | |
04fd61ab AS |
1543 | insn = prog->insnsi; |
1544 | goto select_insn; | |
1545 | out: | |
1546 | CONT; | |
1547 | } | |
f5bffecd AS |
1548 | JMP_JA: |
1549 | insn += insn->off; | |
1550 | CONT; | |
f5bffecd AS |
1551 | JMP_EXIT: |
1552 | return BPF_R0; | |
503a8865 JW |
1553 | /* JMP */ |
1554 | #define COND_JMP(SIGN, OPCODE, CMP_OP) \ | |
1555 | JMP_##OPCODE##_X: \ | |
1556 | if ((SIGN##64) DST CMP_OP (SIGN##64) SRC) { \ | |
1557 | insn += insn->off; \ | |
1558 | CONT_JMP; \ | |
1559 | } \ | |
1560 | CONT; \ | |
1561 | JMP32_##OPCODE##_X: \ | |
1562 | if ((SIGN##32) DST CMP_OP (SIGN##32) SRC) { \ | |
1563 | insn += insn->off; \ | |
1564 | CONT_JMP; \ | |
1565 | } \ | |
1566 | CONT; \ | |
1567 | JMP_##OPCODE##_K: \ | |
1568 | if ((SIGN##64) DST CMP_OP (SIGN##64) IMM) { \ | |
1569 | insn += insn->off; \ | |
1570 | CONT_JMP; \ | |
1571 | } \ | |
1572 | CONT; \ | |
1573 | JMP32_##OPCODE##_K: \ | |
1574 | if ((SIGN##32) DST CMP_OP (SIGN##32) IMM) { \ | |
1575 | insn += insn->off; \ | |
1576 | CONT_JMP; \ | |
1577 | } \ | |
1578 | CONT; | |
1579 | COND_JMP(u, JEQ, ==) | |
1580 | COND_JMP(u, JNE, !=) | |
1581 | COND_JMP(u, JGT, >) | |
1582 | COND_JMP(u, JLT, <) | |
1583 | COND_JMP(u, JGE, >=) | |
1584 | COND_JMP(u, JLE, <=) | |
1585 | COND_JMP(u, JSET, &) | |
1586 | COND_JMP(s, JSGT, >) | |
1587 | COND_JMP(s, JSLT, <) | |
1588 | COND_JMP(s, JSGE, >=) | |
1589 | COND_JMP(s, JSLE, <=) | |
1590 | #undef COND_JMP | |
f5bffecd AS |
1591 | /* STX and ST and LDX*/ |
1592 | #define LDST(SIZEOP, SIZE) \ | |
1593 | STX_MEM_##SIZEOP: \ | |
1594 | *(SIZE *)(unsigned long) (DST + insn->off) = SRC; \ | |
1595 | CONT; \ | |
1596 | ST_MEM_##SIZEOP: \ | |
1597 | *(SIZE *)(unsigned long) (DST + insn->off) = IMM; \ | |
1598 | CONT; \ | |
1599 | LDX_MEM_##SIZEOP: \ | |
1600 | DST = *(SIZE *)(unsigned long) (SRC + insn->off); \ | |
1601 | CONT; | |
1602 | ||
1603 | LDST(B, u8) | |
1604 | LDST(H, u16) | |
1605 | LDST(W, u32) | |
1606 | LDST(DW, u64) | |
1607 | #undef LDST | |
6e07a634 DB |
1608 | #define LDX_PROBE(SIZEOP, SIZE) \ |
1609 | LDX_PROBE_MEM_##SIZEOP: \ | |
85d31dd0 | 1610 | bpf_probe_read_kernel(&DST, SIZE, (const void *)(long) (SRC + insn->off)); \ |
2a02759e AS |
1611 | CONT; |
1612 | LDX_PROBE(B, 1) | |
1613 | LDX_PROBE(H, 2) | |
1614 | LDX_PROBE(W, 4) | |
1615 | LDX_PROBE(DW, 8) | |
1616 | #undef LDX_PROBE | |
1617 | ||
f5bffecd AS |
1618 | STX_XADD_W: /* lock xadd *(u32 *)(dst_reg + off16) += src_reg */ |
1619 | atomic_add((u32) SRC, (atomic_t *)(unsigned long) | |
1620 | (DST + insn->off)); | |
1621 | CONT; | |
1622 | STX_XADD_DW: /* lock xadd *(u64 *)(dst_reg + off16) += src_reg */ | |
1623 | atomic64_add((u64) SRC, (atomic64_t *)(unsigned long) | |
1624 | (DST + insn->off)); | |
1625 | CONT; | |
f5bffecd AS |
1626 | |
1627 | default_label: | |
5e581dad DB |
1628 | /* If we ever reach this, we have a bug somewhere. Die hard here |
1629 | * instead of just returning 0; we could be somewhere in a subprog, | |
1630 | * so execution could continue otherwise which we do /not/ want. | |
1631 | * | |
1632 | * Note, verifier whitelists all opcodes in bpf_opcode_in_insntable(). | |
1633 | */ | |
1634 | pr_warn("BPF interpreter: unknown opcode %02x\n", insn->code); | |
1635 | BUG_ON(1); | |
f5bffecd AS |
1636 | return 0; |
1637 | } | |
f696b8f4 | 1638 | |
b870aa90 AS |
1639 | #define PROG_NAME(stack_size) __bpf_prog_run##stack_size |
1640 | #define DEFINE_BPF_PROG_RUN(stack_size) \ | |
1641 | static unsigned int PROG_NAME(stack_size)(const void *ctx, const struct bpf_insn *insn) \ | |
1642 | { \ | |
1643 | u64 stack[stack_size / sizeof(u64)]; \ | |
144cd91c | 1644 | u64 regs[MAX_BPF_EXT_REG]; \ |
b870aa90 AS |
1645 | \ |
1646 | FP = (u64) (unsigned long) &stack[ARRAY_SIZE(stack)]; \ | |
1647 | ARG1 = (u64) (unsigned long) ctx; \ | |
1648 | return ___bpf_prog_run(regs, insn, stack); \ | |
f696b8f4 | 1649 | } |
f5bffecd | 1650 | |
1ea47e01 AS |
1651 | #define PROG_NAME_ARGS(stack_size) __bpf_prog_run_args##stack_size |
1652 | #define DEFINE_BPF_PROG_RUN_ARGS(stack_size) \ | |
1653 | static u64 PROG_NAME_ARGS(stack_size)(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5, \ | |
1654 | const struct bpf_insn *insn) \ | |
1655 | { \ | |
1656 | u64 stack[stack_size / sizeof(u64)]; \ | |
144cd91c | 1657 | u64 regs[MAX_BPF_EXT_REG]; \ |
1ea47e01 AS |
1658 | \ |
1659 | FP = (u64) (unsigned long) &stack[ARRAY_SIZE(stack)]; \ | |
1660 | BPF_R1 = r1; \ | |
1661 | BPF_R2 = r2; \ | |
1662 | BPF_R3 = r3; \ | |
1663 | BPF_R4 = r4; \ | |
1664 | BPF_R5 = r5; \ | |
1665 | return ___bpf_prog_run(regs, insn, stack); \ | |
1666 | } | |
1667 | ||
b870aa90 AS |
1668 | #define EVAL1(FN, X) FN(X) |
1669 | #define EVAL2(FN, X, Y...) FN(X) EVAL1(FN, Y) | |
1670 | #define EVAL3(FN, X, Y...) FN(X) EVAL2(FN, Y) | |
1671 | #define EVAL4(FN, X, Y...) FN(X) EVAL3(FN, Y) | |
1672 | #define EVAL5(FN, X, Y...) FN(X) EVAL4(FN, Y) | |
1673 | #define EVAL6(FN, X, Y...) FN(X) EVAL5(FN, Y) | |
1674 | ||
1675 | EVAL6(DEFINE_BPF_PROG_RUN, 32, 64, 96, 128, 160, 192); | |
1676 | EVAL6(DEFINE_BPF_PROG_RUN, 224, 256, 288, 320, 352, 384); | |
1677 | EVAL4(DEFINE_BPF_PROG_RUN, 416, 448, 480, 512); | |
1678 | ||
1ea47e01 AS |
1679 | EVAL6(DEFINE_BPF_PROG_RUN_ARGS, 32, 64, 96, 128, 160, 192); |
1680 | EVAL6(DEFINE_BPF_PROG_RUN_ARGS, 224, 256, 288, 320, 352, 384); | |
1681 | EVAL4(DEFINE_BPF_PROG_RUN_ARGS, 416, 448, 480, 512); | |
1682 | ||
b870aa90 AS |
1683 | #define PROG_NAME_LIST(stack_size) PROG_NAME(stack_size), |
1684 | ||
1685 | static unsigned int (*interpreters[])(const void *ctx, | |
1686 | const struct bpf_insn *insn) = { | |
1687 | EVAL6(PROG_NAME_LIST, 32, 64, 96, 128, 160, 192) | |
1688 | EVAL6(PROG_NAME_LIST, 224, 256, 288, 320, 352, 384) | |
1689 | EVAL4(PROG_NAME_LIST, 416, 448, 480, 512) | |
1690 | }; | |
1ea47e01 AS |
1691 | #undef PROG_NAME_LIST |
1692 | #define PROG_NAME_LIST(stack_size) PROG_NAME_ARGS(stack_size), | |
1693 | static u64 (*interpreters_args[])(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5, | |
1694 | const struct bpf_insn *insn) = { | |
1695 | EVAL6(PROG_NAME_LIST, 32, 64, 96, 128, 160, 192) | |
1696 | EVAL6(PROG_NAME_LIST, 224, 256, 288, 320, 352, 384) | |
1697 | EVAL4(PROG_NAME_LIST, 416, 448, 480, 512) | |
1698 | }; | |
1699 | #undef PROG_NAME_LIST | |
1700 | ||
1701 | void bpf_patch_call_args(struct bpf_insn *insn, u32 stack_depth) | |
1702 | { | |
1703 | stack_depth = max_t(u32, stack_depth, 1); | |
1704 | insn->off = (s16) insn->imm; | |
1705 | insn->imm = interpreters_args[(round_up(stack_depth, 32) / 32) - 1] - | |
1706 | __bpf_call_base_args; | |
1707 | insn->code = BPF_JMP | BPF_CALL_ARGS; | |
1708 | } | |
b870aa90 | 1709 | |
290af866 | 1710 | #else |
fa9dd599 DB |
1711 | static unsigned int __bpf_prog_ret0_warn(const void *ctx, |
1712 | const struct bpf_insn *insn) | |
290af866 | 1713 | { |
fa9dd599 DB |
1714 | /* If this handler ever gets executed, then BPF_JIT_ALWAYS_ON |
1715 | * is not working properly, so warn about it! | |
1716 | */ | |
1717 | WARN_ON_ONCE(1); | |
290af866 AS |
1718 | return 0; |
1719 | } | |
1720 | #endif | |
1721 | ||
3324b584 DB |
1722 | bool bpf_prog_array_compatible(struct bpf_array *array, |
1723 | const struct bpf_prog *fp) | |
04fd61ab | 1724 | { |
9802d865 JB |
1725 | if (fp->kprobe_override) |
1726 | return false; | |
1727 | ||
2beee5f5 | 1728 | if (!array->aux->type) { |
3324b584 DB |
1729 | /* There's no owner yet where we could check for |
1730 | * compatibility. | |
1731 | */ | |
2beee5f5 DB |
1732 | array->aux->type = fp->type; |
1733 | array->aux->jited = fp->jited; | |
3324b584 | 1734 | return true; |
04fd61ab | 1735 | } |
3324b584 | 1736 | |
2beee5f5 DB |
1737 | return array->aux->type == fp->type && |
1738 | array->aux->jited == fp->jited; | |
04fd61ab AS |
1739 | } |
1740 | ||
3324b584 | 1741 | static int bpf_check_tail_call(const struct bpf_prog *fp) |
04fd61ab AS |
1742 | { |
1743 | struct bpf_prog_aux *aux = fp->aux; | |
1744 | int i; | |
1745 | ||
1746 | for (i = 0; i < aux->used_map_cnt; i++) { | |
3324b584 | 1747 | struct bpf_map *map = aux->used_maps[i]; |
04fd61ab | 1748 | struct bpf_array *array; |
04fd61ab | 1749 | |
04fd61ab AS |
1750 | if (map->map_type != BPF_MAP_TYPE_PROG_ARRAY) |
1751 | continue; | |
3324b584 | 1752 | |
04fd61ab AS |
1753 | array = container_of(map, struct bpf_array, map); |
1754 | if (!bpf_prog_array_compatible(array, fp)) | |
1755 | return -EINVAL; | |
1756 | } | |
1757 | ||
1758 | return 0; | |
1759 | } | |
1760 | ||
9facc336 DB |
1761 | static void bpf_prog_select_func(struct bpf_prog *fp) |
1762 | { | |
1763 | #ifndef CONFIG_BPF_JIT_ALWAYS_ON | |
1764 | u32 stack_depth = max_t(u32, fp->aux->stack_depth, 1); | |
1765 | ||
1766 | fp->bpf_func = interpreters[(round_up(stack_depth, 32) / 32) - 1]; | |
1767 | #else | |
1768 | fp->bpf_func = __bpf_prog_ret0_warn; | |
1769 | #endif | |
1770 | } | |
1771 | ||
f5bffecd | 1772 | /** |
3324b584 | 1773 | * bpf_prog_select_runtime - select exec runtime for BPF program |
7ae457c1 | 1774 | * @fp: bpf_prog populated with internal BPF program |
d1c55ab5 | 1775 | * @err: pointer to error variable |
f5bffecd | 1776 | * |
3324b584 DB |
1777 | * Try to JIT eBPF program, if JIT is not available, use interpreter. |
1778 | * The BPF program will be executed via BPF_PROG_RUN() macro. | |
f5bffecd | 1779 | */ |
d1c55ab5 | 1780 | struct bpf_prog *bpf_prog_select_runtime(struct bpf_prog *fp, int *err) |
f5bffecd | 1781 | { |
9facc336 DB |
1782 | /* In case of BPF to BPF calls, verifier did all the prep |
1783 | * work with regards to JITing, etc. | |
1784 | */ | |
1785 | if (fp->bpf_func) | |
1786 | goto finalize; | |
8007e40a | 1787 | |
9facc336 | 1788 | bpf_prog_select_func(fp); |
f5bffecd | 1789 | |
d1c55ab5 DB |
1790 | /* eBPF JITs can rewrite the program in case constant |
1791 | * blinding is active. However, in case of error during | |
1792 | * blinding, bpf_int_jit_compile() must always return a | |
1793 | * valid program, which in this case would simply not | |
1794 | * be JITed, but falls back to the interpreter. | |
1795 | */ | |
ab3f0063 | 1796 | if (!bpf_prog_is_dev_bound(fp->aux)) { |
c454a46b MKL |
1797 | *err = bpf_prog_alloc_jited_linfo(fp); |
1798 | if (*err) | |
1799 | return fp; | |
1800 | ||
ab3f0063 | 1801 | fp = bpf_int_jit_compile(fp); |
290af866 | 1802 | if (!fp->jited) { |
c454a46b MKL |
1803 | bpf_prog_free_jited_linfo(fp); |
1804 | #ifdef CONFIG_BPF_JIT_ALWAYS_ON | |
290af866 AS |
1805 | *err = -ENOTSUPP; |
1806 | return fp; | |
290af866 | 1807 | #endif |
c454a46b MKL |
1808 | } else { |
1809 | bpf_prog_free_unused_jited_linfo(fp); | |
1810 | } | |
ab3f0063 JK |
1811 | } else { |
1812 | *err = bpf_prog_offload_compile(fp); | |
1813 | if (*err) | |
1814 | return fp; | |
1815 | } | |
9facc336 DB |
1816 | |
1817 | finalize: | |
60a3b225 | 1818 | bpf_prog_lock_ro(fp); |
04fd61ab | 1819 | |
3324b584 DB |
1820 | /* The tail call compatibility check can only be done at |
1821 | * this late stage as we need to determine, if we deal | |
1822 | * with JITed or non JITed program concatenations and not | |
1823 | * all eBPF JITs might immediately support all features. | |
1824 | */ | |
d1c55ab5 | 1825 | *err = bpf_check_tail_call(fp); |
85782e03 | 1826 | |
d1c55ab5 | 1827 | return fp; |
f5bffecd | 1828 | } |
7ae457c1 | 1829 | EXPORT_SYMBOL_GPL(bpf_prog_select_runtime); |
f5bffecd | 1830 | |
e87c6bc3 YS |
1831 | static unsigned int __bpf_prog_ret1(const void *ctx, |
1832 | const struct bpf_insn *insn) | |
1833 | { | |
1834 | return 1; | |
1835 | } | |
1836 | ||
1837 | static struct bpf_prog_dummy { | |
1838 | struct bpf_prog prog; | |
1839 | } dummy_bpf_prog = { | |
1840 | .prog = { | |
1841 | .bpf_func = __bpf_prog_ret1, | |
1842 | }, | |
1843 | }; | |
1844 | ||
324bda9e AS |
1845 | /* to avoid allocating empty bpf_prog_array for cgroups that |
1846 | * don't have bpf program attached use one global 'empty_prog_array' | |
1847 | * It will not be modified the caller of bpf_prog_array_alloc() | |
1848 | * (since caller requested prog_cnt == 0) | |
1849 | * that pointer should be 'freed' by bpf_prog_array_free() | |
1850 | */ | |
1851 | static struct { | |
1852 | struct bpf_prog_array hdr; | |
1853 | struct bpf_prog *null_prog; | |
1854 | } empty_prog_array = { | |
1855 | .null_prog = NULL, | |
1856 | }; | |
1857 | ||
d29ab6e1 | 1858 | struct bpf_prog_array *bpf_prog_array_alloc(u32 prog_cnt, gfp_t flags) |
324bda9e AS |
1859 | { |
1860 | if (prog_cnt) | |
1861 | return kzalloc(sizeof(struct bpf_prog_array) + | |
394e40a2 RG |
1862 | sizeof(struct bpf_prog_array_item) * |
1863 | (prog_cnt + 1), | |
324bda9e AS |
1864 | flags); |
1865 | ||
1866 | return &empty_prog_array.hdr; | |
1867 | } | |
1868 | ||
54e9c9d4 | 1869 | void bpf_prog_array_free(struct bpf_prog_array *progs) |
324bda9e | 1870 | { |
54e9c9d4 | 1871 | if (!progs || progs == &empty_prog_array.hdr) |
324bda9e AS |
1872 | return; |
1873 | kfree_rcu(progs, rcu); | |
1874 | } | |
1875 | ||
54e9c9d4 | 1876 | int bpf_prog_array_length(struct bpf_prog_array *array) |
468e2f64 | 1877 | { |
394e40a2 | 1878 | struct bpf_prog_array_item *item; |
468e2f64 AS |
1879 | u32 cnt = 0; |
1880 | ||
54e9c9d4 | 1881 | for (item = array->items; item->prog; item++) |
394e40a2 | 1882 | if (item->prog != &dummy_bpf_prog.prog) |
c8c088ba | 1883 | cnt++; |
468e2f64 AS |
1884 | return cnt; |
1885 | } | |
1886 | ||
0d01da6a SF |
1887 | bool bpf_prog_array_is_empty(struct bpf_prog_array *array) |
1888 | { | |
1889 | struct bpf_prog_array_item *item; | |
1890 | ||
1891 | for (item = array->items; item->prog; item++) | |
1892 | if (item->prog != &dummy_bpf_prog.prog) | |
1893 | return false; | |
1894 | return true; | |
1895 | } | |
394e40a2 | 1896 | |
54e9c9d4 | 1897 | static bool bpf_prog_array_copy_core(struct bpf_prog_array *array, |
3a38bb98 YS |
1898 | u32 *prog_ids, |
1899 | u32 request_cnt) | |
1900 | { | |
394e40a2 | 1901 | struct bpf_prog_array_item *item; |
3a38bb98 YS |
1902 | int i = 0; |
1903 | ||
54e9c9d4 | 1904 | for (item = array->items; item->prog; item++) { |
394e40a2 | 1905 | if (item->prog == &dummy_bpf_prog.prog) |
3a38bb98 | 1906 | continue; |
394e40a2 | 1907 | prog_ids[i] = item->prog->aux->id; |
3a38bb98 | 1908 | if (++i == request_cnt) { |
394e40a2 | 1909 | item++; |
3a38bb98 YS |
1910 | break; |
1911 | } | |
1912 | } | |
1913 | ||
394e40a2 | 1914 | return !!(item->prog); |
3a38bb98 YS |
1915 | } |
1916 | ||
54e9c9d4 | 1917 | int bpf_prog_array_copy_to_user(struct bpf_prog_array *array, |
468e2f64 AS |
1918 | __u32 __user *prog_ids, u32 cnt) |
1919 | { | |
0911287c | 1920 | unsigned long err = 0; |
0911287c | 1921 | bool nospc; |
3a38bb98 | 1922 | u32 *ids; |
0911287c AS |
1923 | |
1924 | /* users of this function are doing: | |
1925 | * cnt = bpf_prog_array_length(); | |
1926 | * if (cnt > 0) | |
1927 | * bpf_prog_array_copy_to_user(..., cnt); | |
54e9c9d4 | 1928 | * so below kcalloc doesn't need extra cnt > 0 check. |
0911287c | 1929 | */ |
9c481b90 | 1930 | ids = kcalloc(cnt, sizeof(u32), GFP_USER | __GFP_NOWARN); |
0911287c AS |
1931 | if (!ids) |
1932 | return -ENOMEM; | |
394e40a2 | 1933 | nospc = bpf_prog_array_copy_core(array, ids, cnt); |
0911287c AS |
1934 | err = copy_to_user(prog_ids, ids, cnt * sizeof(u32)); |
1935 | kfree(ids); | |
1936 | if (err) | |
1937 | return -EFAULT; | |
1938 | if (nospc) | |
468e2f64 AS |
1939 | return -ENOSPC; |
1940 | return 0; | |
1941 | } | |
1942 | ||
54e9c9d4 | 1943 | void bpf_prog_array_delete_safe(struct bpf_prog_array *array, |
e87c6bc3 YS |
1944 | struct bpf_prog *old_prog) |
1945 | { | |
54e9c9d4 | 1946 | struct bpf_prog_array_item *item; |
e87c6bc3 | 1947 | |
54e9c9d4 | 1948 | for (item = array->items; item->prog; item++) |
394e40a2 RG |
1949 | if (item->prog == old_prog) { |
1950 | WRITE_ONCE(item->prog, &dummy_bpf_prog.prog); | |
e87c6bc3 YS |
1951 | break; |
1952 | } | |
1953 | } | |
1954 | ||
54e9c9d4 | 1955 | int bpf_prog_array_copy(struct bpf_prog_array *old_array, |
e87c6bc3 YS |
1956 | struct bpf_prog *exclude_prog, |
1957 | struct bpf_prog *include_prog, | |
1958 | struct bpf_prog_array **new_array) | |
1959 | { | |
1960 | int new_prog_cnt, carry_prog_cnt = 0; | |
394e40a2 | 1961 | struct bpf_prog_array_item *existing; |
e87c6bc3 | 1962 | struct bpf_prog_array *array; |
170a7e3e | 1963 | bool found_exclude = false; |
e87c6bc3 YS |
1964 | int new_prog_idx = 0; |
1965 | ||
1966 | /* Figure out how many existing progs we need to carry over to | |
1967 | * the new array. | |
1968 | */ | |
1969 | if (old_array) { | |
394e40a2 RG |
1970 | existing = old_array->items; |
1971 | for (; existing->prog; existing++) { | |
1972 | if (existing->prog == exclude_prog) { | |
170a7e3e SY |
1973 | found_exclude = true; |
1974 | continue; | |
1975 | } | |
394e40a2 | 1976 | if (existing->prog != &dummy_bpf_prog.prog) |
e87c6bc3 | 1977 | carry_prog_cnt++; |
394e40a2 | 1978 | if (existing->prog == include_prog) |
e87c6bc3 YS |
1979 | return -EEXIST; |
1980 | } | |
1981 | } | |
1982 | ||
170a7e3e SY |
1983 | if (exclude_prog && !found_exclude) |
1984 | return -ENOENT; | |
1985 | ||
e87c6bc3 YS |
1986 | /* How many progs (not NULL) will be in the new array? */ |
1987 | new_prog_cnt = carry_prog_cnt; | |
1988 | if (include_prog) | |
1989 | new_prog_cnt += 1; | |
1990 | ||
1991 | /* Do we have any prog (not NULL) in the new array? */ | |
1992 | if (!new_prog_cnt) { | |
1993 | *new_array = NULL; | |
1994 | return 0; | |
1995 | } | |
1996 | ||
1997 | /* +1 as the end of prog_array is marked with NULL */ | |
1998 | array = bpf_prog_array_alloc(new_prog_cnt + 1, GFP_KERNEL); | |
1999 | if (!array) | |
2000 | return -ENOMEM; | |
2001 | ||
2002 | /* Fill in the new prog array */ | |
2003 | if (carry_prog_cnt) { | |
394e40a2 RG |
2004 | existing = old_array->items; |
2005 | for (; existing->prog; existing++) | |
2006 | if (existing->prog != exclude_prog && | |
2007 | existing->prog != &dummy_bpf_prog.prog) { | |
2008 | array->items[new_prog_idx++].prog = | |
2009 | existing->prog; | |
2010 | } | |
e87c6bc3 YS |
2011 | } |
2012 | if (include_prog) | |
394e40a2 RG |
2013 | array->items[new_prog_idx++].prog = include_prog; |
2014 | array->items[new_prog_idx].prog = NULL; | |
e87c6bc3 YS |
2015 | *new_array = array; |
2016 | return 0; | |
2017 | } | |
2018 | ||
54e9c9d4 | 2019 | int bpf_prog_array_copy_info(struct bpf_prog_array *array, |
3a38bb98 YS |
2020 | u32 *prog_ids, u32 request_cnt, |
2021 | u32 *prog_cnt) | |
f371b304 YS |
2022 | { |
2023 | u32 cnt = 0; | |
2024 | ||
2025 | if (array) | |
2026 | cnt = bpf_prog_array_length(array); | |
2027 | ||
3a38bb98 | 2028 | *prog_cnt = cnt; |
f371b304 YS |
2029 | |
2030 | /* return early if user requested only program count or nothing to copy */ | |
2031 | if (!request_cnt || !cnt) | |
2032 | return 0; | |
2033 | ||
3a38bb98 | 2034 | /* this function is called under trace/bpf_trace.c: bpf_event_mutex */ |
394e40a2 | 2035 | return bpf_prog_array_copy_core(array, prog_ids, request_cnt) ? -ENOSPC |
3a38bb98 | 2036 | : 0; |
f371b304 YS |
2037 | } |
2038 | ||
6332be04 DB |
2039 | static void bpf_free_cgroup_storage(struct bpf_prog_aux *aux) |
2040 | { | |
2041 | enum bpf_cgroup_storage_type stype; | |
2042 | ||
2043 | for_each_cgroup_storage_type(stype) { | |
2044 | if (!aux->cgroup_storage[stype]) | |
2045 | continue; | |
2046 | bpf_cgroup_storage_release(aux->prog, | |
2047 | aux->cgroup_storage[stype]); | |
2048 | } | |
2049 | } | |
2050 | ||
2051 | static void bpf_free_used_maps(struct bpf_prog_aux *aux) | |
2052 | { | |
da765a2f | 2053 | struct bpf_map *map; |
6332be04 DB |
2054 | int i; |
2055 | ||
2056 | bpf_free_cgroup_storage(aux); | |
da765a2f DB |
2057 | for (i = 0; i < aux->used_map_cnt; i++) { |
2058 | map = aux->used_maps[i]; | |
2059 | if (map->ops->map_poke_untrack) | |
2060 | map->ops->map_poke_untrack(map, aux); | |
2061 | bpf_map_put(map); | |
2062 | } | |
6332be04 DB |
2063 | kfree(aux->used_maps); |
2064 | } | |
2065 | ||
60a3b225 DB |
2066 | static void bpf_prog_free_deferred(struct work_struct *work) |
2067 | { | |
09756af4 | 2068 | struct bpf_prog_aux *aux; |
1c2a088a | 2069 | int i; |
60a3b225 | 2070 | |
09756af4 | 2071 | aux = container_of(work, struct bpf_prog_aux, work); |
6332be04 | 2072 | bpf_free_used_maps(aux); |
ab3f0063 JK |
2073 | if (bpf_prog_is_dev_bound(aux)) |
2074 | bpf_prog_offload_destroy(aux->prog); | |
c195651e YS |
2075 | #ifdef CONFIG_PERF_EVENTS |
2076 | if (aux->prog->has_callchain_buf) | |
2077 | put_callchain_buffers(); | |
2078 | #endif | |
fec56f58 | 2079 | bpf_trampoline_put(aux->trampoline); |
1c2a088a AS |
2080 | for (i = 0; i < aux->func_cnt; i++) |
2081 | bpf_jit_free(aux->func[i]); | |
2082 | if (aux->func_cnt) { | |
2083 | kfree(aux->func); | |
2084 | bpf_prog_unlock_free(aux->prog); | |
2085 | } else { | |
2086 | bpf_jit_free(aux->prog); | |
2087 | } | |
60a3b225 DB |
2088 | } |
2089 | ||
2090 | /* Free internal BPF program */ | |
7ae457c1 | 2091 | void bpf_prog_free(struct bpf_prog *fp) |
f5bffecd | 2092 | { |
09756af4 | 2093 | struct bpf_prog_aux *aux = fp->aux; |
60a3b225 | 2094 | |
5b92a28a AS |
2095 | if (aux->linked_prog) |
2096 | bpf_prog_put(aux->linked_prog); | |
09756af4 | 2097 | INIT_WORK(&aux->work, bpf_prog_free_deferred); |
09756af4 | 2098 | schedule_work(&aux->work); |
f5bffecd | 2099 | } |
7ae457c1 | 2100 | EXPORT_SYMBOL_GPL(bpf_prog_free); |
f89b7755 | 2101 | |
3ad00405 DB |
2102 | /* RNG for unpriviledged user space with separated state from prandom_u32(). */ |
2103 | static DEFINE_PER_CPU(struct rnd_state, bpf_user_rnd_state); | |
2104 | ||
2105 | void bpf_user_rnd_init_once(void) | |
2106 | { | |
2107 | prandom_init_once(&bpf_user_rnd_state); | |
2108 | } | |
2109 | ||
f3694e00 | 2110 | BPF_CALL_0(bpf_user_rnd_u32) |
3ad00405 DB |
2111 | { |
2112 | /* Should someone ever have the rather unwise idea to use some | |
2113 | * of the registers passed into this function, then note that | |
2114 | * this function is called from native eBPF and classic-to-eBPF | |
2115 | * transformations. Register assignments from both sides are | |
2116 | * different, f.e. classic always sets fn(ctx, A, X) here. | |
2117 | */ | |
2118 | struct rnd_state *state; | |
2119 | u32 res; | |
2120 | ||
2121 | state = &get_cpu_var(bpf_user_rnd_state); | |
2122 | res = prandom_u32_state(state); | |
b761fe22 | 2123 | put_cpu_var(bpf_user_rnd_state); |
3ad00405 DB |
2124 | |
2125 | return res; | |
2126 | } | |
2127 | ||
3ba67dab DB |
2128 | /* Weak definitions of helper functions in case we don't have bpf syscall. */ |
2129 | const struct bpf_func_proto bpf_map_lookup_elem_proto __weak; | |
2130 | const struct bpf_func_proto bpf_map_update_elem_proto __weak; | |
2131 | const struct bpf_func_proto bpf_map_delete_elem_proto __weak; | |
f1a2e44a MV |
2132 | const struct bpf_func_proto bpf_map_push_elem_proto __weak; |
2133 | const struct bpf_func_proto bpf_map_pop_elem_proto __weak; | |
2134 | const struct bpf_func_proto bpf_map_peek_elem_proto __weak; | |
d83525ca AS |
2135 | const struct bpf_func_proto bpf_spin_lock_proto __weak; |
2136 | const struct bpf_func_proto bpf_spin_unlock_proto __weak; | |
3ba67dab | 2137 | |
03e69b50 | 2138 | const struct bpf_func_proto bpf_get_prandom_u32_proto __weak; |
c04167ce | 2139 | const struct bpf_func_proto bpf_get_smp_processor_id_proto __weak; |
2d0e30c3 | 2140 | const struct bpf_func_proto bpf_get_numa_node_id_proto __weak; |
17ca8cbf | 2141 | const struct bpf_func_proto bpf_ktime_get_ns_proto __weak; |
bd570ff9 | 2142 | |
ffeedafb AS |
2143 | const struct bpf_func_proto bpf_get_current_pid_tgid_proto __weak; |
2144 | const struct bpf_func_proto bpf_get_current_uid_gid_proto __weak; | |
2145 | const struct bpf_func_proto bpf_get_current_comm_proto __weak; | |
bf6fa2c8 | 2146 | const struct bpf_func_proto bpf_get_current_cgroup_id_proto __weak; |
cd339431 | 2147 | const struct bpf_func_proto bpf_get_local_storage_proto __weak; |
bd570ff9 | 2148 | |
0756ea3e AS |
2149 | const struct bpf_func_proto * __weak bpf_get_trace_printk_proto(void) |
2150 | { | |
2151 | return NULL; | |
2152 | } | |
03e69b50 | 2153 | |
555c8a86 DB |
2154 | u64 __weak |
2155 | bpf_event_output(struct bpf_map *map, u64 flags, void *meta, u64 meta_size, | |
2156 | void *ctx, u64 ctx_size, bpf_ctx_copy_t ctx_copy) | |
bd570ff9 | 2157 | { |
555c8a86 | 2158 | return -ENOTSUPP; |
bd570ff9 | 2159 | } |
6cb5fb38 | 2160 | EXPORT_SYMBOL_GPL(bpf_event_output); |
bd570ff9 | 2161 | |
3324b584 DB |
2162 | /* Always built-in helper functions. */ |
2163 | const struct bpf_func_proto bpf_tail_call_proto = { | |
2164 | .func = NULL, | |
2165 | .gpl_only = false, | |
2166 | .ret_type = RET_VOID, | |
2167 | .arg1_type = ARG_PTR_TO_CTX, | |
2168 | .arg2_type = ARG_CONST_MAP_PTR, | |
2169 | .arg3_type = ARG_ANYTHING, | |
2170 | }; | |
2171 | ||
9383191d DB |
2172 | /* Stub for JITs that only support cBPF. eBPF programs are interpreted. |
2173 | * It is encouraged to implement bpf_int_jit_compile() instead, so that | |
2174 | * eBPF and implicitly also cBPF can get JITed! | |
2175 | */ | |
d1c55ab5 | 2176 | struct bpf_prog * __weak bpf_int_jit_compile(struct bpf_prog *prog) |
3324b584 | 2177 | { |
d1c55ab5 | 2178 | return prog; |
3324b584 DB |
2179 | } |
2180 | ||
9383191d DB |
2181 | /* Stub for JITs that support eBPF. All cBPF code gets transformed into |
2182 | * eBPF by the kernel and is later compiled by bpf_int_jit_compile(). | |
2183 | */ | |
2184 | void __weak bpf_jit_compile(struct bpf_prog *prog) | |
2185 | { | |
2186 | } | |
2187 | ||
17bedab2 | 2188 | bool __weak bpf_helper_changes_pkt_data(void *func) |
969bf05e AS |
2189 | { |
2190 | return false; | |
2191 | } | |
2192 | ||
a4b1d3c1 JW |
2193 | /* Return TRUE if the JIT backend wants verifier to enable sub-register usage |
2194 | * analysis code and wants explicit zero extension inserted by verifier. | |
2195 | * Otherwise, return FALSE. | |
2196 | */ | |
2197 | bool __weak bpf_jit_needs_zext(void) | |
2198 | { | |
2199 | return false; | |
2200 | } | |
2201 | ||
f89b7755 AS |
2202 | /* To execute LD_ABS/LD_IND instructions __bpf_prog_run() may call |
2203 | * skb_copy_bits(), so provide a weak definition of it for NET-less config. | |
2204 | */ | |
2205 | int __weak skb_copy_bits(const struct sk_buff *skb, int offset, void *to, | |
2206 | int len) | |
2207 | { | |
2208 | return -EFAULT; | |
2209 | } | |
a67edbf4 | 2210 | |
5964b200 AS |
2211 | int __weak bpf_arch_text_poke(void *ip, enum bpf_text_poke_type t, |
2212 | void *addr1, void *addr2) | |
2213 | { | |
2214 | return -ENOTSUPP; | |
2215 | } | |
2216 | ||
492ecee8 AS |
2217 | DEFINE_STATIC_KEY_FALSE(bpf_stats_enabled_key); |
2218 | EXPORT_SYMBOL(bpf_stats_enabled_key); | |
492ecee8 | 2219 | |
a67edbf4 DB |
2220 | /* All definitions of tracepoints related to BPF. */ |
2221 | #define CREATE_TRACE_POINTS | |
2222 | #include <linux/bpf_trace.h> | |
2223 | ||
2224 | EXPORT_TRACEPOINT_SYMBOL_GPL(xdp_exception); | |
e7d47989 | 2225 | EXPORT_TRACEPOINT_SYMBOL_GPL(xdp_bulk_tx); |