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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> |
00089c04 | 28 | #include <linux/objtool.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 | { |
ddf8503c | 80 | gfp_t gfp_flags = GFP_KERNEL_ACCOUNT | __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); | |
88dca4ca | 85 | fp = __vmalloc(size, gfp_flags); |
60a3b225 DB |
86 | if (fp == NULL) |
87 | return NULL; | |
88 | ||
ddf8503c | 89 | aux = kzalloc(sizeof(*aux), GFP_KERNEL_ACCOUNT | gfp_extra_flags); |
09756af4 | 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 | |
ecb60d1c | 100 | INIT_LIST_HEAD_RCU(&fp->aux->ksym.lnode); |
984fe94f | 101 | mutex_init(&fp->aux->used_maps_mutex); |
3aac1ead | 102 | mutex_init(&fp->aux->dst_mutex); |
74451e66 | 103 | |
60a3b225 DB |
104 | return fp; |
105 | } | |
492ecee8 AS |
106 | |
107 | struct bpf_prog *bpf_prog_alloc(unsigned int size, gfp_t gfp_extra_flags) | |
108 | { | |
ddf8503c | 109 | gfp_t gfp_flags = GFP_KERNEL_ACCOUNT | __GFP_ZERO | gfp_extra_flags; |
492ecee8 | 110 | struct bpf_prog *prog; |
4b911304 | 111 | int cpu; |
492ecee8 AS |
112 | |
113 | prog = bpf_prog_alloc_no_stats(size, gfp_extra_flags); | |
114 | if (!prog) | |
115 | return NULL; | |
116 | ||
117 | prog->aux->stats = alloc_percpu_gfp(struct bpf_prog_stats, gfp_flags); | |
118 | if (!prog->aux->stats) { | |
119 | kfree(prog->aux); | |
120 | vfree(prog); | |
121 | return NULL; | |
122 | } | |
123 | ||
4b911304 ED |
124 | for_each_possible_cpu(cpu) { |
125 | struct bpf_prog_stats *pstats; | |
126 | ||
127 | pstats = per_cpu_ptr(prog->aux->stats, cpu); | |
128 | u64_stats_init(&pstats->syncp); | |
129 | } | |
492ecee8 AS |
130 | return prog; |
131 | } | |
60a3b225 DB |
132 | EXPORT_SYMBOL_GPL(bpf_prog_alloc); |
133 | ||
c454a46b MKL |
134 | int bpf_prog_alloc_jited_linfo(struct bpf_prog *prog) |
135 | { | |
136 | if (!prog->aux->nr_linfo || !prog->jit_requested) | |
137 | return 0; | |
138 | ||
139 | prog->aux->jited_linfo = kcalloc(prog->aux->nr_linfo, | |
140 | sizeof(*prog->aux->jited_linfo), | |
ddf8503c | 141 | GFP_KERNEL_ACCOUNT | __GFP_NOWARN); |
c454a46b MKL |
142 | if (!prog->aux->jited_linfo) |
143 | return -ENOMEM; | |
144 | ||
145 | return 0; | |
146 | } | |
147 | ||
148 | void bpf_prog_free_jited_linfo(struct bpf_prog *prog) | |
149 | { | |
150 | kfree(prog->aux->jited_linfo); | |
151 | prog->aux->jited_linfo = NULL; | |
152 | } | |
153 | ||
154 | void bpf_prog_free_unused_jited_linfo(struct bpf_prog *prog) | |
155 | { | |
156 | if (prog->aux->jited_linfo && !prog->aux->jited_linfo[0]) | |
157 | bpf_prog_free_jited_linfo(prog); | |
158 | } | |
159 | ||
160 | /* The jit engine is responsible to provide an array | |
161 | * for insn_off to the jited_off mapping (insn_to_jit_off). | |
162 | * | |
163 | * The idx to this array is the insn_off. Hence, the insn_off | |
164 | * here is relative to the prog itself instead of the main prog. | |
165 | * This array has one entry for each xlated bpf insn. | |
166 | * | |
167 | * jited_off is the byte off to the last byte of the jited insn. | |
168 | * | |
169 | * Hence, with | |
170 | * insn_start: | |
171 | * The first bpf insn off of the prog. The insn off | |
172 | * here is relative to the main prog. | |
173 | * e.g. if prog is a subprog, insn_start > 0 | |
174 | * linfo_idx: | |
175 | * The prog's idx to prog->aux->linfo and jited_linfo | |
176 | * | |
177 | * jited_linfo[linfo_idx] = prog->bpf_func | |
178 | * | |
179 | * For i > linfo_idx, | |
180 | * | |
181 | * jited_linfo[i] = prog->bpf_func + | |
182 | * insn_to_jit_off[linfo[i].insn_off - insn_start - 1] | |
183 | */ | |
184 | void bpf_prog_fill_jited_linfo(struct bpf_prog *prog, | |
185 | const u32 *insn_to_jit_off) | |
186 | { | |
187 | u32 linfo_idx, insn_start, insn_end, nr_linfo, i; | |
188 | const struct bpf_line_info *linfo; | |
189 | void **jited_linfo; | |
190 | ||
191 | if (!prog->aux->jited_linfo) | |
192 | /* Userspace did not provide linfo */ | |
193 | return; | |
194 | ||
195 | linfo_idx = prog->aux->linfo_idx; | |
196 | linfo = &prog->aux->linfo[linfo_idx]; | |
197 | insn_start = linfo[0].insn_off; | |
198 | insn_end = insn_start + prog->len; | |
199 | ||
200 | jited_linfo = &prog->aux->jited_linfo[linfo_idx]; | |
201 | jited_linfo[0] = prog->bpf_func; | |
202 | ||
203 | nr_linfo = prog->aux->nr_linfo - linfo_idx; | |
204 | ||
205 | for (i = 1; i < nr_linfo && linfo[i].insn_off < insn_end; i++) | |
206 | /* The verifier ensures that linfo[i].insn_off is | |
207 | * strictly increasing | |
208 | */ | |
209 | jited_linfo[i] = prog->bpf_func + | |
210 | insn_to_jit_off[linfo[i].insn_off - insn_start - 1]; | |
211 | } | |
212 | ||
213 | void bpf_prog_free_linfo(struct bpf_prog *prog) | |
214 | { | |
215 | bpf_prog_free_jited_linfo(prog); | |
216 | kvfree(prog->aux->linfo); | |
217 | } | |
218 | ||
60a3b225 DB |
219 | struct bpf_prog *bpf_prog_realloc(struct bpf_prog *fp_old, unsigned int size, |
220 | gfp_t gfp_extra_flags) | |
221 | { | |
ddf8503c | 222 | gfp_t gfp_flags = GFP_KERNEL_ACCOUNT | __GFP_ZERO | gfp_extra_flags; |
60a3b225 | 223 | struct bpf_prog *fp; |
3ac1f01b | 224 | u32 pages; |
60a3b225 | 225 | |
60a3b225 | 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 | ||
88dca4ca | 231 | fp = __vmalloc(size, gfp_flags); |
3ac1f01b | 232 | if (fp) { |
60a3b225 | 233 | memcpy(fp, fp_old, fp_old->pages * PAGE_SIZE); |
5ccb071e | 234 | fp->pages = pages; |
e9d8afa9 | 235 | fp->aux->prog = fp; |
60a3b225 | 236 | |
09756af4 | 237 | /* We keep fp->aux from fp_old around in the new |
60a3b225 DB |
238 | * reallocated structure. |
239 | */ | |
09756af4 | 240 | fp_old->aux = NULL; |
60a3b225 DB |
241 | __bpf_prog_free(fp_old); |
242 | } | |
243 | ||
244 | return fp; | |
245 | } | |
60a3b225 DB |
246 | |
247 | void __bpf_prog_free(struct bpf_prog *fp) | |
248 | { | |
492ecee8 | 249 | if (fp->aux) { |
984fe94f | 250 | mutex_destroy(&fp->aux->used_maps_mutex); |
3aac1ead | 251 | mutex_destroy(&fp->aux->dst_mutex); |
492ecee8 | 252 | free_percpu(fp->aux->stats); |
a66886fe | 253 | kfree(fp->aux->poke_tab); |
492ecee8 AS |
254 | kfree(fp->aux); |
255 | } | |
60a3b225 DB |
256 | vfree(fp); |
257 | } | |
60a3b225 | 258 | |
f1f7714e | 259 | int bpf_prog_calc_tag(struct bpf_prog *fp) |
7bd509e3 | 260 | { |
6b0b0fa2 | 261 | const u32 bits_offset = SHA1_BLOCK_SIZE - sizeof(__be64); |
f1f7714e | 262 | u32 raw_size = bpf_prog_tag_scratch_size(fp); |
6b0b0fa2 EB |
263 | u32 digest[SHA1_DIGEST_WORDS]; |
264 | u32 ws[SHA1_WORKSPACE_WORDS]; | |
7bd509e3 | 265 | u32 i, bsize, psize, blocks; |
aafe6ae9 | 266 | struct bpf_insn *dst; |
7bd509e3 | 267 | bool was_ld_map; |
aafe6ae9 | 268 | u8 *raw, *todo; |
7bd509e3 DB |
269 | __be32 *result; |
270 | __be64 *bits; | |
271 | ||
aafe6ae9 DB |
272 | raw = vmalloc(raw_size); |
273 | if (!raw) | |
274 | return -ENOMEM; | |
275 | ||
6b0b0fa2 | 276 | sha1_init(digest); |
7bd509e3 DB |
277 | memset(ws, 0, sizeof(ws)); |
278 | ||
279 | /* We need to take out the map fd for the digest calculation | |
280 | * since they are unstable from user space side. | |
281 | */ | |
aafe6ae9 | 282 | dst = (void *)raw; |
7bd509e3 DB |
283 | for (i = 0, was_ld_map = false; i < fp->len; i++) { |
284 | dst[i] = fp->insnsi[i]; | |
285 | if (!was_ld_map && | |
286 | dst[i].code == (BPF_LD | BPF_IMM | BPF_DW) && | |
d8eca5bb DB |
287 | (dst[i].src_reg == BPF_PSEUDO_MAP_FD || |
288 | dst[i].src_reg == BPF_PSEUDO_MAP_VALUE)) { | |
7bd509e3 DB |
289 | was_ld_map = true; |
290 | dst[i].imm = 0; | |
291 | } else if (was_ld_map && | |
292 | dst[i].code == 0 && | |
293 | dst[i].dst_reg == 0 && | |
294 | dst[i].src_reg == 0 && | |
295 | dst[i].off == 0) { | |
296 | was_ld_map = false; | |
297 | dst[i].imm = 0; | |
298 | } else { | |
299 | was_ld_map = false; | |
300 | } | |
301 | } | |
302 | ||
aafe6ae9 DB |
303 | psize = bpf_prog_insn_size(fp); |
304 | memset(&raw[psize], 0, raw_size - psize); | |
7bd509e3 DB |
305 | raw[psize++] = 0x80; |
306 | ||
6b0b0fa2 EB |
307 | bsize = round_up(psize, SHA1_BLOCK_SIZE); |
308 | blocks = bsize / SHA1_BLOCK_SIZE; | |
aafe6ae9 | 309 | todo = raw; |
7bd509e3 DB |
310 | if (bsize - psize >= sizeof(__be64)) { |
311 | bits = (__be64 *)(todo + bsize - sizeof(__be64)); | |
312 | } else { | |
313 | bits = (__be64 *)(todo + bsize + bits_offset); | |
314 | blocks++; | |
315 | } | |
316 | *bits = cpu_to_be64((psize - 1) << 3); | |
317 | ||
318 | while (blocks--) { | |
6b0b0fa2 EB |
319 | sha1_transform(digest, todo, ws); |
320 | todo += SHA1_BLOCK_SIZE; | |
7bd509e3 DB |
321 | } |
322 | ||
f1f7714e | 323 | result = (__force __be32 *)digest; |
6b0b0fa2 | 324 | for (i = 0; i < SHA1_DIGEST_WORDS; i++) |
f1f7714e DB |
325 | result[i] = cpu_to_be32(digest[i]); |
326 | memcpy(fp->tag, result, sizeof(fp->tag)); | |
aafe6ae9 DB |
327 | |
328 | vfree(raw); | |
329 | return 0; | |
7bd509e3 DB |
330 | } |
331 | ||
2cbd95a5 | 332 | static int bpf_adj_delta_to_imm(struct bpf_insn *insn, u32 pos, s32 end_old, |
af959b18 | 333 | s32 end_new, s32 curr, const bool probe_pass) |
c237ee5e | 334 | { |
050fad7c | 335 | const s64 imm_min = S32_MIN, imm_max = S32_MAX; |
2cbd95a5 | 336 | s32 delta = end_new - end_old; |
050fad7c DB |
337 | s64 imm = insn->imm; |
338 | ||
2cbd95a5 | 339 | if (curr < pos && curr + imm + 1 >= end_old) |
050fad7c | 340 | imm += delta; |
2cbd95a5 | 341 | else if (curr >= end_new && curr + imm + 1 < end_new) |
050fad7c DB |
342 | imm -= delta; |
343 | if (imm < imm_min || imm > imm_max) | |
344 | return -ERANGE; | |
345 | if (!probe_pass) | |
346 | insn->imm = imm; | |
347 | return 0; | |
348 | } | |
349 | ||
2cbd95a5 | 350 | static int bpf_adj_delta_to_off(struct bpf_insn *insn, u32 pos, s32 end_old, |
af959b18 | 351 | s32 end_new, s32 curr, const bool probe_pass) |
050fad7c DB |
352 | { |
353 | const s32 off_min = S16_MIN, off_max = S16_MAX; | |
2cbd95a5 | 354 | s32 delta = end_new - end_old; |
050fad7c DB |
355 | s32 off = insn->off; |
356 | ||
2cbd95a5 | 357 | if (curr < pos && curr + off + 1 >= end_old) |
050fad7c | 358 | off += delta; |
2cbd95a5 | 359 | else if (curr >= end_new && curr + off + 1 < end_new) |
050fad7c DB |
360 | off -= delta; |
361 | if (off < off_min || off > off_max) | |
362 | return -ERANGE; | |
363 | if (!probe_pass) | |
364 | insn->off = off; | |
365 | return 0; | |
366 | } | |
367 | ||
2cbd95a5 JK |
368 | static int bpf_adj_branches(struct bpf_prog *prog, u32 pos, s32 end_old, |
369 | s32 end_new, const bool probe_pass) | |
050fad7c | 370 | { |
2cbd95a5 | 371 | u32 i, insn_cnt = prog->len + (probe_pass ? end_new - end_old : 0); |
c237ee5e | 372 | struct bpf_insn *insn = prog->insnsi; |
050fad7c | 373 | int ret = 0; |
c237ee5e DB |
374 | |
375 | for (i = 0; i < insn_cnt; i++, insn++) { | |
050fad7c DB |
376 | u8 code; |
377 | ||
378 | /* In the probing pass we still operate on the original, | |
379 | * unpatched image in order to check overflows before we | |
380 | * do any other adjustments. Therefore skip the patchlet. | |
381 | */ | |
382 | if (probe_pass && i == pos) { | |
2cbd95a5 JK |
383 | i = end_new; |
384 | insn = prog->insnsi + end_old; | |
050fad7c | 385 | } |
1ea47e01 | 386 | code = insn->code; |
092ed096 JW |
387 | if ((BPF_CLASS(code) != BPF_JMP && |
388 | BPF_CLASS(code) != BPF_JMP32) || | |
050fad7c | 389 | BPF_OP(code) == BPF_EXIT) |
1ea47e01 | 390 | continue; |
050fad7c | 391 | /* Adjust offset of jmps if we cross patch boundaries. */ |
1ea47e01 | 392 | if (BPF_OP(code) == BPF_CALL) { |
050fad7c | 393 | if (insn->src_reg != BPF_PSEUDO_CALL) |
1ea47e01 | 394 | continue; |
2cbd95a5 JK |
395 | ret = bpf_adj_delta_to_imm(insn, pos, end_old, |
396 | end_new, i, probe_pass); | |
1ea47e01 | 397 | } else { |
2cbd95a5 JK |
398 | ret = bpf_adj_delta_to_off(insn, pos, end_old, |
399 | end_new, i, probe_pass); | |
1ea47e01 | 400 | } |
050fad7c DB |
401 | if (ret) |
402 | break; | |
c237ee5e | 403 | } |
050fad7c DB |
404 | |
405 | return ret; | |
c237ee5e DB |
406 | } |
407 | ||
c454a46b MKL |
408 | static void bpf_adj_linfo(struct bpf_prog *prog, u32 off, u32 delta) |
409 | { | |
410 | struct bpf_line_info *linfo; | |
411 | u32 i, nr_linfo; | |
412 | ||
413 | nr_linfo = prog->aux->nr_linfo; | |
414 | if (!nr_linfo || !delta) | |
415 | return; | |
416 | ||
417 | linfo = prog->aux->linfo; | |
418 | ||
419 | for (i = 0; i < nr_linfo; i++) | |
420 | if (off < linfo[i].insn_off) | |
421 | break; | |
422 | ||
423 | /* Push all off < linfo[i].insn_off by delta */ | |
424 | for (; i < nr_linfo; i++) | |
425 | linfo[i].insn_off += delta; | |
426 | } | |
427 | ||
c237ee5e DB |
428 | struct bpf_prog *bpf_patch_insn_single(struct bpf_prog *prog, u32 off, |
429 | const struct bpf_insn *patch, u32 len) | |
430 | { | |
431 | u32 insn_adj_cnt, insn_rest, insn_delta = len - 1; | |
050fad7c | 432 | const u32 cnt_max = S16_MAX; |
c237ee5e | 433 | struct bpf_prog *prog_adj; |
4f73379e | 434 | int err; |
c237ee5e DB |
435 | |
436 | /* Since our patchlet doesn't expand the image, we're done. */ | |
437 | if (insn_delta == 0) { | |
438 | memcpy(prog->insnsi + off, patch, sizeof(*patch)); | |
439 | return prog; | |
440 | } | |
441 | ||
442 | insn_adj_cnt = prog->len + insn_delta; | |
443 | ||
050fad7c DB |
444 | /* Reject anything that would potentially let the insn->off |
445 | * target overflow when we have excessive program expansions. | |
446 | * We need to probe here before we do any reallocation where | |
447 | * we afterwards may not fail anymore. | |
448 | */ | |
449 | if (insn_adj_cnt > cnt_max && | |
4f73379e AS |
450 | (err = bpf_adj_branches(prog, off, off + 1, off + len, true))) |
451 | return ERR_PTR(err); | |
050fad7c | 452 | |
c237ee5e DB |
453 | /* Several new instructions need to be inserted. Make room |
454 | * for them. Likely, there's no need for a new allocation as | |
455 | * last page could have large enough tailroom. | |
456 | */ | |
457 | prog_adj = bpf_prog_realloc(prog, bpf_prog_size(insn_adj_cnt), | |
458 | GFP_USER); | |
459 | if (!prog_adj) | |
4f73379e | 460 | return ERR_PTR(-ENOMEM); |
c237ee5e DB |
461 | |
462 | prog_adj->len = insn_adj_cnt; | |
463 | ||
464 | /* Patching happens in 3 steps: | |
465 | * | |
466 | * 1) Move over tail of insnsi from next instruction onwards, | |
467 | * so we can patch the single target insn with one or more | |
468 | * new ones (patching is always from 1 to n insns, n > 0). | |
469 | * 2) Inject new instructions at the target location. | |
470 | * 3) Adjust branch offsets if necessary. | |
471 | */ | |
472 | insn_rest = insn_adj_cnt - off - len; | |
473 | ||
474 | memmove(prog_adj->insnsi + off + len, prog_adj->insnsi + off + 1, | |
475 | sizeof(*patch) * insn_rest); | |
476 | memcpy(prog_adj->insnsi + off, patch, sizeof(*patch) * len); | |
477 | ||
050fad7c DB |
478 | /* We are guaranteed to not fail at this point, otherwise |
479 | * the ship has sailed to reverse to the original state. An | |
480 | * overflow cannot happen at this point. | |
481 | */ | |
2cbd95a5 | 482 | BUG_ON(bpf_adj_branches(prog_adj, off, off + 1, off + len, false)); |
c237ee5e | 483 | |
c454a46b MKL |
484 | bpf_adj_linfo(prog_adj, off, insn_delta); |
485 | ||
c237ee5e DB |
486 | return prog_adj; |
487 | } | |
488 | ||
52875a04 JK |
489 | int bpf_remove_insns(struct bpf_prog *prog, u32 off, u32 cnt) |
490 | { | |
491 | /* Branch offsets can't overflow when program is shrinking, no need | |
492 | * to call bpf_adj_branches(..., true) here | |
493 | */ | |
494 | memmove(prog->insnsi + off, prog->insnsi + off + cnt, | |
495 | sizeof(struct bpf_insn) * (prog->len - off - cnt)); | |
496 | prog->len -= cnt; | |
497 | ||
498 | return WARN_ON_ONCE(bpf_adj_branches(prog, off, off + cnt, off, false)); | |
499 | } | |
500 | ||
cd7455f1 | 501 | static void bpf_prog_kallsyms_del_subprogs(struct bpf_prog *fp) |
7d1982b4 DB |
502 | { |
503 | int i; | |
504 | ||
505 | for (i = 0; i < fp->aux->func_cnt; i++) | |
506 | bpf_prog_kallsyms_del(fp->aux->func[i]); | |
507 | } | |
508 | ||
509 | void bpf_prog_kallsyms_del_all(struct bpf_prog *fp) | |
510 | { | |
511 | bpf_prog_kallsyms_del_subprogs(fp); | |
512 | bpf_prog_kallsyms_del(fp); | |
513 | } | |
514 | ||
b954d834 | 515 | #ifdef CONFIG_BPF_JIT |
fa9dd599 | 516 | /* All BPF JIT sysctl knobs here. */ |
81c22041 DB |
517 | int bpf_jit_enable __read_mostly = IS_BUILTIN(CONFIG_BPF_JIT_DEFAULT_ON); |
518 | int bpf_jit_kallsyms __read_mostly = IS_BUILTIN(CONFIG_BPF_JIT_DEFAULT_ON); | |
fa9dd599 | 519 | int bpf_jit_harden __read_mostly; |
fdadd049 | 520 | long bpf_jit_limit __read_mostly; |
fa9dd599 | 521 | |
535911c8 JO |
522 | static void |
523 | bpf_prog_ksym_set_addr(struct bpf_prog *prog) | |
74451e66 DB |
524 | { |
525 | const struct bpf_binary_header *hdr = bpf_jit_binary_hdr(prog); | |
526 | unsigned long addr = (unsigned long)hdr; | |
527 | ||
528 | WARN_ON_ONCE(!bpf_prog_ebpf_jited(prog)); | |
529 | ||
535911c8 JO |
530 | prog->aux->ksym.start = (unsigned long) prog->bpf_func; |
531 | prog->aux->ksym.end = addr + hdr->pages * PAGE_SIZE; | |
74451e66 DB |
532 | } |
533 | ||
bfea9a85 JO |
534 | static void |
535 | bpf_prog_ksym_set_name(struct bpf_prog *prog) | |
74451e66 | 536 | { |
bfea9a85 | 537 | char *sym = prog->aux->ksym.name; |
368211fb | 538 | const char *end = sym + KSYM_NAME_LEN; |
838e9690 YS |
539 | const struct btf_type *type; |
540 | const char *func_name; | |
368211fb | 541 | |
74451e66 | 542 | BUILD_BUG_ON(sizeof("bpf_prog_") + |
368211fb MKL |
543 | sizeof(prog->tag) * 2 + |
544 | /* name has been null terminated. | |
545 | * We should need +1 for the '_' preceding | |
546 | * the name. However, the null character | |
547 | * is double counted between the name and the | |
548 | * sizeof("bpf_prog_") above, so we omit | |
549 | * the +1 here. | |
550 | */ | |
551 | sizeof(prog->aux->name) > KSYM_NAME_LEN); | |
74451e66 DB |
552 | |
553 | sym += snprintf(sym, KSYM_NAME_LEN, "bpf_prog_"); | |
554 | sym = bin2hex(sym, prog->tag, sizeof(prog->tag)); | |
838e9690 YS |
555 | |
556 | /* prog->aux->name will be ignored if full btf name is available */ | |
7337224f | 557 | if (prog->aux->func_info_cnt) { |
ba64e7d8 YS |
558 | type = btf_type_by_id(prog->aux->btf, |
559 | prog->aux->func_info[prog->aux->func_idx].type_id); | |
838e9690 YS |
560 | func_name = btf_name_by_offset(prog->aux->btf, type->name_off); |
561 | snprintf(sym, (size_t)(end - sym), "_%s", func_name); | |
562 | return; | |
563 | } | |
564 | ||
368211fb MKL |
565 | if (prog->aux->name[0]) |
566 | snprintf(sym, (size_t)(end - sym), "_%s", prog->aux->name); | |
567 | else | |
568 | *sym = 0; | |
74451e66 DB |
569 | } |
570 | ||
ca4424c9 | 571 | static unsigned long bpf_get_ksym_start(struct latch_tree_node *n) |
74451e66 | 572 | { |
ca4424c9 | 573 | return container_of(n, struct bpf_ksym, tnode)->start; |
74451e66 DB |
574 | } |
575 | ||
576 | static __always_inline bool bpf_tree_less(struct latch_tree_node *a, | |
577 | struct latch_tree_node *b) | |
578 | { | |
ca4424c9 | 579 | return bpf_get_ksym_start(a) < bpf_get_ksym_start(b); |
74451e66 DB |
580 | } |
581 | ||
582 | static __always_inline int bpf_tree_comp(void *key, struct latch_tree_node *n) | |
583 | { | |
584 | unsigned long val = (unsigned long)key; | |
ca4424c9 | 585 | const struct bpf_ksym *ksym; |
74451e66 | 586 | |
ca4424c9 | 587 | ksym = container_of(n, struct bpf_ksym, tnode); |
74451e66 | 588 | |
ca4424c9 | 589 | if (val < ksym->start) |
74451e66 | 590 | return -1; |
ca4424c9 | 591 | if (val >= ksym->end) |
74451e66 DB |
592 | return 1; |
593 | ||
594 | return 0; | |
595 | } | |
596 | ||
597 | static const struct latch_tree_ops bpf_tree_ops = { | |
598 | .less = bpf_tree_less, | |
599 | .comp = bpf_tree_comp, | |
600 | }; | |
601 | ||
602 | static DEFINE_SPINLOCK(bpf_lock); | |
603 | static LIST_HEAD(bpf_kallsyms); | |
604 | static struct latch_tree_root bpf_tree __cacheline_aligned; | |
605 | ||
dba122fb | 606 | void bpf_ksym_add(struct bpf_ksym *ksym) |
74451e66 | 607 | { |
dba122fb JO |
608 | spin_lock_bh(&bpf_lock); |
609 | WARN_ON_ONCE(!list_empty(&ksym->lnode)); | |
610 | list_add_tail_rcu(&ksym->lnode, &bpf_kallsyms); | |
611 | latch_tree_insert(&ksym->tnode, &bpf_tree, &bpf_tree_ops); | |
612 | spin_unlock_bh(&bpf_lock); | |
74451e66 DB |
613 | } |
614 | ||
dba122fb | 615 | static void __bpf_ksym_del(struct bpf_ksym *ksym) |
74451e66 | 616 | { |
dba122fb | 617 | if (list_empty(&ksym->lnode)) |
74451e66 DB |
618 | return; |
619 | ||
dba122fb JO |
620 | latch_tree_erase(&ksym->tnode, &bpf_tree, &bpf_tree_ops); |
621 | list_del_rcu(&ksym->lnode); | |
622 | } | |
623 | ||
624 | void bpf_ksym_del(struct bpf_ksym *ksym) | |
625 | { | |
626 | spin_lock_bh(&bpf_lock); | |
627 | __bpf_ksym_del(ksym); | |
628 | spin_unlock_bh(&bpf_lock); | |
74451e66 DB |
629 | } |
630 | ||
631 | static bool bpf_prog_kallsyms_candidate(const struct bpf_prog *fp) | |
632 | { | |
633 | return fp->jited && !bpf_prog_was_classic(fp); | |
634 | } | |
635 | ||
636 | static bool bpf_prog_kallsyms_verify_off(const struct bpf_prog *fp) | |
637 | { | |
ecb60d1c JO |
638 | return list_empty(&fp->aux->ksym.lnode) || |
639 | fp->aux->ksym.lnode.prev == LIST_POISON2; | |
74451e66 DB |
640 | } |
641 | ||
642 | void bpf_prog_kallsyms_add(struct bpf_prog *fp) | |
643 | { | |
74451e66 | 644 | if (!bpf_prog_kallsyms_candidate(fp) || |
2c78ee89 | 645 | !bpf_capable()) |
74451e66 DB |
646 | return; |
647 | ||
535911c8 | 648 | bpf_prog_ksym_set_addr(fp); |
bfea9a85 | 649 | bpf_prog_ksym_set_name(fp); |
cbd76f8d | 650 | fp->aux->ksym.prog = true; |
535911c8 | 651 | |
dba122fb | 652 | bpf_ksym_add(&fp->aux->ksym); |
74451e66 DB |
653 | } |
654 | ||
655 | void bpf_prog_kallsyms_del(struct bpf_prog *fp) | |
656 | { | |
74451e66 DB |
657 | if (!bpf_prog_kallsyms_candidate(fp)) |
658 | return; | |
659 | ||
dba122fb | 660 | bpf_ksym_del(&fp->aux->ksym); |
74451e66 DB |
661 | } |
662 | ||
eda0c929 JO |
663 | static struct bpf_ksym *bpf_ksym_find(unsigned long addr) |
664 | { | |
665 | struct latch_tree_node *n; | |
666 | ||
667 | n = latch_tree_find((void *)addr, &bpf_tree, &bpf_tree_ops); | |
668 | return n ? container_of(n, struct bpf_ksym, tnode) : NULL; | |
669 | } | |
670 | ||
74451e66 DB |
671 | const char *__bpf_address_lookup(unsigned long addr, unsigned long *size, |
672 | unsigned long *off, char *sym) | |
673 | { | |
eda0c929 | 674 | struct bpf_ksym *ksym; |
74451e66 DB |
675 | char *ret = NULL; |
676 | ||
677 | rcu_read_lock(); | |
eda0c929 JO |
678 | ksym = bpf_ksym_find(addr); |
679 | if (ksym) { | |
680 | unsigned long symbol_start = ksym->start; | |
681 | unsigned long symbol_end = ksym->end; | |
535911c8 | 682 | |
eda0c929 | 683 | strncpy(sym, ksym->name, KSYM_NAME_LEN); |
74451e66 DB |
684 | |
685 | ret = sym; | |
686 | if (size) | |
687 | *size = symbol_end - symbol_start; | |
688 | if (off) | |
689 | *off = addr - symbol_start; | |
690 | } | |
691 | rcu_read_unlock(); | |
692 | ||
693 | return ret; | |
694 | } | |
695 | ||
696 | bool is_bpf_text_address(unsigned long addr) | |
697 | { | |
698 | bool ret; | |
699 | ||
700 | rcu_read_lock(); | |
eda0c929 | 701 | ret = bpf_ksym_find(addr) != NULL; |
74451e66 DB |
702 | rcu_read_unlock(); |
703 | ||
704 | return ret; | |
705 | } | |
706 | ||
cbd76f8d JO |
707 | static struct bpf_prog *bpf_prog_ksym_find(unsigned long addr) |
708 | { | |
709 | struct bpf_ksym *ksym = bpf_ksym_find(addr); | |
710 | ||
711 | return ksym && ksym->prog ? | |
712 | container_of(ksym, struct bpf_prog_aux, ksym)->prog : | |
713 | NULL; | |
714 | } | |
715 | ||
3dec541b AS |
716 | const struct exception_table_entry *search_bpf_extables(unsigned long addr) |
717 | { | |
718 | const struct exception_table_entry *e = NULL; | |
719 | struct bpf_prog *prog; | |
720 | ||
721 | rcu_read_lock(); | |
cbd76f8d | 722 | prog = bpf_prog_ksym_find(addr); |
3dec541b AS |
723 | if (!prog) |
724 | goto out; | |
725 | if (!prog->aux->num_exentries) | |
726 | goto out; | |
727 | ||
728 | e = search_extable(prog->aux->extable, prog->aux->num_exentries, addr); | |
729 | out: | |
730 | rcu_read_unlock(); | |
731 | return e; | |
732 | } | |
733 | ||
74451e66 DB |
734 | int bpf_get_kallsym(unsigned int symnum, unsigned long *value, char *type, |
735 | char *sym) | |
736 | { | |
ecb60d1c | 737 | struct bpf_ksym *ksym; |
74451e66 DB |
738 | unsigned int it = 0; |
739 | int ret = -ERANGE; | |
740 | ||
741 | if (!bpf_jit_kallsyms_enabled()) | |
742 | return ret; | |
743 | ||
744 | rcu_read_lock(); | |
ecb60d1c | 745 | list_for_each_entry_rcu(ksym, &bpf_kallsyms, lnode) { |
74451e66 DB |
746 | if (it++ != symnum) |
747 | continue; | |
748 | ||
ecb60d1c | 749 | strncpy(sym, ksym->name, KSYM_NAME_LEN); |
74451e66 | 750 | |
ecb60d1c | 751 | *value = ksym->start; |
74451e66 DB |
752 | *type = BPF_SYM_ELF_TYPE; |
753 | ||
754 | ret = 0; | |
755 | break; | |
756 | } | |
757 | rcu_read_unlock(); | |
758 | ||
759 | return ret; | |
760 | } | |
761 | ||
a66886fe DB |
762 | int bpf_jit_add_poke_descriptor(struct bpf_prog *prog, |
763 | struct bpf_jit_poke_descriptor *poke) | |
764 | { | |
765 | struct bpf_jit_poke_descriptor *tab = prog->aux->poke_tab; | |
766 | static const u32 poke_tab_max = 1024; | |
767 | u32 slot = prog->aux->size_poke_tab; | |
768 | u32 size = slot + 1; | |
769 | ||
770 | if (size > poke_tab_max) | |
771 | return -ENOSPC; | |
cf71b174 | 772 | if (poke->tailcall_target || poke->tailcall_target_stable || |
ebf7d1f5 | 773 | poke->tailcall_bypass || poke->adj_off || poke->bypass_addr) |
a66886fe DB |
774 | return -EINVAL; |
775 | ||
776 | switch (poke->reason) { | |
777 | case BPF_POKE_REASON_TAIL_CALL: | |
778 | if (!poke->tail_call.map) | |
779 | return -EINVAL; | |
780 | break; | |
781 | default: | |
782 | return -EINVAL; | |
783 | } | |
784 | ||
785 | tab = krealloc(tab, size * sizeof(*poke), GFP_KERNEL); | |
786 | if (!tab) | |
787 | return -ENOMEM; | |
788 | ||
789 | memcpy(&tab[slot], poke, sizeof(*poke)); | |
790 | prog->aux->size_poke_tab = size; | |
791 | prog->aux->poke_tab = tab; | |
792 | ||
793 | return slot; | |
794 | } | |
795 | ||
ede95a63 DB |
796 | static atomic_long_t bpf_jit_current; |
797 | ||
fdadd049 DB |
798 | /* Can be overridden by an arch's JIT compiler if it has a custom, |
799 | * dedicated BPF backend memory area, or if neither of the two | |
800 | * below apply. | |
801 | */ | |
802 | u64 __weak bpf_jit_alloc_exec_limit(void) | |
803 | { | |
ede95a63 | 804 | #if defined(MODULES_VADDR) |
fdadd049 DB |
805 | return MODULES_END - MODULES_VADDR; |
806 | #else | |
807 | return VMALLOC_END - VMALLOC_START; | |
808 | #endif | |
809 | } | |
810 | ||
ede95a63 DB |
811 | static int __init bpf_jit_charge_init(void) |
812 | { | |
813 | /* Only used as heuristic here to derive limit. */ | |
fdadd049 DB |
814 | bpf_jit_limit = min_t(u64, round_up(bpf_jit_alloc_exec_limit() >> 2, |
815 | PAGE_SIZE), LONG_MAX); | |
ede95a63 DB |
816 | return 0; |
817 | } | |
818 | pure_initcall(bpf_jit_charge_init); | |
ede95a63 | 819 | |
b9fe5bd1 | 820 | int bpf_jit_charge_modmem(u32 pages) |
ede95a63 DB |
821 | { |
822 | if (atomic_long_add_return(pages, &bpf_jit_current) > | |
823 | (bpf_jit_limit >> PAGE_SHIFT)) { | |
824 | if (!capable(CAP_SYS_ADMIN)) { | |
825 | atomic_long_sub(pages, &bpf_jit_current); | |
826 | return -EPERM; | |
827 | } | |
828 | } | |
829 | ||
830 | return 0; | |
831 | } | |
832 | ||
b9fe5bd1 | 833 | void bpf_jit_uncharge_modmem(u32 pages) |
ede95a63 DB |
834 | { |
835 | atomic_long_sub(pages, &bpf_jit_current); | |
836 | } | |
837 | ||
dc002bb6 AB |
838 | void *__weak bpf_jit_alloc_exec(unsigned long size) |
839 | { | |
840 | return module_alloc(size); | |
841 | } | |
842 | ||
843 | void __weak bpf_jit_free_exec(void *addr) | |
844 | { | |
845 | module_memfree(addr); | |
846 | } | |
847 | ||
738cbe72 DB |
848 | struct bpf_binary_header * |
849 | bpf_jit_binary_alloc(unsigned int proglen, u8 **image_ptr, | |
850 | unsigned int alignment, | |
851 | bpf_jit_fill_hole_t bpf_fill_ill_insns) | |
852 | { | |
853 | struct bpf_binary_header *hdr; | |
ede95a63 | 854 | u32 size, hole, start, pages; |
738cbe72 | 855 | |
b7b3fc8d IL |
856 | WARN_ON_ONCE(!is_power_of_2(alignment) || |
857 | alignment > BPF_IMAGE_ALIGNMENT); | |
858 | ||
738cbe72 DB |
859 | /* Most of BPF filters are really small, but if some of them |
860 | * fill a page, allow at least 128 extra bytes to insert a | |
861 | * random section of illegal instructions. | |
862 | */ | |
863 | size = round_up(proglen + sizeof(*hdr) + 128, PAGE_SIZE); | |
ede95a63 DB |
864 | pages = size / PAGE_SIZE; |
865 | ||
866 | if (bpf_jit_charge_modmem(pages)) | |
867 | return NULL; | |
dc002bb6 | 868 | hdr = bpf_jit_alloc_exec(size); |
ede95a63 DB |
869 | if (!hdr) { |
870 | bpf_jit_uncharge_modmem(pages); | |
738cbe72 | 871 | return NULL; |
ede95a63 | 872 | } |
738cbe72 DB |
873 | |
874 | /* Fill space with illegal/arch-dep instructions. */ | |
875 | bpf_fill_ill_insns(hdr, size); | |
876 | ||
ede95a63 | 877 | hdr->pages = pages; |
738cbe72 DB |
878 | hole = min_t(unsigned int, size - (proglen + sizeof(*hdr)), |
879 | PAGE_SIZE - sizeof(*hdr)); | |
b7552e1b | 880 | start = (get_random_int() % hole) & ~(alignment - 1); |
738cbe72 DB |
881 | |
882 | /* Leave a random number of instructions before BPF code. */ | |
883 | *image_ptr = &hdr->image[start]; | |
884 | ||
885 | return hdr; | |
886 | } | |
887 | ||
888 | void bpf_jit_binary_free(struct bpf_binary_header *hdr) | |
889 | { | |
ede95a63 DB |
890 | u32 pages = hdr->pages; |
891 | ||
dc002bb6 | 892 | bpf_jit_free_exec(hdr); |
ede95a63 | 893 | bpf_jit_uncharge_modmem(pages); |
738cbe72 | 894 | } |
4f3446bb | 895 | |
74451e66 DB |
896 | /* This symbol is only overridden by archs that have different |
897 | * requirements than the usual eBPF JITs, f.e. when they only | |
898 | * implement cBPF JIT, do not set images read-only, etc. | |
899 | */ | |
900 | void __weak bpf_jit_free(struct bpf_prog *fp) | |
901 | { | |
902 | if (fp->jited) { | |
903 | struct bpf_binary_header *hdr = bpf_jit_binary_hdr(fp); | |
904 | ||
74451e66 DB |
905 | bpf_jit_binary_free(hdr); |
906 | ||
907 | WARN_ON_ONCE(!bpf_prog_kallsyms_verify_off(fp)); | |
908 | } | |
909 | ||
910 | bpf_prog_unlock_free(fp); | |
911 | } | |
912 | ||
e2c95a61 DB |
913 | int bpf_jit_get_func_addr(const struct bpf_prog *prog, |
914 | const struct bpf_insn *insn, bool extra_pass, | |
915 | u64 *func_addr, bool *func_addr_fixed) | |
916 | { | |
917 | s16 off = insn->off; | |
918 | s32 imm = insn->imm; | |
919 | u8 *addr; | |
920 | ||
921 | *func_addr_fixed = insn->src_reg != BPF_PSEUDO_CALL; | |
922 | if (!*func_addr_fixed) { | |
923 | /* Place-holder address till the last pass has collected | |
924 | * all addresses for JITed subprograms in which case we | |
925 | * can pick them up from prog->aux. | |
926 | */ | |
927 | if (!extra_pass) | |
928 | addr = NULL; | |
929 | else if (prog->aux->func && | |
930 | off >= 0 && off < prog->aux->func_cnt) | |
931 | addr = (u8 *)prog->aux->func[off]->bpf_func; | |
932 | else | |
933 | return -EINVAL; | |
934 | } else { | |
935 | /* Address of a BPF helper call. Since part of the core | |
936 | * kernel, it's always at a fixed location. __bpf_call_base | |
937 | * and the helper with imm relative to it are both in core | |
938 | * kernel. | |
939 | */ | |
940 | addr = (u8 *)__bpf_call_base + imm; | |
941 | } | |
942 | ||
943 | *func_addr = (unsigned long)addr; | |
944 | return 0; | |
945 | } | |
946 | ||
4f3446bb DB |
947 | static int bpf_jit_blind_insn(const struct bpf_insn *from, |
948 | const struct bpf_insn *aux, | |
ede7c460 NR |
949 | struct bpf_insn *to_buff, |
950 | bool emit_zext) | |
4f3446bb DB |
951 | { |
952 | struct bpf_insn *to = to_buff; | |
b7552e1b | 953 | u32 imm_rnd = get_random_int(); |
4f3446bb DB |
954 | s16 off; |
955 | ||
956 | BUILD_BUG_ON(BPF_REG_AX + 1 != MAX_BPF_JIT_REG); | |
957 | BUILD_BUG_ON(MAX_BPF_REG + 1 != MAX_BPF_JIT_REG); | |
958 | ||
9b73bfdd DB |
959 | /* Constraints on AX register: |
960 | * | |
961 | * AX register is inaccessible from user space. It is mapped in | |
962 | * all JITs, and used here for constant blinding rewrites. It is | |
963 | * typically "stateless" meaning its contents are only valid within | |
964 | * the executed instruction, but not across several instructions. | |
965 | * There are a few exceptions however which are further detailed | |
966 | * below. | |
967 | * | |
968 | * Constant blinding is only used by JITs, not in the interpreter. | |
969 | * The interpreter uses AX in some occasions as a local temporary | |
970 | * register e.g. in DIV or MOD instructions. | |
971 | * | |
972 | * In restricted circumstances, the verifier can also use the AX | |
973 | * register for rewrites as long as they do not interfere with | |
974 | * the above cases! | |
975 | */ | |
976 | if (from->dst_reg == BPF_REG_AX || from->src_reg == BPF_REG_AX) | |
977 | goto out; | |
978 | ||
4f3446bb DB |
979 | if (from->imm == 0 && |
980 | (from->code == (BPF_ALU | BPF_MOV | BPF_K) || | |
981 | from->code == (BPF_ALU64 | BPF_MOV | BPF_K))) { | |
982 | *to++ = BPF_ALU64_REG(BPF_XOR, from->dst_reg, from->dst_reg); | |
983 | goto out; | |
984 | } | |
985 | ||
986 | switch (from->code) { | |
987 | case BPF_ALU | BPF_ADD | BPF_K: | |
988 | case BPF_ALU | BPF_SUB | BPF_K: | |
989 | case BPF_ALU | BPF_AND | BPF_K: | |
990 | case BPF_ALU | BPF_OR | BPF_K: | |
991 | case BPF_ALU | BPF_XOR | BPF_K: | |
992 | case BPF_ALU | BPF_MUL | BPF_K: | |
993 | case BPF_ALU | BPF_MOV | BPF_K: | |
994 | case BPF_ALU | BPF_DIV | BPF_K: | |
995 | case BPF_ALU | BPF_MOD | BPF_K: | |
996 | *to++ = BPF_ALU32_IMM(BPF_MOV, BPF_REG_AX, imm_rnd ^ from->imm); | |
997 | *to++ = BPF_ALU32_IMM(BPF_XOR, BPF_REG_AX, imm_rnd); | |
998 | *to++ = BPF_ALU32_REG(from->code, from->dst_reg, BPF_REG_AX); | |
999 | break; | |
1000 | ||
1001 | case BPF_ALU64 | BPF_ADD | BPF_K: | |
1002 | case BPF_ALU64 | BPF_SUB | BPF_K: | |
1003 | case BPF_ALU64 | BPF_AND | BPF_K: | |
1004 | case BPF_ALU64 | BPF_OR | BPF_K: | |
1005 | case BPF_ALU64 | BPF_XOR | BPF_K: | |
1006 | case BPF_ALU64 | BPF_MUL | BPF_K: | |
1007 | case BPF_ALU64 | BPF_MOV | BPF_K: | |
1008 | case BPF_ALU64 | BPF_DIV | BPF_K: | |
1009 | case BPF_ALU64 | BPF_MOD | BPF_K: | |
1010 | *to++ = BPF_ALU64_IMM(BPF_MOV, BPF_REG_AX, imm_rnd ^ from->imm); | |
1011 | *to++ = BPF_ALU64_IMM(BPF_XOR, BPF_REG_AX, imm_rnd); | |
1012 | *to++ = BPF_ALU64_REG(from->code, from->dst_reg, BPF_REG_AX); | |
1013 | break; | |
1014 | ||
1015 | case BPF_JMP | BPF_JEQ | BPF_K: | |
1016 | case BPF_JMP | BPF_JNE | BPF_K: | |
1017 | case BPF_JMP | BPF_JGT | BPF_K: | |
92b31a9a | 1018 | case BPF_JMP | BPF_JLT | BPF_K: |
4f3446bb | 1019 | case BPF_JMP | BPF_JGE | BPF_K: |
92b31a9a | 1020 | case BPF_JMP | BPF_JLE | BPF_K: |
4f3446bb | 1021 | case BPF_JMP | BPF_JSGT | BPF_K: |
92b31a9a | 1022 | case BPF_JMP | BPF_JSLT | BPF_K: |
4f3446bb | 1023 | case BPF_JMP | BPF_JSGE | BPF_K: |
92b31a9a | 1024 | case BPF_JMP | BPF_JSLE | BPF_K: |
4f3446bb DB |
1025 | case BPF_JMP | BPF_JSET | BPF_K: |
1026 | /* Accommodate for extra offset in case of a backjump. */ | |
1027 | off = from->off; | |
1028 | if (off < 0) | |
1029 | off -= 2; | |
1030 | *to++ = BPF_ALU64_IMM(BPF_MOV, BPF_REG_AX, imm_rnd ^ from->imm); | |
1031 | *to++ = BPF_ALU64_IMM(BPF_XOR, BPF_REG_AX, imm_rnd); | |
1032 | *to++ = BPF_JMP_REG(from->code, from->dst_reg, BPF_REG_AX, off); | |
1033 | break; | |
1034 | ||
a7b76c88 JW |
1035 | case BPF_JMP32 | BPF_JEQ | BPF_K: |
1036 | case BPF_JMP32 | BPF_JNE | BPF_K: | |
1037 | case BPF_JMP32 | BPF_JGT | BPF_K: | |
1038 | case BPF_JMP32 | BPF_JLT | BPF_K: | |
1039 | case BPF_JMP32 | BPF_JGE | BPF_K: | |
1040 | case BPF_JMP32 | BPF_JLE | BPF_K: | |
1041 | case BPF_JMP32 | BPF_JSGT | BPF_K: | |
1042 | case BPF_JMP32 | BPF_JSLT | BPF_K: | |
1043 | case BPF_JMP32 | BPF_JSGE | BPF_K: | |
1044 | case BPF_JMP32 | BPF_JSLE | BPF_K: | |
1045 | case BPF_JMP32 | BPF_JSET | BPF_K: | |
1046 | /* Accommodate for extra offset in case of a backjump. */ | |
1047 | off = from->off; | |
1048 | if (off < 0) | |
1049 | off -= 2; | |
1050 | *to++ = BPF_ALU32_IMM(BPF_MOV, BPF_REG_AX, imm_rnd ^ from->imm); | |
1051 | *to++ = BPF_ALU32_IMM(BPF_XOR, BPF_REG_AX, imm_rnd); | |
1052 | *to++ = BPF_JMP32_REG(from->code, from->dst_reg, BPF_REG_AX, | |
1053 | off); | |
1054 | break; | |
1055 | ||
4f3446bb DB |
1056 | case BPF_LD | BPF_IMM | BPF_DW: |
1057 | *to++ = BPF_ALU64_IMM(BPF_MOV, BPF_REG_AX, imm_rnd ^ aux[1].imm); | |
1058 | *to++ = BPF_ALU64_IMM(BPF_XOR, BPF_REG_AX, imm_rnd); | |
1059 | *to++ = BPF_ALU64_IMM(BPF_LSH, BPF_REG_AX, 32); | |
1060 | *to++ = BPF_ALU64_REG(BPF_MOV, aux[0].dst_reg, BPF_REG_AX); | |
1061 | break; | |
1062 | case 0: /* Part 2 of BPF_LD | BPF_IMM | BPF_DW. */ | |
1063 | *to++ = BPF_ALU32_IMM(BPF_MOV, BPF_REG_AX, imm_rnd ^ aux[0].imm); | |
1064 | *to++ = BPF_ALU32_IMM(BPF_XOR, BPF_REG_AX, imm_rnd); | |
ede7c460 NR |
1065 | if (emit_zext) |
1066 | *to++ = BPF_ZEXT_REG(BPF_REG_AX); | |
4f3446bb DB |
1067 | *to++ = BPF_ALU64_REG(BPF_OR, aux[0].dst_reg, BPF_REG_AX); |
1068 | break; | |
1069 | ||
1070 | case BPF_ST | BPF_MEM | BPF_DW: | |
1071 | case BPF_ST | BPF_MEM | BPF_W: | |
1072 | case BPF_ST | BPF_MEM | BPF_H: | |
1073 | case BPF_ST | BPF_MEM | BPF_B: | |
1074 | *to++ = BPF_ALU64_IMM(BPF_MOV, BPF_REG_AX, imm_rnd ^ from->imm); | |
1075 | *to++ = BPF_ALU64_IMM(BPF_XOR, BPF_REG_AX, imm_rnd); | |
1076 | *to++ = BPF_STX_MEM(from->code, from->dst_reg, BPF_REG_AX, from->off); | |
1077 | break; | |
1078 | } | |
1079 | out: | |
1080 | return to - to_buff; | |
1081 | } | |
1082 | ||
1083 | static struct bpf_prog *bpf_prog_clone_create(struct bpf_prog *fp_other, | |
1084 | gfp_t gfp_extra_flags) | |
1085 | { | |
19809c2d | 1086 | gfp_t gfp_flags = GFP_KERNEL | __GFP_ZERO | gfp_extra_flags; |
4f3446bb DB |
1087 | struct bpf_prog *fp; |
1088 | ||
88dca4ca | 1089 | fp = __vmalloc(fp_other->pages * PAGE_SIZE, gfp_flags); |
4f3446bb | 1090 | if (fp != NULL) { |
4f3446bb DB |
1091 | /* aux->prog still points to the fp_other one, so |
1092 | * when promoting the clone to the real program, | |
1093 | * this still needs to be adapted. | |
1094 | */ | |
1095 | memcpy(fp, fp_other, fp_other->pages * PAGE_SIZE); | |
1096 | } | |
1097 | ||
1098 | return fp; | |
1099 | } | |
1100 | ||
1101 | static void bpf_prog_clone_free(struct bpf_prog *fp) | |
1102 | { | |
1103 | /* aux was stolen by the other clone, so we cannot free | |
1104 | * it from this path! It will be freed eventually by the | |
1105 | * other program on release. | |
1106 | * | |
1107 | * At this point, we don't need a deferred release since | |
1108 | * clone is guaranteed to not be locked. | |
1109 | */ | |
1110 | fp->aux = NULL; | |
1111 | __bpf_prog_free(fp); | |
1112 | } | |
1113 | ||
1114 | void bpf_jit_prog_release_other(struct bpf_prog *fp, struct bpf_prog *fp_other) | |
1115 | { | |
1116 | /* We have to repoint aux->prog to self, as we don't | |
1117 | * know whether fp here is the clone or the original. | |
1118 | */ | |
1119 | fp->aux->prog = fp; | |
1120 | bpf_prog_clone_free(fp_other); | |
1121 | } | |
1122 | ||
1123 | struct bpf_prog *bpf_jit_blind_constants(struct bpf_prog *prog) | |
1124 | { | |
1125 | struct bpf_insn insn_buff[16], aux[2]; | |
1126 | struct bpf_prog *clone, *tmp; | |
1127 | int insn_delta, insn_cnt; | |
1128 | struct bpf_insn *insn; | |
1129 | int i, rewritten; | |
1130 | ||
1c2a088a | 1131 | if (!bpf_jit_blinding_enabled(prog) || prog->blinded) |
4f3446bb DB |
1132 | return prog; |
1133 | ||
1134 | clone = bpf_prog_clone_create(prog, GFP_USER); | |
1135 | if (!clone) | |
1136 | return ERR_PTR(-ENOMEM); | |
1137 | ||
1138 | insn_cnt = clone->len; | |
1139 | insn = clone->insnsi; | |
1140 | ||
1141 | for (i = 0; i < insn_cnt; i++, insn++) { | |
1142 | /* We temporarily need to hold the original ld64 insn | |
1143 | * so that we can still access the first part in the | |
1144 | * second blinding run. | |
1145 | */ | |
1146 | if (insn[0].code == (BPF_LD | BPF_IMM | BPF_DW) && | |
1147 | insn[1].code == 0) | |
1148 | memcpy(aux, insn, sizeof(aux)); | |
1149 | ||
ede7c460 NR |
1150 | rewritten = bpf_jit_blind_insn(insn, aux, insn_buff, |
1151 | clone->aux->verifier_zext); | |
4f3446bb DB |
1152 | if (!rewritten) |
1153 | continue; | |
1154 | ||
1155 | tmp = bpf_patch_insn_single(clone, i, insn_buff, rewritten); | |
4f73379e | 1156 | if (IS_ERR(tmp)) { |
4f3446bb DB |
1157 | /* Patching may have repointed aux->prog during |
1158 | * realloc from the original one, so we need to | |
1159 | * fix it up here on error. | |
1160 | */ | |
1161 | bpf_jit_prog_release_other(prog, clone); | |
4f73379e | 1162 | return tmp; |
4f3446bb DB |
1163 | } |
1164 | ||
1165 | clone = tmp; | |
1166 | insn_delta = rewritten - 1; | |
1167 | ||
1168 | /* Walk new program and skip insns we just inserted. */ | |
1169 | insn = clone->insnsi + i + insn_delta; | |
1170 | insn_cnt += insn_delta; | |
1171 | i += insn_delta; | |
1172 | } | |
1173 | ||
1c2a088a | 1174 | clone->blinded = 1; |
4f3446bb DB |
1175 | return clone; |
1176 | } | |
b954d834 | 1177 | #endif /* CONFIG_BPF_JIT */ |
738cbe72 | 1178 | |
f5bffecd AS |
1179 | /* Base function for offset calculation. Needs to go into .text section, |
1180 | * therefore keeping it non-static as well; will also be used by JITs | |
7105e828 DB |
1181 | * anyway later on, so do not let the compiler omit it. This also needs |
1182 | * to go into kallsyms for correlation from e.g. bpftool, so naming | |
1183 | * must not change. | |
f5bffecd AS |
1184 | */ |
1185 | noinline u64 __bpf_call_base(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5) | |
1186 | { | |
1187 | return 0; | |
1188 | } | |
4d9c5c53 | 1189 | EXPORT_SYMBOL_GPL(__bpf_call_base); |
f5bffecd | 1190 | |
5e581dad DB |
1191 | /* All UAPI available opcodes. */ |
1192 | #define BPF_INSN_MAP(INSN_2, INSN_3) \ | |
1193 | /* 32 bit ALU operations. */ \ | |
1194 | /* Register based. */ \ | |
2dc6b100 JW |
1195 | INSN_3(ALU, ADD, X), \ |
1196 | INSN_3(ALU, SUB, X), \ | |
1197 | INSN_3(ALU, AND, X), \ | |
1198 | INSN_3(ALU, OR, X), \ | |
1199 | INSN_3(ALU, LSH, X), \ | |
1200 | INSN_3(ALU, RSH, X), \ | |
1201 | INSN_3(ALU, XOR, X), \ | |
1202 | INSN_3(ALU, MUL, X), \ | |
1203 | INSN_3(ALU, MOV, X), \ | |
1204 | INSN_3(ALU, ARSH, X), \ | |
1205 | INSN_3(ALU, DIV, X), \ | |
1206 | INSN_3(ALU, MOD, X), \ | |
5e581dad DB |
1207 | INSN_2(ALU, NEG), \ |
1208 | INSN_3(ALU, END, TO_BE), \ | |
1209 | INSN_3(ALU, END, TO_LE), \ | |
1210 | /* Immediate based. */ \ | |
2dc6b100 JW |
1211 | INSN_3(ALU, ADD, K), \ |
1212 | INSN_3(ALU, SUB, K), \ | |
1213 | INSN_3(ALU, AND, K), \ | |
1214 | INSN_3(ALU, OR, K), \ | |
1215 | INSN_3(ALU, LSH, K), \ | |
1216 | INSN_3(ALU, RSH, K), \ | |
1217 | INSN_3(ALU, XOR, K), \ | |
1218 | INSN_3(ALU, MUL, K), \ | |
1219 | INSN_3(ALU, MOV, K), \ | |
1220 | INSN_3(ALU, ARSH, K), \ | |
1221 | INSN_3(ALU, DIV, K), \ | |
1222 | INSN_3(ALU, MOD, K), \ | |
5e581dad DB |
1223 | /* 64 bit ALU operations. */ \ |
1224 | /* Register based. */ \ | |
1225 | INSN_3(ALU64, ADD, X), \ | |
1226 | INSN_3(ALU64, SUB, X), \ | |
1227 | INSN_3(ALU64, AND, X), \ | |
1228 | INSN_3(ALU64, OR, X), \ | |
1229 | INSN_3(ALU64, LSH, X), \ | |
1230 | INSN_3(ALU64, RSH, X), \ | |
1231 | INSN_3(ALU64, XOR, X), \ | |
1232 | INSN_3(ALU64, MUL, X), \ | |
1233 | INSN_3(ALU64, MOV, X), \ | |
1234 | INSN_3(ALU64, ARSH, X), \ | |
1235 | INSN_3(ALU64, DIV, X), \ | |
1236 | INSN_3(ALU64, MOD, X), \ | |
1237 | INSN_2(ALU64, NEG), \ | |
1238 | /* Immediate based. */ \ | |
1239 | INSN_3(ALU64, ADD, K), \ | |
1240 | INSN_3(ALU64, SUB, K), \ | |
1241 | INSN_3(ALU64, AND, K), \ | |
1242 | INSN_3(ALU64, OR, K), \ | |
1243 | INSN_3(ALU64, LSH, K), \ | |
1244 | INSN_3(ALU64, RSH, K), \ | |
1245 | INSN_3(ALU64, XOR, K), \ | |
1246 | INSN_3(ALU64, MUL, K), \ | |
1247 | INSN_3(ALU64, MOV, K), \ | |
1248 | INSN_3(ALU64, ARSH, K), \ | |
1249 | INSN_3(ALU64, DIV, K), \ | |
1250 | INSN_3(ALU64, MOD, K), \ | |
1251 | /* Call instruction. */ \ | |
1252 | INSN_2(JMP, CALL), \ | |
1253 | /* Exit instruction. */ \ | |
1254 | INSN_2(JMP, EXIT), \ | |
503a8865 JW |
1255 | /* 32-bit Jump instructions. */ \ |
1256 | /* Register based. */ \ | |
1257 | INSN_3(JMP32, JEQ, X), \ | |
1258 | INSN_3(JMP32, JNE, X), \ | |
1259 | INSN_3(JMP32, JGT, X), \ | |
1260 | INSN_3(JMP32, JLT, X), \ | |
1261 | INSN_3(JMP32, JGE, X), \ | |
1262 | INSN_3(JMP32, JLE, X), \ | |
1263 | INSN_3(JMP32, JSGT, X), \ | |
1264 | INSN_3(JMP32, JSLT, X), \ | |
1265 | INSN_3(JMP32, JSGE, X), \ | |
1266 | INSN_3(JMP32, JSLE, X), \ | |
1267 | INSN_3(JMP32, JSET, X), \ | |
1268 | /* Immediate based. */ \ | |
1269 | INSN_3(JMP32, JEQ, K), \ | |
1270 | INSN_3(JMP32, JNE, K), \ | |
1271 | INSN_3(JMP32, JGT, K), \ | |
1272 | INSN_3(JMP32, JLT, K), \ | |
1273 | INSN_3(JMP32, JGE, K), \ | |
1274 | INSN_3(JMP32, JLE, K), \ | |
1275 | INSN_3(JMP32, JSGT, K), \ | |
1276 | INSN_3(JMP32, JSLT, K), \ | |
1277 | INSN_3(JMP32, JSGE, K), \ | |
1278 | INSN_3(JMP32, JSLE, K), \ | |
1279 | INSN_3(JMP32, JSET, K), \ | |
5e581dad DB |
1280 | /* Jump instructions. */ \ |
1281 | /* Register based. */ \ | |
1282 | INSN_3(JMP, JEQ, X), \ | |
1283 | INSN_3(JMP, JNE, X), \ | |
1284 | INSN_3(JMP, JGT, X), \ | |
1285 | INSN_3(JMP, JLT, X), \ | |
1286 | INSN_3(JMP, JGE, X), \ | |
1287 | INSN_3(JMP, JLE, X), \ | |
1288 | INSN_3(JMP, JSGT, X), \ | |
1289 | INSN_3(JMP, JSLT, X), \ | |
1290 | INSN_3(JMP, JSGE, X), \ | |
1291 | INSN_3(JMP, JSLE, X), \ | |
1292 | INSN_3(JMP, JSET, X), \ | |
1293 | /* Immediate based. */ \ | |
1294 | INSN_3(JMP, JEQ, K), \ | |
1295 | INSN_3(JMP, JNE, K), \ | |
1296 | INSN_3(JMP, JGT, K), \ | |
1297 | INSN_3(JMP, JLT, K), \ | |
1298 | INSN_3(JMP, JGE, K), \ | |
1299 | INSN_3(JMP, JLE, K), \ | |
1300 | INSN_3(JMP, JSGT, K), \ | |
1301 | INSN_3(JMP, JSLT, K), \ | |
1302 | INSN_3(JMP, JSGE, K), \ | |
1303 | INSN_3(JMP, JSLE, K), \ | |
1304 | INSN_3(JMP, JSET, K), \ | |
1305 | INSN_2(JMP, JA), \ | |
1306 | /* Store instructions. */ \ | |
1307 | /* Register based. */ \ | |
1308 | INSN_3(STX, MEM, B), \ | |
1309 | INSN_3(STX, MEM, H), \ | |
1310 | INSN_3(STX, MEM, W), \ | |
1311 | INSN_3(STX, MEM, DW), \ | |
1312 | INSN_3(STX, XADD, W), \ | |
1313 | INSN_3(STX, XADD, DW), \ | |
1314 | /* Immediate based. */ \ | |
1315 | INSN_3(ST, MEM, B), \ | |
1316 | INSN_3(ST, MEM, H), \ | |
1317 | INSN_3(ST, MEM, W), \ | |
1318 | INSN_3(ST, MEM, DW), \ | |
1319 | /* Load instructions. */ \ | |
1320 | /* Register based. */ \ | |
1321 | INSN_3(LDX, MEM, B), \ | |
1322 | INSN_3(LDX, MEM, H), \ | |
1323 | INSN_3(LDX, MEM, W), \ | |
1324 | INSN_3(LDX, MEM, DW), \ | |
1325 | /* Immediate based. */ \ | |
e0cea7ce | 1326 | INSN_3(LD, IMM, DW) |
5e581dad DB |
1327 | |
1328 | bool bpf_opcode_in_insntable(u8 code) | |
1329 | { | |
1330 | #define BPF_INSN_2_TBL(x, y) [BPF_##x | BPF_##y] = true | |
1331 | #define BPF_INSN_3_TBL(x, y, z) [BPF_##x | BPF_##y | BPF_##z] = true | |
1332 | static const bool public_insntable[256] = { | |
1333 | [0 ... 255] = false, | |
1334 | /* Now overwrite non-defaults ... */ | |
1335 | BPF_INSN_MAP(BPF_INSN_2_TBL, BPF_INSN_3_TBL), | |
e0cea7ce DB |
1336 | /* UAPI exposed, but rewritten opcodes. cBPF carry-over. */ |
1337 | [BPF_LD | BPF_ABS | BPF_B] = true, | |
1338 | [BPF_LD | BPF_ABS | BPF_H] = true, | |
1339 | [BPF_LD | BPF_ABS | BPF_W] = true, | |
1340 | [BPF_LD | BPF_IND | BPF_B] = true, | |
1341 | [BPF_LD | BPF_IND | BPF_H] = true, | |
1342 | [BPF_LD | BPF_IND | BPF_W] = true, | |
5e581dad DB |
1343 | }; |
1344 | #undef BPF_INSN_3_TBL | |
1345 | #undef BPF_INSN_2_TBL | |
1346 | return public_insntable[code]; | |
1347 | } | |
1348 | ||
290af866 | 1349 | #ifndef CONFIG_BPF_JIT_ALWAYS_ON |
6e07a634 | 1350 | u64 __weak bpf_probe_read_kernel(void *dst, u32 size, const void *unsafe_ptr) |
2a02759e AS |
1351 | { |
1352 | memset(dst, 0, size); | |
1353 | return -EFAULT; | |
1354 | } | |
6e07a634 | 1355 | |
f5bffecd | 1356 | /** |
7ae457c1 | 1357 | * __bpf_prog_run - run eBPF program on a given context |
de1da68d | 1358 | * @regs: is the array of MAX_BPF_EXT_REG eBPF pseudo-registers |
7ae457c1 | 1359 | * @insn: is the array of eBPF instructions |
de1da68d | 1360 | * @stack: is the eBPF storage stack |
f5bffecd | 1361 | * |
7ae457c1 | 1362 | * Decode and execute eBPF instructions. |
f5bffecd | 1363 | */ |
080b6f40 | 1364 | static u64 ___bpf_prog_run(u64 *regs, const struct bpf_insn *insn, u64 *stack) |
f5bffecd | 1365 | { |
5e581dad DB |
1366 | #define BPF_INSN_2_LBL(x, y) [BPF_##x | BPF_##y] = &&x##_##y |
1367 | #define BPF_INSN_3_LBL(x, y, z) [BPF_##x | BPF_##y | BPF_##z] = &&x##_##y##_##z | |
e55a7325 | 1368 | static const void * const jumptable[256] __annotate_jump_table = { |
f5bffecd AS |
1369 | [0 ... 255] = &&default_label, |
1370 | /* Now overwrite non-defaults ... */ | |
5e581dad DB |
1371 | BPF_INSN_MAP(BPF_INSN_2_LBL, BPF_INSN_3_LBL), |
1372 | /* Non-UAPI available opcodes. */ | |
1ea47e01 | 1373 | [BPF_JMP | BPF_CALL_ARGS] = &&JMP_CALL_ARGS, |
71189fa9 | 1374 | [BPF_JMP | BPF_TAIL_CALL] = &&JMP_TAIL_CALL, |
2a02759e AS |
1375 | [BPF_LDX | BPF_PROBE_MEM | BPF_B] = &&LDX_PROBE_MEM_B, |
1376 | [BPF_LDX | BPF_PROBE_MEM | BPF_H] = &&LDX_PROBE_MEM_H, | |
1377 | [BPF_LDX | BPF_PROBE_MEM | BPF_W] = &&LDX_PROBE_MEM_W, | |
1378 | [BPF_LDX | BPF_PROBE_MEM | BPF_DW] = &&LDX_PROBE_MEM_DW, | |
f5bffecd | 1379 | }; |
5e581dad DB |
1380 | #undef BPF_INSN_3_LBL |
1381 | #undef BPF_INSN_2_LBL | |
04fd61ab | 1382 | u32 tail_call_cnt = 0; |
f5bffecd AS |
1383 | |
1384 | #define CONT ({ insn++; goto select_insn; }) | |
1385 | #define CONT_JMP ({ insn++; goto select_insn; }) | |
1386 | ||
f5bffecd AS |
1387 | select_insn: |
1388 | goto *jumptable[insn->code]; | |
1389 | ||
1390 | /* ALU */ | |
1391 | #define ALU(OPCODE, OP) \ | |
1392 | ALU64_##OPCODE##_X: \ | |
1393 | DST = DST OP SRC; \ | |
1394 | CONT; \ | |
1395 | ALU_##OPCODE##_X: \ | |
1396 | DST = (u32) DST OP (u32) SRC; \ | |
1397 | CONT; \ | |
1398 | ALU64_##OPCODE##_K: \ | |
1399 | DST = DST OP IMM; \ | |
1400 | CONT; \ | |
1401 | ALU_##OPCODE##_K: \ | |
1402 | DST = (u32) DST OP (u32) IMM; \ | |
1403 | CONT; | |
1404 | ||
1405 | ALU(ADD, +) | |
1406 | ALU(SUB, -) | |
1407 | ALU(AND, &) | |
1408 | ALU(OR, |) | |
1409 | ALU(LSH, <<) | |
1410 | ALU(RSH, >>) | |
1411 | ALU(XOR, ^) | |
1412 | ALU(MUL, *) | |
1413 | #undef ALU | |
1414 | ALU_NEG: | |
1415 | DST = (u32) -DST; | |
1416 | CONT; | |
1417 | ALU64_NEG: | |
1418 | DST = -DST; | |
1419 | CONT; | |
1420 | ALU_MOV_X: | |
1421 | DST = (u32) SRC; | |
1422 | CONT; | |
1423 | ALU_MOV_K: | |
1424 | DST = (u32) IMM; | |
1425 | CONT; | |
1426 | ALU64_MOV_X: | |
1427 | DST = SRC; | |
1428 | CONT; | |
1429 | ALU64_MOV_K: | |
1430 | DST = IMM; | |
1431 | CONT; | |
02ab695b AS |
1432 | LD_IMM_DW: |
1433 | DST = (u64) (u32) insn[0].imm | ((u64) (u32) insn[1].imm) << 32; | |
1434 | insn++; | |
1435 | CONT; | |
2dc6b100 | 1436 | ALU_ARSH_X: |
75672dda | 1437 | DST = (u64) (u32) (((s32) DST) >> SRC); |
2dc6b100 JW |
1438 | CONT; |
1439 | ALU_ARSH_K: | |
75672dda | 1440 | DST = (u64) (u32) (((s32) DST) >> IMM); |
2dc6b100 | 1441 | CONT; |
f5bffecd AS |
1442 | ALU64_ARSH_X: |
1443 | (*(s64 *) &DST) >>= SRC; | |
1444 | CONT; | |
1445 | ALU64_ARSH_K: | |
1446 | (*(s64 *) &DST) >>= IMM; | |
1447 | CONT; | |
1448 | ALU64_MOD_X: | |
144cd91c DB |
1449 | div64_u64_rem(DST, SRC, &AX); |
1450 | DST = AX; | |
f5bffecd AS |
1451 | CONT; |
1452 | ALU_MOD_X: | |
144cd91c DB |
1453 | AX = (u32) DST; |
1454 | DST = do_div(AX, (u32) SRC); | |
f5bffecd AS |
1455 | CONT; |
1456 | ALU64_MOD_K: | |
144cd91c DB |
1457 | div64_u64_rem(DST, IMM, &AX); |
1458 | DST = AX; | |
f5bffecd AS |
1459 | CONT; |
1460 | ALU_MOD_K: | |
144cd91c DB |
1461 | AX = (u32) DST; |
1462 | DST = do_div(AX, (u32) IMM); | |
f5bffecd AS |
1463 | CONT; |
1464 | ALU64_DIV_X: | |
876a7ae6 | 1465 | DST = div64_u64(DST, SRC); |
f5bffecd AS |
1466 | CONT; |
1467 | ALU_DIV_X: | |
144cd91c DB |
1468 | AX = (u32) DST; |
1469 | do_div(AX, (u32) SRC); | |
1470 | DST = (u32) AX; | |
f5bffecd AS |
1471 | CONT; |
1472 | ALU64_DIV_K: | |
876a7ae6 | 1473 | DST = div64_u64(DST, IMM); |
f5bffecd AS |
1474 | CONT; |
1475 | ALU_DIV_K: | |
144cd91c DB |
1476 | AX = (u32) DST; |
1477 | do_div(AX, (u32) IMM); | |
1478 | DST = (u32) AX; | |
f5bffecd AS |
1479 | CONT; |
1480 | ALU_END_TO_BE: | |
1481 | switch (IMM) { | |
1482 | case 16: | |
1483 | DST = (__force u16) cpu_to_be16(DST); | |
1484 | break; | |
1485 | case 32: | |
1486 | DST = (__force u32) cpu_to_be32(DST); | |
1487 | break; | |
1488 | case 64: | |
1489 | DST = (__force u64) cpu_to_be64(DST); | |
1490 | break; | |
1491 | } | |
1492 | CONT; | |
1493 | ALU_END_TO_LE: | |
1494 | switch (IMM) { | |
1495 | case 16: | |
1496 | DST = (__force u16) cpu_to_le16(DST); | |
1497 | break; | |
1498 | case 32: | |
1499 | DST = (__force u32) cpu_to_le32(DST); | |
1500 | break; | |
1501 | case 64: | |
1502 | DST = (__force u64) cpu_to_le64(DST); | |
1503 | break; | |
1504 | } | |
1505 | CONT; | |
1506 | ||
1507 | /* CALL */ | |
1508 | JMP_CALL: | |
1509 | /* Function call scratches BPF_R1-BPF_R5 registers, | |
1510 | * preserves BPF_R6-BPF_R9, and stores return value | |
1511 | * into BPF_R0. | |
1512 | */ | |
1513 | BPF_R0 = (__bpf_call_base + insn->imm)(BPF_R1, BPF_R2, BPF_R3, | |
1514 | BPF_R4, BPF_R5); | |
1515 | CONT; | |
1516 | ||
1ea47e01 AS |
1517 | JMP_CALL_ARGS: |
1518 | BPF_R0 = (__bpf_call_base_args + insn->imm)(BPF_R1, BPF_R2, | |
1519 | BPF_R3, BPF_R4, | |
1520 | BPF_R5, | |
1521 | insn + insn->off + 1); | |
1522 | CONT; | |
1523 | ||
04fd61ab AS |
1524 | JMP_TAIL_CALL: { |
1525 | struct bpf_map *map = (struct bpf_map *) (unsigned long) BPF_R2; | |
1526 | struct bpf_array *array = container_of(map, struct bpf_array, map); | |
1527 | struct bpf_prog *prog; | |
90caccdd | 1528 | u32 index = BPF_R3; |
04fd61ab AS |
1529 | |
1530 | if (unlikely(index >= array->map.max_entries)) | |
1531 | goto out; | |
04fd61ab AS |
1532 | if (unlikely(tail_call_cnt > MAX_TAIL_CALL_CNT)) |
1533 | goto out; | |
1534 | ||
1535 | tail_call_cnt++; | |
1536 | ||
2a36f0b9 | 1537 | prog = READ_ONCE(array->ptrs[index]); |
1ca1cc98 | 1538 | if (!prog) |
04fd61ab AS |
1539 | goto out; |
1540 | ||
c4675f93 DB |
1541 | /* ARG1 at this point is guaranteed to point to CTX from |
1542 | * the verifier side due to the fact that the tail call is | |
0142dddc | 1543 | * handled like a helper, that is, bpf_tail_call_proto, |
c4675f93 DB |
1544 | * where arg1_type is ARG_PTR_TO_CTX. |
1545 | */ | |
04fd61ab AS |
1546 | insn = prog->insnsi; |
1547 | goto select_insn; | |
1548 | out: | |
1549 | CONT; | |
1550 | } | |
f5bffecd AS |
1551 | JMP_JA: |
1552 | insn += insn->off; | |
1553 | CONT; | |
f5bffecd AS |
1554 | JMP_EXIT: |
1555 | return BPF_R0; | |
503a8865 JW |
1556 | /* JMP */ |
1557 | #define COND_JMP(SIGN, OPCODE, CMP_OP) \ | |
1558 | JMP_##OPCODE##_X: \ | |
1559 | if ((SIGN##64) DST CMP_OP (SIGN##64) SRC) { \ | |
1560 | insn += insn->off; \ | |
1561 | CONT_JMP; \ | |
1562 | } \ | |
1563 | CONT; \ | |
1564 | JMP32_##OPCODE##_X: \ | |
1565 | if ((SIGN##32) DST CMP_OP (SIGN##32) SRC) { \ | |
1566 | insn += insn->off; \ | |
1567 | CONT_JMP; \ | |
1568 | } \ | |
1569 | CONT; \ | |
1570 | JMP_##OPCODE##_K: \ | |
1571 | if ((SIGN##64) DST CMP_OP (SIGN##64) IMM) { \ | |
1572 | insn += insn->off; \ | |
1573 | CONT_JMP; \ | |
1574 | } \ | |
1575 | CONT; \ | |
1576 | JMP32_##OPCODE##_K: \ | |
1577 | if ((SIGN##32) DST CMP_OP (SIGN##32) IMM) { \ | |
1578 | insn += insn->off; \ | |
1579 | CONT_JMP; \ | |
1580 | } \ | |
1581 | CONT; | |
1582 | COND_JMP(u, JEQ, ==) | |
1583 | COND_JMP(u, JNE, !=) | |
1584 | COND_JMP(u, JGT, >) | |
1585 | COND_JMP(u, JLT, <) | |
1586 | COND_JMP(u, JGE, >=) | |
1587 | COND_JMP(u, JLE, <=) | |
1588 | COND_JMP(u, JSET, &) | |
1589 | COND_JMP(s, JSGT, >) | |
1590 | COND_JMP(s, JSLT, <) | |
1591 | COND_JMP(s, JSGE, >=) | |
1592 | COND_JMP(s, JSLE, <=) | |
1593 | #undef COND_JMP | |
f5bffecd AS |
1594 | /* STX and ST and LDX*/ |
1595 | #define LDST(SIZEOP, SIZE) \ | |
1596 | STX_MEM_##SIZEOP: \ | |
1597 | *(SIZE *)(unsigned long) (DST + insn->off) = SRC; \ | |
1598 | CONT; \ | |
1599 | ST_MEM_##SIZEOP: \ | |
1600 | *(SIZE *)(unsigned long) (DST + insn->off) = IMM; \ | |
1601 | CONT; \ | |
1602 | LDX_MEM_##SIZEOP: \ | |
1603 | DST = *(SIZE *)(unsigned long) (SRC + insn->off); \ | |
1604 | CONT; | |
1605 | ||
1606 | LDST(B, u8) | |
1607 | LDST(H, u16) | |
1608 | LDST(W, u32) | |
1609 | LDST(DW, u64) | |
1610 | #undef LDST | |
6e07a634 DB |
1611 | #define LDX_PROBE(SIZEOP, SIZE) \ |
1612 | LDX_PROBE_MEM_##SIZEOP: \ | |
85d31dd0 | 1613 | bpf_probe_read_kernel(&DST, SIZE, (const void *)(long) (SRC + insn->off)); \ |
2a02759e AS |
1614 | CONT; |
1615 | LDX_PROBE(B, 1) | |
1616 | LDX_PROBE(H, 2) | |
1617 | LDX_PROBE(W, 4) | |
1618 | LDX_PROBE(DW, 8) | |
1619 | #undef LDX_PROBE | |
1620 | ||
f5bffecd AS |
1621 | STX_XADD_W: /* lock xadd *(u32 *)(dst_reg + off16) += src_reg */ |
1622 | atomic_add((u32) SRC, (atomic_t *)(unsigned long) | |
1623 | (DST + insn->off)); | |
1624 | CONT; | |
1625 | STX_XADD_DW: /* lock xadd *(u64 *)(dst_reg + off16) += src_reg */ | |
1626 | atomic64_add((u64) SRC, (atomic64_t *)(unsigned long) | |
1627 | (DST + insn->off)); | |
1628 | CONT; | |
f5bffecd AS |
1629 | |
1630 | default_label: | |
5e581dad DB |
1631 | /* If we ever reach this, we have a bug somewhere. Die hard here |
1632 | * instead of just returning 0; we could be somewhere in a subprog, | |
1633 | * so execution could continue otherwise which we do /not/ want. | |
1634 | * | |
1635 | * Note, verifier whitelists all opcodes in bpf_opcode_in_insntable(). | |
1636 | */ | |
1637 | pr_warn("BPF interpreter: unknown opcode %02x\n", insn->code); | |
1638 | BUG_ON(1); | |
f5bffecd AS |
1639 | return 0; |
1640 | } | |
f696b8f4 | 1641 | |
b870aa90 AS |
1642 | #define PROG_NAME(stack_size) __bpf_prog_run##stack_size |
1643 | #define DEFINE_BPF_PROG_RUN(stack_size) \ | |
1644 | static unsigned int PROG_NAME(stack_size)(const void *ctx, const struct bpf_insn *insn) \ | |
1645 | { \ | |
1646 | u64 stack[stack_size / sizeof(u64)]; \ | |
144cd91c | 1647 | u64 regs[MAX_BPF_EXT_REG]; \ |
b870aa90 AS |
1648 | \ |
1649 | FP = (u64) (unsigned long) &stack[ARRAY_SIZE(stack)]; \ | |
1650 | ARG1 = (u64) (unsigned long) ctx; \ | |
1651 | return ___bpf_prog_run(regs, insn, stack); \ | |
f696b8f4 | 1652 | } |
f5bffecd | 1653 | |
1ea47e01 AS |
1654 | #define PROG_NAME_ARGS(stack_size) __bpf_prog_run_args##stack_size |
1655 | #define DEFINE_BPF_PROG_RUN_ARGS(stack_size) \ | |
1656 | static u64 PROG_NAME_ARGS(stack_size)(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5, \ | |
1657 | const struct bpf_insn *insn) \ | |
1658 | { \ | |
1659 | u64 stack[stack_size / sizeof(u64)]; \ | |
144cd91c | 1660 | u64 regs[MAX_BPF_EXT_REG]; \ |
1ea47e01 AS |
1661 | \ |
1662 | FP = (u64) (unsigned long) &stack[ARRAY_SIZE(stack)]; \ | |
1663 | BPF_R1 = r1; \ | |
1664 | BPF_R2 = r2; \ | |
1665 | BPF_R3 = r3; \ | |
1666 | BPF_R4 = r4; \ | |
1667 | BPF_R5 = r5; \ | |
1668 | return ___bpf_prog_run(regs, insn, stack); \ | |
1669 | } | |
1670 | ||
b870aa90 AS |
1671 | #define EVAL1(FN, X) FN(X) |
1672 | #define EVAL2(FN, X, Y...) FN(X) EVAL1(FN, Y) | |
1673 | #define EVAL3(FN, X, Y...) FN(X) EVAL2(FN, Y) | |
1674 | #define EVAL4(FN, X, Y...) FN(X) EVAL3(FN, Y) | |
1675 | #define EVAL5(FN, X, Y...) FN(X) EVAL4(FN, Y) | |
1676 | #define EVAL6(FN, X, Y...) FN(X) EVAL5(FN, Y) | |
1677 | ||
1678 | EVAL6(DEFINE_BPF_PROG_RUN, 32, 64, 96, 128, 160, 192); | |
1679 | EVAL6(DEFINE_BPF_PROG_RUN, 224, 256, 288, 320, 352, 384); | |
1680 | EVAL4(DEFINE_BPF_PROG_RUN, 416, 448, 480, 512); | |
1681 | ||
1ea47e01 AS |
1682 | EVAL6(DEFINE_BPF_PROG_RUN_ARGS, 32, 64, 96, 128, 160, 192); |
1683 | EVAL6(DEFINE_BPF_PROG_RUN_ARGS, 224, 256, 288, 320, 352, 384); | |
1684 | EVAL4(DEFINE_BPF_PROG_RUN_ARGS, 416, 448, 480, 512); | |
1685 | ||
b870aa90 AS |
1686 | #define PROG_NAME_LIST(stack_size) PROG_NAME(stack_size), |
1687 | ||
1688 | static unsigned int (*interpreters[])(const void *ctx, | |
1689 | const struct bpf_insn *insn) = { | |
1690 | EVAL6(PROG_NAME_LIST, 32, 64, 96, 128, 160, 192) | |
1691 | EVAL6(PROG_NAME_LIST, 224, 256, 288, 320, 352, 384) | |
1692 | EVAL4(PROG_NAME_LIST, 416, 448, 480, 512) | |
1693 | }; | |
1ea47e01 AS |
1694 | #undef PROG_NAME_LIST |
1695 | #define PROG_NAME_LIST(stack_size) PROG_NAME_ARGS(stack_size), | |
1696 | static u64 (*interpreters_args[])(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5, | |
1697 | const struct bpf_insn *insn) = { | |
1698 | EVAL6(PROG_NAME_LIST, 32, 64, 96, 128, 160, 192) | |
1699 | EVAL6(PROG_NAME_LIST, 224, 256, 288, 320, 352, 384) | |
1700 | EVAL4(PROG_NAME_LIST, 416, 448, 480, 512) | |
1701 | }; | |
1702 | #undef PROG_NAME_LIST | |
1703 | ||
1704 | void bpf_patch_call_args(struct bpf_insn *insn, u32 stack_depth) | |
1705 | { | |
1706 | stack_depth = max_t(u32, stack_depth, 1); | |
1707 | insn->off = (s16) insn->imm; | |
1708 | insn->imm = interpreters_args[(round_up(stack_depth, 32) / 32) - 1] - | |
1709 | __bpf_call_base_args; | |
1710 | insn->code = BPF_JMP | BPF_CALL_ARGS; | |
1711 | } | |
b870aa90 | 1712 | |
290af866 | 1713 | #else |
fa9dd599 DB |
1714 | static unsigned int __bpf_prog_ret0_warn(const void *ctx, |
1715 | const struct bpf_insn *insn) | |
290af866 | 1716 | { |
fa9dd599 DB |
1717 | /* If this handler ever gets executed, then BPF_JIT_ALWAYS_ON |
1718 | * is not working properly, so warn about it! | |
1719 | */ | |
1720 | WARN_ON_ONCE(1); | |
290af866 AS |
1721 | return 0; |
1722 | } | |
1723 | #endif | |
1724 | ||
3324b584 DB |
1725 | bool bpf_prog_array_compatible(struct bpf_array *array, |
1726 | const struct bpf_prog *fp) | |
04fd61ab | 1727 | { |
9802d865 JB |
1728 | if (fp->kprobe_override) |
1729 | return false; | |
1730 | ||
2beee5f5 | 1731 | if (!array->aux->type) { |
3324b584 DB |
1732 | /* There's no owner yet where we could check for |
1733 | * compatibility. | |
1734 | */ | |
2beee5f5 DB |
1735 | array->aux->type = fp->type; |
1736 | array->aux->jited = fp->jited; | |
3324b584 | 1737 | return true; |
04fd61ab | 1738 | } |
3324b584 | 1739 | |
2beee5f5 DB |
1740 | return array->aux->type == fp->type && |
1741 | array->aux->jited == fp->jited; | |
04fd61ab AS |
1742 | } |
1743 | ||
3324b584 | 1744 | static int bpf_check_tail_call(const struct bpf_prog *fp) |
04fd61ab AS |
1745 | { |
1746 | struct bpf_prog_aux *aux = fp->aux; | |
984fe94f | 1747 | int i, ret = 0; |
04fd61ab | 1748 | |
984fe94f | 1749 | mutex_lock(&aux->used_maps_mutex); |
04fd61ab | 1750 | for (i = 0; i < aux->used_map_cnt; i++) { |
3324b584 | 1751 | struct bpf_map *map = aux->used_maps[i]; |
04fd61ab | 1752 | struct bpf_array *array; |
04fd61ab | 1753 | |
04fd61ab AS |
1754 | if (map->map_type != BPF_MAP_TYPE_PROG_ARRAY) |
1755 | continue; | |
3324b584 | 1756 | |
04fd61ab | 1757 | array = container_of(map, struct bpf_array, map); |
984fe94f YZ |
1758 | if (!bpf_prog_array_compatible(array, fp)) { |
1759 | ret = -EINVAL; | |
1760 | goto out; | |
1761 | } | |
04fd61ab AS |
1762 | } |
1763 | ||
984fe94f YZ |
1764 | out: |
1765 | mutex_unlock(&aux->used_maps_mutex); | |
1766 | return ret; | |
04fd61ab AS |
1767 | } |
1768 | ||
9facc336 DB |
1769 | static void bpf_prog_select_func(struct bpf_prog *fp) |
1770 | { | |
1771 | #ifndef CONFIG_BPF_JIT_ALWAYS_ON | |
1772 | u32 stack_depth = max_t(u32, fp->aux->stack_depth, 1); | |
1773 | ||
1774 | fp->bpf_func = interpreters[(round_up(stack_depth, 32) / 32) - 1]; | |
1775 | #else | |
1776 | fp->bpf_func = __bpf_prog_ret0_warn; | |
1777 | #endif | |
1778 | } | |
1779 | ||
f5bffecd | 1780 | /** |
3324b584 | 1781 | * bpf_prog_select_runtime - select exec runtime for BPF program |
7ae457c1 | 1782 | * @fp: bpf_prog populated with internal BPF program |
d1c55ab5 | 1783 | * @err: pointer to error variable |
f5bffecd | 1784 | * |
3324b584 DB |
1785 | * Try to JIT eBPF program, if JIT is not available, use interpreter. |
1786 | * The BPF program will be executed via BPF_PROG_RUN() macro. | |
f5bffecd | 1787 | */ |
d1c55ab5 | 1788 | struct bpf_prog *bpf_prog_select_runtime(struct bpf_prog *fp, int *err) |
f5bffecd | 1789 | { |
9facc336 DB |
1790 | /* In case of BPF to BPF calls, verifier did all the prep |
1791 | * work with regards to JITing, etc. | |
1792 | */ | |
1793 | if (fp->bpf_func) | |
1794 | goto finalize; | |
8007e40a | 1795 | |
9facc336 | 1796 | bpf_prog_select_func(fp); |
f5bffecd | 1797 | |
d1c55ab5 DB |
1798 | /* eBPF JITs can rewrite the program in case constant |
1799 | * blinding is active. However, in case of error during | |
1800 | * blinding, bpf_int_jit_compile() must always return a | |
1801 | * valid program, which in this case would simply not | |
1802 | * be JITed, but falls back to the interpreter. | |
1803 | */ | |
ab3f0063 | 1804 | if (!bpf_prog_is_dev_bound(fp->aux)) { |
c454a46b MKL |
1805 | *err = bpf_prog_alloc_jited_linfo(fp); |
1806 | if (*err) | |
1807 | return fp; | |
1808 | ||
ab3f0063 | 1809 | fp = bpf_int_jit_compile(fp); |
290af866 | 1810 | if (!fp->jited) { |
c454a46b MKL |
1811 | bpf_prog_free_jited_linfo(fp); |
1812 | #ifdef CONFIG_BPF_JIT_ALWAYS_ON | |
290af866 AS |
1813 | *err = -ENOTSUPP; |
1814 | return fp; | |
290af866 | 1815 | #endif |
c454a46b MKL |
1816 | } else { |
1817 | bpf_prog_free_unused_jited_linfo(fp); | |
1818 | } | |
ab3f0063 JK |
1819 | } else { |
1820 | *err = bpf_prog_offload_compile(fp); | |
1821 | if (*err) | |
1822 | return fp; | |
1823 | } | |
9facc336 DB |
1824 | |
1825 | finalize: | |
60a3b225 | 1826 | bpf_prog_lock_ro(fp); |
04fd61ab | 1827 | |
3324b584 DB |
1828 | /* The tail call compatibility check can only be done at |
1829 | * this late stage as we need to determine, if we deal | |
1830 | * with JITed or non JITed program concatenations and not | |
1831 | * all eBPF JITs might immediately support all features. | |
1832 | */ | |
d1c55ab5 | 1833 | *err = bpf_check_tail_call(fp); |
85782e03 | 1834 | |
d1c55ab5 | 1835 | return fp; |
f5bffecd | 1836 | } |
7ae457c1 | 1837 | EXPORT_SYMBOL_GPL(bpf_prog_select_runtime); |
f5bffecd | 1838 | |
e87c6bc3 YS |
1839 | static unsigned int __bpf_prog_ret1(const void *ctx, |
1840 | const struct bpf_insn *insn) | |
1841 | { | |
1842 | return 1; | |
1843 | } | |
1844 | ||
1845 | static struct bpf_prog_dummy { | |
1846 | struct bpf_prog prog; | |
1847 | } dummy_bpf_prog = { | |
1848 | .prog = { | |
1849 | .bpf_func = __bpf_prog_ret1, | |
1850 | }, | |
1851 | }; | |
1852 | ||
324bda9e AS |
1853 | /* to avoid allocating empty bpf_prog_array for cgroups that |
1854 | * don't have bpf program attached use one global 'empty_prog_array' | |
1855 | * It will not be modified the caller of bpf_prog_array_alloc() | |
1856 | * (since caller requested prog_cnt == 0) | |
1857 | * that pointer should be 'freed' by bpf_prog_array_free() | |
1858 | */ | |
1859 | static struct { | |
1860 | struct bpf_prog_array hdr; | |
1861 | struct bpf_prog *null_prog; | |
1862 | } empty_prog_array = { | |
1863 | .null_prog = NULL, | |
1864 | }; | |
1865 | ||
d29ab6e1 | 1866 | struct bpf_prog_array *bpf_prog_array_alloc(u32 prog_cnt, gfp_t flags) |
324bda9e AS |
1867 | { |
1868 | if (prog_cnt) | |
1869 | return kzalloc(sizeof(struct bpf_prog_array) + | |
394e40a2 RG |
1870 | sizeof(struct bpf_prog_array_item) * |
1871 | (prog_cnt + 1), | |
324bda9e AS |
1872 | flags); |
1873 | ||
1874 | return &empty_prog_array.hdr; | |
1875 | } | |
1876 | ||
54e9c9d4 | 1877 | void bpf_prog_array_free(struct bpf_prog_array *progs) |
324bda9e | 1878 | { |
54e9c9d4 | 1879 | if (!progs || progs == &empty_prog_array.hdr) |
324bda9e AS |
1880 | return; |
1881 | kfree_rcu(progs, rcu); | |
1882 | } | |
1883 | ||
54e9c9d4 | 1884 | int bpf_prog_array_length(struct bpf_prog_array *array) |
468e2f64 | 1885 | { |
394e40a2 | 1886 | struct bpf_prog_array_item *item; |
468e2f64 AS |
1887 | u32 cnt = 0; |
1888 | ||
54e9c9d4 | 1889 | for (item = array->items; item->prog; item++) |
394e40a2 | 1890 | if (item->prog != &dummy_bpf_prog.prog) |
c8c088ba | 1891 | cnt++; |
468e2f64 AS |
1892 | return cnt; |
1893 | } | |
1894 | ||
0d01da6a SF |
1895 | bool bpf_prog_array_is_empty(struct bpf_prog_array *array) |
1896 | { | |
1897 | struct bpf_prog_array_item *item; | |
1898 | ||
1899 | for (item = array->items; item->prog; item++) | |
1900 | if (item->prog != &dummy_bpf_prog.prog) | |
1901 | return false; | |
1902 | return true; | |
1903 | } | |
394e40a2 | 1904 | |
54e9c9d4 | 1905 | static bool bpf_prog_array_copy_core(struct bpf_prog_array *array, |
3a38bb98 YS |
1906 | u32 *prog_ids, |
1907 | u32 request_cnt) | |
1908 | { | |
394e40a2 | 1909 | struct bpf_prog_array_item *item; |
3a38bb98 YS |
1910 | int i = 0; |
1911 | ||
54e9c9d4 | 1912 | for (item = array->items; item->prog; item++) { |
394e40a2 | 1913 | if (item->prog == &dummy_bpf_prog.prog) |
3a38bb98 | 1914 | continue; |
394e40a2 | 1915 | prog_ids[i] = item->prog->aux->id; |
3a38bb98 | 1916 | if (++i == request_cnt) { |
394e40a2 | 1917 | item++; |
3a38bb98 YS |
1918 | break; |
1919 | } | |
1920 | } | |
1921 | ||
394e40a2 | 1922 | return !!(item->prog); |
3a38bb98 YS |
1923 | } |
1924 | ||
54e9c9d4 | 1925 | int bpf_prog_array_copy_to_user(struct bpf_prog_array *array, |
468e2f64 AS |
1926 | __u32 __user *prog_ids, u32 cnt) |
1927 | { | |
0911287c | 1928 | unsigned long err = 0; |
0911287c | 1929 | bool nospc; |
3a38bb98 | 1930 | u32 *ids; |
0911287c AS |
1931 | |
1932 | /* users of this function are doing: | |
1933 | * cnt = bpf_prog_array_length(); | |
1934 | * if (cnt > 0) | |
1935 | * bpf_prog_array_copy_to_user(..., cnt); | |
54e9c9d4 | 1936 | * so below kcalloc doesn't need extra cnt > 0 check. |
0911287c | 1937 | */ |
9c481b90 | 1938 | ids = kcalloc(cnt, sizeof(u32), GFP_USER | __GFP_NOWARN); |
0911287c AS |
1939 | if (!ids) |
1940 | return -ENOMEM; | |
394e40a2 | 1941 | nospc = bpf_prog_array_copy_core(array, ids, cnt); |
0911287c AS |
1942 | err = copy_to_user(prog_ids, ids, cnt * sizeof(u32)); |
1943 | kfree(ids); | |
1944 | if (err) | |
1945 | return -EFAULT; | |
1946 | if (nospc) | |
468e2f64 AS |
1947 | return -ENOSPC; |
1948 | return 0; | |
1949 | } | |
1950 | ||
54e9c9d4 | 1951 | void bpf_prog_array_delete_safe(struct bpf_prog_array *array, |
e87c6bc3 YS |
1952 | struct bpf_prog *old_prog) |
1953 | { | |
54e9c9d4 | 1954 | struct bpf_prog_array_item *item; |
e87c6bc3 | 1955 | |
54e9c9d4 | 1956 | for (item = array->items; item->prog; item++) |
394e40a2 RG |
1957 | if (item->prog == old_prog) { |
1958 | WRITE_ONCE(item->prog, &dummy_bpf_prog.prog); | |
e87c6bc3 YS |
1959 | break; |
1960 | } | |
1961 | } | |
1962 | ||
ce3aa9cc JS |
1963 | /** |
1964 | * bpf_prog_array_delete_safe_at() - Replaces the program at the given | |
1965 | * index into the program array with | |
1966 | * a dummy no-op program. | |
1967 | * @array: a bpf_prog_array | |
1968 | * @index: the index of the program to replace | |
1969 | * | |
1970 | * Skips over dummy programs, by not counting them, when calculating | |
b8c1a309 | 1971 | * the position of the program to replace. |
ce3aa9cc JS |
1972 | * |
1973 | * Return: | |
1974 | * * 0 - Success | |
1975 | * * -EINVAL - Invalid index value. Must be a non-negative integer. | |
1976 | * * -ENOENT - Index out of range | |
1977 | */ | |
1978 | int bpf_prog_array_delete_safe_at(struct bpf_prog_array *array, int index) | |
1979 | { | |
1980 | return bpf_prog_array_update_at(array, index, &dummy_bpf_prog.prog); | |
1981 | } | |
1982 | ||
1983 | /** | |
1984 | * bpf_prog_array_update_at() - Updates the program at the given index | |
1985 | * into the program array. | |
1986 | * @array: a bpf_prog_array | |
1987 | * @index: the index of the program to update | |
1988 | * @prog: the program to insert into the array | |
1989 | * | |
1990 | * Skips over dummy programs, by not counting them, when calculating | |
1991 | * the position of the program to update. | |
1992 | * | |
1993 | * Return: | |
1994 | * * 0 - Success | |
1995 | * * -EINVAL - Invalid index value. Must be a non-negative integer. | |
1996 | * * -ENOENT - Index out of range | |
1997 | */ | |
1998 | int bpf_prog_array_update_at(struct bpf_prog_array *array, int index, | |
1999 | struct bpf_prog *prog) | |
2000 | { | |
2001 | struct bpf_prog_array_item *item; | |
2002 | ||
2003 | if (unlikely(index < 0)) | |
2004 | return -EINVAL; | |
2005 | ||
2006 | for (item = array->items; item->prog; item++) { | |
2007 | if (item->prog == &dummy_bpf_prog.prog) | |
2008 | continue; | |
2009 | if (!index) { | |
2010 | WRITE_ONCE(item->prog, prog); | |
2011 | return 0; | |
2012 | } | |
2013 | index--; | |
2014 | } | |
2015 | return -ENOENT; | |
2016 | } | |
2017 | ||
54e9c9d4 | 2018 | int bpf_prog_array_copy(struct bpf_prog_array *old_array, |
e87c6bc3 YS |
2019 | struct bpf_prog *exclude_prog, |
2020 | struct bpf_prog *include_prog, | |
2021 | struct bpf_prog_array **new_array) | |
2022 | { | |
2023 | int new_prog_cnt, carry_prog_cnt = 0; | |
394e40a2 | 2024 | struct bpf_prog_array_item *existing; |
e87c6bc3 | 2025 | struct bpf_prog_array *array; |
170a7e3e | 2026 | bool found_exclude = false; |
e87c6bc3 YS |
2027 | int new_prog_idx = 0; |
2028 | ||
2029 | /* Figure out how many existing progs we need to carry over to | |
2030 | * the new array. | |
2031 | */ | |
2032 | if (old_array) { | |
394e40a2 RG |
2033 | existing = old_array->items; |
2034 | for (; existing->prog; existing++) { | |
2035 | if (existing->prog == exclude_prog) { | |
170a7e3e SY |
2036 | found_exclude = true; |
2037 | continue; | |
2038 | } | |
394e40a2 | 2039 | if (existing->prog != &dummy_bpf_prog.prog) |
e87c6bc3 | 2040 | carry_prog_cnt++; |
394e40a2 | 2041 | if (existing->prog == include_prog) |
e87c6bc3 YS |
2042 | return -EEXIST; |
2043 | } | |
2044 | } | |
2045 | ||
170a7e3e SY |
2046 | if (exclude_prog && !found_exclude) |
2047 | return -ENOENT; | |
2048 | ||
e87c6bc3 YS |
2049 | /* How many progs (not NULL) will be in the new array? */ |
2050 | new_prog_cnt = carry_prog_cnt; | |
2051 | if (include_prog) | |
2052 | new_prog_cnt += 1; | |
2053 | ||
2054 | /* Do we have any prog (not NULL) in the new array? */ | |
2055 | if (!new_prog_cnt) { | |
2056 | *new_array = NULL; | |
2057 | return 0; | |
2058 | } | |
2059 | ||
2060 | /* +1 as the end of prog_array is marked with NULL */ | |
2061 | array = bpf_prog_array_alloc(new_prog_cnt + 1, GFP_KERNEL); | |
2062 | if (!array) | |
2063 | return -ENOMEM; | |
2064 | ||
2065 | /* Fill in the new prog array */ | |
2066 | if (carry_prog_cnt) { | |
394e40a2 RG |
2067 | existing = old_array->items; |
2068 | for (; existing->prog; existing++) | |
2069 | if (existing->prog != exclude_prog && | |
2070 | existing->prog != &dummy_bpf_prog.prog) { | |
2071 | array->items[new_prog_idx++].prog = | |
2072 | existing->prog; | |
2073 | } | |
e87c6bc3 YS |
2074 | } |
2075 | if (include_prog) | |
394e40a2 RG |
2076 | array->items[new_prog_idx++].prog = include_prog; |
2077 | array->items[new_prog_idx].prog = NULL; | |
e87c6bc3 YS |
2078 | *new_array = array; |
2079 | return 0; | |
2080 | } | |
2081 | ||
54e9c9d4 | 2082 | int bpf_prog_array_copy_info(struct bpf_prog_array *array, |
3a38bb98 YS |
2083 | u32 *prog_ids, u32 request_cnt, |
2084 | u32 *prog_cnt) | |
f371b304 YS |
2085 | { |
2086 | u32 cnt = 0; | |
2087 | ||
2088 | if (array) | |
2089 | cnt = bpf_prog_array_length(array); | |
2090 | ||
3a38bb98 | 2091 | *prog_cnt = cnt; |
f371b304 YS |
2092 | |
2093 | /* return early if user requested only program count or nothing to copy */ | |
2094 | if (!request_cnt || !cnt) | |
2095 | return 0; | |
2096 | ||
3a38bb98 | 2097 | /* this function is called under trace/bpf_trace.c: bpf_event_mutex */ |
394e40a2 | 2098 | return bpf_prog_array_copy_core(array, prog_ids, request_cnt) ? -ENOSPC |
3a38bb98 | 2099 | : 0; |
f371b304 YS |
2100 | } |
2101 | ||
a2ea0746 DB |
2102 | void __bpf_free_used_maps(struct bpf_prog_aux *aux, |
2103 | struct bpf_map **used_maps, u32 len) | |
6332be04 | 2104 | { |
da765a2f | 2105 | struct bpf_map *map; |
a2ea0746 | 2106 | u32 i; |
6332be04 | 2107 | |
a2ea0746 DB |
2108 | for (i = 0; i < len; i++) { |
2109 | map = used_maps[i]; | |
da765a2f DB |
2110 | if (map->ops->map_poke_untrack) |
2111 | map->ops->map_poke_untrack(map, aux); | |
2112 | bpf_map_put(map); | |
2113 | } | |
a2ea0746 DB |
2114 | } |
2115 | ||
2116 | static void bpf_free_used_maps(struct bpf_prog_aux *aux) | |
2117 | { | |
2118 | __bpf_free_used_maps(aux, aux->used_maps, aux->used_map_cnt); | |
6332be04 DB |
2119 | kfree(aux->used_maps); |
2120 | } | |
2121 | ||
60a3b225 DB |
2122 | static void bpf_prog_free_deferred(struct work_struct *work) |
2123 | { | |
09756af4 | 2124 | struct bpf_prog_aux *aux; |
1c2a088a | 2125 | int i; |
60a3b225 | 2126 | |
09756af4 | 2127 | aux = container_of(work, struct bpf_prog_aux, work); |
6332be04 | 2128 | bpf_free_used_maps(aux); |
ab3f0063 JK |
2129 | if (bpf_prog_is_dev_bound(aux)) |
2130 | bpf_prog_offload_destroy(aux->prog); | |
c195651e YS |
2131 | #ifdef CONFIG_PERF_EVENTS |
2132 | if (aux->prog->has_callchain_buf) | |
2133 | put_callchain_buffers(); | |
2134 | #endif | |
3aac1ead THJ |
2135 | if (aux->dst_trampoline) |
2136 | bpf_trampoline_put(aux->dst_trampoline); | |
1c2a088a AS |
2137 | for (i = 0; i < aux->func_cnt; i++) |
2138 | bpf_jit_free(aux->func[i]); | |
2139 | if (aux->func_cnt) { | |
2140 | kfree(aux->func); | |
2141 | bpf_prog_unlock_free(aux->prog); | |
2142 | } else { | |
2143 | bpf_jit_free(aux->prog); | |
2144 | } | |
60a3b225 DB |
2145 | } |
2146 | ||
2147 | /* Free internal BPF program */ | |
7ae457c1 | 2148 | void bpf_prog_free(struct bpf_prog *fp) |
f5bffecd | 2149 | { |
09756af4 | 2150 | struct bpf_prog_aux *aux = fp->aux; |
60a3b225 | 2151 | |
3aac1ead THJ |
2152 | if (aux->dst_prog) |
2153 | bpf_prog_put(aux->dst_prog); | |
09756af4 | 2154 | INIT_WORK(&aux->work, bpf_prog_free_deferred); |
09756af4 | 2155 | schedule_work(&aux->work); |
f5bffecd | 2156 | } |
7ae457c1 | 2157 | EXPORT_SYMBOL_GPL(bpf_prog_free); |
f89b7755 | 2158 | |
3ad00405 DB |
2159 | /* RNG for unpriviledged user space with separated state from prandom_u32(). */ |
2160 | static DEFINE_PER_CPU(struct rnd_state, bpf_user_rnd_state); | |
2161 | ||
2162 | void bpf_user_rnd_init_once(void) | |
2163 | { | |
2164 | prandom_init_once(&bpf_user_rnd_state); | |
2165 | } | |
2166 | ||
f3694e00 | 2167 | BPF_CALL_0(bpf_user_rnd_u32) |
3ad00405 DB |
2168 | { |
2169 | /* Should someone ever have the rather unwise idea to use some | |
2170 | * of the registers passed into this function, then note that | |
2171 | * this function is called from native eBPF and classic-to-eBPF | |
2172 | * transformations. Register assignments from both sides are | |
2173 | * different, f.e. classic always sets fn(ctx, A, X) here. | |
2174 | */ | |
2175 | struct rnd_state *state; | |
2176 | u32 res; | |
2177 | ||
2178 | state = &get_cpu_var(bpf_user_rnd_state); | |
2179 | res = prandom_u32_state(state); | |
b761fe22 | 2180 | put_cpu_var(bpf_user_rnd_state); |
3ad00405 DB |
2181 | |
2182 | return res; | |
2183 | } | |
2184 | ||
6890896b SF |
2185 | BPF_CALL_0(bpf_get_raw_cpu_id) |
2186 | { | |
2187 | return raw_smp_processor_id(); | |
2188 | } | |
2189 | ||
3ba67dab DB |
2190 | /* Weak definitions of helper functions in case we don't have bpf syscall. */ |
2191 | const struct bpf_func_proto bpf_map_lookup_elem_proto __weak; | |
2192 | const struct bpf_func_proto bpf_map_update_elem_proto __weak; | |
2193 | const struct bpf_func_proto bpf_map_delete_elem_proto __weak; | |
f1a2e44a MV |
2194 | const struct bpf_func_proto bpf_map_push_elem_proto __weak; |
2195 | const struct bpf_func_proto bpf_map_pop_elem_proto __weak; | |
2196 | const struct bpf_func_proto bpf_map_peek_elem_proto __weak; | |
d83525ca AS |
2197 | const struct bpf_func_proto bpf_spin_lock_proto __weak; |
2198 | const struct bpf_func_proto bpf_spin_unlock_proto __weak; | |
5576b991 | 2199 | const struct bpf_func_proto bpf_jiffies64_proto __weak; |
3ba67dab | 2200 | |
03e69b50 | 2201 | const struct bpf_func_proto bpf_get_prandom_u32_proto __weak; |
c04167ce | 2202 | const struct bpf_func_proto bpf_get_smp_processor_id_proto __weak; |
2d0e30c3 | 2203 | const struct bpf_func_proto bpf_get_numa_node_id_proto __weak; |
17ca8cbf | 2204 | const struct bpf_func_proto bpf_ktime_get_ns_proto __weak; |
71d19214 | 2205 | const struct bpf_func_proto bpf_ktime_get_boot_ns_proto __weak; |
d0551261 | 2206 | const struct bpf_func_proto bpf_ktime_get_coarse_ns_proto __weak; |
bd570ff9 | 2207 | |
ffeedafb AS |
2208 | const struct bpf_func_proto bpf_get_current_pid_tgid_proto __weak; |
2209 | const struct bpf_func_proto bpf_get_current_uid_gid_proto __weak; | |
2210 | const struct bpf_func_proto bpf_get_current_comm_proto __weak; | |
bf6fa2c8 | 2211 | const struct bpf_func_proto bpf_get_current_cgroup_id_proto __weak; |
0f09abd1 | 2212 | const struct bpf_func_proto bpf_get_current_ancestor_cgroup_id_proto __weak; |
cd339431 | 2213 | const struct bpf_func_proto bpf_get_local_storage_proto __weak; |
b4490c5c | 2214 | const struct bpf_func_proto bpf_get_ns_current_pid_tgid_proto __weak; |
c4d0bfb4 | 2215 | const struct bpf_func_proto bpf_snprintf_btf_proto __weak; |
eb411377 | 2216 | const struct bpf_func_proto bpf_seq_printf_btf_proto __weak; |
bd570ff9 | 2217 | |
0756ea3e AS |
2218 | const struct bpf_func_proto * __weak bpf_get_trace_printk_proto(void) |
2219 | { | |
2220 | return NULL; | |
2221 | } | |
03e69b50 | 2222 | |
555c8a86 DB |
2223 | u64 __weak |
2224 | bpf_event_output(struct bpf_map *map, u64 flags, void *meta, u64 meta_size, | |
2225 | void *ctx, u64 ctx_size, bpf_ctx_copy_t ctx_copy) | |
bd570ff9 | 2226 | { |
555c8a86 | 2227 | return -ENOTSUPP; |
bd570ff9 | 2228 | } |
6cb5fb38 | 2229 | EXPORT_SYMBOL_GPL(bpf_event_output); |
bd570ff9 | 2230 | |
3324b584 DB |
2231 | /* Always built-in helper functions. */ |
2232 | const struct bpf_func_proto bpf_tail_call_proto = { | |
2233 | .func = NULL, | |
2234 | .gpl_only = false, | |
2235 | .ret_type = RET_VOID, | |
2236 | .arg1_type = ARG_PTR_TO_CTX, | |
2237 | .arg2_type = ARG_CONST_MAP_PTR, | |
2238 | .arg3_type = ARG_ANYTHING, | |
2239 | }; | |
2240 | ||
9383191d DB |
2241 | /* Stub for JITs that only support cBPF. eBPF programs are interpreted. |
2242 | * It is encouraged to implement bpf_int_jit_compile() instead, so that | |
2243 | * eBPF and implicitly also cBPF can get JITed! | |
2244 | */ | |
d1c55ab5 | 2245 | struct bpf_prog * __weak bpf_int_jit_compile(struct bpf_prog *prog) |
3324b584 | 2246 | { |
d1c55ab5 | 2247 | return prog; |
3324b584 DB |
2248 | } |
2249 | ||
9383191d DB |
2250 | /* Stub for JITs that support eBPF. All cBPF code gets transformed into |
2251 | * eBPF by the kernel and is later compiled by bpf_int_jit_compile(). | |
2252 | */ | |
2253 | void __weak bpf_jit_compile(struct bpf_prog *prog) | |
2254 | { | |
2255 | } | |
2256 | ||
17bedab2 | 2257 | bool __weak bpf_helper_changes_pkt_data(void *func) |
969bf05e AS |
2258 | { |
2259 | return false; | |
2260 | } | |
2261 | ||
a4b1d3c1 JW |
2262 | /* Return TRUE if the JIT backend wants verifier to enable sub-register usage |
2263 | * analysis code and wants explicit zero extension inserted by verifier. | |
2264 | * Otherwise, return FALSE. | |
2265 | */ | |
2266 | bool __weak bpf_jit_needs_zext(void) | |
2267 | { | |
2268 | return false; | |
2269 | } | |
2270 | ||
f89b7755 AS |
2271 | /* To execute LD_ABS/LD_IND instructions __bpf_prog_run() may call |
2272 | * skb_copy_bits(), so provide a weak definition of it for NET-less config. | |
2273 | */ | |
2274 | int __weak skb_copy_bits(const struct sk_buff *skb, int offset, void *to, | |
2275 | int len) | |
2276 | { | |
2277 | return -EFAULT; | |
2278 | } | |
a67edbf4 | 2279 | |
5964b200 AS |
2280 | int __weak bpf_arch_text_poke(void *ip, enum bpf_text_poke_type t, |
2281 | void *addr1, void *addr2) | |
2282 | { | |
2283 | return -ENOTSUPP; | |
2284 | } | |
2285 | ||
492ecee8 AS |
2286 | DEFINE_STATIC_KEY_FALSE(bpf_stats_enabled_key); |
2287 | EXPORT_SYMBOL(bpf_stats_enabled_key); | |
492ecee8 | 2288 | |
a67edbf4 DB |
2289 | /* All definitions of tracepoints related to BPF. */ |
2290 | #define CREATE_TRACE_POINTS | |
2291 | #include <linux/bpf_trace.h> | |
2292 | ||
2293 | EXPORT_TRACEPOINT_SYMBOL_GPL(xdp_exception); | |
e7d47989 | 2294 | EXPORT_TRACEPOINT_SYMBOL_GPL(xdp_bulk_tx); |