blob: 97e37d82a1cc587619b0e4769adabd73b04e7d2a [file] [log] [blame]
Thomas Gleixner2874c5f2019-05-27 08:55:01 +02001// SPDX-License-Identifier: GPL-2.0-or-later
Alexei Starovoitovf5bffec2014-07-22 23:01:58 -07002/*
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 *
Alexei Starovoitovf5bffec2014-07-22 23:01:58 -070016 * Andi Kleen - Fix a few bad bugs and races.
Alexei Starovoitov4df95ff2014-07-30 20:34:14 -070017 * Kris Katterjohn - Added many additional checks in bpf_check_classic()
Alexei Starovoitovf5bffec2014-07-22 23:01:58 -070018 */
Daniel Borkmann738cbe72014-09-08 08:04:47 +020019
Yonghong Song838e9692018-11-19 15:29:11 -080020#include <uapi/linux/btf.h>
Alexei Starovoitovf5bffec2014-07-22 23:01:58 -070021#include <linux/filter.h>
22#include <linux/skbuff.h>
Daniel Borkmann60a3b222014-09-02 22:53:44 +020023#include <linux/vmalloc.h>
Daniel Borkmann738cbe72014-09-08 08:04:47 +020024#include <linux/random.h>
25#include <linux/moduleloader.h>
Alexei Starovoitov09756af2014-09-26 00:17:00 -070026#include <linux/bpf.h>
Yonghong Song838e9692018-11-19 15:29:11 -080027#include <linux/btf.h>
Josh Poimboeuf39853cc2016-02-28 22:22:37 -060028#include <linux/frame.h>
Daniel Borkmann74451e662017-02-16 22:24:50 +010029#include <linux/rbtree_latch.h>
30#include <linux/kallsyms.h>
31#include <linux/rcupdate.h>
Yonghong Songc195651e2018-04-28 22:28:08 -070032#include <linux/perf_event.h>
Alexei Starovoitov3dec5412019-10-15 20:25:03 -070033#include <linux/extable.h>
Daniel Borkmann3324b582015-05-29 23:23:07 +020034#include <asm/unaligned.h>
35
Alexei Starovoitovf5bffec2014-07-22 23:01:58 -070036/* Registers */
37#define BPF_R0 regs[BPF_REG_0]
38#define BPF_R1 regs[BPF_REG_1]
39#define BPF_R2 regs[BPF_REG_2]
40#define BPF_R3 regs[BPF_REG_3]
41#define BPF_R4 regs[BPF_REG_4]
42#define BPF_R5 regs[BPF_REG_5]
43#define BPF_R6 regs[BPF_REG_6]
44#define BPF_R7 regs[BPF_REG_7]
45#define BPF_R8 regs[BPF_REG_8]
46#define BPF_R9 regs[BPF_REG_9]
47#define BPF_R10 regs[BPF_REG_10]
48
49/* Named registers */
50#define DST regs[insn->dst_reg]
51#define SRC regs[insn->src_reg]
52#define FP regs[BPF_REG_FP]
Daniel Borkmann144cd912019-01-03 00:58:28 +010053#define AX regs[BPF_REG_AX]
Alexei Starovoitovf5bffec2014-07-22 23:01:58 -070054#define ARG1 regs[BPF_REG_ARG1]
55#define CTX regs[BPF_REG_CTX]
56#define IMM insn->imm
57
58/* No hurry in this branch
59 *
60 * Exported for the bpf jit load helper.
61 */
62void *bpf_internal_load_pointer_neg_helper(const struct sk_buff *skb, int k, unsigned int size)
63{
64 u8 *ptr = NULL;
65
66 if (k >= SKF_NET_OFF)
67 ptr = skb_network_header(skb) + k - SKF_NET_OFF;
68 else if (k >= SKF_LL_OFF)
69 ptr = skb_mac_header(skb) + k - SKF_LL_OFF;
Daniel Borkmann3324b582015-05-29 23:23:07 +020070
Alexei Starovoitovf5bffec2014-07-22 23:01:58 -070071 if (ptr >= skb->head && ptr + size <= skb_tail_pointer(skb))
72 return ptr;
73
74 return NULL;
75}
76
Alexei Starovoitov492ecee2019-02-25 14:28:39 -080077struct bpf_prog *bpf_prog_alloc_no_stats(unsigned int size, gfp_t gfp_extra_flags)
Daniel Borkmann60a3b222014-09-02 22:53:44 +020078{
Michal Hocko19809c22017-05-08 15:57:44 -070079 gfp_t gfp_flags = GFP_KERNEL | __GFP_ZERO | gfp_extra_flags;
Alexei Starovoitov09756af2014-09-26 00:17:00 -070080 struct bpf_prog_aux *aux;
Daniel Borkmann60a3b222014-09-02 22:53:44 +020081 struct bpf_prog *fp;
82
83 size = round_up(size, PAGE_SIZE);
84 fp = __vmalloc(size, gfp_flags, PAGE_KERNEL);
85 if (fp == NULL)
86 return NULL;
87
Alexei Starovoitov09756af2014-09-26 00:17:00 -070088 aux = kzalloc(sizeof(*aux), GFP_KERNEL | gfp_extra_flags);
89 if (aux == NULL) {
Daniel Borkmann60a3b222014-09-02 22:53:44 +020090 vfree(fp);
91 return NULL;
92 }
93
94 fp->pages = size / PAGE_SIZE;
Alexei Starovoitov09756af2014-09-26 00:17:00 -070095 fp->aux = aux;
Daniel Borkmanne9d8afa2015-10-29 14:58:08 +010096 fp->aux->prog = fp;
Alexei Starovoitov60b58afc2017-12-14 17:55:14 -080097 fp->jit_requested = ebpf_jit_enabled();
Daniel Borkmann60a3b222014-09-02 22:53:44 +020098
Daniel Borkmann74451e662017-02-16 22:24:50 +010099 INIT_LIST_HEAD_RCU(&fp->aux->ksym_lnode);
100
Daniel Borkmann60a3b222014-09-02 22:53:44 +0200101 return fp;
102}
Alexei Starovoitov492ecee2019-02-25 14:28:39 -0800103
104struct bpf_prog *bpf_prog_alloc(unsigned int size, gfp_t gfp_extra_flags)
105{
106 gfp_t gfp_flags = GFP_KERNEL | __GFP_ZERO | gfp_extra_flags;
107 struct bpf_prog *prog;
Eric Dumazet4b911302019-03-01 14:33:11 -0800108 int cpu;
Alexei Starovoitov492ecee2019-02-25 14:28:39 -0800109
110 prog = bpf_prog_alloc_no_stats(size, gfp_extra_flags);
111 if (!prog)
112 return NULL;
113
114 prog->aux->stats = alloc_percpu_gfp(struct bpf_prog_stats, gfp_flags);
115 if (!prog->aux->stats) {
116 kfree(prog->aux);
117 vfree(prog);
118 return NULL;
119 }
120
Eric Dumazet4b911302019-03-01 14:33:11 -0800121 for_each_possible_cpu(cpu) {
122 struct bpf_prog_stats *pstats;
123
124 pstats = per_cpu_ptr(prog->aux->stats, cpu);
125 u64_stats_init(&pstats->syncp);
126 }
Alexei Starovoitov492ecee2019-02-25 14:28:39 -0800127 return prog;
128}
Daniel Borkmann60a3b222014-09-02 22:53:44 +0200129EXPORT_SYMBOL_GPL(bpf_prog_alloc);
130
Martin KaFai Lauc454a462018-12-07 16:42:25 -0800131int bpf_prog_alloc_jited_linfo(struct bpf_prog *prog)
132{
133 if (!prog->aux->nr_linfo || !prog->jit_requested)
134 return 0;
135
136 prog->aux->jited_linfo = kcalloc(prog->aux->nr_linfo,
137 sizeof(*prog->aux->jited_linfo),
138 GFP_KERNEL | __GFP_NOWARN);
139 if (!prog->aux->jited_linfo)
140 return -ENOMEM;
141
142 return 0;
143}
144
145void bpf_prog_free_jited_linfo(struct bpf_prog *prog)
146{
147 kfree(prog->aux->jited_linfo);
148 prog->aux->jited_linfo = NULL;
149}
150
151void bpf_prog_free_unused_jited_linfo(struct bpf_prog *prog)
152{
153 if (prog->aux->jited_linfo && !prog->aux->jited_linfo[0])
154 bpf_prog_free_jited_linfo(prog);
155}
156
157/* The jit engine is responsible to provide an array
158 * for insn_off to the jited_off mapping (insn_to_jit_off).
159 *
160 * The idx to this array is the insn_off. Hence, the insn_off
161 * here is relative to the prog itself instead of the main prog.
162 * This array has one entry for each xlated bpf insn.
163 *
164 * jited_off is the byte off to the last byte of the jited insn.
165 *
166 * Hence, with
167 * insn_start:
168 * The first bpf insn off of the prog. The insn off
169 * here is relative to the main prog.
170 * e.g. if prog is a subprog, insn_start > 0
171 * linfo_idx:
172 * The prog's idx to prog->aux->linfo and jited_linfo
173 *
174 * jited_linfo[linfo_idx] = prog->bpf_func
175 *
176 * For i > linfo_idx,
177 *
178 * jited_linfo[i] = prog->bpf_func +
179 * insn_to_jit_off[linfo[i].insn_off - insn_start - 1]
180 */
181void bpf_prog_fill_jited_linfo(struct bpf_prog *prog,
182 const u32 *insn_to_jit_off)
183{
184 u32 linfo_idx, insn_start, insn_end, nr_linfo, i;
185 const struct bpf_line_info *linfo;
186 void **jited_linfo;
187
188 if (!prog->aux->jited_linfo)
189 /* Userspace did not provide linfo */
190 return;
191
192 linfo_idx = prog->aux->linfo_idx;
193 linfo = &prog->aux->linfo[linfo_idx];
194 insn_start = linfo[0].insn_off;
195 insn_end = insn_start + prog->len;
196
197 jited_linfo = &prog->aux->jited_linfo[linfo_idx];
198 jited_linfo[0] = prog->bpf_func;
199
200 nr_linfo = prog->aux->nr_linfo - linfo_idx;
201
202 for (i = 1; i < nr_linfo && linfo[i].insn_off < insn_end; i++)
203 /* The verifier ensures that linfo[i].insn_off is
204 * strictly increasing
205 */
206 jited_linfo[i] = prog->bpf_func +
207 insn_to_jit_off[linfo[i].insn_off - insn_start - 1];
208}
209
210void bpf_prog_free_linfo(struct bpf_prog *prog)
211{
212 bpf_prog_free_jited_linfo(prog);
213 kvfree(prog->aux->linfo);
214}
215
Daniel Borkmann60a3b222014-09-02 22:53:44 +0200216struct bpf_prog *bpf_prog_realloc(struct bpf_prog *fp_old, unsigned int size,
217 gfp_t gfp_extra_flags)
218{
Michal Hocko19809c22017-05-08 15:57:44 -0700219 gfp_t gfp_flags = GFP_KERNEL | __GFP_ZERO | gfp_extra_flags;
Daniel Borkmann60a3b222014-09-02 22:53:44 +0200220 struct bpf_prog *fp;
Daniel Borkmann5ccb0712016-12-18 01:52:58 +0100221 u32 pages, delta;
222 int ret;
Daniel Borkmann60a3b222014-09-02 22:53:44 +0200223
224 BUG_ON(fp_old == NULL);
225
226 size = round_up(size, PAGE_SIZE);
Daniel Borkmann5ccb0712016-12-18 01:52:58 +0100227 pages = size / PAGE_SIZE;
228 if (pages <= fp_old->pages)
Daniel Borkmann60a3b222014-09-02 22:53:44 +0200229 return fp_old;
230
Daniel Borkmann5ccb0712016-12-18 01:52:58 +0100231 delta = pages - fp_old->pages;
232 ret = __bpf_prog_charge(fp_old->aux->user, delta);
233 if (ret)
234 return NULL;
235
Daniel Borkmann60a3b222014-09-02 22:53:44 +0200236 fp = __vmalloc(size, gfp_flags, PAGE_KERNEL);
Daniel Borkmann5ccb0712016-12-18 01:52:58 +0100237 if (fp == NULL) {
238 __bpf_prog_uncharge(fp_old->aux->user, delta);
239 } else {
Daniel Borkmann60a3b222014-09-02 22:53:44 +0200240 memcpy(fp, fp_old, fp_old->pages * PAGE_SIZE);
Daniel Borkmann5ccb0712016-12-18 01:52:58 +0100241 fp->pages = pages;
Daniel Borkmanne9d8afa2015-10-29 14:58:08 +0100242 fp->aux->prog = fp;
Daniel Borkmann60a3b222014-09-02 22:53:44 +0200243
Alexei Starovoitov09756af2014-09-26 00:17:00 -0700244 /* We keep fp->aux from fp_old around in the new
Daniel Borkmann60a3b222014-09-02 22:53:44 +0200245 * reallocated structure.
246 */
Alexei Starovoitov09756af2014-09-26 00:17:00 -0700247 fp_old->aux = NULL;
Daniel Borkmann60a3b222014-09-02 22:53:44 +0200248 __bpf_prog_free(fp_old);
249 }
250
251 return fp;
252}
Daniel Borkmann60a3b222014-09-02 22:53:44 +0200253
254void __bpf_prog_free(struct bpf_prog *fp)
255{
Alexei Starovoitov492ecee2019-02-25 14:28:39 -0800256 if (fp->aux) {
257 free_percpu(fp->aux->stats);
258 kfree(fp->aux);
259 }
Daniel Borkmann60a3b222014-09-02 22:53:44 +0200260 vfree(fp);
261}
Daniel Borkmann60a3b222014-09-02 22:53:44 +0200262
Daniel Borkmannf1f77142017-01-13 23:38:15 +0100263int bpf_prog_calc_tag(struct bpf_prog *fp)
Daniel Borkmann7bd509e2016-12-04 23:19:41 +0100264{
265 const u32 bits_offset = SHA_MESSAGE_BYTES - sizeof(__be64);
Daniel Borkmannf1f77142017-01-13 23:38:15 +0100266 u32 raw_size = bpf_prog_tag_scratch_size(fp);
267 u32 digest[SHA_DIGEST_WORDS];
Daniel Borkmannaafe6ae2016-12-18 01:52:57 +0100268 u32 ws[SHA_WORKSPACE_WORDS];
Daniel Borkmann7bd509e2016-12-04 23:19:41 +0100269 u32 i, bsize, psize, blocks;
Daniel Borkmannaafe6ae2016-12-18 01:52:57 +0100270 struct bpf_insn *dst;
Daniel Borkmann7bd509e2016-12-04 23:19:41 +0100271 bool was_ld_map;
Daniel Borkmannaafe6ae2016-12-18 01:52:57 +0100272 u8 *raw, *todo;
Daniel Borkmann7bd509e2016-12-04 23:19:41 +0100273 __be32 *result;
274 __be64 *bits;
275
Daniel Borkmannaafe6ae2016-12-18 01:52:57 +0100276 raw = vmalloc(raw_size);
277 if (!raw)
278 return -ENOMEM;
279
Daniel Borkmannf1f77142017-01-13 23:38:15 +0100280 sha_init(digest);
Daniel Borkmann7bd509e2016-12-04 23:19:41 +0100281 memset(ws, 0, sizeof(ws));
282
283 /* We need to take out the map fd for the digest calculation
284 * since they are unstable from user space side.
285 */
Daniel Borkmannaafe6ae2016-12-18 01:52:57 +0100286 dst = (void *)raw;
Daniel Borkmann7bd509e2016-12-04 23:19:41 +0100287 for (i = 0, was_ld_map = false; i < fp->len; i++) {
288 dst[i] = fp->insnsi[i];
289 if (!was_ld_map &&
290 dst[i].code == (BPF_LD | BPF_IMM | BPF_DW) &&
Daniel Borkmannd8eca5b2019-04-09 23:20:03 +0200291 (dst[i].src_reg == BPF_PSEUDO_MAP_FD ||
292 dst[i].src_reg == BPF_PSEUDO_MAP_VALUE)) {
Daniel Borkmann7bd509e2016-12-04 23:19:41 +0100293 was_ld_map = true;
294 dst[i].imm = 0;
295 } else if (was_ld_map &&
296 dst[i].code == 0 &&
297 dst[i].dst_reg == 0 &&
298 dst[i].src_reg == 0 &&
299 dst[i].off == 0) {
300 was_ld_map = false;
301 dst[i].imm = 0;
302 } else {
303 was_ld_map = false;
304 }
305 }
306
Daniel Borkmannaafe6ae2016-12-18 01:52:57 +0100307 psize = bpf_prog_insn_size(fp);
308 memset(&raw[psize], 0, raw_size - psize);
Daniel Borkmann7bd509e2016-12-04 23:19:41 +0100309 raw[psize++] = 0x80;
310
311 bsize = round_up(psize, SHA_MESSAGE_BYTES);
312 blocks = bsize / SHA_MESSAGE_BYTES;
Daniel Borkmannaafe6ae2016-12-18 01:52:57 +0100313 todo = raw;
Daniel Borkmann7bd509e2016-12-04 23:19:41 +0100314 if (bsize - psize >= sizeof(__be64)) {
315 bits = (__be64 *)(todo + bsize - sizeof(__be64));
316 } else {
317 bits = (__be64 *)(todo + bsize + bits_offset);
318 blocks++;
319 }
320 *bits = cpu_to_be64((psize - 1) << 3);
321
322 while (blocks--) {
Daniel Borkmannf1f77142017-01-13 23:38:15 +0100323 sha_transform(digest, todo, ws);
Daniel Borkmann7bd509e2016-12-04 23:19:41 +0100324 todo += SHA_MESSAGE_BYTES;
325 }
326
Daniel Borkmannf1f77142017-01-13 23:38:15 +0100327 result = (__force __be32 *)digest;
Daniel Borkmann7bd509e2016-12-04 23:19:41 +0100328 for (i = 0; i < SHA_DIGEST_WORDS; i++)
Daniel Borkmannf1f77142017-01-13 23:38:15 +0100329 result[i] = cpu_to_be32(digest[i]);
330 memcpy(fp->tag, result, sizeof(fp->tag));
Daniel Borkmannaafe6ae2016-12-18 01:52:57 +0100331
332 vfree(raw);
333 return 0;
Daniel Borkmann7bd509e2016-12-04 23:19:41 +0100334}
335
Jakub Kicinski2cbd95a2019-01-22 22:45:18 -0800336static int bpf_adj_delta_to_imm(struct bpf_insn *insn, u32 pos, s32 end_old,
Daniel Borkmannaf959b12019-05-11 03:03:09 +0200337 s32 end_new, s32 curr, const bool probe_pass)
Daniel Borkmannc237ee52016-05-13 19:08:30 +0200338{
Daniel Borkmann050fad72018-05-17 01:44:11 +0200339 const s64 imm_min = S32_MIN, imm_max = S32_MAX;
Jakub Kicinski2cbd95a2019-01-22 22:45:18 -0800340 s32 delta = end_new - end_old;
Daniel Borkmann050fad72018-05-17 01:44:11 +0200341 s64 imm = insn->imm;
342
Jakub Kicinski2cbd95a2019-01-22 22:45:18 -0800343 if (curr < pos && curr + imm + 1 >= end_old)
Daniel Borkmann050fad72018-05-17 01:44:11 +0200344 imm += delta;
Jakub Kicinski2cbd95a2019-01-22 22:45:18 -0800345 else if (curr >= end_new && curr + imm + 1 < end_new)
Daniel Borkmann050fad72018-05-17 01:44:11 +0200346 imm -= delta;
347 if (imm < imm_min || imm > imm_max)
348 return -ERANGE;
349 if (!probe_pass)
350 insn->imm = imm;
351 return 0;
352}
353
Jakub Kicinski2cbd95a2019-01-22 22:45:18 -0800354static int bpf_adj_delta_to_off(struct bpf_insn *insn, u32 pos, s32 end_old,
Daniel Borkmannaf959b12019-05-11 03:03:09 +0200355 s32 end_new, s32 curr, const bool probe_pass)
Daniel Borkmann050fad72018-05-17 01:44:11 +0200356{
357 const s32 off_min = S16_MIN, off_max = S16_MAX;
Jakub Kicinski2cbd95a2019-01-22 22:45:18 -0800358 s32 delta = end_new - end_old;
Daniel Borkmann050fad72018-05-17 01:44:11 +0200359 s32 off = insn->off;
360
Jakub Kicinski2cbd95a2019-01-22 22:45:18 -0800361 if (curr < pos && curr + off + 1 >= end_old)
Daniel Borkmann050fad72018-05-17 01:44:11 +0200362 off += delta;
Jakub Kicinski2cbd95a2019-01-22 22:45:18 -0800363 else if (curr >= end_new && curr + off + 1 < end_new)
Daniel Borkmann050fad72018-05-17 01:44:11 +0200364 off -= delta;
365 if (off < off_min || off > off_max)
366 return -ERANGE;
367 if (!probe_pass)
368 insn->off = off;
369 return 0;
370}
371
Jakub Kicinski2cbd95a2019-01-22 22:45:18 -0800372static int bpf_adj_branches(struct bpf_prog *prog, u32 pos, s32 end_old,
373 s32 end_new, const bool probe_pass)
Daniel Borkmann050fad72018-05-17 01:44:11 +0200374{
Jakub Kicinski2cbd95a2019-01-22 22:45:18 -0800375 u32 i, insn_cnt = prog->len + (probe_pass ? end_new - end_old : 0);
Daniel Borkmannc237ee52016-05-13 19:08:30 +0200376 struct bpf_insn *insn = prog->insnsi;
Daniel Borkmann050fad72018-05-17 01:44:11 +0200377 int ret = 0;
Daniel Borkmannc237ee52016-05-13 19:08:30 +0200378
379 for (i = 0; i < insn_cnt; i++, insn++) {
Daniel Borkmann050fad72018-05-17 01:44:11 +0200380 u8 code;
381
382 /* In the probing pass we still operate on the original,
383 * unpatched image in order to check overflows before we
384 * do any other adjustments. Therefore skip the patchlet.
385 */
386 if (probe_pass && i == pos) {
Jakub Kicinski2cbd95a2019-01-22 22:45:18 -0800387 i = end_new;
388 insn = prog->insnsi + end_old;
Alexei Starovoitov1ea47e02017-12-14 17:55:13 -0800389 }
Daniel Borkmann050fad72018-05-17 01:44:11 +0200390 code = insn->code;
Jiong Wang092ed092019-01-26 12:26:01 -0500391 if ((BPF_CLASS(code) != BPF_JMP &&
392 BPF_CLASS(code) != BPF_JMP32) ||
Daniel Borkmann050fad72018-05-17 01:44:11 +0200393 BPF_OP(code) == BPF_EXIT)
394 continue;
395 /* Adjust offset of jmps if we cross patch boundaries. */
396 if (BPF_OP(code) == BPF_CALL) {
397 if (insn->src_reg != BPF_PSEUDO_CALL)
398 continue;
Jakub Kicinski2cbd95a2019-01-22 22:45:18 -0800399 ret = bpf_adj_delta_to_imm(insn, pos, end_old,
400 end_new, i, probe_pass);
Daniel Borkmann050fad72018-05-17 01:44:11 +0200401 } else {
Jakub Kicinski2cbd95a2019-01-22 22:45:18 -0800402 ret = bpf_adj_delta_to_off(insn, pos, end_old,
403 end_new, i, probe_pass);
Daniel Borkmann050fad72018-05-17 01:44:11 +0200404 }
405 if (ret)
406 break;
Daniel Borkmannc237ee52016-05-13 19:08:30 +0200407 }
Daniel Borkmann050fad72018-05-17 01:44:11 +0200408
409 return ret;
Daniel Borkmannc237ee52016-05-13 19:08:30 +0200410}
411
Martin KaFai Lauc454a462018-12-07 16:42:25 -0800412static void bpf_adj_linfo(struct bpf_prog *prog, u32 off, u32 delta)
413{
414 struct bpf_line_info *linfo;
415 u32 i, nr_linfo;
416
417 nr_linfo = prog->aux->nr_linfo;
418 if (!nr_linfo || !delta)
419 return;
420
421 linfo = prog->aux->linfo;
422
423 for (i = 0; i < nr_linfo; i++)
424 if (off < linfo[i].insn_off)
425 break;
426
427 /* Push all off < linfo[i].insn_off by delta */
428 for (; i < nr_linfo; i++)
429 linfo[i].insn_off += delta;
430}
431
Daniel Borkmannc237ee52016-05-13 19:08:30 +0200432struct bpf_prog *bpf_patch_insn_single(struct bpf_prog *prog, u32 off,
433 const struct bpf_insn *patch, u32 len)
434{
435 u32 insn_adj_cnt, insn_rest, insn_delta = len - 1;
Daniel Borkmann050fad72018-05-17 01:44:11 +0200436 const u32 cnt_max = S16_MAX;
Daniel Borkmannc237ee52016-05-13 19:08:30 +0200437 struct bpf_prog *prog_adj;
Alexei Starovoitov4f733792019-04-01 21:27:44 -0700438 int err;
Daniel Borkmannc237ee52016-05-13 19:08:30 +0200439
440 /* Since our patchlet doesn't expand the image, we're done. */
441 if (insn_delta == 0) {
442 memcpy(prog->insnsi + off, patch, sizeof(*patch));
443 return prog;
444 }
445
446 insn_adj_cnt = prog->len + insn_delta;
447
Daniel Borkmann050fad72018-05-17 01:44:11 +0200448 /* Reject anything that would potentially let the insn->off
449 * target overflow when we have excessive program expansions.
450 * We need to probe here before we do any reallocation where
451 * we afterwards may not fail anymore.
452 */
453 if (insn_adj_cnt > cnt_max &&
Alexei Starovoitov4f733792019-04-01 21:27:44 -0700454 (err = bpf_adj_branches(prog, off, off + 1, off + len, true)))
455 return ERR_PTR(err);
Daniel Borkmann050fad72018-05-17 01:44:11 +0200456
Daniel Borkmannc237ee52016-05-13 19:08:30 +0200457 /* Several new instructions need to be inserted. Make room
458 * for them. Likely, there's no need for a new allocation as
459 * last page could have large enough tailroom.
460 */
461 prog_adj = bpf_prog_realloc(prog, bpf_prog_size(insn_adj_cnt),
462 GFP_USER);
463 if (!prog_adj)
Alexei Starovoitov4f733792019-04-01 21:27:44 -0700464 return ERR_PTR(-ENOMEM);
Daniel Borkmannc237ee52016-05-13 19:08:30 +0200465
466 prog_adj->len = insn_adj_cnt;
467
468 /* Patching happens in 3 steps:
469 *
470 * 1) Move over tail of insnsi from next instruction onwards,
471 * so we can patch the single target insn with one or more
472 * new ones (patching is always from 1 to n insns, n > 0).
473 * 2) Inject new instructions at the target location.
474 * 3) Adjust branch offsets if necessary.
475 */
476 insn_rest = insn_adj_cnt - off - len;
477
478 memmove(prog_adj->insnsi + off + len, prog_adj->insnsi + off + 1,
479 sizeof(*patch) * insn_rest);
480 memcpy(prog_adj->insnsi + off, patch, sizeof(*patch) * len);
481
Daniel Borkmann050fad72018-05-17 01:44:11 +0200482 /* We are guaranteed to not fail at this point, otherwise
483 * the ship has sailed to reverse to the original state. An
484 * overflow cannot happen at this point.
485 */
Jakub Kicinski2cbd95a2019-01-22 22:45:18 -0800486 BUG_ON(bpf_adj_branches(prog_adj, off, off + 1, off + len, false));
Daniel Borkmannc237ee52016-05-13 19:08:30 +0200487
Martin KaFai Lauc454a462018-12-07 16:42:25 -0800488 bpf_adj_linfo(prog_adj, off, insn_delta);
489
Daniel Borkmannc237ee52016-05-13 19:08:30 +0200490 return prog_adj;
491}
492
Jakub Kicinski52875a02019-01-22 22:45:20 -0800493int bpf_remove_insns(struct bpf_prog *prog, u32 off, u32 cnt)
494{
495 /* Branch offsets can't overflow when program is shrinking, no need
496 * to call bpf_adj_branches(..., true) here
497 */
498 memmove(prog->insnsi + off, prog->insnsi + off + cnt,
499 sizeof(struct bpf_insn) * (prog->len - off - cnt));
500 prog->len -= cnt;
501
502 return WARN_ON_ONCE(bpf_adj_branches(prog, off, off + cnt, off, false));
503}
504
Daniel Borkmanncd7455f2019-10-22 15:57:23 +0200505static void bpf_prog_kallsyms_del_subprogs(struct bpf_prog *fp)
Daniel Borkmann7d1982b2018-06-15 02:30:47 +0200506{
507 int i;
508
509 for (i = 0; i < fp->aux->func_cnt; i++)
510 bpf_prog_kallsyms_del(fp->aux->func[i]);
511}
512
513void bpf_prog_kallsyms_del_all(struct bpf_prog *fp)
514{
515 bpf_prog_kallsyms_del_subprogs(fp);
516 bpf_prog_kallsyms_del(fp);
517}
518
Daniel Borkmannb954d832014-09-10 15:01:02 +0200519#ifdef CONFIG_BPF_JIT
Daniel Borkmannfa9dd592018-01-20 01:24:33 +0100520/* All BPF JIT sysctl knobs here. */
521int bpf_jit_enable __read_mostly = IS_BUILTIN(CONFIG_BPF_JIT_ALWAYS_ON);
522int bpf_jit_harden __read_mostly;
523int bpf_jit_kallsyms __read_mostly;
Daniel Borkmannfdadd042018-12-11 12:14:12 +0100524long bpf_jit_limit __read_mostly;
Daniel Borkmannfa9dd592018-01-20 01:24:33 +0100525
Daniel Borkmann74451e662017-02-16 22:24:50 +0100526static __always_inline void
527bpf_get_prog_addr_region(const struct bpf_prog *prog,
528 unsigned long *symbol_start,
529 unsigned long *symbol_end)
530{
531 const struct bpf_binary_header *hdr = bpf_jit_binary_hdr(prog);
532 unsigned long addr = (unsigned long)hdr;
533
534 WARN_ON_ONCE(!bpf_prog_ebpf_jited(prog));
535
536 *symbol_start = addr;
537 *symbol_end = addr + hdr->pages * PAGE_SIZE;
538}
539
Song Liu6ee52e22019-01-17 08:15:15 -0800540void bpf_get_prog_name(const struct bpf_prog *prog, char *sym)
Daniel Borkmann74451e662017-02-16 22:24:50 +0100541{
Martin KaFai Lau368211f2017-10-05 21:52:13 -0700542 const char *end = sym + KSYM_NAME_LEN;
Yonghong Song838e9692018-11-19 15:29:11 -0800543 const struct btf_type *type;
544 const char *func_name;
Martin KaFai Lau368211f2017-10-05 21:52:13 -0700545
Daniel Borkmann74451e662017-02-16 22:24:50 +0100546 BUILD_BUG_ON(sizeof("bpf_prog_") +
Martin KaFai Lau368211f2017-10-05 21:52:13 -0700547 sizeof(prog->tag) * 2 +
548 /* name has been null terminated.
549 * We should need +1 for the '_' preceding
550 * the name. However, the null character
551 * is double counted between the name and the
552 * sizeof("bpf_prog_") above, so we omit
553 * the +1 here.
554 */
555 sizeof(prog->aux->name) > KSYM_NAME_LEN);
Daniel Borkmann74451e662017-02-16 22:24:50 +0100556
557 sym += snprintf(sym, KSYM_NAME_LEN, "bpf_prog_");
558 sym = bin2hex(sym, prog->tag, sizeof(prog->tag));
Yonghong Song838e9692018-11-19 15:29:11 -0800559
560 /* prog->aux->name will be ignored if full btf name is available */
Martin KaFai Lau73372242018-12-05 17:35:43 -0800561 if (prog->aux->func_info_cnt) {
Yonghong Songba64e7d2018-11-24 23:20:44 -0800562 type = btf_type_by_id(prog->aux->btf,
563 prog->aux->func_info[prog->aux->func_idx].type_id);
Yonghong Song838e9692018-11-19 15:29:11 -0800564 func_name = btf_name_by_offset(prog->aux->btf, type->name_off);
565 snprintf(sym, (size_t)(end - sym), "_%s", func_name);
566 return;
567 }
568
Martin KaFai Lau368211f2017-10-05 21:52:13 -0700569 if (prog->aux->name[0])
570 snprintf(sym, (size_t)(end - sym), "_%s", prog->aux->name);
571 else
572 *sym = 0;
Daniel Borkmann74451e662017-02-16 22:24:50 +0100573}
574
575static __always_inline unsigned long
576bpf_get_prog_addr_start(struct latch_tree_node *n)
577{
578 unsigned long symbol_start, symbol_end;
579 const struct bpf_prog_aux *aux;
580
581 aux = container_of(n, struct bpf_prog_aux, ksym_tnode);
582 bpf_get_prog_addr_region(aux->prog, &symbol_start, &symbol_end);
583
584 return symbol_start;
585}
586
587static __always_inline bool bpf_tree_less(struct latch_tree_node *a,
588 struct latch_tree_node *b)
589{
590 return bpf_get_prog_addr_start(a) < bpf_get_prog_addr_start(b);
591}
592
593static __always_inline int bpf_tree_comp(void *key, struct latch_tree_node *n)
594{
595 unsigned long val = (unsigned long)key;
596 unsigned long symbol_start, symbol_end;
597 const struct bpf_prog_aux *aux;
598
599 aux = container_of(n, struct bpf_prog_aux, ksym_tnode);
600 bpf_get_prog_addr_region(aux->prog, &symbol_start, &symbol_end);
601
602 if (val < symbol_start)
603 return -1;
604 if (val >= symbol_end)
605 return 1;
606
607 return 0;
608}
609
610static const struct latch_tree_ops bpf_tree_ops = {
611 .less = bpf_tree_less,
612 .comp = bpf_tree_comp,
613};
614
615static DEFINE_SPINLOCK(bpf_lock);
616static LIST_HEAD(bpf_kallsyms);
617static struct latch_tree_root bpf_tree __cacheline_aligned;
618
Daniel Borkmann74451e662017-02-16 22:24:50 +0100619static void bpf_prog_ksym_node_add(struct bpf_prog_aux *aux)
620{
621 WARN_ON_ONCE(!list_empty(&aux->ksym_lnode));
622 list_add_tail_rcu(&aux->ksym_lnode, &bpf_kallsyms);
623 latch_tree_insert(&aux->ksym_tnode, &bpf_tree, &bpf_tree_ops);
624}
625
626static void bpf_prog_ksym_node_del(struct bpf_prog_aux *aux)
627{
628 if (list_empty(&aux->ksym_lnode))
629 return;
630
631 latch_tree_erase(&aux->ksym_tnode, &bpf_tree, &bpf_tree_ops);
632 list_del_rcu(&aux->ksym_lnode);
633}
634
635static bool bpf_prog_kallsyms_candidate(const struct bpf_prog *fp)
636{
637 return fp->jited && !bpf_prog_was_classic(fp);
638}
639
640static bool bpf_prog_kallsyms_verify_off(const struct bpf_prog *fp)
641{
642 return list_empty(&fp->aux->ksym_lnode) ||
643 fp->aux->ksym_lnode.prev == LIST_POISON2;
644}
645
646void bpf_prog_kallsyms_add(struct bpf_prog *fp)
647{
Daniel Borkmann74451e662017-02-16 22:24:50 +0100648 if (!bpf_prog_kallsyms_candidate(fp) ||
649 !capable(CAP_SYS_ADMIN))
650 return;
651
Hannes Frederic Sowad24f7c72017-04-27 01:39:33 +0200652 spin_lock_bh(&bpf_lock);
Daniel Borkmann74451e662017-02-16 22:24:50 +0100653 bpf_prog_ksym_node_add(fp->aux);
Hannes Frederic Sowad24f7c72017-04-27 01:39:33 +0200654 spin_unlock_bh(&bpf_lock);
Daniel Borkmann74451e662017-02-16 22:24:50 +0100655}
656
657void bpf_prog_kallsyms_del(struct bpf_prog *fp)
658{
Daniel Borkmann74451e662017-02-16 22:24:50 +0100659 if (!bpf_prog_kallsyms_candidate(fp))
660 return;
661
Hannes Frederic Sowad24f7c72017-04-27 01:39:33 +0200662 spin_lock_bh(&bpf_lock);
Daniel Borkmann74451e662017-02-16 22:24:50 +0100663 bpf_prog_ksym_node_del(fp->aux);
Hannes Frederic Sowad24f7c72017-04-27 01:39:33 +0200664 spin_unlock_bh(&bpf_lock);
Daniel Borkmann74451e662017-02-16 22:24:50 +0100665}
666
667static struct bpf_prog *bpf_prog_kallsyms_find(unsigned long addr)
668{
669 struct latch_tree_node *n;
670
Daniel Borkmann74451e662017-02-16 22:24:50 +0100671 n = latch_tree_find((void *)addr, &bpf_tree, &bpf_tree_ops);
672 return n ?
673 container_of(n, struct bpf_prog_aux, ksym_tnode)->prog :
674 NULL;
675}
676
677const char *__bpf_address_lookup(unsigned long addr, unsigned long *size,
678 unsigned long *off, char *sym)
679{
680 unsigned long symbol_start, symbol_end;
681 struct bpf_prog *prog;
682 char *ret = NULL;
683
684 rcu_read_lock();
685 prog = bpf_prog_kallsyms_find(addr);
686 if (prog) {
687 bpf_get_prog_addr_region(prog, &symbol_start, &symbol_end);
688 bpf_get_prog_name(prog, sym);
689
690 ret = sym;
691 if (size)
692 *size = symbol_end - symbol_start;
693 if (off)
694 *off = addr - symbol_start;
695 }
696 rcu_read_unlock();
697
698 return ret;
699}
700
701bool is_bpf_text_address(unsigned long addr)
702{
703 bool ret;
704
705 rcu_read_lock();
706 ret = bpf_prog_kallsyms_find(addr) != NULL;
707 rcu_read_unlock();
708
709 return ret;
710}
711
Alexei Starovoitov3dec5412019-10-15 20:25:03 -0700712const struct exception_table_entry *search_bpf_extables(unsigned long addr)
713{
714 const struct exception_table_entry *e = NULL;
715 struct bpf_prog *prog;
716
717 rcu_read_lock();
718 prog = bpf_prog_kallsyms_find(addr);
719 if (!prog)
720 goto out;
721 if (!prog->aux->num_exentries)
722 goto out;
723
724 e = search_extable(prog->aux->extable, prog->aux->num_exentries, addr);
725out:
726 rcu_read_unlock();
727 return e;
728}
729
Daniel Borkmann74451e662017-02-16 22:24:50 +0100730int bpf_get_kallsym(unsigned int symnum, unsigned long *value, char *type,
731 char *sym)
732{
Daniel Borkmann74451e662017-02-16 22:24:50 +0100733 struct bpf_prog_aux *aux;
734 unsigned int it = 0;
735 int ret = -ERANGE;
736
737 if (!bpf_jit_kallsyms_enabled())
738 return ret;
739
740 rcu_read_lock();
741 list_for_each_entry_rcu(aux, &bpf_kallsyms, ksym_lnode) {
742 if (it++ != symnum)
743 continue;
744
Daniel Borkmann74451e662017-02-16 22:24:50 +0100745 bpf_get_prog_name(aux->prog, sym);
746
Song Liudf073472018-11-02 10:16:15 -0700747 *value = (unsigned long)aux->prog->bpf_func;
Daniel Borkmann74451e662017-02-16 22:24:50 +0100748 *type = BPF_SYM_ELF_TYPE;
749
750 ret = 0;
751 break;
752 }
753 rcu_read_unlock();
754
755 return ret;
756}
757
Daniel Borkmannede95a632018-10-23 01:11:04 +0200758static atomic_long_t bpf_jit_current;
759
Daniel Borkmannfdadd042018-12-11 12:14:12 +0100760/* Can be overridden by an arch's JIT compiler if it has a custom,
761 * dedicated BPF backend memory area, or if neither of the two
762 * below apply.
763 */
764u64 __weak bpf_jit_alloc_exec_limit(void)
765{
Daniel Borkmannede95a632018-10-23 01:11:04 +0200766#if defined(MODULES_VADDR)
Daniel Borkmannfdadd042018-12-11 12:14:12 +0100767 return MODULES_END - MODULES_VADDR;
768#else
769 return VMALLOC_END - VMALLOC_START;
770#endif
771}
772
Daniel Borkmannede95a632018-10-23 01:11:04 +0200773static int __init bpf_jit_charge_init(void)
774{
775 /* Only used as heuristic here to derive limit. */
Daniel Borkmannfdadd042018-12-11 12:14:12 +0100776 bpf_jit_limit = min_t(u64, round_up(bpf_jit_alloc_exec_limit() >> 2,
777 PAGE_SIZE), LONG_MAX);
Daniel Borkmannede95a632018-10-23 01:11:04 +0200778 return 0;
779}
780pure_initcall(bpf_jit_charge_init);
Daniel Borkmannede95a632018-10-23 01:11:04 +0200781
782static int bpf_jit_charge_modmem(u32 pages)
783{
784 if (atomic_long_add_return(pages, &bpf_jit_current) >
785 (bpf_jit_limit >> PAGE_SHIFT)) {
786 if (!capable(CAP_SYS_ADMIN)) {
787 atomic_long_sub(pages, &bpf_jit_current);
788 return -EPERM;
789 }
790 }
791
792 return 0;
793}
794
795static void bpf_jit_uncharge_modmem(u32 pages)
796{
797 atomic_long_sub(pages, &bpf_jit_current);
798}
799
Ard Biesheuveldc002bb2018-11-23 23:18:03 +0100800void *__weak bpf_jit_alloc_exec(unsigned long size)
801{
802 return module_alloc(size);
803}
804
805void __weak bpf_jit_free_exec(void *addr)
806{
807 module_memfree(addr);
808}
809
Daniel Borkmann738cbe72014-09-08 08:04:47 +0200810struct bpf_binary_header *
811bpf_jit_binary_alloc(unsigned int proglen, u8 **image_ptr,
812 unsigned int alignment,
813 bpf_jit_fill_hole_t bpf_fill_ill_insns)
814{
815 struct bpf_binary_header *hdr;
Daniel Borkmannede95a632018-10-23 01:11:04 +0200816 u32 size, hole, start, pages;
Daniel Borkmann738cbe72014-09-08 08:04:47 +0200817
818 /* Most of BPF filters are really small, but if some of them
819 * fill a page, allow at least 128 extra bytes to insert a
820 * random section of illegal instructions.
821 */
822 size = round_up(proglen + sizeof(*hdr) + 128, PAGE_SIZE);
Daniel Borkmannede95a632018-10-23 01:11:04 +0200823 pages = size / PAGE_SIZE;
824
825 if (bpf_jit_charge_modmem(pages))
Daniel Borkmann738cbe72014-09-08 08:04:47 +0200826 return NULL;
Ard Biesheuveldc002bb2018-11-23 23:18:03 +0100827 hdr = bpf_jit_alloc_exec(size);
Daniel Borkmannede95a632018-10-23 01:11:04 +0200828 if (!hdr) {
829 bpf_jit_uncharge_modmem(pages);
830 return NULL;
831 }
Daniel Borkmann738cbe72014-09-08 08:04:47 +0200832
833 /* Fill space with illegal/arch-dep instructions. */
834 bpf_fill_ill_insns(hdr, size);
835
Daniel Borkmannede95a632018-10-23 01:11:04 +0200836 hdr->pages = pages;
Daniel Borkmann738cbe72014-09-08 08:04:47 +0200837 hole = min_t(unsigned int, size - (proglen + sizeof(*hdr)),
838 PAGE_SIZE - sizeof(*hdr));
Daniel Borkmannb7552e1b2016-05-18 14:14:28 +0200839 start = (get_random_int() % hole) & ~(alignment - 1);
Daniel Borkmann738cbe72014-09-08 08:04:47 +0200840
841 /* Leave a random number of instructions before BPF code. */
842 *image_ptr = &hdr->image[start];
843
844 return hdr;
845}
846
847void bpf_jit_binary_free(struct bpf_binary_header *hdr)
848{
Daniel Borkmannede95a632018-10-23 01:11:04 +0200849 u32 pages = hdr->pages;
850
Ard Biesheuveldc002bb2018-11-23 23:18:03 +0100851 bpf_jit_free_exec(hdr);
Daniel Borkmannede95a632018-10-23 01:11:04 +0200852 bpf_jit_uncharge_modmem(pages);
Daniel Borkmann738cbe72014-09-08 08:04:47 +0200853}
Daniel Borkmann4f3446b2016-05-13 19:08:32 +0200854
Daniel Borkmann74451e662017-02-16 22:24:50 +0100855/* This symbol is only overridden by archs that have different
856 * requirements than the usual eBPF JITs, f.e. when they only
857 * implement cBPF JIT, do not set images read-only, etc.
858 */
859void __weak bpf_jit_free(struct bpf_prog *fp)
860{
861 if (fp->jited) {
862 struct bpf_binary_header *hdr = bpf_jit_binary_hdr(fp);
863
Daniel Borkmann74451e662017-02-16 22:24:50 +0100864 bpf_jit_binary_free(hdr);
865
866 WARN_ON_ONCE(!bpf_prog_kallsyms_verify_off(fp));
867 }
868
869 bpf_prog_unlock_free(fp);
870}
871
Daniel Borkmanne2c95a62018-11-26 14:05:38 +0100872int bpf_jit_get_func_addr(const struct bpf_prog *prog,
873 const struct bpf_insn *insn, bool extra_pass,
874 u64 *func_addr, bool *func_addr_fixed)
875{
876 s16 off = insn->off;
877 s32 imm = insn->imm;
878 u8 *addr;
879
880 *func_addr_fixed = insn->src_reg != BPF_PSEUDO_CALL;
881 if (!*func_addr_fixed) {
882 /* Place-holder address till the last pass has collected
883 * all addresses for JITed subprograms in which case we
884 * can pick them up from prog->aux.
885 */
886 if (!extra_pass)
887 addr = NULL;
888 else if (prog->aux->func &&
889 off >= 0 && off < prog->aux->func_cnt)
890 addr = (u8 *)prog->aux->func[off]->bpf_func;
891 else
892 return -EINVAL;
893 } else {
894 /* Address of a BPF helper call. Since part of the core
895 * kernel, it's always at a fixed location. __bpf_call_base
896 * and the helper with imm relative to it are both in core
897 * kernel.
898 */
899 addr = (u8 *)__bpf_call_base + imm;
900 }
901
902 *func_addr = (unsigned long)addr;
903 return 0;
904}
905
Daniel Borkmann4f3446b2016-05-13 19:08:32 +0200906static int bpf_jit_blind_insn(const struct bpf_insn *from,
907 const struct bpf_insn *aux,
Naveen N. Raoede7c462019-08-22 00:53:58 +0530908 struct bpf_insn *to_buff,
909 bool emit_zext)
Daniel Borkmann4f3446b2016-05-13 19:08:32 +0200910{
911 struct bpf_insn *to = to_buff;
Daniel Borkmannb7552e1b2016-05-18 14:14:28 +0200912 u32 imm_rnd = get_random_int();
Daniel Borkmann4f3446b2016-05-13 19:08:32 +0200913 s16 off;
914
915 BUILD_BUG_ON(BPF_REG_AX + 1 != MAX_BPF_JIT_REG);
916 BUILD_BUG_ON(MAX_BPF_REG + 1 != MAX_BPF_JIT_REG);
917
Daniel Borkmann9b73bfd2019-01-03 00:58:29 +0100918 /* Constraints on AX register:
919 *
920 * AX register is inaccessible from user space. It is mapped in
921 * all JITs, and used here for constant blinding rewrites. It is
922 * typically "stateless" meaning its contents are only valid within
923 * the executed instruction, but not across several instructions.
924 * There are a few exceptions however which are further detailed
925 * below.
926 *
927 * Constant blinding is only used by JITs, not in the interpreter.
928 * The interpreter uses AX in some occasions as a local temporary
929 * register e.g. in DIV or MOD instructions.
930 *
931 * In restricted circumstances, the verifier can also use the AX
932 * register for rewrites as long as they do not interfere with
933 * the above cases!
934 */
935 if (from->dst_reg == BPF_REG_AX || from->src_reg == BPF_REG_AX)
936 goto out;
937
Daniel Borkmann4f3446b2016-05-13 19:08:32 +0200938 if (from->imm == 0 &&
939 (from->code == (BPF_ALU | BPF_MOV | BPF_K) ||
940 from->code == (BPF_ALU64 | BPF_MOV | BPF_K))) {
941 *to++ = BPF_ALU64_REG(BPF_XOR, from->dst_reg, from->dst_reg);
942 goto out;
943 }
944
945 switch (from->code) {
946 case BPF_ALU | BPF_ADD | BPF_K:
947 case BPF_ALU | BPF_SUB | BPF_K:
948 case BPF_ALU | BPF_AND | BPF_K:
949 case BPF_ALU | BPF_OR | BPF_K:
950 case BPF_ALU | BPF_XOR | BPF_K:
951 case BPF_ALU | BPF_MUL | BPF_K:
952 case BPF_ALU | BPF_MOV | BPF_K:
953 case BPF_ALU | BPF_DIV | BPF_K:
954 case BPF_ALU | BPF_MOD | BPF_K:
955 *to++ = BPF_ALU32_IMM(BPF_MOV, BPF_REG_AX, imm_rnd ^ from->imm);
956 *to++ = BPF_ALU32_IMM(BPF_XOR, BPF_REG_AX, imm_rnd);
957 *to++ = BPF_ALU32_REG(from->code, from->dst_reg, BPF_REG_AX);
958 break;
959
960 case BPF_ALU64 | BPF_ADD | BPF_K:
961 case BPF_ALU64 | BPF_SUB | BPF_K:
962 case BPF_ALU64 | BPF_AND | BPF_K:
963 case BPF_ALU64 | BPF_OR | BPF_K:
964 case BPF_ALU64 | BPF_XOR | BPF_K:
965 case BPF_ALU64 | BPF_MUL | BPF_K:
966 case BPF_ALU64 | BPF_MOV | BPF_K:
967 case BPF_ALU64 | BPF_DIV | BPF_K:
968 case BPF_ALU64 | BPF_MOD | BPF_K:
969 *to++ = BPF_ALU64_IMM(BPF_MOV, BPF_REG_AX, imm_rnd ^ from->imm);
970 *to++ = BPF_ALU64_IMM(BPF_XOR, BPF_REG_AX, imm_rnd);
971 *to++ = BPF_ALU64_REG(from->code, from->dst_reg, BPF_REG_AX);
972 break;
973
974 case BPF_JMP | BPF_JEQ | BPF_K:
975 case BPF_JMP | BPF_JNE | BPF_K:
976 case BPF_JMP | BPF_JGT | BPF_K:
Daniel Borkmann92b31a92017-08-10 01:39:55 +0200977 case BPF_JMP | BPF_JLT | BPF_K:
Daniel Borkmann4f3446b2016-05-13 19:08:32 +0200978 case BPF_JMP | BPF_JGE | BPF_K:
Daniel Borkmann92b31a92017-08-10 01:39:55 +0200979 case BPF_JMP | BPF_JLE | BPF_K:
Daniel Borkmann4f3446b2016-05-13 19:08:32 +0200980 case BPF_JMP | BPF_JSGT | BPF_K:
Daniel Borkmann92b31a92017-08-10 01:39:55 +0200981 case BPF_JMP | BPF_JSLT | BPF_K:
Daniel Borkmann4f3446b2016-05-13 19:08:32 +0200982 case BPF_JMP | BPF_JSGE | BPF_K:
Daniel Borkmann92b31a92017-08-10 01:39:55 +0200983 case BPF_JMP | BPF_JSLE | BPF_K:
Daniel Borkmann4f3446b2016-05-13 19:08:32 +0200984 case BPF_JMP | BPF_JSET | BPF_K:
985 /* Accommodate for extra offset in case of a backjump. */
986 off = from->off;
987 if (off < 0)
988 off -= 2;
989 *to++ = BPF_ALU64_IMM(BPF_MOV, BPF_REG_AX, imm_rnd ^ from->imm);
990 *to++ = BPF_ALU64_IMM(BPF_XOR, BPF_REG_AX, imm_rnd);
991 *to++ = BPF_JMP_REG(from->code, from->dst_reg, BPF_REG_AX, off);
992 break;
993
Jiong Wanga7b76c82019-01-26 12:26:05 -0500994 case BPF_JMP32 | BPF_JEQ | BPF_K:
995 case BPF_JMP32 | BPF_JNE | BPF_K:
996 case BPF_JMP32 | BPF_JGT | BPF_K:
997 case BPF_JMP32 | BPF_JLT | BPF_K:
998 case BPF_JMP32 | BPF_JGE | BPF_K:
999 case BPF_JMP32 | BPF_JLE | BPF_K:
1000 case BPF_JMP32 | BPF_JSGT | BPF_K:
1001 case BPF_JMP32 | BPF_JSLT | BPF_K:
1002 case BPF_JMP32 | BPF_JSGE | BPF_K:
1003 case BPF_JMP32 | BPF_JSLE | BPF_K:
1004 case BPF_JMP32 | BPF_JSET | BPF_K:
1005 /* Accommodate for extra offset in case of a backjump. */
1006 off = from->off;
1007 if (off < 0)
1008 off -= 2;
1009 *to++ = BPF_ALU32_IMM(BPF_MOV, BPF_REG_AX, imm_rnd ^ from->imm);
1010 *to++ = BPF_ALU32_IMM(BPF_XOR, BPF_REG_AX, imm_rnd);
1011 *to++ = BPF_JMP32_REG(from->code, from->dst_reg, BPF_REG_AX,
1012 off);
1013 break;
1014
Daniel Borkmann4f3446b2016-05-13 19:08:32 +02001015 case BPF_LD | BPF_IMM | BPF_DW:
1016 *to++ = BPF_ALU64_IMM(BPF_MOV, BPF_REG_AX, imm_rnd ^ aux[1].imm);
1017 *to++ = BPF_ALU64_IMM(BPF_XOR, BPF_REG_AX, imm_rnd);
1018 *to++ = BPF_ALU64_IMM(BPF_LSH, BPF_REG_AX, 32);
1019 *to++ = BPF_ALU64_REG(BPF_MOV, aux[0].dst_reg, BPF_REG_AX);
1020 break;
1021 case 0: /* Part 2 of BPF_LD | BPF_IMM | BPF_DW. */
1022 *to++ = BPF_ALU32_IMM(BPF_MOV, BPF_REG_AX, imm_rnd ^ aux[0].imm);
1023 *to++ = BPF_ALU32_IMM(BPF_XOR, BPF_REG_AX, imm_rnd);
Naveen N. Raoede7c462019-08-22 00:53:58 +05301024 if (emit_zext)
1025 *to++ = BPF_ZEXT_REG(BPF_REG_AX);
Daniel Borkmann4f3446b2016-05-13 19:08:32 +02001026 *to++ = BPF_ALU64_REG(BPF_OR, aux[0].dst_reg, BPF_REG_AX);
1027 break;
1028
1029 case BPF_ST | BPF_MEM | BPF_DW:
1030 case BPF_ST | BPF_MEM | BPF_W:
1031 case BPF_ST | BPF_MEM | BPF_H:
1032 case BPF_ST | BPF_MEM | BPF_B:
1033 *to++ = BPF_ALU64_IMM(BPF_MOV, BPF_REG_AX, imm_rnd ^ from->imm);
1034 *to++ = BPF_ALU64_IMM(BPF_XOR, BPF_REG_AX, imm_rnd);
1035 *to++ = BPF_STX_MEM(from->code, from->dst_reg, BPF_REG_AX, from->off);
1036 break;
1037 }
1038out:
1039 return to - to_buff;
1040}
1041
1042static struct bpf_prog *bpf_prog_clone_create(struct bpf_prog *fp_other,
1043 gfp_t gfp_extra_flags)
1044{
Michal Hocko19809c22017-05-08 15:57:44 -07001045 gfp_t gfp_flags = GFP_KERNEL | __GFP_ZERO | gfp_extra_flags;
Daniel Borkmann4f3446b2016-05-13 19:08:32 +02001046 struct bpf_prog *fp;
1047
1048 fp = __vmalloc(fp_other->pages * PAGE_SIZE, gfp_flags, PAGE_KERNEL);
1049 if (fp != NULL) {
Daniel Borkmann4f3446b2016-05-13 19:08:32 +02001050 /* aux->prog still points to the fp_other one, so
1051 * when promoting the clone to the real program,
1052 * this still needs to be adapted.
1053 */
1054 memcpy(fp, fp_other, fp_other->pages * PAGE_SIZE);
1055 }
1056
1057 return fp;
1058}
1059
1060static void bpf_prog_clone_free(struct bpf_prog *fp)
1061{
1062 /* aux was stolen by the other clone, so we cannot free
1063 * it from this path! It will be freed eventually by the
1064 * other program on release.
1065 *
1066 * At this point, we don't need a deferred release since
1067 * clone is guaranteed to not be locked.
1068 */
1069 fp->aux = NULL;
1070 __bpf_prog_free(fp);
1071}
1072
1073void bpf_jit_prog_release_other(struct bpf_prog *fp, struct bpf_prog *fp_other)
1074{
1075 /* We have to repoint aux->prog to self, as we don't
1076 * know whether fp here is the clone or the original.
1077 */
1078 fp->aux->prog = fp;
1079 bpf_prog_clone_free(fp_other);
1080}
1081
1082struct bpf_prog *bpf_jit_blind_constants(struct bpf_prog *prog)
1083{
1084 struct bpf_insn insn_buff[16], aux[2];
1085 struct bpf_prog *clone, *tmp;
1086 int insn_delta, insn_cnt;
1087 struct bpf_insn *insn;
1088 int i, rewritten;
1089
Alexei Starovoitov1c2a0882017-12-14 17:55:15 -08001090 if (!bpf_jit_blinding_enabled(prog) || prog->blinded)
Daniel Borkmann4f3446b2016-05-13 19:08:32 +02001091 return prog;
1092
1093 clone = bpf_prog_clone_create(prog, GFP_USER);
1094 if (!clone)
1095 return ERR_PTR(-ENOMEM);
1096
1097 insn_cnt = clone->len;
1098 insn = clone->insnsi;
1099
1100 for (i = 0; i < insn_cnt; i++, insn++) {
1101 /* We temporarily need to hold the original ld64 insn
1102 * so that we can still access the first part in the
1103 * second blinding run.
1104 */
1105 if (insn[0].code == (BPF_LD | BPF_IMM | BPF_DW) &&
1106 insn[1].code == 0)
1107 memcpy(aux, insn, sizeof(aux));
1108
Naveen N. Raoede7c462019-08-22 00:53:58 +05301109 rewritten = bpf_jit_blind_insn(insn, aux, insn_buff,
1110 clone->aux->verifier_zext);
Daniel Borkmann4f3446b2016-05-13 19:08:32 +02001111 if (!rewritten)
1112 continue;
1113
1114 tmp = bpf_patch_insn_single(clone, i, insn_buff, rewritten);
Alexei Starovoitov4f733792019-04-01 21:27:44 -07001115 if (IS_ERR(tmp)) {
Daniel Borkmann4f3446b2016-05-13 19:08:32 +02001116 /* Patching may have repointed aux->prog during
1117 * realloc from the original one, so we need to
1118 * fix it up here on error.
1119 */
1120 bpf_jit_prog_release_other(prog, clone);
Alexei Starovoitov4f733792019-04-01 21:27:44 -07001121 return tmp;
Daniel Borkmann4f3446b2016-05-13 19:08:32 +02001122 }
1123
1124 clone = tmp;
1125 insn_delta = rewritten - 1;
1126
1127 /* Walk new program and skip insns we just inserted. */
1128 insn = clone->insnsi + i + insn_delta;
1129 insn_cnt += insn_delta;
1130 i += insn_delta;
1131 }
1132
Alexei Starovoitov1c2a0882017-12-14 17:55:15 -08001133 clone->blinded = 1;
Daniel Borkmann4f3446b2016-05-13 19:08:32 +02001134 return clone;
1135}
Daniel Borkmannb954d832014-09-10 15:01:02 +02001136#endif /* CONFIG_BPF_JIT */
Daniel Borkmann738cbe72014-09-08 08:04:47 +02001137
Alexei Starovoitovf5bffec2014-07-22 23:01:58 -07001138/* Base function for offset calculation. Needs to go into .text section,
1139 * therefore keeping it non-static as well; will also be used by JITs
Daniel Borkmann7105e822017-12-20 13:42:57 +01001140 * anyway later on, so do not let the compiler omit it. This also needs
1141 * to go into kallsyms for correlation from e.g. bpftool, so naming
1142 * must not change.
Alexei Starovoitovf5bffec2014-07-22 23:01:58 -07001143 */
1144noinline u64 __bpf_call_base(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5)
1145{
1146 return 0;
1147}
Alexei Starovoitov4d9c5c52015-07-20 20:34:19 -07001148EXPORT_SYMBOL_GPL(__bpf_call_base);
Alexei Starovoitovf5bffec2014-07-22 23:01:58 -07001149
Daniel Borkmann5e581da2018-01-26 23:33:38 +01001150/* All UAPI available opcodes. */
1151#define BPF_INSN_MAP(INSN_2, INSN_3) \
1152 /* 32 bit ALU operations. */ \
1153 /* Register based. */ \
Jiong Wang2dc6b102018-12-05 13:52:34 -05001154 INSN_3(ALU, ADD, X), \
1155 INSN_3(ALU, SUB, X), \
1156 INSN_3(ALU, AND, X), \
1157 INSN_3(ALU, OR, X), \
1158 INSN_3(ALU, LSH, X), \
1159 INSN_3(ALU, RSH, X), \
1160 INSN_3(ALU, XOR, X), \
1161 INSN_3(ALU, MUL, X), \
1162 INSN_3(ALU, MOV, X), \
1163 INSN_3(ALU, ARSH, X), \
1164 INSN_3(ALU, DIV, X), \
1165 INSN_3(ALU, MOD, X), \
Daniel Borkmann5e581da2018-01-26 23:33:38 +01001166 INSN_2(ALU, NEG), \
1167 INSN_3(ALU, END, TO_BE), \
1168 INSN_3(ALU, END, TO_LE), \
1169 /* Immediate based. */ \
Jiong Wang2dc6b102018-12-05 13:52:34 -05001170 INSN_3(ALU, ADD, K), \
1171 INSN_3(ALU, SUB, K), \
1172 INSN_3(ALU, AND, K), \
1173 INSN_3(ALU, OR, K), \
1174 INSN_3(ALU, LSH, K), \
1175 INSN_3(ALU, RSH, K), \
1176 INSN_3(ALU, XOR, K), \
1177 INSN_3(ALU, MUL, K), \
1178 INSN_3(ALU, MOV, K), \
1179 INSN_3(ALU, ARSH, K), \
1180 INSN_3(ALU, DIV, K), \
1181 INSN_3(ALU, MOD, K), \
Daniel Borkmann5e581da2018-01-26 23:33:38 +01001182 /* 64 bit ALU operations. */ \
1183 /* Register based. */ \
1184 INSN_3(ALU64, ADD, X), \
1185 INSN_3(ALU64, SUB, X), \
1186 INSN_3(ALU64, AND, X), \
1187 INSN_3(ALU64, OR, X), \
1188 INSN_3(ALU64, LSH, X), \
1189 INSN_3(ALU64, RSH, X), \
1190 INSN_3(ALU64, XOR, X), \
1191 INSN_3(ALU64, MUL, X), \
1192 INSN_3(ALU64, MOV, X), \
1193 INSN_3(ALU64, ARSH, X), \
1194 INSN_3(ALU64, DIV, X), \
1195 INSN_3(ALU64, MOD, X), \
1196 INSN_2(ALU64, NEG), \
1197 /* Immediate based. */ \
1198 INSN_3(ALU64, ADD, K), \
1199 INSN_3(ALU64, SUB, K), \
1200 INSN_3(ALU64, AND, K), \
1201 INSN_3(ALU64, OR, K), \
1202 INSN_3(ALU64, LSH, K), \
1203 INSN_3(ALU64, RSH, K), \
1204 INSN_3(ALU64, XOR, K), \
1205 INSN_3(ALU64, MUL, K), \
1206 INSN_3(ALU64, MOV, K), \
1207 INSN_3(ALU64, ARSH, K), \
1208 INSN_3(ALU64, DIV, K), \
1209 INSN_3(ALU64, MOD, K), \
1210 /* Call instruction. */ \
1211 INSN_2(JMP, CALL), \
1212 /* Exit instruction. */ \
1213 INSN_2(JMP, EXIT), \
Jiong Wang503a8862019-01-26 12:26:04 -05001214 /* 32-bit Jump instructions. */ \
1215 /* Register based. */ \
1216 INSN_3(JMP32, JEQ, X), \
1217 INSN_3(JMP32, JNE, X), \
1218 INSN_3(JMP32, JGT, X), \
1219 INSN_3(JMP32, JLT, X), \
1220 INSN_3(JMP32, JGE, X), \
1221 INSN_3(JMP32, JLE, X), \
1222 INSN_3(JMP32, JSGT, X), \
1223 INSN_3(JMP32, JSLT, X), \
1224 INSN_3(JMP32, JSGE, X), \
1225 INSN_3(JMP32, JSLE, X), \
1226 INSN_3(JMP32, JSET, X), \
1227 /* Immediate based. */ \
1228 INSN_3(JMP32, JEQ, K), \
1229 INSN_3(JMP32, JNE, K), \
1230 INSN_3(JMP32, JGT, K), \
1231 INSN_3(JMP32, JLT, K), \
1232 INSN_3(JMP32, JGE, K), \
1233 INSN_3(JMP32, JLE, K), \
1234 INSN_3(JMP32, JSGT, K), \
1235 INSN_3(JMP32, JSLT, K), \
1236 INSN_3(JMP32, JSGE, K), \
1237 INSN_3(JMP32, JSLE, K), \
1238 INSN_3(JMP32, JSET, K), \
Daniel Borkmann5e581da2018-01-26 23:33:38 +01001239 /* Jump instructions. */ \
1240 /* Register based. */ \
1241 INSN_3(JMP, JEQ, X), \
1242 INSN_3(JMP, JNE, X), \
1243 INSN_3(JMP, JGT, X), \
1244 INSN_3(JMP, JLT, X), \
1245 INSN_3(JMP, JGE, X), \
1246 INSN_3(JMP, JLE, X), \
1247 INSN_3(JMP, JSGT, X), \
1248 INSN_3(JMP, JSLT, X), \
1249 INSN_3(JMP, JSGE, X), \
1250 INSN_3(JMP, JSLE, X), \
1251 INSN_3(JMP, JSET, X), \
1252 /* Immediate based. */ \
1253 INSN_3(JMP, JEQ, K), \
1254 INSN_3(JMP, JNE, K), \
1255 INSN_3(JMP, JGT, K), \
1256 INSN_3(JMP, JLT, K), \
1257 INSN_3(JMP, JGE, K), \
1258 INSN_3(JMP, JLE, K), \
1259 INSN_3(JMP, JSGT, K), \
1260 INSN_3(JMP, JSLT, K), \
1261 INSN_3(JMP, JSGE, K), \
1262 INSN_3(JMP, JSLE, K), \
1263 INSN_3(JMP, JSET, K), \
1264 INSN_2(JMP, JA), \
1265 /* Store instructions. */ \
1266 /* Register based. */ \
1267 INSN_3(STX, MEM, B), \
1268 INSN_3(STX, MEM, H), \
1269 INSN_3(STX, MEM, W), \
1270 INSN_3(STX, MEM, DW), \
1271 INSN_3(STX, XADD, W), \
1272 INSN_3(STX, XADD, DW), \
1273 /* Immediate based. */ \
1274 INSN_3(ST, MEM, B), \
1275 INSN_3(ST, MEM, H), \
1276 INSN_3(ST, MEM, W), \
1277 INSN_3(ST, MEM, DW), \
1278 /* Load instructions. */ \
1279 /* Register based. */ \
1280 INSN_3(LDX, MEM, B), \
1281 INSN_3(LDX, MEM, H), \
1282 INSN_3(LDX, MEM, W), \
1283 INSN_3(LDX, MEM, DW), \
1284 /* Immediate based. */ \
Daniel Borkmanne0cea7c2018-05-04 01:08:14 +02001285 INSN_3(LD, IMM, DW)
Daniel Borkmann5e581da2018-01-26 23:33:38 +01001286
1287bool bpf_opcode_in_insntable(u8 code)
1288{
1289#define BPF_INSN_2_TBL(x, y) [BPF_##x | BPF_##y] = true
1290#define BPF_INSN_3_TBL(x, y, z) [BPF_##x | BPF_##y | BPF_##z] = true
1291 static const bool public_insntable[256] = {
1292 [0 ... 255] = false,
1293 /* Now overwrite non-defaults ... */
1294 BPF_INSN_MAP(BPF_INSN_2_TBL, BPF_INSN_3_TBL),
Daniel Borkmanne0cea7c2018-05-04 01:08:14 +02001295 /* UAPI exposed, but rewritten opcodes. cBPF carry-over. */
1296 [BPF_LD | BPF_ABS | BPF_B] = true,
1297 [BPF_LD | BPF_ABS | BPF_H] = true,
1298 [BPF_LD | BPF_ABS | BPF_W] = true,
1299 [BPF_LD | BPF_IND | BPF_B] = true,
1300 [BPF_LD | BPF_IND | BPF_H] = true,
1301 [BPF_LD | BPF_IND | BPF_W] = true,
Daniel Borkmann5e581da2018-01-26 23:33:38 +01001302 };
1303#undef BPF_INSN_3_TBL
1304#undef BPF_INSN_2_TBL
1305 return public_insntable[code];
1306}
1307
Alexei Starovoitov290af862018-01-09 10:04:29 -08001308#ifndef CONFIG_BPF_JIT_ALWAYS_ON
Daniel Borkmann6e07a632019-11-02 00:18:00 +01001309u64 __weak bpf_probe_read_kernel(void *dst, u32 size, const void *unsafe_ptr)
Alexei Starovoitov2a027592019-10-15 20:25:02 -07001310{
1311 memset(dst, 0, size);
1312 return -EFAULT;
1313}
Daniel Borkmann6e07a632019-11-02 00:18:00 +01001314
Alexei Starovoitovf5bffec2014-07-22 23:01:58 -07001315/**
Alexei Starovoitov7ae457c2014-07-30 20:34:16 -07001316 * __bpf_prog_run - run eBPF program on a given context
Valdis Kletnieksde1da682019-01-28 23:04:46 -05001317 * @regs: is the array of MAX_BPF_EXT_REG eBPF pseudo-registers
Alexei Starovoitov7ae457c2014-07-30 20:34:16 -07001318 * @insn: is the array of eBPF instructions
Valdis Kletnieksde1da682019-01-28 23:04:46 -05001319 * @stack: is the eBPF storage stack
Alexei Starovoitovf5bffec2014-07-22 23:01:58 -07001320 *
Alexei Starovoitov7ae457c2014-07-30 20:34:16 -07001321 * Decode and execute eBPF instructions.
Alexei Starovoitovf5bffec2014-07-22 23:01:58 -07001322 */
Josh Poimboeuf3193c082019-07-17 20:36:45 -05001323static u64 __no_fgcse ___bpf_prog_run(u64 *regs, const struct bpf_insn *insn, u64 *stack)
Alexei Starovoitovf5bffec2014-07-22 23:01:58 -07001324{
Daniel Borkmann5e581da2018-01-26 23:33:38 +01001325#define BPF_INSN_2_LBL(x, y) [BPF_##x | BPF_##y] = &&x##_##y
1326#define BPF_INSN_3_LBL(x, y, z) [BPF_##x | BPF_##y | BPF_##z] = &&x##_##y##_##z
Josh Poimboeufe55a7322019-06-27 20:50:47 -05001327 static const void * const jumptable[256] __annotate_jump_table = {
Alexei Starovoitovf5bffec2014-07-22 23:01:58 -07001328 [0 ... 255] = &&default_label,
1329 /* Now overwrite non-defaults ... */
Daniel Borkmann5e581da2018-01-26 23:33:38 +01001330 BPF_INSN_MAP(BPF_INSN_2_LBL, BPF_INSN_3_LBL),
1331 /* Non-UAPI available opcodes. */
Alexei Starovoitov1ea47e02017-12-14 17:55:13 -08001332 [BPF_JMP | BPF_CALL_ARGS] = &&JMP_CALL_ARGS,
Alexei Starovoitov71189fa2017-05-30 13:31:27 -07001333 [BPF_JMP | BPF_TAIL_CALL] = &&JMP_TAIL_CALL,
Alexei Starovoitov2a027592019-10-15 20:25:02 -07001334 [BPF_LDX | BPF_PROBE_MEM | BPF_B] = &&LDX_PROBE_MEM_B,
1335 [BPF_LDX | BPF_PROBE_MEM | BPF_H] = &&LDX_PROBE_MEM_H,
1336 [BPF_LDX | BPF_PROBE_MEM | BPF_W] = &&LDX_PROBE_MEM_W,
1337 [BPF_LDX | BPF_PROBE_MEM | BPF_DW] = &&LDX_PROBE_MEM_DW,
Alexei Starovoitovf5bffec2014-07-22 23:01:58 -07001338 };
Daniel Borkmann5e581da2018-01-26 23:33:38 +01001339#undef BPF_INSN_3_LBL
1340#undef BPF_INSN_2_LBL
Alexei Starovoitov04fd61ab2015-05-19 16:59:03 -07001341 u32 tail_call_cnt = 0;
Alexei Starovoitovf5bffec2014-07-22 23:01:58 -07001342
1343#define CONT ({ insn++; goto select_insn; })
1344#define CONT_JMP ({ insn++; goto select_insn; })
1345
Alexei Starovoitovf5bffec2014-07-22 23:01:58 -07001346select_insn:
1347 goto *jumptable[insn->code];
1348
1349 /* ALU */
1350#define ALU(OPCODE, OP) \
1351 ALU64_##OPCODE##_X: \
1352 DST = DST OP SRC; \
1353 CONT; \
1354 ALU_##OPCODE##_X: \
1355 DST = (u32) DST OP (u32) SRC; \
1356 CONT; \
1357 ALU64_##OPCODE##_K: \
1358 DST = DST OP IMM; \
1359 CONT; \
1360 ALU_##OPCODE##_K: \
1361 DST = (u32) DST OP (u32) IMM; \
1362 CONT;
1363
1364 ALU(ADD, +)
1365 ALU(SUB, -)
1366 ALU(AND, &)
1367 ALU(OR, |)
1368 ALU(LSH, <<)
1369 ALU(RSH, >>)
1370 ALU(XOR, ^)
1371 ALU(MUL, *)
1372#undef ALU
1373 ALU_NEG:
1374 DST = (u32) -DST;
1375 CONT;
1376 ALU64_NEG:
1377 DST = -DST;
1378 CONT;
1379 ALU_MOV_X:
1380 DST = (u32) SRC;
1381 CONT;
1382 ALU_MOV_K:
1383 DST = (u32) IMM;
1384 CONT;
1385 ALU64_MOV_X:
1386 DST = SRC;
1387 CONT;
1388 ALU64_MOV_K:
1389 DST = IMM;
1390 CONT;
Alexei Starovoitov02ab6952014-09-04 22:17:17 -07001391 LD_IMM_DW:
1392 DST = (u64) (u32) insn[0].imm | ((u64) (u32) insn[1].imm) << 32;
1393 insn++;
1394 CONT;
Jiong Wang2dc6b102018-12-05 13:52:34 -05001395 ALU_ARSH_X:
Jiong Wang75672dd2019-06-25 17:41:50 +01001396 DST = (u64) (u32) (((s32) DST) >> SRC);
Jiong Wang2dc6b102018-12-05 13:52:34 -05001397 CONT;
1398 ALU_ARSH_K:
Jiong Wang75672dd2019-06-25 17:41:50 +01001399 DST = (u64) (u32) (((s32) DST) >> IMM);
Jiong Wang2dc6b102018-12-05 13:52:34 -05001400 CONT;
Alexei Starovoitovf5bffec2014-07-22 23:01:58 -07001401 ALU64_ARSH_X:
1402 (*(s64 *) &DST) >>= SRC;
1403 CONT;
1404 ALU64_ARSH_K:
1405 (*(s64 *) &DST) >>= IMM;
1406 CONT;
1407 ALU64_MOD_X:
Daniel Borkmann144cd912019-01-03 00:58:28 +01001408 div64_u64_rem(DST, SRC, &AX);
1409 DST = AX;
Alexei Starovoitovf5bffec2014-07-22 23:01:58 -07001410 CONT;
1411 ALU_MOD_X:
Daniel Borkmann144cd912019-01-03 00:58:28 +01001412 AX = (u32) DST;
1413 DST = do_div(AX, (u32) SRC);
Alexei Starovoitovf5bffec2014-07-22 23:01:58 -07001414 CONT;
1415 ALU64_MOD_K:
Daniel Borkmann144cd912019-01-03 00:58:28 +01001416 div64_u64_rem(DST, IMM, &AX);
1417 DST = AX;
Alexei Starovoitovf5bffec2014-07-22 23:01:58 -07001418 CONT;
1419 ALU_MOD_K:
Daniel Borkmann144cd912019-01-03 00:58:28 +01001420 AX = (u32) DST;
1421 DST = do_div(AX, (u32) IMM);
Alexei Starovoitovf5bffec2014-07-22 23:01:58 -07001422 CONT;
1423 ALU64_DIV_X:
Alexei Starovoitov876a7ae2015-04-27 14:40:37 -07001424 DST = div64_u64(DST, SRC);
Alexei Starovoitovf5bffec2014-07-22 23:01:58 -07001425 CONT;
1426 ALU_DIV_X:
Daniel Borkmann144cd912019-01-03 00:58:28 +01001427 AX = (u32) DST;
1428 do_div(AX, (u32) SRC);
1429 DST = (u32) AX;
Alexei Starovoitovf5bffec2014-07-22 23:01:58 -07001430 CONT;
1431 ALU64_DIV_K:
Alexei Starovoitov876a7ae2015-04-27 14:40:37 -07001432 DST = div64_u64(DST, IMM);
Alexei Starovoitovf5bffec2014-07-22 23:01:58 -07001433 CONT;
1434 ALU_DIV_K:
Daniel Borkmann144cd912019-01-03 00:58:28 +01001435 AX = (u32) DST;
1436 do_div(AX, (u32) IMM);
1437 DST = (u32) AX;
Alexei Starovoitovf5bffec2014-07-22 23:01:58 -07001438 CONT;
1439 ALU_END_TO_BE:
1440 switch (IMM) {
1441 case 16:
1442 DST = (__force u16) cpu_to_be16(DST);
1443 break;
1444 case 32:
1445 DST = (__force u32) cpu_to_be32(DST);
1446 break;
1447 case 64:
1448 DST = (__force u64) cpu_to_be64(DST);
1449 break;
1450 }
1451 CONT;
1452 ALU_END_TO_LE:
1453 switch (IMM) {
1454 case 16:
1455 DST = (__force u16) cpu_to_le16(DST);
1456 break;
1457 case 32:
1458 DST = (__force u32) cpu_to_le32(DST);
1459 break;
1460 case 64:
1461 DST = (__force u64) cpu_to_le64(DST);
1462 break;
1463 }
1464 CONT;
1465
1466 /* CALL */
1467 JMP_CALL:
1468 /* Function call scratches BPF_R1-BPF_R5 registers,
1469 * preserves BPF_R6-BPF_R9, and stores return value
1470 * into BPF_R0.
1471 */
1472 BPF_R0 = (__bpf_call_base + insn->imm)(BPF_R1, BPF_R2, BPF_R3,
1473 BPF_R4, BPF_R5);
1474 CONT;
1475
Alexei Starovoitov1ea47e02017-12-14 17:55:13 -08001476 JMP_CALL_ARGS:
1477 BPF_R0 = (__bpf_call_base_args + insn->imm)(BPF_R1, BPF_R2,
1478 BPF_R3, BPF_R4,
1479 BPF_R5,
1480 insn + insn->off + 1);
1481 CONT;
1482
Alexei Starovoitov04fd61ab2015-05-19 16:59:03 -07001483 JMP_TAIL_CALL: {
1484 struct bpf_map *map = (struct bpf_map *) (unsigned long) BPF_R2;
1485 struct bpf_array *array = container_of(map, struct bpf_array, map);
1486 struct bpf_prog *prog;
Alexei Starovoitov90caccd2017-10-03 15:37:20 -07001487 u32 index = BPF_R3;
Alexei Starovoitov04fd61ab2015-05-19 16:59:03 -07001488
1489 if (unlikely(index >= array->map.max_entries))
1490 goto out;
Alexei Starovoitov04fd61ab2015-05-19 16:59:03 -07001491 if (unlikely(tail_call_cnt > MAX_TAIL_CALL_CNT))
1492 goto out;
1493
1494 tail_call_cnt++;
1495
Wang Nan2a36f0b2015-08-06 07:02:33 +00001496 prog = READ_ONCE(array->ptrs[index]);
Daniel Borkmann1ca1cc92016-06-28 12:18:23 +02001497 if (!prog)
Alexei Starovoitov04fd61ab2015-05-19 16:59:03 -07001498 goto out;
1499
Daniel Borkmannc4675f92015-07-13 20:49:32 +02001500 /* ARG1 at this point is guaranteed to point to CTX from
1501 * the verifier side due to the fact that the tail call is
1502 * handeled like a helper, that is, bpf_tail_call_proto,
1503 * where arg1_type is ARG_PTR_TO_CTX.
1504 */
Alexei Starovoitov04fd61ab2015-05-19 16:59:03 -07001505 insn = prog->insnsi;
1506 goto select_insn;
1507out:
1508 CONT;
1509 }
Alexei Starovoitovf5bffec2014-07-22 23:01:58 -07001510 JMP_JA:
1511 insn += insn->off;
1512 CONT;
Alexei Starovoitovf5bffec2014-07-22 23:01:58 -07001513 JMP_EXIT:
1514 return BPF_R0;
Jiong Wang503a8862019-01-26 12:26:04 -05001515 /* JMP */
1516#define COND_JMP(SIGN, OPCODE, CMP_OP) \
1517 JMP_##OPCODE##_X: \
1518 if ((SIGN##64) DST CMP_OP (SIGN##64) SRC) { \
1519 insn += insn->off; \
1520 CONT_JMP; \
1521 } \
1522 CONT; \
1523 JMP32_##OPCODE##_X: \
1524 if ((SIGN##32) DST CMP_OP (SIGN##32) SRC) { \
1525 insn += insn->off; \
1526 CONT_JMP; \
1527 } \
1528 CONT; \
1529 JMP_##OPCODE##_K: \
1530 if ((SIGN##64) DST CMP_OP (SIGN##64) IMM) { \
1531 insn += insn->off; \
1532 CONT_JMP; \
1533 } \
1534 CONT; \
1535 JMP32_##OPCODE##_K: \
1536 if ((SIGN##32) DST CMP_OP (SIGN##32) IMM) { \
1537 insn += insn->off; \
1538 CONT_JMP; \
1539 } \
1540 CONT;
1541 COND_JMP(u, JEQ, ==)
1542 COND_JMP(u, JNE, !=)
1543 COND_JMP(u, JGT, >)
1544 COND_JMP(u, JLT, <)
1545 COND_JMP(u, JGE, >=)
1546 COND_JMP(u, JLE, <=)
1547 COND_JMP(u, JSET, &)
1548 COND_JMP(s, JSGT, >)
1549 COND_JMP(s, JSLT, <)
1550 COND_JMP(s, JSGE, >=)
1551 COND_JMP(s, JSLE, <=)
1552#undef COND_JMP
Alexei Starovoitovf5bffec2014-07-22 23:01:58 -07001553 /* STX and ST and LDX*/
1554#define LDST(SIZEOP, SIZE) \
1555 STX_MEM_##SIZEOP: \
1556 *(SIZE *)(unsigned long) (DST + insn->off) = SRC; \
1557 CONT; \
1558 ST_MEM_##SIZEOP: \
1559 *(SIZE *)(unsigned long) (DST + insn->off) = IMM; \
1560 CONT; \
1561 LDX_MEM_##SIZEOP: \
1562 DST = *(SIZE *)(unsigned long) (SRC + insn->off); \
1563 CONT;
1564
1565 LDST(B, u8)
1566 LDST(H, u16)
1567 LDST(W, u32)
1568 LDST(DW, u64)
1569#undef LDST
Daniel Borkmann6e07a632019-11-02 00:18:00 +01001570#define LDX_PROBE(SIZEOP, SIZE) \
1571 LDX_PROBE_MEM_##SIZEOP: \
1572 bpf_probe_read_kernel(&DST, SIZE, (const void *)(long) SRC); \
Alexei Starovoitov2a027592019-10-15 20:25:02 -07001573 CONT;
1574 LDX_PROBE(B, 1)
1575 LDX_PROBE(H, 2)
1576 LDX_PROBE(W, 4)
1577 LDX_PROBE(DW, 8)
1578#undef LDX_PROBE
1579
Alexei Starovoitovf5bffec2014-07-22 23:01:58 -07001580 STX_XADD_W: /* lock xadd *(u32 *)(dst_reg + off16) += src_reg */
1581 atomic_add((u32) SRC, (atomic_t *)(unsigned long)
1582 (DST + insn->off));
1583 CONT;
1584 STX_XADD_DW: /* lock xadd *(u64 *)(dst_reg + off16) += src_reg */
1585 atomic64_add((u64) SRC, (atomic64_t *)(unsigned long)
1586 (DST + insn->off));
1587 CONT;
Alexei Starovoitovf5bffec2014-07-22 23:01:58 -07001588
1589 default_label:
Daniel Borkmann5e581da2018-01-26 23:33:38 +01001590 /* If we ever reach this, we have a bug somewhere. Die hard here
1591 * instead of just returning 0; we could be somewhere in a subprog,
1592 * so execution could continue otherwise which we do /not/ want.
1593 *
1594 * Note, verifier whitelists all opcodes in bpf_opcode_in_insntable().
1595 */
1596 pr_warn("BPF interpreter: unknown opcode %02x\n", insn->code);
1597 BUG_ON(1);
Alexei Starovoitovf5bffec2014-07-22 23:01:58 -07001598 return 0;
1599}
Alexei Starovoitovf696b8f2017-05-30 13:31:28 -07001600
Alexei Starovoitovb870aa92017-05-30 13:31:33 -07001601#define PROG_NAME(stack_size) __bpf_prog_run##stack_size
1602#define DEFINE_BPF_PROG_RUN(stack_size) \
1603static unsigned int PROG_NAME(stack_size)(const void *ctx, const struct bpf_insn *insn) \
1604{ \
1605 u64 stack[stack_size / sizeof(u64)]; \
Daniel Borkmann144cd912019-01-03 00:58:28 +01001606 u64 regs[MAX_BPF_EXT_REG]; \
Alexei Starovoitovb870aa92017-05-30 13:31:33 -07001607\
1608 FP = (u64) (unsigned long) &stack[ARRAY_SIZE(stack)]; \
1609 ARG1 = (u64) (unsigned long) ctx; \
1610 return ___bpf_prog_run(regs, insn, stack); \
Alexei Starovoitovf696b8f2017-05-30 13:31:28 -07001611}
Alexei Starovoitovf5bffec2014-07-22 23:01:58 -07001612
Alexei Starovoitov1ea47e02017-12-14 17:55:13 -08001613#define PROG_NAME_ARGS(stack_size) __bpf_prog_run_args##stack_size
1614#define DEFINE_BPF_PROG_RUN_ARGS(stack_size) \
1615static u64 PROG_NAME_ARGS(stack_size)(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5, \
1616 const struct bpf_insn *insn) \
1617{ \
1618 u64 stack[stack_size / sizeof(u64)]; \
Daniel Borkmann144cd912019-01-03 00:58:28 +01001619 u64 regs[MAX_BPF_EXT_REG]; \
Alexei Starovoitov1ea47e02017-12-14 17:55:13 -08001620\
1621 FP = (u64) (unsigned long) &stack[ARRAY_SIZE(stack)]; \
1622 BPF_R1 = r1; \
1623 BPF_R2 = r2; \
1624 BPF_R3 = r3; \
1625 BPF_R4 = r4; \
1626 BPF_R5 = r5; \
1627 return ___bpf_prog_run(regs, insn, stack); \
1628}
1629
Alexei Starovoitovb870aa92017-05-30 13:31:33 -07001630#define EVAL1(FN, X) FN(X)
1631#define EVAL2(FN, X, Y...) FN(X) EVAL1(FN, Y)
1632#define EVAL3(FN, X, Y...) FN(X) EVAL2(FN, Y)
1633#define EVAL4(FN, X, Y...) FN(X) EVAL3(FN, Y)
1634#define EVAL5(FN, X, Y...) FN(X) EVAL4(FN, Y)
1635#define EVAL6(FN, X, Y...) FN(X) EVAL5(FN, Y)
1636
1637EVAL6(DEFINE_BPF_PROG_RUN, 32, 64, 96, 128, 160, 192);
1638EVAL6(DEFINE_BPF_PROG_RUN, 224, 256, 288, 320, 352, 384);
1639EVAL4(DEFINE_BPF_PROG_RUN, 416, 448, 480, 512);
1640
Alexei Starovoitov1ea47e02017-12-14 17:55:13 -08001641EVAL6(DEFINE_BPF_PROG_RUN_ARGS, 32, 64, 96, 128, 160, 192);
1642EVAL6(DEFINE_BPF_PROG_RUN_ARGS, 224, 256, 288, 320, 352, 384);
1643EVAL4(DEFINE_BPF_PROG_RUN_ARGS, 416, 448, 480, 512);
1644
Alexei Starovoitovb870aa92017-05-30 13:31:33 -07001645#define PROG_NAME_LIST(stack_size) PROG_NAME(stack_size),
1646
1647static unsigned int (*interpreters[])(const void *ctx,
1648 const struct bpf_insn *insn) = {
1649EVAL6(PROG_NAME_LIST, 32, 64, 96, 128, 160, 192)
1650EVAL6(PROG_NAME_LIST, 224, 256, 288, 320, 352, 384)
1651EVAL4(PROG_NAME_LIST, 416, 448, 480, 512)
1652};
Alexei Starovoitov1ea47e02017-12-14 17:55:13 -08001653#undef PROG_NAME_LIST
1654#define PROG_NAME_LIST(stack_size) PROG_NAME_ARGS(stack_size),
1655static u64 (*interpreters_args[])(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5,
1656 const struct bpf_insn *insn) = {
1657EVAL6(PROG_NAME_LIST, 32, 64, 96, 128, 160, 192)
1658EVAL6(PROG_NAME_LIST, 224, 256, 288, 320, 352, 384)
1659EVAL4(PROG_NAME_LIST, 416, 448, 480, 512)
1660};
1661#undef PROG_NAME_LIST
1662
1663void bpf_patch_call_args(struct bpf_insn *insn, u32 stack_depth)
1664{
1665 stack_depth = max_t(u32, stack_depth, 1);
1666 insn->off = (s16) insn->imm;
1667 insn->imm = interpreters_args[(round_up(stack_depth, 32) / 32) - 1] -
1668 __bpf_call_base_args;
1669 insn->code = BPF_JMP | BPF_CALL_ARGS;
1670}
Alexei Starovoitovb870aa92017-05-30 13:31:33 -07001671
Alexei Starovoitov290af862018-01-09 10:04:29 -08001672#else
Daniel Borkmannfa9dd592018-01-20 01:24:33 +01001673static unsigned int __bpf_prog_ret0_warn(const void *ctx,
1674 const struct bpf_insn *insn)
Alexei Starovoitov290af862018-01-09 10:04:29 -08001675{
Daniel Borkmannfa9dd592018-01-20 01:24:33 +01001676 /* If this handler ever gets executed, then BPF_JIT_ALWAYS_ON
1677 * is not working properly, so warn about it!
1678 */
1679 WARN_ON_ONCE(1);
Alexei Starovoitov290af862018-01-09 10:04:29 -08001680 return 0;
1681}
1682#endif
1683
Daniel Borkmann3324b582015-05-29 23:23:07 +02001684bool bpf_prog_array_compatible(struct bpf_array *array,
1685 const struct bpf_prog *fp)
Alexei Starovoitovf5bffec2014-07-22 23:01:58 -07001686{
Josef Bacik9802d862017-12-11 11:36:48 -05001687 if (fp->kprobe_override)
1688 return false;
1689
Daniel Borkmann3324b582015-05-29 23:23:07 +02001690 if (!array->owner_prog_type) {
1691 /* There's no owner yet where we could check for
1692 * compatibility.
1693 */
Alexei Starovoitov04fd61ab2015-05-19 16:59:03 -07001694 array->owner_prog_type = fp->type;
1695 array->owner_jited = fp->jited;
Daniel Borkmann3324b582015-05-29 23:23:07 +02001696
1697 return true;
Alexei Starovoitov04fd61ab2015-05-19 16:59:03 -07001698 }
Daniel Borkmann3324b582015-05-29 23:23:07 +02001699
1700 return array->owner_prog_type == fp->type &&
1701 array->owner_jited == fp->jited;
Alexei Starovoitov04fd61ab2015-05-19 16:59:03 -07001702}
1703
Daniel Borkmann3324b582015-05-29 23:23:07 +02001704static int bpf_check_tail_call(const struct bpf_prog *fp)
Alexei Starovoitov04fd61ab2015-05-19 16:59:03 -07001705{
1706 struct bpf_prog_aux *aux = fp->aux;
1707 int i;
1708
1709 for (i = 0; i < aux->used_map_cnt; i++) {
Daniel Borkmann3324b582015-05-29 23:23:07 +02001710 struct bpf_map *map = aux->used_maps[i];
Alexei Starovoitov04fd61ab2015-05-19 16:59:03 -07001711 struct bpf_array *array;
Alexei Starovoitov04fd61ab2015-05-19 16:59:03 -07001712
Alexei Starovoitov04fd61ab2015-05-19 16:59:03 -07001713 if (map->map_type != BPF_MAP_TYPE_PROG_ARRAY)
1714 continue;
Daniel Borkmann3324b582015-05-29 23:23:07 +02001715
Alexei Starovoitov04fd61ab2015-05-19 16:59:03 -07001716 array = container_of(map, struct bpf_array, map);
1717 if (!bpf_prog_array_compatible(array, fp))
1718 return -EINVAL;
1719 }
1720
1721 return 0;
1722}
1723
Daniel Borkmann9facc332018-06-15 02:30:48 +02001724static void bpf_prog_select_func(struct bpf_prog *fp)
1725{
1726#ifndef CONFIG_BPF_JIT_ALWAYS_ON
1727 u32 stack_depth = max_t(u32, fp->aux->stack_depth, 1);
1728
1729 fp->bpf_func = interpreters[(round_up(stack_depth, 32) / 32) - 1];
1730#else
1731 fp->bpf_func = __bpf_prog_ret0_warn;
1732#endif
1733}
1734
Alexei Starovoitovf5bffec2014-07-22 23:01:58 -07001735/**
Daniel Borkmann3324b582015-05-29 23:23:07 +02001736 * bpf_prog_select_runtime - select exec runtime for BPF program
Alexei Starovoitov7ae457c2014-07-30 20:34:16 -07001737 * @fp: bpf_prog populated with internal BPF program
Daniel Borkmannd1c55ab2016-05-13 19:08:31 +02001738 * @err: pointer to error variable
Alexei Starovoitovf5bffec2014-07-22 23:01:58 -07001739 *
Daniel Borkmann3324b582015-05-29 23:23:07 +02001740 * Try to JIT eBPF program, if JIT is not available, use interpreter.
1741 * The BPF program will be executed via BPF_PROG_RUN() macro.
Alexei Starovoitovf5bffec2014-07-22 23:01:58 -07001742 */
Daniel Borkmannd1c55ab2016-05-13 19:08:31 +02001743struct bpf_prog *bpf_prog_select_runtime(struct bpf_prog *fp, int *err)
Alexei Starovoitovf5bffec2014-07-22 23:01:58 -07001744{
Daniel Borkmann9facc332018-06-15 02:30:48 +02001745 /* In case of BPF to BPF calls, verifier did all the prep
1746 * work with regards to JITing, etc.
1747 */
1748 if (fp->bpf_func)
1749 goto finalize;
Martin KaFai Lau8007e402017-06-28 10:41:24 -07001750
Daniel Borkmann9facc332018-06-15 02:30:48 +02001751 bpf_prog_select_func(fp);
Alexei Starovoitovf5bffec2014-07-22 23:01:58 -07001752
Daniel Borkmannd1c55ab2016-05-13 19:08:31 +02001753 /* eBPF JITs can rewrite the program in case constant
1754 * blinding is active. However, in case of error during
1755 * blinding, bpf_int_jit_compile() must always return a
1756 * valid program, which in this case would simply not
1757 * be JITed, but falls back to the interpreter.
1758 */
Jakub Kicinskiab3f0062017-11-03 13:56:17 -07001759 if (!bpf_prog_is_dev_bound(fp->aux)) {
Martin KaFai Lauc454a462018-12-07 16:42:25 -08001760 *err = bpf_prog_alloc_jited_linfo(fp);
1761 if (*err)
1762 return fp;
1763
Jakub Kicinskiab3f0062017-11-03 13:56:17 -07001764 fp = bpf_int_jit_compile(fp);
Alexei Starovoitov290af862018-01-09 10:04:29 -08001765 if (!fp->jited) {
Martin KaFai Lauc454a462018-12-07 16:42:25 -08001766 bpf_prog_free_jited_linfo(fp);
1767#ifdef CONFIG_BPF_JIT_ALWAYS_ON
Alexei Starovoitov290af862018-01-09 10:04:29 -08001768 *err = -ENOTSUPP;
1769 return fp;
Alexei Starovoitov290af862018-01-09 10:04:29 -08001770#endif
Martin KaFai Lauc454a462018-12-07 16:42:25 -08001771 } else {
1772 bpf_prog_free_unused_jited_linfo(fp);
1773 }
Jakub Kicinskiab3f0062017-11-03 13:56:17 -07001774 } else {
1775 *err = bpf_prog_offload_compile(fp);
1776 if (*err)
1777 return fp;
1778 }
Daniel Borkmann9facc332018-06-15 02:30:48 +02001779
1780finalize:
Daniel Borkmann60a3b222014-09-02 22:53:44 +02001781 bpf_prog_lock_ro(fp);
Alexei Starovoitov04fd61ab2015-05-19 16:59:03 -07001782
Daniel Borkmann3324b582015-05-29 23:23:07 +02001783 /* The tail call compatibility check can only be done at
1784 * this late stage as we need to determine, if we deal
1785 * with JITed or non JITed program concatenations and not
1786 * all eBPF JITs might immediately support all features.
1787 */
Daniel Borkmannd1c55ab2016-05-13 19:08:31 +02001788 *err = bpf_check_tail_call(fp);
1789
1790 return fp;
Alexei Starovoitovf5bffec2014-07-22 23:01:58 -07001791}
Alexei Starovoitov7ae457c2014-07-30 20:34:16 -07001792EXPORT_SYMBOL_GPL(bpf_prog_select_runtime);
Alexei Starovoitovf5bffec2014-07-22 23:01:58 -07001793
Yonghong Songe87c6bc2017-10-23 23:53:08 -07001794static unsigned int __bpf_prog_ret1(const void *ctx,
1795 const struct bpf_insn *insn)
1796{
1797 return 1;
1798}
1799
1800static struct bpf_prog_dummy {
1801 struct bpf_prog prog;
1802} dummy_bpf_prog = {
1803 .prog = {
1804 .bpf_func = __bpf_prog_ret1,
1805 },
1806};
1807
Alexei Starovoitov324bda9e62017-10-02 22:50:21 -07001808/* to avoid allocating empty bpf_prog_array for cgroups that
1809 * don't have bpf program attached use one global 'empty_prog_array'
1810 * It will not be modified the caller of bpf_prog_array_alloc()
1811 * (since caller requested prog_cnt == 0)
1812 * that pointer should be 'freed' by bpf_prog_array_free()
1813 */
1814static struct {
1815 struct bpf_prog_array hdr;
1816 struct bpf_prog *null_prog;
1817} empty_prog_array = {
1818 .null_prog = NULL,
1819};
1820
Roman Gushchind29ab6e2018-07-13 12:41:10 -07001821struct bpf_prog_array *bpf_prog_array_alloc(u32 prog_cnt, gfp_t flags)
Alexei Starovoitov324bda9e62017-10-02 22:50:21 -07001822{
1823 if (prog_cnt)
1824 return kzalloc(sizeof(struct bpf_prog_array) +
Roman Gushchin394e40a2018-08-02 14:27:21 -07001825 sizeof(struct bpf_prog_array_item) *
1826 (prog_cnt + 1),
Alexei Starovoitov324bda9e62017-10-02 22:50:21 -07001827 flags);
1828
1829 return &empty_prog_array.hdr;
1830}
1831
Stanislav Fomichev54e9c9d2019-05-28 14:14:41 -07001832void bpf_prog_array_free(struct bpf_prog_array *progs)
Alexei Starovoitov324bda9e62017-10-02 22:50:21 -07001833{
Stanislav Fomichev54e9c9d2019-05-28 14:14:41 -07001834 if (!progs || progs == &empty_prog_array.hdr)
Alexei Starovoitov324bda9e62017-10-02 22:50:21 -07001835 return;
1836 kfree_rcu(progs, rcu);
1837}
1838
Stanislav Fomichev54e9c9d2019-05-28 14:14:41 -07001839int bpf_prog_array_length(struct bpf_prog_array *array)
Alexei Starovoitov468e2f62017-10-02 22:50:22 -07001840{
Roman Gushchin394e40a2018-08-02 14:27:21 -07001841 struct bpf_prog_array_item *item;
Alexei Starovoitov468e2f62017-10-02 22:50:22 -07001842 u32 cnt = 0;
1843
Stanislav Fomichev54e9c9d2019-05-28 14:14:41 -07001844 for (item = array->items; item->prog; item++)
Roman Gushchin394e40a2018-08-02 14:27:21 -07001845 if (item->prog != &dummy_bpf_prog.prog)
Yonghong Songc8c088b2017-11-30 13:47:54 -08001846 cnt++;
Alexei Starovoitov468e2f62017-10-02 22:50:22 -07001847 return cnt;
1848}
1849
Stanislav Fomichev0d01da62019-06-27 13:38:47 -07001850bool bpf_prog_array_is_empty(struct bpf_prog_array *array)
1851{
1852 struct bpf_prog_array_item *item;
1853
1854 for (item = array->items; item->prog; item++)
1855 if (item->prog != &dummy_bpf_prog.prog)
1856 return false;
1857 return true;
1858}
Roman Gushchin394e40a2018-08-02 14:27:21 -07001859
Stanislav Fomichev54e9c9d2019-05-28 14:14:41 -07001860static bool bpf_prog_array_copy_core(struct bpf_prog_array *array,
Yonghong Song3a38bb92018-04-10 09:37:32 -07001861 u32 *prog_ids,
1862 u32 request_cnt)
1863{
Roman Gushchin394e40a2018-08-02 14:27:21 -07001864 struct bpf_prog_array_item *item;
Yonghong Song3a38bb92018-04-10 09:37:32 -07001865 int i = 0;
1866
Stanislav Fomichev54e9c9d2019-05-28 14:14:41 -07001867 for (item = array->items; item->prog; item++) {
Roman Gushchin394e40a2018-08-02 14:27:21 -07001868 if (item->prog == &dummy_bpf_prog.prog)
Yonghong Song3a38bb92018-04-10 09:37:32 -07001869 continue;
Roman Gushchin394e40a2018-08-02 14:27:21 -07001870 prog_ids[i] = item->prog->aux->id;
Yonghong Song3a38bb92018-04-10 09:37:32 -07001871 if (++i == request_cnt) {
Roman Gushchin394e40a2018-08-02 14:27:21 -07001872 item++;
Yonghong Song3a38bb92018-04-10 09:37:32 -07001873 break;
1874 }
1875 }
1876
Roman Gushchin394e40a2018-08-02 14:27:21 -07001877 return !!(item->prog);
Yonghong Song3a38bb92018-04-10 09:37:32 -07001878}
1879
Stanislav Fomichev54e9c9d2019-05-28 14:14:41 -07001880int bpf_prog_array_copy_to_user(struct bpf_prog_array *array,
Alexei Starovoitov468e2f62017-10-02 22:50:22 -07001881 __u32 __user *prog_ids, u32 cnt)
1882{
Alexei Starovoitov09112872018-02-02 15:14:05 -08001883 unsigned long err = 0;
Alexei Starovoitov09112872018-02-02 15:14:05 -08001884 bool nospc;
Yonghong Song3a38bb92018-04-10 09:37:32 -07001885 u32 *ids;
Alexei Starovoitov468e2f62017-10-02 22:50:22 -07001886
Alexei Starovoitov09112872018-02-02 15:14:05 -08001887 /* users of this function are doing:
1888 * cnt = bpf_prog_array_length();
1889 * if (cnt > 0)
1890 * bpf_prog_array_copy_to_user(..., cnt);
Stanislav Fomichev54e9c9d2019-05-28 14:14:41 -07001891 * so below kcalloc doesn't need extra cnt > 0 check.
Alexei Starovoitov09112872018-02-02 15:14:05 -08001892 */
Daniel Borkmann9c481b92018-02-14 15:31:00 +01001893 ids = kcalloc(cnt, sizeof(u32), GFP_USER | __GFP_NOWARN);
Alexei Starovoitov09112872018-02-02 15:14:05 -08001894 if (!ids)
1895 return -ENOMEM;
Roman Gushchin394e40a2018-08-02 14:27:21 -07001896 nospc = bpf_prog_array_copy_core(array, ids, cnt);
Alexei Starovoitov09112872018-02-02 15:14:05 -08001897 err = copy_to_user(prog_ids, ids, cnt * sizeof(u32));
1898 kfree(ids);
1899 if (err)
1900 return -EFAULT;
1901 if (nospc)
Alexei Starovoitov468e2f62017-10-02 22:50:22 -07001902 return -ENOSPC;
1903 return 0;
1904}
1905
Stanislav Fomichev54e9c9d2019-05-28 14:14:41 -07001906void bpf_prog_array_delete_safe(struct bpf_prog_array *array,
Yonghong Songe87c6bc2017-10-23 23:53:08 -07001907 struct bpf_prog *old_prog)
1908{
Stanislav Fomichev54e9c9d2019-05-28 14:14:41 -07001909 struct bpf_prog_array_item *item;
Yonghong Songe87c6bc2017-10-23 23:53:08 -07001910
Stanislav Fomichev54e9c9d2019-05-28 14:14:41 -07001911 for (item = array->items; item->prog; item++)
Roman Gushchin394e40a2018-08-02 14:27:21 -07001912 if (item->prog == old_prog) {
1913 WRITE_ONCE(item->prog, &dummy_bpf_prog.prog);
Yonghong Songe87c6bc2017-10-23 23:53:08 -07001914 break;
1915 }
1916}
1917
Stanislav Fomichev54e9c9d2019-05-28 14:14:41 -07001918int bpf_prog_array_copy(struct bpf_prog_array *old_array,
Yonghong Songe87c6bc2017-10-23 23:53:08 -07001919 struct bpf_prog *exclude_prog,
1920 struct bpf_prog *include_prog,
1921 struct bpf_prog_array **new_array)
1922{
1923 int new_prog_cnt, carry_prog_cnt = 0;
Roman Gushchin394e40a2018-08-02 14:27:21 -07001924 struct bpf_prog_array_item *existing;
Yonghong Songe87c6bc2017-10-23 23:53:08 -07001925 struct bpf_prog_array *array;
Sean Young170a7e32018-05-27 12:24:08 +01001926 bool found_exclude = false;
Yonghong Songe87c6bc2017-10-23 23:53:08 -07001927 int new_prog_idx = 0;
1928
1929 /* Figure out how many existing progs we need to carry over to
1930 * the new array.
1931 */
1932 if (old_array) {
Roman Gushchin394e40a2018-08-02 14:27:21 -07001933 existing = old_array->items;
1934 for (; existing->prog; existing++) {
1935 if (existing->prog == exclude_prog) {
Sean Young170a7e32018-05-27 12:24:08 +01001936 found_exclude = true;
1937 continue;
1938 }
Roman Gushchin394e40a2018-08-02 14:27:21 -07001939 if (existing->prog != &dummy_bpf_prog.prog)
Yonghong Songe87c6bc2017-10-23 23:53:08 -07001940 carry_prog_cnt++;
Roman Gushchin394e40a2018-08-02 14:27:21 -07001941 if (existing->prog == include_prog)
Yonghong Songe87c6bc2017-10-23 23:53:08 -07001942 return -EEXIST;
1943 }
1944 }
1945
Sean Young170a7e32018-05-27 12:24:08 +01001946 if (exclude_prog && !found_exclude)
1947 return -ENOENT;
1948
Yonghong Songe87c6bc2017-10-23 23:53:08 -07001949 /* How many progs (not NULL) will be in the new array? */
1950 new_prog_cnt = carry_prog_cnt;
1951 if (include_prog)
1952 new_prog_cnt += 1;
1953
1954 /* Do we have any prog (not NULL) in the new array? */
1955 if (!new_prog_cnt) {
1956 *new_array = NULL;
1957 return 0;
1958 }
1959
1960 /* +1 as the end of prog_array is marked with NULL */
1961 array = bpf_prog_array_alloc(new_prog_cnt + 1, GFP_KERNEL);
1962 if (!array)
1963 return -ENOMEM;
1964
1965 /* Fill in the new prog array */
1966 if (carry_prog_cnt) {
Roman Gushchin394e40a2018-08-02 14:27:21 -07001967 existing = old_array->items;
1968 for (; existing->prog; existing++)
1969 if (existing->prog != exclude_prog &&
1970 existing->prog != &dummy_bpf_prog.prog) {
1971 array->items[new_prog_idx++].prog =
1972 existing->prog;
1973 }
Yonghong Songe87c6bc2017-10-23 23:53:08 -07001974 }
1975 if (include_prog)
Roman Gushchin394e40a2018-08-02 14:27:21 -07001976 array->items[new_prog_idx++].prog = include_prog;
1977 array->items[new_prog_idx].prog = NULL;
Yonghong Songe87c6bc2017-10-23 23:53:08 -07001978 *new_array = array;
1979 return 0;
1980}
1981
Stanislav Fomichev54e9c9d2019-05-28 14:14:41 -07001982int bpf_prog_array_copy_info(struct bpf_prog_array *array,
Yonghong Song3a38bb92018-04-10 09:37:32 -07001983 u32 *prog_ids, u32 request_cnt,
1984 u32 *prog_cnt)
Yonghong Songf371b302017-12-11 11:39:02 -08001985{
1986 u32 cnt = 0;
1987
1988 if (array)
1989 cnt = bpf_prog_array_length(array);
1990
Yonghong Song3a38bb92018-04-10 09:37:32 -07001991 *prog_cnt = cnt;
Yonghong Songf371b302017-12-11 11:39:02 -08001992
1993 /* return early if user requested only program count or nothing to copy */
1994 if (!request_cnt || !cnt)
1995 return 0;
1996
Yonghong Song3a38bb92018-04-10 09:37:32 -07001997 /* this function is called under trace/bpf_trace.c: bpf_event_mutex */
Roman Gushchin394e40a2018-08-02 14:27:21 -07001998 return bpf_prog_array_copy_core(array, prog_ids, request_cnt) ? -ENOSPC
Yonghong Song3a38bb92018-04-10 09:37:32 -07001999 : 0;
Yonghong Songf371b302017-12-11 11:39:02 -08002000}
2001
Daniel Borkmann60a3b222014-09-02 22:53:44 +02002002static void bpf_prog_free_deferred(struct work_struct *work)
2003{
Alexei Starovoitov09756af2014-09-26 00:17:00 -07002004 struct bpf_prog_aux *aux;
Alexei Starovoitov1c2a0882017-12-14 17:55:15 -08002005 int i;
Daniel Borkmann60a3b222014-09-02 22:53:44 +02002006
Alexei Starovoitov09756af2014-09-26 00:17:00 -07002007 aux = container_of(work, struct bpf_prog_aux, work);
Jakub Kicinskiab3f0062017-11-03 13:56:17 -07002008 if (bpf_prog_is_dev_bound(aux))
2009 bpf_prog_offload_destroy(aux->prog);
Yonghong Songc195651e2018-04-28 22:28:08 -07002010#ifdef CONFIG_PERF_EVENTS
2011 if (aux->prog->has_callchain_buf)
2012 put_callchain_buffers();
2013#endif
Alexei Starovoitov1c2a0882017-12-14 17:55:15 -08002014 for (i = 0; i < aux->func_cnt; i++)
2015 bpf_jit_free(aux->func[i]);
2016 if (aux->func_cnt) {
2017 kfree(aux->func);
2018 bpf_prog_unlock_free(aux->prog);
2019 } else {
2020 bpf_jit_free(aux->prog);
2021 }
Daniel Borkmann60a3b222014-09-02 22:53:44 +02002022}
2023
2024/* Free internal BPF program */
Alexei Starovoitov7ae457c2014-07-30 20:34:16 -07002025void bpf_prog_free(struct bpf_prog *fp)
Alexei Starovoitovf5bffec2014-07-22 23:01:58 -07002026{
Alexei Starovoitov09756af2014-09-26 00:17:00 -07002027 struct bpf_prog_aux *aux = fp->aux;
Daniel Borkmann60a3b222014-09-02 22:53:44 +02002028
Alexei Starovoitov09756af2014-09-26 00:17:00 -07002029 INIT_WORK(&aux->work, bpf_prog_free_deferred);
Alexei Starovoitov09756af2014-09-26 00:17:00 -07002030 schedule_work(&aux->work);
Alexei Starovoitovf5bffec2014-07-22 23:01:58 -07002031}
Alexei Starovoitov7ae457c2014-07-30 20:34:16 -07002032EXPORT_SYMBOL_GPL(bpf_prog_free);
Alexei Starovoitovf89b7752014-10-23 18:41:08 -07002033
Daniel Borkmann3ad00402015-10-08 01:20:39 +02002034/* RNG for unpriviledged user space with separated state from prandom_u32(). */
2035static DEFINE_PER_CPU(struct rnd_state, bpf_user_rnd_state);
2036
2037void bpf_user_rnd_init_once(void)
2038{
2039 prandom_init_once(&bpf_user_rnd_state);
2040}
2041
Daniel Borkmannf3694e02016-09-09 02:45:31 +02002042BPF_CALL_0(bpf_user_rnd_u32)
Daniel Borkmann3ad00402015-10-08 01:20:39 +02002043{
2044 /* Should someone ever have the rather unwise idea to use some
2045 * of the registers passed into this function, then note that
2046 * this function is called from native eBPF and classic-to-eBPF
2047 * transformations. Register assignments from both sides are
2048 * different, f.e. classic always sets fn(ctx, A, X) here.
2049 */
2050 struct rnd_state *state;
2051 u32 res;
2052
2053 state = &get_cpu_var(bpf_user_rnd_state);
2054 res = prandom_u32_state(state);
Shaohua Lib761fe22016-09-27 08:42:41 -07002055 put_cpu_var(bpf_user_rnd_state);
Daniel Borkmann3ad00402015-10-08 01:20:39 +02002056
2057 return res;
2058}
2059
Daniel Borkmann3ba67da2015-03-05 23:27:51 +01002060/* Weak definitions of helper functions in case we don't have bpf syscall. */
2061const struct bpf_func_proto bpf_map_lookup_elem_proto __weak;
2062const struct bpf_func_proto bpf_map_update_elem_proto __weak;
2063const struct bpf_func_proto bpf_map_delete_elem_proto __weak;
Mauricio Vasquez Bf1a2e442018-10-18 15:16:25 +02002064const struct bpf_func_proto bpf_map_push_elem_proto __weak;
2065const struct bpf_func_proto bpf_map_pop_elem_proto __weak;
2066const struct bpf_func_proto bpf_map_peek_elem_proto __weak;
Alexei Starovoitovd83525c2019-01-31 15:40:04 -08002067const struct bpf_func_proto bpf_spin_lock_proto __weak;
2068const struct bpf_func_proto bpf_spin_unlock_proto __weak;
Daniel Borkmann3ba67da2015-03-05 23:27:51 +01002069
Daniel Borkmann03e69b52015-03-14 02:27:16 +01002070const struct bpf_func_proto bpf_get_prandom_u32_proto __weak;
Daniel Borkmannc04167c2015-03-14 02:27:17 +01002071const struct bpf_func_proto bpf_get_smp_processor_id_proto __weak;
Daniel Borkmann2d0e30c2016-10-21 12:46:33 +02002072const struct bpf_func_proto bpf_get_numa_node_id_proto __weak;
Daniel Borkmann17ca8cb2015-05-29 23:23:06 +02002073const struct bpf_func_proto bpf_ktime_get_ns_proto __weak;
Daniel Borkmannbd570ff2016-04-18 21:01:24 +02002074
Alexei Starovoitovffeedaf2015-06-12 19:39:12 -07002075const struct bpf_func_proto bpf_get_current_pid_tgid_proto __weak;
2076const struct bpf_func_proto bpf_get_current_uid_gid_proto __weak;
2077const struct bpf_func_proto bpf_get_current_comm_proto __weak;
Yonghong Songbf6fa2c82018-06-03 15:59:41 -07002078const struct bpf_func_proto bpf_get_current_cgroup_id_proto __weak;
Roman Gushchincd339432018-08-02 14:27:24 -07002079const struct bpf_func_proto bpf_get_local_storage_proto __weak;
Daniel Borkmannbd570ff2016-04-18 21:01:24 +02002080
Alexei Starovoitov0756ea32015-06-12 19:39:13 -07002081const struct bpf_func_proto * __weak bpf_get_trace_printk_proto(void)
2082{
2083 return NULL;
2084}
Daniel Borkmann03e69b52015-03-14 02:27:16 +01002085
Daniel Borkmann555c8a82016-07-14 18:08:05 +02002086u64 __weak
2087bpf_event_output(struct bpf_map *map, u64 flags, void *meta, u64 meta_size,
2088 void *ctx, u64 ctx_size, bpf_ctx_copy_t ctx_copy)
Daniel Borkmannbd570ff2016-04-18 21:01:24 +02002089{
Daniel Borkmann555c8a82016-07-14 18:08:05 +02002090 return -ENOTSUPP;
Daniel Borkmannbd570ff2016-04-18 21:01:24 +02002091}
Jakub Kicinski6cb5fb32018-05-03 18:37:10 -07002092EXPORT_SYMBOL_GPL(bpf_event_output);
Daniel Borkmannbd570ff2016-04-18 21:01:24 +02002093
Daniel Borkmann3324b582015-05-29 23:23:07 +02002094/* Always built-in helper functions. */
2095const struct bpf_func_proto bpf_tail_call_proto = {
2096 .func = NULL,
2097 .gpl_only = false,
2098 .ret_type = RET_VOID,
2099 .arg1_type = ARG_PTR_TO_CTX,
2100 .arg2_type = ARG_CONST_MAP_PTR,
2101 .arg3_type = ARG_ANYTHING,
2102};
2103
Daniel Borkmann93831912017-02-16 22:24:49 +01002104/* Stub for JITs that only support cBPF. eBPF programs are interpreted.
2105 * It is encouraged to implement bpf_int_jit_compile() instead, so that
2106 * eBPF and implicitly also cBPF can get JITed!
2107 */
Daniel Borkmannd1c55ab2016-05-13 19:08:31 +02002108struct bpf_prog * __weak bpf_int_jit_compile(struct bpf_prog *prog)
Daniel Borkmann3324b582015-05-29 23:23:07 +02002109{
Daniel Borkmannd1c55ab2016-05-13 19:08:31 +02002110 return prog;
Daniel Borkmann3324b582015-05-29 23:23:07 +02002111}
2112
Daniel Borkmann93831912017-02-16 22:24:49 +01002113/* Stub for JITs that support eBPF. All cBPF code gets transformed into
2114 * eBPF by the kernel and is later compiled by bpf_int_jit_compile().
2115 */
2116void __weak bpf_jit_compile(struct bpf_prog *prog)
2117{
2118}
2119
Martin KaFai Lau17bedab2016-12-07 15:53:11 -08002120bool __weak bpf_helper_changes_pkt_data(void *func)
Alexei Starovoitov969bf052016-05-05 19:49:10 -07002121{
2122 return false;
2123}
2124
Jiong Wanga4b1d3c2019-05-24 23:25:15 +01002125/* Return TRUE if the JIT backend wants verifier to enable sub-register usage
2126 * analysis code and wants explicit zero extension inserted by verifier.
2127 * Otherwise, return FALSE.
2128 */
2129bool __weak bpf_jit_needs_zext(void)
2130{
2131 return false;
2132}
2133
Alexei Starovoitovf89b7752014-10-23 18:41:08 -07002134/* To execute LD_ABS/LD_IND instructions __bpf_prog_run() may call
2135 * skb_copy_bits(), so provide a weak definition of it for NET-less config.
2136 */
2137int __weak skb_copy_bits(const struct sk_buff *skb, int offset, void *to,
2138 int len)
2139{
2140 return -EFAULT;
2141}
Daniel Borkmanna67edbf2017-01-25 02:28:18 +01002142
Alexei Starovoitov492ecee2019-02-25 14:28:39 -08002143DEFINE_STATIC_KEY_FALSE(bpf_stats_enabled_key);
2144EXPORT_SYMBOL(bpf_stats_enabled_key);
Alexei Starovoitov492ecee2019-02-25 14:28:39 -08002145
Daniel Borkmanna67edbf2017-01-25 02:28:18 +01002146/* All definitions of tracepoints related to BPF. */
2147#define CREATE_TRACE_POINTS
2148#include <linux/bpf_trace.h>
2149
2150EXPORT_TRACEPOINT_SYMBOL_GPL(xdp_exception);
Toshiaki Makitae7d47982019-06-13 18:39:58 +09002151EXPORT_TRACEPOINT_SYMBOL_GPL(xdp_bulk_tx);