2 * Linux Socket Filter - Kernel level socket filtering
4 * Based on the design of the Berkeley Packet Filter. The new
5 * internal format has been designed by PLUMgrid:
7 * Copyright (c) 2011 - 2014 PLUMgrid, http://plumgrid.com
11 * Jay Schulist <jschlst@samba.org>
12 * Alexei Starovoitov <ast@plumgrid.com>
13 * Daniel Borkmann <dborkman@redhat.com>
15 * This program is free software; you can redistribute it and/or
16 * modify it under the terms of the GNU General Public License
17 * as published by the Free Software Foundation; either version
18 * 2 of the License, or (at your option) any later version.
20 * Andi Kleen - Fix a few bad bugs and races.
21 * Kris Katterjohn - Added many additional checks in bpf_check_classic()
24 #include <linux/filter.h>
25 #include <linux/skbuff.h>
26 #include <linux/vmalloc.h>
27 #include <linux/random.h>
28 #include <linux/moduleloader.h>
29 #include <linux/bpf.h>
31 #include <asm/unaligned.h>
34 #define BPF_R0 regs[BPF_REG_0]
35 #define BPF_R1 regs[BPF_REG_1]
36 #define BPF_R2 regs[BPF_REG_2]
37 #define BPF_R3 regs[BPF_REG_3]
38 #define BPF_R4 regs[BPF_REG_4]
39 #define BPF_R5 regs[BPF_REG_5]
40 #define BPF_R6 regs[BPF_REG_6]
41 #define BPF_R7 regs[BPF_REG_7]
42 #define BPF_R8 regs[BPF_REG_8]
43 #define BPF_R9 regs[BPF_REG_9]
44 #define BPF_R10 regs[BPF_REG_10]
47 #define DST regs[insn->dst_reg]
48 #define SRC regs[insn->src_reg]
49 #define FP regs[BPF_REG_FP]
50 #define ARG1 regs[BPF_REG_ARG1]
51 #define CTX regs[BPF_REG_CTX]
54 /* No hurry in this branch
56 * Exported for the bpf jit load helper.
58 void *bpf_internal_load_pointer_neg_helper(const struct sk_buff *skb, int k, unsigned int size)
63 ptr = skb_network_header(skb) + k - SKF_NET_OFF;
64 else if (k >= SKF_LL_OFF)
65 ptr = skb_mac_header(skb) + k - SKF_LL_OFF;
67 if (ptr >= skb->head && ptr + size <= skb_tail_pointer(skb))
73 struct bpf_prog *bpf_prog_alloc(unsigned int size, gfp_t gfp_extra_flags)
75 gfp_t gfp_flags = GFP_KERNEL | __GFP_HIGHMEM | __GFP_ZERO |
77 struct bpf_prog_aux *aux;
80 size = round_up(size, PAGE_SIZE);
81 fp = __vmalloc(size, gfp_flags, PAGE_KERNEL);
85 kmemcheck_annotate_bitfield(fp, meta);
87 aux = kzalloc(sizeof(*aux), GFP_KERNEL | gfp_extra_flags);
93 fp->pages = size / PAGE_SIZE;
98 EXPORT_SYMBOL_GPL(bpf_prog_alloc);
100 struct bpf_prog *bpf_prog_realloc(struct bpf_prog *fp_old, unsigned int size,
101 gfp_t gfp_extra_flags)
103 gfp_t gfp_flags = GFP_KERNEL | __GFP_HIGHMEM | __GFP_ZERO |
107 BUG_ON(fp_old == NULL);
109 size = round_up(size, PAGE_SIZE);
110 if (size <= fp_old->pages * PAGE_SIZE)
113 fp = __vmalloc(size, gfp_flags, PAGE_KERNEL);
115 kmemcheck_annotate_bitfield(fp, meta);
117 memcpy(fp, fp_old, fp_old->pages * PAGE_SIZE);
118 fp->pages = size / PAGE_SIZE;
120 /* We keep fp->aux from fp_old around in the new
121 * reallocated structure.
124 __bpf_prog_free(fp_old);
129 EXPORT_SYMBOL_GPL(bpf_prog_realloc);
131 void __bpf_prog_free(struct bpf_prog *fp)
136 EXPORT_SYMBOL_GPL(__bpf_prog_free);
138 #ifdef CONFIG_BPF_JIT
139 struct bpf_binary_header *
140 bpf_jit_binary_alloc(unsigned int proglen, u8 **image_ptr,
141 unsigned int alignment,
142 bpf_jit_fill_hole_t bpf_fill_ill_insns)
144 struct bpf_binary_header *hdr;
145 unsigned int size, hole, start;
147 /* Most of BPF filters are really small, but if some of them
148 * fill a page, allow at least 128 extra bytes to insert a
149 * random section of illegal instructions.
151 size = round_up(proglen + sizeof(*hdr) + 128, PAGE_SIZE);
152 hdr = module_alloc(size);
156 /* Fill space with illegal/arch-dep instructions. */
157 bpf_fill_ill_insns(hdr, size);
159 hdr->pages = size / PAGE_SIZE;
160 hole = min_t(unsigned int, size - (proglen + sizeof(*hdr)),
161 PAGE_SIZE - sizeof(*hdr));
162 start = (prandom_u32() % hole) & ~(alignment - 1);
164 /* Leave a random number of instructions before BPF code. */
165 *image_ptr = &hdr->image[start];
170 void bpf_jit_binary_free(struct bpf_binary_header *hdr)
174 #endif /* CONFIG_BPF_JIT */
176 /* Base function for offset calculation. Needs to go into .text section,
177 * therefore keeping it non-static as well; will also be used by JITs
178 * anyway later on, so do not let the compiler omit it.
180 noinline u64 __bpf_call_base(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5)
184 EXPORT_SYMBOL_GPL(__bpf_call_base);
187 * __bpf_prog_run - run eBPF program on a given context
188 * @ctx: is the data we are operating on
189 * @insn: is the array of eBPF instructions
191 * Decode and execute eBPF instructions.
193 static unsigned int __bpf_prog_run(void *ctx, const struct bpf_insn *insn)
195 u64 stack[MAX_BPF_STACK / sizeof(u64)];
196 u64 regs[MAX_BPF_REG], tmp;
197 static const void *jumptable[256] = {
198 [0 ... 255] = &&default_label,
199 /* Now overwrite non-defaults ... */
200 /* 32 bit ALU operations */
201 [BPF_ALU | BPF_ADD | BPF_X] = &&ALU_ADD_X,
202 [BPF_ALU | BPF_ADD | BPF_K] = &&ALU_ADD_K,
203 [BPF_ALU | BPF_SUB | BPF_X] = &&ALU_SUB_X,
204 [BPF_ALU | BPF_SUB | BPF_K] = &&ALU_SUB_K,
205 [BPF_ALU | BPF_AND | BPF_X] = &&ALU_AND_X,
206 [BPF_ALU | BPF_AND | BPF_K] = &&ALU_AND_K,
207 [BPF_ALU | BPF_OR | BPF_X] = &&ALU_OR_X,
208 [BPF_ALU | BPF_OR | BPF_K] = &&ALU_OR_K,
209 [BPF_ALU | BPF_LSH | BPF_X] = &&ALU_LSH_X,
210 [BPF_ALU | BPF_LSH | BPF_K] = &&ALU_LSH_K,
211 [BPF_ALU | BPF_RSH | BPF_X] = &&ALU_RSH_X,
212 [BPF_ALU | BPF_RSH | BPF_K] = &&ALU_RSH_K,
213 [BPF_ALU | BPF_XOR | BPF_X] = &&ALU_XOR_X,
214 [BPF_ALU | BPF_XOR | BPF_K] = &&ALU_XOR_K,
215 [BPF_ALU | BPF_MUL | BPF_X] = &&ALU_MUL_X,
216 [BPF_ALU | BPF_MUL | BPF_K] = &&ALU_MUL_K,
217 [BPF_ALU | BPF_MOV | BPF_X] = &&ALU_MOV_X,
218 [BPF_ALU | BPF_MOV | BPF_K] = &&ALU_MOV_K,
219 [BPF_ALU | BPF_DIV | BPF_X] = &&ALU_DIV_X,
220 [BPF_ALU | BPF_DIV | BPF_K] = &&ALU_DIV_K,
221 [BPF_ALU | BPF_MOD | BPF_X] = &&ALU_MOD_X,
222 [BPF_ALU | BPF_MOD | BPF_K] = &&ALU_MOD_K,
223 [BPF_ALU | BPF_NEG] = &&ALU_NEG,
224 [BPF_ALU | BPF_END | BPF_TO_BE] = &&ALU_END_TO_BE,
225 [BPF_ALU | BPF_END | BPF_TO_LE] = &&ALU_END_TO_LE,
226 /* 64 bit ALU operations */
227 [BPF_ALU64 | BPF_ADD | BPF_X] = &&ALU64_ADD_X,
228 [BPF_ALU64 | BPF_ADD | BPF_K] = &&ALU64_ADD_K,
229 [BPF_ALU64 | BPF_SUB | BPF_X] = &&ALU64_SUB_X,
230 [BPF_ALU64 | BPF_SUB | BPF_K] = &&ALU64_SUB_K,
231 [BPF_ALU64 | BPF_AND | BPF_X] = &&ALU64_AND_X,
232 [BPF_ALU64 | BPF_AND | BPF_K] = &&ALU64_AND_K,
233 [BPF_ALU64 | BPF_OR | BPF_X] = &&ALU64_OR_X,
234 [BPF_ALU64 | BPF_OR | BPF_K] = &&ALU64_OR_K,
235 [BPF_ALU64 | BPF_LSH | BPF_X] = &&ALU64_LSH_X,
236 [BPF_ALU64 | BPF_LSH | BPF_K] = &&ALU64_LSH_K,
237 [BPF_ALU64 | BPF_RSH | BPF_X] = &&ALU64_RSH_X,
238 [BPF_ALU64 | BPF_RSH | BPF_K] = &&ALU64_RSH_K,
239 [BPF_ALU64 | BPF_XOR | BPF_X] = &&ALU64_XOR_X,
240 [BPF_ALU64 | BPF_XOR | BPF_K] = &&ALU64_XOR_K,
241 [BPF_ALU64 | BPF_MUL | BPF_X] = &&ALU64_MUL_X,
242 [BPF_ALU64 | BPF_MUL | BPF_K] = &&ALU64_MUL_K,
243 [BPF_ALU64 | BPF_MOV | BPF_X] = &&ALU64_MOV_X,
244 [BPF_ALU64 | BPF_MOV | BPF_K] = &&ALU64_MOV_K,
245 [BPF_ALU64 | BPF_ARSH | BPF_X] = &&ALU64_ARSH_X,
246 [BPF_ALU64 | BPF_ARSH | BPF_K] = &&ALU64_ARSH_K,
247 [BPF_ALU64 | BPF_DIV | BPF_X] = &&ALU64_DIV_X,
248 [BPF_ALU64 | BPF_DIV | BPF_K] = &&ALU64_DIV_K,
249 [BPF_ALU64 | BPF_MOD | BPF_X] = &&ALU64_MOD_X,
250 [BPF_ALU64 | BPF_MOD | BPF_K] = &&ALU64_MOD_K,
251 [BPF_ALU64 | BPF_NEG] = &&ALU64_NEG,
252 /* Call instruction */
253 [BPF_JMP | BPF_CALL] = &&JMP_CALL,
254 [BPF_JMP | BPF_CALL | BPF_X] = &&JMP_TAIL_CALL,
256 [BPF_JMP | BPF_JA] = &&JMP_JA,
257 [BPF_JMP | BPF_JEQ | BPF_X] = &&JMP_JEQ_X,
258 [BPF_JMP | BPF_JEQ | BPF_K] = &&JMP_JEQ_K,
259 [BPF_JMP | BPF_JNE | BPF_X] = &&JMP_JNE_X,
260 [BPF_JMP | BPF_JNE | BPF_K] = &&JMP_JNE_K,
261 [BPF_JMP | BPF_JGT | BPF_X] = &&JMP_JGT_X,
262 [BPF_JMP | BPF_JGT | BPF_K] = &&JMP_JGT_K,
263 [BPF_JMP | BPF_JGE | BPF_X] = &&JMP_JGE_X,
264 [BPF_JMP | BPF_JGE | BPF_K] = &&JMP_JGE_K,
265 [BPF_JMP | BPF_JSGT | BPF_X] = &&JMP_JSGT_X,
266 [BPF_JMP | BPF_JSGT | BPF_K] = &&JMP_JSGT_K,
267 [BPF_JMP | BPF_JSGE | BPF_X] = &&JMP_JSGE_X,
268 [BPF_JMP | BPF_JSGE | BPF_K] = &&JMP_JSGE_K,
269 [BPF_JMP | BPF_JSET | BPF_X] = &&JMP_JSET_X,
270 [BPF_JMP | BPF_JSET | BPF_K] = &&JMP_JSET_K,
272 [BPF_JMP | BPF_EXIT] = &&JMP_EXIT,
273 /* Store instructions */
274 [BPF_STX | BPF_MEM | BPF_B] = &&STX_MEM_B,
275 [BPF_STX | BPF_MEM | BPF_H] = &&STX_MEM_H,
276 [BPF_STX | BPF_MEM | BPF_W] = &&STX_MEM_W,
277 [BPF_STX | BPF_MEM | BPF_DW] = &&STX_MEM_DW,
278 [BPF_STX | BPF_XADD | BPF_W] = &&STX_XADD_W,
279 [BPF_STX | BPF_XADD | BPF_DW] = &&STX_XADD_DW,
280 [BPF_ST | BPF_MEM | BPF_B] = &&ST_MEM_B,
281 [BPF_ST | BPF_MEM | BPF_H] = &&ST_MEM_H,
282 [BPF_ST | BPF_MEM | BPF_W] = &&ST_MEM_W,
283 [BPF_ST | BPF_MEM | BPF_DW] = &&ST_MEM_DW,
284 /* Load instructions */
285 [BPF_LDX | BPF_MEM | BPF_B] = &&LDX_MEM_B,
286 [BPF_LDX | BPF_MEM | BPF_H] = &&LDX_MEM_H,
287 [BPF_LDX | BPF_MEM | BPF_W] = &&LDX_MEM_W,
288 [BPF_LDX | BPF_MEM | BPF_DW] = &&LDX_MEM_DW,
289 [BPF_LD | BPF_ABS | BPF_W] = &&LD_ABS_W,
290 [BPF_LD | BPF_ABS | BPF_H] = &&LD_ABS_H,
291 [BPF_LD | BPF_ABS | BPF_B] = &&LD_ABS_B,
292 [BPF_LD | BPF_IND | BPF_W] = &&LD_IND_W,
293 [BPF_LD | BPF_IND | BPF_H] = &&LD_IND_H,
294 [BPF_LD | BPF_IND | BPF_B] = &&LD_IND_B,
295 [BPF_LD | BPF_IMM | BPF_DW] = &&LD_IMM_DW,
297 u32 tail_call_cnt = 0;
301 #define CONT ({ insn++; goto select_insn; })
302 #define CONT_JMP ({ insn++; goto select_insn; })
304 FP = (u64) (unsigned long) &stack[ARRAY_SIZE(stack)];
305 ARG1 = (u64) (unsigned long) ctx;
307 /* Registers used in classic BPF programs need to be reset first. */
312 goto *jumptable[insn->code];
315 #define ALU(OPCODE, OP) \
316 ALU64_##OPCODE##_X: \
320 DST = (u32) DST OP (u32) SRC; \
322 ALU64_##OPCODE##_K: \
326 DST = (u32) DST OP (u32) IMM; \
357 DST = (u64) (u32) insn[0].imm | ((u64) (u32) insn[1].imm) << 32;
361 (*(s64 *) &DST) >>= SRC;
364 (*(s64 *) &DST) >>= IMM;
367 if (unlikely(SRC == 0))
369 div64_u64_rem(DST, SRC, &tmp);
373 if (unlikely(SRC == 0))
376 DST = do_div(tmp, (u32) SRC);
379 div64_u64_rem(DST, IMM, &tmp);
384 DST = do_div(tmp, (u32) IMM);
387 if (unlikely(SRC == 0))
389 DST = div64_u64(DST, SRC);
392 if (unlikely(SRC == 0))
395 do_div(tmp, (u32) SRC);
399 DST = div64_u64(DST, IMM);
403 do_div(tmp, (u32) IMM);
409 DST = (__force u16) cpu_to_be16(DST);
412 DST = (__force u32) cpu_to_be32(DST);
415 DST = (__force u64) cpu_to_be64(DST);
422 DST = (__force u16) cpu_to_le16(DST);
425 DST = (__force u32) cpu_to_le32(DST);
428 DST = (__force u64) cpu_to_le64(DST);
435 /* Function call scratches BPF_R1-BPF_R5 registers,
436 * preserves BPF_R6-BPF_R9, and stores return value
439 BPF_R0 = (__bpf_call_base + insn->imm)(BPF_R1, BPF_R2, BPF_R3,
444 struct bpf_map *map = (struct bpf_map *) (unsigned long) BPF_R2;
445 struct bpf_array *array = container_of(map, struct bpf_array, map);
446 struct bpf_prog *prog;
449 if (unlikely(index >= array->map.max_entries))
452 if (unlikely(tail_call_cnt > MAX_TAIL_CALL_CNT))
457 prog = READ_ONCE(array->ptrs[index]);
461 /* ARG1 at this point is guaranteed to point to CTX from
462 * the verifier side due to the fact that the tail call is
463 * handeled like a helper, that is, bpf_tail_call_proto,
464 * where arg1_type is ARG_PTR_TO_CTX.
524 if (((s64) DST) > ((s64) SRC)) {
530 if (((s64) DST) > ((s64) IMM)) {
536 if (((s64) DST) >= ((s64) SRC)) {
542 if (((s64) DST) >= ((s64) IMM)) {
562 /* STX and ST and LDX*/
563 #define LDST(SIZEOP, SIZE) \
565 *(SIZE *)(unsigned long) (DST + insn->off) = SRC; \
568 *(SIZE *)(unsigned long) (DST + insn->off) = IMM; \
571 DST = *(SIZE *)(unsigned long) (SRC + insn->off); \
579 STX_XADD_W: /* lock xadd *(u32 *)(dst_reg + off16) += src_reg */
580 atomic_add((u32) SRC, (atomic_t *)(unsigned long)
583 STX_XADD_DW: /* lock xadd *(u64 *)(dst_reg + off16) += src_reg */
584 atomic64_add((u64) SRC, (atomic64_t *)(unsigned long)
587 LD_ABS_W: /* BPF_R0 = ntohl(*(u32 *) (skb->data + imm32)) */
590 /* BPF_LD + BPD_ABS and BPF_LD + BPF_IND insns are
591 * only appearing in the programs where ctx ==
592 * skb. All programs keep 'ctx' in regs[BPF_REG_CTX]
593 * == BPF_R6, bpf_convert_filter() saves it in BPF_R6,
594 * internal BPF verifier will check that BPF_R6 ==
597 * BPF_ABS and BPF_IND are wrappers of function calls,
598 * so they scratch BPF_R1-BPF_R5 registers, preserve
599 * BPF_R6-BPF_R9, and store return value into BPF_R0.
602 * ctx == skb == BPF_R6 == CTX
605 * SRC == any register
606 * IMM == 32-bit immediate
609 * BPF_R0 - 8/16/32-bit skb data converted to cpu endianness
612 ptr = bpf_load_pointer((struct sk_buff *) (unsigned long) CTX, off, 4, &tmp);
613 if (likely(ptr != NULL)) {
614 BPF_R0 = get_unaligned_be32(ptr);
619 LD_ABS_H: /* BPF_R0 = ntohs(*(u16 *) (skb->data + imm32)) */
622 ptr = bpf_load_pointer((struct sk_buff *) (unsigned long) CTX, off, 2, &tmp);
623 if (likely(ptr != NULL)) {
624 BPF_R0 = get_unaligned_be16(ptr);
629 LD_ABS_B: /* BPF_R0 = *(u8 *) (skb->data + imm32) */
632 ptr = bpf_load_pointer((struct sk_buff *) (unsigned long) CTX, off, 1, &tmp);
633 if (likely(ptr != NULL)) {
639 LD_IND_W: /* BPF_R0 = ntohl(*(u32 *) (skb->data + src_reg + imm32)) */
642 LD_IND_H: /* BPF_R0 = ntohs(*(u16 *) (skb->data + src_reg + imm32)) */
645 LD_IND_B: /* BPF_R0 = *(u8 *) (skb->data + src_reg + imm32) */
650 /* If we ever reach this, we have a bug somewhere. */
651 WARN_RATELIMIT(1, "unknown opcode %02x\n", insn->code);
655 bool bpf_prog_array_compatible(struct bpf_array *array,
656 const struct bpf_prog *fp)
658 if (!array->owner_prog_type) {
659 /* There's no owner yet where we could check for
662 array->owner_prog_type = fp->type;
663 array->owner_jited = fp->jited;
668 return array->owner_prog_type == fp->type &&
669 array->owner_jited == fp->jited;
672 static int bpf_check_tail_call(const struct bpf_prog *fp)
674 struct bpf_prog_aux *aux = fp->aux;
677 for (i = 0; i < aux->used_map_cnt; i++) {
678 struct bpf_map *map = aux->used_maps[i];
679 struct bpf_array *array;
681 if (map->map_type != BPF_MAP_TYPE_PROG_ARRAY)
684 array = container_of(map, struct bpf_array, map);
685 if (!bpf_prog_array_compatible(array, fp))
693 * bpf_prog_select_runtime - select exec runtime for BPF program
694 * @fp: bpf_prog populated with internal BPF program
696 * Try to JIT eBPF program, if JIT is not available, use interpreter.
697 * The BPF program will be executed via BPF_PROG_RUN() macro.
699 int bpf_prog_select_runtime(struct bpf_prog *fp)
701 fp->bpf_func = (void *) __bpf_prog_run;
703 bpf_int_jit_compile(fp);
704 bpf_prog_lock_ro(fp);
706 /* The tail call compatibility check can only be done at
707 * this late stage as we need to determine, if we deal
708 * with JITed or non JITed program concatenations and not
709 * all eBPF JITs might immediately support all features.
711 return bpf_check_tail_call(fp);
713 EXPORT_SYMBOL_GPL(bpf_prog_select_runtime);
715 static void bpf_prog_free_deferred(struct work_struct *work)
717 struct bpf_prog_aux *aux;
719 aux = container_of(work, struct bpf_prog_aux, work);
720 bpf_jit_free(aux->prog);
723 /* Free internal BPF program */
724 void bpf_prog_free(struct bpf_prog *fp)
726 struct bpf_prog_aux *aux = fp->aux;
728 INIT_WORK(&aux->work, bpf_prog_free_deferred);
730 schedule_work(&aux->work);
732 EXPORT_SYMBOL_GPL(bpf_prog_free);
734 /* RNG for unpriviledged user space with separated state from prandom_u32(). */
735 static DEFINE_PER_CPU(struct rnd_state, bpf_user_rnd_state);
737 void bpf_user_rnd_init_once(void)
739 prandom_init_once(&bpf_user_rnd_state);
742 u64 bpf_user_rnd_u32(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5)
744 /* Should someone ever have the rather unwise idea to use some
745 * of the registers passed into this function, then note that
746 * this function is called from native eBPF and classic-to-eBPF
747 * transformations. Register assignments from both sides are
748 * different, f.e. classic always sets fn(ctx, A, X) here.
750 struct rnd_state *state;
753 state = &get_cpu_var(bpf_user_rnd_state);
754 res = prandom_u32_state(state);
760 /* Weak definitions of helper functions in case we don't have bpf syscall. */
761 const struct bpf_func_proto bpf_map_lookup_elem_proto __weak;
762 const struct bpf_func_proto bpf_map_update_elem_proto __weak;
763 const struct bpf_func_proto bpf_map_delete_elem_proto __weak;
765 const struct bpf_func_proto bpf_get_prandom_u32_proto __weak;
766 const struct bpf_func_proto bpf_get_smp_processor_id_proto __weak;
767 const struct bpf_func_proto bpf_ktime_get_ns_proto __weak;
768 const struct bpf_func_proto bpf_get_current_pid_tgid_proto __weak;
769 const struct bpf_func_proto bpf_get_current_uid_gid_proto __weak;
770 const struct bpf_func_proto bpf_get_current_comm_proto __weak;
771 const struct bpf_func_proto * __weak bpf_get_trace_printk_proto(void)
776 /* Always built-in helper functions. */
777 const struct bpf_func_proto bpf_tail_call_proto = {
780 .ret_type = RET_VOID,
781 .arg1_type = ARG_PTR_TO_CTX,
782 .arg2_type = ARG_CONST_MAP_PTR,
783 .arg3_type = ARG_ANYTHING,
786 /* For classic BPF JITs that don't implement bpf_int_jit_compile(). */
787 void __weak bpf_int_jit_compile(struct bpf_prog *prog)
791 /* To execute LD_ABS/LD_IND instructions __bpf_prog_run() may call
792 * skb_copy_bits(), so provide a weak definition of it for NET-less config.
794 int __weak skb_copy_bits(const struct sk_buff *skb, int offset, void *to,