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	Version: linux-6.0.1 spark-3.0.0 hadoop-3.2.0-src hadoop-3.3.0-src spark-2.4.7 linux-4.15.13 hadoop-2.7.4-src Revert   Change

 // SPDX-License-Identifier: GPL-2.0-or-later
 /*
  * Linux Socket Filter - Kernel level socket filtering
  *
  * Based on the design of the Berkeley Packet Filter. The new
  * internal format has been designed by PLUMgrid:
  *
  *  Copyright (c) 2011 - 2014 PLUMgrid, http://plumgrid.com
  *
  * Authors:
  *
  *  Jay Schulist <jschlst@samba.org>
  *  Alexei Starovoitov <ast@plumgrid.com>
  *  Daniel Borkmann <dborkman@redhat.com>
  *
  * Andi Kleen - Fix a few bad bugs and races.
  * Kris Katterjohn - Added many additional checks in bpf_check_classic()
  */
 
 #include <uapi/linux/btf.h>
 #include <linux/filter.h>
 #include <linux/skbuff.h>
 #include <linux/vmalloc.h>
 #include <linux/random.h>
 #include <linux/moduleloader.h>
 #include <linux/bpf.h>
 #include <linux/btf.h>
 #include <linux/objtool.h>
 #include <linux/rbtree_latch.h>
 #include <linux/kallsyms.h>
 #include <linux/rcupdate.h>
 #include <linux/perf_event.h>
 #include <linux/extable.h>
 #include <linux/log2.h>
 #include <linux/bpf_verifier.h>
 #include <linux/nodemask.h>
 
 #include <asm/barrier.h>
 #include <asm/unaligned.h>
 
 /* Registers */
 #define BPF_R0  regs[BPF_REG_0]
 #define BPF_R1  regs[BPF_REG_1]
 #define BPF_R2  regs[BPF_REG_2]
 #define BPF_R3  regs[BPF_REG_3]
 #define BPF_R4  regs[BPF_REG_4]
 #define BPF_R5  regs[BPF_REG_5]
 #define BPF_R6  regs[BPF_REG_6]
 #define BPF_R7  regs[BPF_REG_7]
 #define BPF_R8  regs[BPF_REG_8]
 #define BPF_R9  regs[BPF_REG_9]
 #define BPF_R10 regs[BPF_REG_10]
 
 /* Named registers */
 #define DST regs[insn->dst_reg]
 #define SRC regs[insn->src_reg]
 #define FP  regs[BPF_REG_FP]
 #define AX  regs[BPF_REG_AX]
 #define ARG1    regs[BPF_REG_ARG1]
 #define CTX regs[BPF_REG_CTX]
 #define IMM insn->imm
 
 /* No hurry in this branch
  *
  * Exported for the bpf jit load helper.
  */
 void *bpf_internal_load_pointer_neg_helper(const struct sk_buff *skb, int k, unsigned int size)
 {
     u8 *ptr = NULL;
 
     if (k >= SKF_NET_OFF) {
         ptr = skb_network_header(skb) + k - SKF_NET_OFF;
     } else if (k >= SKF_LL_OFF) {
         if (unlikely(!skb_mac_header_was_set(skb)))
             return NULL;
         ptr = skb_mac_header(skb) + k - SKF_LL_OFF;
     }
     if (ptr >= skb->head && ptr + size <= skb_tail_pointer(skb))
         return ptr;
 
     return NULL;
 }
 
 struct bpf_prog *bpf_prog_alloc_no_stats(unsigned int size, gfp_t gfp_extra_flags)
 {
     gfp_t gfp_flags = GFP_KERNEL_ACCOUNT | __GFP_ZERO | gfp_extra_flags;
     struct bpf_prog_aux *aux;
     struct bpf_prog *fp;
 
     size = round_up(size, PAGE_SIZE);
     fp = __vmalloc(size, gfp_flags);
     if (fp == NULL)
         return NULL;
 
     aux = kzalloc(sizeof(*aux), GFP_KERNEL_ACCOUNT | gfp_extra_flags);
     if (aux == NULL) {
         vfree(fp);
         return NULL;
     }
     fp->active = alloc_percpu_gfp(int, GFP_KERNEL_ACCOUNT | gfp_extra_flags);
     if (!fp->active) {
         vfree(fp);
         kfree(aux);
         return NULL;
     }
 
     fp->pages = size / PAGE_SIZE;
     fp->aux = aux;
     fp->aux->prog = fp;
     fp->jit_requested = ebpf_jit_enabled();
     fp->blinding_requested = bpf_jit_blinding_enabled(fp);
 #ifdef CONFIG_CGROUP_BPF
     aux->cgroup_atype = CGROUP_BPF_ATTACH_TYPE_INVALID;
 #endif
 
     INIT_LIST_HEAD_RCU(&fp->aux->ksym.lnode);
     mutex_init(&fp->aux->used_maps_mutex);
     mutex_init(&fp->aux->dst_mutex);
 
     return fp;
 }
 
 struct bpf_prog *bpf_prog_alloc(unsigned int size, gfp_t gfp_extra_flags)
 {
     gfp_t gfp_flags = GFP_KERNEL_ACCOUNT | __GFP_ZERO | gfp_extra_flags;
     struct bpf_prog *prog;
     int cpu;
 
     prog = bpf_prog_alloc_no_stats(size, gfp_extra_flags);
     if (!prog)
         return NULL;
 
     prog->stats = alloc_percpu_gfp(struct bpf_prog_stats, gfp_flags);
     if (!prog->stats) {
         free_percpu(prog->active);
         kfree(prog->aux);
         vfree(prog);
         return NULL;
     }
 
     for_each_possible_cpu(cpu) {
         struct bpf_prog_stats *pstats;
 
         pstats = per_cpu_ptr(prog->stats, cpu);
         u64_stats_init(&pstats->syncp);
     }
     return prog;
 }
 EXPORT_SYMBOL_GPL(bpf_prog_alloc);
 
 int bpf_prog_alloc_jited_linfo(struct bpf_prog *prog)
 {
     if (!prog->aux->nr_linfo || !prog->jit_requested)
         return 0;
 
     prog->aux->jited_linfo = kvcalloc(prog->aux->nr_linfo,
                       sizeof(*prog->aux->jited_linfo),
                       GFP_KERNEL_ACCOUNT | __GFP_NOWARN);
     if (!prog->aux->jited_linfo)
         return -ENOMEM;
 
     return 0;
 }
 
 void bpf_prog_jit_attempt_done(struct bpf_prog *prog)
 {
     if (prog->aux->jited_linfo &&
         (!prog->jited || !prog->aux->jited_linfo[0])) {
         kvfree(prog->aux->jited_linfo);
         prog->aux->jited_linfo = NULL;
     }
 
     kfree(prog->aux->kfunc_tab);
     prog->aux->kfunc_tab = NULL;
 }
 
 /* The jit engine is responsible to provide an array
  * for insn_off to the jited_off mapping (insn_to_jit_off).
  *
  * The idx to this array is the insn_off.  Hence, the insn_off
  * here is relative to the prog itself instead of the main prog.
  * This array has one entry for each xlated bpf insn.
  *
  * jited_off is the byte off to the end of the jited insn.
  *
  * Hence, with
  * insn_start:
  *      The first bpf insn off of the prog.  The insn off
  *      here is relative to the main prog.
  *      e.g. if prog is a subprog, insn_start > 0
  * linfo_idx:
  *      The prog's idx to prog->aux->linfo and jited_linfo
  *
  * jited_linfo[linfo_idx] = prog->bpf_func
  *
  * For i > linfo_idx,
  *
  * jited_linfo[i] = prog->bpf_func +
  *  insn_to_jit_off[linfo[i].insn_off - insn_start - 1]
  */
 void bpf_prog_fill_jited_linfo(struct bpf_prog *prog,
                    const u32 *insn_to_jit_off)
 {
     u32 linfo_idx, insn_start, insn_end, nr_linfo, i;
     const struct bpf_line_info *linfo;
     void **jited_linfo;
 
     if (!prog->aux->jited_linfo)
         /* Userspace did not provide linfo */
         return;
 
     linfo_idx = prog->aux->linfo_idx;
     linfo = &prog->aux->linfo[linfo_idx];
     insn_start = linfo[0].insn_off;
     insn_end = insn_start + prog->len;
 
     jited_linfo = &prog->aux->jited_linfo[linfo_idx];
     jited_linfo[0] = prog->bpf_func;
 
     nr_linfo = prog->aux->nr_linfo - linfo_idx;
 
     for (i = 1; i < nr_linfo && linfo[i].insn_off < insn_end; i++)
         /* The verifier ensures that linfo[i].insn_off is
          * strictly increasing
          */
         jited_linfo[i] = prog->bpf_func +
             insn_to_jit_off[linfo[i].insn_off - insn_start - 1];
 }
 
 struct bpf_prog *bpf_prog_realloc(struct bpf_prog *fp_old, unsigned int size,
                   gfp_t gfp_extra_flags)
 {
     gfp_t gfp_flags = GFP_KERNEL_ACCOUNT | __GFP_ZERO | gfp_extra_flags;
     struct bpf_prog *fp;
     u32 pages;
 
     size = round_up(size, PAGE_SIZE);
     pages = size / PAGE_SIZE;
     if (pages <= fp_old->pages)
         return fp_old;
 
     fp = __vmalloc(size, gfp_flags);
     if (fp) {
         memcpy(fp, fp_old, fp_old->pages * PAGE_SIZE);
         fp->pages = pages;
         fp->aux->prog = fp;
 
         /* We keep fp->aux from fp_old around in the new
          * reallocated structure.
          */
         fp_old->aux = NULL;
         fp_old->stats = NULL;
         fp_old->active = NULL;
         __bpf_prog_free(fp_old);
     }
 
     return fp;
 }
 
 void __bpf_prog_free(struct bpf_prog *fp)
 {
     if (fp->aux) {
         mutex_destroy(&fp->aux->used_maps_mutex);
         mutex_destroy(&fp->aux->dst_mutex);
         kfree(fp->aux->poke_tab);
         kfree(fp->aux);
     }
     free_percpu(fp->stats);
     free_percpu(fp->active);
     vfree(fp);
 }
 
 int bpf_prog_calc_tag(struct bpf_prog *fp)
 {
     const u32 bits_offset = SHA1_BLOCK_SIZE - sizeof(__be64);
     u32 raw_size = bpf_prog_tag_scratch_size(fp);
     u32 digest[SHA1_DIGEST_WORDS];
     u32 ws[SHA1_WORKSPACE_WORDS];
     u32 i, bsize, psize, blocks;
     struct bpf_insn *dst;
     bool was_ld_map;
     u8 *raw, *todo;
     __be32 *result;
     __be64 *bits;
 
     raw = vmalloc(raw_size);
     if (!raw)
         return -ENOMEM;
 
     sha1_init(digest);
     memset(ws, 0, sizeof(ws));
 
     /* We need to take out the map fd for the digest calculation
      * since they are unstable from user space side.
      */
     dst = (void *)raw;
     for (i = 0, was_ld_map = false; i < fp->len; i++) {
         dst[i] = fp->insnsi[i];
         if (!was_ld_map &&
             dst[i].code == (BPF_LD | BPF_IMM | BPF_DW) &&
             (dst[i].src_reg == BPF_PSEUDO_MAP_FD ||
              dst[i].src_reg == BPF_PSEUDO_MAP_VALUE)) {
             was_ld_map = true;
             dst[i].imm = 0;
         } else if (was_ld_map &&
                dst[i].code == 0 &&
                dst[i].dst_reg == 0 &&
                dst[i].src_reg == 0 &&
                dst[i].off == 0) {
             was_ld_map = false;
             dst[i].imm = 0;
         } else {
             was_ld_map = false;
         }
     }
 
     psize = bpf_prog_insn_size(fp);
     memset(&raw[psize], 0, raw_size - psize);
     raw[psize++] = 0x80;
 
     bsize  = round_up(psize, SHA1_BLOCK_SIZE);
     blocks = bsize / SHA1_BLOCK_SIZE;
     todo   = raw;
     if (bsize - psize >= sizeof(__be64)) {
         bits = (__be64 *)(todo + bsize - sizeof(__be64));
     } else {
         bits = (__be64 *)(todo + bsize + bits_offset);
         blocks++;
     }
     *bits = cpu_to_be64((psize - 1) << 3);
 
     while (blocks--) {
         sha1_transform(digest, todo, ws);
         todo += SHA1_BLOCK_SIZE;
     }
 
     result = (__force __be32 *)digest;
     for (i = 0; i < SHA1_DIGEST_WORDS; i++)
         result[i] = cpu_to_be32(digest[i]);
     memcpy(fp->tag, result, sizeof(fp->tag));
 
     vfree(raw);
     return 0;
 }
 
 static int bpf_adj_delta_to_imm(struct bpf_insn *insn, u32 pos, s32 end_old,
                 s32 end_new, s32 curr, const bool probe_pass)
 {
     const s64 imm_min = S32_MIN, imm_max = S32_MAX;
     s32 delta = end_new - end_old;
     s64 imm = insn->imm;
 
     if (curr < pos && curr + imm + 1 >= end_old)
         imm += delta;
     else if (curr >= end_new && curr + imm + 1 < end_new)
         imm -= delta;
     if (imm < imm_min || imm > imm_max)
         return -ERANGE;
     if (!probe_pass)
         insn->imm = imm;
     return 0;
 }
 
 static int bpf_adj_delta_to_off(struct bpf_insn *insn, u32 pos, s32 end_old,
                 s32 end_new, s32 curr, const bool probe_pass)
 {
     const s32 off_min = S16_MIN, off_max = S16_MAX;
     s32 delta = end_new - end_old;
     s32 off = insn->off;
 
     if (curr < pos && curr + off + 1 >= end_old)
         off += delta;
     else if (curr >= end_new && curr + off + 1 < end_new)
         off -= delta;
     if (off < off_min || off > off_max)
         return -ERANGE;
     if (!probe_pass)
         insn->off = off;
     return 0;
 }
 
 static int bpf_adj_branches(struct bpf_prog *prog, u32 pos, s32 end_old,
                 s32 end_new, const bool probe_pass)
 {
     u32 i, insn_cnt = prog->len + (probe_pass ? end_new - end_old : 0);
     struct bpf_insn *insn = prog->insnsi;
     int ret = 0;
 
     for (i = 0; i < insn_cnt; i++, insn++) {
         u8 code;
 
         /* In the probing pass we still operate on the original,
          * unpatched image in order to check overflows before we
          * do any other adjustments. Therefore skip the patchlet.
          */
         if (probe_pass && i == pos) {
             i = end_new;
             insn = prog->insnsi + end_old;
         }
         if (bpf_pseudo_func(insn)) {
             ret = bpf_adj_delta_to_imm(insn, pos, end_old,
                            end_new, i, probe_pass);
             if (ret)
                 return ret;
             continue;
         }
         code = insn->code;
         if ((BPF_CLASS(code) != BPF_JMP &&
              BPF_CLASS(code) != BPF_JMP32) ||
             BPF_OP(code) == BPF_EXIT)
             continue;
         /* Adjust offset of jmps if we cross patch boundaries. */
         if (BPF_OP(code) == BPF_CALL) {
             if (insn->src_reg != BPF_PSEUDO_CALL)
                 continue;
             ret = bpf_adj_delta_to_imm(insn, pos, end_old,
                            end_new, i, probe_pass);
         } else {
             ret = bpf_adj_delta_to_off(insn, pos, end_old,
                            end_new, i, probe_pass);
         }
         if (ret)
             break;
     }
 
     return ret;
 }
 
 static void bpf_adj_linfo(struct bpf_prog *prog, u32 off, u32 delta)
 {
     struct bpf_line_info *linfo;
     u32 i, nr_linfo;
 
     nr_linfo = prog->aux->nr_linfo;
     if (!nr_linfo || !delta)
         return;
 
     linfo = prog->aux->linfo;
 
     for (i = 0; i < nr_linfo; i++)
         if (off < linfo[i].insn_off)
             break;
 
     /* Push all off < linfo[i].insn_off by delta */
     for (; i < nr_linfo; i++)
         linfo[i].insn_off += delta;
 }
 
 struct bpf_prog *bpf_patch_insn_single(struct bpf_prog *prog, u32 off,
                        const struct bpf_insn *patch, u32 len)
 {
     u32 insn_adj_cnt, insn_rest, insn_delta = len - 1;
     const u32 cnt_max = S16_MAX;
     struct bpf_prog *prog_adj;
     int err;
 
     /* Since our patchlet doesn't expand the image, we're done. */
     if (insn_delta == 0) {
         memcpy(prog->insnsi + off, patch, sizeof(*patch));
         return prog;
     }
 
     insn_adj_cnt = prog->len + insn_delta;
 
     /* Reject anything that would potentially let the insn->off
      * target overflow when we have excessive program expansions.
      * We need to probe here before we do any reallocation where
      * we afterwards may not fail anymore.
      */
     if (insn_adj_cnt > cnt_max &&
         (err = bpf_adj_branches(prog, off, off + 1, off + len, true)))
         return ERR_PTR(err);
 
     /* Several new instructions need to be inserted. Make room
      * for them. Likely, there's no need for a new allocation as
      * last page could have large enough tailroom.
      */
     prog_adj = bpf_prog_realloc(prog, bpf_prog_size(insn_adj_cnt),
                     GFP_USER);
     if (!prog_adj)
         return ERR_PTR(-ENOMEM);
 
     prog_adj->len = insn_adj_cnt;
 
     /* Patching happens in 3 steps:
      *
      * 1) Move over tail of insnsi from next instruction onwards,
      *    so we can patch the single target insn with one or more
      *    new ones (patching is always from 1 to n insns, n > 0).
      * 2) Inject new instructions at the target location.
      * 3) Adjust branch offsets if necessary.
      */
     insn_rest = insn_adj_cnt - off - len;
 
     memmove(prog_adj->insnsi + off + len, prog_adj->insnsi + off + 1,
         sizeof(*patch) * insn_rest);
     memcpy(prog_adj->insnsi + off, patch, sizeof(*patch) * len);
 
     /* We are guaranteed to not fail at this point, otherwise
      * the ship has sailed to reverse to the original state. An
      * overflow cannot happen at this point.
      */
     BUG_ON(bpf_adj_branches(prog_adj, off, off + 1, off + len, false));
 
     bpf_adj_linfo(prog_adj, off, insn_delta);
 
     return prog_adj;
 }
 
 int bpf_remove_insns(struct bpf_prog *prog, u32 off, u32 cnt)
 {
     /* Branch offsets can't overflow when program is shrinking, no need
      * to call bpf_adj_branches(..., true) here
      */
     memmove(prog->insnsi + off, prog->insnsi + off + cnt,
         sizeof(struct bpf_insn) * (prog->len - off - cnt));
     prog->len -= cnt;
 
     return WARN_ON_ONCE(bpf_adj_branches(prog, off, off + cnt, off, false));
 }
 
 static void bpf_prog_kallsyms_del_subprogs(struct bpf_prog *fp)
 {
     int i;
 
     for (i = 0; i < fp->aux->func_cnt; i++)
         bpf_prog_kallsyms_del(fp->aux->func[i]);
 }
 
 void bpf_prog_kallsyms_del_all(struct bpf_prog *fp)
 {
     bpf_prog_kallsyms_del_subprogs(fp);
     bpf_prog_kallsyms_del(fp);
 }
 
 #ifdef CONFIG_BPF_JIT
 /* All BPF JIT sysctl knobs here. */
 int bpf_jit_enable   __read_mostly = IS_BUILTIN(CONFIG_BPF_JIT_DEFAULT_ON);
 int bpf_jit_kallsyms __read_mostly = IS_BUILTIN(CONFIG_BPF_JIT_DEFAULT_ON);
 int bpf_jit_harden   __read_mostly;
 long bpf_jit_limit   __read_mostly;
 long bpf_jit_limit_max __read_mostly;
 
 static void
 bpf_prog_ksym_set_addr(struct bpf_prog *prog)
 {
     WARN_ON_ONCE(!bpf_prog_ebpf_jited(prog));
 
     prog->aux->ksym.start = (unsigned long) prog->bpf_func;
     prog->aux->ksym.end   = prog->aux->ksym.start + prog->jited_len;
 }
 
 static void
 bpf_prog_ksym_set_name(struct bpf_prog *prog)
 {
     char *sym = prog->aux->ksym.name;
     const char *end = sym + KSYM_NAME_LEN;
     const struct btf_type *type;
     const char *func_name;
 
     BUILD_BUG_ON(sizeof("bpf_prog_") +
              sizeof(prog->tag) * 2 +
              /* name has been null terminated.
               * We should need +1 for the '_' preceding
               * the name.  However, the null character
               * is double counted between the name and the
               * sizeof("bpf_prog_") above, so we omit
               * the +1 here.
               */
              sizeof(prog->aux->name) > KSYM_NAME_LEN);
 
     sym += snprintf(sym, KSYM_NAME_LEN, "bpf_prog_");
     sym  = bin2hex(sym, prog->tag, sizeof(prog->tag));
 
     /* prog->aux->name will be ignored if full btf name is available */
     if (prog->aux->func_info_cnt) {
         type = btf_type_by_id(prog->aux->btf,
                       prog->aux->func_info[prog->aux->func_idx].type_id);
         func_name = btf_name_by_offset(prog->aux->btf, type->name_off);
         snprintf(sym, (size_t)(end - sym), "_%s", func_name);
         return;
     }
 
     if (prog->aux->name[0])
         snprintf(sym, (size_t)(end - sym), "_%s", prog->aux->name);
     else
         *sym = 0;
 }
 
 static unsigned long bpf_get_ksym_start(struct latch_tree_node *n)
 {
     return container_of(n, struct bpf_ksym, tnode)->start;
 }
 
 static __always_inline bool bpf_tree_less(struct latch_tree_node *a,
                       struct latch_tree_node *b)
 {
     return bpf_get_ksym_start(a) < bpf_get_ksym_start(b);
 }
 
 static __always_inline int bpf_tree_comp(void *key, struct latch_tree_node *n)
 {
     unsigned long val = (unsigned long)key;
     const struct bpf_ksym *ksym;
 
     ksym = container_of(n, struct bpf_ksym, tnode);
 
     if (val < ksym->start)
         return -1;
     if (val >= ksym->end)
         return  1;
 
     return 0;
 }
 
 static const struct latch_tree_ops bpf_tree_ops = {
     .less   = bpf_tree_less,
     .comp   = bpf_tree_comp,
 };
 
 static DEFINE_SPINLOCK(bpf_lock);
 static LIST_HEAD(bpf_kallsyms);
 static struct latch_tree_root bpf_tree __cacheline_aligned;
 
 void bpf_ksym_add(struct bpf_ksym *ksym)
 {
     spin_lock_bh(&bpf_lock);
     WARN_ON_ONCE(!list_empty(&ksym->lnode));
     list_add_tail_rcu(&ksym->lnode, &bpf_kallsyms);
     latch_tree_insert(&ksym->tnode, &bpf_tree, &bpf_tree_ops);
     spin_unlock_bh(&bpf_lock);
 }
 
 static void __bpf_ksym_del(struct bpf_ksym *ksym)
 {
     if (list_empty(&ksym->lnode))
         return;
 
     latch_tree_erase(&ksym->tnode, &bpf_tree, &bpf_tree_ops);
     list_del_rcu(&ksym->lnode);
 }
 
 void bpf_ksym_del(struct bpf_ksym *ksym)
 {
     spin_lock_bh(&bpf_lock);
     __bpf_ksym_del(ksym);
     spin_unlock_bh(&bpf_lock);
 }
 
 static bool bpf_prog_kallsyms_candidate(const struct bpf_prog *fp)
 {
     return fp->jited && !bpf_prog_was_classic(fp);
 }
 
 void bpf_prog_kallsyms_add(struct bpf_prog *fp)
 {
     if (!bpf_prog_kallsyms_candidate(fp) ||
         !bpf_capable())
         return;
 
     bpf_prog_ksym_set_addr(fp);
     bpf_prog_ksym_set_name(fp);
     fp->aux->ksym.prog = true;
 
     bpf_ksym_add(&fp->aux->ksym);
 }
 
 void bpf_prog_kallsyms_del(struct bpf_prog *fp)
 {
     if (!bpf_prog_kallsyms_candidate(fp))
         return;
 
     bpf_ksym_del(&fp->aux->ksym);
 }
 
 static struct bpf_ksym *bpf_ksym_find(unsigned long addr)
 {
     struct latch_tree_node *n;
 
     n = latch_tree_find((void *)addr, &bpf_tree, &bpf_tree_ops);
     return n ? container_of(n, struct bpf_ksym, tnode) : NULL;
 }
 
 const char *__bpf_address_lookup(unsigned long addr, unsigned long *size,
                  unsigned long *off, char *sym)
 {
     struct bpf_ksym *ksym;
     char *ret = NULL;
 
     rcu_read_lock();
     ksym = bpf_ksym_find(addr);
     if (ksym) {
         unsigned long symbol_start = ksym->start;
         unsigned long symbol_end = ksym->end;
 
         strncpy(sym, ksym->name, KSYM_NAME_LEN);
 
         ret = sym;
         if (size)
             *size = symbol_end - symbol_start;
         if (off)
             *off  = addr - symbol_start;
     }
     rcu_read_unlock();
 
     return ret;
 }
 
 bool is_bpf_text_address(unsigned long addr)
 {
     bool ret;
 
     rcu_read_lock();
     ret = bpf_ksym_find(addr) != NULL;
     rcu_read_unlock();
 
     return ret;
 }
 
 static struct bpf_prog *bpf_prog_ksym_find(unsigned long addr)
 {
     struct bpf_ksym *ksym = bpf_ksym_find(addr);
 
     return ksym && ksym->prog ?
            container_of(ksym, struct bpf_prog_aux, ksym)->prog :
            NULL;
 }
 
 const struct exception_table_entry *search_bpf_extables(unsigned long addr)
 {
     const struct exception_table_entry *e = NULL;
     struct bpf_prog *prog;
 
     rcu_read_lock();
     prog = bpf_prog_ksym_find(addr);
     if (!prog)
         goto out;
     if (!prog->aux->num_exentries)
         goto out;
 
     e = search_extable(prog->aux->extable, prog->aux->num_exentries, addr);
 out:
     rcu_read_unlock();
     return e;
 }
 
 int bpf_get_kallsym(unsigned int symnum, unsigned long *value, char *type,
             char *sym)
 {
     struct bpf_ksym *ksym;
     unsigned int it = 0;
     int ret = -ERANGE;
 
     if (!bpf_jit_kallsyms_enabled())
         return ret;
 
     rcu_read_lock();
     list_for_each_entry_rcu(ksym, &bpf_kallsyms, lnode) {
         if (it++ != symnum)
             continue;
 
         strncpy(sym, ksym->name, KSYM_NAME_LEN);
 
         *value = ksym->start;
         *type  = BPF_SYM_ELF_TYPE;
 
         ret = 0;
         break;
     }
     rcu_read_unlock();
 
     return ret;
 }
 
 int bpf_jit_add_poke_descriptor(struct bpf_prog *prog,
                 struct bpf_jit_poke_descriptor *poke)
 {
     struct bpf_jit_poke_descriptor *tab = prog->aux->poke_tab;
     static const u32 poke_tab_max = 1024;
     u32 slot = prog->aux->size_poke_tab;
     u32 size = slot + 1;
 
     if (size > poke_tab_max)
         return -ENOSPC;
     if (poke->tailcall_target || poke->tailcall_target_stable ||
         poke->tailcall_bypass || poke->adj_off || poke->bypass_addr)
         return -EINVAL;
 
     switch (poke->reason) {
     case BPF_POKE_REASON_TAIL_CALL:
         if (!poke->tail_call.map)
             return -EINVAL;
         break;
     default:
         return -EINVAL;
     }
 
     tab = krealloc(tab, size * sizeof(*poke), GFP_KERNEL);
     if (!tab)
         return -ENOMEM;
 
     memcpy(&tab[slot], poke, sizeof(*poke));
     prog->aux->size_poke_tab = size;
     prog->aux->poke_tab = tab;
 
     return slot;
 }
 
 /*
  * BPF program pack allocator.
  *
  * Most BPF programs are pretty small. Allocating a hole page for each
  * program is sometime a waste. Many small bpf program also adds pressure
  * to instruction TLB. To solve this issue, we introduce a BPF program pack
  * allocator. The prog_pack allocator uses HPAGE_PMD_SIZE page (2MB on x86)
  * to host BPF programs.
  */
 #define BPF_PROG_CHUNK_SHIFT    6
 #define BPF_PROG_CHUNK_SIZE (1 << BPF_PROG_CHUNK_SHIFT)
 #define BPF_PROG_CHUNK_MASK (~(BPF_PROG_CHUNK_SIZE - 1))
 
 struct bpf_prog_pack {
     struct list_head list;
     void *ptr;
     unsigned long bitmap[];
 };
 
 #define BPF_PROG_SIZE_TO_NBITS(size)    (round_up(size, BPF_PROG_CHUNK_SIZE) / BPF_PROG_CHUNK_SIZE)
 
 static DEFINE_MUTEX(pack_mutex);
 static LIST_HEAD(pack_list);
 
 /* PMD_SIZE is not available in some special config, e.g. ARCH=arm with
  * CONFIG_MMU=n. Use PAGE_SIZE in these cases.
  */
 #ifdef PMD_SIZE
 #define BPF_PROG_PACK_SIZE (PMD_SIZE * num_possible_nodes())
 #else
 #define BPF_PROG_PACK_SIZE PAGE_SIZE
 #endif
 
 #define BPF_PROG_CHUNK_COUNT (BPF_PROG_PACK_SIZE / BPF_PROG_CHUNK_SIZE)
 
 static struct bpf_prog_pack *alloc_new_pack(bpf_jit_fill_hole_t bpf_fill_ill_insns)
 {
     struct bpf_prog_pack *pack;
 
     pack = kzalloc(struct_size(pack, bitmap, BITS_TO_LONGS(BPF_PROG_CHUNK_COUNT)),
                GFP_KERNEL);
     if (!pack)
         return NULL;
     pack->ptr = module_alloc(BPF_PROG_PACK_SIZE);
     if (!pack->ptr) {
         kfree(pack);
         return NULL;
     }
     bpf_fill_ill_insns(pack->ptr, BPF_PROG_PACK_SIZE);
     bitmap_zero(pack->bitmap, BPF_PROG_PACK_SIZE / BPF_PROG_CHUNK_SIZE);
     list_add_tail(&pack->list, &pack_list);
 
     set_vm_flush_reset_perms(pack->ptr);
     set_memory_ro((unsigned long)pack->ptr, BPF_PROG_PACK_SIZE / PAGE_SIZE);
     set_memory_x((unsigned long)pack->ptr, BPF_PROG_PACK_SIZE / PAGE_SIZE);
     return pack;
 }
 
 static void *bpf_prog_pack_alloc(u32 size, bpf_jit_fill_hole_t bpf_fill_ill_insns)
 {
     unsigned int nbits = BPF_PROG_SIZE_TO_NBITS(size);
     struct bpf_prog_pack *pack;
     unsigned long pos;
     void *ptr = NULL;
 
     mutex_lock(&pack_mutex);
     if (size > BPF_PROG_PACK_SIZE) {
         size = round_up(size, PAGE_SIZE);
         ptr = module_alloc(size);
         if (ptr) {
             bpf_fill_ill_insns(ptr, size);
             set_vm_flush_reset_perms(ptr);
             set_memory_ro((unsigned long)ptr, size / PAGE_SIZE);
             set_memory_x((unsigned long)ptr, size / PAGE_SIZE);
         }
         goto out;
     }
     list_for_each_entry(pack, &pack_list, list) {
         pos = bitmap_find_next_zero_area(pack->bitmap, BPF_PROG_CHUNK_COUNT, 0,
                          nbits, 0);
         if (pos < BPF_PROG_CHUNK_COUNT)
             goto found_free_area;
     }
 
     pack = alloc_new_pack(bpf_fill_ill_insns);
     if (!pack)
         goto out;
 
     pos = 0;
 
 found_free_area:
     bitmap_set(pack->bitmap, pos, nbits);
     ptr = (void *)(pack->ptr) + (pos << BPF_PROG_CHUNK_SHIFT);
 
 out:
     mutex_unlock(&pack_mutex);
     return ptr;
 }
 
 static void bpf_prog_pack_free(struct bpf_binary_header *hdr)
 {
     struct bpf_prog_pack *pack = NULL, *tmp;
     unsigned int nbits;
     unsigned long pos;
 
     mutex_lock(&pack_mutex);
     if (hdr->size > BPF_PROG_PACK_SIZE) {
         module_memfree(hdr);
         goto out;
     }
 
     list_for_each_entry(tmp, &pack_list, list) {
         if ((void *)hdr >= tmp->ptr && (tmp->ptr + BPF_PROG_PACK_SIZE) > (void *)hdr) {
             pack = tmp;
             break;
         }
     }
 
     if (WARN_ONCE(!pack, "bpf_prog_pack bug\n"))
         goto out;
 
     nbits = BPF_PROG_SIZE_TO_NBITS(hdr->size);
     pos = ((unsigned long)hdr - (unsigned long)pack->ptr) >> BPF_PROG_CHUNK_SHIFT;
 
     WARN_ONCE(bpf_arch_text_invalidate(hdr, hdr->size),
           "bpf_prog_pack bug: missing bpf_arch_text_invalidate?\n");
 
     bitmap_clear(pack->bitmap, pos, nbits);
     if (bitmap_find_next_zero_area(pack->bitmap, BPF_PROG_CHUNK_COUNT, 0,
                        BPF_PROG_CHUNK_COUNT, 0) == 0) {
         list_del(&pack->list);
         module_memfree(pack->ptr);
         kfree(pack);
     }
 out:
     mutex_unlock(&pack_mutex);
 }
 
 static atomic_long_t bpf_jit_current;
 
 /* Can be overridden by an arch's JIT compiler if it has a custom,
  * dedicated BPF backend memory area, or if neither of the two
  * below apply.
  */
 u64 __weak bpf_jit_alloc_exec_limit(void)
 {
 #if defined(MODULES_VADDR)
     return MODULES_END - MODULES_VADDR;
 #else
     return VMALLOC_END - VMALLOC_START;
 #endif
 }
 
 static int __init bpf_jit_charge_init(void)
 {
     /* Only used as heuristic here to derive limit. */
     bpf_jit_limit_max = bpf_jit_alloc_exec_limit();
     bpf_jit_limit = min_t(u64, round_up(bpf_jit_limit_max >> 2,
                         PAGE_SIZE), LONG_MAX);
     return 0;
 }
 pure_initcall(bpf_jit_charge_init);
 
 int bpf_jit_charge_modmem(u32 size)
 {
     if (atomic_long_add_return(size, &bpf_jit_current) > READ_ONCE(bpf_jit_limit)) {
         if (!bpf_capable()) {
             atomic_long_sub(size, &bpf_jit_current);
             return -EPERM;
         }
     }
 
     return 0;
 }
 
 void bpf_jit_uncharge_modmem(u32 size)
 {
     atomic_long_sub(size, &bpf_jit_current);
 }
 
 void *__weak bpf_jit_alloc_exec(unsigned long size)
 {
     return module_alloc(size);
 }
 
 void __weak bpf_jit_free_exec(void *addr)
 {
     module_memfree(addr);
 }
 
 struct bpf_binary_header *
 bpf_jit_binary_alloc(unsigned int proglen, u8 **image_ptr,
              unsigned int alignment,
              bpf_jit_fill_hole_t bpf_fill_ill_insns)
 {
     struct bpf_binary_header *hdr;
     u32 size, hole, start;
 
     WARN_ON_ONCE(!is_power_of_2(alignment) ||
              alignment > BPF_IMAGE_ALIGNMENT);
 
     /* Most of BPF filters are really small, but if some of them
      * fill a page, allow at least 128 extra bytes to insert a
      * random section of illegal instructions.
      */
     size = round_up(proglen + sizeof(*hdr) + 128, PAGE_SIZE);
 
     if (bpf_jit_charge_modmem(size))
         return NULL;
     hdr = bpf_jit_alloc_exec(size);
     if (!hdr) {
         bpf_jit_uncharge_modmem(size);
         return NULL;
     }
 
     /* Fill space with illegal/arch-dep instructions. */
     bpf_fill_ill_insns(hdr, size);
 
     hdr->size = size;
     hole = min_t(unsigned int, size - (proglen + sizeof(*hdr)),
              PAGE_SIZE - sizeof(*hdr));
     start = (get_random_int() % hole) & ~(alignment - 1);
 
     /* Leave a random number of instructions before BPF code. */
     *image_ptr = &hdr->image[start];
 
     return hdr;
 }
 
 void bpf_jit_binary_free(struct bpf_binary_header *hdr)
 {
     u32 size = hdr->size;
 
     bpf_jit_free_exec(hdr);
     bpf_jit_uncharge_modmem(size);
 }
 
 /* Allocate jit binary from bpf_prog_pack allocator.
  * Since the allocated memory is RO+X, the JIT engine cannot write directly
  * to the memory. To solve this problem, a RW buffer is also allocated at
  * as the same time. The JIT engine should calculate offsets based on the
  * RO memory address, but write JITed program to the RW buffer. Once the
  * JIT engine finishes, it calls bpf_jit_binary_pack_finalize, which copies
  * the JITed program to the RO memory.
  */
 struct bpf_binary_header *
 bpf_jit_binary_pack_alloc(unsigned int proglen, u8 **image_ptr,
               unsigned int alignment,
               struct bpf_binary_header **rw_header,
               u8 **rw_image,
               bpf_jit_fill_hole_t bpf_fill_ill_insns)
 {
     struct bpf_binary_header *ro_header;
     u32 size, hole, start;
 
     WARN_ON_ONCE(!is_power_of_2(alignment) ||
              alignment > BPF_IMAGE_ALIGNMENT);
 
     /* add 16 bytes for a random section of illegal instructions */
     size = round_up(proglen + sizeof(*ro_header) + 16, BPF_PROG_CHUNK_SIZE);
 
     if (bpf_jit_charge_modmem(size))
         return NULL;
     ro_header = bpf_prog_pack_alloc(size, bpf_fill_ill_insns);
     if (!ro_header) {
         bpf_jit_uncharge_modmem(size);
         return NULL;
     }
 
     *rw_header = kvmalloc(size, GFP_KERNEL);
     if (!*rw_header) {
         bpf_arch_text_copy(&ro_header->size, &size, sizeof(size));
         bpf_prog_pack_free(ro_header);
         bpf_jit_uncharge_modmem(size);
         return NULL;
     }
 
     /* Fill space with illegal/arch-dep instructions. */
     bpf_fill_ill_insns(*rw_header, size);
     (*rw_header)->size = size;
 
     hole = min_t(unsigned int, size - (proglen + sizeof(*ro_header)),
              BPF_PROG_CHUNK_SIZE - sizeof(*ro_header));
     start = (get_random_int() % hole) & ~(alignment - 1);
 
     *image_ptr = &ro_header->image[start];
     *rw_image = &(*rw_header)->image[start];
 
     return ro_header;
 }
 
 /* Copy JITed text from rw_header to its final location, the ro_header. */
 int bpf_jit_binary_pack_finalize(struct bpf_prog *prog,
                  struct bpf_binary_header *ro_header,
                  struct bpf_binary_header *rw_header)
 {
     void *ptr;
 
     ptr = bpf_arch_text_copy(ro_header, rw_header, rw_header->size);
 
     kvfree(rw_header);
 
     if (IS_ERR(ptr)) {
         bpf_prog_pack_free(ro_header);
         return PTR_ERR(ptr);
     }
     return 0;
 }
 
 /* bpf_jit_binary_pack_free is called in two different scenarios:
  *   1) when the program is freed after;
  *   2) when the JIT engine fails (before bpf_jit_binary_pack_finalize).
  * For case 2), we need to free both the RO memory and the RW buffer.
  *
  * bpf_jit_binary_pack_free requires proper ro_header->size. However,
  * bpf_jit_binary_pack_alloc does not set it. Therefore, ro_header->size
  * must be set with either bpf_jit_binary_pack_finalize (normal path) or
  * bpf_arch_text_copy (when jit fails).
  */
 void bpf_jit_binary_pack_free(struct bpf_binary_header *ro_header,
                   struct bpf_binary_header *rw_header)
 {
     u32 size = ro_header->size;
 
     bpf_prog_pack_free(ro_header);
     kvfree(rw_header);
     bpf_jit_uncharge_modmem(size);
 }
 
 struct bpf_binary_header *
 bpf_jit_binary_pack_hdr(const struct bpf_prog *fp)
 {
     unsigned long real_start = (unsigned long)fp->bpf_func;
     unsigned long addr;
 
     addr = real_start & BPF_PROG_CHUNK_MASK;
     return (void *)addr;
 }
 
 static inline struct bpf_binary_header *
 bpf_jit_binary_hdr(const struct bpf_prog *fp)
 {
     unsigned long real_start = (unsigned long)fp->bpf_func;
     unsigned long addr;
 
     addr = real_start & PAGE_MASK;
     return (void *)addr;
 }
 
 /* This symbol is only overridden by archs that have different
  * requirements than the usual eBPF JITs, f.e. when they only
  * implement cBPF JIT, do not set images read-only, etc.
  */
 void __weak bpf_jit_free(struct bpf_prog *fp)
 {
     if (fp->jited) {
         struct bpf_binary_header *hdr = bpf_jit_binary_hdr(fp);
 
         bpf_jit_binary_free(hdr);
         WARN_ON_ONCE(!bpf_prog_kallsyms_verify_off(fp));
     }
 
     bpf_prog_unlock_free(fp);
 }
 
 int bpf_jit_get_func_addr(const struct bpf_prog *prog,
               const struct bpf_insn *insn, bool extra_pass,
               u64 *func_addr, bool *func_addr_fixed)
 {
     s16 off = insn->off;
     s32 imm = insn->imm;
     u8 *addr;
 
     *func_addr_fixed = insn->src_reg != BPF_PSEUDO_CALL;
     if (!*func_addr_fixed) {
         /* Place-holder address till the last pass has collected
          * all addresses for JITed subprograms in which case we
          * can pick them up from prog->aux.
          */
         if (!extra_pass)
             addr = NULL;
         else if (prog->aux->func &&
              off >= 0 && off < prog->aux->func_cnt)
             addr = (u8 *)prog->aux->func[off]->bpf_func;
         else
             return -EINVAL;
     } else {
         /* Address of a BPF helper call. Since part of the core
          * kernel, it's always at a fixed location. __bpf_call_base
          * and the helper with imm relative to it are both in core
          * kernel.
          */
         addr = (u8 *)__bpf_call_base + imm;
     }
 
     *func_addr = (unsigned long)addr;
     return 0;
 }
 
 static int bpf_jit_blind_insn(const struct bpf_insn *from,
                   const struct bpf_insn *aux,
                   struct bpf_insn *to_buff,
                   bool emit_zext)
 {
     struct bpf_insn *to = to_buff;
     u32 imm_rnd = get_random_int();
     s16 off;
 
     BUILD_BUG_ON(BPF_REG_AX  + 1 != MAX_BPF_JIT_REG);
     BUILD_BUG_ON(MAX_BPF_REG + 1 != MAX_BPF_JIT_REG);
 
     /* Constraints on AX register:
      *
      * AX register is inaccessible from user space. It is mapped in
      * all JITs, and used here for constant blinding rewrites. It is
      * typically "stateless" meaning its contents are only valid within
      * the executed instruction, but not across several instructions.
      * There are a few exceptions however which are further detailed
      * below.
      *
      * Constant blinding is only used by JITs, not in the interpreter.
      * The interpreter uses AX in some occasions as a local temporary
      * register e.g. in DIV or MOD instructions.
      *
      * In restricted circumstances, the verifier can also use the AX
      * register for rewrites as long as they do not interfere with
      * the above cases!
      */
     if (from->dst_reg == BPF_REG_AX || from->src_reg == BPF_REG_AX)
         goto out;
 
     if (from->imm == 0 &&
         (from->code == (BPF_ALU   | BPF_MOV | BPF_K) ||
          from->code == (BPF_ALU64 | BPF_MOV | BPF_K))) {
         *to++ = BPF_ALU64_REG(BPF_XOR, from->dst_reg, from->dst_reg);
         goto out;
     }
 
     switch (from->code) {
     case BPF_ALU | BPF_ADD | BPF_K:
     case BPF_ALU | BPF_SUB | BPF_K:
     case BPF_ALU | BPF_AND | BPF_K:
     case BPF_ALU | BPF_OR  | BPF_K:
     case BPF_ALU | BPF_XOR | BPF_K:
     case BPF_ALU | BPF_MUL | BPF_K:
     case BPF_ALU | BPF_MOV | BPF_K:
     case BPF_ALU | BPF_DIV | BPF_K:
     case BPF_ALU | BPF_MOD | BPF_K:
         *to++ = BPF_ALU32_IMM(BPF_MOV, BPF_REG_AX, imm_rnd ^ from->imm);
         *to++ = BPF_ALU32_IMM(BPF_XOR, BPF_REG_AX, imm_rnd);
         *to++ = BPF_ALU32_REG(from->code, from->dst_reg, BPF_REG_AX);
         break;
 
     case BPF_ALU64 | BPF_ADD | BPF_K:
     case BPF_ALU64 | BPF_SUB | BPF_K:
     case BPF_ALU64 | BPF_AND | BPF_K:
     case BPF_ALU64 | BPF_OR  | BPF_K:
     case BPF_ALU64 | BPF_XOR | BPF_K:
     case BPF_ALU64 | BPF_MUL | BPF_K:
     case BPF_ALU64 | BPF_MOV | BPF_K:
     case BPF_ALU64 | BPF_DIV | BPF_K:
     case BPF_ALU64 | BPF_MOD | BPF_K:
         *to++ = BPF_ALU64_IMM(BPF_MOV, BPF_REG_AX, imm_rnd ^ from->imm);
         *to++ = BPF_ALU64_IMM(BPF_XOR, BPF_REG_AX, imm_rnd);
         *to++ = BPF_ALU64_REG(from->code, from->dst_reg, BPF_REG_AX);
         break;
 
     case BPF_JMP | BPF_JEQ  | BPF_K:
     case BPF_JMP | BPF_JNE  | BPF_K:
     case BPF_JMP | BPF_JGT  | BPF_K:
     case BPF_JMP | BPF_JLT  | BPF_K:
     case BPF_JMP | BPF_JGE  | BPF_K:
     case BPF_JMP | BPF_JLE  | BPF_K:
     case BPF_JMP | BPF_JSGT | BPF_K:
     case BPF_JMP | BPF_JSLT | BPF_K:
     case BPF_JMP | BPF_JSGE | BPF_K:
     case BPF_JMP | BPF_JSLE | BPF_K:
     case BPF_JMP | BPF_JSET | BPF_K:
         /* Accommodate for extra offset in case of a backjump. */
         off = from->off;
         if (off < 0)
             off -= 2;
         *to++ = BPF_ALU64_IMM(BPF_MOV, BPF_REG_AX, imm_rnd ^ from->imm);
         *to++ = BPF_ALU64_IMM(BPF_XOR, BPF_REG_AX, imm_rnd);
         *to++ = BPF_JMP_REG(from->code, from->dst_reg, BPF_REG_AX, off);
         break;
 
     case BPF_JMP32 | BPF_JEQ  | BPF_K:
     case BPF_JMP32 | BPF_JNE  | BPF_K:
     case BPF_JMP32 | BPF_JGT  | BPF_K:
     case BPF_JMP32 | BPF_JLT  | BPF_K:
     case BPF_JMP32 | BPF_JGE  | BPF_K:
     case BPF_JMP32 | BPF_JLE  | BPF_K:
     case BPF_JMP32 | BPF_JSGT | BPF_K:
     case BPF_JMP32 | BPF_JSLT | BPF_K:
     case BPF_JMP32 | BPF_JSGE | BPF_K:
     case BPF_JMP32 | BPF_JSLE | BPF_K:
     case BPF_JMP32 | BPF_JSET | BPF_K:
         /* Accommodate for extra offset in case of a backjump. */
         off = from->off;
         if (off < 0)
             off -= 2;
         *to++ = BPF_ALU32_IMM(BPF_MOV, BPF_REG_AX, imm_rnd ^ from->imm);
         *to++ = BPF_ALU32_IMM(BPF_XOR, BPF_REG_AX, imm_rnd);
         *to++ = BPF_JMP32_REG(from->code, from->dst_reg, BPF_REG_AX,
                       off);
         break;
 
     case BPF_LD | BPF_IMM | BPF_DW:
         *to++ = BPF_ALU64_IMM(BPF_MOV, BPF_REG_AX, imm_rnd ^ aux[1].imm);
         *to++ = BPF_ALU64_IMM(BPF_XOR, BPF_REG_AX, imm_rnd);
         *to++ = BPF_ALU64_IMM(BPF_LSH, BPF_REG_AX, 32);
         *to++ = BPF_ALU64_REG(BPF_MOV, aux[0].dst_reg, BPF_REG_AX);
         break;
     case 0: /* Part 2 of BPF_LD | BPF_IMM | BPF_DW. */
         *to++ = BPF_ALU32_IMM(BPF_MOV, BPF_REG_AX, imm_rnd ^ aux[0].imm);
         *to++ = BPF_ALU32_IMM(BPF_XOR, BPF_REG_AX, imm_rnd);
         if (emit_zext)
             *to++ = BPF_ZEXT_REG(BPF_REG_AX);
         *to++ = BPF_ALU64_REG(BPF_OR,  aux[0].dst_reg, BPF_REG_AX);
         break;
 
     case BPF_ST | BPF_MEM | BPF_DW:
     case BPF_ST | BPF_MEM | BPF_W:
     case BPF_ST | BPF_MEM | BPF_H:
     case BPF_ST | BPF_MEM | BPF_B:
         *to++ = BPF_ALU64_IMM(BPF_MOV, BPF_REG_AX, imm_rnd ^ from->imm);
         *to++ = BPF_ALU64_IMM(BPF_XOR, BPF_REG_AX, imm_rnd);
         *to++ = BPF_STX_MEM(from->code, from->dst_reg, BPF_REG_AX, from->off);
         break;
     }
 out:
     return to - to_buff;
 }
 
 static struct bpf_prog *bpf_prog_clone_create(struct bpf_prog *fp_other,
                           gfp_t gfp_extra_flags)
 {
     gfp_t gfp_flags = GFP_KERNEL | __GFP_ZERO | gfp_extra_flags;
     struct bpf_prog *fp;
 
     fp = __vmalloc(fp_other->pages * PAGE_SIZE, gfp_flags);
     if (fp != NULL) {
         /* aux->prog still points to the fp_other one, so
          * when promoting the clone to the real program,
          * this still needs to be adapted.
          */
         memcpy(fp, fp_other, fp_other->pages * PAGE_SIZE);
     }
 
     return fp;
 }
 
 static void bpf_prog_clone_free(struct bpf_prog *fp)
 {
     /* aux was stolen by the other clone, so we cannot free
      * it from this path! It will be freed eventually by the
      * other program on release.
      *
      * At this point, we don't need a deferred release since
      * clone is guaranteed to not be locked.
      */
     fp->aux = NULL;
     fp->stats = NULL;
     fp->active = NULL;
     __bpf_prog_free(fp);
 }
 
 void bpf_jit_prog_release_other(struct bpf_prog *fp, struct bpf_prog *fp_other)
 {
     /* We have to repoint aux->prog to self, as we don't
      * know whether fp here is the clone or the original.
      */
     fp->aux->prog = fp;
     bpf_prog_clone_free(fp_other);
 }
 
 struct bpf_prog *bpf_jit_blind_constants(struct bpf_prog *prog)
 {
     struct bpf_insn insn_buff[16], aux[2];
     struct bpf_prog *clone, *tmp;
     int insn_delta, insn_cnt;
     struct bpf_insn *insn;
     int i, rewritten;
 
     if (!prog->blinding_requested || prog->blinded)
         return prog;
 
     clone = bpf_prog_clone_create(prog, GFP_USER);
     if (!clone)
         return ERR_PTR(-ENOMEM);
 
     insn_cnt = clone->len;
     insn = clone->insnsi;
 
     for (i = 0; i < insn_cnt; i++, insn++) {
         if (bpf_pseudo_func(insn)) {
             /* ld_imm64 with an address of bpf subprog is not
              * a user controlled constant. Don't randomize it,
              * since it will conflict with jit_subprogs() logic.
              */
             insn++;
             i++;
             continue;
         }
 
         /* We temporarily need to hold the original ld64 insn
          * so that we can still access the first part in the
          * second blinding run.
          */
         if (insn[0].code == (BPF_LD | BPF_IMM | BPF_DW) &&
             insn[1].code == 0)
             memcpy(aux, insn, sizeof(aux));
 
         rewritten = bpf_jit_blind_insn(insn, aux, insn_buff,
                         clone->aux->verifier_zext);
         if (!rewritten)
             continue;
 
         tmp = bpf_patch_insn_single(clone, i, insn_buff, rewritten);
         if (IS_ERR(tmp)) {
             /* Patching may have repointed aux->prog during
              * realloc from the original one, so we need to
              * fix it up here on error.
              */
             bpf_jit_prog_release_other(prog, clone);
             return tmp;
         }
 
         clone = tmp;
         insn_delta = rewritten - 1;
 
         /* Walk new program and skip insns we just inserted. */
         insn = clone->insnsi + i + insn_delta;
         insn_cnt += insn_delta;
         i        += insn_delta;
     }
 
     clone->blinded = 1;
     return clone;
 }
 #endif /* CONFIG_BPF_JIT */
 
 /* Base function for offset calculation. Needs to go into .text section,
  * therefore keeping it non-static as well; will also be used by JITs
  * anyway later on, so do not let the compiler omit it. This also needs
  * to go into kallsyms for correlation from e.g. bpftool, so naming
  * must not change.
  */
 noinline u64 __bpf_call_base(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5)
 {
     return 0;
 }
 EXPORT_SYMBOL_GPL(__bpf_call_base);
 
 /* All UAPI available opcodes. */
 #define BPF_INSN_MAP(INSN_2, INSN_3)        \
     /* 32 bit ALU operations. */        \
     /*   Register based. */         \
     INSN_3(ALU, ADD,  X),           \
     INSN_3(ALU, SUB,  X),           \
     INSN_3(ALU, AND,  X),           \
     INSN_3(ALU, OR,   X),           \
     INSN_3(ALU, LSH,  X),           \
     INSN_3(ALU, RSH,  X),           \
     INSN_3(ALU, XOR,  X),           \
     INSN_3(ALU, MUL,  X),           \
     INSN_3(ALU, MOV,  X),           \
     INSN_3(ALU, ARSH, X),           \
     INSN_3(ALU, DIV,  X),           \
     INSN_3(ALU, MOD,  X),           \
     INSN_2(ALU, NEG),           \
     INSN_3(ALU, END, TO_BE),        \
     INSN_3(ALU, END, TO_LE),        \
     /*   Immediate based. */        \
     INSN_3(ALU, ADD,  K),           \
     INSN_3(ALU, SUB,  K),           \
     INSN_3(ALU, AND,  K),           \
     INSN_3(ALU, OR,   K),           \
     INSN_3(ALU, LSH,  K),           \
     INSN_3(ALU, RSH,  K),           \
     INSN_3(ALU, XOR,  K),           \
     INSN_3(ALU, MUL,  K),           \
     INSN_3(ALU, MOV,  K),           \
     INSN_3(ALU, ARSH, K),           \
     INSN_3(ALU, DIV,  K),           \
     INSN_3(ALU, MOD,  K),           \
     /* 64 bit ALU operations. */        \
     /*   Register based. */         \
     INSN_3(ALU64, ADD,  X),         \
     INSN_3(ALU64, SUB,  X),         \
     INSN_3(ALU64, AND,  X),         \
     INSN_3(ALU64, OR,   X),         \
     INSN_3(ALU64, LSH,  X),         \
     INSN_3(ALU64, RSH,  X),         \
     INSN_3(ALU64, XOR,  X),         \
     INSN_3(ALU64, MUL,  X),         \
     INSN_3(ALU64, MOV,  X),         \
     INSN_3(ALU64, ARSH, X),         \
     INSN_3(ALU64, DIV,  X),         \
     INSN_3(ALU64, MOD,  X),         \
     INSN_2(ALU64, NEG),         \
     /*   Immediate based. */        \
     INSN_3(ALU64, ADD,  K),         \
     INSN_3(ALU64, SUB,  K),         \
     INSN_3(ALU64, AND,  K),         \
     INSN_3(ALU64, OR,   K),         \
     INSN_3(ALU64, LSH,  K),         \
     INSN_3(ALU64, RSH,  K),         \
     INSN_3(ALU64, XOR,  K),         \
     INSN_3(ALU64, MUL,  K),         \
     INSN_3(ALU64, MOV,  K),         \
     INSN_3(ALU64, ARSH, K),         \
     INSN_3(ALU64, DIV,  K),         \
     INSN_3(ALU64, MOD,  K),         \
     /* Call instruction. */         \
     INSN_2(JMP, CALL),          \
     /* Exit instruction. */         \
     INSN_2(JMP, EXIT),          \
     /* 32-bit Jump instructions. */     \
     /*   Register based. */         \
     INSN_3(JMP32, JEQ,  X),         \
     INSN_3(JMP32, JNE,  X),         \
     INSN_3(JMP32, JGT,  X),         \
     INSN_3(JMP32, JLT,  X),         \
     INSN_3(JMP32, JGE,  X),         \
     INSN_3(JMP32, JLE,  X),         \
     INSN_3(JMP32, JSGT, X),         \
     INSN_3(JMP32, JSLT, X),         \
     INSN_3(JMP32, JSGE, X),         \
     INSN_3(JMP32, JSLE, X),         \
     INSN_3(JMP32, JSET, X),         \
     /*   Immediate based. */        \
     INSN_3(JMP32, JEQ,  K),         \
     INSN_3(JMP32, JNE,  K),         \
     INSN_3(JMP32, JGT,  K),         \
     INSN_3(JMP32, JLT,  K),         \
     INSN_3(JMP32, JGE,  K),         \
     INSN_3(JMP32, JLE,  K),         \
     INSN_3(JMP32, JSGT, K),         \
     INSN_3(JMP32, JSLT, K),         \
     INSN_3(JMP32, JSGE, K),         \
     INSN_3(JMP32, JSLE, K),         \
     INSN_3(JMP32, JSET, K),         \
     /* Jump instructions. */        \
     /*   Register based. */         \
     INSN_3(JMP, JEQ,  X),           \
     INSN_3(JMP, JNE,  X),           \
     INSN_3(JMP, JGT,  X),           \
     INSN_3(JMP, JLT,  X),           \
     INSN_3(JMP, JGE,  X),           \
     INSN_3(JMP, JLE,  X),           \
     INSN_3(JMP, JSGT, X),           \
     INSN_3(JMP, JSLT, X),           \
     INSN_3(JMP, JSGE, X),           \
     INSN_3(JMP, JSLE, X),           \
     INSN_3(JMP, JSET, X),           \
     /*   Immediate based. */        \
     INSN_3(JMP, JEQ,  K),           \
     INSN_3(JMP, JNE,  K),           \
     INSN_3(JMP, JGT,  K),           \
     INSN_3(JMP, JLT,  K),           \
     INSN_3(JMP, JGE,  K),           \
     INSN_3(JMP, JLE,  K),           \
     INSN_3(JMP, JSGT, K),           \
     INSN_3(JMP, JSLT, K),           \
     INSN_3(JMP, JSGE, K),           \
     INSN_3(JMP, JSLE, K),           \
     INSN_3(JMP, JSET, K),           \
     INSN_2(JMP, JA),            \
     /* Store instructions. */       \
     /*   Register based. */         \
     INSN_3(STX, MEM,  B),           \
     INSN_3(STX, MEM,  H),           \
     INSN_3(STX, MEM,  W),           \
     INSN_3(STX, MEM,  DW),          \
     INSN_3(STX, ATOMIC, W),         \
     INSN_3(STX, ATOMIC, DW),        \
     /*   Immediate based. */        \
     INSN_3(ST, MEM, B),         \
     INSN_3(ST, MEM, H),         \
     INSN_3(ST, MEM, W),         \
     INSN_3(ST, MEM, DW),            \
     /* Load instructions. */        \
     /*   Register based. */         \
     INSN_3(LDX, MEM, B),            \
     INSN_3(LDX, MEM, H),            \
     INSN_3(LDX, MEM, W),            \
     INSN_3(LDX, MEM, DW),           \
     /*   Immediate based. */        \
     INSN_3(LD, IMM, DW)
 
 bool bpf_opcode_in_insntable(u8 code)
 {
 #define BPF_INSN_2_TBL(x, y)    [BPF_##x | BPF_##y] = true
 #define BPF_INSN_3_TBL(x, y, z) [BPF_##x | BPF_##y | BPF_##z] = true
     static const bool public_insntable[256] = {
         [0 ... 255] = false,
         /* Now overwrite non-defaults ... */
         BPF_INSN_MAP(BPF_INSN_2_TBL, BPF_INSN_3_TBL),
         /* UAPI exposed, but rewritten opcodes. cBPF carry-over. */
         [BPF_LD | BPF_ABS | BPF_B] = true,
         [BPF_LD | BPF_ABS | BPF_H] = true,
         [BPF_LD | BPF_ABS | BPF_W] = true,
         [BPF_LD | BPF_IND | BPF_B] = true,
         [BPF_LD | BPF_IND | BPF_H] = true,
         [BPF_LD | BPF_IND | BPF_W] = true,
     };
 #undef BPF_INSN_3_TBL
 #undef BPF_INSN_2_TBL
     return public_insntable[code];
 }
 
 #ifndef CONFIG_BPF_JIT_ALWAYS_ON
 u64 __weak bpf_probe_read_kernel(void *dst, u32 size, const void *unsafe_ptr)
 {
     memset(dst, 0, size);
     return -EFAULT;
 }
 
 /**
  *  ___bpf_prog_run - run eBPF program on a given context
  *  @regs: is the array of MAX_BPF_EXT_REG eBPF pseudo-registers
  *  @insn: is the array of eBPF instructions
  *
  * Decode and execute eBPF instructions.
  *
  * Return: whatever value is in %BPF_R0 at program exit
  */
 static u64 ___bpf_prog_run(u64 *regs, const struct bpf_insn *insn)
 {
 #define BPF_INSN_2_LBL(x, y)    [BPF_##x | BPF_##y] = &&x##_##y
 #define BPF_INSN_3_LBL(x, y, z) [BPF_##x | BPF_##y | BPF_##z] = &&x##_##y##_##z
     static const void * const jumptable[256] __annotate_jump_table = {
         [0 ... 255] = &&default_label,
         /* Now overwrite non-defaults ... */
         BPF_INSN_MAP(BPF_INSN_2_LBL, BPF_INSN_3_LBL),
         /* Non-UAPI available opcodes. */
         [BPF_JMP | BPF_CALL_ARGS] = &&JMP_CALL_ARGS,
         [BPF_JMP | BPF_TAIL_CALL] = &&JMP_TAIL_CALL,
         [BPF_ST  | BPF_NOSPEC] = &&ST_NOSPEC,
         [BPF_LDX | BPF_PROBE_MEM | BPF_B] = &&LDX_PROBE_MEM_B,
         [BPF_LDX | BPF_PROBE_MEM | BPF_H] = &&LDX_PROBE_MEM_H,
         [BPF_LDX | BPF_PROBE_MEM | BPF_W] = &&LDX_PROBE_MEM_W,
         [BPF_LDX | BPF_PROBE_MEM | BPF_DW] = &&LDX_PROBE_MEM_DW,
     };
 #undef BPF_INSN_3_LBL
 #undef BPF_INSN_2_LBL
     u32 tail_call_cnt = 0;
 
 #define CONT     ({ insn++; goto select_insn; })
 #define CONT_JMP ({ insn++; goto select_insn; })
 
 select_insn:
     goto *jumptable[insn->code];
 
     /* Explicitly mask the register-based shift amounts with 63 or 31
      * to avoid undefined behavior. Normally this won't affect the
      * generated code, for example, in case of native 64 bit archs such
      * as x86-64 or arm64, the compiler is optimizing the AND away for
      * the interpreter. In case of JITs, each of the JIT backends compiles
      * the BPF shift operations to machine instructions which produce
      * implementation-defined results in such a case; the resulting
      * contents of the register may be arbitrary, but program behaviour
      * as a whole remains defined. In other words, in case of JIT backends,
      * the AND must /not/ be added to the emitted LSH/RSH/ARSH translation.
      */
     /* ALU (shifts) */
 #define SHT(OPCODE, OP)                 \
     ALU64_##OPCODE##_X:             \
         DST = DST OP (SRC & 63);        \
         CONT;                   \
     ALU_##OPCODE##_X:               \
         DST = (u32) DST OP ((u32) SRC & 31);    \
         CONT;                   \
     ALU64_##OPCODE##_K:             \
         DST = DST OP IMM;           \
         CONT;                   \
     ALU_##OPCODE##_K:               \
         DST = (u32) DST OP (u32) IMM;       \
         CONT;
     /* ALU (rest) */
 #define ALU(OPCODE, OP)                 \
     ALU64_##OPCODE##_X:             \
         DST = DST OP SRC;           \
         CONT;                   \
     ALU_##OPCODE##_X:               \
         DST = (u32) DST OP (u32) SRC;       \
         CONT;                   \
     ALU64_##OPCODE##_K:             \
         DST = DST OP IMM;           \
         CONT;                   \
     ALU_##OPCODE##_K:               \
         DST = (u32) DST OP (u32) IMM;       \
         CONT;
     ALU(ADD,  +)
     ALU(SUB,  -)
     ALU(AND,  &)
     ALU(OR,   |)
     ALU(XOR,  ^)
     ALU(MUL,  *)
     SHT(LSH, <<)
     SHT(RSH, >>)
 #undef SHT
 #undef ALU
     ALU_NEG:
         DST = (u32) -DST;
         CONT;
     ALU64_NEG:
         DST = -DST;
         CONT;
     ALU_MOV_X:
         DST = (u32) SRC;
         CONT;
     ALU_MOV_K:
         DST = (u32) IMM;
         CONT;
     ALU64_MOV_X:
         DST = SRC;
         CONT;
     ALU64_MOV_K:
         DST = IMM;
         CONT;
     LD_IMM_DW:
         DST = (u64) (u32) insn[0].imm | ((u64) (u32) insn[1].imm) << 32;
         insn++;
         CONT;
     ALU_ARSH_X:
         DST = (u64) (u32) (((s32) DST) >> (SRC & 31));
         CONT;
     ALU_ARSH_K:
         DST = (u64) (u32) (((s32) DST) >> IMM);
         CONT;
     ALU64_ARSH_X:
         (*(s64 *) &DST) >>= (SRC & 63);
         CONT;
     ALU64_ARSH_K:
         (*(s64 *) &DST) >>= IMM;
         CONT;
     ALU64_MOD_X:
         div64_u64_rem(DST, SRC, &AX);
         DST = AX;
         CONT;
     ALU_MOD_X:
         AX = (u32) DST;
         DST = do_div(AX, (u32) SRC);
         CONT;
     ALU64_MOD_K:
         div64_u64_rem(DST, IMM, &AX);
         DST = AX;
         CONT;
     ALU_MOD_K:
         AX = (u32) DST;
         DST = do_div(AX, (u32) IMM);
         CONT;
     ALU64_DIV_X:
         DST = div64_u64(DST, SRC);
         CONT;
     ALU_DIV_X:
         AX = (u32) DST;
         do_div(AX, (u32) SRC);
         DST = (u32) AX;
         CONT;
     ALU64_DIV_K:
         DST = div64_u64(DST, IMM);
         CONT;
     ALU_DIV_K:
         AX = (u32) DST;
         do_div(AX, (u32) IMM);
         DST = (u32) AX;
         CONT;
     ALU_END_TO_BE:
         switch (IMM) {
         case 16:
             DST = (__force u16) cpu_to_be16(DST);
             break;
         case 32:
             DST = (__force u32) cpu_to_be32(DST);
             break;
         case 64:
             DST = (__force u64) cpu_to_be64(DST);
             break;
         }
         CONT;
     ALU_END_TO_LE:
         switch (IMM) {
         case 16:
             DST = (__force u16) cpu_to_le16(DST);
             break;
         case 32:
             DST = (__force u32) cpu_to_le32(DST);
             break;
         case 64:
             DST = (__force u64) cpu_to_le64(DST);
             break;
         }
         CONT;
 
     /* CALL */
     JMP_CALL:
         /* Function call scratches BPF_R1-BPF_R5 registers,
          * preserves BPF_R6-BPF_R9, and stores return value
          * into BPF_R0.
          */
         BPF_R0 = (__bpf_call_base + insn->imm)(BPF_R1, BPF_R2, BPF_R3,
                                BPF_R4, BPF_R5);
         CONT;
 
     JMP_CALL_ARGS:
         BPF_R0 = (__bpf_call_base_args + insn->imm)(BPF_R1, BPF_R2,
                                 BPF_R3, BPF_R4,
                                 BPF_R5,
                                 insn + insn->off + 1);
         CONT;
 
     JMP_TAIL_CALL: {
         struct bpf_map *map = (struct bpf_map *) (unsigned long) BPF_R2;
         struct bpf_array *array = container_of(map, struct bpf_array, map);
         struct bpf_prog *prog;
         u32 index = BPF_R3;
 
         if (unlikely(index >= array->map.max_entries))
             goto out;
 
         if (unlikely(tail_call_cnt >= MAX_TAIL_CALL_CNT))
             goto out;
 
         tail_call_cnt++;
 
         prog = READ_ONCE(array->ptrs[index]);
         if (!prog)
             goto out;
 
         /* ARG1 at this point is guaranteed to point to CTX from
          * the verifier side due to the fact that the tail call is
          * handled like a helper, that is, bpf_tail_call_proto,
          * where arg1_type is ARG_PTR_TO_CTX.
          */
         insn = prog->insnsi;
         goto select_insn;
 out:
         CONT;
     }
     JMP_JA:
         insn += insn->off;
         CONT;
     JMP_EXIT:
         return BPF_R0;
     /* JMP */
 #define COND_JMP(SIGN, OPCODE, CMP_OP)              \
     JMP_##OPCODE##_X:                   \
         if ((SIGN##64) DST CMP_OP (SIGN##64) SRC) { \
             insn += insn->off;          \
             CONT_JMP;               \
         }                       \
         CONT;                       \
     JMP32_##OPCODE##_X:                 \
         if ((SIGN##32) DST CMP_OP (SIGN##32) SRC) { \
             insn += insn->off;          \
             CONT_JMP;               \
         }                       \
         CONT;                       \
     JMP_##OPCODE##_K:                   \
         if ((SIGN##64) DST CMP_OP (SIGN##64) IMM) { \
             insn += insn->off;          \
             CONT_JMP;               \
         }                       \
         CONT;                       \
     JMP32_##OPCODE##_K:                 \
         if ((SIGN##32) DST CMP_OP (SIGN##32) IMM) { \
             insn += insn->off;          \
             CONT_JMP;               \
         }                       \
         CONT;
     COND_JMP(u, JEQ, ==)
     COND_JMP(u, JNE, !=)
     COND_JMP(u, JGT, >)
     COND_JMP(u, JLT, <)
     COND_JMP(u, JGE, >=)
     COND_JMP(u, JLE, <=)
     COND_JMP(u, JSET, &)
     COND_JMP(s, JSGT, >)
     COND_JMP(s, JSLT, <)
     COND_JMP(s, JSGE, >=)
     COND_JMP(s, JSLE, <=)
 #undef COND_JMP
     /* ST, STX and LDX*/
     ST_NOSPEC:
         /* Speculation barrier for mitigating Speculative Store Bypass.
          * In case of arm64, we rely on the firmware mitigation as
          * controlled via the ssbd kernel parameter. Whenever the
          * mitigation is enabled, it works for all of the kernel code
          * with no need to provide any additional instructions here.
          * In case of x86, we use 'lfence' insn for mitigation. We
          * reuse preexisting logic from Spectre v1 mitigation that
          * happens to produce the required code on x86 for v4 as well.
          */
 #ifdef CONFIG_X86
         barrier_nospec();
 #endif
         CONT;
 #define LDST(SIZEOP, SIZE)                      \
     STX_MEM_##SIZEOP:                       \
         *(SIZE *)(unsigned long) (DST + insn->off) = SRC;   \
         CONT;                           \
     ST_MEM_##SIZEOP:                        \
         *(SIZE *)(unsigned long) (DST + insn->off) = IMM;   \
         CONT;                           \
     LDX_MEM_##SIZEOP:                       \
         DST = *(SIZE *)(unsigned long) (SRC + insn->off);   \
         CONT;                           \
     LDX_PROBE_MEM_##SIZEOP:                     \
         bpf_probe_read_kernel(&DST, sizeof(SIZE),       \
                       (const void *)(long) (SRC + insn->off));  \
         DST = *((SIZE *)&DST);                  \
         CONT;
 
     LDST(B,   u8)
     LDST(H,  u16)
     LDST(W,  u32)
     LDST(DW, u64)
 #undef LDST
 
 #define ATOMIC_ALU_OP(BOP, KOP)                     \
         case BOP:                       \
             if (BPF_SIZE(insn->code) == BPF_W)      \
                 atomic_##KOP((u32) SRC, (atomic_t *)(unsigned long) \
                          (DST + insn->off));    \
             else                        \
                 atomic64_##KOP((u64) SRC, (atomic64_t *)(unsigned long) \
                            (DST + insn->off));  \
             break;                      \
         case BOP | BPF_FETCH:                   \
             if (BPF_SIZE(insn->code) == BPF_W)      \
                 SRC = (u32) atomic_fetch_##KOP(     \
                     (u32) SRC,          \
                     (atomic_t *)(unsigned long) (DST + insn->off)); \
             else                        \
                 SRC = (u64) atomic64_fetch_##KOP(   \
                     (u64) SRC,          \
                     (atomic64_t *)(unsigned long) (DST + insn->off)); \
             break;
 
     STX_ATOMIC_DW:
     STX_ATOMIC_W:
         switch (IMM) {
         ATOMIC_ALU_OP(BPF_ADD, add)
         ATOMIC_ALU_OP(BPF_AND, and)
         ATOMIC_ALU_OP(BPF_OR, or)
         ATOMIC_ALU_OP(BPF_XOR, xor)
 #undef ATOMIC_ALU_OP
 
         case BPF_XCHG:
             if (BPF_SIZE(insn->code) == BPF_W)
                 SRC = (u32) atomic_xchg(
                     (atomic_t *)(unsigned long) (DST + insn->off),
                     (u32) SRC);
             else
                 SRC = (u64) atomic64_xchg(
                     (atomic64_t *)(unsigned long) (DST + insn->off),
                     (u64) SRC);
             break;
         case BPF_CMPXCHG:
             if (BPF_SIZE(insn->code) == BPF_W)
                 BPF_R0 = (u32) atomic_cmpxchg(
                     (atomic_t *)(unsigned long) (DST + insn->off),
                     (u32) BPF_R0, (u32) SRC);
             else
                 BPF_R0 = (u64) atomic64_cmpxchg(
                     (atomic64_t *)(unsigned long) (DST + insn->off),
                     (u64) BPF_R0, (u64) SRC);
             break;
 
         default:
             goto default_label;
         }
         CONT;
 
     default_label:
         /* If we ever reach this, we have a bug somewhere. Die hard here
          * instead of just returning 0; we could be somewhere in a subprog,
          * so execution could continue otherwise which we do /not/ want.
          *
          * Note, verifier whitelists all opcodes in bpf_opcode_in_insntable().
          */
         pr_warn("BPF interpreter: unknown opcode %02x (imm: 0x%x)\n",
             insn->code, insn->imm);
         BUG_ON(1);
         return 0;
 }
 
 #define PROG_NAME(stack_size) __bpf_prog_run##stack_size
 #define DEFINE_BPF_PROG_RUN(stack_size) \
 static unsigned int PROG_NAME(stack_size)(const void *ctx, const struct bpf_insn *insn) \
 { \
     u64 stack[stack_size / sizeof(u64)]; \
     u64 regs[MAX_BPF_EXT_REG]; \
 \
     FP = (u64) (unsigned long) &stack[ARRAY_SIZE(stack)]; \
     ARG1 = (u64) (unsigned long) ctx; \
     return ___bpf_prog_run(regs, insn); \
 }
 
 #define PROG_NAME_ARGS(stack_size) __bpf_prog_run_args##stack_size
 #define DEFINE_BPF_PROG_RUN_ARGS(stack_size) \
 static u64 PROG_NAME_ARGS(stack_size)(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5, \
                       const struct bpf_insn *insn) \
 { \
     u64 stack[stack_size / sizeof(u64)]; \
     u64 regs[MAX_BPF_EXT_REG]; \
 \
     FP = (u64) (unsigned long) &stack[ARRAY_SIZE(stack)]; \
     BPF_R1 = r1; \
     BPF_R2 = r2; \
     BPF_R3 = r3; \
     BPF_R4 = r4; \
     BPF_R5 = r5; \
     return ___bpf_prog_run(regs, insn); \
 }
 
 #define EVAL1(FN, X) FN(X)
 #define EVAL2(FN, X, Y...) FN(X) EVAL1(FN, Y)
 #define EVAL3(FN, X, Y...) FN(X) EVAL2(FN, Y)
 #define EVAL4(FN, X, Y...) FN(X) EVAL3(FN, Y)
 #define EVAL5(FN, X, Y...) FN(X) EVAL4(FN, Y)
 #define EVAL6(FN, X, Y...) FN(X) EVAL5(FN, Y)
 
 EVAL6(DEFINE_BPF_PROG_RUN, 32, 64, 96, 128, 160, 192);
 EVAL6(DEFINE_BPF_PROG_RUN, 224, 256, 288, 320, 352, 384);
 EVAL4(DEFINE_BPF_PROG_RUN, 416, 448, 480, 512);
 
 EVAL6(DEFINE_BPF_PROG_RUN_ARGS, 32, 64, 96, 128, 160, 192);
 EVAL6(DEFINE_BPF_PROG_RUN_ARGS, 224, 256, 288, 320, 352, 384);
 EVAL4(DEFINE_BPF_PROG_RUN_ARGS, 416, 448, 480, 512);
 
 #define PROG_NAME_LIST(stack_size) PROG_NAME(stack_size),
 
 static unsigned int (*interpreters[])(const void *ctx,
                       const struct bpf_insn *insn) = {
 EVAL6(PROG_NAME_LIST, 32, 64, 96, 128, 160, 192)
 EVAL6(PROG_NAME_LIST, 224, 256, 288, 320, 352, 384)
 EVAL4(PROG_NAME_LIST, 416, 448, 480, 512)
 };
 #undef PROG_NAME_LIST
 #define PROG_NAME_LIST(stack_size) PROG_NAME_ARGS(stack_size),
 static u64 (*interpreters_args[])(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5,
                   const struct bpf_insn *insn) = {
 EVAL6(PROG_NAME_LIST, 32, 64, 96, 128, 160, 192)
 EVAL6(PROG_NAME_LIST, 224, 256, 288, 320, 352, 384)
 EVAL4(PROG_NAME_LIST, 416, 448, 480, 512)
 };
 #undef PROG_NAME_LIST
 
 void bpf_patch_call_args(struct bpf_insn *insn, u32 stack_depth)
 {
     stack_depth = max_t(u32, stack_depth, 1);
     insn->off = (s16) insn->imm;
     insn->imm = interpreters_args[(round_up(stack_depth, 32) / 32) - 1] -
         __bpf_call_base_args;
     insn->code = BPF_JMP | BPF_CALL_ARGS;
 }
 
 #else
 static unsigned int __bpf_prog_ret0_warn(const void *ctx,
                      const struct bpf_insn *insn)
 {
     /* If this handler ever gets executed, then BPF_JIT_ALWAYS_ON
      * is not working properly, so warn about it!
      */
     WARN_ON_ONCE(1);
     return 0;
 }
 #endif
 
 bool bpf_prog_map_compatible(struct bpf_map *map,
                  const struct bpf_prog *fp)
 {
     bool ret;
 
     if (fp->kprobe_override)
         return false;
 
     spin_lock(&map->owner.lock);
     if (!map->owner.type) {
         /* There's no owner yet where we could check for
          * compatibility.
          */
         map->owner.type  = fp->type;
         map->owner.jited = fp->jited;
         map->owner.xdp_has_frags = fp->aux->xdp_has_frags;
         ret = true;
     } else {
         ret = map->owner.type  == fp->type &&
               map->owner.jited == fp->jited &&
               map->owner.xdp_has_frags == fp->aux->xdp_has_frags;
     }
     spin_unlock(&map->owner.lock);
 
     return ret;
 }
 
 static int bpf_check_tail_call(const struct bpf_prog *fp)
 {
     struct bpf_prog_aux *aux = fp->aux;
     int i, ret = 0;
 
     mutex_lock(&aux->used_maps_mutex);
     for (i = 0; i < aux->used_map_cnt; i++) {
         struct bpf_map *map = aux->used_maps[i];
 
         if (!map_type_contains_progs(map))
             continue;
 
         if (!bpf_prog_map_compatible(map, fp)) {
             ret = -EINVAL;
             goto out;
         }
     }
 
 out:
     mutex_unlock(&aux->used_maps_mutex);
     return ret;
 }
 
 static void bpf_prog_select_func(struct bpf_prog *fp)
 {
 #ifndef CONFIG_BPF_JIT_ALWAYS_ON
     u32 stack_depth = max_t(u32, fp->aux->stack_depth, 1);
 
     fp->bpf_func = interpreters[(round_up(stack_depth, 32) / 32) - 1];
 #else
     fp->bpf_func = __bpf_prog_ret0_warn;
 #endif
 }
 
 /**
  *  bpf_prog_select_runtime - select exec runtime for BPF program
  *  @fp: bpf_prog populated with BPF program
  *  @err: pointer to error variable
  *
  * Try to JIT eBPF program, if JIT is not available, use interpreter.
  * The BPF program will be executed via bpf_prog_run() function.
  *
  * Return: the &fp argument along with &err set to 0 for success or
  * a negative errno code on failure
  */
 struct bpf_prog *bpf_prog_select_runtime(struct bpf_prog *fp, int *err)
 {
     /* In case of BPF to BPF calls, verifier did all the prep
      * work with regards to JITing, etc.
      */
     bool jit_needed = false;
 
     if (fp->bpf_func)
         goto finalize;
 
     if (IS_ENABLED(CONFIG_BPF_JIT_ALWAYS_ON) ||
         bpf_prog_has_kfunc_call(fp))
         jit_needed = true;
 
     bpf_prog_select_func(fp);
 
     /* eBPF JITs can rewrite the program in case constant
      * blinding is active. However, in case of error during
      * blinding, bpf_int_jit_compile() must always return a
      * valid program, which in this case would simply not
      * be JITed, but falls back to the interpreter.
      */
     if (!bpf_prog_is_dev_bound(fp->aux)) {
         *err = bpf_prog_alloc_jited_linfo(fp);
         if (*err)
             return fp;
 
         fp = bpf_int_jit_compile(fp);
         bpf_prog_jit_attempt_done(fp);
         if (!fp->jited && jit_needed) {
             *err = -ENOTSUPP;
             return fp;
         }
     } else {
         *err = bpf_prog_offload_compile(fp);
         if (*err)
             return fp;
     }
 
 finalize:
     bpf_prog_lock_ro(fp);
 
     /* The tail call compatibility check can only be done at
      * this late stage as we need to determine, if we deal
      * with JITed or non JITed program concatenations and not
      * all eBPF JITs might immediately support all features.
      */
     *err = bpf_check_tail_call(fp);
 
     return fp;
 }
 EXPORT_SYMBOL_GPL(bpf_prog_select_runtime);
 
 static unsigned int __bpf_prog_ret1(const void *ctx,
                     const struct bpf_insn *insn)
 {
     return 1;
 }
 
 static struct bpf_prog_dummy {
     struct bpf_prog prog;
 } dummy_bpf_prog = {
     .prog = {
         .bpf_func = __bpf_prog_ret1,
     },
 };
 
 struct bpf_empty_prog_array bpf_empty_prog_array = {
     .null_prog = NULL,
 };
 EXPORT_SYMBOL(bpf_empty_prog_array);
 
 struct bpf_prog_array *bpf_prog_array_alloc(u32 prog_cnt, gfp_t flags)
 {
     if (prog_cnt)
         return kzalloc(sizeof(struct bpf_prog_array) +
                    sizeof(struct bpf_prog_array_item) *
                    (prog_cnt + 1),
                    flags);
 
     return &bpf_empty_prog_array.hdr;
 }
 
 void bpf_prog_array_free(struct bpf_prog_array *progs)
 {
     if (!progs || progs == &bpf_empty_prog_array.hdr)
         return;
     kfree_rcu(progs, rcu);
 }
 
 static void __bpf_prog_array_free_sleepable_cb(struct rcu_head *rcu)
 {
     struct bpf_prog_array *progs;
 
     progs = container_of(rcu, struct bpf_prog_array, rcu);
     kfree_rcu(progs, rcu);
 }
 
 void bpf_prog_array_free_sleepable(struct bpf_prog_array *progs)
 {
     if (!progs || progs == &bpf_empty_prog_array.hdr)
         return;
     call_rcu_tasks_trace(&progs->rcu, __bpf_prog_array_free_sleepable_cb);
 }
 
 int bpf_prog_array_length(struct bpf_prog_array *array)
 {
     struct bpf_prog_array_item *item;
     u32 cnt = 0;
 
     for (item = array->items; item->prog; item++)
         if (item->prog != &dummy_bpf_prog.prog)
             cnt++;
     return cnt;
 }
 
 bool bpf_prog_array_is_empty(struct bpf_prog_array *array)
 {
     struct bpf_prog_array_item *item;
 
     for (item = array->items; item->prog; item++)
         if (item->prog != &dummy_bpf_prog.prog)
             return false;
     return true;
 }
 
 static bool bpf_prog_array_copy_core(struct bpf_prog_array *array,
                      u32 *prog_ids,
                      u32 request_cnt)
 {
     struct bpf_prog_array_item *item;
     int i = 0;
 
     for (item = array->items; item->prog; item++) {
         if (item->prog == &dummy_bpf_prog.prog)
             continue;
         prog_ids[i] = item->prog->aux->id;
         if (++i == request_cnt) {
             item++;
             break;
         }
     }
 
     return !!(item->prog);
 }
 
 int bpf_prog_array_copy_to_user(struct bpf_prog_array *array,
                 __u32 __user *prog_ids, u32 cnt)
 {
     unsigned long err = 0;
     bool nospc;
     u32 *ids;
 
     /* users of this function are doing:
      * cnt = bpf_prog_array_length();
      * if (cnt > 0)
      *     bpf_prog_array_copy_to_user(..., cnt);
      * so below kcalloc doesn't need extra cnt > 0 check.
      */
     ids = kcalloc(cnt, sizeof(u32), GFP_USER | __GFP_NOWARN);
     if (!ids)
         return -ENOMEM;
     nospc = bpf_prog_array_copy_core(array, ids, cnt);
     err = copy_to_user(prog_ids, ids, cnt * sizeof(u32));
     kfree(ids);
     if (err)
         return -EFAULT;
     if (nospc)
         return -ENOSPC;
     return 0;
 }
 
 void bpf_prog_array_delete_safe(struct bpf_prog_array *array,
                 struct bpf_prog *old_prog)
 {
     struct bpf_prog_array_item *item;
 
     for (item = array->items; item->prog; item++)
         if (item->prog == old_prog) {
             WRITE_ONCE(item->prog, &dummy_bpf_prog.prog);
             break;
         }
 }
 
 /**
  * bpf_prog_array_delete_safe_at() - Replaces the program at the given
  *                                   index into the program array with
  *                                   a dummy no-op program.
  * @array: a bpf_prog_array
  * @index: the index of the program to replace
  *
  * Skips over dummy programs, by not counting them, when calculating
  * the position of the program to replace.
  *
  * Return:
  * * 0      - Success
  * * -EINVAL    - Invalid index value. Must be a non-negative integer.
  * * -ENOENT    - Index out of range
  */
 int bpf_prog_array_delete_safe_at(struct bpf_prog_array *array, int index)
 {
     return bpf_prog_array_update_at(array, index, &dummy_bpf_prog.prog);
 }
 
 /**
  * bpf_prog_array_update_at() - Updates the program at the given index
  *                              into the program array.
  * @array: a bpf_prog_array
  * @index: the index of the program to update
  * @prog: the program to insert into the array
  *
  * Skips over dummy programs, by not counting them, when calculating
  * the position of the program to update.
  *
  * Return:
  * * 0      - Success
  * * -EINVAL    - Invalid index value. Must be a non-negative integer.
  * * -ENOENT    - Index out of range
  */
 int bpf_prog_array_update_at(struct bpf_prog_array *array, int index,
                  struct bpf_prog *prog)
 {
     struct bpf_prog_array_item *item;
 
     if (unlikely(index < 0))
         return -EINVAL;
 
     for (item = array->items; item->prog; item++) {
         if (item->prog == &dummy_bpf_prog.prog)
             continue;
         if (!index) {
             WRITE_ONCE(item->prog, prog);
             return 0;
         }
         index--;
     }
     return -ENOENT;
 }
 
 int bpf_prog_array_copy(struct bpf_prog_array *old_array,
             struct bpf_prog *exclude_prog,
             struct bpf_prog *include_prog,
             u64 bpf_cookie,
             struct bpf_prog_array **new_array)
 {
     int new_prog_cnt, carry_prog_cnt = 0;
     struct bpf_prog_array_item *existing, *new;
     struct bpf_prog_array *array;
     bool found_exclude = false;
 
     /* Figure out how many existing progs we need to carry over to
      * the new array.
      */
     if (old_array) {
         existing = old_array->items;
         for (; existing->prog; existing++) {
             if (existing->prog == exclude_prog) {
                 found_exclude = true;
                 continue;
             }
             if (existing->prog != &dummy_bpf_prog.prog)
                 carry_prog_cnt++;
             if (existing->prog == include_prog)
                 return -EEXIST;
         }
     }
 
     if (exclude_prog && !found_exclude)
         return -ENOENT;
 
     /* How many progs (not NULL) will be in the new array? */
     new_prog_cnt = carry_prog_cnt;
     if (include_prog)
         new_prog_cnt += 1;
 
     /* Do we have any prog (not NULL) in the new array? */
     if (!new_prog_cnt) {
         *new_array = NULL;
         return 0;
     }
 
     /* +1 as the end of prog_array is marked with NULL */
     array = bpf_prog_array_alloc(new_prog_cnt + 1, GFP_KERNEL);
     if (!array)
         return -ENOMEM;
     new = array->items;
 
     /* Fill in the new prog array */
     if (carry_prog_cnt) {
         existing = old_array->items;
         for (; existing->prog; existing++) {
             if (existing->prog == exclude_prog ||
                 existing->prog == &dummy_bpf_prog.prog)
                 continue;
 
             new->prog = existing->prog;
             new->bpf_cookie = existing->bpf_cookie;
             new++;
         }
     }
     if (include_prog) {
         new->prog = include_prog;
         new->bpf_cookie = bpf_cookie;
         new++;
     }
     new->prog = NULL;
     *new_array = array;
     return 0;
 }
 
 int bpf_prog_array_copy_info(struct bpf_prog_array *array,
                  u32 *prog_ids, u32 request_cnt,
                  u32 *prog_cnt)
 {
     u32 cnt = 0;
 
     if (array)
         cnt = bpf_prog_array_length(array);
 
     *prog_cnt = cnt;
 
     /* return early if user requested only program count or nothing to copy */
     if (!request_cnt || !cnt)
         return 0;
 
     /* this function is called under trace/bpf_trace.c: bpf_event_mutex */
     return bpf_prog_array_copy_core(array, prog_ids, request_cnt) ? -ENOSPC
                                      : 0;
 }
 
 void __bpf_free_used_maps(struct bpf_prog_aux *aux,
               struct bpf_map **used_maps, u32 len)
 {
     struct bpf_map *map;
     u32 i;
 
     for (i = 0; i < len; i++) {
         map = used_maps[i];
         if (map->ops->map_poke_untrack)
             map->ops->map_poke_untrack(map, aux);
         bpf_map_put(map);
     }
 }
 
 static void bpf_free_used_maps(struct bpf_prog_aux *aux)
 {
     __bpf_free_used_maps(aux, aux->used_maps, aux->used_map_cnt);
     kfree(aux->used_maps);
 }
 
 void __bpf_free_used_btfs(struct bpf_prog_aux *aux,
               struct btf_mod_pair *used_btfs, u32 len)
 {
 #ifdef CONFIG_BPF_SYSCALL
     struct btf_mod_pair *btf_mod;
     u32 i;
 
     for (i = 0; i < len; i++) {
         btf_mod = &used_btfs[i];
         if (btf_mod->module)
             module_put(btf_mod->module);
         btf_put(btf_mod->btf);
     }
 #endif
 }
 
 static void bpf_free_used_btfs(struct bpf_prog_aux *aux)
 {
     __bpf_free_used_btfs(aux, aux->used_btfs, aux->used_btf_cnt);
     kfree(aux->used_btfs);
 }
 
 static void bpf_prog_free_deferred(struct work_struct *work)
 {
     struct bpf_prog_aux *aux;
     int i;
 
     aux = container_of(work, struct bpf_prog_aux, work);
 #ifdef CONFIG_BPF_SYSCALL
     bpf_free_kfunc_btf_tab(aux->kfunc_btf_tab);
 #endif
 #ifdef CONFIG_CGROUP_BPF
     if (aux->cgroup_atype != CGROUP_BPF_ATTACH_TYPE_INVALID)
         bpf_cgroup_atype_put(aux->cgroup_atype);
 #endif
     bpf_free_used_maps(aux);
     bpf_free_used_btfs(aux);
     if (bpf_prog_is_dev_bound(aux))
         bpf_prog_offload_destroy(aux->prog);
 #ifdef CONFIG_PERF_EVENTS
     if (aux->prog->has_callchain_buf)
         put_callchain_buffers();
 #endif
     if (aux->dst_trampoline)
         bpf_trampoline_put(aux->dst_trampoline);
     for (i = 0; i < aux->func_cnt; i++) {
         /* We can just unlink the subprog poke descriptor table as
          * it was originally linked to the main program and is also
          * released along with it.
          */
         aux->func[i]->aux->poke_tab = NULL;
         bpf_jit_free(aux->func[i]);
     }
     if (aux->func_cnt) {
         kfree(aux->func);
         bpf_prog_unlock_free(aux->prog);
     } else {
         bpf_jit_free(aux->prog);
     }
 }
 
 void bpf_prog_free(struct bpf_prog *fp)
 {
     struct bpf_prog_aux *aux = fp->aux;
 
     if (aux->dst_prog)
         bpf_prog_put(aux->dst_prog);
     INIT_WORK(&aux->work, bpf_prog_free_deferred);
     schedule_work(&aux->work);
 }
 EXPORT_SYMBOL_GPL(bpf_prog_free);
 
 /* RNG for unpriviledged user space with separated state from prandom_u32(). */
 static DEFINE_PER_CPU(struct rnd_state, bpf_user_rnd_state);
 
 void bpf_user_rnd_init_once(void)
 {
     prandom_init_once(&bpf_user_rnd_state);
 }
 
 BPF_CALL_0(bpf_user_rnd_u32)
 {
     /* Should someone ever have the rather unwise idea to use some
      * of the registers passed into this function, then note that
      * this function is called from native eBPF and classic-to-eBPF
      * transformations. Register assignments from both sides are
      * different, f.e. classic always sets fn(ctx, A, X) here.
      */
     struct rnd_state *state;
     u32 res;
 
     state = &get_cpu_var(bpf_user_rnd_state);
     res = prandom_u32_state(state);
     put_cpu_var(bpf_user_rnd_state);
 
     return res;
 }
 
 BPF_CALL_0(bpf_get_raw_cpu_id)
 {
     return raw_smp_processor_id();
 }
 
 /* Weak definitions of helper functions in case we don't have bpf syscall. */
 const struct bpf_func_proto bpf_map_lookup_elem_proto __weak;
 const struct bpf_func_proto bpf_map_update_elem_proto __weak;
 const struct bpf_func_proto bpf_map_delete_elem_proto __weak;
 const struct bpf_func_proto bpf_map_push_elem_proto __weak;
 const struct bpf_func_proto bpf_map_pop_elem_proto __weak;
 const struct bpf_func_proto bpf_map_peek_elem_proto __weak;
 const struct bpf_func_proto bpf_map_lookup_percpu_elem_proto __weak;
 const struct bpf_func_proto bpf_spin_lock_proto __weak;
 const struct bpf_func_proto bpf_spin_unlock_proto __weak;
 const struct bpf_func_proto bpf_jiffies64_proto __weak;
 
 const struct bpf_func_proto bpf_get_prandom_u32_proto __weak;
 const struct bpf_func_proto bpf_get_smp_processor_id_proto __weak;
 const struct bpf_func_proto bpf_get_numa_node_id_proto __weak;
 const struct bpf_func_proto bpf_ktime_get_ns_proto __weak;
 const struct bpf_func_proto bpf_ktime_get_boot_ns_proto __weak;
 const struct bpf_func_proto bpf_ktime_get_coarse_ns_proto __weak;
 
 const struct bpf_func_proto bpf_get_current_pid_tgid_proto __weak;
 const struct bpf_func_proto bpf_get_current_uid_gid_proto __weak;
 const struct bpf_func_proto bpf_get_current_comm_proto __weak;
 const struct bpf_func_proto bpf_get_current_cgroup_id_proto __weak;
 const struct bpf_func_proto bpf_get_current_ancestor_cgroup_id_proto __weak;
 const struct bpf_func_proto bpf_get_local_storage_proto __weak;
 const struct bpf_func_proto bpf_get_ns_current_pid_tgid_proto __weak;
 const struct bpf_func_proto bpf_snprintf_btf_proto __weak;
 const struct bpf_func_proto bpf_seq_printf_btf_proto __weak;
 const struct bpf_func_proto bpf_set_retval_proto __weak;
 const struct bpf_func_proto bpf_get_retval_proto __weak;
 
 const struct bpf_func_proto * __weak bpf_get_trace_printk_proto(void)
 {
     return NULL;
 }
 
 const struct bpf_func_proto * __weak bpf_get_trace_vprintk_proto(void)
 {
     return NULL;
 }
 
 u64 __weak
 bpf_event_output(struct bpf_map *map, u64 flags, void *meta, u64 meta_size,
          void *ctx, u64 ctx_size, bpf_ctx_copy_t ctx_copy)
 {
     return -ENOTSUPP;
 }
 EXPORT_SYMBOL_GPL(bpf_event_output);
 
 /* Always built-in helper functions. */
 const struct bpf_func_proto bpf_tail_call_proto = {
     .func       = NULL,
     .gpl_only   = false,
     .ret_type   = RET_VOID,
     .arg1_type  = ARG_PTR_TO_CTX,
     .arg2_type  = ARG_CONST_MAP_PTR,
     .arg3_type  = ARG_ANYTHING,
 };
 
 /* Stub for JITs that only support cBPF. eBPF programs are interpreted.
  * It is encouraged to implement bpf_int_jit_compile() instead, so that
  * eBPF and implicitly also cBPF can get JITed!
  */
 struct bpf_prog * __weak bpf_int_jit_compile(struct bpf_prog *prog)
 {
     return prog;
 }
 
 /* Stub for JITs that support eBPF. All cBPF code gets transformed into
  * eBPF by the kernel and is later compiled by bpf_int_jit_compile().
  */
 void __weak bpf_jit_compile(struct bpf_prog *prog)
 {
 }
 
 bool __weak bpf_helper_changes_pkt_data(void *func)
 {
     return false;
 }
 
 /* Return TRUE if the JIT backend wants verifier to enable sub-register usage
  * analysis code and wants explicit zero extension inserted by verifier.
  * Otherwise, return FALSE.
  *
  * The verifier inserts an explicit zero extension after BPF_CMPXCHGs even if
  * you don't override this. JITs that don't want these extra insns can detect
  * them using insn_is_zext.
  */
 bool __weak bpf_jit_needs_zext(void)
 {
     return false;
 }
 
 /* Return TRUE if the JIT backend supports mixing bpf2bpf and tailcalls. */
 bool __weak bpf_jit_supports_subprog_tailcalls(void)
 {
     return false;
 }
 
 bool __weak bpf_jit_supports_kfunc_call(void)
 {
     return false;
 }
 
 /* To execute LD_ABS/LD_IND instructions __bpf_prog_run() may call
  * skb_copy_bits(), so provide a weak definition of it for NET-less config.
  */
 int __weak skb_copy_bits(const struct sk_buff *skb, int offset, void *to,
              int len)
 {
     return -EFAULT;
 }
 
 int __weak bpf_arch_text_poke(void *ip, enum bpf_text_poke_type t,
                   void *addr1, void *addr2)
 {
     return -ENOTSUPP;
 }
 
 void * __weak bpf_arch_text_copy(void *dst, void *src, size_t len)
 {
     return ERR_PTR(-ENOTSUPP);
 }
 
 int __weak bpf_arch_text_invalidate(void *dst, size_t len)
 {
     return -ENOTSUPP;
 }
 
 DEFINE_STATIC_KEY_FALSE(bpf_stats_enabled_key);
 EXPORT_SYMBOL(bpf_stats_enabled_key);
 
 /* All definitions of tracepoints related to BPF. */
 #define CREATE_TRACE_POINTS
 #include <linux/bpf_trace.h>
 
 EXPORT_TRACEPOINT_SYMBOL_GPL(xdp_exception);
 EXPORT_TRACEPOINT_SYMBOL_GPL(xdp_bulk_tx);