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- /*
- * 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>
- *
- * This program is free software; you can redistribute it and/or
- * modify it under the terms of the GNU General Public License
- * as published by the Free Software Foundation; either version
- * 2 of the License, or (at your option) any later version.
- *
- * Andi Kleen - Fix a few bad bugs and races.
- * Kris Katterjohn - Added many additional checks in bpf_check_classic()
- */
- #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/frame.h>
- #include <linux/rbtree_latch.h>
- #include <linux/kallsyms.h>
- #include <linux/rcupdate.h>
- #include <linux/perf_event.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)
- 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(unsigned int size, gfp_t gfp_extra_flags)
- {
- gfp_t gfp_flags = GFP_KERNEL | __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, PAGE_KERNEL);
- if (fp == NULL)
- return NULL;
- aux = kzalloc(sizeof(*aux), GFP_KERNEL | gfp_extra_flags);
- if (aux == NULL) {
- vfree(fp);
- return NULL;
- }
- fp->pages = size / PAGE_SIZE;
- fp->aux = aux;
- fp->aux->prog = fp;
- fp->jit_requested = ebpf_jit_enabled();
- INIT_LIST_HEAD_RCU(&fp->aux->ksym_lnode);
- return fp;
- }
- EXPORT_SYMBOL_GPL(bpf_prog_alloc);
- 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 | __GFP_ZERO | gfp_extra_flags;
- struct bpf_prog *fp;
- u32 pages, delta;
- int ret;
- BUG_ON(fp_old == NULL);
- size = round_up(size, PAGE_SIZE);
- pages = size / PAGE_SIZE;
- if (pages <= fp_old->pages)
- return fp_old;
- delta = pages - fp_old->pages;
- ret = __bpf_prog_charge(fp_old->aux->user, delta);
- if (ret)
- return NULL;
- fp = __vmalloc(size, gfp_flags, PAGE_KERNEL);
- if (fp == NULL) {
- __bpf_prog_uncharge(fp_old->aux->user, delta);
- } else {
- 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;
- __bpf_prog_free(fp_old);
- }
- return fp;
- }
- void __bpf_prog_free(struct bpf_prog *fp)
- {
- kfree(fp->aux);
- vfree(fp);
- }
- int bpf_prog_calc_tag(struct bpf_prog *fp)
- {
- const u32 bits_offset = SHA_MESSAGE_BYTES - sizeof(__be64);
- u32 raw_size = bpf_prog_tag_scratch_size(fp);
- u32 digest[SHA_DIGEST_WORDS];
- u32 ws[SHA_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;
- sha_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) {
- 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, SHA_MESSAGE_BYTES);
- blocks = bsize / SHA_MESSAGE_BYTES;
- 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--) {
- sha_transform(digest, todo, ws);
- todo += SHA_MESSAGE_BYTES;
- }
- result = (__force __be32 *)digest;
- for (i = 0; i < SHA_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, u32 delta,
- u32 curr, const bool probe_pass)
- {
- const s64 imm_min = S32_MIN, imm_max = S32_MAX;
- s64 imm = insn->imm;
- if (curr < pos && curr + imm + 1 > pos)
- imm += delta;
- else if (curr > pos + delta && curr + imm + 1 <= pos + delta)
- 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, u32 delta,
- u32 curr, const bool probe_pass)
- {
- const s32 off_min = S16_MIN, off_max = S16_MAX;
- s32 off = insn->off;
- if (curr < pos && curr + off + 1 > pos)
- off += delta;
- else if (curr > pos + delta && curr + off + 1 <= pos + delta)
- 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, u32 delta,
- const bool probe_pass)
- {
- u32 i, insn_cnt = prog->len + (probe_pass ? delta : 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 += delta + 1;
- insn++;
- }
- code = insn->code;
- if (BPF_CLASS(code) != BPF_JMP ||
- 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, delta, i,
- probe_pass);
- } else {
- ret = bpf_adj_delta_to_off(insn, pos, delta, i,
- probe_pass);
- }
- if (ret)
- break;
- }
- return ret;
- }
- 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;
- /* 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 &&
- bpf_adj_branches(prog, off, insn_delta, true))
- return NULL;
- /* 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 NULL;
- 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, insn_delta, false));
- return prog_adj;
- }
- 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_ALWAYS_ON);
- int bpf_jit_harden __read_mostly;
- int bpf_jit_kallsyms __read_mostly;
- long bpf_jit_limit __read_mostly;
- static __always_inline void
- bpf_get_prog_addr_region(const struct bpf_prog *prog,
- unsigned long *symbol_start,
- unsigned long *symbol_end)
- {
- const struct bpf_binary_header *hdr = bpf_jit_binary_hdr(prog);
- unsigned long addr = (unsigned long)hdr;
- WARN_ON_ONCE(!bpf_prog_ebpf_jited(prog));
- *symbol_start = addr;
- *symbol_end = addr + hdr->pages * PAGE_SIZE;
- }
- static void bpf_get_prog_name(const struct bpf_prog *prog, char *sym)
- {
- const char *end = sym + KSYM_NAME_LEN;
- 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));
- if (prog->aux->name[0])
- snprintf(sym, (size_t)(end - sym), "_%s", prog->aux->name);
- else
- *sym = 0;
- }
- static __always_inline unsigned long
- bpf_get_prog_addr_start(struct latch_tree_node *n)
- {
- unsigned long symbol_start, symbol_end;
- const struct bpf_prog_aux *aux;
- aux = container_of(n, struct bpf_prog_aux, ksym_tnode);
- bpf_get_prog_addr_region(aux->prog, &symbol_start, &symbol_end);
- return symbol_start;
- }
- static __always_inline bool bpf_tree_less(struct latch_tree_node *a,
- struct latch_tree_node *b)
- {
- return bpf_get_prog_addr_start(a) < bpf_get_prog_addr_start(b);
- }
- static __always_inline int bpf_tree_comp(void *key, struct latch_tree_node *n)
- {
- unsigned long val = (unsigned long)key;
- unsigned long symbol_start, symbol_end;
- const struct bpf_prog_aux *aux;
- aux = container_of(n, struct bpf_prog_aux, ksym_tnode);
- bpf_get_prog_addr_region(aux->prog, &symbol_start, &symbol_end);
- if (val < symbol_start)
- return -1;
- if (val >= symbol_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;
- static void bpf_prog_ksym_node_add(struct bpf_prog_aux *aux)
- {
- WARN_ON_ONCE(!list_empty(&aux->ksym_lnode));
- list_add_tail_rcu(&aux->ksym_lnode, &bpf_kallsyms);
- latch_tree_insert(&aux->ksym_tnode, &bpf_tree, &bpf_tree_ops);
- }
- static void bpf_prog_ksym_node_del(struct bpf_prog_aux *aux)
- {
- if (list_empty(&aux->ksym_lnode))
- return;
- latch_tree_erase(&aux->ksym_tnode, &bpf_tree, &bpf_tree_ops);
- list_del_rcu(&aux->ksym_lnode);
- }
- static bool bpf_prog_kallsyms_candidate(const struct bpf_prog *fp)
- {
- return fp->jited && !bpf_prog_was_classic(fp);
- }
- static bool bpf_prog_kallsyms_verify_off(const struct bpf_prog *fp)
- {
- return list_empty(&fp->aux->ksym_lnode) ||
- fp->aux->ksym_lnode.prev == LIST_POISON2;
- }
- void bpf_prog_kallsyms_add(struct bpf_prog *fp)
- {
- if (!bpf_prog_kallsyms_candidate(fp) ||
- !capable(CAP_SYS_ADMIN))
- return;
- spin_lock_bh(&bpf_lock);
- bpf_prog_ksym_node_add(fp->aux);
- spin_unlock_bh(&bpf_lock);
- }
- void bpf_prog_kallsyms_del(struct bpf_prog *fp)
- {
- if (!bpf_prog_kallsyms_candidate(fp))
- return;
- spin_lock_bh(&bpf_lock);
- bpf_prog_ksym_node_del(fp->aux);
- spin_unlock_bh(&bpf_lock);
- }
- static struct bpf_prog *bpf_prog_kallsyms_find(unsigned long addr)
- {
- struct latch_tree_node *n;
- if (!bpf_jit_kallsyms_enabled())
- return NULL;
- n = latch_tree_find((void *)addr, &bpf_tree, &bpf_tree_ops);
- return n ?
- container_of(n, struct bpf_prog_aux, ksym_tnode)->prog :
- NULL;
- }
- const char *__bpf_address_lookup(unsigned long addr, unsigned long *size,
- unsigned long *off, char *sym)
- {
- unsigned long symbol_start, symbol_end;
- struct bpf_prog *prog;
- char *ret = NULL;
- rcu_read_lock();
- prog = bpf_prog_kallsyms_find(addr);
- if (prog) {
- bpf_get_prog_addr_region(prog, &symbol_start, &symbol_end);
- bpf_get_prog_name(prog, sym);
- 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_prog_kallsyms_find(addr) != NULL;
- rcu_read_unlock();
- return ret;
- }
- int bpf_get_kallsym(unsigned int symnum, unsigned long *value, char *type,
- char *sym)
- {
- unsigned long symbol_start, symbol_end;
- struct bpf_prog_aux *aux;
- unsigned int it = 0;
- int ret = -ERANGE;
- if (!bpf_jit_kallsyms_enabled())
- return ret;
- rcu_read_lock();
- list_for_each_entry_rcu(aux, &bpf_kallsyms, ksym_lnode) {
- if (it++ != symnum)
- continue;
- bpf_get_prog_addr_region(aux->prog, &symbol_start, &symbol_end);
- bpf_get_prog_name(aux->prog, sym);
- *value = symbol_start;
- *type = BPF_SYM_ELF_TYPE;
- ret = 0;
- break;
- }
- rcu_read_unlock();
- return ret;
- }
- 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 = min_t(u64, round_up(bpf_jit_alloc_exec_limit() >> 2,
- PAGE_SIZE), LONG_MAX);
- return 0;
- }
- pure_initcall(bpf_jit_charge_init);
- static int bpf_jit_charge_modmem(u32 pages)
- {
- if (atomic_long_add_return(pages, &bpf_jit_current) >
- (bpf_jit_limit >> PAGE_SHIFT)) {
- if (!capable(CAP_SYS_ADMIN)) {
- atomic_long_sub(pages, &bpf_jit_current);
- return -EPERM;
- }
- }
- return 0;
- }
- static void bpf_jit_uncharge_modmem(u32 pages)
- {
- atomic_long_sub(pages, &bpf_jit_current);
- }
- 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, pages;
- /* 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);
- pages = size / PAGE_SIZE;
- if (bpf_jit_charge_modmem(pages))
- return NULL;
- hdr = module_alloc(size);
- if (!hdr) {
- bpf_jit_uncharge_modmem(pages);
- return NULL;
- }
- /* Fill space with illegal/arch-dep instructions. */
- bpf_fill_ill_insns(hdr, size);
- hdr->pages = pages;
- 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 pages = hdr->pages;
- module_memfree(hdr);
- bpf_jit_uncharge_modmem(pages);
- }
- /* 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_unlock_ro(hdr);
- bpf_jit_binary_free(hdr);
- WARN_ON_ONCE(!bpf_prog_kallsyms_verify_off(fp));
- }
- bpf_prog_unlock_free(fp);
- }
- static int bpf_jit_blind_insn(const struct bpf_insn *from,
- const struct bpf_insn *aux,
- struct bpf_insn *to_buff)
- {
- 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_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);
- *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, PAGE_KERNEL);
- 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;
- __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 (!bpf_jit_blinding_enabled(prog) || 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++) {
- /* 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);
- if (!rewritten)
- continue;
- tmp = bpf_patch_insn_single(clone, i, insn_buff, rewritten);
- if (!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 ERR_PTR(-ENOMEM);
- }
- 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, 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, 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), \
- /* 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, XADD, W), \
- INSN_3(STX, XADD, 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
- /**
- * __bpf_prog_run - run eBPF program on a given context
- * @ctx: is the data we are operating on
- * @insn: is the array of eBPF instructions
- *
- * Decode and execute eBPF instructions.
- */
- static u64 ___bpf_prog_run(u64 *regs, const struct bpf_insn *insn, u64 *stack)
- {
- #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 *jumptable[256] = {
- [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,
- };
- #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];
- /* ALU */
- #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(LSH, <<)
- ALU(RSH, >>)
- ALU(XOR, ^)
- ALU(MUL, *)
- #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;
- ALU64_ARSH_X:
- (*(s64 *) &DST) >>= SRC;
- 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
- * handeled 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 */
- JMP_JA:
- insn += insn->off;
- CONT;
- JMP_JEQ_X:
- if (DST == SRC) {
- insn += insn->off;
- CONT_JMP;
- }
- CONT;
- JMP_JEQ_K:
- if (DST == IMM) {
- insn += insn->off;
- CONT_JMP;
- }
- CONT;
- JMP_JNE_X:
- if (DST != SRC) {
- insn += insn->off;
- CONT_JMP;
- }
- CONT;
- JMP_JNE_K:
- if (DST != IMM) {
- insn += insn->off;
- CONT_JMP;
- }
- CONT;
- JMP_JGT_X:
- if (DST > SRC) {
- insn += insn->off;
- CONT_JMP;
- }
- CONT;
- JMP_JGT_K:
- if (DST > IMM) {
- insn += insn->off;
- CONT_JMP;
- }
- CONT;
- JMP_JLT_X:
- if (DST < SRC) {
- insn += insn->off;
- CONT_JMP;
- }
- CONT;
- JMP_JLT_K:
- if (DST < IMM) {
- insn += insn->off;
- CONT_JMP;
- }
- CONT;
- JMP_JGE_X:
- if (DST >= SRC) {
- insn += insn->off;
- CONT_JMP;
- }
- CONT;
- JMP_JGE_K:
- if (DST >= IMM) {
- insn += insn->off;
- CONT_JMP;
- }
- CONT;
- JMP_JLE_X:
- if (DST <= SRC) {
- insn += insn->off;
- CONT_JMP;
- }
- CONT;
- JMP_JLE_K:
- if (DST <= IMM) {
- insn += insn->off;
- CONT_JMP;
- }
- CONT;
- JMP_JSGT_X:
- if (((s64) DST) > ((s64) SRC)) {
- insn += insn->off;
- CONT_JMP;
- }
- CONT;
- JMP_JSGT_K:
- if (((s64) DST) > ((s64) IMM)) {
- insn += insn->off;
- CONT_JMP;
- }
- CONT;
- JMP_JSLT_X:
- if (((s64) DST) < ((s64) SRC)) {
- insn += insn->off;
- CONT_JMP;
- }
- CONT;
- JMP_JSLT_K:
- if (((s64) DST) < ((s64) IMM)) {
- insn += insn->off;
- CONT_JMP;
- }
- CONT;
- JMP_JSGE_X:
- if (((s64) DST) >= ((s64) SRC)) {
- insn += insn->off;
- CONT_JMP;
- }
- CONT;
- JMP_JSGE_K:
- if (((s64) DST) >= ((s64) IMM)) {
- insn += insn->off;
- CONT_JMP;
- }
- CONT;
- JMP_JSLE_X:
- if (((s64) DST) <= ((s64) SRC)) {
- insn += insn->off;
- CONT_JMP;
- }
- CONT;
- JMP_JSLE_K:
- if (((s64) DST) <= ((s64) IMM)) {
- insn += insn->off;
- CONT_JMP;
- }
- CONT;
- JMP_JSET_X:
- if (DST & SRC) {
- insn += insn->off;
- CONT_JMP;
- }
- CONT;
- JMP_JSET_K:
- if (DST & IMM) {
- insn += insn->off;
- CONT_JMP;
- }
- CONT;
- JMP_EXIT:
- return BPF_R0;
- /* STX and ST and LDX*/
- #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;
- LDST(B, u8)
- LDST(H, u16)
- LDST(W, u32)
- LDST(DW, u64)
- #undef LDST
- STX_XADD_W: /* lock xadd *(u32 *)(dst_reg + off16) += src_reg */
- atomic_add((u32) SRC, (atomic_t *)(unsigned long)
- (DST + insn->off));
- CONT;
- STX_XADD_DW: /* lock xadd *(u64 *)(dst_reg + off16) += src_reg */
- atomic64_add((u64) SRC, (atomic64_t *)(unsigned long)
- (DST + insn->off));
- 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\n", insn->code);
- BUG_ON(1);
- return 0;
- }
- STACK_FRAME_NON_STANDARD(___bpf_prog_run); /* jump table */
- #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, stack); \
- }
- #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, stack); \
- }
- #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_array_compatible(struct bpf_array *array,
- const struct bpf_prog *fp)
- {
- if (fp->kprobe_override)
- return false;
- if (!array->owner_prog_type) {
- /* There's no owner yet where we could check for
- * compatibility.
- */
- array->owner_prog_type = fp->type;
- array->owner_jited = fp->jited;
- return true;
- }
- return array->owner_prog_type == fp->type &&
- array->owner_jited == fp->jited;
- }
- static int bpf_check_tail_call(const struct bpf_prog *fp)
- {
- struct bpf_prog_aux *aux = fp->aux;
- int i;
- for (i = 0; i < aux->used_map_cnt; i++) {
- struct bpf_map *map = aux->used_maps[i];
- struct bpf_array *array;
- if (map->map_type != BPF_MAP_TYPE_PROG_ARRAY)
- continue;
- array = container_of(map, struct bpf_array, map);
- if (!bpf_prog_array_compatible(array, fp))
- return -EINVAL;
- }
- return 0;
- }
- 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 internal 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() macro.
- */
- 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.
- */
- if (fp->bpf_func)
- goto finalize;
- 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)) {
- fp = bpf_int_jit_compile(fp);
- #ifdef CONFIG_BPF_JIT_ALWAYS_ON
- if (!fp->jited) {
- *err = -ENOTSUPP;
- return fp;
- }
- #endif
- } 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,
- },
- };
- /* to avoid allocating empty bpf_prog_array for cgroups that
- * don't have bpf program attached use one global 'empty_prog_array'
- * It will not be modified the caller of bpf_prog_array_alloc()
- * (since caller requested prog_cnt == 0)
- * that pointer should be 'freed' by bpf_prog_array_free()
- */
- static struct {
- struct bpf_prog_array hdr;
- struct bpf_prog *null_prog;
- } empty_prog_array = {
- .null_prog = NULL,
- };
- 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 &empty_prog_array.hdr;
- }
- void bpf_prog_array_free(struct bpf_prog_array __rcu *progs)
- {
- if (!progs ||
- progs == (struct bpf_prog_array __rcu *)&empty_prog_array.hdr)
- return;
- kfree_rcu(progs, rcu);
- }
- int bpf_prog_array_length(struct bpf_prog_array __rcu *array)
- {
- struct bpf_prog_array_item *item;
- u32 cnt = 0;
- rcu_read_lock();
- item = rcu_dereference(array)->items;
- for (; item->prog; item++)
- if (item->prog != &dummy_bpf_prog.prog)
- cnt++;
- rcu_read_unlock();
- return cnt;
- }
- static bool bpf_prog_array_copy_core(struct bpf_prog_array __rcu *array,
- u32 *prog_ids,
- u32 request_cnt)
- {
- struct bpf_prog_array_item *item;
- int i = 0;
- item = rcu_dereference_check(array, 1)->items;
- for (; 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 __rcu *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, but
- * bpf_prog_array_length() releases rcu lock and
- * prog array could have been swapped with empty or larger array,
- * so always copy 'cnt' prog_ids to the user.
- * In a rare race the user will see zero prog_ids
- */
- ids = kcalloc(cnt, sizeof(u32), GFP_USER | __GFP_NOWARN);
- if (!ids)
- return -ENOMEM;
- rcu_read_lock();
- nospc = bpf_prog_array_copy_core(array, ids, cnt);
- rcu_read_unlock();
- 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 __rcu *array,
- struct bpf_prog *old_prog)
- {
- struct bpf_prog_array_item *item = array->items;
- for (; item->prog; item++)
- if (item->prog == old_prog) {
- WRITE_ONCE(item->prog, &dummy_bpf_prog.prog);
- break;
- }
- }
- int bpf_prog_array_copy(struct bpf_prog_array __rcu *old_array,
- struct bpf_prog *exclude_prog,
- struct bpf_prog *include_prog,
- struct bpf_prog_array **new_array)
- {
- int new_prog_cnt, carry_prog_cnt = 0;
- struct bpf_prog_array_item *existing;
- struct bpf_prog_array *array;
- bool found_exclude = false;
- int new_prog_idx = 0;
- /* 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;
- /* 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) {
- array->items[new_prog_idx++].prog =
- existing->prog;
- }
- }
- if (include_prog)
- array->items[new_prog_idx++].prog = include_prog;
- array->items[new_prog_idx].prog = NULL;
- *new_array = array;
- return 0;
- }
- int bpf_prog_array_copy_info(struct bpf_prog_array __rcu *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;
- }
- 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);
- 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
- for (i = 0; i < aux->func_cnt; i++)
- 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);
- }
- }
- /* Free internal BPF program */
- void bpf_prog_free(struct bpf_prog *fp)
- {
- struct bpf_prog_aux *aux = fp->aux;
- 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;
- }
- /* 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_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_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_sock_map_update_proto __weak;
- const struct bpf_func_proto bpf_sock_hash_update_proto __weak;
- const struct bpf_func_proto bpf_get_current_cgroup_id_proto __weak;
- const struct bpf_func_proto bpf_get_local_storage_proto __weak;
- const struct bpf_func_proto * __weak bpf_get_trace_printk_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;
- }
- /* 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;
- }
- /* All definitions of tracepoints related to BPF. */
- #define CREATE_TRACE_POINTS
- #include <linux/bpf_trace.h>
- EXPORT_TRACEPOINT_SYMBOL_GPL(xdp_exception);
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