#include <linux/types.h>
#include <linux/slab.h>
#include <linux/bpf.h>
+#include <linux/bpf_verifier.h>
#include <linux/filter.h>
#include <net/netlink.h>
#include <linux/file.h>
* are set to NOT_INIT to indicate that they are no longer readable.
*/
-struct reg_state {
- enum bpf_reg_type type;
- union {
- /* valid when type == CONST_IMM | PTR_TO_STACK | UNKNOWN_VALUE */
- s64 imm;
-
- /* valid when type == PTR_TO_PACKET* */
- struct {
- u32 id;
- u16 off;
- u16 range;
- };
-
- /* valid when type == CONST_PTR_TO_MAP | PTR_TO_MAP_VALUE |
- * PTR_TO_MAP_VALUE_OR_NULL
- */
- struct bpf_map *map_ptr;
- };
-};
-
-enum bpf_stack_slot_type {
- STACK_INVALID, /* nothing was stored in this stack slot */
- STACK_SPILL, /* register spilled into stack */
- STACK_MISC /* BPF program wrote some data into this slot */
-};
-
-#define BPF_REG_SIZE 8 /* size of eBPF register in bytes */
-
-/* state of the program:
- * type of all registers and stack info
- */
-struct verifier_state {
- struct reg_state regs[MAX_BPF_REG];
- u8 stack_slot_type[MAX_BPF_STACK];
- struct reg_state spilled_regs[MAX_BPF_STACK / BPF_REG_SIZE];
-};
-
-/* linked list of verifier states used to prune search */
-struct verifier_state_list {
- struct verifier_state state;
- struct verifier_state_list *next;
-};
-
/* verifier_state + insn_idx are pushed to stack when branch is encountered */
-struct verifier_stack_elem {
+struct bpf_verifier_stack_elem {
/* verifer state is 'st'
* before processing instruction 'insn_idx'
* and after processing instruction 'prev_insn_idx'
*/
- struct verifier_state st;
+ struct bpf_verifier_state st;
int insn_idx;
int prev_insn_idx;
- struct verifier_stack_elem *next;
-};
-
-struct bpf_insn_aux_data {
- enum bpf_reg_type ptr_type; /* pointer type for load/store insns */
-};
-
-#define MAX_USED_MAPS 64 /* max number of maps accessed by one eBPF program */
-
-/* single container for all structs
- * one verifier_env per bpf_check() call
- */
-struct verifier_env {
- struct bpf_prog *prog; /* eBPF program being verified */
- struct verifier_stack_elem *head; /* stack of verifier states to be processed */
- int stack_size; /* number of states to be processed */
- struct verifier_state cur_state; /* current verifier state */
- struct verifier_state_list **explored_states; /* search pruning optimization */
- struct bpf_map *used_maps[MAX_USED_MAPS]; /* array of map's used by eBPF program */
- u32 used_map_cnt; /* number of used maps */
- u32 id_gen; /* used to generate unique reg IDs */
- bool allow_ptr_leaks;
- bool seen_direct_write;
- struct bpf_insn_aux_data *insn_aux_data; /* array of per-insn state */
+ struct bpf_verifier_stack_elem *next;
};
#define BPF_COMPLEXITY_LIMIT_INSNS 65536
[PTR_TO_PACKET_END] = "pkt_end",
};
-static void print_verifier_state(struct verifier_state *state)
+static void print_verifier_state(struct bpf_verifier_state *state)
{
- struct reg_state *reg;
+ struct bpf_reg_state *reg;
enum bpf_reg_type t;
int i;
}
}
-static int pop_stack(struct verifier_env *env, int *prev_insn_idx)
+static int pop_stack(struct bpf_verifier_env *env, int *prev_insn_idx)
{
- struct verifier_stack_elem *elem;
+ struct bpf_verifier_stack_elem *elem;
int insn_idx;
if (env->head == NULL)
return insn_idx;
}
-static struct verifier_state *push_stack(struct verifier_env *env, int insn_idx,
- int prev_insn_idx)
+static struct bpf_verifier_state *push_stack(struct bpf_verifier_env *env,
+ int insn_idx, int prev_insn_idx)
{
- struct verifier_stack_elem *elem;
+ struct bpf_verifier_stack_elem *elem;
- elem = kmalloc(sizeof(struct verifier_stack_elem), GFP_KERNEL);
+ elem = kmalloc(sizeof(struct bpf_verifier_stack_elem), GFP_KERNEL);
if (!elem)
goto err;
BPF_REG_0, BPF_REG_1, BPF_REG_2, BPF_REG_3, BPF_REG_4, BPF_REG_5
};
-static void init_reg_state(struct reg_state *regs)
+static void init_reg_state(struct bpf_reg_state *regs)
{
int i;
regs[BPF_REG_1].type = PTR_TO_CTX;
}
-static void mark_reg_unknown_value(struct reg_state *regs, u32 regno)
+static void mark_reg_unknown_value(struct bpf_reg_state *regs, u32 regno)
{
BUG_ON(regno >= MAX_BPF_REG);
regs[regno].type = UNKNOWN_VALUE;
DST_OP_NO_MARK /* same as above, check only, don't mark */
};
-static int check_reg_arg(struct reg_state *regs, u32 regno,
+static int check_reg_arg(struct bpf_reg_state *regs, u32 regno,
enum reg_arg_type t)
{
if (regno >= MAX_BPF_REG) {
/* check_stack_read/write functions track spill/fill of registers,
* stack boundary and alignment are checked in check_mem_access()
*/
-static int check_stack_write(struct verifier_state *state, int off, int size,
- int value_regno)
+static int check_stack_write(struct bpf_verifier_state *state, int off,
+ int size, int value_regno)
{
int i;
/* caller checked that off % size == 0 and -MAX_BPF_STACK <= off < 0,
} else {
/* regular write of data into stack */
state->spilled_regs[(MAX_BPF_STACK + off) / BPF_REG_SIZE] =
- (struct reg_state) {};
+ (struct bpf_reg_state) {};
for (i = 0; i < size; i++)
state->stack_slot_type[MAX_BPF_STACK + off + i] = STACK_MISC;
return 0;
}
-static int check_stack_read(struct verifier_state *state, int off, int size,
+static int check_stack_read(struct bpf_verifier_state *state, int off, int size,
int value_regno)
{
u8 *slot_type;
}
/* check read/write into map element returned by bpf_map_lookup_elem() */
-static int check_map_access(struct verifier_env *env, u32 regno, int off,
+static int check_map_access(struct bpf_verifier_env *env, u32 regno, int off,
int size)
{
struct bpf_map *map = env->cur_state.regs[regno].map_ptr;
#define MAX_PACKET_OFF 0xffff
-static bool may_access_direct_pkt_data(struct verifier_env *env,
+static bool may_access_direct_pkt_data(struct bpf_verifier_env *env,
const struct bpf_call_arg_meta *meta)
{
switch (env->prog->type) {
}
}
-static int check_packet_access(struct verifier_env *env, u32 regno, int off,
+static int check_packet_access(struct bpf_verifier_env *env, u32 regno, int off,
int size)
{
- struct reg_state *regs = env->cur_state.regs;
- struct reg_state *reg = ®s[regno];
+ struct bpf_reg_state *regs = env->cur_state.regs;
+ struct bpf_reg_state *reg = ®s[regno];
off += reg->off;
if (off < 0 || size <= 0 || off + size > reg->range) {
}
/* check access to 'struct bpf_context' fields */
-static int check_ctx_access(struct verifier_env *env, int off, int size,
+static int check_ctx_access(struct bpf_verifier_env *env, int off, int size,
enum bpf_access_type t, enum bpf_reg_type *reg_type)
{
if (env->prog->aux->ops->is_valid_access &&
return -EACCES;
}
-static bool is_pointer_value(struct verifier_env *env, int regno)
+static bool is_pointer_value(struct bpf_verifier_env *env, int regno)
{
if (env->allow_ptr_leaks)
return false;
}
}
-static int check_ptr_alignment(struct verifier_env *env, struct reg_state *reg,
- int off, int size)
+static int check_ptr_alignment(struct bpf_verifier_env *env,
+ struct bpf_reg_state *reg, int off, int size)
{
if (reg->type != PTR_TO_PACKET) {
if (off % size != 0) {
- verbose("misaligned access off %d size %d\n", off, size);
+ verbose("misaligned access off %d size %d\n",
+ off, size);
return -EACCES;
} else {
return 0;
* if t==write && value_regno==-1, some unknown value is stored into memory
* if t==read && value_regno==-1, don't care what we read from memory
*/
-static int check_mem_access(struct verifier_env *env, u32 regno, int off,
+static int check_mem_access(struct bpf_verifier_env *env, u32 regno, int off,
int bpf_size, enum bpf_access_type t,
int value_regno)
{
- struct verifier_state *state = &env->cur_state;
- struct reg_state *reg = &state->regs[regno];
+ struct bpf_verifier_state *state = &env->cur_state;
+ struct bpf_reg_state *reg = &state->regs[regno];
int size, err = 0;
if (reg->type == PTR_TO_STACK)
return err;
}
-static int check_xadd(struct verifier_env *env, struct bpf_insn *insn)
+static int check_xadd(struct bpf_verifier_env *env, struct bpf_insn *insn)
{
- struct reg_state *regs = env->cur_state.regs;
+ struct bpf_reg_state *regs = env->cur_state.regs;
int err;
if ((BPF_SIZE(insn->code) != BPF_W && BPF_SIZE(insn->code) != BPF_DW) ||
* bytes from that pointer, make sure that it's within stack boundary
* and all elements of stack are initialized
*/
-static int check_stack_boundary(struct verifier_env *env, int regno,
+static int check_stack_boundary(struct bpf_verifier_env *env, int regno,
int access_size, bool zero_size_allowed,
struct bpf_call_arg_meta *meta)
{
- struct verifier_state *state = &env->cur_state;
- struct reg_state *regs = state->regs;
+ struct bpf_verifier_state *state = &env->cur_state;
+ struct bpf_reg_state *regs = state->regs;
int off, i;
if (regs[regno].type != PTR_TO_STACK) {
return 0;
}
-static int check_func_arg(struct verifier_env *env, u32 regno,
+static int check_func_arg(struct bpf_verifier_env *env, u32 regno,
enum bpf_arg_type arg_type,
struct bpf_call_arg_meta *meta)
{
- struct reg_state *regs = env->cur_state.regs, *reg = ®s[regno];
+ struct bpf_reg_state *regs = env->cur_state.regs, *reg = ®s[regno];
enum bpf_reg_type expected_type, type = reg->type;
int err = 0;
return count > 1 ? -EINVAL : 0;
}
-static void clear_all_pkt_pointers(struct verifier_env *env)
+static void clear_all_pkt_pointers(struct bpf_verifier_env *env)
{
- struct verifier_state *state = &env->cur_state;
- struct reg_state *regs = state->regs, *reg;
+ struct bpf_verifier_state *state = &env->cur_state;
+ struct bpf_reg_state *regs = state->regs, *reg;
int i;
for (i = 0; i < MAX_BPF_REG; i++)
}
}
-static int check_call(struct verifier_env *env, int func_id)
+static int check_call(struct bpf_verifier_env *env, int func_id)
{
- struct verifier_state *state = &env->cur_state;
+ struct bpf_verifier_state *state = &env->cur_state;
const struct bpf_func_proto *fn = NULL;
- struct reg_state *regs = state->regs;
- struct reg_state *reg;
+ struct bpf_reg_state *regs = state->regs;
+ struct bpf_reg_state *reg;
struct bpf_call_arg_meta meta;
bool changes_data;
int i, err;
return 0;
}
-static int check_packet_ptr_add(struct verifier_env *env, struct bpf_insn *insn)
+static int check_packet_ptr_add(struct bpf_verifier_env *env,
+ struct bpf_insn *insn)
{
- struct reg_state *regs = env->cur_state.regs;
- struct reg_state *dst_reg = ®s[insn->dst_reg];
- struct reg_state *src_reg = ®s[insn->src_reg];
- struct reg_state tmp_reg;
+ struct bpf_reg_state *regs = env->cur_state.regs;
+ struct bpf_reg_state *dst_reg = ®s[insn->dst_reg];
+ struct bpf_reg_state *src_reg = ®s[insn->src_reg];
+ struct bpf_reg_state tmp_reg;
s32 imm;
if (BPF_SRC(insn->code) == BPF_K) {
return 0;
}
-static int evaluate_reg_alu(struct verifier_env *env, struct bpf_insn *insn)
+static int evaluate_reg_alu(struct bpf_verifier_env *env, struct bpf_insn *insn)
{
- struct reg_state *regs = env->cur_state.regs;
- struct reg_state *dst_reg = ®s[insn->dst_reg];
+ struct bpf_reg_state *regs = env->cur_state.regs;
+ struct bpf_reg_state *dst_reg = ®s[insn->dst_reg];
u8 opcode = BPF_OP(insn->code);
s64 imm_log2;
*/
if (BPF_SRC(insn->code) == BPF_X) {
- struct reg_state *src_reg = ®s[insn->src_reg];
+ struct bpf_reg_state *src_reg = ®s[insn->src_reg];
if (src_reg->type == UNKNOWN_VALUE && src_reg->imm > 0 &&
dst_reg->imm && opcode == BPF_ADD) {
return 0;
}
-static int evaluate_reg_imm_alu(struct verifier_env *env, struct bpf_insn *insn)
+static int evaluate_reg_imm_alu(struct bpf_verifier_env *env,
+ struct bpf_insn *insn)
{
- struct reg_state *regs = env->cur_state.regs;
- struct reg_state *dst_reg = ®s[insn->dst_reg];
- struct reg_state *src_reg = ®s[insn->src_reg];
+ struct bpf_reg_state *regs = env->cur_state.regs;
+ struct bpf_reg_state *dst_reg = ®s[insn->dst_reg];
+ struct bpf_reg_state *src_reg = ®s[insn->src_reg];
u8 opcode = BPF_OP(insn->code);
/* dst_reg->type == CONST_IMM here, simulate execution of 'add' insn.
}
/* check validity of 32-bit and 64-bit arithmetic operations */
-static int check_alu_op(struct verifier_env *env, struct bpf_insn *insn)
+static int check_alu_op(struct bpf_verifier_env *env, struct bpf_insn *insn)
{
- struct reg_state *regs = env->cur_state.regs, *dst_reg;
+ struct bpf_reg_state *regs = env->cur_state.regs, *dst_reg;
u8 opcode = BPF_OP(insn->code);
int err;
return 0;
}
-static void find_good_pkt_pointers(struct verifier_state *state,
- const struct reg_state *dst_reg)
+static void find_good_pkt_pointers(struct bpf_verifier_state *state,
+ struct bpf_reg_state *dst_reg)
{
- struct reg_state *regs = state->regs, *reg;
+ struct bpf_reg_state *regs = state->regs, *reg;
int i;
/* LLVM can generate two kind of checks:
}
}
-static int check_cond_jmp_op(struct verifier_env *env,
+static int check_cond_jmp_op(struct bpf_verifier_env *env,
struct bpf_insn *insn, int *insn_idx)
{
- struct verifier_state *other_branch, *this_branch = &env->cur_state;
- struct reg_state *regs = this_branch->regs, *dst_reg;
+ struct bpf_verifier_state *other_branch, *this_branch = &env->cur_state;
+ struct bpf_reg_state *regs = this_branch->regs, *dst_reg;
u8 opcode = BPF_OP(insn->code);
int err;
if (!other_branch)
return -EFAULT;
- /* detect if R == 0 where R is returned value from bpf_map_lookup_elem() */
+ /* detect if R == 0 where R is returned from bpf_map_lookup_elem() */
if (BPF_SRC(insn->code) == BPF_K &&
insn->imm == 0 && (opcode == BPF_JEQ || opcode == BPF_JNE) &&
dst_reg->type == PTR_TO_MAP_VALUE_OR_NULL) {
}
/* verify BPF_LD_IMM64 instruction */
-static int check_ld_imm(struct verifier_env *env, struct bpf_insn *insn)
+static int check_ld_imm(struct bpf_verifier_env *env, struct bpf_insn *insn)
{
- struct reg_state *regs = env->cur_state.regs;
+ struct bpf_reg_state *regs = env->cur_state.regs;
int err;
if (BPF_SIZE(insn->code) != BPF_DW) {
* Output:
* R0 - 8/16/32-bit skb data converted to cpu endianness
*/
-static int check_ld_abs(struct verifier_env *env, struct bpf_insn *insn)
+static int check_ld_abs(struct bpf_verifier_env *env, struct bpf_insn *insn)
{
- struct reg_state *regs = env->cur_state.regs;
+ struct bpf_reg_state *regs = env->cur_state.regs;
u8 mode = BPF_MODE(insn->code);
- struct reg_state *reg;
+ struct bpf_reg_state *reg;
int i, err;
if (!may_access_skb(env->prog->type)) {
BRANCH = 2,
};
-#define STATE_LIST_MARK ((struct verifier_state_list *) -1L)
+#define STATE_LIST_MARK ((struct bpf_verifier_state_list *) -1L)
static int *insn_stack; /* stack of insns to process */
static int cur_stack; /* current stack index */
* w - next instruction
* e - edge
*/
-static int push_insn(int t, int w, int e, struct verifier_env *env)
+static int push_insn(int t, int w, int e, struct bpf_verifier_env *env)
{
if (e == FALLTHROUGH && insn_state[t] >= (DISCOVERED | FALLTHROUGH))
return 0;
/* non-recursive depth-first-search to detect loops in BPF program
* loop == back-edge in directed graph
*/
-static int check_cfg(struct verifier_env *env)
+static int check_cfg(struct bpf_verifier_env *env)
{
struct bpf_insn *insns = env->prog->insnsi;
int insn_cnt = env->prog->len;
/* the following conditions reduce the number of explored insns
* from ~140k to ~80k for ultra large programs that use a lot of ptr_to_packet
*/
-static bool compare_ptrs_to_packet(struct reg_state *old, struct reg_state *cur)
+static bool compare_ptrs_to_packet(struct bpf_reg_state *old,
+ struct bpf_reg_state *cur)
{
if (old->id != cur->id)
return false;
* whereas register type in current state is meaningful, it means that
* the current state will reach 'bpf_exit' instruction safely
*/
-static bool states_equal(struct verifier_state *old, struct verifier_state *cur)
+static bool states_equal(struct bpf_verifier_state *old,
+ struct bpf_verifier_state *cur)
{
- struct reg_state *rold, *rcur;
+ struct bpf_reg_state *rold, *rcur;
int i;
for (i = 0; i < MAX_BPF_REG; i++) {
* the same, check that stored pointers types
* are the same as well.
* Ex: explored safe path could have stored
- * (struct reg_state) {.type = PTR_TO_STACK, .imm = -8}
+ * (bpf_reg_state) {.type = PTR_TO_STACK, .imm = -8}
* but current path has stored:
- * (struct reg_state) {.type = PTR_TO_STACK, .imm = -16}
+ * (bpf_reg_state) {.type = PTR_TO_STACK, .imm = -16}
* such verifier states are not equivalent.
* return false to continue verification of this path
*/
return true;
}
-static int is_state_visited(struct verifier_env *env, int insn_idx)
+static int is_state_visited(struct bpf_verifier_env *env, int insn_idx)
{
- struct verifier_state_list *new_sl;
- struct verifier_state_list *sl;
+ struct bpf_verifier_state_list *new_sl;
+ struct bpf_verifier_state_list *sl;
sl = env->explored_states[insn_idx];
if (!sl)
* it will be rejected. Since there are no loops, we won't be
* seeing this 'insn_idx' instruction again on the way to bpf_exit
*/
- new_sl = kmalloc(sizeof(struct verifier_state_list), GFP_USER);
+ new_sl = kmalloc(sizeof(struct bpf_verifier_state_list), GFP_USER);
if (!new_sl)
return -ENOMEM;
return 0;
}
-static int do_check(struct verifier_env *env)
+static int do_check(struct bpf_verifier_env *env)
{
- struct verifier_state *state = &env->cur_state;
+ struct bpf_verifier_state *state = &env->cur_state;
struct bpf_insn *insns = env->prog->insnsi;
- struct reg_state *regs = state->regs;
+ struct bpf_reg_state *regs = state->regs;
int insn_cnt = env->prog->len;
int insn_idx, prev_insn_idx = 0;
int insn_processed = 0;
/* look for pseudo eBPF instructions that access map FDs and
* replace them with actual map pointers
*/
-static int replace_map_fd_with_map_ptr(struct verifier_env *env)
+static int replace_map_fd_with_map_ptr(struct bpf_verifier_env *env)
{
struct bpf_insn *insn = env->prog->insnsi;
int insn_cnt = env->prog->len;
}
/* drop refcnt of maps used by the rejected program */
-static void release_maps(struct verifier_env *env)
+static void release_maps(struct bpf_verifier_env *env)
{
int i;
}
/* convert pseudo BPF_LD_IMM64 into generic BPF_LD_IMM64 */
-static void convert_pseudo_ld_imm64(struct verifier_env *env)
+static void convert_pseudo_ld_imm64(struct bpf_verifier_env *env)
{
struct bpf_insn *insn = env->prog->insnsi;
int insn_cnt = env->prog->len;
/* convert load instructions that access fields of 'struct __sk_buff'
* into sequence of instructions that access fields of 'struct sk_buff'
*/
-static int convert_ctx_accesses(struct verifier_env *env)
+static int convert_ctx_accesses(struct bpf_verifier_env *env)
{
const struct bpf_verifier_ops *ops = env->prog->aux->ops;
const int insn_cnt = env->prog->len;
return 0;
}
-static void free_states(struct verifier_env *env)
+static void free_states(struct bpf_verifier_env *env)
{
- struct verifier_state_list *sl, *sln;
+ struct bpf_verifier_state_list *sl, *sln;
int i;
if (!env->explored_states)
int bpf_check(struct bpf_prog **prog, union bpf_attr *attr)
{
char __user *log_ubuf = NULL;
- struct verifier_env *env;
+ struct bpf_verifier_env *env;
int ret = -EINVAL;
if ((*prog)->len <= 0 || (*prog)->len > BPF_MAXINSNS)
return -E2BIG;
- /* 'struct verifier_env' can be global, but since it's not small,
+ /* 'struct bpf_verifier_env' can be global, but since it's not small,
* allocate/free it every time bpf_check() is called
*/
- env = kzalloc(sizeof(struct verifier_env), GFP_KERNEL);
+ env = kzalloc(sizeof(struct bpf_verifier_env), GFP_KERNEL);
if (!env)
return -ENOMEM;
goto skip_full_check;
env->explored_states = kcalloc(env->prog->len,
- sizeof(struct verifier_state_list *),
+ sizeof(struct bpf_verifier_state_list *),
GFP_USER);
ret = -ENOMEM;
if (!env->explored_states)