insn->src_reg == BPF_PSEUDO_CALL;
}
+static bool bpf_pseudo_func(const struct bpf_insn *insn)
+{
+ return insn->code == (BPF_LD | BPF_IMM | BPF_DW) &&
+ insn->src_reg == BPF_PSEUDO_FUNC;
+}
+
struct bpf_call_arg_meta {
struct bpf_map *map_ptr;
bool raw_mode;
u32 btf_id;
struct btf *ret_btf;
u32 ret_btf_id;
+ u32 subprogno;
};
struct btf *btf_vmlinux;
env->prev_linfo = linfo;
}
+static void verbose_invalid_scalar(struct bpf_verifier_env *env,
+ struct bpf_reg_state *reg,
+ struct tnum *range, const char *ctx,
+ const char *reg_name)
+{
+ char tn_buf[48];
+
+ verbose(env, "At %s the register %s ", ctx, reg_name);
+ if (!tnum_is_unknown(reg->var_off)) {
+ tnum_strn(tn_buf, sizeof(tn_buf), reg->var_off);
+ verbose(env, "has value %s", tn_buf);
+ } else {
+ verbose(env, "has unknown scalar value");
+ }
+ tnum_strn(tn_buf, sizeof(tn_buf), *range);
+ verbose(env, " should have been in %s\n", tn_buf);
+}
+
static bool type_is_pkt_pointer(enum bpf_reg_type type)
{
return type == PTR_TO_PACKET ||
return type == PTR_TO_SOCKET ||
type == PTR_TO_TCP_SOCK ||
type == PTR_TO_MAP_VALUE ||
+ type == PTR_TO_MAP_KEY ||
type == PTR_TO_SOCK_COMMON;
}
type == ARG_PTR_TO_MEM_OR_NULL ||
type == ARG_PTR_TO_CTX_OR_NULL ||
type == ARG_PTR_TO_SOCKET_OR_NULL ||
- type == ARG_PTR_TO_ALLOC_MEM_OR_NULL;
+ type == ARG_PTR_TO_ALLOC_MEM_OR_NULL ||
+ type == ARG_PTR_TO_STACK_OR_NULL;
}
/* Determine whether the function releases some resources allocated by another
[PTR_TO_RDONLY_BUF_OR_NULL] = "rdonly_buf_or_null",
[PTR_TO_RDWR_BUF] = "rdwr_buf",
[PTR_TO_RDWR_BUF_OR_NULL] = "rdwr_buf_or_null",
+ [PTR_TO_FUNC] = "func",
+ [PTR_TO_MAP_KEY] = "map_key",
};
static char slot_type_char[] = {
if (type_is_pkt_pointer(t))
verbose(env, ",r=%d", reg->range);
else if (t == CONST_PTR_TO_MAP ||
+ t == PTR_TO_MAP_KEY ||
t == PTR_TO_MAP_VALUE ||
t == PTR_TO_MAP_VALUE_OR_NULL)
verbose(env, ",ks=%d,vs=%d",
}
ret = find_subprog(env, off);
if (ret >= 0)
- return 0;
+ return ret;
if (env->subprog_cnt >= BPF_MAX_SUBPROGS) {
verbose(env, "too many subprograms\n");
return -E2BIG;
env->subprog_info[env->subprog_cnt++].start = off;
sort(env->subprog_info, env->subprog_cnt,
sizeof(env->subprog_info[0]), cmp_subprogs, NULL);
- return 0;
+ return env->subprog_cnt - 1;
}
static int check_subprogs(struct bpf_verifier_env *env)
/* determine subprog starts. The end is one before the next starts */
for (i = 0; i < insn_cnt; i++) {
+ if (bpf_pseudo_func(insn + i)) {
+ if (!env->bpf_capable) {
+ verbose(env,
+ "function pointers are allowed for CAP_BPF and CAP_SYS_ADMIN\n");
+ return -EPERM;
+ }
+ ret = add_subprog(env, i + insn[i].imm + 1);
+ if (ret < 0)
+ return ret;
+ /* remember subprog */
+ insn[i + 1].imm = ret;
+ continue;
+ }
if (!bpf_pseudo_call(insn + i))
continue;
if (!env->bpf_capable) {
case PTR_TO_PERCPU_BTF_ID:
case PTR_TO_MEM:
case PTR_TO_MEM_OR_NULL:
+ case PTR_TO_FUNC:
+ case PTR_TO_MAP_KEY:
return true;
default:
return false;
reg = &cur_regs(env)[regno];
switch (reg->type) {
+ case PTR_TO_MAP_KEY:
+ verbose(env, "invalid access to map key, key_size=%d off=%d size=%d\n",
+ mem_size, off, size);
+ break;
case PTR_TO_MAP_VALUE:
verbose(env, "invalid access to map value, value_size=%d off=%d size=%d\n",
mem_size, off, size);
case PTR_TO_FLOW_KEYS:
pointer_desc = "flow keys ";
break;
+ case PTR_TO_MAP_KEY:
+ pointer_desc = "key ";
+ break;
case PTR_TO_MAP_VALUE:
pointer_desc = "value ";
break;
continue_func:
subprog_end = subprog[idx + 1].start;
for (; i < subprog_end; i++) {
- if (!bpf_pseudo_call(insn + i))
+ if (!bpf_pseudo_call(insn + i) && !bpf_pseudo_func(insn + i))
continue;
/* remember insn and function to return to */
ret_insn[frame] = i + 1;
/* for access checks, reg->off is just part of off */
off += reg->off;
- if (reg->type == PTR_TO_MAP_VALUE) {
+ if (reg->type == PTR_TO_MAP_KEY) {
+ if (t == BPF_WRITE) {
+ verbose(env, "write to change key R%d not allowed\n", regno);
+ return -EACCES;
+ }
+
+ err = check_mem_region_access(env, regno, off, size,
+ reg->map_ptr->key_size, false);
+ if (err)
+ return err;
+ if (value_regno >= 0)
+ mark_reg_unknown(env, regs, value_regno);
+ } else if (reg->type == PTR_TO_MAP_VALUE) {
if (t == BPF_WRITE && value_regno >= 0 &&
is_pointer_value(env, value_regno)) {
verbose(env, "R%d leaks addr into map\n", value_regno);
case PTR_TO_PACKET_META:
return check_packet_access(env, regno, reg->off, access_size,
zero_size_allowed);
+ case PTR_TO_MAP_KEY:
+ return check_mem_region_access(env, regno, reg->off, access_size,
+ reg->map_ptr->key_size, false);
case PTR_TO_MAP_VALUE:
if (check_map_access_type(env, regno, reg->off, access_size,
meta && meta->raw_mode ? BPF_WRITE :
PTR_TO_STACK,
PTR_TO_PACKET,
PTR_TO_PACKET_META,
+ PTR_TO_MAP_KEY,
PTR_TO_MAP_VALUE,
},
};
PTR_TO_STACK,
PTR_TO_PACKET,
PTR_TO_PACKET_META,
+ PTR_TO_MAP_KEY,
PTR_TO_MAP_VALUE,
PTR_TO_MEM,
PTR_TO_RDONLY_BUF,
PTR_TO_STACK,
PTR_TO_PACKET,
PTR_TO_PACKET_META,
+ PTR_TO_MAP_KEY,
PTR_TO_MAP_VALUE,
},
};
static const struct bpf_reg_types btf_ptr_types = { .types = { PTR_TO_BTF_ID } };
static const struct bpf_reg_types spin_lock_types = { .types = { PTR_TO_MAP_VALUE } };
static const struct bpf_reg_types percpu_btf_ptr_types = { .types = { PTR_TO_PERCPU_BTF_ID } };
+static const struct bpf_reg_types func_ptr_types = { .types = { PTR_TO_FUNC } };
+static const struct bpf_reg_types stack_ptr_types = { .types = { PTR_TO_STACK } };
static const struct bpf_reg_types *compatible_reg_types[__BPF_ARG_TYPE_MAX] = {
[ARG_PTR_TO_MAP_KEY] = &map_key_value_types,
[ARG_PTR_TO_INT] = &int_ptr_types,
[ARG_PTR_TO_LONG] = &int_ptr_types,
[ARG_PTR_TO_PERCPU_BTF_ID] = &percpu_btf_ptr_types,
+ [ARG_PTR_TO_FUNC] = &func_ptr_types,
+ [ARG_PTR_TO_STACK_OR_NULL] = &stack_ptr_types,
};
static int check_reg_type(struct bpf_verifier_env *env, u32 regno,
verbose(env, "verifier internal error\n");
return -EFAULT;
}
+ } else if (arg_type == ARG_PTR_TO_FUNC) {
+ meta->subprogno = reg->subprogno;
} else if (arg_type_is_mem_ptr(arg_type)) {
/* The access to this pointer is only checked when we hit the
* next is_mem_size argument below.
}
}
-static int check_func_call(struct bpf_verifier_env *env, struct bpf_insn *insn,
- int *insn_idx)
+typedef int (*set_callee_state_fn)(struct bpf_verifier_env *env,
+ struct bpf_func_state *caller,
+ struct bpf_func_state *callee,
+ int insn_idx);
+
+static int __check_func_call(struct bpf_verifier_env *env, struct bpf_insn *insn,
+ int *insn_idx, int subprog,
+ set_callee_state_fn set_callee_state_cb)
{
struct bpf_verifier_state *state = env->cur_state;
struct bpf_func_info_aux *func_info_aux;
struct bpf_func_state *caller, *callee;
- int i, err, subprog, target_insn;
+ int err;
bool is_global = false;
if (state->curframe + 1 >= MAX_CALL_FRAMES) {
return -E2BIG;
}
- target_insn = *insn_idx + insn->imm;
- subprog = find_subprog(env, target_insn + 1);
- if (subprog < 0) {
- verbose(env, "verifier bug. No program starts at insn %d\n",
- target_insn + 1);
- return -EFAULT;
- }
-
caller = state->frame[state->curframe];
if (state->frame[state->curframe + 1]) {
verbose(env, "verifier bug. Frame %d already allocated\n",
if (err)
return err;
- /* copy r1 - r5 args that callee can access. The copy includes parent
- * pointers, which connects us up to the liveness chain
- */
- for (i = BPF_REG_1; i <= BPF_REG_5; i++)
- callee->regs[i] = caller->regs[i];
+ err = set_callee_state_cb(env, caller, callee, *insn_idx);
+ if (err)
+ return err;
clear_caller_saved_regs(env, caller->regs);
state->curframe++;
/* and go analyze first insn of the callee */
- *insn_idx = target_insn;
+ *insn_idx = env->subprog_info[subprog].start - 1;
if (env->log.level & BPF_LOG_LEVEL) {
verbose(env, "caller:\n");
return 0;
}
+int map_set_for_each_callback_args(struct bpf_verifier_env *env,
+ struct bpf_func_state *caller,
+ struct bpf_func_state *callee)
+{
+ /* bpf_for_each_map_elem(struct bpf_map *map, void *callback_fn,
+ * void *callback_ctx, u64 flags);
+ * callback_fn(struct bpf_map *map, void *key, void *value,
+ * void *callback_ctx);
+ */
+ callee->regs[BPF_REG_1] = caller->regs[BPF_REG_1];
+
+ callee->regs[BPF_REG_2].type = PTR_TO_MAP_KEY;
+ __mark_reg_known_zero(&callee->regs[BPF_REG_2]);
+ callee->regs[BPF_REG_2].map_ptr = caller->regs[BPF_REG_1].map_ptr;
+
+ callee->regs[BPF_REG_3].type = PTR_TO_MAP_VALUE;
+ __mark_reg_known_zero(&callee->regs[BPF_REG_3]);
+ callee->regs[BPF_REG_3].map_ptr = caller->regs[BPF_REG_1].map_ptr;
+
+ /* pointer to stack or null */
+ callee->regs[BPF_REG_4] = caller->regs[BPF_REG_3];
+
+ /* unused */
+ __mark_reg_not_init(env, &callee->regs[BPF_REG_5]);
+ return 0;
+}
+
+static int set_callee_state(struct bpf_verifier_env *env,
+ struct bpf_func_state *caller,
+ struct bpf_func_state *callee, int insn_idx)
+{
+ int i;
+
+ /* copy r1 - r5 args that callee can access. The copy includes parent
+ * pointers, which connects us up to the liveness chain
+ */
+ for (i = BPF_REG_1; i <= BPF_REG_5; i++)
+ callee->regs[i] = caller->regs[i];
+ return 0;
+}
+
+static int check_func_call(struct bpf_verifier_env *env, struct bpf_insn *insn,
+ int *insn_idx)
+{
+ int subprog, target_insn;
+
+ target_insn = *insn_idx + insn->imm + 1;
+ subprog = find_subprog(env, target_insn);
+ if (subprog < 0) {
+ verbose(env, "verifier bug. No program starts at insn %d\n",
+ target_insn);
+ return -EFAULT;
+ }
+
+ return __check_func_call(env, insn, insn_idx, subprog, set_callee_state);
+}
+
+static int set_map_elem_callback_state(struct bpf_verifier_env *env,
+ struct bpf_func_state *caller,
+ struct bpf_func_state *callee,
+ int insn_idx)
+{
+ struct bpf_insn_aux_data *insn_aux = &env->insn_aux_data[insn_idx];
+ struct bpf_map *map;
+ int err;
+
+ if (bpf_map_ptr_poisoned(insn_aux)) {
+ verbose(env, "tail_call abusing map_ptr\n");
+ return -EINVAL;
+ }
+
+ map = BPF_MAP_PTR(insn_aux->map_ptr_state);
+ if (!map->ops->map_set_for_each_callback_args ||
+ !map->ops->map_for_each_callback) {
+ verbose(env, "callback function not allowed for map\n");
+ return -ENOTSUPP;
+ }
+
+ err = map->ops->map_set_for_each_callback_args(env, caller, callee);
+ if (err)
+ return err;
+
+ callee->in_callback_fn = true;
+ return 0;
+}
+
static int prepare_func_exit(struct bpf_verifier_env *env, int *insn_idx)
{
struct bpf_verifier_state *state = env->cur_state;
state->curframe--;
caller = state->frame[state->curframe];
- /* return to the caller whatever r0 had in the callee */
- caller->regs[BPF_REG_0] = *r0;
+ if (callee->in_callback_fn) {
+ /* enforce R0 return value range [0, 1]. */
+ struct tnum range = tnum_range(0, 1);
+
+ if (r0->type != SCALAR_VALUE) {
+ verbose(env, "R0 not a scalar value\n");
+ return -EACCES;
+ }
+ if (!tnum_in(range, r0->var_off)) {
+ verbose_invalid_scalar(env, r0, &range, "callback return", "R0");
+ return -EINVAL;
+ }
+ } else {
+ /* return to the caller whatever r0 had in the callee */
+ caller->regs[BPF_REG_0] = *r0;
+ }
/* Transfer references to the caller */
err = transfer_reference_state(caller, callee);
func_id != BPF_FUNC_map_delete_elem &&
func_id != BPF_FUNC_map_push_elem &&
func_id != BPF_FUNC_map_pop_elem &&
- func_id != BPF_FUNC_map_peek_elem)
+ func_id != BPF_FUNC_map_peek_elem &&
+ func_id != BPF_FUNC_for_each_map_elem &&
+ func_id != BPF_FUNC_redirect_map)
return 0;
if (map == NULL) {
return state->acquired_refs ? -EINVAL : 0;
}
-static int check_helper_call(struct bpf_verifier_env *env, int func_id, int insn_idx)
+static int check_helper_call(struct bpf_verifier_env *env, struct bpf_insn *insn,
+ int *insn_idx_p)
{
const struct bpf_func_proto *fn = NULL;
struct bpf_reg_state *regs;
struct bpf_call_arg_meta meta;
+ int insn_idx = *insn_idx_p;
bool changes_data;
- int i, err;
+ int i, err, func_id;
/* find function prototype */
+ func_id = insn->imm;
if (func_id < 0 || func_id >= __BPF_FUNC_MAX_ID) {
verbose(env, "invalid func %s#%d\n", func_id_name(func_id),
func_id);
meta.func_id = func_id;
/* check args */
- for (i = 0; i < 5; i++) {
+ for (i = 0; i < MAX_BPF_FUNC_REG_ARGS; i++) {
err = check_func_arg(env, i, &meta, fn);
if (err)
return err;
return -EINVAL;
}
+ if (func_id == BPF_FUNC_for_each_map_elem) {
+ err = __check_func_call(env, insn, insn_idx_p, meta.subprogno,
+ set_map_elem_callback_state);
+ if (err < 0)
+ return -EINVAL;
+ }
+
/* reset caller saved regs */
for (i = 0; i < CALLER_SAVED_REGS; i++) {
mark_reg_not_init(env, regs, caller_saved[i]);
else
*ptr_limit = -off;
return 0;
+ case PTR_TO_MAP_KEY:
+ /* Currently, this code is not exercised as the only use
+ * is bpf_for_each_map_elem() helper which requires
+ * bpf_capble. The code has been tested manually for
+ * future use.
+ */
+ if (mask_to_left) {
+ *ptr_limit = ptr_reg->umax_value + ptr_reg->off;
+ } else {
+ off = ptr_reg->smin_value + ptr_reg->off;
+ *ptr_limit = ptr_reg->map_ptr->key_size - off;
+ }
+ return 0;
case PTR_TO_MAP_VALUE:
if (mask_to_left) {
*ptr_limit = ptr_reg->umax_value + ptr_reg->off;
aux->alu_limit != alu_limit))
return -EACCES;
- /* Corresponding fixup done in fixup_bpf_calls(). */
+ /* Corresponding fixup done in do_misc_fixups(). */
aux->alu_state = alu_state;
aux->alu_limit = alu_limit;
return 0;
verbose(env, "R%d pointer arithmetic on %s prohibited\n",
dst, reg_type_str[ptr_reg->type]);
return -EACCES;
+ case PTR_TO_MAP_KEY:
case PTR_TO_MAP_VALUE:
if (!env->allow_ptr_leaks && !known && (smin_val < 0) != (smax_val < 0)) {
verbose(env, "R%d has unknown scalar with mixed signed bounds, pointer arithmetic with it prohibited for !root\n",
return 0;
}
+ if (insn->src_reg == BPF_PSEUDO_FUNC) {
+ struct bpf_prog_aux *aux = env->prog->aux;
+ u32 subprogno = insn[1].imm;
+
+ if (!aux->func_info) {
+ verbose(env, "missing btf func_info\n");
+ return -EINVAL;
+ }
+ if (aux->func_info_aux[subprogno].linkage != BTF_FUNC_STATIC) {
+ verbose(env, "callback function not static\n");
+ return -EINVAL;
+ }
+
+ dst_reg->type = PTR_TO_FUNC;
+ dst_reg->subprogno = subprogno;
+ return 0;
+ }
+
map = env->used_maps[aux->map_index];
mark_reg_known_zero(env, regs, insn->dst_reg);
dst_reg->map_ptr = map;
}
if (!tnum_in(range, reg->var_off)) {
- char tn_buf[48];
-
- verbose(env, "At program exit the register R0 ");
- if (!tnum_is_unknown(reg->var_off)) {
- tnum_strn(tn_buf, sizeof(tn_buf), reg->var_off);
- verbose(env, "has value %s", tn_buf);
- } else {
- verbose(env, "has unknown scalar value");
- }
- tnum_strn(tn_buf, sizeof(tn_buf), range);
- verbose(env, " should have been in %s\n", tn_buf);
+ verbose_invalid_scalar(env, reg, &range, "program exit", "R0");
return -EINVAL;
}
return DONE_EXPLORING;
}
+static int visit_func_call_insn(int t, int insn_cnt,
+ struct bpf_insn *insns,
+ struct bpf_verifier_env *env,
+ bool visit_callee)
+{
+ int ret;
+
+ ret = push_insn(t, t + 1, FALLTHROUGH, env, false);
+ if (ret)
+ return ret;
+
+ if (t + 1 < insn_cnt)
+ init_explored_state(env, t + 1);
+ if (visit_callee) {
+ init_explored_state(env, t);
+ ret = push_insn(t, t + insns[t].imm + 1, BRANCH,
+ env, false);
+ }
+ return ret;
+}
+
/* Visits the instruction at index t and returns one of the following:
* < 0 - an error occurred
* DONE_EXPLORING - the instruction was fully explored
struct bpf_insn *insns = env->prog->insnsi;
int ret;
+ if (bpf_pseudo_func(insns + t))
+ return visit_func_call_insn(t, insn_cnt, insns, env, true);
+
/* All non-branch instructions have a single fall-through edge. */
if (BPF_CLASS(insns[t].code) != BPF_JMP &&
BPF_CLASS(insns[t].code) != BPF_JMP32)
return DONE_EXPLORING;
case BPF_CALL:
- ret = push_insn(t, t + 1, FALLTHROUGH, env, false);
- if (ret)
- return ret;
-
- if (t + 1 < insn_cnt)
- init_explored_state(env, t + 1);
- if (insns[t].src_reg == BPF_PSEUDO_CALL) {
- init_explored_state(env, t);
- ret = push_insn(t, t + insns[t].imm + 1, BRANCH,
- env, false);
- }
- return ret;
+ return visit_func_call_insn(t, insn_cnt, insns, env,
+ insns[t].src_reg == BPF_PSEUDO_CALL);
case BPF_JA:
if (BPF_SRC(insns[t].code) != BPF_K)
*/
return false;
}
+ case PTR_TO_MAP_KEY:
case PTR_TO_MAP_VALUE:
/* If the new min/max/var_off satisfy the old ones and
* everything else matches, we are OK.
if (insn->src_reg == BPF_PSEUDO_CALL)
err = check_func_call(env, insn, &env->insn_idx);
else
- err = check_helper_call(env, insn->imm, env->insn_idx);
+ err = check_helper_call(env, insn, &env->insn_idx);
if (err)
return err;
-
} else if (opcode == BPF_JA) {
if (BPF_SRC(insn->code) != BPF_K ||
insn->imm != 0 ||
goto next_insn;
}
+ if (insn[0].src_reg == BPF_PSEUDO_FUNC) {
+ aux = &env->insn_aux_data[i];
+ aux->ptr_type = PTR_TO_FUNC;
+ goto next_insn;
+ }
+
/* In final convert_pseudo_ld_imm64() step, this is
* converted into regular 64-bit imm load insn.
*/
int insn_cnt = env->prog->len;
int i;
- for (i = 0; i < insn_cnt; i++, insn++)
- if (insn->code == (BPF_LD | BPF_IMM | BPF_DW))
- insn->src_reg = 0;
+ for (i = 0; i < insn_cnt; i++, insn++) {
+ if (insn->code != (BPF_LD | BPF_IMM | BPF_DW))
+ continue;
+ if (insn->src_reg == BPF_PSEUDO_FUNC)
+ continue;
+ insn->src_reg = 0;
+ }
}
/* single env->prog->insni[off] instruction was replaced with the range
return 0;
for (i = 0, insn = prog->insnsi; i < prog->len; i++, insn++) {
+ if (bpf_pseudo_func(insn)) {
+ env->insn_aux_data[i].call_imm = insn->imm;
+ /* subprog is encoded in insn[1].imm */
+ continue;
+ }
+
if (!bpf_pseudo_call(insn))
continue;
/* Upon error here we cannot fall back to interpreter but
for (i = 0; i < env->subprog_cnt; i++) {
insn = func[i]->insnsi;
for (j = 0; j < func[i]->len; j++, insn++) {
+ if (bpf_pseudo_func(insn)) {
+ subprog = insn[1].imm;
+ insn[0].imm = (u32)(long)func[subprog]->bpf_func;
+ insn[1].imm = ((u64)(long)func[subprog]->bpf_func) >> 32;
+ continue;
+ }
if (!bpf_pseudo_call(insn))
continue;
subprog = insn->off;
* later look the same as if they were interpreted only.
*/
for (i = 0, insn = prog->insnsi; i < prog->len; i++, insn++) {
+ if (bpf_pseudo_func(insn)) {
+ insn[0].imm = env->insn_aux_data[i].call_imm;
+ insn[1].imm = find_subprog(env, i + insn[0].imm + 1);
+ continue;
+ }
if (!bpf_pseudo_call(insn))
continue;
insn->off = env->insn_aux_data[i].call_imm;
return -EINVAL;
}
for (i = 0; i < prog->len; i++, insn++) {
+ if (bpf_pseudo_func(insn)) {
+ /* When JIT fails the progs with callback calls
+ * have to be rejected, since interpreter doesn't support them yet.
+ */
+ verbose(env, "callbacks are not allowed in non-JITed programs\n");
+ return -EINVAL;
+ }
+
if (!bpf_pseudo_call(insn))
continue;
depth = get_callee_stack_depth(env, insn, i);
return err;
}
-/* fixup insn->imm field of bpf_call instructions
- * and inline eligible helpers as explicit sequence of BPF instructions
- *
- * this function is called after eBPF program passed verification
+/* Do various post-verification rewrites in a single program pass.
+ * These rewrites simplify JIT and interpreter implementations.
*/
-static int fixup_bpf_calls(struct bpf_verifier_env *env)
+static int do_misc_fixups(struct bpf_verifier_env *env)
{
struct bpf_prog *prog = env->prog;
bool expect_blinding = bpf_jit_blinding_enabled(prog);
int i, ret, cnt, delta = 0;
for (i = 0; i < insn_cnt; i++, insn++) {
+ /* Make divide-by-zero exceptions impossible. */
if (insn->code == (BPF_ALU64 | BPF_MOD | BPF_X) ||
insn->code == (BPF_ALU64 | BPF_DIV | BPF_X) ||
insn->code == (BPF_ALU | BPF_MOD | BPF_X) ||
continue;
}
+ /* Implement LD_ABS and LD_IND with a rewrite, if supported by the program type. */
if (BPF_CLASS(insn->code) == BPF_LD &&
(BPF_MODE(insn->code) == BPF_ABS ||
BPF_MODE(insn->code) == BPF_IND)) {
continue;
}
+ /* Rewrite pointer arithmetic to mitigate speculation attacks. */
if (insn->code == (BPF_ALU64 | BPF_ADD | BPF_X) ||
insn->code == (BPF_ALU64 | BPF_SUB | BPF_X)) {
const u8 code_add = BPF_ALU64 | BPF_ADD | BPF_X;
insn->imm == BPF_FUNC_map_delete_elem ||
insn->imm == BPF_FUNC_map_push_elem ||
insn->imm == BPF_FUNC_map_pop_elem ||
- insn->imm == BPF_FUNC_map_peek_elem)) {
+ insn->imm == BPF_FUNC_map_peek_elem ||
+ insn->imm == BPF_FUNC_redirect_map)) {
aux = &env->insn_aux_data[i + delta];
if (bpf_map_ptr_poisoned(aux))
goto patch_call_imm;
(int (*)(struct bpf_map *map, void *value))NULL));
BUILD_BUG_ON(!__same_type(ops->map_peek_elem,
(int (*)(struct bpf_map *map, void *value))NULL));
+ BUILD_BUG_ON(!__same_type(ops->map_redirect,
+ (int (*)(struct bpf_map *map, u32 ifindex, u64 flags))NULL));
+
patch_map_ops_generic:
switch (insn->imm) {
case BPF_FUNC_map_lookup_elem:
insn->imm = BPF_CAST_CALL(ops->map_peek_elem) -
__bpf_call_base;
continue;
+ case BPF_FUNC_redirect_map:
+ insn->imm = BPF_CAST_CALL(ops->map_redirect) -
+ __bpf_call_base;
+ continue;
}
goto patch_call_imm;
}
+ /* Implement bpf_jiffies64 inline. */
if (prog->jit_requested && BITS_PER_LONG == 64 &&
insn->imm == BPF_FUNC_jiffies64) {
struct bpf_insn ld_jiffies_addr[2] = {
ret = convert_ctx_accesses(env);
if (ret == 0)
- ret = fixup_bpf_calls(env);
+ ret = do_misc_fixups(env);
/* do 32-bit optimization after insn patching has done so those patched
* insns could be handled correctly.
projects / platform / kernel / linux-rpi.git / blobdiff