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Diffstat (limited to 'include/linux/bpf_verifier.h')
| -rw-r--r-- | include/linux/bpf_verifier.h | 665 |
1 files changed, 665 insertions, 0 deletions
diff --git a/include/linux/bpf_verifier.h b/include/linux/bpf_verifier.h new file mode 100644 index 000000000..f080ccf27 --- /dev/null +++ b/include/linux/bpf_verifier.h @@ -0,0 +1,665 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* Copyright (c) 2011-2014 PLUMgrid, http://plumgrid.com + */ +#ifndef _LINUX_BPF_VERIFIER_H +#define _LINUX_BPF_VERIFIER_H 1 + +#include <linux/bpf.h> /* for enum bpf_reg_type */ +#include <linux/btf.h> /* for struct btf and btf_id() */ +#include <linux/filter.h> /* for MAX_BPF_STACK */ +#include <linux/tnum.h> + +/* Maximum variable offset umax_value permitted when resolving memory accesses. + * In practice this is far bigger than any realistic pointer offset; this limit + * ensures that umax_value + (int)off + (int)size cannot overflow a u64. + */ +#define BPF_MAX_VAR_OFF (1 << 29) +/* Maximum variable size permitted for ARG_CONST_SIZE[_OR_ZERO]. This ensures + * that converting umax_value to int cannot overflow. + */ +#define BPF_MAX_VAR_SIZ (1 << 29) +/* size of type_str_buf in bpf_verifier. */ +#define TYPE_STR_BUF_LEN 64 + +/* Liveness marks, used for registers and spilled-regs (in stack slots). + * Read marks propagate upwards until they find a write mark; they record that + * "one of this state's descendants read this reg" (and therefore the reg is + * relevant for states_equal() checks). + * Write marks collect downwards and do not propagate; they record that "the + * straight-line code that reached this state (from its parent) wrote this reg" + * (and therefore that reads propagated from this state or its descendants + * should not propagate to its parent). + * A state with a write mark can receive read marks; it just won't propagate + * them to its parent, since the write mark is a property, not of the state, + * but of the link between it and its parent. See mark_reg_read() and + * mark_stack_slot_read() in kernel/bpf/verifier.c. + */ +enum bpf_reg_liveness { + REG_LIVE_NONE = 0, /* reg hasn't been read or written this branch */ + REG_LIVE_READ32 = 0x1, /* reg was read, so we're sensitive to initial value */ + REG_LIVE_READ64 = 0x2, /* likewise, but full 64-bit content matters */ + REG_LIVE_READ = REG_LIVE_READ32 | REG_LIVE_READ64, + REG_LIVE_WRITTEN = 0x4, /* reg was written first, screening off later reads */ + REG_LIVE_DONE = 0x8, /* liveness won't be updating this register anymore */ +}; + +struct bpf_reg_state { + /* Ordering of fields matters. See states_equal() */ + enum bpf_reg_type type; + /* Fixed part of pointer offset, pointer types only */ + s32 off; + union { + /* valid when type == PTR_TO_PACKET */ + int range; + + /* valid when type == CONST_PTR_TO_MAP | PTR_TO_MAP_VALUE | + * PTR_TO_MAP_VALUE_OR_NULL + */ + struct { + struct bpf_map *map_ptr; + /* To distinguish map lookups from outer map + * the map_uid is non-zero for registers + * pointing to inner maps. + */ + u32 map_uid; + }; + + /* for PTR_TO_BTF_ID */ + struct { + struct btf *btf; + u32 btf_id; + }; + + u32 mem_size; /* for PTR_TO_MEM | PTR_TO_MEM_OR_NULL */ + + /* For dynptr stack slots */ + struct { + enum bpf_dynptr_type type; + /* A dynptr is 16 bytes so it takes up 2 stack slots. + * We need to track which slot is the first slot + * to protect against cases where the user may try to + * pass in an address starting at the second slot of the + * dynptr. + */ + bool first_slot; + } dynptr; + + /* Max size from any of the above. */ + struct { + unsigned long raw1; + unsigned long raw2; + } raw; + + u32 subprogno; /* for PTR_TO_FUNC */ + }; + /* For PTR_TO_PACKET, used to find other pointers with the same variable + * offset, so they can share range knowledge. + * For PTR_TO_MAP_VALUE_OR_NULL this is used to share which map value we + * came from, when one is tested for != NULL. + * For PTR_TO_MEM_OR_NULL this is used to identify memory allocation + * for the purpose of tracking that it's freed. + * For PTR_TO_SOCKET this is used to share which pointers retain the + * same reference to the socket, to determine proper reference freeing. + * For stack slots that are dynptrs, this is used to track references to + * the dynptr to determine proper reference freeing. + */ + u32 id; + /* PTR_TO_SOCKET and PTR_TO_TCP_SOCK could be a ptr returned + * from a pointer-cast helper, bpf_sk_fullsock() and + * bpf_tcp_sock(). + * + * Consider the following where "sk" is a reference counted + * pointer returned from "sk = bpf_sk_lookup_tcp();": + * + * 1: sk = bpf_sk_lookup_tcp(); + * 2: if (!sk) { return 0; } + * 3: fullsock = bpf_sk_fullsock(sk); + * 4: if (!fullsock) { bpf_sk_release(sk); return 0; } + * 5: tp = bpf_tcp_sock(fullsock); + * 6: if (!tp) { bpf_sk_release(sk); return 0; } + * 7: bpf_sk_release(sk); + * 8: snd_cwnd = tp->snd_cwnd; // verifier will complain + * + * After bpf_sk_release(sk) at line 7, both "fullsock" ptr and + * "tp" ptr should be invalidated also. In order to do that, + * the reg holding "fullsock" and "sk" need to remember + * the original refcounted ptr id (i.e. sk_reg->id) in ref_obj_id + * such that the verifier can reset all regs which have + * ref_obj_id matching the sk_reg->id. + * + * sk_reg->ref_obj_id is set to sk_reg->id at line 1. + * sk_reg->id will stay as NULL-marking purpose only. + * After NULL-marking is done, sk_reg->id can be reset to 0. + * + * After "fullsock = bpf_sk_fullsock(sk);" at line 3, + * fullsock_reg->ref_obj_id is set to sk_reg->ref_obj_id. + * + * After "tp = bpf_tcp_sock(fullsock);" at line 5, + * tp_reg->ref_obj_id is set to fullsock_reg->ref_obj_id + * which is the same as sk_reg->ref_obj_id. + * + * From the verifier perspective, if sk, fullsock and tp + * are not NULL, they are the same ptr with different + * reg->type. In particular, bpf_sk_release(tp) is also + * allowed and has the same effect as bpf_sk_release(sk). + */ + u32 ref_obj_id; + /* For scalar types (SCALAR_VALUE), this represents our knowledge of + * the actual value. + * For pointer types, this represents the variable part of the offset + * from the pointed-to object, and is shared with all bpf_reg_states + * with the same id as us. + */ + struct tnum var_off; + /* Used to determine if any memory access using this register will + * result in a bad access. + * These refer to the same value as var_off, not necessarily the actual + * contents of the register. + */ + s64 smin_value; /* minimum possible (s64)value */ + s64 smax_value; /* maximum possible (s64)value */ + u64 umin_value; /* minimum possible (u64)value */ + u64 umax_value; /* maximum possible (u64)value */ + s32 s32_min_value; /* minimum possible (s32)value */ + s32 s32_max_value; /* maximum possible (s32)value */ + u32 u32_min_value; /* minimum possible (u32)value */ + u32 u32_max_value; /* maximum possible (u32)value */ + /* parentage chain for liveness checking */ + struct bpf_reg_state *parent; + /* Inside the callee two registers can be both PTR_TO_STACK like + * R1=fp-8 and R2=fp-8, but one of them points to this function stack + * while another to the caller's stack. To differentiate them 'frameno' + * is used which is an index in bpf_verifier_state->frame[] array + * pointing to bpf_func_state. + */ + u32 frameno; + /* Tracks subreg definition. The stored value is the insn_idx of the + * writing insn. This is safe because subreg_def is used before any insn + * patching which only happens after main verification finished. + */ + s32 subreg_def; + enum bpf_reg_liveness live; + /* if (!precise && SCALAR_VALUE) min/max/tnum don't affect safety */ + bool precise; +}; + +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 */ + STACK_ZERO, /* BPF program wrote constant zero */ + /* A dynptr is stored in this stack slot. The type of dynptr + * is stored in bpf_stack_state->spilled_ptr.dynptr.type + */ + STACK_DYNPTR, +}; + +#define BPF_REG_SIZE 8 /* size of eBPF register in bytes */ +#define BPF_DYNPTR_SIZE sizeof(struct bpf_dynptr_kern) +#define BPF_DYNPTR_NR_SLOTS (BPF_DYNPTR_SIZE / BPF_REG_SIZE) + +struct bpf_stack_state { + struct bpf_reg_state spilled_ptr; + u8 slot_type[BPF_REG_SIZE]; +}; + +struct bpf_reference_state { + /* Track each reference created with a unique id, even if the same + * instruction creates the reference multiple times (eg, via CALL). + */ + int id; + /* Instruction where the allocation of this reference occurred. This + * is used purely to inform the user of a reference leak. + */ + int insn_idx; + /* There can be a case like: + * main (frame 0) + * cb (frame 1) + * func (frame 3) + * cb (frame 4) + * Hence for frame 4, if callback_ref just stored boolean, it would be + * impossible to distinguish nested callback refs. Hence store the + * frameno and compare that to callback_ref in check_reference_leak when + * exiting a callback function. + */ + int callback_ref; +}; + +/* state of the program: + * type of all registers and stack info + */ +struct bpf_func_state { + struct bpf_reg_state regs[MAX_BPF_REG]; + /* index of call instruction that called into this func */ + int callsite; + /* stack frame number of this function state from pov of + * enclosing bpf_verifier_state. + * 0 = main function, 1 = first callee. + */ + u32 frameno; + /* subprog number == index within subprog_info + * zero == main subprog + */ + u32 subprogno; + /* Every bpf_timer_start will increment async_entry_cnt. + * It's used to distinguish: + * void foo(void) { for(;;); } + * void foo(void) { bpf_timer_set_callback(,foo); } + */ + u32 async_entry_cnt; + bool in_callback_fn; + struct tnum callback_ret_range; + bool in_async_callback_fn; + + /* The following fields should be last. See copy_func_state() */ + int acquired_refs; + struct bpf_reference_state *refs; + int allocated_stack; + struct bpf_stack_state *stack; +}; + +struct bpf_idx_pair { + u32 prev_idx; + u32 idx; +}; + +struct bpf_id_pair { + u32 old; + u32 cur; +}; + +/* Maximum number of register states that can exist at once */ +#define BPF_ID_MAP_SIZE (MAX_BPF_REG + MAX_BPF_STACK / BPF_REG_SIZE) +#define MAX_CALL_FRAMES 8 +struct bpf_verifier_state { + /* call stack tracking */ + struct bpf_func_state *frame[MAX_CALL_FRAMES]; + struct bpf_verifier_state *parent; + /* + * 'branches' field is the number of branches left to explore: + * 0 - all possible paths from this state reached bpf_exit or + * were safely pruned + * 1 - at least one path is being explored. + * This state hasn't reached bpf_exit + * 2 - at least two paths are being explored. + * This state is an immediate parent of two children. + * One is fallthrough branch with branches==1 and another + * state is pushed into stack (to be explored later) also with + * branches==1. The parent of this state has branches==1. + * The verifier state tree connected via 'parent' pointer looks like: + * 1 + * 1 + * 2 -> 1 (first 'if' pushed into stack) + * 1 + * 2 -> 1 (second 'if' pushed into stack) + * 1 + * 1 + * 1 bpf_exit. + * + * Once do_check() reaches bpf_exit, it calls update_branch_counts() + * and the verifier state tree will look: + * 1 + * 1 + * 2 -> 1 (first 'if' pushed into stack) + * 1 + * 1 -> 1 (second 'if' pushed into stack) + * 0 + * 0 + * 0 bpf_exit. + * After pop_stack() the do_check() will resume at second 'if'. + * + * If is_state_visited() sees a state with branches > 0 it means + * there is a loop. If such state is exactly equal to the current state + * it's an infinite loop. Note states_equal() checks for states + * equivalency, so two states being 'states_equal' does not mean + * infinite loop. The exact comparison is provided by + * states_maybe_looping() function. It's a stronger pre-check and + * much faster than states_equal(). + * + * This algorithm may not find all possible infinite loops or + * loop iteration count may be too high. + * In such cases BPF_COMPLEXITY_LIMIT_INSNS limit kicks in. + */ + u32 branches; + u32 insn_idx; + u32 curframe; + u32 active_spin_lock; + bool speculative; + + /* first and last insn idx of this verifier state */ + u32 first_insn_idx; + u32 last_insn_idx; + /* jmp history recorded from first to last. + * backtracking is using it to go from last to first. + * For most states jmp_history_cnt is [0-3]. + * For loops can go up to ~40. + */ + struct bpf_idx_pair *jmp_history; + u32 jmp_history_cnt; +}; + +#define bpf_get_spilled_reg(slot, frame) \ + (((slot < frame->allocated_stack / BPF_REG_SIZE) && \ + (frame->stack[slot].slot_type[0] == STACK_SPILL)) \ + ? &frame->stack[slot].spilled_ptr : NULL) + +/* Iterate over 'frame', setting 'reg' to either NULL or a spilled register. */ +#define bpf_for_each_spilled_reg(iter, frame, reg) \ + for (iter = 0, reg = bpf_get_spilled_reg(iter, frame); \ + iter < frame->allocated_stack / BPF_REG_SIZE; \ + iter++, reg = bpf_get_spilled_reg(iter, frame)) + +/* Invoke __expr over regsiters in __vst, setting __state and __reg */ +#define bpf_for_each_reg_in_vstate(__vst, __state, __reg, __expr) \ + ({ \ + struct bpf_verifier_state *___vstate = __vst; \ + int ___i, ___j; \ + for (___i = 0; ___i <= ___vstate->curframe; ___i++) { \ + struct bpf_reg_state *___regs; \ + __state = ___vstate->frame[___i]; \ + ___regs = __state->regs; \ + for (___j = 0; ___j < MAX_BPF_REG; ___j++) { \ + __reg = &___regs[___j]; \ + (void)(__expr); \ + } \ + bpf_for_each_spilled_reg(___j, __state, __reg) { \ + if (!__reg) \ + continue; \ + (void)(__expr); \ + } \ + } \ + }) + +/* linked list of verifier states used to prune search */ +struct bpf_verifier_state_list { + struct bpf_verifier_state state; + struct bpf_verifier_state_list *next; + int miss_cnt, hit_cnt; +}; + +struct bpf_loop_inline_state { + unsigned int initialized:1; /* set to true upon first entry */ + unsigned int fit_for_inline:1; /* true if callback function is the same + * at each call and flags are always zero + */ + u32 callback_subprogno; /* valid when fit_for_inline is true */ +}; + +/* Possible states for alu_state member. */ +#define BPF_ALU_SANITIZE_SRC (1U << 0) +#define BPF_ALU_SANITIZE_DST (1U << 1) +#define BPF_ALU_NEG_VALUE (1U << 2) +#define BPF_ALU_NON_POINTER (1U << 3) +#define BPF_ALU_IMMEDIATE (1U << 4) +#define BPF_ALU_SANITIZE (BPF_ALU_SANITIZE_SRC | \ + BPF_ALU_SANITIZE_DST) + +struct bpf_insn_aux_data { + union { + enum bpf_reg_type ptr_type; /* pointer type for load/store insns */ + unsigned long map_ptr_state; /* pointer/poison value for maps */ + s32 call_imm; /* saved imm field of call insn */ + u32 alu_limit; /* limit for add/sub register with pointer */ + struct { + u32 map_index; /* index into used_maps[] */ + u32 map_off; /* offset from value base address */ + }; + struct { + enum bpf_reg_type reg_type; /* type of pseudo_btf_id */ + union { + struct { + struct btf *btf; + u32 btf_id; /* btf_id for struct typed var */ + }; + u32 mem_size; /* mem_size for non-struct typed var */ + }; + } btf_var; + /* if instruction is a call to bpf_loop this field tracks + * the state of the relevant registers to make decision about inlining + */ + struct bpf_loop_inline_state loop_inline_state; + }; + u64 map_key_state; /* constant (32 bit) key tracking for maps */ + int ctx_field_size; /* the ctx field size for load insn, maybe 0 */ + u32 seen; /* this insn was processed by the verifier at env->pass_cnt */ + bool sanitize_stack_spill; /* subject to Spectre v4 sanitation */ + bool zext_dst; /* this insn zero extends dst reg */ + u8 alu_state; /* used in combination with alu_limit */ + + /* below fields are initialized once */ + unsigned int orig_idx; /* original instruction index */ + bool prune_point; + bool jmp_point; +}; + +#define MAX_USED_MAPS 64 /* max number of maps accessed by one eBPF program */ +#define MAX_USED_BTFS 64 /* max number of BTFs accessed by one BPF program */ + +#define BPF_VERIFIER_TMP_LOG_SIZE 1024 + +struct bpf_verifier_log { + u32 level; + char kbuf[BPF_VERIFIER_TMP_LOG_SIZE]; + char __user *ubuf; + u32 len_used; + u32 len_total; +}; + +static inline bool bpf_verifier_log_full(const struct bpf_verifier_log *log) +{ + return log->len_used >= log->len_total - 1; +} + +#define BPF_LOG_LEVEL1 1 +#define BPF_LOG_LEVEL2 2 +#define BPF_LOG_STATS 4 +#define BPF_LOG_LEVEL (BPF_LOG_LEVEL1 | BPF_LOG_LEVEL2) +#define BPF_LOG_MASK (BPF_LOG_LEVEL | BPF_LOG_STATS) +#define BPF_LOG_KERNEL (BPF_LOG_MASK + 1) /* kernel internal flag */ +#define BPF_LOG_MIN_ALIGNMENT 8U +#define BPF_LOG_ALIGNMENT 40U + +static inline bool bpf_verifier_log_needed(const struct bpf_verifier_log *log) +{ + return log && + ((log->level && log->ubuf && !bpf_verifier_log_full(log)) || + log->level == BPF_LOG_KERNEL); +} + +static inline bool +bpf_verifier_log_attr_valid(const struct bpf_verifier_log *log) +{ + return log->len_total >= 128 && log->len_total <= UINT_MAX >> 2 && + log->level && log->ubuf && !(log->level & ~BPF_LOG_MASK); +} + +#define BPF_MAX_SUBPROGS 256 + +struct bpf_subprog_info { + /* 'start' has to be the first field otherwise find_subprog() won't work */ + u32 start; /* insn idx of function entry point */ + u32 linfo_idx; /* The idx to the main_prog->aux->linfo */ + u16 stack_depth; /* max. stack depth used by this function */ + bool has_tail_call; + bool tail_call_reachable; + bool has_ld_abs; + bool is_async_cb; +}; + +/* single container for all structs + * one verifier_env per bpf_check() call + */ +struct bpf_verifier_env { + u32 insn_idx; + u32 prev_insn_idx; + struct bpf_prog *prog; /* eBPF program being verified */ + const struct bpf_verifier_ops *ops; + struct bpf_verifier_stack_elem *head; /* stack of verifier states to be processed */ + int stack_size; /* number of states to be processed */ + bool strict_alignment; /* perform strict pointer alignment checks */ + bool test_state_freq; /* test verifier with different pruning frequency */ + struct bpf_verifier_state *cur_state; /* current verifier state */ + struct bpf_verifier_state_list **explored_states; /* search pruning optimization */ + struct bpf_verifier_state_list *free_list; + struct bpf_map *used_maps[MAX_USED_MAPS]; /* array of map's used by eBPF program */ + struct btf_mod_pair used_btfs[MAX_USED_BTFS]; /* array of BTF's used by BPF program */ + u32 used_map_cnt; /* number of used maps */ + u32 used_btf_cnt; /* number of used BTF objects */ + u32 id_gen; /* used to generate unique reg IDs */ + bool explore_alu_limits; + bool allow_ptr_leaks; + bool allow_uninit_stack; + bool allow_ptr_to_map_access; + bool bpf_capable; + bool bypass_spec_v1; + bool bypass_spec_v4; + bool seen_direct_write; + struct bpf_insn_aux_data *insn_aux_data; /* array of per-insn state */ + const struct bpf_line_info *prev_linfo; + struct bpf_verifier_log log; + struct bpf_subprog_info subprog_info[BPF_MAX_SUBPROGS + 1]; + struct bpf_id_pair idmap_scratch[BPF_ID_MAP_SIZE]; + struct { + int *insn_state; + int *insn_stack; + int cur_stack; + } cfg; + u32 pass_cnt; /* number of times do_check() was called */ + u32 subprog_cnt; + /* number of instructions analyzed by the verifier */ + u32 prev_insn_processed, insn_processed; + /* number of jmps, calls, exits analyzed so far */ + u32 prev_jmps_processed, jmps_processed; + /* total verification time */ + u64 verification_time; + /* maximum number of verifier states kept in 'branching' instructions */ + u32 max_states_per_insn; + /* total number of allocated verifier states */ + u32 total_states; + /* some states are freed during program analysis. + * this is peak number of states. this number dominates kernel + * memory consumption during verification + */ + u32 peak_states; + /* longest register parentage chain walked for liveness marking */ + u32 longest_mark_read_walk; + bpfptr_t fd_array; + + /* bit mask to keep track of whether a register has been accessed + * since the last time the function state was printed + */ + u32 scratched_regs; + /* Same as scratched_regs but for stack slots */ + u64 scratched_stack_slots; + u32 prev_log_len, prev_insn_print_len; + /* buffer used in reg_type_str() to generate reg_type string */ + char type_str_buf[TYPE_STR_BUF_LEN]; +}; + +__printf(2, 0) void bpf_verifier_vlog(struct bpf_verifier_log *log, + const char *fmt, va_list args); +__printf(2, 3) void bpf_verifier_log_write(struct bpf_verifier_env *env, + const char *fmt, ...); +__printf(2, 3) void bpf_log(struct bpf_verifier_log *log, + const char *fmt, ...); + +static inline struct bpf_func_state *cur_func(struct bpf_verifier_env *env) +{ + struct bpf_verifier_state *cur = env->cur_state; + + return cur->frame[cur->curframe]; +} + +static inline struct bpf_reg_state *cur_regs(struct bpf_verifier_env *env) +{ + return cur_func(env)->regs; +} + +int bpf_prog_offload_verifier_prep(struct bpf_prog *prog); +int bpf_prog_offload_verify_insn(struct bpf_verifier_env *env, + int insn_idx, int prev_insn_idx); +int bpf_prog_offload_finalize(struct bpf_verifier_env *env); +void +bpf_prog_offload_replace_insn(struct bpf_verifier_env *env, u32 off, + struct bpf_insn *insn); +void +bpf_prog_offload_remove_insns(struct bpf_verifier_env *env, u32 off, u32 cnt); + +int check_ptr_off_reg(struct bpf_verifier_env *env, + const struct bpf_reg_state *reg, int regno); +int check_func_arg_reg_off(struct bpf_verifier_env *env, + const struct bpf_reg_state *reg, int regno, + enum bpf_arg_type arg_type); +int check_kfunc_mem_size_reg(struct bpf_verifier_env *env, struct bpf_reg_state *reg, + u32 regno); +int check_mem_reg(struct bpf_verifier_env *env, struct bpf_reg_state *reg, + u32 regno, u32 mem_size); +bool is_dynptr_reg_valid_init(struct bpf_verifier_env *env, + struct bpf_reg_state *reg); +bool is_dynptr_type_expected(struct bpf_verifier_env *env, + struct bpf_reg_state *reg, + enum bpf_arg_type arg_type); + +/* this lives here instead of in bpf.h because it needs to dereference tgt_prog */ +static inline u64 bpf_trampoline_compute_key(const struct bpf_prog *tgt_prog, + struct btf *btf, u32 btf_id) +{ + if (tgt_prog) + return ((u64)tgt_prog->aux->id << 32) | btf_id; + else + return ((u64)btf_obj_id(btf) << 32) | 0x80000000 | btf_id; +} + +/* unpack the IDs from the key as constructed above */ +static inline void bpf_trampoline_unpack_key(u64 key, u32 *obj_id, u32 *btf_id) +{ + if (obj_id) + *obj_id = key >> 32; + if (btf_id) + *btf_id = key & 0x7FFFFFFF; +} + +int bpf_check_attach_target(struct bpf_verifier_log *log, + const struct bpf_prog *prog, + const struct bpf_prog *tgt_prog, + u32 btf_id, + struct bpf_attach_target_info *tgt_info); +void bpf_free_kfunc_btf_tab(struct bpf_kfunc_btf_tab *tab); + +int mark_chain_precision(struct bpf_verifier_env *env, int regno); + +#define BPF_BASE_TYPE_MASK GENMASK(BPF_BASE_TYPE_BITS - 1, 0) + +/* extract base type from bpf_{arg, return, reg}_type. */ +static inline u32 base_type(u32 type) +{ + return type & BPF_BASE_TYPE_MASK; +} + +/* extract flags from an extended type. See bpf_type_flag in bpf.h. */ +static inline u32 type_flag(u32 type) +{ + return type & ~BPF_BASE_TYPE_MASK; +} + +/* only use after check_attach_btf_id() */ +static inline enum bpf_prog_type resolve_prog_type(const struct bpf_prog *prog) +{ + return prog->type == BPF_PROG_TYPE_EXT ? + prog->aux->dst_prog->type : prog->type; +} + +static inline bool bpf_prog_check_recur(const struct bpf_prog *prog) +{ + switch (resolve_prog_type(prog)) { + case BPF_PROG_TYPE_TRACING: + return prog->expected_attach_type != BPF_TRACE_ITER; + case BPF_PROG_TYPE_STRUCT_OPS: + case BPF_PROG_TYPE_LSM: + return false; + default: + return true; + } +} + +#endif /* _LINUX_BPF_VERIFIER_H */ |