/* 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 128 /* 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 */}; /* For every reg representing a map value or allocated object pointer, * we consider the tuple of (ptr, id) for them to be unique in verifier * context and conside them to not alias each other for the purposes of * tracking lock state. */struct bpf_active_lock {	/* This can either be reg->map_ptr or reg->btf. If ptr is NULL,	 * there's no active lock held, and other fields have no	 * meaning. If non-NULL, it indicates that a lock is held and	 * id member has the reg->id of the register which can be >= 0.	 */	void *ptr;	/* This will be reg->id */	u32 id;}; 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;		}; 		struct { /* for PTR_TO_MEM | PTR_TO_MEM_OR_NULL */			u32 mem_size;			u32 dynptr_id; /* for dynptr slices */		}; 		/* 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 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 */	/* 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;	/* 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;}; #define MAX_CALL_FRAMES 8/* Maximum number of register states that can exist at once */#define BPF_ID_MAP_SIZE ((MAX_BPF_REG + MAX_BPF_STACK / BPF_REG_SIZE) * MAX_CALL_FRAMES)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; 	struct bpf_active_lock active_lock;	bool speculative;	bool active_rcu_lock; 	/* 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 obj_new_size; /* remember the size of type passed to bpf_obj_new to rewrite R1 */	struct btf_struct_meta *kptr_struct_meta;	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 */	bool storage_get_func_atomic; /* bpf_*_storage_get() with atomic memory alloc */	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 boolbpf_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

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