93 lines · c
1/* SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause) */2/* Copyright (c) 2024 Meta Platforms, Inc. and affiliates. */3#pragma once4#include "bpf_arena_common.h"5 6struct arena_list_node;7 8typedef struct arena_list_node __arena arena_list_node_t;9 10struct arena_list_node {11 arena_list_node_t *next;12 arena_list_node_t * __arena *pprev;13};14 15struct arena_list_head {16 struct arena_list_node __arena *first;17};18typedef struct arena_list_head __arena arena_list_head_t;19 20#define list_entry(ptr, type, member) arena_container_of(ptr, type, member)21 22#define list_entry_safe(ptr, type, member) \23 ({ typeof(*ptr) * ___ptr = (ptr); \24 ___ptr ? ({ cast_kern(___ptr); list_entry(___ptr, type, member); }) : NULL; \25 })26 27#ifndef __BPF__28static inline void *bpf_iter_num_new(struct bpf_iter_num *it, int i, int j) { return NULL; }29static inline void bpf_iter_num_destroy(struct bpf_iter_num *it) {}30static inline bool bpf_iter_num_next(struct bpf_iter_num *it) { return true; }31#define cond_break ({})32#define can_loop true33#endif34 35/* Safely walk link list elements. Deletion of elements is allowed. */36#define list_for_each_entry(pos, head, member) \37 for (void * ___tmp = (pos = list_entry_safe((head)->first, \38 typeof(*(pos)), member), \39 (void *)0); \40 pos && ({ ___tmp = (void *)pos->member.next; 1; }) && can_loop; \41 pos = list_entry_safe((void __arena *)___tmp, typeof(*(pos)), member))42 43static inline void list_add_head(arena_list_node_t *n, arena_list_head_t *h)44{45 arena_list_node_t *first = h->first, * __arena *tmp;46 47 cast_user(first);48 cast_kern(n);49 WRITE_ONCE(n->next, first);50 cast_kern(first);51 if (first) {52 tmp = &n->next;53 cast_user(tmp);54 WRITE_ONCE(first->pprev, tmp);55 }56 cast_user(n);57 WRITE_ONCE(h->first, n);58 59 tmp = &h->first;60 cast_user(tmp);61 cast_kern(n);62 WRITE_ONCE(n->pprev, tmp);63}64 65static inline void __list_del(arena_list_node_t *n)66{67 arena_list_node_t *next = n->next, *tmp;68 arena_list_node_t * __arena *pprev = n->pprev;69 70 cast_user(next);71 cast_kern(pprev);72 tmp = *pprev;73 cast_kern(tmp);74 WRITE_ONCE(tmp, next);75 if (next) {76 cast_user(pprev);77 cast_kern(next);78 WRITE_ONCE(next->pprev, pprev);79 }80}81 82#define POISON_POINTER_DELTA 083 84#define LIST_POISON1 ((void __arena *) 0x100 + POISON_POINTER_DELTA)85#define LIST_POISON2 ((void __arena *) 0x122 + POISON_POINTER_DELTA)86 87static inline void list_del(arena_list_node_t *n)88{89 __list_del(n);90 n->next = LIST_POISON1;91 n->pprev = LIST_POISON2;92}93