/* Copyright (c) 2011-2014 PLUMgrid, http://plumgrid.com * Copyright (c) 2016,2017 Facebook * * This program is free software; you can redistribute it and/or * modify it under the terms of version 2 of the GNU General Public * License as published by the Free Software Foundation. * * This program is distributed in the hope that it will be useful, but * WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * General Public License for more details. */#include <linux/bpf.h>#include <linux/err.h>#include <linux/slab.h>#include <linux/mm.h>#include <linux/filter.h>#include <linux/perf_event.h> #include "map_in_map.h" #define ARRAY_CREATE_FLAG_MASK \	(BPF_F_NUMA_NODE | BPF_F_RDONLY | BPF_F_WRONLY) static void bpf_array_free_percpu(struct bpf_array *array){	int i; 	for (i = 0; i < array->map.max_entries; i++)		free_percpu(array->pptrs[i]);} static int bpf_array_alloc_percpu(struct bpf_array *array){	void __percpu *ptr;	int i; 	for (i = 0; i < array->map.max_entries; i++) {		ptr = __alloc_percpu_gfp(array->elem_size, 8,					 GFP_USER | __GFP_NOWARN);		if (!ptr) {			bpf_array_free_percpu(array);			return -ENOMEM;		}		array->pptrs[i] = ptr;	} 	return 0;} /* Called from syscall */static struct bpf_map *array_map_alloc(union bpf_attr *attr){	bool percpu = attr->map_type == BPF_MAP_TYPE_PERCPU_ARRAY;	int numa_node = bpf_map_attr_numa_node(attr);	u32 elem_size, index_mask, max_entries;	bool unpriv = !capable(CAP_SYS_ADMIN);	struct bpf_array *array;	u64 array_size; 	/* check sanity of attributes */	if (attr->max_entries == 0 || attr->key_size != 4 ||	    attr->value_size == 0 ||	    attr->map_flags & ~ARRAY_CREATE_FLAG_MASK ||	    (percpu && numa_node != NUMA_NO_NODE))		return ERR_PTR(-EINVAL); 	if (attr->value_size > KMALLOC_MAX_SIZE)		/* if value_size is bigger, the user space won't be able to		 * access the elements.		 */		return ERR_PTR(-E2BIG); 	elem_size = round_up(attr->value_size, 8); 	max_entries = attr->max_entries;	index_mask = roundup_pow_of_two(max_entries) - 1; 	if (unpriv)		/* round up array size to nearest power of 2,		 * since cpu will speculate within index_mask limits		 */		max_entries = index_mask + 1; 	array_size = sizeof(*array);	if (percpu)		array_size += (u64) max_entries * sizeof(void *);	else		array_size += (u64) max_entries * elem_size; 	/* make sure there is no u32 overflow later in round_up() */	if (array_size >= U32_MAX - PAGE_SIZE)		return ERR_PTR(-ENOMEM); 	/* allocate all map elements and zero-initialize them */	array = bpf_map_area_alloc(array_size, numa_node);	if (!array)		return ERR_PTR(-ENOMEM);	array->index_mask = index_mask;	array->map.unpriv_array = unpriv; 	/* copy mandatory map attributes */	array->map.map_type = attr->map_type;	array->map.key_size = attr->key_size;	array->map.value_size = attr->value_size;	array->map.max_entries = attr->max_entries;	array->map.map_flags = attr->map_flags;	array->map.numa_node = numa_node;	array->elem_size = elem_size; 	if (!percpu)		goto out; 	array_size += (u64) attr->max_entries * elem_size * num_possible_cpus(); 	if (array_size >= U32_MAX - PAGE_SIZE ||	    bpf_array_alloc_percpu(array)) {		bpf_map_area_free(array);		return ERR_PTR(-ENOMEM);	}out:	array->map.pages = round_up(array_size, PAGE_SIZE) >> PAGE_SHIFT; 	return &array->map;} /* Called from syscall or from eBPF program */static void *array_map_lookup_elem(struct bpf_map *map, void *key){	struct bpf_array *array = container_of(map, struct bpf_array, map);	u32 index = *(u32 *)key; 	if (unlikely(index >= array->map.max_entries))		return NULL; 	return array->value + array->elem_size * (index & array->index_mask);} /* emit BPF instructions equivalent to C code of array_map_lookup_elem() */static u32 array_map_gen_lookup(struct bpf_map *map, struct bpf_insn *insn_buf){	struct bpf_array *array = container_of(map, struct bpf_array, map);	struct bpf_insn *insn = insn_buf;	u32 elem_size = round_up(map->value_size, 8);	const int ret = BPF_REG_0;	const int map_ptr = BPF_REG_1;	const int index = BPF_REG_2; 	*insn++ = BPF_ALU64_IMM(BPF_ADD, map_ptr, offsetof(struct bpf_array, value));	*insn++ = BPF_LDX_MEM(BPF_W, ret, index, 0);	if (map->unpriv_array) {		*insn++ = BPF_JMP_IMM(BPF_JGE, ret, map->max_entries, 4);		*insn++ = BPF_ALU32_IMM(BPF_AND, ret, array->index_mask);	} else {		*insn++ = BPF_JMP_IMM(BPF_JGE, ret, map->max_entries, 3);	} 	if (is_power_of_2(elem_size)) {		*insn++ = BPF_ALU64_IMM(BPF_LSH, ret, ilog2(elem_size));	} else {		*insn++ = BPF_ALU64_IMM(BPF_MUL, ret, elem_size);	}	*insn++ = BPF_ALU64_REG(BPF_ADD, ret, map_ptr);	*insn++ = BPF_JMP_IMM(BPF_JA, 0, 0, 1);	*insn++ = BPF_MOV64_IMM(ret, 0);	return insn - insn_buf;} /* Called from eBPF program */static void *percpu_array_map_lookup_elem(struct bpf_map *map, void *key){	struct bpf_array *array = container_of(map, struct bpf_array, map);	u32 index = *(u32 *)key; 	if (unlikely(index >= array->map.max_entries))		return NULL; 	return this_cpu_ptr(array->pptrs[index & array->index_mask]);} int bpf_percpu_array_copy(struct bpf_map *map, void *key, void *value){	struct bpf_array *array = container_of(map, struct bpf_array, map);	u32 index = *(u32 *)key;	void __percpu *pptr;	int cpu, off = 0;	u32 size; 	if (unlikely(index >= array->map.max_entries))		return -ENOENT; 	/* per_cpu areas are zero-filled and bpf programs can only	 * access 'value_size' of them, so copying rounded areas	 * will not leak any kernel data	 */	size = round_up(map->value_size, 8);	rcu_read_lock();	pptr = array->pptrs[index & array->index_mask];	for_each_possible_cpu(cpu) {		bpf_long_memcpy(value + off, per_cpu_ptr(pptr, cpu), size);		off += size;	}	rcu_read_unlock();	return 0;} /* Called from syscall */static int array_map_get_next_key(struct bpf_map *map, void *key, void *next_key){	struct bpf_array *array = container_of(map, struct bpf_array, map);	u32 index = key ? *(u32 *)key : U32_MAX;	u32 *next = (u32 *)next_key; 	if (index >= array->map.max_entries) {		*next = 0;		return 0;	} 	if (index == array->map.max_entries - 1)		return -ENOENT; 	*next = index + 1;	return 0;} /* Called from syscall or from eBPF program */static int array_map_update_elem(struct bpf_map *map, void *key, void *value,				 u64 map_flags){	struct bpf_array *array = container_of(map, struct bpf_array, map);	u32 index = *(u32 *)key; 	if (unlikely(map_flags > BPF_EXIST))		/* unknown flags */		return -EINVAL; 	if (unlikely(index >= array->map.max_entries))		/* all elements were pre-allocated, cannot insert a new one */		return -E2BIG; 	if (unlikely(map_flags == BPF_NOEXIST))		/* all elements already exist */		return -EEXIST; 	if (array->map.map_type == BPF_MAP_TYPE_PERCPU_ARRAY)		memcpy(this_cpu_ptr(array->pptrs[index & array->index_mask]),		       value, map->value_size);	else		memcpy(array->value +		       array->elem_size * (index & array->index_mask),		       value, map->value_size);	return 0;} int bpf_percpu_array_update(struct bpf_map *map, void *key, void *value,			    u64 map_flags){	struct bpf_array *array = container_of(map, struct bpf_array, map);	u32 index = *(u32 *)key;	void __percpu *pptr;	int cpu, off = 0;	u32 size; 	if (unlikely(map_flags > BPF_EXIST))		/* unknown flags */		return -EINVAL; 	if (unlikely(index >= array->map.max_entries))		/* all elements were pre-allocated, cannot insert a new one */		return -E2BIG; 	if (unlikely(map_flags == BPF_NOEXIST))		/* all elements already exist */		return -EEXIST; 	/* the user space will provide round_up(value_size, 8) bytes that	 * will be copied into per-cpu area. bpf programs can only access	 * value_size of it. During lookup the same extra bytes will be	 * returned or zeros which were zero-filled by percpu_alloc,	 * so no kernel data leaks possible	 */	size = round_up(map->value_size, 8);	rcu_read_lock();	pptr = array->pptrs[index & array->index_mask];	for_each_possible_cpu(cpu) {		bpf_long_memcpy(per_cpu_ptr(pptr, cpu), value + off, size);		off += size;	}	rcu_read_unlock();	return 0;} /* Called from syscall or from eBPF program */static int array_map_delete_elem(struct bpf_map *map, void *key){	return -EINVAL;} /* Called when map->refcnt goes to zero, either from workqueue or from syscall */static void array_map_free(struct bpf_map *map){	struct bpf_array *array = container_of(map, struct bpf_array, map); 	/* at this point bpf_prog->aux->refcnt == 0 and this map->refcnt == 0,	 * so the programs (can be more than one that used this map) were	 * disconnected from events. Wait for outstanding programs to complete	 * and free the array	 */	synchronize_rcu(); 	if (array->map.map_type == BPF_MAP_TYPE_PERCPU_ARRAY)		bpf_array_free_percpu(array); 	bpf_map_area_free(array);} const struct bpf_map_ops array_map_ops = {	.map_alloc = array_map_alloc,	.map_free = array_map_free,	.map_get_next_key = array_map_get_next_key,	.map_lookup_elem = array_map_lookup_elem,	.map_update_elem = array_map_update_elem,	.map_delete_elem = array_map_delete_elem,	.map_gen_lookup = array_map_gen_lookup,}; const struct bpf_map_ops percpu_array_map_ops = {	.map_alloc = array_map_alloc,	.map_free = array_map_free,	.map_get_next_key = array_map_get_next_key,	.map_lookup_elem = percpu_array_map_lookup_elem,	.map_update_elem = array_map_update_elem,	.map_delete_elem = array_map_delete_elem,}; static struct bpf_map *fd_array_map_alloc(union bpf_attr *attr){	/* only file descriptors can be stored in this type of map */	if (attr->value_size != sizeof(u32))		return ERR_PTR(-EINVAL);	return array_map_alloc(attr);} static void fd_array_map_free(struct bpf_map *map){	struct bpf_array *array = container_of(map, struct bpf_array, map);	int i; 	synchronize_rcu(); 	/* make sure it's empty */	for (i = 0; i < array->map.max_entries; i++)		BUG_ON(array->ptrs[i] != NULL); 	bpf_map_area_free(array);} static void *fd_array_map_lookup_elem(struct bpf_map *map, void *key){	return NULL;} /* only called from syscall */int bpf_fd_array_map_lookup_elem(struct bpf_map *map, void *key, u32 *value){	void **elem, *ptr;	int ret =  0; 	if (!map->ops->map_fd_sys_lookup_elem)		return -ENOTSUPP; 	rcu_read_lock();	elem = array_map_lookup_elem(map, key);	if (elem && (ptr = READ_ONCE(*elem)))		*value = map->ops->map_fd_sys_lookup_elem(ptr);	else		ret = -ENOENT;	rcu_read_unlock(); 	return ret;} /* only called from syscall */int bpf_fd_array_map_update_elem(struct bpf_map *map, struct file *map_file,				 void *key, void *value, u64 map_flags){	struct bpf_array *array = container_of(map, struct bpf_array, map);	void *new_ptr, *old_ptr;	u32 index = *(u32 *)key, ufd; 	if (map_flags != BPF_ANY)		return -EINVAL; 	if (index >= array->map.max_entries)		return -E2BIG; 	ufd = *(u32 *)value;	new_ptr = map->ops->map_fd_get_ptr(map, map_file, ufd);	if (IS_ERR(new_ptr))		return PTR_ERR(new_ptr); 	old_ptr = xchg(array->ptrs + index, new_ptr);	if (old_ptr)		map->ops->map_fd_put_ptr(old_ptr); 	return 0;} static int fd_array_map_delete_elem(struct bpf_map *map, void *key){	struct bpf_array *array = container_of(map, struct bpf_array, map);	void *old_ptr;	u32 index = *(u32 *)key; 	if (index >= array->map.max_entries)		return -E2BIG; 	old_ptr = xchg(array->ptrs + index, NULL);	if (old_ptr) {		map->ops->map_fd_put_ptr(old_ptr);		return 0;	} else {		return -ENOENT;	}} static void *prog_fd_array_get_ptr(struct bpf_map *map,				   struct file *map_file, int fd){	struct bpf_array *array = container_of(map, struct bpf_array, map);	struct bpf_prog *prog = bpf_prog_get(fd); 	if (IS_ERR(prog))		return prog; 	if (!bpf_prog_array_compatible(array, prog)) {		bpf_prog_put(prog);		return ERR_PTR(-EINVAL);	} 	return prog;} static void prog_fd_array_put_ptr(void *ptr){	bpf_prog_put(ptr);} static u32 prog_fd_array_sys_lookup_elem(void *ptr){	return ((struct bpf_prog *)ptr)->aux->id;} /* decrement refcnt of all bpf_progs that are stored in this map */void bpf_fd_array_map_clear(struct bpf_map *map){	struct bpf_array *array = container_of(map, struct bpf_array, map);	int i; 	for (i = 0; i < array->map.max_entries; i++)		fd_array_map_delete_elem(map, &i);} const struct bpf_map_ops prog_array_map_ops = {	.map_alloc = fd_array_map_alloc,	.map_free = fd_array_map_free,	.map_get_next_key = array_map_get_next_key,	.map_lookup_elem = fd_array_map_lookup_elem,	.map_delete_elem = fd_array_map_delete_elem,	.map_fd_get_ptr = prog_fd_array_get_ptr,	.map_fd_put_ptr = prog_fd_array_put_ptr,	.map_fd_sys_lookup_elem = prog_fd_array_sys_lookup_elem,}; static struct bpf_event_entry *bpf_event_entry_gen(struct file *perf_file,						   struct file *map_file){	struct bpf_event_entry *ee; 	ee = kzalloc(sizeof(*ee), GFP_ATOMIC);	if (ee) {		ee->event = perf_file->private_data;		ee->perf_file = perf_file;		ee->map_file = map_file;	} 	return ee;} static void __bpf_event_entry_free(struct rcu_head *rcu){	struct bpf_event_entry *ee; 	ee = container_of(rcu, struct bpf_event_entry, rcu);	fput(ee->perf_file);	kfree(ee);} static void bpf_event_entry_free_rcu(struct bpf_event_entry *ee){

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