diff options
Diffstat (limited to 'kernel/bpf/syscall.c')
| -rw-r--r-- | kernel/bpf/syscall.c | 5694 |
1 files changed, 4773 insertions, 921 deletions
diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c index b155cd17c1bd..4ff82144f885 100644 --- a/kernel/bpf/syscall.c +++ b/kernel/bpf/syscall.c @@ -1,17 +1,13 @@ +// SPDX-License-Identifier: GPL-2.0-only /* Copyright (c) 2011-2014 PLUMgrid, http://plumgrid.com - * - * 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 <crypto/sha2.h> #include <linux/bpf.h> +#include <linux/bpf-cgroup.h> #include <linux/bpf_trace.h> #include <linux/bpf_lirc.h> +#include <linux/bpf_verifier.h> +#include <linux/bsearch.h> #include <linux/btf.h> #include <linux/syscalls.h> #include <linux/slab.h> @@ -24,38 +20,62 @@ #include <linux/fs.h> #include <linux/license.h> #include <linux/filter.h> -#include <linux/version.h> #include <linux/kernel.h> #include <linux/idr.h> #include <linux/cred.h> #include <linux/timekeeping.h> #include <linux/ctype.h> #include <linux/nospec.h> - -#define IS_FD_ARRAY(map) ((map)->map_type == BPF_MAP_TYPE_PROG_ARRAY || \ - (map)->map_type == BPF_MAP_TYPE_PERF_EVENT_ARRAY || \ - (map)->map_type == BPF_MAP_TYPE_CGROUP_ARRAY || \ - (map)->map_type == BPF_MAP_TYPE_ARRAY_OF_MAPS) +#include <linux/audit.h> +#include <uapi/linux/btf.h> +#include <linux/pgtable.h> +#include <linux/bpf_lsm.h> +#include <linux/poll.h> +#include <linux/sort.h> +#include <linux/bpf-netns.h> +#include <linux/rcupdate_trace.h> +#include <linux/memcontrol.h> +#include <linux/trace_events.h> +#include <linux/tracepoint.h> +#include <linux/overflow.h> +#include <linux/cookie.h> +#include <linux/verification.h> + +#include <net/netfilter/nf_bpf_link.h> +#include <net/netkit.h> +#include <net/tcx.h> + +#define IS_FD_ARRAY(map) ((map)->map_type == BPF_MAP_TYPE_PERF_EVENT_ARRAY || \ + (map)->map_type == BPF_MAP_TYPE_CGROUP_ARRAY || \ + (map)->map_type == BPF_MAP_TYPE_ARRAY_OF_MAPS) +#define IS_FD_PROG_ARRAY(map) ((map)->map_type == BPF_MAP_TYPE_PROG_ARRAY) #define IS_FD_HASH(map) ((map)->map_type == BPF_MAP_TYPE_HASH_OF_MAPS) -#define IS_FD_MAP(map) (IS_FD_ARRAY(map) || IS_FD_HASH(map)) +#define IS_FD_MAP(map) (IS_FD_ARRAY(map) || IS_FD_PROG_ARRAY(map) || \ + IS_FD_HASH(map)) #define BPF_OBJ_FLAG_MASK (BPF_F_RDONLY | BPF_F_WRONLY) DEFINE_PER_CPU(int, bpf_prog_active); +DEFINE_COOKIE(bpf_map_cookie); static DEFINE_IDR(prog_idr); static DEFINE_SPINLOCK(prog_idr_lock); static DEFINE_IDR(map_idr); static DEFINE_SPINLOCK(map_idr_lock); +static DEFINE_IDR(link_idr); +static DEFINE_SPINLOCK(link_idr_lock); -int sysctl_unprivileged_bpf_disabled __read_mostly; +int sysctl_unprivileged_bpf_disabled __read_mostly = + IS_BUILTIN(CONFIG_BPF_UNPRIV_DEFAULT_OFF) ? 2 : 0; static const struct bpf_map_ops * const bpf_map_types[] = { -#define BPF_PROG_TYPE(_id, _ops) +#define BPF_PROG_TYPE(_id, _name, prog_ctx_type, kern_ctx_type) #define BPF_MAP_TYPE(_id, _ops) \ [_id] = &_ops, +#define BPF_LINK_TYPE(_id, _name) #include <linux/bpf_types.h> #undef BPF_PROG_TYPE #undef BPF_MAP_TYPE +#undef BPF_LINK_TYPE }; /* @@ -67,172 +87,358 @@ static const struct bpf_map_ops * const bpf_map_types[] = { * copy_from_user() call. However, this is not a concern since this function is * meant to be a future-proofing of bits. */ -int bpf_check_uarg_tail_zero(void __user *uaddr, +int bpf_check_uarg_tail_zero(bpfptr_t uaddr, size_t expected_size, size_t actual_size) { - unsigned char __user *addr; - unsigned char __user *end; - unsigned char val; - int err; + int res; if (unlikely(actual_size > PAGE_SIZE)) /* silly large */ return -E2BIG; - if (unlikely(!access_ok(uaddr, actual_size))) - return -EFAULT; - if (actual_size <= expected_size) return 0; - addr = uaddr + expected_size; - end = uaddr + actual_size; - - for (; addr < end; addr++) { - err = get_user(val, addr); - if (err) - return err; - if (val) - return -E2BIG; - } - - return 0; + if (uaddr.is_kernel) + res = memchr_inv(uaddr.kernel + expected_size, 0, + actual_size - expected_size) == NULL; + else + res = check_zeroed_user(uaddr.user + expected_size, + actual_size - expected_size); + if (res < 0) + return res; + return res ? 0 : -E2BIG; } const struct bpf_map_ops bpf_map_offload_ops = { + .map_meta_equal = bpf_map_meta_equal, .map_alloc = bpf_map_offload_map_alloc, .map_free = bpf_map_offload_map_free, .map_check_btf = map_check_no_btf, + .map_mem_usage = bpf_map_offload_map_mem_usage, }; -static struct bpf_map *find_and_alloc_map(union bpf_attr *attr) +static void bpf_map_write_active_inc(struct bpf_map *map) { - const struct bpf_map_ops *ops; - u32 type = attr->map_type; - struct bpf_map *map; - int err; + atomic64_inc(&map->writecnt); +} - if (type >= ARRAY_SIZE(bpf_map_types)) - return ERR_PTR(-EINVAL); - type = array_index_nospec(type, ARRAY_SIZE(bpf_map_types)); - ops = bpf_map_types[type]; - if (!ops) - return ERR_PTR(-EINVAL); +static void bpf_map_write_active_dec(struct bpf_map *map) +{ + atomic64_dec(&map->writecnt); +} - if (ops->map_alloc_check) { - err = ops->map_alloc_check(attr); - if (err) - return ERR_PTR(err); - } - if (attr->map_ifindex) - ops = &bpf_map_offload_ops; - map = ops->map_alloc(attr); - if (IS_ERR(map)) - return map; - map->ops = ops; - map->map_type = type; - return map; +bool bpf_map_write_active(const struct bpf_map *map) +{ + return atomic64_read(&map->writecnt) != 0; } -void *bpf_map_area_alloc(size_t size, int numa_node) +static u32 bpf_map_value_size(const struct bpf_map *map) { - /* We definitely need __GFP_NORETRY, so OOM killer doesn't - * trigger under memory pressure as we really just want to - * fail instead. - */ - const gfp_t flags = __GFP_NOWARN | __GFP_NORETRY | __GFP_ZERO; - void *area; + if (map->map_type == BPF_MAP_TYPE_PERCPU_HASH || + map->map_type == BPF_MAP_TYPE_LRU_PERCPU_HASH || + map->map_type == BPF_MAP_TYPE_PERCPU_ARRAY || + map->map_type == BPF_MAP_TYPE_PERCPU_CGROUP_STORAGE) + return round_up(map->value_size, 8) * num_possible_cpus(); + else if (IS_FD_MAP(map)) + return sizeof(u32); + else + return map->value_size; +} - if (size <= (PAGE_SIZE << PAGE_ALLOC_COSTLY_ORDER)) { - area = kmalloc_node(size, GFP_USER | flags, numa_node); - if (area != NULL) - return area; - } +static void maybe_wait_bpf_programs(struct bpf_map *map) +{ + /* Wait for any running non-sleepable BPF programs to complete so that + * userspace, when we return to it, knows that all non-sleepable + * programs that could be running use the new map value. For sleepable + * BPF programs, synchronize_rcu_tasks_trace() should be used to wait + * for the completions of these programs, but considering the waiting + * time can be very long and userspace may think it will hang forever, + * so don't handle sleepable BPF programs now. + */ + if (map->map_type == BPF_MAP_TYPE_HASH_OF_MAPS || + map->map_type == BPF_MAP_TYPE_ARRAY_OF_MAPS) + synchronize_rcu_expedited(); +} - return __vmalloc_node_flags_caller(size, numa_node, GFP_KERNEL | flags, - __builtin_return_address(0)); +static void unpin_uptr_kaddr(void *kaddr) +{ + if (kaddr) + unpin_user_page(virt_to_page(kaddr)); } -void bpf_map_area_free(void *area) +static void __bpf_obj_unpin_uptrs(struct btf_record *rec, u32 cnt, void *obj) { - kvfree(area); + const struct btf_field *field; + void **uptr_addr; + int i; + + for (i = 0, field = rec->fields; i < cnt; i++, field++) { + if (field->type != BPF_UPTR) + continue; + + uptr_addr = obj + field->offset; + unpin_uptr_kaddr(*uptr_addr); + } } -void bpf_map_init_from_attr(struct bpf_map *map, union bpf_attr *attr) +static void bpf_obj_unpin_uptrs(struct btf_record *rec, void *obj) { - map->map_type = attr->map_type; - map->key_size = attr->key_size; - map->value_size = attr->value_size; - map->max_entries = attr->max_entries; - map->map_flags = attr->map_flags; - map->numa_node = bpf_map_attr_numa_node(attr); + if (!btf_record_has_field(rec, BPF_UPTR)) + return; + + __bpf_obj_unpin_uptrs(rec, rec->cnt, obj); } -int bpf_map_precharge_memlock(u32 pages) +static int bpf_obj_pin_uptrs(struct btf_record *rec, void *obj) { - struct user_struct *user = get_current_user(); - unsigned long memlock_limit, cur; + const struct btf_field *field; + const struct btf_type *t; + unsigned long start, end; + struct page *page; + void **uptr_addr; + int i, err; + + if (!btf_record_has_field(rec, BPF_UPTR)) + return 0; + + for (i = 0, field = rec->fields; i < rec->cnt; i++, field++) { + if (field->type != BPF_UPTR) + continue; + + uptr_addr = obj + field->offset; + start = *(unsigned long *)uptr_addr; + if (!start) + continue; + + t = btf_type_by_id(field->kptr.btf, field->kptr.btf_id); + /* t->size was checked for zero before */ + if (check_add_overflow(start, t->size - 1, &end)) { + err = -EFAULT; + goto unpin_all; + } + + /* The uptr's struct cannot span across two pages */ + if ((start & PAGE_MASK) != (end & PAGE_MASK)) { + err = -EOPNOTSUPP; + goto unpin_all; + } + + err = pin_user_pages_fast(start, 1, FOLL_LONGTERM | FOLL_WRITE, &page); + if (err != 1) + goto unpin_all; + + if (PageHighMem(page)) { + err = -EOPNOTSUPP; + unpin_user_page(page); + goto unpin_all; + } + + *uptr_addr = page_address(page) + offset_in_page(start); + } - memlock_limit = rlimit(RLIMIT_MEMLOCK) >> PAGE_SHIFT; - cur = atomic_long_read(&user->locked_vm); - free_uid(user); - if (cur + pages > memlock_limit) - return -EPERM; return 0; + +unpin_all: + __bpf_obj_unpin_uptrs(rec, i, obj); + return err; } -static int bpf_charge_memlock(struct user_struct *user, u32 pages) +static int bpf_map_update_value(struct bpf_map *map, struct file *map_file, + void *key, void *value, __u64 flags) { - unsigned long memlock_limit = rlimit(RLIMIT_MEMLOCK) >> PAGE_SHIFT; + int err; - if (atomic_long_add_return(pages, &user->locked_vm) > memlock_limit) { - atomic_long_sub(pages, &user->locked_vm); - return -EPERM; + /* Need to create a kthread, thus must support schedule */ + if (bpf_map_is_offloaded(map)) { + return bpf_map_offload_update_elem(map, key, value, flags); + } else if (map->map_type == BPF_MAP_TYPE_CPUMAP || + map->map_type == BPF_MAP_TYPE_ARENA || + map->map_type == BPF_MAP_TYPE_STRUCT_OPS) { + return map->ops->map_update_elem(map, key, value, flags); + } else if (map->map_type == BPF_MAP_TYPE_SOCKHASH || + map->map_type == BPF_MAP_TYPE_SOCKMAP) { + return sock_map_update_elem_sys(map, key, value, flags); + } else if (IS_FD_PROG_ARRAY(map)) { + return bpf_fd_array_map_update_elem(map, map_file, key, value, + flags); } - return 0; + + bpf_disable_instrumentation(); + if (map->map_type == BPF_MAP_TYPE_PERCPU_HASH || + map->map_type == BPF_MAP_TYPE_LRU_PERCPU_HASH) { + err = bpf_percpu_hash_update(map, key, value, flags); + } else if (map->map_type == BPF_MAP_TYPE_PERCPU_ARRAY) { + err = bpf_percpu_array_update(map, key, value, flags); + } else if (map->map_type == BPF_MAP_TYPE_PERCPU_CGROUP_STORAGE) { + err = bpf_percpu_cgroup_storage_update(map, key, value, + flags); + } else if (IS_FD_ARRAY(map)) { + err = bpf_fd_array_map_update_elem(map, map_file, key, value, + flags); + } else if (map->map_type == BPF_MAP_TYPE_HASH_OF_MAPS) { + err = bpf_fd_htab_map_update_elem(map, map_file, key, value, + flags); + } else if (map->map_type == BPF_MAP_TYPE_REUSEPORT_SOCKARRAY) { + /* rcu_read_lock() is not needed */ + err = bpf_fd_reuseport_array_update_elem(map, key, value, + flags); + } else if (map->map_type == BPF_MAP_TYPE_QUEUE || + map->map_type == BPF_MAP_TYPE_STACK || + map->map_type == BPF_MAP_TYPE_BLOOM_FILTER) { + err = map->ops->map_push_elem(map, value, flags); + } else { + err = bpf_obj_pin_uptrs(map->record, value); + if (!err) { + rcu_read_lock(); + err = map->ops->map_update_elem(map, key, value, flags); + rcu_read_unlock(); + if (err) + bpf_obj_unpin_uptrs(map->record, value); + } + } + bpf_enable_instrumentation(); + + return err; } -static void bpf_uncharge_memlock(struct user_struct *user, u32 pages) +static int bpf_map_copy_value(struct bpf_map *map, void *key, void *value, + __u64 flags) { - atomic_long_sub(pages, &user->locked_vm); + void *ptr; + int err; + + if (bpf_map_is_offloaded(map)) + return bpf_map_offload_lookup_elem(map, key, value); + + bpf_disable_instrumentation(); + if (map->map_type == BPF_MAP_TYPE_PERCPU_HASH || + map->map_type == BPF_MAP_TYPE_LRU_PERCPU_HASH) { + err = bpf_percpu_hash_copy(map, key, value); + } else if (map->map_type == BPF_MAP_TYPE_PERCPU_ARRAY) { + err = bpf_percpu_array_copy(map, key, value); + } else if (map->map_type == BPF_MAP_TYPE_PERCPU_CGROUP_STORAGE) { + err = bpf_percpu_cgroup_storage_copy(map, key, value); + } else if (map->map_type == BPF_MAP_TYPE_STACK_TRACE) { + err = bpf_stackmap_extract(map, key, value, false); + } else if (IS_FD_ARRAY(map) || IS_FD_PROG_ARRAY(map)) { + err = bpf_fd_array_map_lookup_elem(map, key, value); + } else if (IS_FD_HASH(map)) { + err = bpf_fd_htab_map_lookup_elem(map, key, value); + } else if (map->map_type == BPF_MAP_TYPE_REUSEPORT_SOCKARRAY) { + err = bpf_fd_reuseport_array_lookup_elem(map, key, value); + } else if (map->map_type == BPF_MAP_TYPE_QUEUE || + map->map_type == BPF_MAP_TYPE_STACK || + map->map_type == BPF_MAP_TYPE_BLOOM_FILTER) { + err = map->ops->map_peek_elem(map, value); + } else if (map->map_type == BPF_MAP_TYPE_STRUCT_OPS) { + /* struct_ops map requires directly updating "value" */ + err = bpf_struct_ops_map_sys_lookup_elem(map, key, value); + } else { + rcu_read_lock(); + if (map->ops->map_lookup_elem_sys_only) + ptr = map->ops->map_lookup_elem_sys_only(map, key); + else + ptr = map->ops->map_lookup_elem(map, key); + if (IS_ERR(ptr)) { + err = PTR_ERR(ptr); + } else if (!ptr) { + err = -ENOENT; + } else { + err = 0; + if (flags & BPF_F_LOCK) + /* lock 'ptr' and copy everything but lock */ + copy_map_value_locked(map, value, ptr, true); + else + copy_map_value(map, value, ptr); + /* mask lock and timer, since value wasn't zero inited */ + check_and_init_map_value(map, value); + } + rcu_read_unlock(); + } + + bpf_enable_instrumentation(); + + return err; } -static int bpf_map_init_memlock(struct bpf_map *map) +/* Please, do not use this function outside from the map creation path + * (e.g. in map update path) without taking care of setting the active + * memory cgroup (see at bpf_map_kmalloc_node() for example). + */ +static void *__bpf_map_area_alloc(u64 size, int numa_node, bool mmapable) { - struct user_struct *user = get_current_user(); - int ret; + /* We really just want to fail instead of triggering OOM killer + * under memory pressure, therefore we set __GFP_NORETRY to kmalloc, + * which is used for lower order allocation requests. + * + * It has been observed that higher order allocation requests done by + * vmalloc with __GFP_NORETRY being set might fail due to not trying + * to reclaim memory from the page cache, thus we set + * __GFP_RETRY_MAYFAIL to avoid such situations. + */ - ret = bpf_charge_memlock(user, map->pages); - if (ret) { - free_uid(user); - return ret; + gfp_t gfp = bpf_memcg_flags(__GFP_NOWARN | __GFP_ZERO); + unsigned int flags = 0; + unsigned long align = 1; + void *area; + + if (size >= SIZE_MAX) + return NULL; + + /* kmalloc()'ed memory can't be mmap()'ed */ + if (mmapable) { + BUG_ON(!PAGE_ALIGNED(size)); + align = SHMLBA; + flags = VM_USERMAP; + } else if (size <= (PAGE_SIZE << PAGE_ALLOC_COSTLY_ORDER)) { + area = kmalloc_node(size, gfp | GFP_USER | __GFP_NORETRY, + numa_node); + if (area != NULL) + return area; } - map->user = user; - return ret; + + return __vmalloc_node_range(size, align, VMALLOC_START, VMALLOC_END, + gfp | GFP_KERNEL | __GFP_RETRY_MAYFAIL, PAGE_KERNEL, + flags, numa_node, __builtin_return_address(0)); } -static void bpf_map_release_memlock(struct bpf_map *map) +void *bpf_map_area_alloc(u64 size, int numa_node) { - struct user_struct *user = map->user; - bpf_uncharge_memlock(user, map->pages); - free_uid(user); + return __bpf_map_area_alloc(size, numa_node, false); } -int bpf_map_charge_memlock(struct bpf_map *map, u32 pages) +void *bpf_map_area_mmapable_alloc(u64 size, int numa_node) { - int ret; + return __bpf_map_area_alloc(size, numa_node, true); +} - ret = bpf_charge_memlock(map->user, pages); - if (ret) - return ret; - map->pages += pages; - return ret; +void bpf_map_area_free(void *area) +{ + kvfree(area); +} + +static u32 bpf_map_flags_retain_permanent(u32 flags) +{ + /* Some map creation flags are not tied to the map object but + * rather to the map fd instead, so they have no meaning upon + * map object inspection since multiple file descriptors with + * different (access) properties can exist here. Thus, given + * this has zero meaning for the map itself, lets clear these + * from here. + */ + return flags & ~(BPF_F_RDONLY | BPF_F_WRONLY); } -void bpf_map_uncharge_memlock(struct bpf_map *map, u32 pages) +void bpf_map_init_from_attr(struct bpf_map *map, union bpf_attr *attr) { - bpf_uncharge_memlock(map->user, pages); - map->pages -= pages; + map->map_type = attr->map_type; + map->key_size = attr->key_size; + map->value_size = attr->value_size; + map->max_entries = attr->max_entries; + map->map_flags = bpf_map_flags_retain_permanent(attr->map_flags); + map->numa_node = bpf_map_attr_numa_node(attr); + map->map_extra = attr->map_extra; } static int bpf_map_alloc_id(struct bpf_map *map) @@ -253,7 +459,7 @@ static int bpf_map_alloc_id(struct bpf_map *map) return id > 0 ? 0 : id; } -void bpf_map_free_id(struct bpf_map *map, bool do_idr_lock) +void bpf_map_free_id(struct bpf_map *map) { unsigned long flags; @@ -265,18 +471,443 @@ void bpf_map_free_id(struct bpf_map *map, bool do_idr_lock) if (!map->id) return; - if (do_idr_lock) - spin_lock_irqsave(&map_idr_lock, flags); - else - __acquire(&map_idr_lock); + spin_lock_irqsave(&map_idr_lock, flags); idr_remove(&map_idr, map->id); map->id = 0; - if (do_idr_lock) - spin_unlock_irqrestore(&map_idr_lock, flags); - else - __release(&map_idr_lock); + spin_unlock_irqrestore(&map_idr_lock, flags); +} + +#ifdef CONFIG_MEMCG +static void bpf_map_save_memcg(struct bpf_map *map) +{ + /* Currently if a map is created by a process belonging to the root + * memory cgroup, get_obj_cgroup_from_current() will return NULL. + * So we have to check map->objcg for being NULL each time it's + * being used. + */ + if (memcg_bpf_enabled()) + map->objcg = get_obj_cgroup_from_current(); +} + +static void bpf_map_release_memcg(struct bpf_map *map) +{ + if (map->objcg) + obj_cgroup_put(map->objcg); +} + +static struct mem_cgroup *bpf_map_get_memcg(const struct bpf_map *map) +{ + if (map->objcg) + return get_mem_cgroup_from_objcg(map->objcg); + + return root_mem_cgroup; +} + +void *bpf_map_kmalloc_node(const struct bpf_map *map, size_t size, gfp_t flags, + int node) +{ + struct mem_cgroup *memcg, *old_memcg; + void *ptr; + + memcg = bpf_map_get_memcg(map); + old_memcg = set_active_memcg(memcg); + ptr = kmalloc_node(size, flags | __GFP_ACCOUNT, node); + set_active_memcg(old_memcg); + mem_cgroup_put(memcg); + + return ptr; +} + +void *bpf_map_kmalloc_nolock(const struct bpf_map *map, size_t size, gfp_t flags, + int node) +{ + struct mem_cgroup *memcg, *old_memcg; + void *ptr; + + memcg = bpf_map_get_memcg(map); + old_memcg = set_active_memcg(memcg); + ptr = kmalloc_nolock(size, flags | __GFP_ACCOUNT, node); + set_active_memcg(old_memcg); + mem_cgroup_put(memcg); + + return ptr; +} + +void *bpf_map_kzalloc(const struct bpf_map *map, size_t size, gfp_t flags) +{ + struct mem_cgroup *memcg, *old_memcg; + void *ptr; + + memcg = bpf_map_get_memcg(map); + old_memcg = set_active_memcg(memcg); + ptr = kzalloc(size, flags | __GFP_ACCOUNT); + set_active_memcg(old_memcg); + mem_cgroup_put(memcg); + + return ptr; +} + +void *bpf_map_kvcalloc(struct bpf_map *map, size_t n, size_t size, + gfp_t flags) +{ + struct mem_cgroup *memcg, *old_memcg; + void *ptr; + + memcg = bpf_map_get_memcg(map); + old_memcg = set_active_memcg(memcg); + ptr = kvcalloc(n, size, flags | __GFP_ACCOUNT); + set_active_memcg(old_memcg); + mem_cgroup_put(memcg); + + return ptr; +} + +void __percpu *bpf_map_alloc_percpu(const struct bpf_map *map, size_t size, + size_t align, gfp_t flags) +{ + struct mem_cgroup *memcg, *old_memcg; + void __percpu *ptr; + + memcg = bpf_map_get_memcg(map); + old_memcg = set_active_memcg(memcg); + ptr = __alloc_percpu_gfp(size, align, flags | __GFP_ACCOUNT); + set_active_memcg(old_memcg); + mem_cgroup_put(memcg); + + return ptr; +} + +#else +static void bpf_map_save_memcg(struct bpf_map *map) +{ +} + +static void bpf_map_release_memcg(struct bpf_map *map) +{ +} +#endif + +static bool can_alloc_pages(void) +{ + return preempt_count() == 0 && !irqs_disabled() && + !IS_ENABLED(CONFIG_PREEMPT_RT); +} + +static struct page *__bpf_alloc_page(int nid) +{ + if (!can_alloc_pages()) + return alloc_pages_nolock(__GFP_ACCOUNT, nid, 0); + + return alloc_pages_node(nid, + GFP_KERNEL | __GFP_ZERO | __GFP_ACCOUNT + | __GFP_NOWARN, + 0); +} + +int bpf_map_alloc_pages(const struct bpf_map *map, int nid, + unsigned long nr_pages, struct page **pages) +{ + unsigned long i, j; + struct page *pg; + int ret = 0; +#ifdef CONFIG_MEMCG + struct mem_cgroup *memcg, *old_memcg; + + memcg = bpf_map_get_memcg(map); + old_memcg = set_active_memcg(memcg); +#endif + for (i = 0; i < nr_pages; i++) { + pg = __bpf_alloc_page(nid); + + if (pg) { + pages[i] = pg; + continue; + } + for (j = 0; j < i; j++) + free_pages_nolock(pages[j], 0); + ret = -ENOMEM; + break; + } + +#ifdef CONFIG_MEMCG + set_active_memcg(old_memcg); + mem_cgroup_put(memcg); +#endif + return ret; +} + + +static int btf_field_cmp(const void *a, const void *b) +{ + const struct btf_field *f1 = a, *f2 = b; + + if (f1->offset < f2->offset) + return -1; + else if (f1->offset > f2->offset) + return 1; + return 0; +} + +struct btf_field *btf_record_find(const struct btf_record *rec, u32 offset, + u32 field_mask) +{ + struct btf_field *field; + + if (IS_ERR_OR_NULL(rec) || !(rec->field_mask & field_mask)) + return NULL; + field = bsearch(&offset, rec->fields, rec->cnt, sizeof(rec->fields[0]), btf_field_cmp); + if (!field || !(field->type & field_mask)) + return NULL; + return field; +} + +void btf_record_free(struct btf_record *rec) +{ + int i; + + if (IS_ERR_OR_NULL(rec)) + return; + for (i = 0; i < rec->cnt; i++) { + switch (rec->fields[i].type) { + case BPF_KPTR_UNREF: + case BPF_KPTR_REF: + case BPF_KPTR_PERCPU: + case BPF_UPTR: + if (rec->fields[i].kptr.module) + module_put(rec->fields[i].kptr.module); + if (btf_is_kernel(rec->fields[i].kptr.btf)) + btf_put(rec->fields[i].kptr.btf); + break; + case BPF_LIST_HEAD: + case BPF_LIST_NODE: + case BPF_RB_ROOT: + case BPF_RB_NODE: + case BPF_SPIN_LOCK: + case BPF_RES_SPIN_LOCK: + case BPF_TIMER: + case BPF_REFCOUNT: + case BPF_WORKQUEUE: + case BPF_TASK_WORK: + /* Nothing to release */ + break; + default: + WARN_ON_ONCE(1); + continue; + } + } + kfree(rec); +} + +void bpf_map_free_record(struct bpf_map *map) +{ + btf_record_free(map->record); + map->record = NULL; +} + +struct btf_record *btf_record_dup(const struct btf_record *rec) +{ + const struct btf_field *fields; + struct btf_record *new_rec; + int ret, size, i; + + if (IS_ERR_OR_NULL(rec)) + return NULL; + size = struct_size(rec, fields, rec->cnt); + new_rec = kmemdup(rec, size, GFP_KERNEL | __GFP_NOWARN); + if (!new_rec) + return ERR_PTR(-ENOMEM); + /* Do a deep copy of the btf_record */ + fields = rec->fields; + new_rec->cnt = 0; + for (i = 0; i < rec->cnt; i++) { + switch (fields[i].type) { + case BPF_KPTR_UNREF: + case BPF_KPTR_REF: + case BPF_KPTR_PERCPU: + case BPF_UPTR: + if (btf_is_kernel(fields[i].kptr.btf)) + btf_get(fields[i].kptr.btf); + if (fields[i].kptr.module && !try_module_get(fields[i].kptr.module)) { + ret = -ENXIO; + goto free; + } + break; + case BPF_LIST_HEAD: + case BPF_LIST_NODE: + case BPF_RB_ROOT: + case BPF_RB_NODE: + case BPF_SPIN_LOCK: + case BPF_RES_SPIN_LOCK: + case BPF_TIMER: + case BPF_REFCOUNT: + case BPF_WORKQUEUE: + case BPF_TASK_WORK: + /* Nothing to acquire */ + break; + default: + ret = -EFAULT; + WARN_ON_ONCE(1); + goto free; + } + new_rec->cnt++; + } + return new_rec; +free: + btf_record_free(new_rec); + return ERR_PTR(ret); +} + +bool btf_record_equal(const struct btf_record *rec_a, const struct btf_record *rec_b) +{ + bool a_has_fields = !IS_ERR_OR_NULL(rec_a), b_has_fields = !IS_ERR_OR_NULL(rec_b); + int size; + + if (!a_has_fields && !b_has_fields) + return true; + if (a_has_fields != b_has_fields) + return false; + if (rec_a->cnt != rec_b->cnt) + return false; + size = struct_size(rec_a, fields, rec_a->cnt); + /* btf_parse_fields uses kzalloc to allocate a btf_record, so unused + * members are zeroed out. So memcmp is safe to do without worrying + * about padding/unused fields. + * + * While spin_lock, timer, and kptr have no relation to map BTF, + * list_head metadata is specific to map BTF, the btf and value_rec + * members in particular. btf is the map BTF, while value_rec points to + * btf_record in that map BTF. + * + * So while by default, we don't rely on the map BTF (which the records + * were parsed from) matching for both records, which is not backwards + * compatible, in case list_head is part of it, we implicitly rely on + * that by way of depending on memcmp succeeding for it. + */ + return !memcmp(rec_a, rec_b, size); +} + +void bpf_obj_free_timer(const struct btf_record *rec, void *obj) +{ + if (WARN_ON_ONCE(!btf_record_has_field(rec, BPF_TIMER))) + return; + bpf_timer_cancel_and_free(obj + rec->timer_off); +} + +void bpf_obj_free_workqueue(const struct btf_record *rec, void *obj) +{ + if (WARN_ON_ONCE(!btf_record_has_field(rec, BPF_WORKQUEUE))) + return; + bpf_wq_cancel_and_free(obj + rec->wq_off); +} + +void bpf_obj_free_task_work(const struct btf_record *rec, void *obj) +{ + if (WARN_ON_ONCE(!btf_record_has_field(rec, BPF_TASK_WORK))) + return; + bpf_task_work_cancel_and_free(obj + rec->task_work_off); +} + +void bpf_obj_free_fields(const struct btf_record *rec, void *obj) +{ + const struct btf_field *fields; + int i; + + if (IS_ERR_OR_NULL(rec)) + return; + fields = rec->fields; + for (i = 0; i < rec->cnt; i++) { + struct btf_struct_meta *pointee_struct_meta; + const struct btf_field *field = &fields[i]; + void *field_ptr = obj + field->offset; + void *xchgd_field; + + switch (fields[i].type) { + case BPF_SPIN_LOCK: + case BPF_RES_SPIN_LOCK: + break; + case BPF_TIMER: + bpf_timer_cancel_and_free(field_ptr); + break; + case BPF_WORKQUEUE: + bpf_wq_cancel_and_free(field_ptr); + break; + case BPF_TASK_WORK: + bpf_task_work_cancel_and_free(field_ptr); + break; + case BPF_KPTR_UNREF: + WRITE_ONCE(*(u64 *)field_ptr, 0); + break; + case BPF_KPTR_REF: + case BPF_KPTR_PERCPU: + xchgd_field = (void *)xchg((unsigned long *)field_ptr, 0); + if (!xchgd_field) + break; + + if (!btf_is_kernel(field->kptr.btf)) { + pointee_struct_meta = btf_find_struct_meta(field->kptr.btf, + field->kptr.btf_id); + __bpf_obj_drop_impl(xchgd_field, pointee_struct_meta ? + pointee_struct_meta->record : NULL, + fields[i].type == BPF_KPTR_PERCPU); + } else { + field->kptr.dtor(xchgd_field); + } + break; + case BPF_UPTR: + /* The caller ensured that no one is using the uptr */ + unpin_uptr_kaddr(*(void **)field_ptr); + break; + case BPF_LIST_HEAD: + if (WARN_ON_ONCE(rec->spin_lock_off < 0)) + continue; + bpf_list_head_free(field, field_ptr, obj + rec->spin_lock_off); + break; + case BPF_RB_ROOT: + if (WARN_ON_ONCE(rec->spin_lock_off < 0)) + continue; + bpf_rb_root_free(field, field_ptr, obj + rec->spin_lock_off); + break; + case BPF_LIST_NODE: + case BPF_RB_NODE: + case BPF_REFCOUNT: + break; + default: + WARN_ON_ONCE(1); + continue; + } + } +} + +static void bpf_map_free(struct bpf_map *map) +{ + struct btf_record *rec = map->record; + struct btf *btf = map->btf; + + /* implementation dependent freeing. Disabling migration to simplify + * the free of values or special fields allocated from bpf memory + * allocator. + */ + kfree(map->excl_prog_sha); + migrate_disable(); + map->ops->map_free(map); + migrate_enable(); + + /* Delay freeing of btf_record for maps, as map_free + * callback usually needs access to them. It is better to do it here + * than require each callback to do the free itself manually. + * + * Note that the btf_record stashed in map->inner_map_meta->record was + * already freed using the map_free callback for map in map case which + * eventually calls bpf_map_free_meta, since inner_map_meta is only a + * template bpf_map struct used during verification. + */ + btf_record_free(rec); + /* Delay freeing of btf for maps, as map_free callback may need + * struct_meta info which will be freed with btf_put(). + */ + btf_put(btf); } /* called from workqueue */ @@ -284,37 +915,59 @@ static void bpf_map_free_deferred(struct work_struct *work) { struct bpf_map *map = container_of(work, struct bpf_map, work); - bpf_map_release_memlock(map); security_bpf_map_free(map); - /* implementation dependent freeing */ - map->ops->map_free(map); + bpf_map_release_memcg(map); + bpf_map_owner_free(map); + bpf_map_free(map); } static void bpf_map_put_uref(struct bpf_map *map) { - if (atomic_dec_and_test(&map->usercnt)) { + if (atomic64_dec_and_test(&map->usercnt)) { if (map->ops->map_release_uref) map->ops->map_release_uref(map); } } -/* decrement map refcnt and schedule it for freeing via workqueue - * (unrelying map implementation ops->map_free() might sleep) - */ -static void __bpf_map_put(struct bpf_map *map, bool do_idr_lock) +static void bpf_map_free_in_work(struct bpf_map *map) { - if (atomic_dec_and_test(&map->refcnt)) { - /* bpf_map_free_id() must be called first */ - bpf_map_free_id(map, do_idr_lock); - btf_put(map->btf); - INIT_WORK(&map->work, bpf_map_free_deferred); - schedule_work(&map->work); - } + INIT_WORK(&map->work, bpf_map_free_deferred); + /* Avoid spawning kworkers, since they all might contend + * for the same mutex like slab_mutex. + */ + queue_work(system_dfl_wq, &map->work); +} + +static void bpf_map_free_rcu_gp(struct rcu_head *rcu) +{ + bpf_map_free_in_work(container_of(rcu, struct bpf_map, rcu)); +} + +static void bpf_map_free_mult_rcu_gp(struct rcu_head *rcu) +{ + if (rcu_trace_implies_rcu_gp()) + bpf_map_free_rcu_gp(rcu); + else + call_rcu(rcu, bpf_map_free_rcu_gp); } +/* decrement map refcnt and schedule it for freeing via workqueue + * (underlying map implementation ops->map_free() might sleep) + */ void bpf_map_put(struct bpf_map *map) { - __bpf_map_put(map, true); + if (atomic64_dec_and_test(&map->refcnt)) { + /* bpf_map_free_id() must be called first */ + bpf_map_free_id(map); + + WARN_ON_ONCE(atomic64_read(&map->sleepable_refcnt)); + if (READ_ONCE(map->free_after_mult_rcu_gp)) + call_rcu_tasks_trace(&map->rcu, bpf_map_free_mult_rcu_gp); + else if (READ_ONCE(map->free_after_rcu_gp)) + call_rcu(&map->rcu, bpf_map_free_rcu_gp); + else + bpf_map_free_in_work(map); + } } EXPORT_SYMBOL_GPL(bpf_map_put); @@ -335,19 +988,36 @@ static int bpf_map_release(struct inode *inode, struct file *filp) return 0; } +static fmode_t map_get_sys_perms(struct bpf_map *map, struct fd f) +{ + fmode_t mode = fd_file(f)->f_mode; + + /* Our file permissions may have been overridden by global + * map permissions facing syscall side. + */ + if (READ_ONCE(map->frozen)) + mode &= ~FMODE_CAN_WRITE; + return mode; +} + #ifdef CONFIG_PROC_FS +/* Show the memory usage of a bpf map */ +static u64 bpf_map_memory_usage(const struct bpf_map *map) +{ + return map->ops->map_mem_usage(map); +} + static void bpf_map_show_fdinfo(struct seq_file *m, struct file *filp) { - const struct bpf_map *map = filp->private_data; - const struct bpf_array *array; - u32 owner_prog_type = 0; - u32 owner_jited = 0; + struct bpf_map *map = filp->private_data; + u32 type = 0, jited = 0; - if (map->map_type == BPF_MAP_TYPE_PROG_ARRAY) { - array = container_of(map, struct bpf_array, map); - owner_prog_type = array->owner_prog_type; - owner_jited = array->owner_jited; + spin_lock(&map->owner_lock); + if (map->owner) { + type = map->owner->type; + jited = map->owner->jited; } + spin_unlock(&map->owner_lock); seq_printf(m, "map_type:\t%u\n" @@ -355,21 +1025,22 @@ static void bpf_map_show_fdinfo(struct seq_file *m, struct file *filp) "value_size:\t%u\n" "max_entries:\t%u\n" "map_flags:\t%#x\n" + "map_extra:\t%#llx\n" "memlock:\t%llu\n" - "map_id:\t%u\n", + "map_id:\t%u\n" + "frozen:\t%u\n", map->map_type, map->key_size, map->value_size, map->max_entries, map->map_flags, - map->pages * 1ULL << PAGE_SHIFT, - map->id); - - if (owner_prog_type) { - seq_printf(m, "owner_prog_type:\t%u\n", - owner_prog_type); - seq_printf(m, "owner_jited:\t%u\n", - owner_jited); + (unsigned long long)map->map_extra, + bpf_map_memory_usage(map), + map->id, + READ_ONCE(map->frozen)); + if (type) { + seq_printf(m, "owner_prog_type:\t%u\n", type); + seq_printf(m, "owner_jited:\t%u\n", jited); } } #endif @@ -392,6 +1063,111 @@ static ssize_t bpf_dummy_write(struct file *filp, const char __user *buf, return -EINVAL; } +/* called for any extra memory-mapped regions (except initial) */ +static void bpf_map_mmap_open(struct vm_area_struct *vma) +{ + struct bpf_map *map = vma->vm_file->private_data; + + if (vma->vm_flags & VM_MAYWRITE) + bpf_map_write_active_inc(map); +} + +/* called for all unmapped memory region (including initial) */ +static void bpf_map_mmap_close(struct vm_area_struct *vma) +{ + struct bpf_map *map = vma->vm_file->private_data; + + if (vma->vm_flags & VM_MAYWRITE) + bpf_map_write_active_dec(map); +} + +static const struct vm_operations_struct bpf_map_default_vmops = { + .open = bpf_map_mmap_open, + .close = bpf_map_mmap_close, +}; + +static int bpf_map_mmap(struct file *filp, struct vm_area_struct *vma) +{ + struct bpf_map *map = filp->private_data; + int err = 0; + + if (!map->ops->map_mmap || !IS_ERR_OR_NULL(map->record)) + return -ENOTSUPP; + + if (!(vma->vm_flags & VM_SHARED)) + return -EINVAL; + + mutex_lock(&map->freeze_mutex); + + if (vma->vm_flags & VM_WRITE) { + if (map->frozen) { + err = -EPERM; + goto out; + } + /* map is meant to be read-only, so do not allow mapping as + * writable, because it's possible to leak a writable page + * reference and allows user-space to still modify it after + * freezing, while verifier will assume contents do not change + */ + if (map->map_flags & BPF_F_RDONLY_PROG) { + err = -EACCES; + goto out; + } + bpf_map_write_active_inc(map); + } +out: + mutex_unlock(&map->freeze_mutex); + if (err) + return err; + + /* set default open/close callbacks */ + vma->vm_ops = &bpf_map_default_vmops; + vma->vm_private_data = map; + vm_flags_clear(vma, VM_MAYEXEC); + /* If mapping is read-only, then disallow potentially re-mapping with + * PROT_WRITE by dropping VM_MAYWRITE flag. This VM_MAYWRITE clearing + * means that as far as BPF map's memory-mapped VMAs are concerned, + * VM_WRITE and VM_MAYWRITE and equivalent, if one of them is set, + * both should be set, so we can forget about VM_MAYWRITE and always + * check just VM_WRITE + */ + if (!(vma->vm_flags & VM_WRITE)) + vm_flags_clear(vma, VM_MAYWRITE); + + err = map->ops->map_mmap(map, vma); + if (err) { + if (vma->vm_flags & VM_WRITE) + bpf_map_write_active_dec(map); + } + + return err; +} + +static __poll_t bpf_map_poll(struct file *filp, struct poll_table_struct *pts) +{ + struct bpf_map *map = filp->private_data; + + if (map->ops->map_poll) + return map->ops->map_poll(map, filp, pts); + + return EPOLLERR; +} + +static unsigned long bpf_get_unmapped_area(struct file *filp, unsigned long addr, + unsigned long len, unsigned long pgoff, + unsigned long flags) +{ + struct bpf_map *map = filp->private_data; + + if (map->ops->map_get_unmapped_area) + return map->ops->map_get_unmapped_area(filp, addr, len, pgoff, flags); +#ifdef CONFIG_MMU + return mm_get_unmapped_area(filp, addr, len, pgoff, flags); +#else + return addr; +#endif +} + const struct file_operations bpf_map_fops = { #ifdef CONFIG_PROC_FS .show_fdinfo = bpf_map_show_fdinfo, @@ -399,6 +1175,9 @@ const struct file_operations bpf_map_fops = { .release = bpf_map_release, .read = bpf_dummy_read, .write = bpf_dummy_write, + .mmap = bpf_map_mmap, + .poll = bpf_map_poll, + .get_unmapped_area = bpf_get_unmapped_area, }; int bpf_map_new_fd(struct bpf_map *map, int flags) @@ -432,28 +1211,30 @@ int bpf_get_file_flag(int flags) offsetof(union bpf_attr, CMD##_LAST_FIELD) - \ sizeof(attr->CMD##_LAST_FIELD)) != NULL -/* dst and src must have at least BPF_OBJ_NAME_LEN number of bytes. - * Return 0 on success and < 0 on error. +/* dst and src must have at least "size" number of bytes. + * Return strlen on success and < 0 on error. */ -static int bpf_obj_name_cpy(char *dst, const char *src) +int bpf_obj_name_cpy(char *dst, const char *src, unsigned int size) { - const char *end = src + BPF_OBJ_NAME_LEN; - - memset(dst, 0, BPF_OBJ_NAME_LEN); + const char *end = src + size; + const char *orig_src = src; - /* Copy all isalnum() and '_' char */ + memset(dst, 0, size); + /* Copy all isalnum(), '_' and '.' chars. */ while (src < end && *src) { - if (!isalnum(*src) && *src != '_') + if (!isalnum(*src) && + *src != '_' && *src != '.') return -EINVAL; *dst++ = *src++; } - /* No '\0' found in BPF_OBJ_NAME_LEN number of bytes */ + /* No '\0' found in "size" number of bytes */ if (src == end) return -EINVAL; - return 0; + return src - orig_src; } +EXPORT_SYMBOL_GPL(bpf_obj_name_cpy); int map_check_no_btf(const struct bpf_map *map, const struct btf *btf, @@ -463,33 +1244,143 @@ int map_check_no_btf(const struct bpf_map *map, return -ENOTSUPP; } -static int map_check_btf(const struct bpf_map *map, const struct btf *btf, - u32 btf_key_id, u32 btf_value_id) +static int map_check_btf(struct bpf_map *map, struct bpf_token *token, + const struct btf *btf, u32 btf_key_id, u32 btf_value_id) { const struct btf_type *key_type, *value_type; u32 key_size, value_size; int ret = 0; - key_type = btf_type_id_size(btf, &btf_key_id, &key_size); - if (!key_type || key_size != map->key_size) - return -EINVAL; + /* Some maps allow key to be unspecified. */ + if (btf_key_id) { + key_type = btf_type_id_size(btf, &btf_key_id, &key_size); + if (!key_type || key_size != map->key_size) + return -EINVAL; + } else { + key_type = btf_type_by_id(btf, 0); + if (!map->ops->map_check_btf) + return -EINVAL; + } value_type = btf_type_id_size(btf, &btf_value_id, &value_size); if (!value_type || value_size != map->value_size) return -EINVAL; - if (map->ops->map_check_btf) + map->record = btf_parse_fields(btf, value_type, + BPF_SPIN_LOCK | BPF_RES_SPIN_LOCK | BPF_TIMER | BPF_KPTR | BPF_LIST_HEAD | + BPF_RB_ROOT | BPF_REFCOUNT | BPF_WORKQUEUE | BPF_UPTR | + BPF_TASK_WORK, + map->value_size); + if (!IS_ERR_OR_NULL(map->record)) { + int i; + + if (!bpf_token_capable(token, CAP_BPF)) { + ret = -EPERM; + goto free_map_tab; + } + if (map->map_flags & (BPF_F_RDONLY_PROG | BPF_F_WRONLY_PROG)) { + ret = -EACCES; + goto free_map_tab; + } + for (i = 0; i < sizeof(map->record->field_mask) * 8; i++) { + switch (map->record->field_mask & (1 << i)) { + case 0: + continue; + case BPF_SPIN_LOCK: + case BPF_RES_SPIN_LOCK: + if (map->map_type != BPF_MAP_TYPE_HASH && + map->map_type != BPF_MAP_TYPE_ARRAY && + map->map_type != BPF_MAP_TYPE_CGROUP_STORAGE && + map->map_type != BPF_MAP_TYPE_SK_STORAGE && + map->map_type != BPF_MAP_TYPE_INODE_STORAGE && + map->map_type != BPF_MAP_TYPE_TASK_STORAGE && + map->map_type != BPF_MAP_TYPE_CGRP_STORAGE) { + ret = -EOPNOTSUPP; + goto free_map_tab; + } + break; + case BPF_TIMER: + case BPF_WORKQUEUE: + case BPF_TASK_WORK: + if (map->map_type != BPF_MAP_TYPE_HASH && + map->map_type != BPF_MAP_TYPE_LRU_HASH && + map->map_type != BPF_MAP_TYPE_ARRAY) { + ret = -EOPNOTSUPP; + goto free_map_tab; + } + break; + case BPF_KPTR_UNREF: + case BPF_KPTR_REF: + case BPF_KPTR_PERCPU: + case BPF_REFCOUNT: + if (map->map_type != BPF_MAP_TYPE_HASH && + map->map_type != BPF_MAP_TYPE_PERCPU_HASH && + map->map_type != BPF_MAP_TYPE_LRU_HASH && + map->map_type != BPF_MAP_TYPE_LRU_PERCPU_HASH && + map->map_type != BPF_MAP_TYPE_ARRAY && + map->map_type != BPF_MAP_TYPE_PERCPU_ARRAY && + map->map_type != BPF_MAP_TYPE_SK_STORAGE && + map->map_type != BPF_MAP_TYPE_INODE_STORAGE && + map->map_type != BPF_MAP_TYPE_TASK_STORAGE && + map->map_type != BPF_MAP_TYPE_CGRP_STORAGE) { + ret = -EOPNOTSUPP; + goto free_map_tab; + } + break; + case BPF_UPTR: + if (map->map_type != BPF_MAP_TYPE_TASK_STORAGE) { + ret = -EOPNOTSUPP; + goto free_map_tab; + } + break; + case BPF_LIST_HEAD: + case BPF_RB_ROOT: + if (map->map_type != BPF_MAP_TYPE_HASH && + map->map_type != BPF_MAP_TYPE_LRU_HASH && + map->map_type != BPF_MAP_TYPE_ARRAY) { + ret = -EOPNOTSUPP; + goto free_map_tab; + } + break; + default: + /* Fail if map_type checks are missing for a field type */ + ret = -EOPNOTSUPP; + goto free_map_tab; + } + } + } + + ret = btf_check_and_fixup_fields(btf, map->record); + if (ret < 0) + goto free_map_tab; + + if (map->ops->map_check_btf) { ret = map->ops->map_check_btf(map, btf, key_type, value_type); + if (ret < 0) + goto free_map_tab; + } return ret; +free_map_tab: + bpf_map_free_record(map); + return ret; } -#define BPF_MAP_CREATE_LAST_FIELD btf_value_type_id +static bool bpf_net_capable(void) +{ + return capable(CAP_NET_ADMIN) || capable(CAP_SYS_ADMIN); +} + +#define BPF_MAP_CREATE_LAST_FIELD excl_prog_hash_size /* called via syscall */ -static int map_create(union bpf_attr *attr) +static int map_create(union bpf_attr *attr, bpfptr_t uattr) { + const struct bpf_map_ops *ops; + struct bpf_token *token = NULL; int numa_node = bpf_map_attr_numa_node(attr); + u32 map_type = attr->map_type; struct bpf_map *map; + bool token_flag; int f_flags; int err; @@ -497,6 +1388,25 @@ static int map_create(union bpf_attr *attr) if (err) return -EINVAL; + /* check BPF_F_TOKEN_FD flag, remember if it's set, and then clear it + * to avoid per-map type checks tripping on unknown flag + */ + token_flag = attr->map_flags & BPF_F_TOKEN_FD; + attr->map_flags &= ~BPF_F_TOKEN_FD; + + if (attr->btf_vmlinux_value_type_id) { + if (attr->map_type != BPF_MAP_TYPE_STRUCT_OPS || + attr->btf_key_type_id || attr->btf_value_type_id) + return -EINVAL; + } else if (attr->btf_key_type_id && !attr->btf_value_type_id) { + return -EINVAL; + } + + if (attr->map_type != BPF_MAP_TYPE_BLOOM_FILTER && + attr->map_type != BPF_MAP_TYPE_ARENA && + attr->map_extra != 0) + return -EINVAL; + f_flags = bpf_get_file_flag(attr->map_flags); if (f_flags < 0) return f_flags; @@ -507,147 +1417,275 @@ static int map_create(union bpf_attr *attr) return -EINVAL; /* find map type and init map: hashtable vs rbtree vs bloom vs ... */ - map = find_and_alloc_map(attr); - if (IS_ERR(map)) - return PTR_ERR(map); - - err = bpf_obj_name_cpy(map->name, attr->map_name); - if (err) - goto free_map_nouncharge; + map_type = attr->map_type; + if (map_type >= ARRAY_SIZE(bpf_map_types)) + return -EINVAL; + map_type = array_index_nospec(map_type, ARRAY_SIZE(bpf_map_types)); + ops = bpf_map_types[map_type]; + if (!ops) + return -EINVAL; - atomic_set(&map->refcnt, 1); - atomic_set(&map->usercnt, 1); + if (ops->map_alloc_check) { + err = ops->map_alloc_check(attr); + if (err) + return err; + } + if (attr->map_ifindex) + ops = &bpf_map_offload_ops; + if (!ops->map_mem_usage) + return -EINVAL; - if (attr->btf_key_type_id || attr->btf_value_type_id) { - struct btf *btf; + if (token_flag) { + token = bpf_token_get_from_fd(attr->map_token_fd); + if (IS_ERR(token)) + return PTR_ERR(token); - if (!attr->btf_key_type_id || !attr->btf_value_type_id) { - err = -EINVAL; - goto free_map_nouncharge; + /* if current token doesn't grant map creation permissions, + * then we can't use this token, so ignore it and rely on + * system-wide capabilities checks + */ + if (!bpf_token_allow_cmd(token, BPF_MAP_CREATE) || + !bpf_token_allow_map_type(token, attr->map_type)) { + bpf_token_put(token); + token = NULL; } + } + + err = -EPERM; + + /* Intent here is for unprivileged_bpf_disabled to block BPF map + * creation for unprivileged users; other actions depend + * on fd availability and access to bpffs, so are dependent on + * object creation success. Even with unprivileged BPF disabled, + * capability checks are still carried out. + */ + if (sysctl_unprivileged_bpf_disabled && !bpf_token_capable(token, CAP_BPF)) + goto put_token; + + /* check privileged map type permissions */ + switch (map_type) { + case BPF_MAP_TYPE_ARRAY: + case BPF_MAP_TYPE_PERCPU_ARRAY: + case BPF_MAP_TYPE_PROG_ARRAY: + case BPF_MAP_TYPE_PERF_EVENT_ARRAY: + case BPF_MAP_TYPE_CGROUP_ARRAY: + case BPF_MAP_TYPE_ARRAY_OF_MAPS: + case BPF_MAP_TYPE_HASH: + case BPF_MAP_TYPE_PERCPU_HASH: + case BPF_MAP_TYPE_HASH_OF_MAPS: + case BPF_MAP_TYPE_RINGBUF: + case BPF_MAP_TYPE_USER_RINGBUF: + case BPF_MAP_TYPE_CGROUP_STORAGE: + case BPF_MAP_TYPE_PERCPU_CGROUP_STORAGE: + /* unprivileged */ + break; + case BPF_MAP_TYPE_SK_STORAGE: + case BPF_MAP_TYPE_INODE_STORAGE: + case BPF_MAP_TYPE_TASK_STORAGE: + case BPF_MAP_TYPE_CGRP_STORAGE: + case BPF_MAP_TYPE_BLOOM_FILTER: + case BPF_MAP_TYPE_LPM_TRIE: + case BPF_MAP_TYPE_REUSEPORT_SOCKARRAY: + case BPF_MAP_TYPE_STACK_TRACE: + case BPF_MAP_TYPE_QUEUE: + case BPF_MAP_TYPE_STACK: + case BPF_MAP_TYPE_LRU_HASH: + case BPF_MAP_TYPE_LRU_PERCPU_HASH: + case BPF_MAP_TYPE_STRUCT_OPS: + case BPF_MAP_TYPE_CPUMAP: + case BPF_MAP_TYPE_ARENA: + case BPF_MAP_TYPE_INSN_ARRAY: + if (!bpf_token_capable(token, CAP_BPF)) + goto put_token; + break; + case BPF_MAP_TYPE_SOCKMAP: + case BPF_MAP_TYPE_SOCKHASH: + case BPF_MAP_TYPE_DEVMAP: + case BPF_MAP_TYPE_DEVMAP_HASH: + case BPF_MAP_TYPE_XSKMAP: + if (!bpf_token_capable(token, CAP_NET_ADMIN)) + goto put_token; + break; + default: + WARN(1, "unsupported map type %d", map_type); + goto put_token; + } + + map = ops->map_alloc(attr); + if (IS_ERR(map)) { + err = PTR_ERR(map); + goto put_token; + } + map->ops = ops; + map->map_type = map_type; + + err = bpf_obj_name_cpy(map->name, attr->map_name, + sizeof(attr->map_name)); + if (err < 0) + goto free_map; + + preempt_disable(); + map->cookie = gen_cookie_next(&bpf_map_cookie); + preempt_enable(); + + atomic64_set(&map->refcnt, 1); + atomic64_set(&map->usercnt, 1); + mutex_init(&map->freeze_mutex); + spin_lock_init(&map->owner_lock); + + if (attr->btf_key_type_id || attr->btf_value_type_id || + /* Even the map's value is a kernel's struct, + * the bpf_prog.o must have BTF to begin with + * to figure out the corresponding kernel's + * counter part. Thus, attr->btf_fd has + * to be valid also. + */ + attr->btf_vmlinux_value_type_id) { + struct btf *btf; btf = btf_get_by_fd(attr->btf_fd); if (IS_ERR(btf)) { err = PTR_ERR(btf); - goto free_map_nouncharge; + goto free_map; } - - err = map_check_btf(map, btf, attr->btf_key_type_id, - attr->btf_value_type_id); - if (err) { + if (btf_is_kernel(btf)) { btf_put(btf); - goto free_map_nouncharge; + err = -EACCES; + goto free_map; } - map->btf = btf; + + if (attr->btf_value_type_id) { + err = map_check_btf(map, token, btf, attr->btf_key_type_id, + attr->btf_value_type_id); + if (err) + goto free_map; + } + map->btf_key_type_id = attr->btf_key_type_id; map->btf_value_type_id = attr->btf_value_type_id; + map->btf_vmlinux_value_type_id = + attr->btf_vmlinux_value_type_id; } - err = security_bpf_map_alloc(map); - if (err) - goto free_map_nouncharge; + if (attr->excl_prog_hash) { + bpfptr_t uprog_hash = make_bpfptr(attr->excl_prog_hash, uattr.is_kernel); - err = bpf_map_init_memlock(map); + if (attr->excl_prog_hash_size != SHA256_DIGEST_SIZE) { + err = -EINVAL; + goto free_map; + } + + map->excl_prog_sha = kzalloc(SHA256_DIGEST_SIZE, GFP_KERNEL); + if (!map->excl_prog_sha) { + err = -ENOMEM; + goto free_map; + } + + if (copy_from_bpfptr(map->excl_prog_sha, uprog_hash, SHA256_DIGEST_SIZE)) { + err = -EFAULT; + goto free_map; + } + } else if (attr->excl_prog_hash_size) { + err = -EINVAL; + goto free_map; + } + + err = security_bpf_map_create(map, attr, token, uattr.is_kernel); if (err) goto free_map_sec; err = bpf_map_alloc_id(map); if (err) - goto free_map; + goto free_map_sec; + + bpf_map_save_memcg(map); + bpf_token_put(token); err = bpf_map_new_fd(map, f_flags); if (err < 0) { /* failed to allocate fd. - * bpf_map_put() is needed because the above + * bpf_map_put_with_uref() is needed because the above * bpf_map_alloc_id() has published the map * to the userspace and the userspace may * have refcnt-ed it through BPF_MAP_GET_FD_BY_ID. */ - bpf_map_put(map); + bpf_map_put_with_uref(map); return err; } return err; -free_map: - bpf_map_release_memlock(map); free_map_sec: security_bpf_map_free(map); -free_map_nouncharge: - btf_put(map->btf); - map->ops->map_free(map); +free_map: + bpf_map_free(map); +put_token: + bpf_token_put(token); return err; } -/* if error is returned, fd is released. - * On success caller should complete fd access with matching fdput() - */ -struct bpf_map *__bpf_map_get(struct fd f) +void bpf_map_inc(struct bpf_map *map) { - if (!f.file) - return ERR_PTR(-EBADF); - if (f.file->f_op != &bpf_map_fops) { - fdput(f); - return ERR_PTR(-EINVAL); - } - - return f.file->private_data; + atomic64_inc(&map->refcnt); } +EXPORT_SYMBOL_GPL(bpf_map_inc); -/* prog's and map's refcnt limit */ -#define BPF_MAX_REFCNT 32768 +void bpf_map_inc_with_uref(struct bpf_map *map) +{ + atomic64_inc(&map->refcnt); + atomic64_inc(&map->usercnt); +} +EXPORT_SYMBOL_GPL(bpf_map_inc_with_uref); -struct bpf_map *bpf_map_inc(struct bpf_map *map, bool uref) +struct bpf_map *bpf_map_get(u32 ufd) { - if (atomic_inc_return(&map->refcnt) > BPF_MAX_REFCNT) { - atomic_dec(&map->refcnt); - return ERR_PTR(-EBUSY); - } - if (uref) - atomic_inc(&map->usercnt); + CLASS(fd, f)(ufd); + struct bpf_map *map = __bpf_map_get(f); + + if (!IS_ERR(map)) + bpf_map_inc(map); + return map; } -EXPORT_SYMBOL_GPL(bpf_map_inc); +EXPORT_SYMBOL_NS(bpf_map_get, "BPF_INTERNAL"); struct bpf_map *bpf_map_get_with_uref(u32 ufd) { - struct fd f = fdget(ufd); - struct bpf_map *map; + CLASS(fd, f)(ufd); + struct bpf_map *map = __bpf_map_get(f); - map = __bpf_map_get(f); - if (IS_ERR(map)) - return map; - - map = bpf_map_inc(map, true); - fdput(f); + if (!IS_ERR(map)) + bpf_map_inc_with_uref(map); return map; } -/* map_idr_lock should have been held */ -static struct bpf_map *bpf_map_inc_not_zero(struct bpf_map *map, - bool uref) +/* map_idr_lock should have been held or the map should have been + * protected by rcu read lock. + */ +struct bpf_map *__bpf_map_inc_not_zero(struct bpf_map *map, bool uref) { int refold; - refold = atomic_fetch_add_unless(&map->refcnt, 1, 0); - - if (refold >= BPF_MAX_REFCNT) { - __bpf_map_put(map, false); - return ERR_PTR(-EBUSY); - } - + refold = atomic64_fetch_add_unless(&map->refcnt, 1, 0); if (!refold) return ERR_PTR(-ENOENT); - if (uref) - atomic_inc(&map->usercnt); + atomic64_inc(&map->usercnt); return map; } -int __weak bpf_stackmap_copy(struct bpf_map *map, void *key, void *value) +struct bpf_map *bpf_map_inc_not_zero(struct bpf_map *map) +{ + lockdep_assert(rcu_read_lock_held()); + return __bpf_map_inc_not_zero(map, false); +} +EXPORT_SYMBOL_GPL(bpf_map_inc_not_zero); + +int __weak bpf_stackmap_extract(struct bpf_map *map, void *key, void *value, + bool delete) { return -ENOTSUPP; } @@ -655,7 +1693,7 @@ int __weak bpf_stackmap_copy(struct bpf_map *map, void *key, void *value) static void *__bpf_copy_key(void __user *ukey, u64 key_size) { if (key_size) - return memdup_user(ukey, key_size); + return vmemdup_user(ukey, key_size); if (ukey) return ERR_PTR(-EINVAL); @@ -663,88 +1701,63 @@ static void *__bpf_copy_key(void __user *ukey, u64 key_size) return NULL; } +static void *___bpf_copy_key(bpfptr_t ukey, u64 key_size) +{ + if (key_size) + return kvmemdup_bpfptr(ukey, key_size); + + if (!bpfptr_is_null(ukey)) + return ERR_PTR(-EINVAL); + + return NULL; +} + /* last field in 'union bpf_attr' used by this command */ -#define BPF_MAP_LOOKUP_ELEM_LAST_FIELD value +#define BPF_MAP_LOOKUP_ELEM_LAST_FIELD flags static int map_lookup_elem(union bpf_attr *attr) { void __user *ukey = u64_to_user_ptr(attr->key); void __user *uvalue = u64_to_user_ptr(attr->value); - int ufd = attr->map_fd; struct bpf_map *map; - void *key, *value, *ptr; + void *key, *value; u32 value_size; - struct fd f; int err; if (CHECK_ATTR(BPF_MAP_LOOKUP_ELEM)) return -EINVAL; - f = fdget(ufd); + CLASS(fd, f)(attr->map_fd); map = __bpf_map_get(f); if (IS_ERR(map)) return PTR_ERR(map); + if (!(map_get_sys_perms(map, f) & FMODE_CAN_READ)) + return -EPERM; - if (!(f.file->f_mode & FMODE_CAN_READ)) { - err = -EPERM; - goto err_put; - } + err = bpf_map_check_op_flags(map, attr->flags, BPF_F_LOCK); + if (err) + return err; key = __bpf_copy_key(ukey, map->key_size); - if (IS_ERR(key)) { - err = PTR_ERR(key); - goto err_put; - } + if (IS_ERR(key)) + return PTR_ERR(key); - if (map->map_type == BPF_MAP_TYPE_PERCPU_HASH || - map->map_type == BPF_MAP_TYPE_LRU_PERCPU_HASH || - map->map_type == BPF_MAP_TYPE_PERCPU_ARRAY || - map->map_type == BPF_MAP_TYPE_PERCPU_CGROUP_STORAGE) - value_size = round_up(map->value_size, 8) * num_possible_cpus(); - else if (IS_FD_MAP(map)) - value_size = sizeof(u32); - else - value_size = map->value_size; + value_size = bpf_map_value_size(map); err = -ENOMEM; - value = kmalloc(value_size, GFP_USER | __GFP_NOWARN); + value = kvmalloc(value_size, GFP_USER | __GFP_NOWARN); if (!value) goto free_key; - if (bpf_map_is_dev_bound(map)) { - err = bpf_map_offload_lookup_elem(map, key, value); - } else if (map->map_type == BPF_MAP_TYPE_PERCPU_HASH || - map->map_type == BPF_MAP_TYPE_LRU_PERCPU_HASH) { - err = bpf_percpu_hash_copy(map, key, value); - } else if (map->map_type == BPF_MAP_TYPE_PERCPU_ARRAY) { - err = bpf_percpu_array_copy(map, key, value); - } else if (map->map_type == BPF_MAP_TYPE_PERCPU_CGROUP_STORAGE) { - err = bpf_percpu_cgroup_storage_copy(map, key, value); - } else if (map->map_type == BPF_MAP_TYPE_STACK_TRACE) { - err = bpf_stackmap_copy(map, key, value); - } else if (IS_FD_ARRAY(map)) { - err = bpf_fd_array_map_lookup_elem(map, key, value); - } else if (IS_FD_HASH(map)) { - err = bpf_fd_htab_map_lookup_elem(map, key, value); - } else if (map->map_type == BPF_MAP_TYPE_REUSEPORT_SOCKARRAY) { - err = bpf_fd_reuseport_array_lookup_elem(map, key, value); - } else if (map->map_type == BPF_MAP_TYPE_QUEUE || - map->map_type == BPF_MAP_TYPE_STACK) { - err = map->ops->map_peek_elem(map, value); - } else { - rcu_read_lock(); - ptr = map->ops->map_lookup_elem(map, key); - if (IS_ERR(ptr)) { - err = PTR_ERR(ptr); - } else if (!ptr) { - err = -ENOENT; - } else { - err = 0; - memcpy(value, ptr, value_size); - } - rcu_read_unlock(); + if (map->map_type == BPF_MAP_TYPE_BLOOM_FILTER) { + if (copy_from_user(value, uvalue, value_size)) + err = -EFAULT; + else + err = bpf_map_copy_value(map, key, value, attr->flags); + goto free_value; } + err = bpf_map_copy_value(map, key, value, attr->flags); if (err) goto free_value; @@ -755,180 +1768,115 @@ static int map_lookup_elem(union bpf_attr *attr) err = 0; free_value: - kfree(value); + kvfree(value); free_key: - kfree(key); -err_put: - fdput(f); + kvfree(key); return err; } -static void maybe_wait_bpf_programs(struct bpf_map *map) -{ - /* Wait for any running BPF programs to complete so that - * userspace, when we return to it, knows that all programs - * that could be running use the new map value. - */ - if (map->map_type == BPF_MAP_TYPE_HASH_OF_MAPS || - map->map_type == BPF_MAP_TYPE_ARRAY_OF_MAPS) - synchronize_rcu(); -} #define BPF_MAP_UPDATE_ELEM_LAST_FIELD flags -static int map_update_elem(union bpf_attr *attr) +static int map_update_elem(union bpf_attr *attr, bpfptr_t uattr) { - void __user *ukey = u64_to_user_ptr(attr->key); - void __user *uvalue = u64_to_user_ptr(attr->value); - int ufd = attr->map_fd; + bpfptr_t ukey = make_bpfptr(attr->key, uattr.is_kernel); + bpfptr_t uvalue = make_bpfptr(attr->value, uattr.is_kernel); struct bpf_map *map; void *key, *value; u32 value_size; - struct fd f; int err; if (CHECK_ATTR(BPF_MAP_UPDATE_ELEM)) return -EINVAL; - f = fdget(ufd); + CLASS(fd, f)(attr->map_fd); map = __bpf_map_get(f); if (IS_ERR(map)) return PTR_ERR(map); - - if (!(f.file->f_mode & FMODE_CAN_WRITE)) { + bpf_map_write_active_inc(map); + if (!(map_get_sys_perms(map, f) & FMODE_CAN_WRITE)) { err = -EPERM; goto err_put; } - key = __bpf_copy_key(ukey, map->key_size); + err = bpf_map_check_op_flags(map, attr->flags, ~0); + if (err) + goto err_put; + + key = ___bpf_copy_key(ukey, map->key_size); if (IS_ERR(key)) { err = PTR_ERR(key); goto err_put; } - if (map->map_type == BPF_MAP_TYPE_PERCPU_HASH || - map->map_type == BPF_MAP_TYPE_LRU_PERCPU_HASH || - map->map_type == BPF_MAP_TYPE_PERCPU_ARRAY || - map->map_type == BPF_MAP_TYPE_PERCPU_CGROUP_STORAGE) - value_size = round_up(map->value_size, 8) * num_possible_cpus(); - else - value_size = map->value_size; - - err = -ENOMEM; - value = kmalloc(value_size, GFP_USER | __GFP_NOWARN); - if (!value) + value_size = bpf_map_value_size(map); + value = kvmemdup_bpfptr(uvalue, value_size); + if (IS_ERR(value)) { + err = PTR_ERR(value); goto free_key; - - err = -EFAULT; - if (copy_from_user(value, uvalue, value_size) != 0) - goto free_value; - - /* Need to create a kthread, thus must support schedule */ - if (bpf_map_is_dev_bound(map)) { - err = bpf_map_offload_update_elem(map, key, value, attr->flags); - goto out; - } else if (map->map_type == BPF_MAP_TYPE_CPUMAP || - map->map_type == BPF_MAP_TYPE_SOCKHASH || - map->map_type == BPF_MAP_TYPE_SOCKMAP) { - err = map->ops->map_update_elem(map, key, value, attr->flags); - goto out; } - /* must increment bpf_prog_active to avoid kprobe+bpf triggering from - * inside bpf map update or delete otherwise deadlocks are possible - */ - preempt_disable(); - __this_cpu_inc(bpf_prog_active); - if (map->map_type == BPF_MAP_TYPE_PERCPU_HASH || - map->map_type == BPF_MAP_TYPE_LRU_PERCPU_HASH) { - err = bpf_percpu_hash_update(map, key, value, attr->flags); - } else if (map->map_type == BPF_MAP_TYPE_PERCPU_ARRAY) { - err = bpf_percpu_array_update(map, key, value, attr->flags); - } else if (map->map_type == BPF_MAP_TYPE_PERCPU_CGROUP_STORAGE) { - err = bpf_percpu_cgroup_storage_update(map, key, value, - attr->flags); - } else if (IS_FD_ARRAY(map)) { - rcu_read_lock(); - err = bpf_fd_array_map_update_elem(map, f.file, key, value, - attr->flags); - rcu_read_unlock(); - } else if (map->map_type == BPF_MAP_TYPE_HASH_OF_MAPS) { - rcu_read_lock(); - err = bpf_fd_htab_map_update_elem(map, f.file, key, value, - attr->flags); - rcu_read_unlock(); - } else if (map->map_type == BPF_MAP_TYPE_REUSEPORT_SOCKARRAY) { - /* rcu_read_lock() is not needed */ - err = bpf_fd_reuseport_array_update_elem(map, key, value, - attr->flags); - } else if (map->map_type == BPF_MAP_TYPE_QUEUE || - map->map_type == BPF_MAP_TYPE_STACK) { - err = map->ops->map_push_elem(map, value, attr->flags); - } else { - rcu_read_lock(); - err = map->ops->map_update_elem(map, key, value, attr->flags); - rcu_read_unlock(); - } - __this_cpu_dec(bpf_prog_active); - preempt_enable(); - maybe_wait_bpf_programs(map); -out: -free_value: - kfree(value); + err = bpf_map_update_value(map, fd_file(f), key, value, attr->flags); + if (!err) + maybe_wait_bpf_programs(map); + + kvfree(value); free_key: - kfree(key); + kvfree(key); err_put: - fdput(f); + bpf_map_write_active_dec(map); return err; } #define BPF_MAP_DELETE_ELEM_LAST_FIELD key -static int map_delete_elem(union bpf_attr *attr) +static int map_delete_elem(union bpf_attr *attr, bpfptr_t uattr) { - void __user *ukey = u64_to_user_ptr(attr->key); - int ufd = attr->map_fd; + bpfptr_t ukey = make_bpfptr(attr->key, uattr.is_kernel); struct bpf_map *map; - struct fd f; void *key; int err; if (CHECK_ATTR(BPF_MAP_DELETE_ELEM)) return -EINVAL; - f = fdget(ufd); + CLASS(fd, f)(attr->map_fd); map = __bpf_map_get(f); if (IS_ERR(map)) return PTR_ERR(map); - - if (!(f.file->f_mode & FMODE_CAN_WRITE)) { + bpf_map_write_active_inc(map); + if (!(map_get_sys_perms(map, f) & FMODE_CAN_WRITE)) { err = -EPERM; goto err_put; } - key = __bpf_copy_key(ukey, map->key_size); + key = ___bpf_copy_key(ukey, map->key_size); if (IS_ERR(key)) { err = PTR_ERR(key); goto err_put; } - if (bpf_map_is_dev_bound(map)) { + if (bpf_map_is_offloaded(map)) { err = bpf_map_offload_delete_elem(map, key); goto out; + } else if (IS_FD_PROG_ARRAY(map) || + map->map_type == BPF_MAP_TYPE_STRUCT_OPS) { + /* These maps require sleepable context */ + err = map->ops->map_delete_elem(map, key); + goto out; } - preempt_disable(); - __this_cpu_inc(bpf_prog_active); + bpf_disable_instrumentation(); rcu_read_lock(); err = map->ops->map_delete_elem(map, key); rcu_read_unlock(); - __this_cpu_dec(bpf_prog_active); - preempt_enable(); - maybe_wait_bpf_programs(map); + bpf_enable_instrumentation(); + if (!err) + maybe_wait_bpf_programs(map); out: - kfree(key); + kvfree(key); err_put: - fdput(f); + bpf_map_write_active_dec(map); return err; } @@ -939,41 +1887,34 @@ static int map_get_next_key(union bpf_attr *attr) { void __user *ukey = u64_to_user_ptr(attr->key); void __user *unext_key = u64_to_user_ptr(attr->next_key); - int ufd = attr->map_fd; struct bpf_map *map; void *key, *next_key; - struct fd f; int err; if (CHECK_ATTR(BPF_MAP_GET_NEXT_KEY)) return -EINVAL; - f = fdget(ufd); + CLASS(fd, f)(attr->map_fd); map = __bpf_map_get(f); if (IS_ERR(map)) return PTR_ERR(map); - - if (!(f.file->f_mode & FMODE_CAN_READ)) { - err = -EPERM; - goto err_put; - } + if (!(map_get_sys_perms(map, f) & FMODE_CAN_READ)) + return -EPERM; if (ukey) { key = __bpf_copy_key(ukey, map->key_size); - if (IS_ERR(key)) { - err = PTR_ERR(key); - goto err_put; - } + if (IS_ERR(key)) + return PTR_ERR(key); } else { key = NULL; } err = -ENOMEM; - next_key = kmalloc(map->key_size, GFP_USER); + next_key = kvmalloc(map->key_size, GFP_USER); if (!next_key) goto free_key; - if (bpf_map_is_dev_bound(map)) { + if (bpf_map_is_offloaded(map)) { err = bpf_map_offload_get_next_key(map, key, next_key); goto out; } @@ -992,84 +1933,353 @@ out: err = 0; free_next_key: - kfree(next_key); + kvfree(next_key); free_key: - kfree(key); -err_put: - fdput(f); + kvfree(key); + return err; +} + +int generic_map_delete_batch(struct bpf_map *map, + const union bpf_attr *attr, + union bpf_attr __user *uattr) +{ + void __user *keys = u64_to_user_ptr(attr->batch.keys); + u32 cp, max_count; + int err = 0; + void *key; + + if (attr->batch.elem_flags & ~BPF_F_LOCK) + return -EINVAL; + + if ((attr->batch.elem_flags & BPF_F_LOCK) && + !btf_record_has_field(map->record, BPF_SPIN_LOCK)) { + return -EINVAL; + } + + max_count = attr->batch.count; + if (!max_count) + return 0; + + if (put_user(0, &uattr->batch.count)) + return -EFAULT; + + key = kvmalloc(map->key_size, GFP_USER | __GFP_NOWARN); + if (!key) + return -ENOMEM; + + for (cp = 0; cp < max_count; cp++) { + err = -EFAULT; + if (copy_from_user(key, keys + cp * map->key_size, + map->key_size)) + break; + + if (bpf_map_is_offloaded(map)) { + err = bpf_map_offload_delete_elem(map, key); + break; + } + + bpf_disable_instrumentation(); + rcu_read_lock(); + err = map->ops->map_delete_elem(map, key); + rcu_read_unlock(); + bpf_enable_instrumentation(); + if (err) + break; + cond_resched(); + } + if (copy_to_user(&uattr->batch.count, &cp, sizeof(cp))) + err = -EFAULT; + + kvfree(key); + return err; } -#define BPF_MAP_LOOKUP_AND_DELETE_ELEM_LAST_FIELD value +int generic_map_update_batch(struct bpf_map *map, struct file *map_file, + const union bpf_attr *attr, + union bpf_attr __user *uattr) +{ + void __user *values = u64_to_user_ptr(attr->batch.values); + void __user *keys = u64_to_user_ptr(attr->batch.keys); + u32 value_size, cp, max_count; + void *key, *value; + int err = 0; + + err = bpf_map_check_op_flags(map, attr->batch.elem_flags, BPF_F_LOCK); + if (err) + return err; + + value_size = bpf_map_value_size(map); + + max_count = attr->batch.count; + if (!max_count) + return 0; + + if (put_user(0, &uattr->batch.count)) + return -EFAULT; + + key = kvmalloc(map->key_size, GFP_USER | __GFP_NOWARN); + if (!key) + return -ENOMEM; + + value = kvmalloc(value_size, GFP_USER | __GFP_NOWARN); + if (!value) { + kvfree(key); + return -ENOMEM; + } + + for (cp = 0; cp < max_count; cp++) { + err = -EFAULT; + if (copy_from_user(key, keys + cp * map->key_size, + map->key_size) || + copy_from_user(value, values + cp * value_size, value_size)) + break; + + err = bpf_map_update_value(map, map_file, key, value, + attr->batch.elem_flags); + + if (err) + break; + cond_resched(); + } + + if (copy_to_user(&uattr->batch.count, &cp, sizeof(cp))) + err = -EFAULT; + + kvfree(value); + kvfree(key); + + return err; +} + +int generic_map_lookup_batch(struct bpf_map *map, + const union bpf_attr *attr, + union bpf_attr __user *uattr) +{ + void __user *uobatch = u64_to_user_ptr(attr->batch.out_batch); + void __user *ubatch = u64_to_user_ptr(attr->batch.in_batch); + void __user *values = u64_to_user_ptr(attr->batch.values); + void __user *keys = u64_to_user_ptr(attr->batch.keys); + void *buf, *buf_prevkey, *prev_key, *key, *value; + u32 value_size, cp, max_count; + int err; + + err = bpf_map_check_op_flags(map, attr->batch.elem_flags, BPF_F_LOCK); + if (err) + return err; + + value_size = bpf_map_value_size(map); + + max_count = attr->batch.count; + if (!max_count) + return 0; + + if (put_user(0, &uattr->batch.count)) + return -EFAULT; + + buf_prevkey = kvmalloc(map->key_size, GFP_USER | __GFP_NOWARN); + if (!buf_prevkey) + return -ENOMEM; + + buf = kvmalloc(map->key_size + value_size, GFP_USER | __GFP_NOWARN); + if (!buf) { + kvfree(buf_prevkey); + return -ENOMEM; + } + + err = -EFAULT; + prev_key = NULL; + if (ubatch && copy_from_user(buf_prevkey, ubatch, map->key_size)) + goto free_buf; + key = buf; + value = key + map->key_size; + if (ubatch) + prev_key = buf_prevkey; + + for (cp = 0; cp < max_count;) { + rcu_read_lock(); + err = map->ops->map_get_next_key(map, prev_key, key); + rcu_read_unlock(); + if (err) + break; + err = bpf_map_copy_value(map, key, value, + attr->batch.elem_flags); + + if (err == -ENOENT) + goto next_key; + + if (err) + goto free_buf; + + if (copy_to_user(keys + cp * map->key_size, key, + map->key_size)) { + err = -EFAULT; + goto free_buf; + } + if (copy_to_user(values + cp * value_size, value, value_size)) { + err = -EFAULT; + goto free_buf; + } + + cp++; +next_key: + if (!prev_key) + prev_key = buf_prevkey; + + swap(prev_key, key); + cond_resched(); + } + + if (err == -EFAULT) + goto free_buf; + + if ((copy_to_user(&uattr->batch.count, &cp, sizeof(cp)) || + (cp && copy_to_user(uobatch, prev_key, map->key_size)))) + err = -EFAULT; + +free_buf: + kvfree(buf_prevkey); + kvfree(buf); + return err; +} + +#define BPF_MAP_LOOKUP_AND_DELETE_ELEM_LAST_FIELD flags static int map_lookup_and_delete_elem(union bpf_attr *attr) { void __user *ukey = u64_to_user_ptr(attr->key); void __user *uvalue = u64_to_user_ptr(attr->value); - int ufd = attr->map_fd; struct bpf_map *map; void *key, *value; u32 value_size; - struct fd f; int err; if (CHECK_ATTR(BPF_MAP_LOOKUP_AND_DELETE_ELEM)) return -EINVAL; - f = fdget(ufd); + if (attr->flags & ~BPF_F_LOCK) + return -EINVAL; + + CLASS(fd, f)(attr->map_fd); map = __bpf_map_get(f); if (IS_ERR(map)) return PTR_ERR(map); - - if (!(f.file->f_mode & FMODE_CAN_WRITE)) { + bpf_map_write_active_inc(map); + if (!(map_get_sys_perms(map, f) & FMODE_CAN_READ) || + !(map_get_sys_perms(map, f) & FMODE_CAN_WRITE)) { err = -EPERM; goto err_put; } + if (attr->flags && + (map->map_type == BPF_MAP_TYPE_QUEUE || + map->map_type == BPF_MAP_TYPE_STACK)) { + err = -EINVAL; + goto err_put; + } + + if ((attr->flags & BPF_F_LOCK) && + !btf_record_has_field(map->record, BPF_SPIN_LOCK)) { + err = -EINVAL; + goto err_put; + } + key = __bpf_copy_key(ukey, map->key_size); if (IS_ERR(key)) { err = PTR_ERR(key); goto err_put; } - value_size = map->value_size; + value_size = bpf_map_value_size(map); err = -ENOMEM; - value = kmalloc(value_size, GFP_USER | __GFP_NOWARN); + value = kvmalloc(value_size, GFP_USER | __GFP_NOWARN); if (!value) goto free_key; + err = -ENOTSUPP; if (map->map_type == BPF_MAP_TYPE_QUEUE || map->map_type == BPF_MAP_TYPE_STACK) { err = map->ops->map_pop_elem(map, value); - } else { - err = -ENOTSUPP; + } else if (map->map_type == BPF_MAP_TYPE_HASH || + map->map_type == BPF_MAP_TYPE_PERCPU_HASH || + map->map_type == BPF_MAP_TYPE_LRU_HASH || + map->map_type == BPF_MAP_TYPE_LRU_PERCPU_HASH || + map->map_type == BPF_MAP_TYPE_STACK_TRACE) { + if (!bpf_map_is_offloaded(map)) { + bpf_disable_instrumentation(); + rcu_read_lock(); + err = map->ops->map_lookup_and_delete_elem(map, key, value, attr->flags); + rcu_read_unlock(); + bpf_enable_instrumentation(); + } } if (err) goto free_value; - if (copy_to_user(uvalue, value, value_size) != 0) + if (copy_to_user(uvalue, value, value_size) != 0) { + err = -EFAULT; goto free_value; + } err = 0; free_value: - kfree(value); + kvfree(value); free_key: - kfree(key); + kvfree(key); err_put: - fdput(f); + bpf_map_write_active_dec(map); + return err; +} + +#define BPF_MAP_FREEZE_LAST_FIELD map_fd + +static int map_freeze(const union bpf_attr *attr) +{ + int err = 0; + struct bpf_map *map; + + if (CHECK_ATTR(BPF_MAP_FREEZE)) + return -EINVAL; + + CLASS(fd, f)(attr->map_fd); + map = __bpf_map_get(f); + if (IS_ERR(map)) + return PTR_ERR(map); + + if (map->map_type == BPF_MAP_TYPE_STRUCT_OPS || !IS_ERR_OR_NULL(map->record)) + return -ENOTSUPP; + + if (!(map_get_sys_perms(map, f) & FMODE_CAN_WRITE)) + return -EPERM; + + mutex_lock(&map->freeze_mutex); + if (bpf_map_write_active(map)) { + err = -EBUSY; + goto err_put; + } + if (READ_ONCE(map->frozen)) { + err = -EBUSY; + goto err_put; + } + + WRITE_ONCE(map->frozen, true); +err_put: + mutex_unlock(&map->freeze_mutex); return err; } static const struct bpf_prog_ops * const bpf_prog_types[] = { -#define BPF_PROG_TYPE(_id, _name) \ +#define BPF_PROG_TYPE(_id, _name, prog_ctx_type, kern_ctx_type) \ [_id] = & _name ## _prog_ops, #define BPF_MAP_TYPE(_id, _ops) +#define BPF_LINK_TYPE(_id, _name) #include <linux/bpf_types.h> #undef BPF_PROG_TYPE #undef BPF_MAP_TYPE +#undef BPF_LINK_TYPE }; static int find_prog_type(enum bpf_prog_type type, struct bpf_prog *prog) @@ -1083,7 +2293,7 @@ static int find_prog_type(enum bpf_prog_type type, struct bpf_prog *prog) if (!ops) return -EINVAL; - if (!bpf_prog_is_dev_bound(prog->aux)) + if (!bpf_prog_is_offloaded(prog->aux)) prog->aux->ops = ops; else prog->aux->ops = &bpf_offload_prog_ops; @@ -1091,68 +2301,34 @@ static int find_prog_type(enum bpf_prog_type type, struct bpf_prog *prog) return 0; } -/* drop refcnt on maps used by eBPF program and free auxilary data */ -static void free_used_maps(struct bpf_prog_aux *aux) -{ - enum bpf_cgroup_storage_type stype; - int i; - - for_each_cgroup_storage_type(stype) { - if (!aux->cgroup_storage[stype]) - continue; - bpf_cgroup_storage_release(aux->prog, - aux->cgroup_storage[stype]); - } - - for (i = 0; i < aux->used_map_cnt; i++) - bpf_map_put(aux->used_maps[i]); - - kfree(aux->used_maps); -} - -int __bpf_prog_charge(struct user_struct *user, u32 pages) -{ - unsigned long memlock_limit = rlimit(RLIMIT_MEMLOCK) >> PAGE_SHIFT; - unsigned long user_bufs; - - if (user) { - user_bufs = atomic_long_add_return(pages, &user->locked_vm); - if (user_bufs > memlock_limit) { - atomic_long_sub(pages, &user->locked_vm); - return -EPERM; - } - } - - return 0; -} - -void __bpf_prog_uncharge(struct user_struct *user, u32 pages) -{ - if (user) - atomic_long_sub(pages, &user->locked_vm); -} - -static int bpf_prog_charge_memlock(struct bpf_prog *prog) -{ - struct user_struct *user = get_current_user(); - int ret; - - ret = __bpf_prog_charge(user, prog->pages); - if (ret) { - free_uid(user); - return ret; - } +enum bpf_audit { + BPF_AUDIT_LOAD, + BPF_AUDIT_UNLOAD, + BPF_AUDIT_MAX, +}; - prog->aux->user = user; - return 0; -} +static const char * const bpf_audit_str[BPF_AUDIT_MAX] = { + [BPF_AUDIT_LOAD] = "LOAD", + [BPF_AUDIT_UNLOAD] = "UNLOAD", +}; -static void bpf_prog_uncharge_memlock(struct bpf_prog *prog) +static void bpf_audit_prog(const struct bpf_prog *prog, unsigned int op) { - struct user_struct *user = prog->aux->user; + struct audit_context *ctx = NULL; + struct audit_buffer *ab; - __bpf_prog_uncharge(user, prog->pages); - free_uid(user); + if (WARN_ON_ONCE(op >= BPF_AUDIT_MAX)) + return; + if (audit_enabled == AUDIT_OFF) + return; + if (!in_hardirq() && !irqs_disabled()) + ctx = audit_context(); + ab = audit_log_start(ctx, GFP_ATOMIC, AUDIT_BPF); + if (unlikely(!ab)) + return; + audit_log_format(ab, "prog-id=%u op=%s", + prog->aux->id, bpf_audit_str[op]); + audit_log_end(ab); } static int bpf_prog_alloc_id(struct bpf_prog *prog) @@ -1174,8 +2350,10 @@ static int bpf_prog_alloc_id(struct bpf_prog *prog) return id > 0 ? 0 : id; } -void bpf_prog_free_id(struct bpf_prog *prog, bool do_idr_lock) +void bpf_prog_free_id(struct bpf_prog *prog) { + unsigned long flags; + /* cBPF to eBPF migrations are currently not in the idr store. * Offloaded programs are removed from the store when their device * disappears - even if someone grabs an fd to them they are unusable, @@ -1184,47 +2362,75 @@ void bpf_prog_free_id(struct bpf_prog *prog, bool do_idr_lock) if (!prog->aux->id) return; - if (do_idr_lock) - spin_lock_bh(&prog_idr_lock); - else - __acquire(&prog_idr_lock); - + spin_lock_irqsave(&prog_idr_lock, flags); idr_remove(&prog_idr, prog->aux->id); prog->aux->id = 0; - - if (do_idr_lock) - spin_unlock_bh(&prog_idr_lock); - else - __release(&prog_idr_lock); + spin_unlock_irqrestore(&prog_idr_lock, flags); } static void __bpf_prog_put_rcu(struct rcu_head *rcu) { struct bpf_prog_aux *aux = container_of(rcu, struct bpf_prog_aux, rcu); - free_used_maps(aux); - bpf_prog_uncharge_memlock(aux->prog); - security_bpf_prog_free(aux); + kvfree(aux->func_info); + kfree(aux->func_info_aux); + free_uid(aux->user); + security_bpf_prog_free(aux->prog); bpf_prog_free(aux->prog); } -static void __bpf_prog_put(struct bpf_prog *prog, bool do_idr_lock) +static void __bpf_prog_put_noref(struct bpf_prog *prog, bool deferred) { - if (atomic_dec_and_test(&prog->aux->refcnt)) { - /* bpf_prog_free_id() must be called first */ - bpf_prog_free_id(prog, do_idr_lock); - bpf_prog_kallsyms_del_all(prog); - btf_put(prog->aux->btf); - kvfree(prog->aux->func_info); - bpf_prog_free_linfo(prog); + bpf_prog_kallsyms_del_all(prog); + btf_put(prog->aux->btf); + module_put(prog->aux->mod); + kvfree(prog->aux->jited_linfo); + kvfree(prog->aux->linfo); + kfree(prog->aux->kfunc_tab); + kfree(prog->aux->ctx_arg_info); + if (prog->aux->attach_btf) + btf_put(prog->aux->attach_btf); + + if (deferred) { + if (prog->sleepable) + call_rcu_tasks_trace(&prog->aux->rcu, __bpf_prog_put_rcu); + else + call_rcu(&prog->aux->rcu, __bpf_prog_put_rcu); + } else { + __bpf_prog_put_rcu(&prog->aux->rcu); + } +} + +static void bpf_prog_put_deferred(struct work_struct *work) +{ + struct bpf_prog_aux *aux; + struct bpf_prog *prog; - call_rcu(&prog->aux->rcu, __bpf_prog_put_rcu); + aux = container_of(work, struct bpf_prog_aux, work); + prog = aux->prog; + perf_event_bpf_event(prog, PERF_BPF_EVENT_PROG_UNLOAD, 0); + bpf_audit_prog(prog, BPF_AUDIT_UNLOAD); + bpf_prog_free_id(prog); + __bpf_prog_put_noref(prog, true); +} + +static void __bpf_prog_put(struct bpf_prog *prog) +{ + struct bpf_prog_aux *aux = prog->aux; + + if (atomic64_dec_and_test(&aux->refcnt)) { + if (in_hardirq() || irqs_disabled()) { + INIT_WORK(&aux->work, bpf_prog_put_deferred); + schedule_work(&aux->work); + } else { + bpf_prog_put_deferred(&aux->work); + } } } void bpf_prog_put(struct bpf_prog *prog) { - __bpf_prog_put(prog, true); + __bpf_prog_put(prog); } EXPORT_SYMBOL_GPL(bpf_prog_put); @@ -1236,24 +2442,81 @@ static int bpf_prog_release(struct inode *inode, struct file *filp) return 0; } +struct bpf_prog_kstats { + u64 nsecs; + u64 cnt; + u64 misses; +}; + +void notrace bpf_prog_inc_misses_counter(struct bpf_prog *prog) +{ + struct bpf_prog_stats *stats; + unsigned int flags; + + if (unlikely(!prog->stats)) + return; + + stats = this_cpu_ptr(prog->stats); + flags = u64_stats_update_begin_irqsave(&stats->syncp); + u64_stats_inc(&stats->misses); + u64_stats_update_end_irqrestore(&stats->syncp, flags); +} + +static void bpf_prog_get_stats(const struct bpf_prog *prog, + struct bpf_prog_kstats *stats) +{ + u64 nsecs = 0, cnt = 0, misses = 0; + int cpu; + + for_each_possible_cpu(cpu) { + const struct bpf_prog_stats *st; + unsigned int start; + u64 tnsecs, tcnt, tmisses; + + st = per_cpu_ptr(prog->stats, cpu); + do { + start = u64_stats_fetch_begin(&st->syncp); + tnsecs = u64_stats_read(&st->nsecs); + tcnt = u64_stats_read(&st->cnt); + tmisses = u64_stats_read(&st->misses); + } while (u64_stats_fetch_retry(&st->syncp, start)); + nsecs += tnsecs; + cnt += tcnt; + misses += tmisses; + } + stats->nsecs = nsecs; + stats->cnt = cnt; + stats->misses = misses; +} + #ifdef CONFIG_PROC_FS static void bpf_prog_show_fdinfo(struct seq_file *m, struct file *filp) { const struct bpf_prog *prog = filp->private_data; char prog_tag[sizeof(prog->tag) * 2 + 1] = { }; + struct bpf_prog_kstats stats; + bpf_prog_get_stats(prog, &stats); bin2hex(prog_tag, prog->tag, sizeof(prog->tag)); seq_printf(m, "prog_type:\t%u\n" "prog_jited:\t%u\n" "prog_tag:\t%s\n" "memlock:\t%llu\n" - "prog_id:\t%u\n", + "prog_id:\t%u\n" + "run_time_ns:\t%llu\n" + "run_cnt:\t%llu\n" + "recursion_misses:\t%llu\n" + "verified_insns:\t%u\n", prog->type, prog->jited, prog_tag, prog->pages * 1ULL << PAGE_SHIFT, - prog->aux->id); + prog->aux->id, + stats.nsecs, + stats.cnt, + stats.misses, + prog->aux->verified_insns); } #endif @@ -1278,25 +2541,9 @@ int bpf_prog_new_fd(struct bpf_prog *prog) O_RDWR | O_CLOEXEC); } -static struct bpf_prog *____bpf_prog_get(struct fd f) -{ - if (!f.file) - return ERR_PTR(-EBADF); - if (f.file->f_op != &bpf_prog_fops) { - fdput(f); - return ERR_PTR(-EINVAL); - } - - return f.file->private_data; -} - -struct bpf_prog *bpf_prog_add(struct bpf_prog *prog, int i) +void bpf_prog_add(struct bpf_prog *prog, int i) { - if (atomic_add_return(i, &prog->aux->refcnt) > BPF_MAX_REFCNT) { - atomic_sub(i, &prog->aux->refcnt); - return ERR_PTR(-EBUSY); - } - return prog; + atomic64_add(i, &prog->aux->refcnt); } EXPORT_SYMBOL_GPL(bpf_prog_add); @@ -1307,13 +2554,13 @@ void bpf_prog_sub(struct bpf_prog *prog, int i) * path holds a reference to the program, thus atomic_sub() can * be safely used in such cases! */ - WARN_ON(atomic_sub_return(i, &prog->aux->refcnt) == 0); + WARN_ON(atomic64_sub_return(i, &prog->aux->refcnt) == 0); } EXPORT_SYMBOL_GPL(bpf_prog_sub); -struct bpf_prog *bpf_prog_inc(struct bpf_prog *prog) +void bpf_prog_inc(struct bpf_prog *prog) { - return bpf_prog_add(prog, 1); + atomic64_inc(&prog->aux->refcnt); } EXPORT_SYMBOL_GPL(bpf_prog_inc); @@ -1322,12 +2569,7 @@ struct bpf_prog *bpf_prog_inc_not_zero(struct bpf_prog *prog) { int refold; - refold = atomic_fetch_add_unless(&prog->aux->refcnt, 1, 0); - - if (refold >= BPF_MAX_REFCNT) { - __bpf_prog_put(prog, false); - return ERR_PTR(-EBUSY); - } + refold = atomic64_fetch_add_unless(&prog->aux->refcnt, 1, 0); if (!refold) return ERR_PTR(-ENOENT); @@ -1345,7 +2587,7 @@ bool bpf_prog_get_ok(struct bpf_prog *prog, if (prog->type != *attach_type) return false; - if (bpf_prog_is_dev_bound(prog->aux) && !attach_drv) + if (bpf_prog_is_offloaded(prog->aux) && !attach_drv) return false; return true; @@ -1354,20 +2596,19 @@ bool bpf_prog_get_ok(struct bpf_prog *prog, static struct bpf_prog *__bpf_prog_get(u32 ufd, enum bpf_prog_type *attach_type, bool attach_drv) { - struct fd f = fdget(ufd); + CLASS(fd, f)(ufd); struct bpf_prog *prog; - prog = ____bpf_prog_get(f); - if (IS_ERR(prog)) - return prog; - if (!bpf_prog_get_ok(prog, attach_type, attach_drv)) { - prog = ERR_PTR(-EINVAL); - goto out; - } + if (fd_empty(f)) + return ERR_PTR(-EBADF); + if (fd_file(f)->f_op != &bpf_prog_fops) + return ERR_PTR(-EINVAL); - prog = bpf_prog_inc(prog); -out: - fdput(f); + prog = fd_file(f)->private_data; + if (!bpf_prog_get_ok(prog, attach_type, attach_drv)) + return ERR_PTR(-EINVAL); + + bpf_prog_inc(prog); return prog; } @@ -1406,17 +2647,50 @@ static void bpf_prog_load_fixup_attach_type(union bpf_attr *attr) attr->expected_attach_type = BPF_CGROUP_INET_SOCK_CREATE; break; + case BPF_PROG_TYPE_SK_REUSEPORT: + if (!attr->expected_attach_type) + attr->expected_attach_type = + BPF_SK_REUSEPORT_SELECT; + break; } } static int -bpf_prog_load_check_attach_type(enum bpf_prog_type prog_type, - enum bpf_attach_type expected_attach_type) +bpf_prog_load_check_attach(enum bpf_prog_type prog_type, + enum bpf_attach_type expected_attach_type, + struct btf *attach_btf, u32 btf_id, + struct bpf_prog *dst_prog) { + if (btf_id) { + if (btf_id > BTF_MAX_TYPE) + return -EINVAL; + + if (!attach_btf && !dst_prog) + return -EINVAL; + + switch (prog_type) { + case BPF_PROG_TYPE_TRACING: + case BPF_PROG_TYPE_LSM: + case BPF_PROG_TYPE_STRUCT_OPS: + case BPF_PROG_TYPE_EXT: + break; + default: + return -EINVAL; + } + } + + if (attach_btf && (!btf_id || dst_prog)) + return -EINVAL; + + if (dst_prog && prog_type != BPF_PROG_TYPE_TRACING && + prog_type != BPF_PROG_TYPE_EXT) + return -EINVAL; + switch (prog_type) { case BPF_PROG_TYPE_CGROUP_SOCK: switch (expected_attach_type) { case BPF_CGROUP_INET_SOCK_CREATE: + case BPF_CGROUP_INET_SOCK_RELEASE: case BPF_CGROUP_INET4_POST_BIND: case BPF_CGROUP_INET6_POST_BIND: return 0; @@ -1429,107 +2703,389 @@ bpf_prog_load_check_attach_type(enum bpf_prog_type prog_type, case BPF_CGROUP_INET6_BIND: case BPF_CGROUP_INET4_CONNECT: case BPF_CGROUP_INET6_CONNECT: + case BPF_CGROUP_UNIX_CONNECT: + case BPF_CGROUP_INET4_GETPEERNAME: + case BPF_CGROUP_INET6_GETPEERNAME: + case BPF_CGROUP_UNIX_GETPEERNAME: + case BPF_CGROUP_INET4_GETSOCKNAME: + case BPF_CGROUP_INET6_GETSOCKNAME: + case BPF_CGROUP_UNIX_GETSOCKNAME: case BPF_CGROUP_UDP4_SENDMSG: case BPF_CGROUP_UDP6_SENDMSG: + case BPF_CGROUP_UNIX_SENDMSG: + case BPF_CGROUP_UDP4_RECVMSG: + case BPF_CGROUP_UDP6_RECVMSG: + case BPF_CGROUP_UNIX_RECVMSG: return 0; default: return -EINVAL; } + case BPF_PROG_TYPE_CGROUP_SKB: + switch (expected_attach_type) { + case BPF_CGROUP_INET_INGRESS: + case BPF_CGROUP_INET_EGRESS: + return 0; + default: + return -EINVAL; + } + case BPF_PROG_TYPE_CGROUP_SOCKOPT: + switch (expected_attach_type) { + case BPF_CGROUP_SETSOCKOPT: + case BPF_CGROUP_GETSOCKOPT: + return 0; + default: + return -EINVAL; + } + case BPF_PROG_TYPE_SK_LOOKUP: + if (expected_attach_type == BPF_SK_LOOKUP) + return 0; + return -EINVAL; + case BPF_PROG_TYPE_SK_REUSEPORT: + switch (expected_attach_type) { + case BPF_SK_REUSEPORT_SELECT: + case BPF_SK_REUSEPORT_SELECT_OR_MIGRATE: + return 0; + default: + return -EINVAL; + } + case BPF_PROG_TYPE_NETFILTER: + if (expected_attach_type == BPF_NETFILTER) + return 0; + return -EINVAL; + case BPF_PROG_TYPE_SYSCALL: + case BPF_PROG_TYPE_EXT: + if (expected_attach_type) + return -EINVAL; + fallthrough; default: return 0; } } +static bool is_net_admin_prog_type(enum bpf_prog_type prog_type) +{ + switch (prog_type) { + case BPF_PROG_TYPE_SCHED_CLS: + case BPF_PROG_TYPE_SCHED_ACT: + case BPF_PROG_TYPE_XDP: + case BPF_PROG_TYPE_LWT_IN: + case BPF_PROG_TYPE_LWT_OUT: + case BPF_PROG_TYPE_LWT_XMIT: + case BPF_PROG_TYPE_LWT_SEG6LOCAL: + case BPF_PROG_TYPE_SK_SKB: + case BPF_PROG_TYPE_SK_MSG: + case BPF_PROG_TYPE_FLOW_DISSECTOR: + case BPF_PROG_TYPE_CGROUP_DEVICE: + case BPF_PROG_TYPE_CGROUP_SOCK: + case BPF_PROG_TYPE_CGROUP_SOCK_ADDR: + case BPF_PROG_TYPE_CGROUP_SOCKOPT: + case BPF_PROG_TYPE_CGROUP_SYSCTL: + case BPF_PROG_TYPE_SOCK_OPS: + case BPF_PROG_TYPE_EXT: /* extends any prog */ + case BPF_PROG_TYPE_NETFILTER: + return true; + case BPF_PROG_TYPE_CGROUP_SKB: + /* always unpriv */ + case BPF_PROG_TYPE_SK_REUSEPORT: + /* equivalent to SOCKET_FILTER. need CAP_BPF only */ + default: + return false; + } +} + +static bool is_perfmon_prog_type(enum bpf_prog_type prog_type) +{ + switch (prog_type) { + case BPF_PROG_TYPE_KPROBE: + case BPF_PROG_TYPE_TRACEPOINT: + case BPF_PROG_TYPE_PERF_EVENT: + case BPF_PROG_TYPE_RAW_TRACEPOINT: + case BPF_PROG_TYPE_RAW_TRACEPOINT_WRITABLE: + case BPF_PROG_TYPE_TRACING: + case BPF_PROG_TYPE_LSM: + case BPF_PROG_TYPE_STRUCT_OPS: /* has access to struct sock */ + case BPF_PROG_TYPE_EXT: /* extends any prog */ + return true; + default: + return false; + } +} + +static int bpf_prog_verify_signature(struct bpf_prog *prog, union bpf_attr *attr, + bool is_kernel) +{ + bpfptr_t usig = make_bpfptr(attr->signature, is_kernel); + struct bpf_dynptr_kern sig_ptr, insns_ptr; + struct bpf_key *key = NULL; + void *sig; + int err = 0; + + if (system_keyring_id_check(attr->keyring_id) == 0) + key = bpf_lookup_system_key(attr->keyring_id); + else + key = bpf_lookup_user_key(attr->keyring_id, 0); + + if (!key) + return -EINVAL; + + sig = kvmemdup_bpfptr(usig, attr->signature_size); + if (IS_ERR(sig)) { + bpf_key_put(key); + return -ENOMEM; + } + + bpf_dynptr_init(&sig_ptr, sig, BPF_DYNPTR_TYPE_LOCAL, 0, + attr->signature_size); + bpf_dynptr_init(&insns_ptr, prog->insnsi, BPF_DYNPTR_TYPE_LOCAL, 0, + prog->len * sizeof(struct bpf_insn)); + + err = bpf_verify_pkcs7_signature((struct bpf_dynptr *)&insns_ptr, + (struct bpf_dynptr *)&sig_ptr, key); + + bpf_key_put(key); + kvfree(sig); + return err; +} + +static int bpf_prog_mark_insn_arrays_ready(struct bpf_prog *prog) +{ + int err; + int i; + + for (i = 0; i < prog->aux->used_map_cnt; i++) { + if (prog->aux->used_maps[i]->map_type != BPF_MAP_TYPE_INSN_ARRAY) + continue; + + err = bpf_insn_array_ready(prog->aux->used_maps[i]); + if (err) + return err; + } + + return 0; +} + /* last field in 'union bpf_attr' used by this command */ -#define BPF_PROG_LOAD_LAST_FIELD line_info_cnt +#define BPF_PROG_LOAD_LAST_FIELD keyring_id -static int bpf_prog_load(union bpf_attr *attr, union bpf_attr __user *uattr) +static int bpf_prog_load(union bpf_attr *attr, bpfptr_t uattr, u32 uattr_size) { enum bpf_prog_type type = attr->prog_type; - struct bpf_prog *prog; + struct bpf_prog *prog, *dst_prog = NULL; + struct btf *attach_btf = NULL; + struct bpf_token *token = NULL; + bool bpf_cap; int err; char license[128]; - bool is_gpl; if (CHECK_ATTR(BPF_PROG_LOAD)) return -EINVAL; - if (attr->prog_flags & ~(BPF_F_STRICT_ALIGNMENT | BPF_F_ANY_ALIGNMENT)) + if (attr->prog_flags & ~(BPF_F_STRICT_ALIGNMENT | + BPF_F_ANY_ALIGNMENT | + BPF_F_TEST_STATE_FREQ | + BPF_F_SLEEPABLE | + BPF_F_TEST_RND_HI32 | + BPF_F_XDP_HAS_FRAGS | + BPF_F_XDP_DEV_BOUND_ONLY | + BPF_F_TEST_REG_INVARIANTS | + BPF_F_TOKEN_FD)) return -EINVAL; - if (!IS_ENABLED(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && - (attr->prog_flags & BPF_F_ANY_ALIGNMENT) && - !capable(CAP_SYS_ADMIN)) - return -EPERM; + bpf_prog_load_fixup_attach_type(attr); - /* copy eBPF program license from user space */ - if (strncpy_from_user(license, u64_to_user_ptr(attr->license), - sizeof(license) - 1) < 0) - return -EFAULT; - license[sizeof(license) - 1] = 0; + if (attr->prog_flags & BPF_F_TOKEN_FD) { + token = bpf_token_get_from_fd(attr->prog_token_fd); + if (IS_ERR(token)) + return PTR_ERR(token); + /* if current token doesn't grant prog loading permissions, + * then we can't use this token, so ignore it and rely on + * system-wide capabilities checks + */ + if (!bpf_token_allow_cmd(token, BPF_PROG_LOAD) || + !bpf_token_allow_prog_type(token, attr->prog_type, + attr->expected_attach_type)) { + bpf_token_put(token); + token = NULL; + } + } - /* eBPF programs must be GPL compatible to use GPL-ed functions */ - is_gpl = license_is_gpl_compatible(license); + bpf_cap = bpf_token_capable(token, CAP_BPF); + err = -EPERM; - if (attr->insn_cnt == 0 || attr->insn_cnt > BPF_MAXINSNS) - return -E2BIG; + if (!IS_ENABLED(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && + (attr->prog_flags & BPF_F_ANY_ALIGNMENT) && + !bpf_cap) + goto put_token; + + /* Intent here is for unprivileged_bpf_disabled to block BPF program + * creation for unprivileged users; other actions depend + * on fd availability and access to bpffs, so are dependent on + * object creation success. Even with unprivileged BPF disabled, + * capability checks are still carried out for these + * and other operations. + */ + if (sysctl_unprivileged_bpf_disabled && !bpf_cap) + goto put_token; + + if (attr->insn_cnt == 0 || + attr->insn_cnt > (bpf_cap ? BPF_COMPLEXITY_LIMIT_INSNS : BPF_MAXINSNS)) { + err = -E2BIG; + goto put_token; + } if (type != BPF_PROG_TYPE_SOCKET_FILTER && type != BPF_PROG_TYPE_CGROUP_SKB && - !capable(CAP_SYS_ADMIN)) - return -EPERM; + !bpf_cap) + goto put_token; - bpf_prog_load_fixup_attach_type(attr); - if (bpf_prog_load_check_attach_type(type, attr->expected_attach_type)) - return -EINVAL; + if (is_net_admin_prog_type(type) && !bpf_token_capable(token, CAP_NET_ADMIN)) + goto put_token; + if (is_perfmon_prog_type(type) && !bpf_token_capable(token, CAP_PERFMON)) + goto put_token; + + /* attach_prog_fd/attach_btf_obj_fd can specify fd of either bpf_prog + * or btf, we need to check which one it is + */ + if (attr->attach_prog_fd) { + dst_prog = bpf_prog_get(attr->attach_prog_fd); + if (IS_ERR(dst_prog)) { + dst_prog = NULL; + attach_btf = btf_get_by_fd(attr->attach_btf_obj_fd); + if (IS_ERR(attach_btf)) { + err = -EINVAL; + goto put_token; + } + if (!btf_is_kernel(attach_btf)) { + /* attaching through specifying bpf_prog's BTF + * objects directly might be supported eventually + */ + btf_put(attach_btf); + err = -ENOTSUPP; + goto put_token; + } + } + } else if (attr->attach_btf_id) { + /* fall back to vmlinux BTF, if BTF type ID is specified */ + attach_btf = bpf_get_btf_vmlinux(); + if (IS_ERR(attach_btf)) { + err = PTR_ERR(attach_btf); + goto put_token; + } + if (!attach_btf) { + err = -EINVAL; + goto put_token; + } + btf_get(attach_btf); + } + + if (bpf_prog_load_check_attach(type, attr->expected_attach_type, + attach_btf, attr->attach_btf_id, + dst_prog)) { + if (dst_prog) + bpf_prog_put(dst_prog); + if (attach_btf) + btf_put(attach_btf); + err = -EINVAL; + goto put_token; + } /* plain bpf_prog allocation */ prog = bpf_prog_alloc(bpf_prog_size(attr->insn_cnt), GFP_USER); - if (!prog) - return -ENOMEM; + if (!prog) { + if (dst_prog) + bpf_prog_put(dst_prog); + if (attach_btf) + btf_put(attach_btf); + err = -EINVAL; + goto put_token; + } prog->expected_attach_type = attr->expected_attach_type; - - prog->aux->offload_requested = !!attr->prog_ifindex; - - err = security_bpf_prog_alloc(prog->aux); - if (err) - goto free_prog_nouncharge; - - err = bpf_prog_charge_memlock(prog); - if (err) - goto free_prog_sec; - + prog->sleepable = !!(attr->prog_flags & BPF_F_SLEEPABLE); + prog->aux->attach_btf = attach_btf; + prog->aux->attach_btf_id = attr->attach_btf_id; + prog->aux->dst_prog = dst_prog; + prog->aux->dev_bound = !!attr->prog_ifindex; + prog->aux->xdp_has_frags = attr->prog_flags & BPF_F_XDP_HAS_FRAGS; + + /* move token into prog->aux, reuse taken refcnt */ + prog->aux->token = token; + token = NULL; + + prog->aux->user = get_current_user(); prog->len = attr->insn_cnt; err = -EFAULT; - if (copy_from_user(prog->insns, u64_to_user_ptr(attr->insns), - bpf_prog_insn_size(prog)) != 0) + if (copy_from_bpfptr(prog->insns, + make_bpfptr(attr->insns, uattr.is_kernel), + bpf_prog_insn_size(prog)) != 0) + goto free_prog; + /* copy eBPF program license from user space */ + if (strncpy_from_bpfptr(license, + make_bpfptr(attr->license, uattr.is_kernel), + sizeof(license) - 1) < 0) goto free_prog; + license[sizeof(license) - 1] = 0; + + /* eBPF programs must be GPL compatible to use GPL-ed functions */ + prog->gpl_compatible = license_is_gpl_compatible(license) ? 1 : 0; + + if (attr->signature) { + err = bpf_prog_verify_signature(prog, attr, uattr.is_kernel); + if (err) + goto free_prog; + } prog->orig_prog = NULL; prog->jited = 0; - atomic_set(&prog->aux->refcnt, 1); - prog->gpl_compatible = is_gpl ? 1 : 0; + atomic64_set(&prog->aux->refcnt, 1); if (bpf_prog_is_dev_bound(prog->aux)) { - err = bpf_prog_offload_init(prog, attr); + err = bpf_prog_dev_bound_init(prog, attr); + if (err) + goto free_prog; + } + + if (type == BPF_PROG_TYPE_EXT && dst_prog && + bpf_prog_is_dev_bound(dst_prog->aux)) { + err = bpf_prog_dev_bound_inherit(prog, dst_prog); if (err) goto free_prog; } + /* + * Bookkeeping for managing the program attachment chain. + * + * It might be tempting to set attach_tracing_prog flag at the attachment + * time, but this will not prevent from loading bunch of tracing prog + * first, then attach them one to another. + * + * The flag attach_tracing_prog is set for the whole program lifecycle, and + * doesn't have to be cleared in bpf_tracing_link_release, since tracing + * programs cannot change attachment target. + */ + if (type == BPF_PROG_TYPE_TRACING && dst_prog && + dst_prog->type == BPF_PROG_TYPE_TRACING) { + prog->aux->attach_tracing_prog = true; + } + /* find program type: socket_filter vs tracing_filter */ err = find_prog_type(type, prog); if (err < 0) goto free_prog; - prog->aux->load_time = ktime_get_boot_ns(); - err = bpf_obj_name_cpy(prog->aux->name, attr->prog_name); - if (err) + prog->aux->load_time = ktime_get_boottime_ns(); + err = bpf_obj_name_cpy(prog->aux->name, attr->prog_name, + sizeof(attr->prog_name)); + if (err < 0) goto free_prog; + err = security_bpf_prog_load(prog, attr, token, uattr.is_kernel); + if (err) + goto free_prog_sec; + /* run eBPF verifier */ - err = bpf_check(&prog, attr, uattr); + err = bpf_check(&prog, attr, uattr, uattr_size); if (err < 0) goto free_used_maps; @@ -1537,211 +3093,1414 @@ static int bpf_prog_load(union bpf_attr *attr, union bpf_attr __user *uattr) if (err < 0) goto free_used_maps; + err = bpf_prog_mark_insn_arrays_ready(prog); + if (err < 0) + goto free_used_maps; + err = bpf_prog_alloc_id(prog); if (err) goto free_used_maps; + /* Upon success of bpf_prog_alloc_id(), the BPF prog is + * effectively publicly exposed. However, retrieving via + * bpf_prog_get_fd_by_id() will take another reference, + * therefore it cannot be gone underneath us. + * + * Only for the time /after/ successful bpf_prog_new_fd() + * and before returning to userspace, we might just hold + * one reference and any parallel close on that fd could + * rip everything out. Hence, below notifications must + * happen before bpf_prog_new_fd(). + * + * Also, any failure handling from this point onwards must + * be using bpf_prog_put() given the program is exposed. + */ + bpf_prog_kallsyms_add(prog); + perf_event_bpf_event(prog, PERF_BPF_EVENT_PROG_LOAD, 0); + bpf_audit_prog(prog, BPF_AUDIT_LOAD); + err = bpf_prog_new_fd(prog); - if (err < 0) { - /* failed to allocate fd. - * bpf_prog_put() is needed because the above - * bpf_prog_alloc_id() has published the prog - * to the userspace and the userspace may - * have refcnt-ed it through BPF_PROG_GET_FD_BY_ID. - */ + if (err < 0) bpf_prog_put(prog); - return err; - } - - bpf_prog_kallsyms_add(prog); return err; free_used_maps: - bpf_prog_free_linfo(prog); - kvfree(prog->aux->func_info); - btf_put(prog->aux->btf); - bpf_prog_kallsyms_del_subprogs(prog); - free_used_maps(prog->aux); -free_prog: - bpf_prog_uncharge_memlock(prog); + /* In case we have subprogs, we need to wait for a grace + * period before we can tear down JIT memory since symbols + * are already exposed under kallsyms. + */ + __bpf_prog_put_noref(prog, prog->aux->real_func_cnt); + return err; + free_prog_sec: - security_bpf_prog_free(prog->aux); -free_prog_nouncharge: + security_bpf_prog_free(prog); +free_prog: + free_uid(prog->aux->user); + if (prog->aux->attach_btf) + btf_put(prog->aux->attach_btf); bpf_prog_free(prog); +put_token: + bpf_token_put(token); return err; } -#define BPF_OBJ_LAST_FIELD file_flags +#define BPF_OBJ_LAST_FIELD path_fd static int bpf_obj_pin(const union bpf_attr *attr) { - if (CHECK_ATTR(BPF_OBJ) || attr->file_flags != 0) + int path_fd; + + if (CHECK_ATTR(BPF_OBJ) || attr->file_flags & ~BPF_F_PATH_FD) return -EINVAL; - return bpf_obj_pin_user(attr->bpf_fd, u64_to_user_ptr(attr->pathname)); + /* path_fd has to be accompanied by BPF_F_PATH_FD flag */ + if (!(attr->file_flags & BPF_F_PATH_FD) && attr->path_fd) + return -EINVAL; + + path_fd = attr->file_flags & BPF_F_PATH_FD ? attr->path_fd : AT_FDCWD; + return bpf_obj_pin_user(attr->bpf_fd, path_fd, + u64_to_user_ptr(attr->pathname)); } static int bpf_obj_get(const union bpf_attr *attr) { + int path_fd; + if (CHECK_ATTR(BPF_OBJ) || attr->bpf_fd != 0 || - attr->file_flags & ~BPF_OBJ_FLAG_MASK) + attr->file_flags & ~(BPF_OBJ_FLAG_MASK | BPF_F_PATH_FD)) + return -EINVAL; + + /* path_fd has to be accompanied by BPF_F_PATH_FD flag */ + if (!(attr->file_flags & BPF_F_PATH_FD) && attr->path_fd) return -EINVAL; - return bpf_obj_get_user(u64_to_user_ptr(attr->pathname), + path_fd = attr->file_flags & BPF_F_PATH_FD ? attr->path_fd : AT_FDCWD; + return bpf_obj_get_user(path_fd, u64_to_user_ptr(attr->pathname), attr->file_flags); } -struct bpf_raw_tracepoint { - struct bpf_raw_event_map *btp; - struct bpf_prog *prog; -}; +/* bpf_link_init_sleepable() allows to specify whether BPF link itself has + * "sleepable" semantics, which normally would mean that BPF link's attach + * hook can dereference link or link's underlying program for some time after + * detachment due to RCU Tasks Trace-based lifetime protection scheme. + * BPF program itself can be non-sleepable, yet, because it's transitively + * reachable through BPF link, its freeing has to be delayed until after RCU + * Tasks Trace GP. + */ +void bpf_link_init_sleepable(struct bpf_link *link, enum bpf_link_type type, + const struct bpf_link_ops *ops, struct bpf_prog *prog, + enum bpf_attach_type attach_type, bool sleepable) +{ + WARN_ON(ops->dealloc && ops->dealloc_deferred); + atomic64_set(&link->refcnt, 1); + link->type = type; + link->sleepable = sleepable; + link->id = 0; + link->ops = ops; + link->prog = prog; + link->attach_type = attach_type; +} + +void bpf_link_init(struct bpf_link *link, enum bpf_link_type type, + const struct bpf_link_ops *ops, struct bpf_prog *prog, + enum bpf_attach_type attach_type) +{ + bpf_link_init_sleepable(link, type, ops, prog, attach_type, false); +} + +static void bpf_link_free_id(int id) +{ + if (!id) + return; + + spin_lock_bh(&link_idr_lock); + idr_remove(&link_idr, id); + spin_unlock_bh(&link_idr_lock); +} + +/* Clean up bpf_link and corresponding anon_inode file and FD. After + * anon_inode is created, bpf_link can't be just kfree()'d due to deferred + * anon_inode's release() call. This helper marks bpf_link as + * defunct, releases anon_inode file and puts reserved FD. bpf_prog's refcnt + * is not decremented, it's the responsibility of a calling code that failed + * to complete bpf_link initialization. + * This helper eventually calls link's dealloc callback, but does not call + * link's release callback. + */ +void bpf_link_cleanup(struct bpf_link_primer *primer) +{ + primer->link->prog = NULL; + bpf_link_free_id(primer->id); + fput(primer->file); + put_unused_fd(primer->fd); +} + +void bpf_link_inc(struct bpf_link *link) +{ + atomic64_inc(&link->refcnt); +} + +static void bpf_link_dealloc(struct bpf_link *link) +{ + /* now that we know that bpf_link itself can't be reached, put underlying BPF program */ + if (link->prog) + bpf_prog_put(link->prog); + + /* free bpf_link and its containing memory */ + if (link->ops->dealloc_deferred) + link->ops->dealloc_deferred(link); + else + link->ops->dealloc(link); +} + +static void bpf_link_defer_dealloc_rcu_gp(struct rcu_head *rcu) +{ + struct bpf_link *link = container_of(rcu, struct bpf_link, rcu); + + bpf_link_dealloc(link); +} -static int bpf_raw_tracepoint_release(struct inode *inode, struct file *filp) +static void bpf_link_defer_dealloc_mult_rcu_gp(struct rcu_head *rcu) { - struct bpf_raw_tracepoint *raw_tp = filp->private_data; + if (rcu_trace_implies_rcu_gp()) + bpf_link_defer_dealloc_rcu_gp(rcu); + else + call_rcu(rcu, bpf_link_defer_dealloc_rcu_gp); +} - if (raw_tp->prog) { - bpf_probe_unregister(raw_tp->btp, raw_tp->prog); - bpf_prog_put(raw_tp->prog); +/* bpf_link_free is guaranteed to be called from process context */ +static void bpf_link_free(struct bpf_link *link) +{ + const struct bpf_link_ops *ops = link->ops; + + bpf_link_free_id(link->id); + /* detach BPF program, clean up used resources */ + if (link->prog) + ops->release(link); + if (ops->dealloc_deferred) { + /* Schedule BPF link deallocation, which will only then + * trigger putting BPF program refcount. + * If underlying BPF program is sleepable or BPF link's target + * attach hookpoint is sleepable or otherwise requires RCU GPs + * to ensure link and its underlying BPF program is not + * reachable anymore, we need to first wait for RCU tasks + * trace sync, and then go through "classic" RCU grace period + */ + if (link->sleepable || (link->prog && link->prog->sleepable)) + call_rcu_tasks_trace(&link->rcu, bpf_link_defer_dealloc_mult_rcu_gp); + else + call_rcu(&link->rcu, bpf_link_defer_dealloc_rcu_gp); + } else if (ops->dealloc) { + bpf_link_dealloc(link); } - bpf_put_raw_tracepoint(raw_tp->btp); - kfree(raw_tp); +} + +static void bpf_link_put_deferred(struct work_struct *work) +{ + struct bpf_link *link = container_of(work, struct bpf_link, work); + + bpf_link_free(link); +} + +/* bpf_link_put might be called from atomic context. It needs to be called + * from sleepable context in order to acquire sleeping locks during the process. + */ +void bpf_link_put(struct bpf_link *link) +{ + if (!atomic64_dec_and_test(&link->refcnt)) + return; + + INIT_WORK(&link->work, bpf_link_put_deferred); + schedule_work(&link->work); +} +EXPORT_SYMBOL(bpf_link_put); + +static void bpf_link_put_direct(struct bpf_link *link) +{ + if (!atomic64_dec_and_test(&link->refcnt)) + return; + bpf_link_free(link); +} + +static int bpf_link_release(struct inode *inode, struct file *filp) +{ + struct bpf_link *link = filp->private_data; + + bpf_link_put_direct(link); return 0; } -static const struct file_operations bpf_raw_tp_fops = { - .release = bpf_raw_tracepoint_release, +#ifdef CONFIG_PROC_FS +#define BPF_PROG_TYPE(_id, _name, prog_ctx_type, kern_ctx_type) +#define BPF_MAP_TYPE(_id, _ops) +#define BPF_LINK_TYPE(_id, _name) [_id] = #_name, +static const char *bpf_link_type_strs[] = { + [BPF_LINK_TYPE_UNSPEC] = "<invalid>", +#include <linux/bpf_types.h> +}; +#undef BPF_PROG_TYPE +#undef BPF_MAP_TYPE +#undef BPF_LINK_TYPE + +static void bpf_link_show_fdinfo(struct seq_file *m, struct file *filp) +{ + const struct bpf_link *link = filp->private_data; + const struct bpf_prog *prog = link->prog; + enum bpf_link_type type = link->type; + char prog_tag[sizeof(prog->tag) * 2 + 1] = { }; + + if (type < ARRAY_SIZE(bpf_link_type_strs) && bpf_link_type_strs[type]) { + if (link->type == BPF_LINK_TYPE_KPROBE_MULTI) + seq_printf(m, "link_type:\t%s\n", link->flags == BPF_F_KPROBE_MULTI_RETURN ? + "kretprobe_multi" : "kprobe_multi"); + else if (link->type == BPF_LINK_TYPE_UPROBE_MULTI) + seq_printf(m, "link_type:\t%s\n", link->flags == BPF_F_UPROBE_MULTI_RETURN ? + "uretprobe_multi" : "uprobe_multi"); + else + seq_printf(m, "link_type:\t%s\n", bpf_link_type_strs[type]); + } else { + WARN_ONCE(1, "missing BPF_LINK_TYPE(...) for link type %u\n", type); + seq_printf(m, "link_type:\t<%u>\n", type); + } + seq_printf(m, "link_id:\t%u\n", link->id); + + if (prog) { + bin2hex(prog_tag, prog->tag, sizeof(prog->tag)); + seq_printf(m, + "prog_tag:\t%s\n" + "prog_id:\t%u\n", + prog_tag, + prog->aux->id); + } + if (link->ops->show_fdinfo) + link->ops->show_fdinfo(link, m); +} +#endif + +static __poll_t bpf_link_poll(struct file *file, struct poll_table_struct *pts) +{ + struct bpf_link *link = file->private_data; + + return link->ops->poll(file, pts); +} + +static const struct file_operations bpf_link_fops = { +#ifdef CONFIG_PROC_FS + .show_fdinfo = bpf_link_show_fdinfo, +#endif + .release = bpf_link_release, .read = bpf_dummy_read, .write = bpf_dummy_write, }; -#define BPF_RAW_TRACEPOINT_OPEN_LAST_FIELD raw_tracepoint.prog_fd +static const struct file_operations bpf_link_fops_poll = { +#ifdef CONFIG_PROC_FS + .show_fdinfo = bpf_link_show_fdinfo, +#endif + .release = bpf_link_release, + .read = bpf_dummy_read, + .write = bpf_dummy_write, + .poll = bpf_link_poll, +}; -static int bpf_raw_tracepoint_open(const union bpf_attr *attr) +static int bpf_link_alloc_id(struct bpf_link *link) { - struct bpf_raw_tracepoint *raw_tp; - struct bpf_raw_event_map *btp; - struct bpf_prog *prog; - char tp_name[128]; - int tp_fd, err; + int id; - if (strncpy_from_user(tp_name, u64_to_user_ptr(attr->raw_tracepoint.name), - sizeof(tp_name) - 1) < 0) - return -EFAULT; - tp_name[sizeof(tp_name) - 1] = 0; + idr_preload(GFP_KERNEL); + spin_lock_bh(&link_idr_lock); + id = idr_alloc_cyclic(&link_idr, link, 1, INT_MAX, GFP_ATOMIC); + spin_unlock_bh(&link_idr_lock); + idr_preload_end(); - btp = bpf_get_raw_tracepoint(tp_name); - if (!btp) - return -ENOENT; + return id; +} - raw_tp = kzalloc(sizeof(*raw_tp), GFP_USER); - if (!raw_tp) { - err = -ENOMEM; - goto out_put_btp; +/* Prepare bpf_link to be exposed to user-space by allocating anon_inode file, + * reserving unused FD and allocating ID from link_idr. This is to be paired + * with bpf_link_settle() to install FD and ID and expose bpf_link to + * user-space, if bpf_link is successfully attached. If not, bpf_link and + * pre-allocated resources are to be freed with bpf_cleanup() call. All the + * transient state is passed around in struct bpf_link_primer. + * This is preferred way to create and initialize bpf_link, especially when + * there are complicated and expensive operations in between creating bpf_link + * itself and attaching it to BPF hook. By using bpf_link_prime() and + * bpf_link_settle() kernel code using bpf_link doesn't have to perform + * expensive (and potentially failing) roll back operations in a rare case + * that file, FD, or ID can't be allocated. + */ +int bpf_link_prime(struct bpf_link *link, struct bpf_link_primer *primer) +{ + struct file *file; + int fd, id; + + fd = get_unused_fd_flags(O_CLOEXEC); + if (fd < 0) + return fd; + + + id = bpf_link_alloc_id(link); + if (id < 0) { + put_unused_fd(fd); + return id; } - raw_tp->btp = btp; - prog = bpf_prog_get_type(attr->raw_tracepoint.prog_fd, - BPF_PROG_TYPE_RAW_TRACEPOINT); - if (IS_ERR(prog)) { - err = PTR_ERR(prog); - goto out_free_tp; + file = anon_inode_getfile("bpf_link", + link->ops->poll ? &bpf_link_fops_poll : &bpf_link_fops, + link, O_CLOEXEC); + if (IS_ERR(file)) { + bpf_link_free_id(id); + put_unused_fd(fd); + return PTR_ERR(file); } - err = bpf_probe_register(raw_tp->btp, prog); - if (err) + primer->link = link; + primer->file = file; + primer->fd = fd; + primer->id = id; + return 0; +} + +int bpf_link_settle(struct bpf_link_primer *primer) +{ + /* make bpf_link fetchable by ID */ + spin_lock_bh(&link_idr_lock); + primer->link->id = primer->id; + spin_unlock_bh(&link_idr_lock); + /* make bpf_link fetchable by FD */ + fd_install(primer->fd, primer->file); + /* pass through installed FD */ + return primer->fd; +} + +int bpf_link_new_fd(struct bpf_link *link) +{ + return anon_inode_getfd("bpf-link", + link->ops->poll ? &bpf_link_fops_poll : &bpf_link_fops, + link, O_CLOEXEC); +} + +struct bpf_link *bpf_link_get_from_fd(u32 ufd) +{ + CLASS(fd, f)(ufd); + struct bpf_link *link; + + if (fd_empty(f)) + return ERR_PTR(-EBADF); + if (fd_file(f)->f_op != &bpf_link_fops && fd_file(f)->f_op != &bpf_link_fops_poll) + return ERR_PTR(-EINVAL); + + link = fd_file(f)->private_data; + bpf_link_inc(link); + return link; +} +EXPORT_SYMBOL_NS(bpf_link_get_from_fd, "BPF_INTERNAL"); + +static void bpf_tracing_link_release(struct bpf_link *link) +{ + struct bpf_tracing_link *tr_link = + container_of(link, struct bpf_tracing_link, link.link); + + WARN_ON_ONCE(bpf_trampoline_unlink_prog(&tr_link->link, + tr_link->trampoline, + tr_link->tgt_prog)); + + bpf_trampoline_put(tr_link->trampoline); + + /* tgt_prog is NULL if target is a kernel function */ + if (tr_link->tgt_prog) + bpf_prog_put(tr_link->tgt_prog); +} + +static void bpf_tracing_link_dealloc(struct bpf_link *link) +{ + struct bpf_tracing_link *tr_link = + container_of(link, struct bpf_tracing_link, link.link); + + kfree(tr_link); +} + +static void bpf_tracing_link_show_fdinfo(const struct bpf_link *link, + struct seq_file *seq) +{ + struct bpf_tracing_link *tr_link = + container_of(link, struct bpf_tracing_link, link.link); + u32 target_btf_id, target_obj_id; + + bpf_trampoline_unpack_key(tr_link->trampoline->key, + &target_obj_id, &target_btf_id); + seq_printf(seq, + "attach_type:\t%d\n" + "target_obj_id:\t%u\n" + "target_btf_id:\t%u\n" + "cookie:\t%llu\n", + link->attach_type, + target_obj_id, + target_btf_id, + tr_link->link.cookie); +} + +static int bpf_tracing_link_fill_link_info(const struct bpf_link *link, + struct bpf_link_info *info) +{ + struct bpf_tracing_link *tr_link = + container_of(link, struct bpf_tracing_link, link.link); + + info->tracing.attach_type = link->attach_type; + info->tracing.cookie = tr_link->link.cookie; + bpf_trampoline_unpack_key(tr_link->trampoline->key, + &info->tracing.target_obj_id, + &info->tracing.target_btf_id); + + return 0; +} + +static const struct bpf_link_ops bpf_tracing_link_lops = { + .release = bpf_tracing_link_release, + .dealloc = bpf_tracing_link_dealloc, + .show_fdinfo = bpf_tracing_link_show_fdinfo, + .fill_link_info = bpf_tracing_link_fill_link_info, +}; + +static int bpf_tracing_prog_attach(struct bpf_prog *prog, + int tgt_prog_fd, + u32 btf_id, + u64 bpf_cookie, + enum bpf_attach_type attach_type) +{ + struct bpf_link_primer link_primer; + struct bpf_prog *tgt_prog = NULL; + struct bpf_trampoline *tr = NULL; + struct bpf_tracing_link *link; + u64 key = 0; + int err; + + switch (prog->type) { + case BPF_PROG_TYPE_TRACING: + if (prog->expected_attach_type != BPF_TRACE_FENTRY && + prog->expected_attach_type != BPF_TRACE_FEXIT && + prog->expected_attach_type != BPF_MODIFY_RETURN) { + err = -EINVAL; + goto out_put_prog; + } + break; + case BPF_PROG_TYPE_EXT: + if (prog->expected_attach_type != 0) { + err = -EINVAL; + goto out_put_prog; + } + break; + case BPF_PROG_TYPE_LSM: + if (prog->expected_attach_type != BPF_LSM_MAC) { + err = -EINVAL; + goto out_put_prog; + } + break; + default: + err = -EINVAL; goto out_put_prog; + } - raw_tp->prog = prog; - tp_fd = anon_inode_getfd("bpf-raw-tracepoint", &bpf_raw_tp_fops, raw_tp, - O_CLOEXEC); - if (tp_fd < 0) { - bpf_probe_unregister(raw_tp->btp, prog); - err = tp_fd; + if (!!tgt_prog_fd != !!btf_id) { + err = -EINVAL; goto out_put_prog; } - return tp_fd; + if (tgt_prog_fd) { + /* + * For now we only allow new targets for BPF_PROG_TYPE_EXT. If this + * part would be changed to implement the same for + * BPF_PROG_TYPE_TRACING, do not forget to update the way how + * attach_tracing_prog flag is set. + */ + if (prog->type != BPF_PROG_TYPE_EXT) { + err = -EINVAL; + goto out_put_prog; + } + + tgt_prog = bpf_prog_get(tgt_prog_fd); + if (IS_ERR(tgt_prog)) { + err = PTR_ERR(tgt_prog); + tgt_prog = NULL; + goto out_put_prog; + } + + key = bpf_trampoline_compute_key(tgt_prog, NULL, btf_id); + } + + link = kzalloc(sizeof(*link), GFP_USER); + if (!link) { + err = -ENOMEM; + goto out_put_prog; + } + bpf_link_init(&link->link.link, BPF_LINK_TYPE_TRACING, + &bpf_tracing_link_lops, prog, attach_type); + + link->link.cookie = bpf_cookie; + + mutex_lock(&prog->aux->dst_mutex); + + /* There are a few possible cases here: + * + * - if prog->aux->dst_trampoline is set, the program was just loaded + * and not yet attached to anything, so we can use the values stored + * in prog->aux + * + * - if prog->aux->dst_trampoline is NULL, the program has already been + * attached to a target and its initial target was cleared (below) + * + * - if tgt_prog != NULL, the caller specified tgt_prog_fd + + * target_btf_id using the link_create API. + * + * - if tgt_prog == NULL when this function was called using the old + * raw_tracepoint_open API, and we need a target from prog->aux + * + * - if prog->aux->dst_trampoline and tgt_prog is NULL, the program + * was detached and is going for re-attachment. + * + * - if prog->aux->dst_trampoline is NULL and tgt_prog and prog->aux->attach_btf + * are NULL, then program was already attached and user did not provide + * tgt_prog_fd so we have no way to find out or create trampoline + */ + if (!prog->aux->dst_trampoline && !tgt_prog) { + /* + * Allow re-attach for TRACING and LSM programs. If it's + * currently linked, bpf_trampoline_link_prog will fail. + * EXT programs need to specify tgt_prog_fd, so they + * re-attach in separate code path. + */ + if (prog->type != BPF_PROG_TYPE_TRACING && + prog->type != BPF_PROG_TYPE_LSM) { + err = -EINVAL; + goto out_unlock; + } + /* We can allow re-attach only if we have valid attach_btf. */ + if (!prog->aux->attach_btf) { + err = -EINVAL; + goto out_unlock; + } + btf_id = prog->aux->attach_btf_id; + key = bpf_trampoline_compute_key(NULL, prog->aux->attach_btf, btf_id); + } + + if (!prog->aux->dst_trampoline || + (key && key != prog->aux->dst_trampoline->key)) { + /* If there is no saved target, or the specified target is + * different from the destination specified at load time, we + * need a new trampoline and a check for compatibility + */ + struct bpf_attach_target_info tgt_info = {}; + + err = bpf_check_attach_target(NULL, prog, tgt_prog, btf_id, + &tgt_info); + if (err) + goto out_unlock; + + if (tgt_info.tgt_mod) { + module_put(prog->aux->mod); + prog->aux->mod = tgt_info.tgt_mod; + } + + tr = bpf_trampoline_get(key, &tgt_info); + if (!tr) { + err = -ENOMEM; + goto out_unlock; + } + } else { + /* The caller didn't specify a target, or the target was the + * same as the destination supplied during program load. This + * means we can reuse the trampoline and reference from program + * load time, and there is no need to allocate a new one. This + * can only happen once for any program, as the saved values in + * prog->aux are cleared below. + */ + tr = prog->aux->dst_trampoline; + tgt_prog = prog->aux->dst_prog; + } + + err = bpf_link_prime(&link->link.link, &link_primer); + if (err) + goto out_unlock; + + err = bpf_trampoline_link_prog(&link->link, tr, tgt_prog); + if (err) { + bpf_link_cleanup(&link_primer); + link = NULL; + goto out_unlock; + } + + link->tgt_prog = tgt_prog; + link->trampoline = tr; + + /* Always clear the trampoline and target prog from prog->aux to make + * sure the original attach destination is not kept alive after a + * program is (re-)attached to another target. + */ + if (prog->aux->dst_prog && + (tgt_prog_fd || tr != prog->aux->dst_trampoline)) + /* got extra prog ref from syscall, or attaching to different prog */ + bpf_prog_put(prog->aux->dst_prog); + if (prog->aux->dst_trampoline && tr != prog->aux->dst_trampoline) + /* we allocated a new trampoline, so free the old one */ + bpf_trampoline_put(prog->aux->dst_trampoline); + + prog->aux->dst_prog = NULL; + prog->aux->dst_trampoline = NULL; + mutex_unlock(&prog->aux->dst_mutex); + + return bpf_link_settle(&link_primer); +out_unlock: + if (tr && tr != prog->aux->dst_trampoline) + bpf_trampoline_put(tr); + mutex_unlock(&prog->aux->dst_mutex); + kfree(link); out_put_prog: - bpf_prog_put(prog); -out_free_tp: - kfree(raw_tp); -out_put_btp: - bpf_put_raw_tracepoint(btp); + if (tgt_prog_fd && tgt_prog) + bpf_prog_put(tgt_prog); return err; } -static int bpf_prog_attach_check_attach_type(const struct bpf_prog *prog, - enum bpf_attach_type attach_type) +static void bpf_raw_tp_link_release(struct bpf_link *link) { - switch (prog->type) { - case BPF_PROG_TYPE_CGROUP_SOCK: - case BPF_PROG_TYPE_CGROUP_SOCK_ADDR: - return attach_type == prog->expected_attach_type ? 0 : -EINVAL; - default: + struct bpf_raw_tp_link *raw_tp = + container_of(link, struct bpf_raw_tp_link, link); + + bpf_probe_unregister(raw_tp->btp, raw_tp); + bpf_put_raw_tracepoint(raw_tp->btp); +} + +static void bpf_raw_tp_link_dealloc(struct bpf_link *link) +{ + struct bpf_raw_tp_link *raw_tp = + container_of(link, struct bpf_raw_tp_link, link); + + kfree(raw_tp); +} + +static void bpf_raw_tp_link_show_fdinfo(const struct bpf_link *link, + struct seq_file *seq) +{ + struct bpf_raw_tp_link *raw_tp_link = + container_of(link, struct bpf_raw_tp_link, link); + + seq_printf(seq, + "tp_name:\t%s\n" + "cookie:\t%llu\n", + raw_tp_link->btp->tp->name, + raw_tp_link->cookie); +} + +static int bpf_copy_to_user(char __user *ubuf, const char *buf, u32 ulen, + u32 len) +{ + if (ulen >= len + 1) { + if (copy_to_user(ubuf, buf, len + 1)) + return -EFAULT; + } else { + char zero = '\0'; + + if (copy_to_user(ubuf, buf, ulen - 1)) + return -EFAULT; + if (put_user(zero, ubuf + ulen - 1)) + return -EFAULT; + return -ENOSPC; + } + + return 0; +} + +static int bpf_raw_tp_link_fill_link_info(const struct bpf_link *link, + struct bpf_link_info *info) +{ + struct bpf_raw_tp_link *raw_tp_link = + container_of(link, struct bpf_raw_tp_link, link); + char __user *ubuf = u64_to_user_ptr(info->raw_tracepoint.tp_name); + const char *tp_name = raw_tp_link->btp->tp->name; + u32 ulen = info->raw_tracepoint.tp_name_len; + size_t tp_len = strlen(tp_name); + + if (!ulen ^ !ubuf) + return -EINVAL; + + info->raw_tracepoint.tp_name_len = tp_len + 1; + info->raw_tracepoint.cookie = raw_tp_link->cookie; + + if (!ubuf) return 0; + + return bpf_copy_to_user(ubuf, tp_name, ulen, tp_len); +} + +static const struct bpf_link_ops bpf_raw_tp_link_lops = { + .release = bpf_raw_tp_link_release, + .dealloc_deferred = bpf_raw_tp_link_dealloc, + .show_fdinfo = bpf_raw_tp_link_show_fdinfo, + .fill_link_info = bpf_raw_tp_link_fill_link_info, +}; + +#ifdef CONFIG_PERF_EVENTS +struct bpf_perf_link { + struct bpf_link link; + struct file *perf_file; +}; + +static void bpf_perf_link_release(struct bpf_link *link) +{ + struct bpf_perf_link *perf_link = container_of(link, struct bpf_perf_link, link); + struct perf_event *event = perf_link->perf_file->private_data; + + perf_event_free_bpf_prog(event); + fput(perf_link->perf_file); +} + +static void bpf_perf_link_dealloc(struct bpf_link *link) +{ + struct bpf_perf_link *perf_link = container_of(link, struct bpf_perf_link, link); + + kfree(perf_link); +} + +static int bpf_perf_link_fill_common(const struct perf_event *event, + char __user *uname, u32 *ulenp, + u64 *probe_offset, u64 *probe_addr, + u32 *fd_type, unsigned long *missed) +{ + const char *buf; + u32 prog_id, ulen; + size_t len; + int err; + + ulen = *ulenp; + if (!ulen ^ !uname) + return -EINVAL; + + err = bpf_get_perf_event_info(event, &prog_id, fd_type, &buf, + probe_offset, probe_addr, missed); + if (err) + return err; + + if (buf) { + len = strlen(buf); + *ulenp = len + 1; + } else { + *ulenp = 1; } + if (!uname) + return 0; + + if (buf) { + err = bpf_copy_to_user(uname, buf, ulen, len); + if (err) + return err; + } else { + char zero = '\0'; + + if (put_user(zero, uname)) + return -EFAULT; + } + return 0; } -#define BPF_PROG_ATTACH_LAST_FIELD attach_flags +#ifdef CONFIG_KPROBE_EVENTS +static int bpf_perf_link_fill_kprobe(const struct perf_event *event, + struct bpf_link_info *info) +{ + unsigned long missed; + char __user *uname; + u64 addr, offset; + u32 ulen, type; + int err; -#define BPF_F_ATTACH_MASK \ - (BPF_F_ALLOW_OVERRIDE | BPF_F_ALLOW_MULTI) + uname = u64_to_user_ptr(info->perf_event.kprobe.func_name); + ulen = info->perf_event.kprobe.name_len; + err = bpf_perf_link_fill_common(event, uname, &ulen, &offset, &addr, + &type, &missed); + if (err) + return err; + if (type == BPF_FD_TYPE_KRETPROBE) + info->perf_event.type = BPF_PERF_EVENT_KRETPROBE; + else + info->perf_event.type = BPF_PERF_EVENT_KPROBE; + info->perf_event.kprobe.name_len = ulen; + info->perf_event.kprobe.offset = offset; + info->perf_event.kprobe.missed = missed; + if (!kallsyms_show_value(current_cred())) + addr = 0; + info->perf_event.kprobe.addr = addr; + info->perf_event.kprobe.cookie = event->bpf_cookie; + return 0; +} -static int bpf_prog_attach(const union bpf_attr *attr) +static void bpf_perf_link_fdinfo_kprobe(const struct perf_event *event, + struct seq_file *seq) { - enum bpf_prog_type ptype; - struct bpf_prog *prog; - int ret; + const char *name; + int err; + u32 prog_id, type; + u64 offset, addr; + unsigned long missed; - if (!capable(CAP_NET_ADMIN)) - return -EPERM; + err = bpf_get_perf_event_info(event, &prog_id, &type, &name, + &offset, &addr, &missed); + if (err) + return; - if (CHECK_ATTR(BPF_PROG_ATTACH)) + seq_printf(seq, + "name:\t%s\n" + "offset:\t%#llx\n" + "missed:\t%lu\n" + "addr:\t%#llx\n" + "event_type:\t%s\n" + "cookie:\t%llu\n", + name, offset, missed, addr, + type == BPF_FD_TYPE_KRETPROBE ? "kretprobe" : "kprobe", + event->bpf_cookie); +} +#endif + +#ifdef CONFIG_UPROBE_EVENTS +static int bpf_perf_link_fill_uprobe(const struct perf_event *event, + struct bpf_link_info *info) +{ + u64 ref_ctr_offset, offset; + char __user *uname; + u32 ulen, type; + int err; + + uname = u64_to_user_ptr(info->perf_event.uprobe.file_name); + ulen = info->perf_event.uprobe.name_len; + err = bpf_perf_link_fill_common(event, uname, &ulen, &offset, &ref_ctr_offset, + &type, NULL); + if (err) + return err; + + if (type == BPF_FD_TYPE_URETPROBE) + info->perf_event.type = BPF_PERF_EVENT_URETPROBE; + else + info->perf_event.type = BPF_PERF_EVENT_UPROBE; + info->perf_event.uprobe.name_len = ulen; + info->perf_event.uprobe.offset = offset; + info->perf_event.uprobe.cookie = event->bpf_cookie; + info->perf_event.uprobe.ref_ctr_offset = ref_ctr_offset; + return 0; +} + +static void bpf_perf_link_fdinfo_uprobe(const struct perf_event *event, + struct seq_file *seq) +{ + const char *name; + int err; + u32 prog_id, type; + u64 offset, ref_ctr_offset; + unsigned long missed; + + err = bpf_get_perf_event_info(event, &prog_id, &type, &name, + &offset, &ref_ctr_offset, &missed); + if (err) + return; + + seq_printf(seq, + "name:\t%s\n" + "offset:\t%#llx\n" + "ref_ctr_offset:\t%#llx\n" + "event_type:\t%s\n" + "cookie:\t%llu\n", + name, offset, ref_ctr_offset, + type == BPF_FD_TYPE_URETPROBE ? "uretprobe" : "uprobe", + event->bpf_cookie); +} +#endif + +static int bpf_perf_link_fill_probe(const struct perf_event *event, + struct bpf_link_info *info) +{ +#ifdef CONFIG_KPROBE_EVENTS + if (event->tp_event->flags & TRACE_EVENT_FL_KPROBE) + return bpf_perf_link_fill_kprobe(event, info); +#endif +#ifdef CONFIG_UPROBE_EVENTS + if (event->tp_event->flags & TRACE_EVENT_FL_UPROBE) + return bpf_perf_link_fill_uprobe(event, info); +#endif + return -EOPNOTSUPP; +} + +static int bpf_perf_link_fill_tracepoint(const struct perf_event *event, + struct bpf_link_info *info) +{ + char __user *uname; + u32 ulen; + int err; + + uname = u64_to_user_ptr(info->perf_event.tracepoint.tp_name); + ulen = info->perf_event.tracepoint.name_len; + err = bpf_perf_link_fill_common(event, uname, &ulen, NULL, NULL, NULL, NULL); + if (err) + return err; + + info->perf_event.type = BPF_PERF_EVENT_TRACEPOINT; + info->perf_event.tracepoint.name_len = ulen; + info->perf_event.tracepoint.cookie = event->bpf_cookie; + return 0; +} + +static int bpf_perf_link_fill_perf_event(const struct perf_event *event, + struct bpf_link_info *info) +{ + info->perf_event.event.type = event->attr.type; + info->perf_event.event.config = event->attr.config; + info->perf_event.event.cookie = event->bpf_cookie; + info->perf_event.type = BPF_PERF_EVENT_EVENT; + return 0; +} + +static int bpf_perf_link_fill_link_info(const struct bpf_link *link, + struct bpf_link_info *info) +{ + struct bpf_perf_link *perf_link; + const struct perf_event *event; + + perf_link = container_of(link, struct bpf_perf_link, link); + event = perf_get_event(perf_link->perf_file); + if (IS_ERR(event)) + return PTR_ERR(event); + + switch (event->prog->type) { + case BPF_PROG_TYPE_PERF_EVENT: + return bpf_perf_link_fill_perf_event(event, info); + case BPF_PROG_TYPE_TRACEPOINT: + return bpf_perf_link_fill_tracepoint(event, info); + case BPF_PROG_TYPE_KPROBE: + return bpf_perf_link_fill_probe(event, info); + default: + return -EOPNOTSUPP; + } +} + +static void bpf_perf_event_link_show_fdinfo(const struct perf_event *event, + struct seq_file *seq) +{ + seq_printf(seq, + "type:\t%u\n" + "config:\t%llu\n" + "event_type:\t%s\n" + "cookie:\t%llu\n", + event->attr.type, event->attr.config, + "event", event->bpf_cookie); +} + +static void bpf_tracepoint_link_show_fdinfo(const struct perf_event *event, + struct seq_file *seq) +{ + int err; + const char *name; + u32 prog_id; + + err = bpf_get_perf_event_info(event, &prog_id, NULL, &name, NULL, + NULL, NULL); + if (err) + return; + + seq_printf(seq, + "tp_name:\t%s\n" + "event_type:\t%s\n" + "cookie:\t%llu\n", + name, "tracepoint", event->bpf_cookie); +} + +static void bpf_probe_link_show_fdinfo(const struct perf_event *event, + struct seq_file *seq) +{ +#ifdef CONFIG_KPROBE_EVENTS + if (event->tp_event->flags & TRACE_EVENT_FL_KPROBE) + return bpf_perf_link_fdinfo_kprobe(event, seq); +#endif + +#ifdef CONFIG_UPROBE_EVENTS + if (event->tp_event->flags & TRACE_EVENT_FL_UPROBE) + return bpf_perf_link_fdinfo_uprobe(event, seq); +#endif +} + +static void bpf_perf_link_show_fdinfo(const struct bpf_link *link, + struct seq_file *seq) +{ + struct bpf_perf_link *perf_link; + const struct perf_event *event; + + perf_link = container_of(link, struct bpf_perf_link, link); + event = perf_get_event(perf_link->perf_file); + if (IS_ERR(event)) + return; + + switch (event->prog->type) { + case BPF_PROG_TYPE_PERF_EVENT: + return bpf_perf_event_link_show_fdinfo(event, seq); + case BPF_PROG_TYPE_TRACEPOINT: + return bpf_tracepoint_link_show_fdinfo(event, seq); + case BPF_PROG_TYPE_KPROBE: + return bpf_probe_link_show_fdinfo(event, seq); + default: + return; + } +} + +static const struct bpf_link_ops bpf_perf_link_lops = { + .release = bpf_perf_link_release, + .dealloc = bpf_perf_link_dealloc, + .fill_link_info = bpf_perf_link_fill_link_info, + .show_fdinfo = bpf_perf_link_show_fdinfo, +}; + +static int bpf_perf_link_attach(const union bpf_attr *attr, struct bpf_prog *prog) +{ + struct bpf_link_primer link_primer; + struct bpf_perf_link *link; + struct perf_event *event; + struct file *perf_file; + int err; + + if (attr->link_create.flags) return -EINVAL; - if (attr->attach_flags & ~BPF_F_ATTACH_MASK) + perf_file = perf_event_get(attr->link_create.target_fd); + if (IS_ERR(perf_file)) + return PTR_ERR(perf_file); + + link = kzalloc(sizeof(*link), GFP_USER); + if (!link) { + err = -ENOMEM; + goto out_put_file; + } + bpf_link_init(&link->link, BPF_LINK_TYPE_PERF_EVENT, &bpf_perf_link_lops, prog, + attr->link_create.attach_type); + link->perf_file = perf_file; + + err = bpf_link_prime(&link->link, &link_primer); + if (err) { + kfree(link); + goto out_put_file; + } + + event = perf_file->private_data; + err = perf_event_set_bpf_prog(event, prog, attr->link_create.perf_event.bpf_cookie); + if (err) { + bpf_link_cleanup(&link_primer); + goto out_put_file; + } + /* perf_event_set_bpf_prog() doesn't take its own refcnt on prog */ + bpf_prog_inc(prog); + + return bpf_link_settle(&link_primer); + +out_put_file: + fput(perf_file); + return err; +} +#else +static int bpf_perf_link_attach(const union bpf_attr *attr, struct bpf_prog *prog) +{ + return -EOPNOTSUPP; +} +#endif /* CONFIG_PERF_EVENTS */ + +static int bpf_raw_tp_link_attach(struct bpf_prog *prog, + const char __user *user_tp_name, u64 cookie, + enum bpf_attach_type attach_type) +{ + struct bpf_link_primer link_primer; + struct bpf_raw_tp_link *link; + struct bpf_raw_event_map *btp; + const char *tp_name; + char buf[128]; + int err; + + switch (prog->type) { + case BPF_PROG_TYPE_TRACING: + case BPF_PROG_TYPE_EXT: + case BPF_PROG_TYPE_LSM: + if (user_tp_name) + /* The attach point for this category of programs + * should be specified via btf_id during program load. + */ + return -EINVAL; + if (prog->type == BPF_PROG_TYPE_TRACING && + prog->expected_attach_type == BPF_TRACE_RAW_TP) { + tp_name = prog->aux->attach_func_name; + break; + } + return bpf_tracing_prog_attach(prog, 0, 0, 0, attach_type); + case BPF_PROG_TYPE_RAW_TRACEPOINT: + case BPF_PROG_TYPE_RAW_TRACEPOINT_WRITABLE: + if (strncpy_from_user(buf, user_tp_name, sizeof(buf) - 1) < 0) + return -EFAULT; + buf[sizeof(buf) - 1] = 0; + tp_name = buf; + break; + default: return -EINVAL; + } + + btp = bpf_get_raw_tracepoint(tp_name); + if (!btp) + return -ENOENT; + + link = kzalloc(sizeof(*link), GFP_USER); + if (!link) { + err = -ENOMEM; + goto out_put_btp; + } + bpf_link_init_sleepable(&link->link, BPF_LINK_TYPE_RAW_TRACEPOINT, + &bpf_raw_tp_link_lops, prog, attach_type, + tracepoint_is_faultable(btp->tp)); + link->btp = btp; + link->cookie = cookie; + + err = bpf_link_prime(&link->link, &link_primer); + if (err) { + kfree(link); + goto out_put_btp; + } + + err = bpf_probe_register(link->btp, link); + if (err) { + bpf_link_cleanup(&link_primer); + goto out_put_btp; + } + + return bpf_link_settle(&link_primer); + +out_put_btp: + bpf_put_raw_tracepoint(btp); + return err; +} + +#define BPF_RAW_TRACEPOINT_OPEN_LAST_FIELD raw_tracepoint.cookie + +static int bpf_raw_tracepoint_open(const union bpf_attr *attr) +{ + struct bpf_prog *prog; + void __user *tp_name; + __u64 cookie; + int fd; + + if (CHECK_ATTR(BPF_RAW_TRACEPOINT_OPEN)) + return -EINVAL; + + prog = bpf_prog_get(attr->raw_tracepoint.prog_fd); + if (IS_ERR(prog)) + return PTR_ERR(prog); + + tp_name = u64_to_user_ptr(attr->raw_tracepoint.name); + cookie = attr->raw_tracepoint.cookie; + fd = bpf_raw_tp_link_attach(prog, tp_name, cookie, prog->expected_attach_type); + if (fd < 0) + bpf_prog_put(prog); + return fd; +} - switch (attr->attach_type) { +static enum bpf_prog_type +attach_type_to_prog_type(enum bpf_attach_type attach_type) +{ + switch (attach_type) { case BPF_CGROUP_INET_INGRESS: case BPF_CGROUP_INET_EGRESS: - ptype = BPF_PROG_TYPE_CGROUP_SKB; - break; + return BPF_PROG_TYPE_CGROUP_SKB; case BPF_CGROUP_INET_SOCK_CREATE: + case BPF_CGROUP_INET_SOCK_RELEASE: case BPF_CGROUP_INET4_POST_BIND: case BPF_CGROUP_INET6_POST_BIND: - ptype = BPF_PROG_TYPE_CGROUP_SOCK; - break; + return BPF_PROG_TYPE_CGROUP_SOCK; case BPF_CGROUP_INET4_BIND: case BPF_CGROUP_INET6_BIND: case BPF_CGROUP_INET4_CONNECT: case BPF_CGROUP_INET6_CONNECT: + case BPF_CGROUP_UNIX_CONNECT: + case BPF_CGROUP_INET4_GETPEERNAME: + case BPF_CGROUP_INET6_GETPEERNAME: + case BPF_CGROUP_UNIX_GETPEERNAME: + case BPF_CGROUP_INET4_GETSOCKNAME: + case BPF_CGROUP_INET6_GETSOCKNAME: + case BPF_CGROUP_UNIX_GETSOCKNAME: case BPF_CGROUP_UDP4_SENDMSG: case BPF_CGROUP_UDP6_SENDMSG: - ptype = BPF_PROG_TYPE_CGROUP_SOCK_ADDR; - break; + case BPF_CGROUP_UNIX_SENDMSG: + case BPF_CGROUP_UDP4_RECVMSG: + case BPF_CGROUP_UDP6_RECVMSG: + case BPF_CGROUP_UNIX_RECVMSG: + return BPF_PROG_TYPE_CGROUP_SOCK_ADDR; case BPF_CGROUP_SOCK_OPS: - ptype = BPF_PROG_TYPE_SOCK_OPS; - break; + return BPF_PROG_TYPE_SOCK_OPS; case BPF_CGROUP_DEVICE: - ptype = BPF_PROG_TYPE_CGROUP_DEVICE; - break; + return BPF_PROG_TYPE_CGROUP_DEVICE; case BPF_SK_MSG_VERDICT: - ptype = BPF_PROG_TYPE_SK_MSG; - break; + return BPF_PROG_TYPE_SK_MSG; case BPF_SK_SKB_STREAM_PARSER: case BPF_SK_SKB_STREAM_VERDICT: - ptype = BPF_PROG_TYPE_SK_SKB; - break; + case BPF_SK_SKB_VERDICT: + return BPF_PROG_TYPE_SK_SKB; case BPF_LIRC_MODE2: - ptype = BPF_PROG_TYPE_LIRC_MODE2; - break; + return BPF_PROG_TYPE_LIRC_MODE2; case BPF_FLOW_DISSECTOR: - ptype = BPF_PROG_TYPE_FLOW_DISSECTOR; - break; + return BPF_PROG_TYPE_FLOW_DISSECTOR; + case BPF_CGROUP_SYSCTL: + return BPF_PROG_TYPE_CGROUP_SYSCTL; + case BPF_CGROUP_GETSOCKOPT: + case BPF_CGROUP_SETSOCKOPT: + return BPF_PROG_TYPE_CGROUP_SOCKOPT; + case BPF_TRACE_ITER: + case BPF_TRACE_RAW_TP: + case BPF_TRACE_FENTRY: + case BPF_TRACE_FEXIT: + case BPF_MODIFY_RETURN: + return BPF_PROG_TYPE_TRACING; + case BPF_LSM_MAC: + return BPF_PROG_TYPE_LSM; + case BPF_SK_LOOKUP: + return BPF_PROG_TYPE_SK_LOOKUP; + case BPF_XDP: + return BPF_PROG_TYPE_XDP; + case BPF_LSM_CGROUP: + return BPF_PROG_TYPE_LSM; + case BPF_TCX_INGRESS: + case BPF_TCX_EGRESS: + case BPF_NETKIT_PRIMARY: + case BPF_NETKIT_PEER: + return BPF_PROG_TYPE_SCHED_CLS; + default: + return BPF_PROG_TYPE_UNSPEC; + } +} + +static int bpf_prog_attach_check_attach_type(const struct bpf_prog *prog, + enum bpf_attach_type attach_type) +{ + enum bpf_prog_type ptype; + + switch (prog->type) { + case BPF_PROG_TYPE_CGROUP_SOCK: + case BPF_PROG_TYPE_CGROUP_SOCK_ADDR: + case BPF_PROG_TYPE_CGROUP_SOCKOPT: + case BPF_PROG_TYPE_SK_LOOKUP: + return attach_type == prog->expected_attach_type ? 0 : -EINVAL; + case BPF_PROG_TYPE_CGROUP_SKB: + if (!bpf_token_capable(prog->aux->token, CAP_NET_ADMIN)) + /* cg-skb progs can be loaded by unpriv user. + * check permissions at attach time. + */ + return -EPERM; + + ptype = attach_type_to_prog_type(attach_type); + if (prog->type != ptype) + return -EINVAL; + + return prog->enforce_expected_attach_type && + prog->expected_attach_type != attach_type ? + -EINVAL : 0; + case BPF_PROG_TYPE_EXT: + return 0; + case BPF_PROG_TYPE_NETFILTER: + if (attach_type != BPF_NETFILTER) + return -EINVAL; + return 0; + case BPF_PROG_TYPE_PERF_EVENT: + case BPF_PROG_TYPE_TRACEPOINT: + if (attach_type != BPF_PERF_EVENT) + return -EINVAL; + return 0; + case BPF_PROG_TYPE_KPROBE: + if (prog->expected_attach_type == BPF_TRACE_KPROBE_MULTI && + attach_type != BPF_TRACE_KPROBE_MULTI) + return -EINVAL; + if (prog->expected_attach_type == BPF_TRACE_KPROBE_SESSION && + attach_type != BPF_TRACE_KPROBE_SESSION) + return -EINVAL; + if (prog->expected_attach_type == BPF_TRACE_UPROBE_MULTI && + attach_type != BPF_TRACE_UPROBE_MULTI) + return -EINVAL; + if (prog->expected_attach_type == BPF_TRACE_UPROBE_SESSION && + attach_type != BPF_TRACE_UPROBE_SESSION) + return -EINVAL; + if (attach_type != BPF_PERF_EVENT && + attach_type != BPF_TRACE_KPROBE_MULTI && + attach_type != BPF_TRACE_KPROBE_SESSION && + attach_type != BPF_TRACE_UPROBE_MULTI && + attach_type != BPF_TRACE_UPROBE_SESSION) + return -EINVAL; + return 0; + case BPF_PROG_TYPE_SCHED_CLS: + if (attach_type != BPF_TCX_INGRESS && + attach_type != BPF_TCX_EGRESS && + attach_type != BPF_NETKIT_PRIMARY && + attach_type != BPF_NETKIT_PEER) + return -EINVAL; + return 0; default: + ptype = attach_type_to_prog_type(attach_type); + if (ptype == BPF_PROG_TYPE_UNSPEC || ptype != prog->type) + return -EINVAL; + return 0; + } +} + +static bool is_cgroup_prog_type(enum bpf_prog_type ptype, enum bpf_attach_type atype, + bool check_atype) +{ + switch (ptype) { + case BPF_PROG_TYPE_CGROUP_DEVICE: + case BPF_PROG_TYPE_CGROUP_SKB: + case BPF_PROG_TYPE_CGROUP_SOCK: + case BPF_PROG_TYPE_CGROUP_SOCK_ADDR: + case BPF_PROG_TYPE_CGROUP_SOCKOPT: + case BPF_PROG_TYPE_CGROUP_SYSCTL: + case BPF_PROG_TYPE_SOCK_OPS: + return true; + case BPF_PROG_TYPE_LSM: + return check_atype ? atype == BPF_LSM_CGROUP : true; + default: + return false; + } +} + +#define BPF_PROG_ATTACH_LAST_FIELD expected_revision + +#define BPF_F_ATTACH_MASK_BASE \ + (BPF_F_ALLOW_OVERRIDE | \ + BPF_F_ALLOW_MULTI | \ + BPF_F_REPLACE | \ + BPF_F_PREORDER) + +#define BPF_F_ATTACH_MASK_MPROG \ + (BPF_F_REPLACE | \ + BPF_F_BEFORE | \ + BPF_F_AFTER | \ + BPF_F_ID | \ + BPF_F_LINK) + +static int bpf_prog_attach(const union bpf_attr *attr) +{ + enum bpf_prog_type ptype; + struct bpf_prog *prog; + int ret; + + if (CHECK_ATTR(BPF_PROG_ATTACH)) return -EINVAL; + + ptype = attach_type_to_prog_type(attr->attach_type); + if (ptype == BPF_PROG_TYPE_UNSPEC) + return -EINVAL; + if (bpf_mprog_supported(ptype)) { + if (attr->attach_flags & ~BPF_F_ATTACH_MASK_MPROG) + return -EINVAL; + } else if (is_cgroup_prog_type(ptype, 0, false)) { + if (attr->attach_flags & ~(BPF_F_ATTACH_MASK_BASE | BPF_F_ATTACH_MASK_MPROG)) + return -EINVAL; + } else { + if (attr->attach_flags & ~BPF_F_ATTACH_MASK_BASE) + return -EINVAL; + if (attr->relative_fd || + attr->expected_revision) + return -EINVAL; } prog = bpf_prog_get_type(attr->attach_bpf_fd, ptype); @@ -1753,6 +4512,11 @@ static int bpf_prog_attach(const union bpf_attr *attr) return -EINVAL; } + if (is_cgroup_prog_type(ptype, prog->expected_attach_type, true)) { + ret = cgroup_bpf_prog_attach(attr, ptype, prog); + goto out; + } + switch (ptype) { case BPF_PROG_TYPE_SK_SKB: case BPF_PROG_TYPE_SK_MSG: @@ -1762,75 +4526,98 @@ static int bpf_prog_attach(const union bpf_attr *attr) ret = lirc_prog_attach(attr, prog); break; case BPF_PROG_TYPE_FLOW_DISSECTOR: - ret = skb_flow_dissector_bpf_prog_attach(attr, prog); + ret = netns_bpf_prog_attach(attr, prog); + break; + case BPF_PROG_TYPE_SCHED_CLS: + if (attr->attach_type == BPF_TCX_INGRESS || + attr->attach_type == BPF_TCX_EGRESS) + ret = tcx_prog_attach(attr, prog); + else + ret = netkit_prog_attach(attr, prog); break; default: - ret = cgroup_bpf_prog_attach(attr, ptype, prog); + ret = -EINVAL; } - +out: if (ret) bpf_prog_put(prog); return ret; } -#define BPF_PROG_DETACH_LAST_FIELD attach_type +#define BPF_PROG_DETACH_LAST_FIELD expected_revision static int bpf_prog_detach(const union bpf_attr *attr) { + struct bpf_prog *prog = NULL; enum bpf_prog_type ptype; - - if (!capable(CAP_NET_ADMIN)) - return -EPERM; + int ret; if (CHECK_ATTR(BPF_PROG_DETACH)) return -EINVAL; - switch (attr->attach_type) { - case BPF_CGROUP_INET_INGRESS: - case BPF_CGROUP_INET_EGRESS: - ptype = BPF_PROG_TYPE_CGROUP_SKB; + ptype = attach_type_to_prog_type(attr->attach_type); + if (bpf_mprog_supported(ptype)) { + if (ptype == BPF_PROG_TYPE_UNSPEC) + return -EINVAL; + if (attr->attach_flags & ~BPF_F_ATTACH_MASK_MPROG) + return -EINVAL; + if (attr->attach_bpf_fd) { + prog = bpf_prog_get_type(attr->attach_bpf_fd, ptype); + if (IS_ERR(prog)) + return PTR_ERR(prog); + } + } else if (is_cgroup_prog_type(ptype, 0, false)) { + if (attr->attach_flags || attr->relative_fd) + return -EINVAL; + } else if (attr->attach_flags || + attr->relative_fd || + attr->expected_revision) { + return -EINVAL; + } + + switch (ptype) { + case BPF_PROG_TYPE_SK_MSG: + case BPF_PROG_TYPE_SK_SKB: + ret = sock_map_prog_detach(attr, ptype); break; - case BPF_CGROUP_INET_SOCK_CREATE: - case BPF_CGROUP_INET4_POST_BIND: - case BPF_CGROUP_INET6_POST_BIND: - ptype = BPF_PROG_TYPE_CGROUP_SOCK; + case BPF_PROG_TYPE_LIRC_MODE2: + ret = lirc_prog_detach(attr); break; - case BPF_CGROUP_INET4_BIND: - case BPF_CGROUP_INET6_BIND: - case BPF_CGROUP_INET4_CONNECT: - case BPF_CGROUP_INET6_CONNECT: - case BPF_CGROUP_UDP4_SENDMSG: - case BPF_CGROUP_UDP6_SENDMSG: - ptype = BPF_PROG_TYPE_CGROUP_SOCK_ADDR; + case BPF_PROG_TYPE_FLOW_DISSECTOR: + ret = netns_bpf_prog_detach(attr, ptype); break; - case BPF_CGROUP_SOCK_OPS: - ptype = BPF_PROG_TYPE_SOCK_OPS; + case BPF_PROG_TYPE_CGROUP_DEVICE: + case BPF_PROG_TYPE_CGROUP_SKB: + case BPF_PROG_TYPE_CGROUP_SOCK: + case BPF_PROG_TYPE_CGROUP_SOCK_ADDR: + case BPF_PROG_TYPE_CGROUP_SOCKOPT: + case BPF_PROG_TYPE_CGROUP_SYSCTL: + case BPF_PROG_TYPE_SOCK_OPS: + case BPF_PROG_TYPE_LSM: + ret = cgroup_bpf_prog_detach(attr, ptype); break; - case BPF_CGROUP_DEVICE: - ptype = BPF_PROG_TYPE_CGROUP_DEVICE; + case BPF_PROG_TYPE_SCHED_CLS: + if (attr->attach_type == BPF_TCX_INGRESS || + attr->attach_type == BPF_TCX_EGRESS) + ret = tcx_prog_detach(attr, prog); + else + ret = netkit_prog_detach(attr, prog); break; - case BPF_SK_MSG_VERDICT: - return sock_map_get_from_fd(attr, NULL); - case BPF_SK_SKB_STREAM_PARSER: - case BPF_SK_SKB_STREAM_VERDICT: - return sock_map_get_from_fd(attr, NULL); - case BPF_LIRC_MODE2: - return lirc_prog_detach(attr); - case BPF_FLOW_DISSECTOR: - return skb_flow_dissector_bpf_prog_detach(attr); default: - return -EINVAL; + ret = -EINVAL; } - return cgroup_bpf_prog_detach(attr, ptype); + if (prog) + bpf_prog_put(prog); + return ret; } -#define BPF_PROG_QUERY_LAST_FIELD query.prog_cnt +#define BPF_PROG_QUERY_LAST_FIELD query.revision static int bpf_prog_query(const union bpf_attr *attr, union bpf_attr __user *uattr) { - if (!capable(CAP_NET_ADMIN)) + if (!bpf_net_capable()) return -EPERM; if (CHECK_ATTR(BPF_PROG_QUERY)) return -EINVAL; @@ -1841,27 +4628,55 @@ static int bpf_prog_query(const union bpf_attr *attr, case BPF_CGROUP_INET_INGRESS: case BPF_CGROUP_INET_EGRESS: case BPF_CGROUP_INET_SOCK_CREATE: + case BPF_CGROUP_INET_SOCK_RELEASE: case BPF_CGROUP_INET4_BIND: case BPF_CGROUP_INET6_BIND: case BPF_CGROUP_INET4_POST_BIND: case BPF_CGROUP_INET6_POST_BIND: case BPF_CGROUP_INET4_CONNECT: case BPF_CGROUP_INET6_CONNECT: + case BPF_CGROUP_UNIX_CONNECT: + case BPF_CGROUP_INET4_GETPEERNAME: + case BPF_CGROUP_INET6_GETPEERNAME: + case BPF_CGROUP_UNIX_GETPEERNAME: + case BPF_CGROUP_INET4_GETSOCKNAME: + case BPF_CGROUP_INET6_GETSOCKNAME: + case BPF_CGROUP_UNIX_GETSOCKNAME: case BPF_CGROUP_UDP4_SENDMSG: case BPF_CGROUP_UDP6_SENDMSG: + case BPF_CGROUP_UNIX_SENDMSG: + case BPF_CGROUP_UDP4_RECVMSG: + case BPF_CGROUP_UDP6_RECVMSG: + case BPF_CGROUP_UNIX_RECVMSG: case BPF_CGROUP_SOCK_OPS: case BPF_CGROUP_DEVICE: - break; + case BPF_CGROUP_SYSCTL: + case BPF_CGROUP_GETSOCKOPT: + case BPF_CGROUP_SETSOCKOPT: + case BPF_LSM_CGROUP: + return cgroup_bpf_prog_query(attr, uattr); case BPF_LIRC_MODE2: return lirc_prog_query(attr, uattr); + case BPF_FLOW_DISSECTOR: + case BPF_SK_LOOKUP: + return netns_bpf_prog_query(attr, uattr); + case BPF_SK_SKB_STREAM_PARSER: + case BPF_SK_SKB_STREAM_VERDICT: + case BPF_SK_MSG_VERDICT: + case BPF_SK_SKB_VERDICT: + return sock_map_bpf_prog_query(attr, uattr); + case BPF_TCX_INGRESS: + case BPF_TCX_EGRESS: + return tcx_prog_query(attr, uattr); + case BPF_NETKIT_PRIMARY: + case BPF_NETKIT_PEER: + return netkit_prog_query(attr, uattr); default: return -EINVAL; } - - return cgroup_bpf_prog_query(attr, uattr); } -#define BPF_PROG_TEST_RUN_LAST_FIELD test.duration +#define BPF_PROG_TEST_RUN_LAST_FIELD test.batch_size static int bpf_prog_test_run(const union bpf_attr *attr, union bpf_attr __user *uattr) @@ -1869,11 +4684,17 @@ static int bpf_prog_test_run(const union bpf_attr *attr, struct bpf_prog *prog; int ret = -ENOTSUPP; - if (!capable(CAP_SYS_ADMIN)) - return -EPERM; if (CHECK_ATTR(BPF_PROG_TEST_RUN)) return -EINVAL; + if ((attr->test.ctx_size_in && !attr->test.ctx_in) || + (!attr->test.ctx_size_in && attr->test.ctx_in)) + return -EINVAL; + + if ((attr->test.ctx_size_out && !attr->test.ctx_out) || + (!attr->test.ctx_size_out && attr->test.ctx_out)) + return -EINVAL; + prog = bpf_prog_get(attr->test.prog_fd); if (IS_ERR(prog)) return PTR_ERR(prog); @@ -1913,19 +4734,52 @@ static int bpf_obj_get_next_id(const union bpf_attr *attr, return err; } -#define BPF_PROG_GET_FD_BY_ID_LAST_FIELD prog_id +struct bpf_map *bpf_map_get_curr_or_next(u32 *id) +{ + struct bpf_map *map; -static int bpf_prog_get_fd_by_id(const union bpf_attr *attr) + spin_lock_bh(&map_idr_lock); +again: + map = idr_get_next(&map_idr, id); + if (map) { + map = __bpf_map_inc_not_zero(map, false); + if (IS_ERR(map)) { + (*id)++; + goto again; + } + } + spin_unlock_bh(&map_idr_lock); + + return map; +} + +struct bpf_prog *bpf_prog_get_curr_or_next(u32 *id) { struct bpf_prog *prog; - u32 id = attr->prog_id; - int fd; - if (CHECK_ATTR(BPF_PROG_GET_FD_BY_ID)) - return -EINVAL; + spin_lock_bh(&prog_idr_lock); +again: + prog = idr_get_next(&prog_idr, id); + if (prog) { + prog = bpf_prog_inc_not_zero(prog); + if (IS_ERR(prog)) { + (*id)++; + goto again; + } + } + spin_unlock_bh(&prog_idr_lock); - if (!capable(CAP_SYS_ADMIN)) - return -EPERM; + return prog; +} + +#define BPF_PROG_GET_FD_BY_ID_LAST_FIELD prog_id + +struct bpf_prog *bpf_prog_by_id(u32 id) +{ + struct bpf_prog *prog; + + if (!id) + return ERR_PTR(-ENOENT); spin_lock_bh(&prog_idr_lock); prog = idr_find(&prog_idr, id); @@ -1934,7 +4788,22 @@ static int bpf_prog_get_fd_by_id(const union bpf_attr *attr) else prog = ERR_PTR(-ENOENT); spin_unlock_bh(&prog_idr_lock); + return prog; +} +static int bpf_prog_get_fd_by_id(const union bpf_attr *attr) +{ + struct bpf_prog *prog; + u32 id = attr->prog_id; + int fd; + + if (CHECK_ATTR(BPF_PROG_GET_FD_BY_ID)) + return -EINVAL; + + if (!capable(CAP_SYS_ADMIN)) + return -EPERM; + + prog = bpf_prog_by_id(id); if (IS_ERR(prog)) return PTR_ERR(prog); @@ -1968,7 +4837,7 @@ static int bpf_map_get_fd_by_id(const union bpf_attr *attr) spin_lock_bh(&map_idr_lock); map = idr_find(&map_idr, id); if (map) - map = bpf_map_inc_not_zero(map, true); + map = __bpf_map_inc_not_zero(map, true); else map = ERR_PTR(-ENOENT); spin_unlock_bh(&map_idr_lock); @@ -1978,27 +4847,47 @@ static int bpf_map_get_fd_by_id(const union bpf_attr *attr) fd = bpf_map_new_fd(map, f_flags); if (fd < 0) - bpf_map_put(map); + bpf_map_put_with_uref(map); return fd; } static const struct bpf_map *bpf_map_from_imm(const struct bpf_prog *prog, - unsigned long addr) + unsigned long addr, u32 *off, + u32 *type) { + const struct bpf_map *map; int i; - for (i = 0; i < prog->aux->used_map_cnt; i++) - if (prog->aux->used_maps[i] == (void *)addr) - return prog->aux->used_maps[i]; - return NULL; + mutex_lock(&prog->aux->used_maps_mutex); + for (i = 0, *off = 0; i < prog->aux->used_map_cnt; i++) { + map = prog->aux->used_maps[i]; + if (map == (void *)addr) { + *type = BPF_PSEUDO_MAP_FD; + goto out; + } + if (!map->ops->map_direct_value_meta) + continue; + if (!map->ops->map_direct_value_meta(map, addr, off)) { + *type = BPF_PSEUDO_MAP_VALUE; + goto out; + } + } + map = NULL; + +out: + mutex_unlock(&prog->aux->used_maps_mutex); + return map; } -static struct bpf_insn *bpf_insn_prepare_dump(const struct bpf_prog *prog) +static struct bpf_insn *bpf_insn_prepare_dump(const struct bpf_prog *prog, + const struct cred *f_cred) { const struct bpf_map *map; struct bpf_insn *insns; + u32 off, type; u64 imm; + u8 code; int i; insns = kmemdup(prog->insnsi, bpf_prog_insn_size(prog), @@ -2007,29 +4896,41 @@ static struct bpf_insn *bpf_insn_prepare_dump(const struct bpf_prog *prog) return insns; for (i = 0; i < prog->len; i++) { - if (insns[i].code == (BPF_JMP | BPF_TAIL_CALL)) { + code = insns[i].code; + + if (code == (BPF_JMP | BPF_TAIL_CALL)) { insns[i].code = BPF_JMP | BPF_CALL; insns[i].imm = BPF_FUNC_tail_call; /* fall-through */ } - if (insns[i].code == (BPF_JMP | BPF_CALL) || - insns[i].code == (BPF_JMP | BPF_CALL_ARGS)) { - if (insns[i].code == (BPF_JMP | BPF_CALL_ARGS)) + if (code == (BPF_JMP | BPF_CALL) || + code == (BPF_JMP | BPF_CALL_ARGS)) { + if (code == (BPF_JMP | BPF_CALL_ARGS)) insns[i].code = BPF_JMP | BPF_CALL; - if (!bpf_dump_raw_ok()) + if (!bpf_dump_raw_ok(f_cred)) insns[i].imm = 0; continue; } + if (BPF_CLASS(code) == BPF_LDX && BPF_MODE(code) == BPF_PROBE_MEM) { + insns[i].code = BPF_LDX | BPF_SIZE(code) | BPF_MEM; + continue; + } + + if ((BPF_CLASS(code) == BPF_LDX || BPF_CLASS(code) == BPF_STX || + BPF_CLASS(code) == BPF_ST) && BPF_MODE(code) == BPF_PROBE_MEM32) { + insns[i].code = BPF_CLASS(code) | BPF_SIZE(code) | BPF_MEM; + continue; + } - if (insns[i].code != (BPF_LD | BPF_IMM | BPF_DW)) + if (code != (BPF_LD | BPF_IMM | BPF_DW)) continue; imm = ((u64)insns[i + 1].imm << 32) | (u32)insns[i].imm; - map = bpf_map_from_imm(prog, imm); + map = bpf_map_from_imm(prog, imm, &off, &type); if (map) { - insns[i].src_reg = BPF_PSEUDO_MAP_FD; + insns[i].src_reg = type; insns[i].imm = map->id; - insns[i + 1].imm = 0; + insns[i + 1].imm = off; continue; } } @@ -2068,22 +4969,26 @@ static int set_info_rec_size(struct bpf_prog_info *info) return 0; } -static int bpf_prog_get_info_by_fd(struct bpf_prog *prog, +static int bpf_prog_get_info_by_fd(struct file *file, + struct bpf_prog *prog, const union bpf_attr *attr, union bpf_attr __user *uattr) { struct bpf_prog_info __user *uinfo = u64_to_user_ptr(attr->info.info); - struct bpf_prog_info info = {}; + struct btf *attach_btf = bpf_prog_get_target_btf(prog); + struct bpf_prog_info info; u32 info_len = attr->info.info_len; + struct bpf_prog_kstats stats; char __user *uinsns; u32 ulen; int err; - err = bpf_check_uarg_tail_zero(uinfo, sizeof(info), info_len); + err = bpf_check_uarg_tail_zero(USER_BPFPTR(uinfo), sizeof(info), info_len); if (err) return err; info_len = min_t(u32, sizeof(info), info_len); + memset(&info, 0, sizeof(info)); if (copy_from_user(&info, uinfo, info_len)) return -EFAULT; @@ -2097,6 +5002,7 @@ static int bpf_prog_get_info_by_fd(struct bpf_prog *prog, memcpy(info.tag, prog->tag, sizeof(prog->tag)); memcpy(info.name, prog->aux->name, sizeof(prog->aux->name)); + mutex_lock(&prog->aux->used_maps_mutex); ulen = info.nr_map_ids; info.nr_map_ids = prog->aux->used_map_cnt; ulen = min_t(u32, info.nr_map_ids, ulen); @@ -2106,15 +5012,27 @@ static int bpf_prog_get_info_by_fd(struct bpf_prog *prog, for (i = 0; i < ulen; i++) if (put_user(prog->aux->used_maps[i]->id, - &user_map_ids[i])) + &user_map_ids[i])) { + mutex_unlock(&prog->aux->used_maps_mutex); return -EFAULT; + } } + mutex_unlock(&prog->aux->used_maps_mutex); err = set_info_rec_size(&info); if (err) return err; - if (!capable(CAP_SYS_ADMIN)) { + bpf_prog_get_stats(prog, &stats); + info.run_time_ns = stats.nsecs; + info.run_cnt = stats.cnt; + info.recursion_misses = stats.misses; + + info.verified_insns = prog->aux->verified_insns; + if (prog->aux->btf) + info.btf_id = btf_obj_id(prog->aux->btf); + + if (!bpf_capable()) { info.jited_prog_len = 0; info.xlated_prog_len = 0; info.nr_jited_ksyms = 0; @@ -2131,22 +5049,22 @@ static int bpf_prog_get_info_by_fd(struct bpf_prog *prog, struct bpf_insn *insns_sanitized; bool fault; - if (prog->blinded && !bpf_dump_raw_ok()) { + if (!prog->blinded || bpf_dump_raw_ok(file->f_cred)) { + insns_sanitized = bpf_insn_prepare_dump(prog, file->f_cred); + if (!insns_sanitized) + return -ENOMEM; + uinsns = u64_to_user_ptr(info.xlated_prog_insns); + ulen = min_t(u32, info.xlated_prog_len, ulen); + fault = copy_to_user(uinsns, insns_sanitized, ulen); + kfree(insns_sanitized); + if (fault) + return -EFAULT; + } else { info.xlated_prog_insns = 0; - goto done; - } - insns_sanitized = bpf_insn_prepare_dump(prog); - if (!insns_sanitized) - return -ENOMEM; - uinsns = u64_to_user_ptr(info.xlated_prog_insns); - ulen = min_t(u32, info.xlated_prog_len, ulen); - fault = copy_to_user(uinsns, insns_sanitized, ulen); - kfree(insns_sanitized); - if (fault) - return -EFAULT; + } } - if (bpf_prog_is_dev_bound(prog->aux)) { + if (bpf_prog_is_offloaded(prog->aux)) { err = bpf_prog_offload_info_fill(&info, prog); if (err) return err; @@ -2169,7 +5087,7 @@ static int bpf_prog_get_info_by_fd(struct bpf_prog *prog, } if (info.jited_prog_len && ulen) { - if (bpf_dump_raw_ok()) { + if (bpf_dump_raw_ok(file->f_cred)) { uinsns = u64_to_user_ptr(info.jited_prog_insns); ulen = min_t(u32, info.jited_prog_len, ulen); @@ -2204,7 +5122,7 @@ static int bpf_prog_get_info_by_fd(struct bpf_prog *prog, ulen = info.nr_jited_ksyms; info.nr_jited_ksyms = prog->aux->func_cnt ? : 1; if (ulen) { - if (bpf_dump_raw_ok()) { + if (bpf_dump_raw_ok(file->f_cred)) { unsigned long ksym_addr; u64 __user *user_ksyms; u32 i; @@ -2235,7 +5153,7 @@ static int bpf_prog_get_info_by_fd(struct bpf_prog *prog, ulen = info.nr_jited_func_lens; info.nr_jited_func_lens = prog->aux->func_cnt ? : 1; if (ulen) { - if (bpf_dump_raw_ok()) { + if (bpf_dump_raw_ok(file->f_cred)) { u32 __user *user_lens; u32 func_len, i; @@ -2259,8 +5177,9 @@ static int bpf_prog_get_info_by_fd(struct bpf_prog *prog, } } - if (prog->aux->btf) - info.btf_id = btf_id(prog->aux->btf); + info.attach_btf_id = prog->aux->attach_btf_id; + if (attach_btf) + info.attach_btf_obj_id = btf_obj_id(attach_btf); ulen = info.nr_func_info; info.nr_func_info = prog->aux->func_info_cnt; @@ -2292,15 +5211,16 @@ static int bpf_prog_get_info_by_fd(struct bpf_prog *prog, else info.nr_jited_line_info = 0; if (info.nr_jited_line_info && ulen) { - if (bpf_dump_raw_ok()) { + if (bpf_dump_raw_ok(file->f_cred)) { + unsigned long line_addr; __u64 __user *user_linfo; u32 i; user_linfo = u64_to_user_ptr(info.jited_line_info); ulen = min_t(u32, info.nr_jited_line_info, ulen); for (i = 0; i < ulen; i++) { - if (put_user((__u64)(long)prog->aux->jited_linfo[i], - &user_linfo[i])) + line_addr = (unsigned long)prog->aux->jited_linfo[i]; + if (put_user((__u64)line_addr, &user_linfo[i])) return -EFAULT; } } else { @@ -2338,40 +5258,68 @@ done: return 0; } -static int bpf_map_get_info_by_fd(struct bpf_map *map, +static int bpf_map_get_info_by_fd(struct file *file, + struct bpf_map *map, const union bpf_attr *attr, union bpf_attr __user *uattr) { struct bpf_map_info __user *uinfo = u64_to_user_ptr(attr->info.info); - struct bpf_map_info info = {}; + struct bpf_map_info info; u32 info_len = attr->info.info_len; int err; - err = bpf_check_uarg_tail_zero(uinfo, sizeof(info), info_len); + err = bpf_check_uarg_tail_zero(USER_BPFPTR(uinfo), sizeof(info), info_len); if (err) return err; info_len = min_t(u32, sizeof(info), info_len); + memset(&info, 0, sizeof(info)); + if (copy_from_user(&info, uinfo, info_len)) + return -EFAULT; + info.type = map->map_type; info.id = map->id; info.key_size = map->key_size; info.value_size = map->value_size; info.max_entries = map->max_entries; info.map_flags = map->map_flags; + info.map_extra = map->map_extra; memcpy(info.name, map->name, sizeof(map->name)); if (map->btf) { - info.btf_id = btf_id(map->btf); + info.btf_id = btf_obj_id(map->btf); info.btf_key_type_id = map->btf_key_type_id; info.btf_value_type_id = map->btf_value_type_id; } + info.btf_vmlinux_value_type_id = map->btf_vmlinux_value_type_id; + if (map->map_type == BPF_MAP_TYPE_STRUCT_OPS) + bpf_map_struct_ops_info_fill(&info, map); - if (bpf_map_is_dev_bound(map)) { + if (bpf_map_is_offloaded(map)) { err = bpf_map_offload_info_fill(&info, map); if (err) return err; } + if (info.hash) { + char __user *uhash = u64_to_user_ptr(info.hash); + + if (!map->ops->map_get_hash) + return -EINVAL; + + if (info.hash_size != SHA256_DIGEST_SIZE) + return -EINVAL; + + err = map->ops->map_get_hash(map, SHA256_DIGEST_SIZE, map->sha); + if (err != 0) + return err; + + if (copy_to_user(uhash, map->sha, SHA256_DIGEST_SIZE) != 0) + return -EFAULT; + } else if (info.hash_size) { + return -EINVAL; + } + if (copy_to_user(uinfo, &info, info_len) || put_user(info_len, &uattr->info.info_len)) return -EFAULT; @@ -2379,7 +5327,8 @@ static int bpf_map_get_info_by_fd(struct bpf_map *map, return 0; } -static int bpf_btf_get_info_by_fd(struct btf *btf, +static int bpf_btf_get_info_by_fd(struct file *file, + struct btf *btf, const union bpf_attr *attr, union bpf_attr __user *uattr) { @@ -2387,66 +5336,155 @@ static int bpf_btf_get_info_by_fd(struct btf *btf, u32 info_len = attr->info.info_len; int err; - err = bpf_check_uarg_tail_zero(uinfo, sizeof(*uinfo), info_len); + err = bpf_check_uarg_tail_zero(USER_BPFPTR(uinfo), sizeof(*uinfo), info_len); if (err) return err; return btf_get_info_by_fd(btf, attr, uattr); } +static int bpf_link_get_info_by_fd(struct file *file, + struct bpf_link *link, + const union bpf_attr *attr, + union bpf_attr __user *uattr) +{ + struct bpf_link_info __user *uinfo = u64_to_user_ptr(attr->info.info); + struct bpf_link_info info; + u32 info_len = attr->info.info_len; + int err; + + err = bpf_check_uarg_tail_zero(USER_BPFPTR(uinfo), sizeof(info), info_len); + if (err) + return err; + info_len = min_t(u32, sizeof(info), info_len); + + memset(&info, 0, sizeof(info)); + if (copy_from_user(&info, uinfo, info_len)) + return -EFAULT; + + info.type = link->type; + info.id = link->id; + if (link->prog) + info.prog_id = link->prog->aux->id; + + if (link->ops->fill_link_info) { + err = link->ops->fill_link_info(link, &info); + if (err) + return err; + } + + if (copy_to_user(uinfo, &info, info_len) || + put_user(info_len, &uattr->info.info_len)) + return -EFAULT; + + return 0; +} + + +static int token_get_info_by_fd(struct file *file, + struct bpf_token *token, + const union bpf_attr *attr, + union bpf_attr __user *uattr) +{ + struct bpf_token_info __user *uinfo = u64_to_user_ptr(attr->info.info); + u32 info_len = attr->info.info_len; + int err; + + err = bpf_check_uarg_tail_zero(USER_BPFPTR(uinfo), sizeof(*uinfo), info_len); + if (err) + return err; + return bpf_token_get_info_by_fd(token, attr, uattr); +} + #define BPF_OBJ_GET_INFO_BY_FD_LAST_FIELD info.info static int bpf_obj_get_info_by_fd(const union bpf_attr *attr, union bpf_attr __user *uattr) { - int ufd = attr->info.bpf_fd; - struct fd f; - int err; - if (CHECK_ATTR(BPF_OBJ_GET_INFO_BY_FD)) return -EINVAL; - f = fdget(ufd); - if (!f.file) + CLASS(fd, f)(attr->info.bpf_fd); + if (fd_empty(f)) return -EBADFD; - if (f.file->f_op == &bpf_prog_fops) - err = bpf_prog_get_info_by_fd(f.file->private_data, attr, + if (fd_file(f)->f_op == &bpf_prog_fops) + return bpf_prog_get_info_by_fd(fd_file(f), fd_file(f)->private_data, attr, uattr); - else if (f.file->f_op == &bpf_map_fops) - err = bpf_map_get_info_by_fd(f.file->private_data, attr, + else if (fd_file(f)->f_op == &bpf_map_fops) + return bpf_map_get_info_by_fd(fd_file(f), fd_file(f)->private_data, attr, uattr); - else if (f.file->f_op == &btf_fops) - err = bpf_btf_get_info_by_fd(f.file->private_data, attr, uattr); - else - err = -EINVAL; - - fdput(f); - return err; + else if (fd_file(f)->f_op == &btf_fops) + return bpf_btf_get_info_by_fd(fd_file(f), fd_file(f)->private_data, attr, uattr); + else if (fd_file(f)->f_op == &bpf_link_fops || fd_file(f)->f_op == &bpf_link_fops_poll) + return bpf_link_get_info_by_fd(fd_file(f), fd_file(f)->private_data, + attr, uattr); + else if (fd_file(f)->f_op == &bpf_token_fops) + return token_get_info_by_fd(fd_file(f), fd_file(f)->private_data, + attr, uattr); + return -EINVAL; } -#define BPF_BTF_LOAD_LAST_FIELD btf_log_level +#define BPF_BTF_LOAD_LAST_FIELD btf_token_fd -static int bpf_btf_load(const union bpf_attr *attr) +static int bpf_btf_load(const union bpf_attr *attr, bpfptr_t uattr, __u32 uattr_size) { + struct bpf_token *token = NULL; + if (CHECK_ATTR(BPF_BTF_LOAD)) return -EINVAL; - if (!capable(CAP_SYS_ADMIN)) + if (attr->btf_flags & ~BPF_F_TOKEN_FD) + return -EINVAL; + + if (attr->btf_flags & BPF_F_TOKEN_FD) { + token = bpf_token_get_from_fd(attr->btf_token_fd); + if (IS_ERR(token)) + return PTR_ERR(token); + if (!bpf_token_allow_cmd(token, BPF_BTF_LOAD)) { + bpf_token_put(token); + token = NULL; + } + } + + if (!bpf_token_capable(token, CAP_BPF)) { + bpf_token_put(token); return -EPERM; + } - return btf_new_fd(attr); + bpf_token_put(token); + + return btf_new_fd(attr, uattr, uattr_size); } -#define BPF_BTF_GET_FD_BY_ID_LAST_FIELD btf_id +#define BPF_BTF_GET_FD_BY_ID_LAST_FIELD fd_by_id_token_fd static int bpf_btf_get_fd_by_id(const union bpf_attr *attr) { + struct bpf_token *token = NULL; + if (CHECK_ATTR(BPF_BTF_GET_FD_BY_ID)) return -EINVAL; - if (!capable(CAP_SYS_ADMIN)) + if (attr->open_flags & ~BPF_F_TOKEN_FD) + return -EINVAL; + + if (attr->open_flags & BPF_F_TOKEN_FD) { + token = bpf_token_get_from_fd(attr->fd_by_id_token_fd); + if (IS_ERR(token)) + return PTR_ERR(token); + if (!bpf_token_allow_cmd(token, BPF_BTF_GET_FD_BY_ID)) { + bpf_token_put(token); + token = NULL; + } + } + + if (!bpf_token_capable(token, CAP_SYS_ADMIN)) { + bpf_token_put(token); return -EPERM; + } + + bpf_token_put(token); return btf_get_fd_by_id(attr->btf_id); } @@ -2471,21 +5509,10 @@ static int bpf_task_fd_query_copy(const union bpf_attr *attr, if (put_user(zero, ubuf)) return -EFAULT; - } else if (input_len >= len + 1) { - /* ubuf can hold the string with NULL terminator */ - if (copy_to_user(ubuf, buf, len + 1)) - return -EFAULT; } else { - /* ubuf cannot hold the string with NULL terminator, - * do a partial copy with NULL terminator. - */ - char zero = '\0'; - - err = -ENOSPC; - if (copy_to_user(ubuf, buf, input_len - 1)) - return -EFAULT; - if (put_user(zero, ubuf + input_len - 1)) - return -EFAULT; + err = bpf_copy_to_user(ubuf, buf, input_len, len); + if (err == -EFAULT) + return err; } } @@ -2506,7 +5533,6 @@ static int bpf_task_fd_query(const union bpf_attr *attr, pid_t pid = attr->task_fd_query.pid; u32 fd = attr->task_fd_query.fd; const struct perf_event *event; - struct files_struct *files; struct task_struct *task; struct file *file; int err; @@ -2520,37 +5546,33 @@ static int bpf_task_fd_query(const union bpf_attr *attr, if (attr->task_fd_query.flags != 0) return -EINVAL; + rcu_read_lock(); task = get_pid_task(find_vpid(pid), PIDTYPE_PID); + rcu_read_unlock(); if (!task) return -ENOENT; - files = get_files_struct(task); - put_task_struct(task); - if (!files) - return -ENOENT; - err = 0; - spin_lock(&files->file_lock); - file = fcheck_files(files, fd); + file = fget_task(task, fd); + put_task_struct(task); if (!file) - err = -EBADF; - else - get_file(file); - spin_unlock(&files->file_lock); - put_files_struct(files); + return -EBADF; - if (err) - goto out; + if (file->f_op == &bpf_link_fops || file->f_op == &bpf_link_fops_poll) { + struct bpf_link *link = file->private_data; - if (file->f_op == &bpf_raw_tp_fops) { - struct bpf_raw_tracepoint *raw_tp = file->private_data; - struct bpf_raw_event_map *btp = raw_tp->btp; + if (link->ops == &bpf_raw_tp_link_lops) { + struct bpf_raw_tp_link *raw_tp = + container_of(link, struct bpf_raw_tp_link, link); + struct bpf_raw_event_map *btp = raw_tp->btp; - err = bpf_task_fd_query_copy(attr, uattr, - raw_tp->prog->aux->id, - BPF_FD_TYPE_RAW_TRACEPOINT, - btp->tp->name, 0, 0); - goto put_file; + err = bpf_task_fd_query_copy(attr, uattr, + raw_tp->link.prog->aux->id, + BPF_FD_TYPE_RAW_TRACEPOINT, + btp->tp->name, 0, 0); + goto put_file; + } + goto out_not_supp; } event = perf_get_event(file); @@ -2561,7 +5583,7 @@ static int bpf_task_fd_query(const union bpf_attr *attr, err = bpf_get_perf_event_info(event, &prog_id, &fd_type, &buf, &probe_offset, - &probe_addr); + &probe_addr, NULL); if (!err) err = bpf_task_fd_query_copy(attr, uattr, prog_id, fd_type, buf, @@ -2570,52 +5592,576 @@ static int bpf_task_fd_query(const union bpf_attr *attr, goto put_file; } +out_not_supp: err = -ENOTSUPP; put_file: fput(file); -out: return err; } -SYSCALL_DEFINE3(bpf, int, cmd, union bpf_attr __user *, uattr, unsigned int, size) +#define BPF_MAP_BATCH_LAST_FIELD batch.flags + +#define BPF_DO_BATCH(fn, ...) \ + do { \ + if (!fn) { \ + err = -ENOTSUPP; \ + goto err_put; \ + } \ + err = fn(__VA_ARGS__); \ + } while (0) + +static int bpf_map_do_batch(const union bpf_attr *attr, + union bpf_attr __user *uattr, + int cmd) { - union bpf_attr attr = {}; + bool has_read = cmd == BPF_MAP_LOOKUP_BATCH || + cmd == BPF_MAP_LOOKUP_AND_DELETE_BATCH; + bool has_write = cmd != BPF_MAP_LOOKUP_BATCH; + struct bpf_map *map; int err; - if (sysctl_unprivileged_bpf_disabled && !capable(CAP_SYS_ADMIN)) + if (CHECK_ATTR(BPF_MAP_BATCH)) + return -EINVAL; + + CLASS(fd, f)(attr->batch.map_fd); + + map = __bpf_map_get(f); + if (IS_ERR(map)) + return PTR_ERR(map); + if (has_write) + bpf_map_write_active_inc(map); + if (has_read && !(map_get_sys_perms(map, f) & FMODE_CAN_READ)) { + err = -EPERM; + goto err_put; + } + if (has_write && !(map_get_sys_perms(map, f) & FMODE_CAN_WRITE)) { + err = -EPERM; + goto err_put; + } + + if (cmd == BPF_MAP_LOOKUP_BATCH) + BPF_DO_BATCH(map->ops->map_lookup_batch, map, attr, uattr); + else if (cmd == BPF_MAP_LOOKUP_AND_DELETE_BATCH) + BPF_DO_BATCH(map->ops->map_lookup_and_delete_batch, map, attr, uattr); + else if (cmd == BPF_MAP_UPDATE_BATCH) + BPF_DO_BATCH(map->ops->map_update_batch, map, fd_file(f), attr, uattr); + else + BPF_DO_BATCH(map->ops->map_delete_batch, map, attr, uattr); +err_put: + if (has_write) { + maybe_wait_bpf_programs(map); + bpf_map_write_active_dec(map); + } + return err; +} + +#define BPF_LINK_CREATE_LAST_FIELD link_create.uprobe_multi.pid +static int link_create(union bpf_attr *attr, bpfptr_t uattr) +{ + struct bpf_prog *prog; + int ret; + + if (CHECK_ATTR(BPF_LINK_CREATE)) + return -EINVAL; + + if (attr->link_create.attach_type == BPF_STRUCT_OPS) + return bpf_struct_ops_link_create(attr); + + prog = bpf_prog_get(attr->link_create.prog_fd); + if (IS_ERR(prog)) + return PTR_ERR(prog); + + ret = bpf_prog_attach_check_attach_type(prog, + attr->link_create.attach_type); + if (ret) + goto out; + + switch (prog->type) { + case BPF_PROG_TYPE_CGROUP_SKB: + case BPF_PROG_TYPE_CGROUP_SOCK: + case BPF_PROG_TYPE_CGROUP_SOCK_ADDR: + case BPF_PROG_TYPE_SOCK_OPS: + case BPF_PROG_TYPE_CGROUP_DEVICE: + case BPF_PROG_TYPE_CGROUP_SYSCTL: + case BPF_PROG_TYPE_CGROUP_SOCKOPT: + ret = cgroup_bpf_link_attach(attr, prog); + break; + case BPF_PROG_TYPE_EXT: + ret = bpf_tracing_prog_attach(prog, + attr->link_create.target_fd, + attr->link_create.target_btf_id, + attr->link_create.tracing.cookie, + attr->link_create.attach_type); + break; + case BPF_PROG_TYPE_LSM: + case BPF_PROG_TYPE_TRACING: + if (attr->link_create.attach_type != prog->expected_attach_type) { + ret = -EINVAL; + goto out; + } + if (prog->expected_attach_type == BPF_TRACE_RAW_TP) + ret = bpf_raw_tp_link_attach(prog, NULL, attr->link_create.tracing.cookie, + attr->link_create.attach_type); + else if (prog->expected_attach_type == BPF_TRACE_ITER) + ret = bpf_iter_link_attach(attr, uattr, prog); + else if (prog->expected_attach_type == BPF_LSM_CGROUP) + ret = cgroup_bpf_link_attach(attr, prog); + else + ret = bpf_tracing_prog_attach(prog, + attr->link_create.target_fd, + attr->link_create.target_btf_id, + attr->link_create.tracing.cookie, + attr->link_create.attach_type); + break; + case BPF_PROG_TYPE_FLOW_DISSECTOR: + case BPF_PROG_TYPE_SK_LOOKUP: + ret = netns_bpf_link_create(attr, prog); + break; + case BPF_PROG_TYPE_SK_MSG: + case BPF_PROG_TYPE_SK_SKB: + ret = sock_map_link_create(attr, prog); + break; +#ifdef CONFIG_NET + case BPF_PROG_TYPE_XDP: + ret = bpf_xdp_link_attach(attr, prog); + break; + case BPF_PROG_TYPE_SCHED_CLS: + if (attr->link_create.attach_type == BPF_TCX_INGRESS || + attr->link_create.attach_type == BPF_TCX_EGRESS) + ret = tcx_link_attach(attr, prog); + else + ret = netkit_link_attach(attr, prog); + break; + case BPF_PROG_TYPE_NETFILTER: + ret = bpf_nf_link_attach(attr, prog); + break; +#endif + case BPF_PROG_TYPE_PERF_EVENT: + case BPF_PROG_TYPE_TRACEPOINT: + ret = bpf_perf_link_attach(attr, prog); + break; + case BPF_PROG_TYPE_KPROBE: + if (attr->link_create.attach_type == BPF_PERF_EVENT) + ret = bpf_perf_link_attach(attr, prog); + else if (attr->link_create.attach_type == BPF_TRACE_KPROBE_MULTI || + attr->link_create.attach_type == BPF_TRACE_KPROBE_SESSION) + ret = bpf_kprobe_multi_link_attach(attr, prog); + else if (attr->link_create.attach_type == BPF_TRACE_UPROBE_MULTI || + attr->link_create.attach_type == BPF_TRACE_UPROBE_SESSION) + ret = bpf_uprobe_multi_link_attach(attr, prog); + break; + default: + ret = -EINVAL; + } + +out: + if (ret < 0) + bpf_prog_put(prog); + return ret; +} + +static int link_update_map(struct bpf_link *link, union bpf_attr *attr) +{ + struct bpf_map *new_map, *old_map = NULL; + int ret; + + new_map = bpf_map_get(attr->link_update.new_map_fd); + if (IS_ERR(new_map)) + return PTR_ERR(new_map); + + if (attr->link_update.flags & BPF_F_REPLACE) { + old_map = bpf_map_get(attr->link_update.old_map_fd); + if (IS_ERR(old_map)) { + ret = PTR_ERR(old_map); + goto out_put; + } + } else if (attr->link_update.old_map_fd) { + ret = -EINVAL; + goto out_put; + } + + ret = link->ops->update_map(link, new_map, old_map); + + if (old_map) + bpf_map_put(old_map); +out_put: + bpf_map_put(new_map); + return ret; +} + +#define BPF_LINK_UPDATE_LAST_FIELD link_update.old_prog_fd + +static int link_update(union bpf_attr *attr) +{ + struct bpf_prog *old_prog = NULL, *new_prog; + struct bpf_link *link; + u32 flags; + int ret; + + if (CHECK_ATTR(BPF_LINK_UPDATE)) + return -EINVAL; + + flags = attr->link_update.flags; + if (flags & ~BPF_F_REPLACE) + return -EINVAL; + + link = bpf_link_get_from_fd(attr->link_update.link_fd); + if (IS_ERR(link)) + return PTR_ERR(link); + + if (link->ops->update_map) { + ret = link_update_map(link, attr); + goto out_put_link; + } + + new_prog = bpf_prog_get(attr->link_update.new_prog_fd); + if (IS_ERR(new_prog)) { + ret = PTR_ERR(new_prog); + goto out_put_link; + } + + if (flags & BPF_F_REPLACE) { + old_prog = bpf_prog_get(attr->link_update.old_prog_fd); + if (IS_ERR(old_prog)) { + ret = PTR_ERR(old_prog); + old_prog = NULL; + goto out_put_progs; + } + } else if (attr->link_update.old_prog_fd) { + ret = -EINVAL; + goto out_put_progs; + } + + if (link->ops->update_prog) + ret = link->ops->update_prog(link, new_prog, old_prog); + else + ret = -EINVAL; + +out_put_progs: + if (old_prog) + bpf_prog_put(old_prog); + if (ret) + bpf_prog_put(new_prog); +out_put_link: + bpf_link_put_direct(link); + return ret; +} + +#define BPF_LINK_DETACH_LAST_FIELD link_detach.link_fd + +static int link_detach(union bpf_attr *attr) +{ + struct bpf_link *link; + int ret; + + if (CHECK_ATTR(BPF_LINK_DETACH)) + return -EINVAL; + + link = bpf_link_get_from_fd(attr->link_detach.link_fd); + if (IS_ERR(link)) + return PTR_ERR(link); + + if (link->ops->detach) + ret = link->ops->detach(link); + else + ret = -EOPNOTSUPP; + + bpf_link_put_direct(link); + return ret; +} + +struct bpf_link *bpf_link_inc_not_zero(struct bpf_link *link) +{ + return atomic64_fetch_add_unless(&link->refcnt, 1, 0) ? link : ERR_PTR(-ENOENT); +} +EXPORT_SYMBOL(bpf_link_inc_not_zero); + +struct bpf_link *bpf_link_by_id(u32 id) +{ + struct bpf_link *link; + + if (!id) + return ERR_PTR(-ENOENT); + + spin_lock_bh(&link_idr_lock); + /* before link is "settled", ID is 0, pretend it doesn't exist yet */ + link = idr_find(&link_idr, id); + if (link) { + if (link->id) + link = bpf_link_inc_not_zero(link); + else + link = ERR_PTR(-EAGAIN); + } else { + link = ERR_PTR(-ENOENT); + } + spin_unlock_bh(&link_idr_lock); + return link; +} + +struct bpf_link *bpf_link_get_curr_or_next(u32 *id) +{ + struct bpf_link *link; + + spin_lock_bh(&link_idr_lock); +again: + link = idr_get_next(&link_idr, id); + if (link) { + link = bpf_link_inc_not_zero(link); + if (IS_ERR(link)) { + (*id)++; + goto again; + } + } + spin_unlock_bh(&link_idr_lock); + + return link; +} + +#define BPF_LINK_GET_FD_BY_ID_LAST_FIELD link_id + +static int bpf_link_get_fd_by_id(const union bpf_attr *attr) +{ + struct bpf_link *link; + u32 id = attr->link_id; + int fd; + + if (CHECK_ATTR(BPF_LINK_GET_FD_BY_ID)) + return -EINVAL; + + if (!capable(CAP_SYS_ADMIN)) return -EPERM; + link = bpf_link_by_id(id); + if (IS_ERR(link)) + return PTR_ERR(link); + + fd = bpf_link_new_fd(link); + if (fd < 0) + bpf_link_put_direct(link); + + return fd; +} + +DEFINE_MUTEX(bpf_stats_enabled_mutex); + +static int bpf_stats_release(struct inode *inode, struct file *file) +{ + mutex_lock(&bpf_stats_enabled_mutex); + static_key_slow_dec(&bpf_stats_enabled_key.key); + mutex_unlock(&bpf_stats_enabled_mutex); + return 0; +} + +static const struct file_operations bpf_stats_fops = { + .release = bpf_stats_release, +}; + +static int bpf_enable_runtime_stats(void) +{ + int fd; + + mutex_lock(&bpf_stats_enabled_mutex); + + /* Set a very high limit to avoid overflow */ + if (static_key_count(&bpf_stats_enabled_key.key) > INT_MAX / 2) { + mutex_unlock(&bpf_stats_enabled_mutex); + return -EBUSY; + } + + fd = anon_inode_getfd("bpf-stats", &bpf_stats_fops, NULL, O_CLOEXEC); + if (fd >= 0) + static_key_slow_inc(&bpf_stats_enabled_key.key); + + mutex_unlock(&bpf_stats_enabled_mutex); + return fd; +} + +#define BPF_ENABLE_STATS_LAST_FIELD enable_stats.type + +static int bpf_enable_stats(union bpf_attr *attr) +{ + + if (CHECK_ATTR(BPF_ENABLE_STATS)) + return -EINVAL; + + if (!capable(CAP_SYS_ADMIN)) + return -EPERM; + + switch (attr->enable_stats.type) { + case BPF_STATS_RUN_TIME: + return bpf_enable_runtime_stats(); + default: + break; + } + return -EINVAL; +} + +#define BPF_ITER_CREATE_LAST_FIELD iter_create.flags + +static int bpf_iter_create(union bpf_attr *attr) +{ + struct bpf_link *link; + int err; + + if (CHECK_ATTR(BPF_ITER_CREATE)) + return -EINVAL; + + if (attr->iter_create.flags) + return -EINVAL; + + link = bpf_link_get_from_fd(attr->iter_create.link_fd); + if (IS_ERR(link)) + return PTR_ERR(link); + + err = bpf_iter_new_fd(link); + bpf_link_put_direct(link); + + return err; +} + +#define BPF_PROG_BIND_MAP_LAST_FIELD prog_bind_map.flags + +static int bpf_prog_bind_map(union bpf_attr *attr) +{ + struct bpf_prog *prog; + struct bpf_map *map; + struct bpf_map **used_maps_old, **used_maps_new; + int i, ret = 0; + + if (CHECK_ATTR(BPF_PROG_BIND_MAP)) + return -EINVAL; + + if (attr->prog_bind_map.flags) + return -EINVAL; + + prog = bpf_prog_get(attr->prog_bind_map.prog_fd); + if (IS_ERR(prog)) + return PTR_ERR(prog); + + map = bpf_map_get(attr->prog_bind_map.map_fd); + if (IS_ERR(map)) { + ret = PTR_ERR(map); + goto out_prog_put; + } + + mutex_lock(&prog->aux->used_maps_mutex); + + used_maps_old = prog->aux->used_maps; + + for (i = 0; i < prog->aux->used_map_cnt; i++) + if (used_maps_old[i] == map) { + bpf_map_put(map); + goto out_unlock; + } + + used_maps_new = kmalloc_array(prog->aux->used_map_cnt + 1, + sizeof(used_maps_new[0]), + GFP_KERNEL); + if (!used_maps_new) { + ret = -ENOMEM; + goto out_unlock; + } + + /* The bpf program will not access the bpf map, but for the sake of + * simplicity, increase sleepable_refcnt for sleepable program as well. + */ + if (prog->sleepable) + atomic64_inc(&map->sleepable_refcnt); + memcpy(used_maps_new, used_maps_old, + sizeof(used_maps_old[0]) * prog->aux->used_map_cnt); + used_maps_new[prog->aux->used_map_cnt] = map; + + prog->aux->used_map_cnt++; + prog->aux->used_maps = used_maps_new; + + kfree(used_maps_old); + +out_unlock: + mutex_unlock(&prog->aux->used_maps_mutex); + + if (ret) + bpf_map_put(map); +out_prog_put: + bpf_prog_put(prog); + return ret; +} + +#define BPF_TOKEN_CREATE_LAST_FIELD token_create.bpffs_fd + +static int token_create(union bpf_attr *attr) +{ + if (CHECK_ATTR(BPF_TOKEN_CREATE)) + return -EINVAL; + + /* no flags are supported yet */ + if (attr->token_create.flags) + return -EINVAL; + + return bpf_token_create(attr); +} + +#define BPF_PROG_STREAM_READ_BY_FD_LAST_FIELD prog_stream_read.prog_fd + +static int prog_stream_read(union bpf_attr *attr) +{ + char __user *buf = u64_to_user_ptr(attr->prog_stream_read.stream_buf); + u32 len = attr->prog_stream_read.stream_buf_len; + struct bpf_prog *prog; + int ret; + + if (CHECK_ATTR(BPF_PROG_STREAM_READ_BY_FD)) + return -EINVAL; + + prog = bpf_prog_get(attr->prog_stream_read.prog_fd); + if (IS_ERR(prog)) + return PTR_ERR(prog); + + ret = bpf_prog_stream_read(prog, attr->prog_stream_read.stream_id, buf, len); + bpf_prog_put(prog); + + return ret; +} + +static int __sys_bpf(enum bpf_cmd cmd, bpfptr_t uattr, unsigned int size) +{ + union bpf_attr attr; + int err; + err = bpf_check_uarg_tail_zero(uattr, sizeof(attr), size); if (err) return err; size = min_t(u32, size, sizeof(attr)); /* copy attributes from user space, may be less than sizeof(bpf_attr) */ - if (copy_from_user(&attr, uattr, size) != 0) + memset(&attr, 0, sizeof(attr)); + if (copy_from_bpfptr(&attr, uattr, size) != 0) return -EFAULT; - err = security_bpf(cmd, &attr, size); + err = security_bpf(cmd, &attr, size, uattr.is_kernel); if (err < 0) return err; switch (cmd) { case BPF_MAP_CREATE: - err = map_create(&attr); + err = map_create(&attr, uattr); break; case BPF_MAP_LOOKUP_ELEM: err = map_lookup_elem(&attr); break; case BPF_MAP_UPDATE_ELEM: - err = map_update_elem(&attr); + err = map_update_elem(&attr, uattr); break; case BPF_MAP_DELETE_ELEM: - err = map_delete_elem(&attr); + err = map_delete_elem(&attr, uattr); break; case BPF_MAP_GET_NEXT_KEY: err = map_get_next_key(&attr); break; + case BPF_MAP_FREEZE: + err = map_freeze(&attr); + break; case BPF_PROG_LOAD: - err = bpf_prog_load(&attr, uattr); + err = bpf_prog_load(&attr, uattr, size); break; case BPF_OBJ_PIN: err = bpf_obj_pin(&attr); @@ -2630,19 +6176,23 @@ SYSCALL_DEFINE3(bpf, int, cmd, union bpf_attr __user *, uattr, unsigned int, siz err = bpf_prog_detach(&attr); break; case BPF_PROG_QUERY: - err = bpf_prog_query(&attr, uattr); + err = bpf_prog_query(&attr, uattr.user); break; case BPF_PROG_TEST_RUN: - err = bpf_prog_test_run(&attr, uattr); + err = bpf_prog_test_run(&attr, uattr.user); break; case BPF_PROG_GET_NEXT_ID: - err = bpf_obj_get_next_id(&attr, uattr, + err = bpf_obj_get_next_id(&attr, uattr.user, &prog_idr, &prog_idr_lock); break; case BPF_MAP_GET_NEXT_ID: - err = bpf_obj_get_next_id(&attr, uattr, + err = bpf_obj_get_next_id(&attr, uattr.user, &map_idr, &map_idr_lock); break; + case BPF_BTF_GET_NEXT_ID: + err = bpf_obj_get_next_id(&attr, uattr.user, + &btf_idr, &btf_idr_lock); + break; case BPF_PROG_GET_FD_BY_ID: err = bpf_prog_get_fd_by_id(&attr); break; @@ -2650,23 +6200,67 @@ SYSCALL_DEFINE3(bpf, int, cmd, union bpf_attr __user *, uattr, unsigned int, siz err = bpf_map_get_fd_by_id(&attr); break; case BPF_OBJ_GET_INFO_BY_FD: - err = bpf_obj_get_info_by_fd(&attr, uattr); + err = bpf_obj_get_info_by_fd(&attr, uattr.user); break; case BPF_RAW_TRACEPOINT_OPEN: err = bpf_raw_tracepoint_open(&attr); break; case BPF_BTF_LOAD: - err = bpf_btf_load(&attr); + err = bpf_btf_load(&attr, uattr, size); break; case BPF_BTF_GET_FD_BY_ID: err = bpf_btf_get_fd_by_id(&attr); break; case BPF_TASK_FD_QUERY: - err = bpf_task_fd_query(&attr, uattr); + err = bpf_task_fd_query(&attr, uattr.user); break; case BPF_MAP_LOOKUP_AND_DELETE_ELEM: err = map_lookup_and_delete_elem(&attr); break; + case BPF_MAP_LOOKUP_BATCH: + err = bpf_map_do_batch(&attr, uattr.user, BPF_MAP_LOOKUP_BATCH); + break; + case BPF_MAP_LOOKUP_AND_DELETE_BATCH: + err = bpf_map_do_batch(&attr, uattr.user, + BPF_MAP_LOOKUP_AND_DELETE_BATCH); + break; + case BPF_MAP_UPDATE_BATCH: + err = bpf_map_do_batch(&attr, uattr.user, BPF_MAP_UPDATE_BATCH); + break; + case BPF_MAP_DELETE_BATCH: + err = bpf_map_do_batch(&attr, uattr.user, BPF_MAP_DELETE_BATCH); + break; + case BPF_LINK_CREATE: + err = link_create(&attr, uattr); + break; + case BPF_LINK_UPDATE: + err = link_update(&attr); + break; + case BPF_LINK_GET_FD_BY_ID: + err = bpf_link_get_fd_by_id(&attr); + break; + case BPF_LINK_GET_NEXT_ID: + err = bpf_obj_get_next_id(&attr, uattr.user, + &link_idr, &link_idr_lock); + break; + case BPF_ENABLE_STATS: + err = bpf_enable_stats(&attr); + break; + case BPF_ITER_CREATE: + err = bpf_iter_create(&attr); + break; + case BPF_LINK_DETACH: + err = link_detach(&attr); + break; + case BPF_PROG_BIND_MAP: + err = bpf_prog_bind_map(&attr); + break; + case BPF_TOKEN_CREATE: + err = token_create(&attr); + break; + case BPF_PROG_STREAM_READ_BY_FD: + err = prog_stream_read(&attr); + break; default: err = -EINVAL; break; @@ -2674,3 +6268,261 @@ SYSCALL_DEFINE3(bpf, int, cmd, union bpf_attr __user *, uattr, unsigned int, siz return err; } + +SYSCALL_DEFINE3(bpf, int, cmd, union bpf_attr __user *, uattr, unsigned int, size) +{ + return __sys_bpf(cmd, USER_BPFPTR(uattr), size); +} + +static bool syscall_prog_is_valid_access(int off, int size, + enum bpf_access_type type, + const struct bpf_prog *prog, + struct bpf_insn_access_aux *info) +{ + if (off < 0 || off >= U16_MAX) + return false; + if (off % size != 0) + return false; + return true; +} + +BPF_CALL_3(bpf_sys_bpf, int, cmd, union bpf_attr *, attr, u32, attr_size) +{ + switch (cmd) { + case BPF_MAP_CREATE: + case BPF_MAP_DELETE_ELEM: + case BPF_MAP_UPDATE_ELEM: + case BPF_MAP_FREEZE: + case BPF_MAP_GET_FD_BY_ID: + case BPF_PROG_LOAD: + case BPF_BTF_LOAD: + case BPF_LINK_CREATE: + case BPF_RAW_TRACEPOINT_OPEN: + break; + default: + return -EINVAL; + } + return __sys_bpf(cmd, KERNEL_BPFPTR(attr), attr_size); +} + + +/* To shut up -Wmissing-prototypes. + * This function is used by the kernel light skeleton + * to load bpf programs when modules are loaded or during kernel boot. + * See tools/lib/bpf/skel_internal.h + */ +int kern_sys_bpf(int cmd, union bpf_attr *attr, unsigned int size); + +int kern_sys_bpf(int cmd, union bpf_attr *attr, unsigned int size) +{ + struct bpf_prog * __maybe_unused prog; + struct bpf_tramp_run_ctx __maybe_unused run_ctx; + + switch (cmd) { +#ifdef CONFIG_BPF_JIT /* __bpf_prog_enter_sleepable used by trampoline and JIT */ + case BPF_PROG_TEST_RUN: + if (attr->test.data_in || attr->test.data_out || + attr->test.ctx_out || attr->test.duration || + attr->test.repeat || attr->test.flags) + return -EINVAL; + + prog = bpf_prog_get_type(attr->test.prog_fd, BPF_PROG_TYPE_SYSCALL); + if (IS_ERR(prog)) + return PTR_ERR(prog); + + if (attr->test.ctx_size_in < prog->aux->max_ctx_offset || + attr->test.ctx_size_in > U16_MAX) { + bpf_prog_put(prog); + return -EINVAL; + } + + run_ctx.bpf_cookie = 0; + if (!__bpf_prog_enter_sleepable_recur(prog, &run_ctx)) { + /* recursion detected */ + __bpf_prog_exit_sleepable_recur(prog, 0, &run_ctx); + bpf_prog_put(prog); + return -EBUSY; + } + attr->test.retval = bpf_prog_run(prog, (void *) (long) attr->test.ctx_in); + __bpf_prog_exit_sleepable_recur(prog, 0 /* bpf_prog_run does runtime stats */, + &run_ctx); + bpf_prog_put(prog); + return 0; +#endif + default: + return ____bpf_sys_bpf(cmd, attr, size); + } +} +EXPORT_SYMBOL_NS(kern_sys_bpf, "BPF_INTERNAL"); + +static const struct bpf_func_proto bpf_sys_bpf_proto = { + .func = bpf_sys_bpf, + .gpl_only = false, + .ret_type = RET_INTEGER, + .arg1_type = ARG_ANYTHING, + .arg2_type = ARG_PTR_TO_MEM | MEM_RDONLY, + .arg3_type = ARG_CONST_SIZE, +}; + +const struct bpf_func_proto * __weak +tracing_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) +{ + return bpf_base_func_proto(func_id, prog); +} + +BPF_CALL_1(bpf_sys_close, u32, fd) +{ + /* When bpf program calls this helper there should not be + * an fdget() without matching completed fdput(). + * This helper is allowed in the following callchain only: + * sys_bpf->prog_test_run->bpf_prog->bpf_sys_close + */ + return close_fd(fd); +} + +static const struct bpf_func_proto bpf_sys_close_proto = { + .func = bpf_sys_close, + .gpl_only = false, + .ret_type = RET_INTEGER, + .arg1_type = ARG_ANYTHING, +}; + +BPF_CALL_4(bpf_kallsyms_lookup_name, const char *, name, int, name_sz, int, flags, u64 *, res) +{ + *res = 0; + if (flags) + return -EINVAL; + + if (name_sz <= 1 || name[name_sz - 1]) + return -EINVAL; + + if (!bpf_dump_raw_ok(current_cred())) + return -EPERM; + + *res = kallsyms_lookup_name(name); + return *res ? 0 : -ENOENT; +} + +static const struct bpf_func_proto bpf_kallsyms_lookup_name_proto = { + .func = bpf_kallsyms_lookup_name, + .gpl_only = false, + .ret_type = RET_INTEGER, + .arg1_type = ARG_PTR_TO_MEM, + .arg2_type = ARG_CONST_SIZE_OR_ZERO, + .arg3_type = ARG_ANYTHING, + .arg4_type = ARG_PTR_TO_FIXED_SIZE_MEM | MEM_UNINIT | MEM_WRITE | MEM_ALIGNED, + .arg4_size = sizeof(u64), +}; + +static const struct bpf_func_proto * +syscall_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) +{ + switch (func_id) { + case BPF_FUNC_sys_bpf: + return !bpf_token_capable(prog->aux->token, CAP_PERFMON) + ? NULL : &bpf_sys_bpf_proto; + case BPF_FUNC_btf_find_by_name_kind: + return &bpf_btf_find_by_name_kind_proto; + case BPF_FUNC_sys_close: + return &bpf_sys_close_proto; + case BPF_FUNC_kallsyms_lookup_name: + return &bpf_kallsyms_lookup_name_proto; + default: + return tracing_prog_func_proto(func_id, prog); + } +} + +const struct bpf_verifier_ops bpf_syscall_verifier_ops = { + .get_func_proto = syscall_prog_func_proto, + .is_valid_access = syscall_prog_is_valid_access, +}; + +const struct bpf_prog_ops bpf_syscall_prog_ops = { + .test_run = bpf_prog_test_run_syscall, +}; + +#ifdef CONFIG_SYSCTL +static int bpf_stats_handler(const struct ctl_table *table, int write, + void *buffer, size_t *lenp, loff_t *ppos) +{ + struct static_key *key = (struct static_key *)table->data; + static int saved_val; + int val, ret; + struct ctl_table tmp = { + .data = &val, + .maxlen = sizeof(val), + .mode = table->mode, + .extra1 = SYSCTL_ZERO, + .extra2 = SYSCTL_ONE, + }; + + if (write && !capable(CAP_SYS_ADMIN)) + return -EPERM; + + mutex_lock(&bpf_stats_enabled_mutex); + val = saved_val; + ret = proc_dointvec_minmax(&tmp, write, buffer, lenp, ppos); + if (write && !ret && val != saved_val) { + if (val) + static_key_slow_inc(key); + else + static_key_slow_dec(key); + saved_val = val; + } + mutex_unlock(&bpf_stats_enabled_mutex); + return ret; +} + +void __weak unpriv_ebpf_notify(int new_state) +{ +} + +static int bpf_unpriv_handler(const struct ctl_table *table, int write, + void *buffer, size_t *lenp, loff_t *ppos) +{ + int ret, unpriv_enable = *(int *)table->data; + bool locked_state = unpriv_enable == 1; + struct ctl_table tmp = *table; + + if (write && !capable(CAP_SYS_ADMIN)) + return -EPERM; + + tmp.data = &unpriv_enable; + ret = proc_dointvec_minmax(&tmp, write, buffer, lenp, ppos); + if (write && !ret) { + if (locked_state && unpriv_enable != 1) + return -EPERM; + *(int *)table->data = unpriv_enable; + } + + if (write) + unpriv_ebpf_notify(unpriv_enable); + + return ret; +} + +static const struct ctl_table bpf_syscall_table[] = { + { + .procname = "unprivileged_bpf_disabled", + .data = &sysctl_unprivileged_bpf_disabled, + .maxlen = sizeof(sysctl_unprivileged_bpf_disabled), + .mode = 0644, + .proc_handler = bpf_unpriv_handler, + .extra1 = SYSCTL_ZERO, + .extra2 = SYSCTL_TWO, + }, + { + .procname = "bpf_stats_enabled", + .data = &bpf_stats_enabled_key.key, + .mode = 0644, + .proc_handler = bpf_stats_handler, + }, +}; + +static int __init bpf_syscall_sysctl_init(void) +{ + register_sysctl_init("kernel", bpf_syscall_table); + return 0; +} +late_initcall(bpf_syscall_sysctl_init); +#endif /* CONFIG_SYSCTL */ |