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linux/kernel/bpf/syscall.c
Andrii Nakryiko 1f6cb19be2 bpf: Prevent re-mmap()'ing BPF map as writable for initially r/o mapping 
VM_MAYWRITE flag during initial memory mapping determines if already mmap()'ed
pages can be later remapped as writable ones through mprotect() call. To
prevent user application to rewrite contents of memory-mapped as read-only and
subsequently frozen BPF map, remove VM_MAYWRITE flag completely on initially
read-only mapping.

Alternatively, we could treat any memory-mapping on unfrozen map as writable
and bump writecnt instead. But there is little legitimate reason to map
BPF map as read-only and then re-mmap() it as writable through mprotect(),
instead of just mmap()'ing it as read/write from the very beginning.

Also, at the suggestion of Jann Horn, drop unnecessary refcounting in mmap
operations. We can just rely on VMA holding reference to BPF map's file
properly.

Fixes: fc9702273e ("bpf: Add mmap() support for BPF_MAP_TYPE_ARRAY")
Reported-by: Jann Horn <jannh@google.com>
Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Reviewed-by: Jann Horn <jannh@google.com>
Link: https://lore.kernel.org/bpf/20200410202613.3679837-1-andriin@fb.com
2020-04-14 21:28:57 +02:00

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// SPDX-License-Identifier: GPL-2.0-only
/* Copyright (c) 2011-2014 PLUMgrid, http://plumgrid.com
*/
#include <linux/bpf.h>
#include <linux/bpf_trace.h>
#include <linux/bpf_lirc.h>
#include <linux/btf.h>
#include <linux/syscalls.h>
#include <linux/slab.h>
#include <linux/sched/signal.h>
#include <linux/vmalloc.h>
#include <linux/mmzone.h>
#include <linux/anon_inodes.h>
#include <linux/fdtable.h>
#include <linux/file.h>
#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>
#include <linux/audit.h>
#include <uapi/linux/btf.h>
#include <linux/bpf_lsm.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_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);
static DEFINE_IDR(prog_idr);
static DEFINE_SPINLOCK(prog_idr_lock);
static DEFINE_IDR(map_idr);
static DEFINE_SPINLOCK(map_idr_lock);
int sysctl_unprivileged_bpf_disabled __read_mostly;
static const struct bpf_map_ops * const bpf_map_types[] = {
#define BPF_PROG_TYPE(_id, _name, prog_ctx_type, kern_ctx_type)
#define BPF_MAP_TYPE(_id, _ops) \
[_id] = &_ops,
#include <linux/bpf_types.h>
#undef BPF_PROG_TYPE
#undef BPF_MAP_TYPE
};
/*
* If we're handed a bigger struct than we know of, ensure all the unknown bits
* are 0 - i.e. new user-space does not rely on any kernel feature extensions
* we don't know about yet.
*
* There is a ToCToU between this function call and the following
* 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,
size_t expected_size,
size_t actual_size)
{
unsigned char __user *addr;
unsigned char __user *end;
unsigned char val;
int err;
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;
}
const struct bpf_map_ops bpf_map_offload_ops = {
.map_alloc = bpf_map_offload_map_alloc,
.map_free = bpf_map_offload_map_free,
.map_check_btf = map_check_no_btf,
};
static struct bpf_map *find_and_alloc_map(union bpf_attr *attr)
{
const struct bpf_map_ops *ops;
u32 type = attr->map_type;
struct bpf_map *map;
int err;
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);
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;
}
static u32 bpf_map_value_size(struct bpf_map *map)
{
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;
}
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();
}
static int bpf_map_update_value(struct bpf_map *map, struct fd f, void *key,
void *value, __u64 flags)
{
int err;
/* Need to create a kthread, thus must support schedule */
if (bpf_map_is_dev_bound(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_SOCKHASH ||
map->map_type == BPF_MAP_TYPE_SOCKMAP ||
map->map_type == BPF_MAP_TYPE_STRUCT_OPS) {
return map->ops->map_update_elem(map, key, value, flags);
} else if (IS_FD_PROG_ARRAY(map)) {
return bpf_fd_array_map_update_elem(map, f.file, key, value,
flags);
}
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)) {
rcu_read_lock();
err = bpf_fd_array_map_update_elem(map, f.file, key, value,
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,
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,
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, flags);
} else {
rcu_read_lock();
err = map->ops->map_update_elem(map, key, value, flags);
rcu_read_unlock();
}
bpf_enable_instrumentation();
maybe_wait_bpf_programs(map);
return err;
}
static int bpf_map_copy_value(struct bpf_map *map, void *key, void *value,
__u64 flags)
{
void *ptr;
int err;
if (bpf_map_is_dev_bound(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_copy(map, key, value);
} 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) {
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, since value wasn't zero inited */
check_and_init_map_lock(map, value);
}
rcu_read_unlock();
}
bpf_enable_instrumentation();
maybe_wait_bpf_programs(map);
return err;
}
static void *__bpf_map_area_alloc(u64 size, int numa_node, bool mmapable)
{
/* 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.
*/
const gfp_t flags = __GFP_NOWARN | __GFP_ZERO;
void *area;
if (size >= SIZE_MAX)
return NULL;
/* kmalloc()'ed memory can't be mmap()'ed */
if (!mmapable && size <= (PAGE_SIZE << PAGE_ALLOC_COSTLY_ORDER)) {
area = kmalloc_node(size, GFP_USER | __GFP_NORETRY | flags,
numa_node);
if (area != NULL)
return area;
}
if (mmapable) {
BUG_ON(!PAGE_ALIGNED(size));
return vmalloc_user_node_flags(size, numa_node, GFP_KERNEL |
__GFP_RETRY_MAYFAIL | flags);
}
return __vmalloc_node_flags_caller(size, numa_node,
GFP_KERNEL | __GFP_RETRY_MAYFAIL |
flags, __builtin_return_address(0));
}
void *bpf_map_area_alloc(u64 size, int numa_node)
{
return __bpf_map_area_alloc(size, numa_node, false);
}
void *bpf_map_area_mmapable_alloc(u64 size, int numa_node)
{
return __bpf_map_area_alloc(size, numa_node, true);
}
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_init_from_attr(struct bpf_map *map, union bpf_attr *attr)
{
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);
}
static int bpf_charge_memlock(struct user_struct *user, u32 pages)
{
unsigned long memlock_limit = rlimit(RLIMIT_MEMLOCK) >> PAGE_SHIFT;
if (atomic_long_add_return(pages, &user->locked_vm) > memlock_limit) {
atomic_long_sub(pages, &user->locked_vm);
return -EPERM;
}
return 0;
}
static void bpf_uncharge_memlock(struct user_struct *user, u32 pages)
{
if (user)
atomic_long_sub(pages, &user->locked_vm);
}
int bpf_map_charge_init(struct bpf_map_memory *mem, u64 size)
{
u32 pages = round_up(size, PAGE_SIZE) >> PAGE_SHIFT;
struct user_struct *user;
int ret;
if (size >= U32_MAX - PAGE_SIZE)
return -E2BIG;
user = get_current_user();
ret = bpf_charge_memlock(user, pages);
if (ret) {
free_uid(user);
return ret;
}
mem->pages = pages;
mem->user = user;
return 0;
}
void bpf_map_charge_finish(struct bpf_map_memory *mem)
{
bpf_uncharge_memlock(mem->user, mem->pages);
free_uid(mem->user);
}
void bpf_map_charge_move(struct bpf_map_memory *dst,
struct bpf_map_memory *src)
{
*dst = *src;
/* Make sure src will not be used for the redundant uncharging. */
memset(src, 0, sizeof(struct bpf_map_memory));
}
int bpf_map_charge_memlock(struct bpf_map *map, u32 pages)
{
int ret;
ret = bpf_charge_memlock(map->memory.user, pages);
if (ret)
return ret;
map->memory.pages += pages;
return ret;
}
void bpf_map_uncharge_memlock(struct bpf_map *map, u32 pages)
{
bpf_uncharge_memlock(map->memory.user, pages);
map->memory.pages -= pages;
}
static int bpf_map_alloc_id(struct bpf_map *map)
{
int id;
idr_preload(GFP_KERNEL);
spin_lock_bh(&map_idr_lock);
id = idr_alloc_cyclic(&map_idr, map, 1, INT_MAX, GFP_ATOMIC);
if (id > 0)
map->id = id;
spin_unlock_bh(&map_idr_lock);
idr_preload_end();
if (WARN_ON_ONCE(!id))
return -ENOSPC;
return id > 0 ? 0 : id;
}
void bpf_map_free_id(struct bpf_map *map, bool do_idr_lock)
{
unsigned long flags;
/* Offloaded maps are removed from the IDR store when their device
* disappears - even if someone holds an fd to them they are unusable,
* the memory is gone, all ops will fail; they are simply waiting for
* refcnt to drop to be freed.
*/
if (!map->id)
return;
if (do_idr_lock)
spin_lock_irqsave(&map_idr_lock, flags);
else
__acquire(&map_idr_lock);
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);
}
/* called from workqueue */
static void bpf_map_free_deferred(struct work_struct *work)
{
struct bpf_map *map = container_of(work, struct bpf_map, work);
struct bpf_map_memory mem;
bpf_map_charge_move(&mem, &map->memory);
security_bpf_map_free(map);
/* implementation dependent freeing */
map->ops->map_free(map);
bpf_map_charge_finish(&mem);
}
static void bpf_map_put_uref(struct bpf_map *map)
{
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)
{
if (atomic64_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);
}
}
void bpf_map_put(struct bpf_map *map)
{
__bpf_map_put(map, true);
}
EXPORT_SYMBOL_GPL(bpf_map_put);
void bpf_map_put_with_uref(struct bpf_map *map)
{
bpf_map_put_uref(map);
bpf_map_put(map);
}
static int bpf_map_release(struct inode *inode, struct file *filp)
{
struct bpf_map *map = filp->private_data;
if (map->ops->map_release)
map->ops->map_release(map, filp);
bpf_map_put_with_uref(map);
return 0;
}
static fmode_t map_get_sys_perms(struct bpf_map *map, struct fd f)
{
fmode_t mode = f.file->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
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 type = 0, jited = 0;
if (map->map_type == BPF_MAP_TYPE_PROG_ARRAY) {
array = container_of(map, struct bpf_array, map);
type = array->aux->type;
jited = array->aux->jited;
}
seq_printf(m,
"map_type:\t%u\n"
"key_size:\t%u\n"
"value_size:\t%u\n"
"max_entries:\t%u\n"
"map_flags:\t%#x\n"
"memlock:\t%llu\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->memory.pages * 1ULL << PAGE_SHIFT,
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
static ssize_t bpf_dummy_read(struct file *filp, char __user *buf, size_t siz,
loff_t *ppos)
{
/* We need this handler such that alloc_file() enables
* f_mode with FMODE_CAN_READ.
*/
return -EINVAL;
}
static ssize_t bpf_dummy_write(struct file *filp, const char __user *buf,
size_t siz, loff_t *ppos)
{
/* We need this handler such that alloc_file() enables
* f_mode with FMODE_CAN_WRITE.
*/
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) {
mutex_lock(&map->freeze_mutex);
map->writecnt++;
mutex_unlock(&map->freeze_mutex);
}
}
/* 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) {
mutex_lock(&map->freeze_mutex);
map->writecnt--;
mutex_unlock(&map->freeze_mutex);
}
}
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;
if (!map->ops->map_mmap || map_value_has_spin_lock(map))
return -ENOTSUPP;
if (!(vma->vm_flags & VM_SHARED))
return -EINVAL;
mutex_lock(&map->freeze_mutex);
if ((vma->vm_flags & VM_WRITE) && map->frozen) {
err = -EPERM;
goto out;
}
/* set default open/close callbacks */
vma->vm_ops = &bpf_map_default_vmops;
vma->vm_private_data = map;
vma->vm_flags &= ~VM_MAYEXEC;
if (!(vma->vm_flags & VM_WRITE))
/* disallow re-mapping with PROT_WRITE */
vma->vm_flags &= ~VM_MAYWRITE;
err = map->ops->map_mmap(map, vma);
if (err)
goto out;
if (vma->vm_flags & VM_MAYWRITE)
map->writecnt++;
out:
mutex_unlock(&map->freeze_mutex);
return err;
}
const struct file_operations bpf_map_fops = {
#ifdef CONFIG_PROC_FS
.show_fdinfo = bpf_map_show_fdinfo,
#endif
.release = bpf_map_release,
.read = bpf_dummy_read,
.write = bpf_dummy_write,
.mmap = bpf_map_mmap,
};
int bpf_map_new_fd(struct bpf_map *map, int flags)
{
int ret;
ret = security_bpf_map(map, OPEN_FMODE(flags));
if (ret < 0)
return ret;
return anon_inode_getfd("bpf-map", &bpf_map_fops, map,
flags | O_CLOEXEC);
}
int bpf_get_file_flag(int flags)
{
if ((flags & BPF_F_RDONLY) && (flags & BPF_F_WRONLY))
return -EINVAL;
if (flags & BPF_F_RDONLY)
return O_RDONLY;
if (flags & BPF_F_WRONLY)
return O_WRONLY;
return O_RDWR;
}
/* helper macro to check that unused fields 'union bpf_attr' are zero */
#define CHECK_ATTR(CMD) \
memchr_inv((void *) &attr->CMD##_LAST_FIELD + \
sizeof(attr->CMD##_LAST_FIELD), 0, \
sizeof(*attr) - \
offsetof(union bpf_attr, CMD##_LAST_FIELD) - \
sizeof(attr->CMD##_LAST_FIELD)) != NULL
/* dst and src must have at least "size" number of bytes.
* Return strlen on success and < 0 on error.
*/
int bpf_obj_name_cpy(char *dst, const char *src, unsigned int size)
{
const char *end = src + size;
const char *orig_src = src;
memset(dst, 0, size);
/* Copy all isalnum(), '_' and '.' chars. */
while (src < end && *src) {
if (!isalnum(*src) &&
*src != '_' && *src != '.')
return -EINVAL;
*dst++ = *src++;
}
/* No '\0' found in "size" number of bytes */
if (src == end)
return -EINVAL;
return src - orig_src;
}
int map_check_no_btf(const struct bpf_map *map,
const struct btf *btf,
const struct btf_type *key_type,
const struct btf_type *value_type)
{
return -ENOTSUPP;
}
static int map_check_btf(struct bpf_map *map, 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;
/* 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;
map->spin_lock_off = btf_find_spin_lock(btf, value_type);
if (map_value_has_spin_lock(map)) {
if (map->map_flags & BPF_F_RDONLY_PROG)
return -EACCES;
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)
return -ENOTSUPP;
if (map->spin_lock_off + sizeof(struct bpf_spin_lock) >
map->value_size) {
WARN_ONCE(1,
"verifier bug spin_lock_off %d value_size %d\n",
map->spin_lock_off, map->value_size);
return -EFAULT;
}
}
if (map->ops->map_check_btf)
ret = map->ops->map_check_btf(map, btf, key_type, value_type);
return ret;
}
#define BPF_MAP_CREATE_LAST_FIELD btf_vmlinux_value_type_id
/* called via syscall */
static int map_create(union bpf_attr *attr)
{
int numa_node = bpf_map_attr_numa_node(attr);
struct bpf_map_memory mem;
struct bpf_map *map;
int f_flags;
int err;
err = CHECK_ATTR(BPF_MAP_CREATE);
if (err)
return -EINVAL;
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;
}
f_flags = bpf_get_file_flag(attr->map_flags);
if (f_flags < 0)
return f_flags;
if (numa_node != NUMA_NO_NODE &&
((unsigned int)numa_node >= nr_node_ids ||
!node_online(numa_node)))
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,
sizeof(attr->map_name));
if (err < 0)
goto free_map;
atomic64_set(&map->refcnt, 1);
atomic64_set(&map->usercnt, 1);
mutex_init(&map->freeze_mutex);
map->spin_lock_off = -EINVAL;
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;
}
map->btf = btf;
if (attr->btf_value_type_id) {
err = map_check_btf(map, 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;
err = bpf_map_alloc_id(map);
if (err)
goto free_map_sec;
err = bpf_map_new_fd(map, f_flags);
if (err < 0) {
/* failed to allocate fd.
* 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_with_uref(map);
return err;
}
return err;
free_map_sec:
security_bpf_map_free(map);
free_map:
btf_put(map->btf);
bpf_map_charge_move(&mem, &map->memory);
map->ops->map_free(map);
bpf_map_charge_finish(&mem);
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)
{
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;
}
void bpf_map_inc(struct bpf_map *map)
{
atomic64_inc(&map->refcnt);
}
EXPORT_SYMBOL_GPL(bpf_map_inc);
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_get(u32 ufd)
{
struct fd f = fdget(ufd);
struct bpf_map *map;
map = __bpf_map_get(f);
if (IS_ERR(map))
return map;
bpf_map_inc(map);
fdput(f);
return map;
}
struct bpf_map *bpf_map_get_with_uref(u32 ufd)
{
struct fd f = fdget(ufd);
struct bpf_map *map;
map = __bpf_map_get(f);
if (IS_ERR(map))
return map;
bpf_map_inc_with_uref(map);
fdput(f);
return map;
}
/* map_idr_lock should have been held */
static struct bpf_map *__bpf_map_inc_not_zero(struct bpf_map *map, bool uref)
{
int refold;
refold = atomic64_fetch_add_unless(&map->refcnt, 1, 0);
if (!refold)
return ERR_PTR(-ENOENT);
if (uref)
atomic64_inc(&map->usercnt);
return map;
}
struct bpf_map *bpf_map_inc_not_zero(struct bpf_map *map)
{
spin_lock_bh(&map_idr_lock);
map = __bpf_map_inc_not_zero(map, false);
spin_unlock_bh(&map_idr_lock);
return map;
}
EXPORT_SYMBOL_GPL(bpf_map_inc_not_zero);
int __weak bpf_stackmap_copy(struct bpf_map *map, void *key, void *value)
{
return -ENOTSUPP;
}
static void *__bpf_copy_key(void __user *ukey, u64 key_size)
{
if (key_size)
return memdup_user(ukey, key_size);
if (ukey)
return ERR_PTR(-EINVAL);
return NULL;
}
/* last field in 'union bpf_attr' used by this command */
#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;
u32 value_size;
struct fd f;
int err;
if (CHECK_ATTR(BPF_MAP_LOOKUP_ELEM))
return -EINVAL;
if (attr->flags & ~BPF_F_LOCK)
return -EINVAL;
f = fdget(ufd);
map = __bpf_map_get(f);
if (IS_ERR(map))
return PTR_ERR(map);
if (!(map_get_sys_perms(map, f) & FMODE_CAN_READ)) {
err = -EPERM;
goto err_put;
}
if ((attr->flags & BPF_F_LOCK) &&
!map_value_has_spin_lock(map)) {
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 = bpf_map_value_size(map);
err = -ENOMEM;
value = kmalloc(value_size, GFP_USER | __GFP_NOWARN);
if (!value)
goto free_key;
err = bpf_map_copy_value(map, key, value, attr->flags);
if (err)
goto free_value;
err = -EFAULT;
if (copy_to_user(uvalue, value, value_size) != 0)
goto free_value;
err = 0;
free_value:
kfree(value);
free_key:
kfree(key);
err_put:
fdput(f);
return err;
}
#define BPF_MAP_UPDATE_ELEM_LAST_FIELD flags
static int map_update_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_UPDATE_ELEM))
return -EINVAL;
f = fdget(ufd);
map = __bpf_map_get(f);
if (IS_ERR(map))
return PTR_ERR(map);
if (!(map_get_sys_perms(map, f) & FMODE_CAN_WRITE)) {
err = -EPERM;
goto err_put;
}
if ((attr->flags & BPF_F_LOCK) &&
!map_value_has_spin_lock(map)) {
err = -EINVAL;
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)
goto free_key;
err = -EFAULT;
if (copy_from_user(value, uvalue, value_size) != 0)
goto free_value;
err = bpf_map_update_value(map, f, key, value, attr->flags);
free_value:
kfree(value);
free_key:
kfree(key);
err_put:
fdput(f);
return err;
}
#define BPF_MAP_DELETE_ELEM_LAST_FIELD key
static int map_delete_elem(union bpf_attr *attr)
{
void __user *ukey = u64_to_user_ptr(attr->key);
int ufd = attr->map_fd;
struct bpf_map *map;
struct fd f;
void *key;
int err;
if (CHECK_ATTR(BPF_MAP_DELETE_ELEM))
return -EINVAL;
f = fdget(ufd);
map = __bpf_map_get(f);
if (IS_ERR(map))
return PTR_ERR(map);
if (!(map_get_sys_perms(map, f) & FMODE_CAN_WRITE)) {
err = -EPERM;
goto err_put;
}
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)) {
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;
}
bpf_disable_instrumentation();
rcu_read_lock();
err = map->ops->map_delete_elem(map, key);
rcu_read_unlock();
bpf_enable_instrumentation();
maybe_wait_bpf_programs(map);
out:
kfree(key);
err_put:
fdput(f);
return err;
}
/* last field in 'union bpf_attr' used by this command */
#define BPF_MAP_GET_NEXT_KEY_LAST_FIELD next_key
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);
map = __bpf_map_get(f);
if (IS_ERR(map))
return PTR_ERR(map);
if (!(map_get_sys_perms(map, f) & FMODE_CAN_READ)) {
err = -EPERM;
goto err_put;
}
if (ukey) {
key = __bpf_copy_key(ukey, map->key_size);
if (IS_ERR(key)) {
err = PTR_ERR(key);
goto err_put;
}
} else {
key = NULL;
}
err = -ENOMEM;
next_key = kmalloc(map->key_size, GFP_USER);
if (!next_key)
goto free_key;
if (bpf_map_is_dev_bound(map)) {
err = bpf_map_offload_get_next_key(map, key, next_key);
goto out;
}
rcu_read_lock();
err = map->ops->map_get_next_key(map, key, next_key);
rcu_read_unlock();
out:
if (err)
goto free_next_key;
err = -EFAULT;
if (copy_to_user(unext_key, next_key, map->key_size) != 0)
goto free_next_key;
err = 0;
free_next_key:
kfree(next_key);
free_key:
kfree(key);
err_put:
fdput(f);
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) &&
!map_value_has_spin_lock(map)) {
return -EINVAL;
}
max_count = attr->batch.count;
if (!max_count)
return 0;
key = kmalloc(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_dev_bound(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();
maybe_wait_bpf_programs(map);
if (err)
break;
}
if (copy_to_user(&uattr->batch.count, &cp, sizeof(cp)))
err = -EFAULT;
kfree(key);
return err;
}
int generic_map_update_batch(struct bpf_map *map,
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;
int ufd = attr->map_fd;
void *key, *value;
struct fd f;
int err = 0;
f = fdget(ufd);
if (attr->batch.elem_flags & ~BPF_F_LOCK)
return -EINVAL;
if ((attr->batch.elem_flags & BPF_F_LOCK) &&
!map_value_has_spin_lock(map)) {
return -EINVAL;
}
value_size = bpf_map_value_size(map);
max_count = attr->batch.count;
if (!max_count)
return 0;
key = kmalloc(map->key_size, GFP_USER | __GFP_NOWARN);
if (!key)
return -ENOMEM;
value = kmalloc(value_size, GFP_USER | __GFP_NOWARN);
if (!value) {
kfree(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, f, key, value,
attr->batch.elem_flags);
if (err)
break;
}
if (copy_to_user(&uattr->batch.count, &cp, sizeof(cp)))
err = -EFAULT;
kfree(value);
kfree(key);
return err;
}
#define MAP_LOOKUP_RETRIES 3
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;
int err, retry = MAP_LOOKUP_RETRIES;
u32 value_size, cp, max_count;
if (attr->batch.elem_flags & ~BPF_F_LOCK)
return -EINVAL;
if ((attr->batch.elem_flags & BPF_F_LOCK) &&
!map_value_has_spin_lock(map))
return -EINVAL;
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 = kmalloc(map->key_size, GFP_USER | __GFP_NOWARN);
if (!buf_prevkey)
return -ENOMEM;
buf = kmalloc(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) {
if (retry) {
retry--;
continue;
}
err = -EINTR;
break;
}
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;
}
if (!prev_key)
prev_key = buf_prevkey;
swap(prev_key, key);
retry = MAP_LOOKUP_RETRIES;
cp++;
}
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:
kfree(buf_prevkey);
kfree(buf);
return err;
}
#define BPF_MAP_LOOKUP_AND_DELETE_ELEM_LAST_FIELD value
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);
map = __bpf_map_get(f);
if (IS_ERR(map))
return PTR_ERR(map);
if (!(map_get_sys_perms(map, f) & FMODE_CAN_WRITE)) {
err = -EPERM;
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;
err = -ENOMEM;
value = kmalloc(value_size, GFP_USER | __GFP_NOWARN);
if (!value)
goto free_key;
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;
}
if (err)
goto free_value;
if (copy_to_user(uvalue, value, value_size) != 0)
goto free_value;
err = 0;
free_value:
kfree(value);
free_key:
kfree(key);
err_put:
fdput(f);
return err;
}
#define BPF_MAP_FREEZE_LAST_FIELD map_fd
static int map_freeze(const union bpf_attr *attr)
{
int err = 0, ufd = attr->map_fd;
struct bpf_map *map;
struct fd f;
if (CHECK_ATTR(BPF_MAP_FREEZE))
return -EINVAL;
f = fdget(ufd);
map = __bpf_map_get(f);
if (IS_ERR(map))
return PTR_ERR(map);
if (map->map_type == BPF_MAP_TYPE_STRUCT_OPS) {
fdput(f);
return -ENOTSUPP;
}
mutex_lock(&map->freeze_mutex);
if (map->writecnt) {
err = -EBUSY;
goto err_put;
}
if (READ_ONCE(map->frozen)) {
err = -EBUSY;
goto err_put;
}
if (!capable(CAP_SYS_ADMIN)) {
err = -EPERM;
goto err_put;
}
WRITE_ONCE(map->frozen, true);
err_put:
mutex_unlock(&map->freeze_mutex);
fdput(f);
return err;
}
static const struct bpf_prog_ops * const bpf_prog_types[] = {
#define BPF_PROG_TYPE(_id, _name, prog_ctx_type, kern_ctx_type) \
[_id] = & _name ## _prog_ops,
#define BPF_MAP_TYPE(_id, _ops)
#include <linux/bpf_types.h>
#undef BPF_PROG_TYPE
#undef BPF_MAP_TYPE
};
static int find_prog_type(enum bpf_prog_type type, struct bpf_prog *prog)
{
const struct bpf_prog_ops *ops;
if (type >= ARRAY_SIZE(bpf_prog_types))
return -EINVAL;
type = array_index_nospec(type, ARRAY_SIZE(bpf_prog_types));
ops = bpf_prog_types[type];
if (!ops)
return -EINVAL;
if (!bpf_prog_is_dev_bound(prog->aux))
prog->aux->ops = ops;
else
prog->aux->ops = &bpf_offload_prog_ops;
prog->type = type;
return 0;
}
enum bpf_audit {
BPF_AUDIT_LOAD,
BPF_AUDIT_UNLOAD,
BPF_AUDIT_MAX,
};
static const char * const bpf_audit_str[BPF_AUDIT_MAX] = {
[BPF_AUDIT_LOAD] = "LOAD",
[BPF_AUDIT_UNLOAD] = "UNLOAD",
};
static void bpf_audit_prog(const struct bpf_prog *prog, unsigned int op)
{
struct audit_context *ctx = NULL;
struct audit_buffer *ab;
if (WARN_ON_ONCE(op >= BPF_AUDIT_MAX))
return;
if (audit_enabled == AUDIT_OFF)
return;
if (op == BPF_AUDIT_LOAD)
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);
}
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;
}
prog->aux->user = user;
return 0;
}
static void bpf_prog_uncharge_memlock(struct bpf_prog *prog)
{
struct user_struct *user = prog->aux->user;
__bpf_prog_uncharge(user, prog->pages);
free_uid(user);
}
static int bpf_prog_alloc_id(struct bpf_prog *prog)
{
int id;
idr_preload(GFP_KERNEL);
spin_lock_bh(&prog_idr_lock);
id = idr_alloc_cyclic(&prog_idr, prog, 1, INT_MAX, GFP_ATOMIC);
if (id > 0)
prog->aux->id = id;
spin_unlock_bh(&prog_idr_lock);
idr_preload_end();
/* id is in [1, INT_MAX) */
if (WARN_ON_ONCE(!id))
return -ENOSPC;
return id > 0 ? 0 : id;
}
void bpf_prog_free_id(struct bpf_prog *prog, bool do_idr_lock)
{
/* 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,
* simply waiting for refcnt to drop to be freed.
*/
if (!prog->aux->id)
return;
if (do_idr_lock)
spin_lock_bh(&prog_idr_lock);
else
__acquire(&prog_idr_lock);
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);
}
static void __bpf_prog_put_rcu(struct rcu_head *rcu)
{
struct bpf_prog_aux *aux = container_of(rcu, struct bpf_prog_aux, rcu);
kvfree(aux->func_info);
kfree(aux->func_info_aux);
bpf_prog_uncharge_memlock(aux->prog);
security_bpf_prog_free(aux);
bpf_prog_free(aux->prog);
}
static void __bpf_prog_put_noref(struct bpf_prog *prog, bool deferred)
{
bpf_prog_kallsyms_del_all(prog);
btf_put(prog->aux->btf);
bpf_prog_free_linfo(prog);
if (deferred)
call_rcu(&prog->aux->rcu, __bpf_prog_put_rcu);
else
__bpf_prog_put_rcu(&prog->aux->rcu);
}
static void __bpf_prog_put(struct bpf_prog *prog, bool do_idr_lock)
{
if (atomic64_dec_and_test(&prog->aux->refcnt)) {
perf_event_bpf_event(prog, PERF_BPF_EVENT_PROG_UNLOAD, 0);
bpf_audit_prog(prog, BPF_AUDIT_UNLOAD);
/* bpf_prog_free_id() must be called first */
bpf_prog_free_id(prog, do_idr_lock);
__bpf_prog_put_noref(prog, true);
}
}
void bpf_prog_put(struct bpf_prog *prog)
{
__bpf_prog_put(prog, true);
}
EXPORT_SYMBOL_GPL(bpf_prog_put);
static int bpf_prog_release(struct inode *inode, struct file *filp)
{
struct bpf_prog *prog = filp->private_data;
bpf_prog_put(prog);
return 0;
}
static void bpf_prog_get_stats(const struct bpf_prog *prog,
struct bpf_prog_stats *stats)
{
u64 nsecs = 0, cnt = 0;
int cpu;
for_each_possible_cpu(cpu) {
const struct bpf_prog_stats *st;
unsigned int start;
u64 tnsecs, tcnt;
st = per_cpu_ptr(prog->aux->stats, cpu);
do {
start = u64_stats_fetch_begin_irq(&st->syncp);
tnsecs = st->nsecs;
tcnt = st->cnt;
} while (u64_stats_fetch_retry_irq(&st->syncp, start));
nsecs += tnsecs;
cnt += tcnt;
}
stats->nsecs = nsecs;
stats->cnt = cnt;
}
#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_stats 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"
"run_time_ns:\t%llu\n"
"run_cnt:\t%llu\n",
prog->type,
prog->jited,
prog_tag,
prog->pages * 1ULL << PAGE_SHIFT,
prog->aux->id,
stats.nsecs,
stats.cnt);
}
#endif
const struct file_operations bpf_prog_fops = {
#ifdef CONFIG_PROC_FS
.show_fdinfo = bpf_prog_show_fdinfo,
#endif
.release = bpf_prog_release,
.read = bpf_dummy_read,
.write = bpf_dummy_write,
};
int bpf_prog_new_fd(struct bpf_prog *prog)
{
int ret;
ret = security_bpf_prog(prog);
if (ret < 0)
return ret;
return anon_inode_getfd("bpf-prog", &bpf_prog_fops, 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;
}
void bpf_prog_add(struct bpf_prog *prog, int i)
{
atomic64_add(i, &prog->aux->refcnt);
}
EXPORT_SYMBOL_GPL(bpf_prog_add);
void bpf_prog_sub(struct bpf_prog *prog, int i)
{
/* Only to be used for undoing previous bpf_prog_add() in some
* error path. We still know that another entity in our call
* path holds a reference to the program, thus atomic_sub() can
* be safely used in such cases!
*/
WARN_ON(atomic64_sub_return(i, &prog->aux->refcnt) == 0);
}
EXPORT_SYMBOL_GPL(bpf_prog_sub);
void bpf_prog_inc(struct bpf_prog *prog)
{
atomic64_inc(&prog->aux->refcnt);
}
EXPORT_SYMBOL_GPL(bpf_prog_inc);
/* prog_idr_lock should have been held */
struct bpf_prog *bpf_prog_inc_not_zero(struct bpf_prog *prog)
{
int refold;
refold = atomic64_fetch_add_unless(&prog->aux->refcnt, 1, 0);
if (!refold)
return ERR_PTR(-ENOENT);
return prog;
}
EXPORT_SYMBOL_GPL(bpf_prog_inc_not_zero);
bool bpf_prog_get_ok(struct bpf_prog *prog,
enum bpf_prog_type *attach_type, bool attach_drv)
{
/* not an attachment, just a refcount inc, always allow */
if (!attach_type)
return true;
if (prog->type != *attach_type)
return false;
if (bpf_prog_is_dev_bound(prog->aux) && !attach_drv)
return false;
return true;
}
static struct bpf_prog *__bpf_prog_get(u32 ufd, enum bpf_prog_type *attach_type,
bool attach_drv)
{
struct fd f = fdget(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;
}
bpf_prog_inc(prog);
out:
fdput(f);
return prog;
}
struct bpf_prog *bpf_prog_get(u32 ufd)
{
return __bpf_prog_get(ufd, NULL, false);
}
struct bpf_prog *bpf_prog_get_type_dev(u32 ufd, enum bpf_prog_type type,
bool attach_drv)
{
return __bpf_prog_get(ufd, &type, attach_drv);
}
EXPORT_SYMBOL_GPL(bpf_prog_get_type_dev);
/* Initially all BPF programs could be loaded w/o specifying
* expected_attach_type. Later for some of them specifying expected_attach_type
* at load time became required so that program could be validated properly.
* Programs of types that are allowed to be loaded both w/ and w/o (for
* backward compatibility) expected_attach_type, should have the default attach
* type assigned to expected_attach_type for the latter case, so that it can be
* validated later at attach time.
*
* bpf_prog_load_fixup_attach_type() sets expected_attach_type in @attr if
* prog type requires it but has some attach types that have to be backward
* compatible.
*/
static void bpf_prog_load_fixup_attach_type(union bpf_attr *attr)
{
switch (attr->prog_type) {
case BPF_PROG_TYPE_CGROUP_SOCK:
/* Unfortunately BPF_ATTACH_TYPE_UNSPEC enumeration doesn't
* exist so checking for non-zero is the way to go here.
*/
if (!attr->expected_attach_type)
attr->expected_attach_type =
BPF_CGROUP_INET_SOCK_CREATE;
break;
}
}
static int
bpf_prog_load_check_attach(enum bpf_prog_type prog_type,
enum bpf_attach_type expected_attach_type,
u32 btf_id, u32 prog_fd)
{
if (btf_id) {
if (btf_id > BTF_MAX_TYPE)
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 (prog_fd && 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_INET4_POST_BIND:
case BPF_CGROUP_INET6_POST_BIND:
return 0;
default:
return -EINVAL;
}
case BPF_PROG_TYPE_CGROUP_SOCK_ADDR:
switch (expected_attach_type) {
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:
case BPF_CGROUP_UDP4_RECVMSG:
case BPF_CGROUP_UDP6_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_EXT:
if (expected_attach_type)
return -EINVAL;
/* fallthrough */
default:
return 0;
}
}
/* last field in 'union bpf_attr' used by this command */
#define BPF_PROG_LOAD_LAST_FIELD attach_prog_fd
static int bpf_prog_load(union bpf_attr *attr, union bpf_attr __user *uattr)
{
enum bpf_prog_type type = attr->prog_type;
struct bpf_prog *prog;
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 |
BPF_F_TEST_STATE_FREQ |
BPF_F_TEST_RND_HI32))
return -EINVAL;
if (!IS_ENABLED(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) &&
(attr->prog_flags & BPF_F_ANY_ALIGNMENT) &&
!capable(CAP_SYS_ADMIN))
return -EPERM;
/* 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;
/* eBPF programs must be GPL compatible to use GPL-ed functions */
is_gpl = license_is_gpl_compatible(license);
if (attr->insn_cnt == 0 ||
attr->insn_cnt > (capable(CAP_SYS_ADMIN) ? BPF_COMPLEXITY_LIMIT_INSNS : BPF_MAXINSNS))
return -E2BIG;
if (type != BPF_PROG_TYPE_SOCKET_FILTER &&
type != BPF_PROG_TYPE_CGROUP_SKB &&
!capable(CAP_SYS_ADMIN))
return -EPERM;
bpf_prog_load_fixup_attach_type(attr);
if (bpf_prog_load_check_attach(type, attr->expected_attach_type,
attr->attach_btf_id,
attr->attach_prog_fd))
return -EINVAL;
/* plain bpf_prog allocation */
prog = bpf_prog_alloc(bpf_prog_size(attr->insn_cnt), GFP_USER);
if (!prog)
return -ENOMEM;
prog->expected_attach_type = attr->expected_attach_type;
prog->aux->attach_btf_id = attr->attach_btf_id;
if (attr->attach_prog_fd) {
struct bpf_prog *tgt_prog;
tgt_prog = bpf_prog_get(attr->attach_prog_fd);
if (IS_ERR(tgt_prog)) {
err = PTR_ERR(tgt_prog);
goto free_prog_nouncharge;
}
prog->aux->linked_prog = tgt_prog;
}
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->len = attr->insn_cnt;
err = -EFAULT;
if (copy_from_user(prog->insns, u64_to_user_ptr(attr->insns),
bpf_prog_insn_size(prog)) != 0)
goto free_prog;
prog->orig_prog = NULL;
prog->jited = 0;
atomic64_set(&prog->aux->refcnt, 1);
prog->gpl_compatible = is_gpl ? 1 : 0;
if (bpf_prog_is_dev_bound(prog->aux)) {
err = bpf_prog_offload_init(prog, attr);
if (err)
goto free_prog;
}
/* 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_boottime_ns();
err = bpf_obj_name_cpy(prog->aux->name, attr->prog_name,
sizeof(attr->prog_name));
if (err < 0)
goto free_prog;
/* run eBPF verifier */
err = bpf_check(&prog, attr, uattr);
if (err < 0)
goto free_used_maps;
prog = bpf_prog_select_runtime(prog, &err);
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)
bpf_prog_put(prog);
return err;
free_used_maps:
/* 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->func_cnt);
return err;
free_prog:
bpf_prog_uncharge_memlock(prog);
free_prog_sec:
security_bpf_prog_free(prog->aux);
free_prog_nouncharge:
bpf_prog_free(prog);
return err;
}
#define BPF_OBJ_LAST_FIELD file_flags
static int bpf_obj_pin(const union bpf_attr *attr)
{
if (CHECK_ATTR(BPF_OBJ) || attr->file_flags != 0)
return -EINVAL;
return bpf_obj_pin_user(attr->bpf_fd, u64_to_user_ptr(attr->pathname));
}
static int bpf_obj_get(const union bpf_attr *attr)
{
if (CHECK_ATTR(BPF_OBJ) || attr->bpf_fd != 0 ||
attr->file_flags & ~BPF_OBJ_FLAG_MASK)
return -EINVAL;
return bpf_obj_get_user(u64_to_user_ptr(attr->pathname),
attr->file_flags);
}
void bpf_link_init(struct bpf_link *link, const struct bpf_link_ops *ops,
struct bpf_prog *prog)
{
atomic64_set(&link->refcnt, 1);
link->ops = ops;
link->prog = prog;
}
/* 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 manages marking bpf_link as
* defunct, releases anon_inode file and puts reserved FD.
*/
void bpf_link_cleanup(struct bpf_link *link, struct file *link_file,
int link_fd)
{
link->prog = NULL;
fput(link_file);
put_unused_fd(link_fd);
}
void bpf_link_inc(struct bpf_link *link)
{
atomic64_inc(&link->refcnt);
}
/* bpf_link_free is guaranteed to be called from process context */
static void bpf_link_free(struct bpf_link *link)
{
if (link->prog) {
/* detach BPF program, clean up used resources */
link->ops->release(link);
bpf_prog_put(link->prog);
}
/* free bpf_link and its containing memory */
link->ops->dealloc(link);
}
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 can be called from atomic context, but ensures that resources
* are freed from process context
*/
void bpf_link_put(struct bpf_link *link)
{
if (!atomic64_dec_and_test(&link->refcnt))
return;
if (in_atomic()) {
INIT_WORK(&link->work, bpf_link_put_deferred);
schedule_work(&link->work);
} else {
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(link);
return 0;
}
#ifdef CONFIG_PROC_FS
static const struct bpf_link_ops bpf_raw_tp_lops;
static const struct bpf_link_ops bpf_tracing_link_lops;
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;
char prog_tag[sizeof(prog->tag) * 2 + 1] = { };
const char *link_type;
if (link->ops == &bpf_raw_tp_lops)
link_type = "raw_tracepoint";
else if (link->ops == &bpf_tracing_link_lops)
link_type = "tracing";
#ifdef CONFIG_CGROUP_BPF
else if (link->ops == &bpf_cgroup_link_lops)
link_type = "cgroup";
#endif
else
link_type = "unknown";
bin2hex(prog_tag, prog->tag, sizeof(prog->tag));
seq_printf(m,
"link_type:\t%s\n"
"prog_tag:\t%s\n"
"prog_id:\t%u\n",
link_type,
prog_tag,
prog->aux->id);
}
#endif
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,
};
int bpf_link_new_fd(struct bpf_link *link)
{
return anon_inode_getfd("bpf-link", &bpf_link_fops, link, O_CLOEXEC);
}
/* Similar to bpf_link_new_fd, create anon_inode for given bpf_link, but
* instead of immediately installing fd in fdtable, just reserve it and
* return. Caller then need to either install it with fd_install(fd, file) or
* release with put_unused_fd(fd).
* This is useful for cases when bpf_link attachment/detachment are
* complicated and expensive operations and should be delayed until all the fd
* reservation and anon_inode creation succeeds.
*/
struct file *bpf_link_new_file(struct bpf_link *link, int *reserved_fd)
{
struct file *file;
int fd;
fd = get_unused_fd_flags(O_CLOEXEC);
if (fd < 0)
return ERR_PTR(fd);
file = anon_inode_getfile("bpf_link", &bpf_link_fops, link, O_CLOEXEC);
if (IS_ERR(file)) {
put_unused_fd(fd);
return file;
}
*reserved_fd = fd;
return file;
}
struct bpf_link *bpf_link_get_from_fd(u32 ufd)
{
struct fd f = fdget(ufd);
struct bpf_link *link;
if (!f.file)
return ERR_PTR(-EBADF);
if (f.file->f_op != &bpf_link_fops) {
fdput(f);
return ERR_PTR(-EINVAL);
}
link = f.file->private_data;
bpf_link_inc(link);
fdput(f);
return link;
}
struct bpf_tracing_link {
struct bpf_link link;
};
static void bpf_tracing_link_release(struct bpf_link *link)
{
WARN_ON_ONCE(bpf_trampoline_unlink_prog(link->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);
kfree(tr_link);
}
static const struct bpf_link_ops bpf_tracing_link_lops = {
.release = bpf_tracing_link_release,
.dealloc = bpf_tracing_link_dealloc,
};
static int bpf_tracing_prog_attach(struct bpf_prog *prog)
{
struct bpf_tracing_link *link;
struct file *link_file;
int link_fd, 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;
}
link = kzalloc(sizeof(*link), GFP_USER);
if (!link) {
err = -ENOMEM;
goto out_put_prog;
}
bpf_link_init(&link->link, &bpf_tracing_link_lops, prog);
link_file = bpf_link_new_file(&link->link, &link_fd);
if (IS_ERR(link_file)) {
kfree(link);
err = PTR_ERR(link_file);
goto out_put_prog;
}
err = bpf_trampoline_link_prog(prog);
if (err) {
bpf_link_cleanup(&link->link, link_file, link_fd);
goto out_put_prog;
}
fd_install(link_fd, link_file);
return link_fd;
out_put_prog:
bpf_prog_put(prog);
return err;
}
struct bpf_raw_tp_link {
struct bpf_link link;
struct bpf_raw_event_map *btp;
};
static void bpf_raw_tp_link_release(struct bpf_link *link)
{
struct bpf_raw_tp_link *raw_tp =
container_of(link, struct bpf_raw_tp_link, link);
bpf_probe_unregister(raw_tp->btp, raw_tp->link.prog);
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 const struct bpf_link_ops bpf_raw_tp_lops = {
.release = bpf_raw_tp_link_release,
.dealloc = bpf_raw_tp_link_dealloc,
};
#define BPF_RAW_TRACEPOINT_OPEN_LAST_FIELD raw_tracepoint.prog_fd
static int bpf_raw_tracepoint_open(const union bpf_attr *attr)
{
struct bpf_raw_tp_link *link;
struct bpf_raw_event_map *btp;
struct file *link_file;
struct bpf_prog *prog;
const char *tp_name;
char buf[128];
int link_fd, err;
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);
switch (prog->type) {
case BPF_PROG_TYPE_TRACING:
case BPF_PROG_TYPE_EXT:
case BPF_PROG_TYPE_LSM:
if (attr->raw_tracepoint.name) {
/* The attach point for this category of programs
* should be specified via btf_id during program load.
*/
err = -EINVAL;
goto out_put_prog;
}
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);
case BPF_PROG_TYPE_RAW_TRACEPOINT:
case BPF_PROG_TYPE_RAW_TRACEPOINT_WRITABLE:
if (strncpy_from_user(buf,
u64_to_user_ptr(attr->raw_tracepoint.name),
sizeof(buf) - 1) < 0) {
err = -EFAULT;
goto out_put_prog;
}
buf[sizeof(buf) - 1] = 0;
tp_name = buf;
break;
default:
err = -EINVAL;
goto out_put_prog;
}
btp = bpf_get_raw_tracepoint(tp_name);
if (!btp) {
err = -ENOENT;
goto out_put_prog;
}
link = kzalloc(sizeof(*link), GFP_USER);
if (!link) {
err = -ENOMEM;
goto out_put_btp;
}
bpf_link_init(&link->link, &bpf_raw_tp_lops, prog);
link->btp = btp;
link_file = bpf_link_new_file(&link->link, &link_fd);
if (IS_ERR(link_file)) {
kfree(link);
err = PTR_ERR(link_file);
goto out_put_btp;
}
err = bpf_probe_register(link->btp, prog);
if (err) {
bpf_link_cleanup(&link->link, link_file, link_fd);
goto out_put_btp;
}
fd_install(link_fd, link_file);
return link_fd;
out_put_btp:
bpf_put_raw_tracepoint(btp);
out_put_prog:
bpf_prog_put(prog);
return err;
}
static int bpf_prog_attach_check_attach_type(const struct bpf_prog *prog,
enum bpf_attach_type attach_type)
{
switch (prog->type) {
case BPF_PROG_TYPE_CGROUP_SOCK:
case BPF_PROG_TYPE_CGROUP_SOCK_ADDR:
case BPF_PROG_TYPE_CGROUP_SOCKOPT:
return attach_type == prog->expected_attach_type ? 0 : -EINVAL;
case BPF_PROG_TYPE_CGROUP_SKB:
return prog->enforce_expected_attach_type &&
prog->expected_attach_type != attach_type ?
-EINVAL : 0;
default:
return 0;
}
}
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:
return BPF_PROG_TYPE_CGROUP_SKB;
break;
case BPF_CGROUP_INET_SOCK_CREATE:
case BPF_CGROUP_INET4_POST_BIND:
case BPF_CGROUP_INET6_POST_BIND:
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_UDP4_SENDMSG:
case BPF_CGROUP_UDP6_SENDMSG:
case BPF_CGROUP_UDP4_RECVMSG:
case BPF_CGROUP_UDP6_RECVMSG:
return BPF_PROG_TYPE_CGROUP_SOCK_ADDR;
case BPF_CGROUP_SOCK_OPS:
return BPF_PROG_TYPE_SOCK_OPS;
case BPF_CGROUP_DEVICE:
return BPF_PROG_TYPE_CGROUP_DEVICE;
case BPF_SK_MSG_VERDICT:
return BPF_PROG_TYPE_SK_MSG;
case BPF_SK_SKB_STREAM_PARSER:
case BPF_SK_SKB_STREAM_VERDICT:
return BPF_PROG_TYPE_SK_SKB;
case BPF_LIRC_MODE2:
return BPF_PROG_TYPE_LIRC_MODE2;
case BPF_FLOW_DISSECTOR:
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;
default:
return BPF_PROG_TYPE_UNSPEC;
}
}
#define BPF_PROG_ATTACH_LAST_FIELD replace_bpf_fd
#define BPF_F_ATTACH_MASK \
(BPF_F_ALLOW_OVERRIDE | BPF_F_ALLOW_MULTI | BPF_F_REPLACE)
static int bpf_prog_attach(const union bpf_attr *attr)
{
enum bpf_prog_type ptype;
struct bpf_prog *prog;
int ret;
if (!capable(CAP_NET_ADMIN))
return -EPERM;
if (CHECK_ATTR(BPF_PROG_ATTACH))
return -EINVAL;
if (attr->attach_flags & ~BPF_F_ATTACH_MASK)
return -EINVAL;
ptype = attach_type_to_prog_type(attr->attach_type);
if (ptype == BPF_PROG_TYPE_UNSPEC)
return -EINVAL;
prog = bpf_prog_get_type(attr->attach_bpf_fd, ptype);
if (IS_ERR(prog))
return PTR_ERR(prog);
if (bpf_prog_attach_check_attach_type(prog, attr->attach_type)) {
bpf_prog_put(prog);
return -EINVAL;
}
switch (ptype) {
case BPF_PROG_TYPE_SK_SKB:
case BPF_PROG_TYPE_SK_MSG:
ret = sock_map_get_from_fd(attr, prog);
break;
case BPF_PROG_TYPE_LIRC_MODE2:
ret = lirc_prog_attach(attr, prog);
break;
case BPF_PROG_TYPE_FLOW_DISSECTOR:
ret = skb_flow_dissector_bpf_prog_attach(attr, prog);
break;
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:
ret = cgroup_bpf_prog_attach(attr, ptype, prog);
break;
default:
ret = -EINVAL;
}
if (ret)
bpf_prog_put(prog);
return ret;
}
#define BPF_PROG_DETACH_LAST_FIELD attach_type
static int bpf_prog_detach(const union bpf_attr *attr)
{
enum bpf_prog_type ptype;
if (!capable(CAP_NET_ADMIN))
return -EPERM;
if (CHECK_ATTR(BPF_PROG_DETACH))
return -EINVAL;
ptype = attach_type_to_prog_type(attr->attach_type);
switch (ptype) {
case BPF_PROG_TYPE_SK_MSG:
case BPF_PROG_TYPE_SK_SKB:
return sock_map_get_from_fd(attr, NULL);
case BPF_PROG_TYPE_LIRC_MODE2:
return lirc_prog_detach(attr);
case BPF_PROG_TYPE_FLOW_DISSECTOR:
return skb_flow_dissector_bpf_prog_detach(attr);
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 cgroup_bpf_prog_detach(attr, ptype);
default:
return -EINVAL;
}
}
#define BPF_PROG_QUERY_LAST_FIELD query.prog_cnt
static int bpf_prog_query(const union bpf_attr *attr,
union bpf_attr __user *uattr)
{
if (!capable(CAP_NET_ADMIN))
return -EPERM;
if (CHECK_ATTR(BPF_PROG_QUERY))
return -EINVAL;
if (attr->query.query_flags & ~BPF_F_QUERY_EFFECTIVE)
return -EINVAL;
switch (attr->query.attach_type) {
case BPF_CGROUP_INET_INGRESS:
case BPF_CGROUP_INET_EGRESS:
case BPF_CGROUP_INET_SOCK_CREATE:
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_UDP4_SENDMSG:
case BPF_CGROUP_UDP6_SENDMSG:
case BPF_CGROUP_UDP4_RECVMSG:
case BPF_CGROUP_UDP6_RECVMSG:
case BPF_CGROUP_SOCK_OPS:
case BPF_CGROUP_DEVICE:
case BPF_CGROUP_SYSCTL:
case BPF_CGROUP_GETSOCKOPT:
case BPF_CGROUP_SETSOCKOPT:
return cgroup_bpf_prog_query(attr, uattr);
case BPF_LIRC_MODE2:
return lirc_prog_query(attr, uattr);
case BPF_FLOW_DISSECTOR:
return skb_flow_dissector_prog_query(attr, uattr);
default:
return -EINVAL;
}
}
#define BPF_PROG_TEST_RUN_LAST_FIELD test.ctx_out
static int bpf_prog_test_run(const union bpf_attr *attr,
union bpf_attr __user *uattr)
{
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);
if (prog->aux->ops->test_run)
ret = prog->aux->ops->test_run(prog, attr, uattr);
bpf_prog_put(prog);
return ret;
}
#define BPF_OBJ_GET_NEXT_ID_LAST_FIELD next_id
static int bpf_obj_get_next_id(const union bpf_attr *attr,
union bpf_attr __user *uattr,
struct idr *idr,
spinlock_t *lock)
{
u32 next_id = attr->start_id;
int err = 0;
if (CHECK_ATTR(BPF_OBJ_GET_NEXT_ID) || next_id >= INT_MAX)
return -EINVAL;
if (!capable(CAP_SYS_ADMIN))
return -EPERM;
next_id++;
spin_lock_bh(lock);
if (!idr_get_next(idr, &next_id))
err = -ENOENT;
spin_unlock_bh(lock);
if (!err)
err = put_user(next_id, &uattr->next_id);
return err;
}
#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);
if (prog)
prog = bpf_prog_inc_not_zero(prog);
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);
fd = bpf_prog_new_fd(prog);
if (fd < 0)
bpf_prog_put(prog);
return fd;
}
#define BPF_MAP_GET_FD_BY_ID_LAST_FIELD open_flags
static int bpf_map_get_fd_by_id(const union bpf_attr *attr)
{
struct bpf_map *map;
u32 id = attr->map_id;
int f_flags;
int fd;
if (CHECK_ATTR(BPF_MAP_GET_FD_BY_ID) ||
attr->open_flags & ~BPF_OBJ_FLAG_MASK)
return -EINVAL;
if (!capable(CAP_SYS_ADMIN))
return -EPERM;
f_flags = bpf_get_file_flag(attr->open_flags);
if (f_flags < 0)
return f_flags;
spin_lock_bh(&map_idr_lock);
map = idr_find(&map_idr, id);
if (map)
map = __bpf_map_inc_not_zero(map, true);
else
map = ERR_PTR(-ENOENT);
spin_unlock_bh(&map_idr_lock);
if (IS_ERR(map))
return PTR_ERR(map);
fd = bpf_map_new_fd(map, f_flags);
if (fd < 0)
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, u32 *off,
u32 *type)
{
const struct bpf_map *map;
int i;
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;
return map;
}
if (!map->ops->map_direct_value_meta)
continue;
if (!map->ops->map_direct_value_meta(map, addr, off)) {
*type = BPF_PSEUDO_MAP_VALUE;
return map;
}
}
return NULL;
}
static struct bpf_insn *bpf_insn_prepare_dump(const struct bpf_prog *prog)
{
const struct bpf_map *map;
struct bpf_insn *insns;
u32 off, type;
u64 imm;
int i;
insns = kmemdup(prog->insnsi, bpf_prog_insn_size(prog),
GFP_USER);
if (!insns)
return insns;
for (i = 0; i < prog->len; i++) {
if (insns[i].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))
insns[i].code = BPF_JMP | BPF_CALL;
if (!bpf_dump_raw_ok())
insns[i].imm = 0;
continue;
}
if (insns[i].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, &off, &type);
if (map) {
insns[i].src_reg = type;
insns[i].imm = map->id;
insns[i + 1].imm = off;
continue;
}
}
return insns;
}
static int set_info_rec_size(struct bpf_prog_info *info)
{
/*
* Ensure info.*_rec_size is the same as kernel expected size
*
* or
*
* Only allow zero *_rec_size if both _rec_size and _cnt are
* zero. In this case, the kernel will set the expected
* _rec_size back to the info.
*/
if ((info->nr_func_info || info->func_info_rec_size) &&
info->func_info_rec_size != sizeof(struct bpf_func_info))
return -EINVAL;
if ((info->nr_line_info || info->line_info_rec_size) &&
info->line_info_rec_size != sizeof(struct bpf_line_info))
return -EINVAL;
if ((info->nr_jited_line_info || info->jited_line_info_rec_size) &&
info->jited_line_info_rec_size != sizeof(__u64))
return -EINVAL;
info->func_info_rec_size = sizeof(struct bpf_func_info);
info->line_info_rec_size = sizeof(struct bpf_line_info);
info->jited_line_info_rec_size = sizeof(__u64);
return 0;
}
static int bpf_prog_get_info_by_fd(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;
u32 info_len = attr->info.info_len;
struct bpf_prog_stats stats;
char __user *uinsns;
u32 ulen;
int err;
err = bpf_check_uarg_tail_zero(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 = prog->type;
info.id = prog->aux->id;
info.load_time = prog->aux->load_time;
info.created_by_uid = from_kuid_munged(current_user_ns(),
prog->aux->user->uid);
info.gpl_compatible = prog->gpl_compatible;
memcpy(info.tag, prog->tag, sizeof(prog->tag));
memcpy(info.name, prog->aux->name, sizeof(prog->aux->name));
ulen = info.nr_map_ids;
info.nr_map_ids = prog->aux->used_map_cnt;
ulen = min_t(u32, info.nr_map_ids, ulen);
if (ulen) {
u32 __user *user_map_ids = u64_to_user_ptr(info.map_ids);
u32 i;
for (i = 0; i < ulen; i++)
if (put_user(prog->aux->used_maps[i]->id,
&user_map_ids[i]))
return -EFAULT;
}
err = set_info_rec_size(&info);
if (err)
return err;
bpf_prog_get_stats(prog, &stats);
info.run_time_ns = stats.nsecs;
info.run_cnt = stats.cnt;
if (!capable(CAP_SYS_ADMIN)) {
info.jited_prog_len = 0;
info.xlated_prog_len = 0;
info.nr_jited_ksyms = 0;
info.nr_jited_func_lens = 0;
info.nr_func_info = 0;
info.nr_line_info = 0;
info.nr_jited_line_info = 0;
goto done;
}
ulen = info.xlated_prog_len;
info.xlated_prog_len = bpf_prog_insn_size(prog);
if (info.xlated_prog_len && ulen) {
struct bpf_insn *insns_sanitized;
bool fault;
if (prog->blinded && !bpf_dump_raw_ok()) {
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)) {
err = bpf_prog_offload_info_fill(&info, prog);
if (err)
return err;
goto done;
}
/* NOTE: the following code is supposed to be skipped for offload.
* bpf_prog_offload_info_fill() is the place to fill similar fields
* for offload.
*/
ulen = info.jited_prog_len;
if (prog->aux->func_cnt) {
u32 i;
info.jited_prog_len = 0;
for (i = 0; i < prog->aux->func_cnt; i++)
info.jited_prog_len += prog->aux->func[i]->jited_len;
} else {
info.jited_prog_len = prog->jited_len;
}
if (info.jited_prog_len && ulen) {
if (bpf_dump_raw_ok()) {
uinsns = u64_to_user_ptr(info.jited_prog_insns);
ulen = min_t(u32, info.jited_prog_len, ulen);
/* for multi-function programs, copy the JITed
* instructions for all the functions
*/
if (prog->aux->func_cnt) {
u32 len, free, i;
u8 *img;
free = ulen;
for (i = 0; i < prog->aux->func_cnt; i++) {
len = prog->aux->func[i]->jited_len;
len = min_t(u32, len, free);
img = (u8 *) prog->aux->func[i]->bpf_func;
if (copy_to_user(uinsns, img, len))
return -EFAULT;
uinsns += len;
free -= len;
if (!free)
break;
}
} else {
if (copy_to_user(uinsns, prog->bpf_func, ulen))
return -EFAULT;
}
} else {
info.jited_prog_insns = 0;
}
}
ulen = info.nr_jited_ksyms;
info.nr_jited_ksyms = prog->aux->func_cnt ? : 1;
if (ulen) {
if (bpf_dump_raw_ok()) {
unsigned long ksym_addr;
u64 __user *user_ksyms;
u32 i;
/* copy the address of the kernel symbol
* corresponding to each function
*/
ulen = min_t(u32, info.nr_jited_ksyms, ulen);
user_ksyms = u64_to_user_ptr(info.jited_ksyms);
if (prog->aux->func_cnt) {
for (i = 0; i < ulen; i++) {
ksym_addr = (unsigned long)
prog->aux->func[i]->bpf_func;
if (put_user((u64) ksym_addr,
&user_ksyms[i]))
return -EFAULT;
}
} else {
ksym_addr = (unsigned long) prog->bpf_func;
if (put_user((u64) ksym_addr, &user_ksyms[0]))
return -EFAULT;
}
} else {
info.jited_ksyms = 0;
}
}
ulen = info.nr_jited_func_lens;
info.nr_jited_func_lens = prog->aux->func_cnt ? : 1;
if (ulen) {
if (bpf_dump_raw_ok()) {
u32 __user *user_lens;
u32 func_len, i;
/* copy the JITed image lengths for each function */
ulen = min_t(u32, info.nr_jited_func_lens, ulen);
user_lens = u64_to_user_ptr(info.jited_func_lens);
if (prog->aux->func_cnt) {
for (i = 0; i < ulen; i++) {
func_len =
prog->aux->func[i]->jited_len;
if (put_user(func_len, &user_lens[i]))
return -EFAULT;
}
} else {
func_len = prog->jited_len;
if (put_user(func_len, &user_lens[0]))
return -EFAULT;
}
} else {
info.jited_func_lens = 0;
}
}
if (prog->aux->btf)
info.btf_id = btf_id(prog->aux->btf);
ulen = info.nr_func_info;
info.nr_func_info = prog->aux->func_info_cnt;
if (info.nr_func_info && ulen) {
char __user *user_finfo;
user_finfo = u64_to_user_ptr(info.func_info);
ulen = min_t(u32, info.nr_func_info, ulen);
if (copy_to_user(user_finfo, prog->aux->func_info,
info.func_info_rec_size * ulen))
return -EFAULT;
}
ulen = info.nr_line_info;
info.nr_line_info = prog->aux->nr_linfo;
if (info.nr_line_info && ulen) {
__u8 __user *user_linfo;
user_linfo = u64_to_user_ptr(info.line_info);
ulen = min_t(u32, info.nr_line_info, ulen);
if (copy_to_user(user_linfo, prog->aux->linfo,
info.line_info_rec_size * ulen))
return -EFAULT;
}
ulen = info.nr_jited_line_info;
if (prog->aux->jited_linfo)
info.nr_jited_line_info = prog->aux->nr_linfo;
else
info.nr_jited_line_info = 0;
if (info.nr_jited_line_info && ulen) {
if (bpf_dump_raw_ok()) {
__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]))
return -EFAULT;
}
} else {
info.jited_line_info = 0;
}
}
ulen = info.nr_prog_tags;
info.nr_prog_tags = prog->aux->func_cnt ? : 1;
if (ulen) {
__u8 __user (*user_prog_tags)[BPF_TAG_SIZE];
u32 i;
user_prog_tags = u64_to_user_ptr(info.prog_tags);
ulen = min_t(u32, info.nr_prog_tags, ulen);
if (prog->aux->func_cnt) {
for (i = 0; i < ulen; i++) {
if (copy_to_user(user_prog_tags[i],
prog->aux->func[i]->tag,
BPF_TAG_SIZE))
return -EFAULT;
}
} else {
if (copy_to_user(user_prog_tags[0],
prog->tag, BPF_TAG_SIZE))
return -EFAULT;
}
}
done:
if (copy_to_user(uinfo, &info, info_len) ||
put_user(info_len, &uattr->info.info_len))
return -EFAULT;
return 0;
}
static int bpf_map_get_info_by_fd(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;
u32 info_len = attr->info.info_len;
int err;
err = bpf_check_uarg_tail_zero(uinfo, sizeof(info), info_len);
if (err)
return err;
info_len = min_t(u32, sizeof(info), info_len);
memset(&info, 0, sizeof(info));
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;
memcpy(info.name, map->name, sizeof(map->name));
if (map->btf) {
info.btf_id = btf_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 (bpf_map_is_dev_bound(map)) {
err = bpf_map_offload_info_fill(&info, map);
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 bpf_btf_get_info_by_fd(struct btf *btf,
const union bpf_attr *attr,
union bpf_attr __user *uattr)
{
struct bpf_btf_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(uinfo, sizeof(*uinfo), info_len);
if (err)
return err;
return btf_get_info_by_fd(btf, 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)
return -EBADFD;
if (f.file->f_op == &bpf_prog_fops)
err = bpf_prog_get_info_by_fd(f.file->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,
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;
}
#define BPF_BTF_LOAD_LAST_FIELD btf_log_level
static int bpf_btf_load(const union bpf_attr *attr)
{
if (CHECK_ATTR(BPF_BTF_LOAD))
return -EINVAL;
if (!capable(CAP_SYS_ADMIN))
return -EPERM;
return btf_new_fd(attr);
}
#define BPF_BTF_GET_FD_BY_ID_LAST_FIELD btf_id
static int bpf_btf_get_fd_by_id(const union bpf_attr *attr)
{
if (CHECK_ATTR(BPF_BTF_GET_FD_BY_ID))
return -EINVAL;
if (!capable(CAP_SYS_ADMIN))
return -EPERM;
return btf_get_fd_by_id(attr->btf_id);
}
static int bpf_task_fd_query_copy(const union bpf_attr *attr,
union bpf_attr __user *uattr,
u32 prog_id, u32 fd_type,
const char *buf, u64 probe_offset,
u64 probe_addr)
{
char __user *ubuf = u64_to_user_ptr(attr->task_fd_query.buf);
u32 len = buf ? strlen(buf) : 0, input_len;
int err = 0;
if (put_user(len, &uattr->task_fd_query.buf_len))
return -EFAULT;
input_len = attr->task_fd_query.buf_len;
if (input_len && ubuf) {
if (!len) {
/* nothing to copy, just make ubuf NULL terminated */
char zero = '\0';
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;
}
}
if (put_user(prog_id, &uattr->task_fd_query.prog_id) ||
put_user(fd_type, &uattr->task_fd_query.fd_type) ||
put_user(probe_offset, &uattr->task_fd_query.probe_offset) ||
put_user(probe_addr, &uattr->task_fd_query.probe_addr))
return -EFAULT;
return err;
}
#define BPF_TASK_FD_QUERY_LAST_FIELD task_fd_query.probe_addr
static int bpf_task_fd_query(const union bpf_attr *attr,
union bpf_attr __user *uattr)
{
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;
if (CHECK_ATTR(BPF_TASK_FD_QUERY))
return -EINVAL;
if (!capable(CAP_SYS_ADMIN))
return -EPERM;
if (attr->task_fd_query.flags != 0)
return -EINVAL;
task = get_pid_task(find_vpid(pid), PIDTYPE_PID);
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);
if (!file)
err = -EBADF;
else
get_file(file);
spin_unlock(&files->file_lock);
put_files_struct(files);
if (err)
goto out;
if (file->f_op == &bpf_link_fops) {
struct bpf_link *link = file->private_data;
if (link->ops == &bpf_raw_tp_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->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);
if (!IS_ERR(event)) {
u64 probe_offset, probe_addr;
u32 prog_id, fd_type;
const char *buf;
err = bpf_get_perf_event_info(event, &prog_id, &fd_type,
&buf, &probe_offset,
&probe_addr);
if (!err)
err = bpf_task_fd_query_copy(attr, uattr, prog_id,
fd_type, buf,
probe_offset,
probe_addr);
goto put_file;
}
out_not_supp:
err = -ENOTSUPP;
put_file:
fput(file);
out:
return err;
}
#define BPF_MAP_BATCH_LAST_FIELD batch.flags
#define BPF_DO_BATCH(fn) \
do { \
if (!fn) { \
err = -ENOTSUPP; \
goto err_put; \
} \
err = fn(map, attr, uattr); \
} while (0)
static int bpf_map_do_batch(const union bpf_attr *attr,
union bpf_attr __user *uattr,
int cmd)
{
struct bpf_map *map;
int err, ufd;
struct fd f;
if (CHECK_ATTR(BPF_MAP_BATCH))
return -EINVAL;
ufd = attr->batch.map_fd;
f = fdget(ufd);
map = __bpf_map_get(f);
if (IS_ERR(map))
return PTR_ERR(map);
if ((cmd == BPF_MAP_LOOKUP_BATCH ||
cmd == BPF_MAP_LOOKUP_AND_DELETE_BATCH) &&
!(map_get_sys_perms(map, f) & FMODE_CAN_READ)) {
err = -EPERM;
goto err_put;
}
if (cmd != BPF_MAP_LOOKUP_BATCH &&
!(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);
else if (cmd == BPF_MAP_LOOKUP_AND_DELETE_BATCH)
BPF_DO_BATCH(map->ops->map_lookup_and_delete_batch);
else if (cmd == BPF_MAP_UPDATE_BATCH)
BPF_DO_BATCH(map->ops->map_update_batch);
else
BPF_DO_BATCH(map->ops->map_delete_batch);
err_put:
fdput(f);
return err;
}
#define BPF_LINK_CREATE_LAST_FIELD link_create.flags
static int link_create(union bpf_attr *attr)
{
enum bpf_prog_type ptype;
struct bpf_prog *prog;
int ret;
if (!capable(CAP_NET_ADMIN))
return -EPERM;
if (CHECK_ATTR(BPF_LINK_CREATE))
return -EINVAL;
ptype = attach_type_to_prog_type(attr->link_create.attach_type);
if (ptype == BPF_PROG_TYPE_UNSPEC)
return -EINVAL;
prog = bpf_prog_get_type(attr->link_create.prog_fd, ptype);
if (IS_ERR(prog))
return PTR_ERR(prog);
ret = bpf_prog_attach_check_attach_type(prog,
attr->link_create.attach_type);
if (ret)
goto err_out;
switch (ptype) {
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;
default:
ret = -EINVAL;
}
err_out:
if (ret < 0)
bpf_prog_put(prog);
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 (!capable(CAP_NET_ADMIN))
return -EPERM;
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);
new_prog = bpf_prog_get(attr->link_update.new_prog_fd);
if (IS_ERR(new_prog))
return PTR_ERR(new_prog);
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;
}
}
#ifdef CONFIG_CGROUP_BPF
if (link->ops == &bpf_cgroup_link_lops) {
ret = cgroup_bpf_replace(link, old_prog, new_prog);
goto out_put_progs;
}
#endif
ret = -EINVAL;
out_put_progs:
if (old_prog)
bpf_prog_put(old_prog);
if (ret)
bpf_prog_put(new_prog);
return ret;
}
SYSCALL_DEFINE3(bpf, int, cmd, union bpf_attr __user *, uattr, unsigned int, size)
{
union bpf_attr attr;
int err;
if (sysctl_unprivileged_bpf_disabled && !capable(CAP_SYS_ADMIN))
return -EPERM;
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) */
memset(&attr, 0, sizeof(attr));
if (copy_from_user(&attr, uattr, size) != 0)
return -EFAULT;
err = security_bpf(cmd, &attr, size);
if (err < 0)
return err;
switch (cmd) {
case BPF_MAP_CREATE:
err = map_create(&attr);
break;
case BPF_MAP_LOOKUP_ELEM:
err = map_lookup_elem(&attr);
break;
case BPF_MAP_UPDATE_ELEM:
err = map_update_elem(&attr);
break;
case BPF_MAP_DELETE_ELEM:
err = map_delete_elem(&attr);
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);
break;
case BPF_OBJ_PIN:
err = bpf_obj_pin(&attr);
break;
case BPF_OBJ_GET:
err = bpf_obj_get(&attr);
break;
case BPF_PROG_ATTACH:
err = bpf_prog_attach(&attr);
break;
case BPF_PROG_DETACH:
err = bpf_prog_detach(&attr);
break;
case BPF_PROG_QUERY:
err = bpf_prog_query(&attr, uattr);
break;
case BPF_PROG_TEST_RUN:
err = bpf_prog_test_run(&attr, uattr);
break;
case BPF_PROG_GET_NEXT_ID:
err = bpf_obj_get_next_id(&attr, uattr,
&prog_idr, &prog_idr_lock);
break;
case BPF_MAP_GET_NEXT_ID:
err = bpf_obj_get_next_id(&attr, uattr,
&map_idr, &map_idr_lock);
break;
case BPF_BTF_GET_NEXT_ID:
err = bpf_obj_get_next_id(&attr, uattr,
&btf_idr, &btf_idr_lock);
break;
case BPF_PROG_GET_FD_BY_ID:
err = bpf_prog_get_fd_by_id(&attr);
break;
case BPF_MAP_GET_FD_BY_ID:
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);
break;
case BPF_RAW_TRACEPOINT_OPEN:
err = bpf_raw_tracepoint_open(&attr);
break;
case BPF_BTF_LOAD:
err = bpf_btf_load(&attr);
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);
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, BPF_MAP_LOOKUP_BATCH);
break;
case BPF_MAP_LOOKUP_AND_DELETE_BATCH:
err = bpf_map_do_batch(&attr, uattr,
BPF_MAP_LOOKUP_AND_DELETE_BATCH);
break;
case BPF_MAP_UPDATE_BATCH:
err = bpf_map_do_batch(&attr, uattr, BPF_MAP_UPDATE_BATCH);
break;
case BPF_MAP_DELETE_BATCH:
err = bpf_map_do_batch(&attr, uattr, BPF_MAP_DELETE_BATCH);
break;
case BPF_LINK_CREATE:
err = link_create(&attr);
break;
case BPF_LINK_UPDATE:
err = link_update(&attr);
break;
default:
err = -EINVAL;
break;
}
return err;
}
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