// SPDX-License-Identifier: GPL-2.0-only
/* Copyright (c) 2011-2014 PLUMgrid, http://plumgrid.com
*/
#include <linux/bpf.h>
#include <linux/btf.h>
#include <linux/bpf-cgroup.h>
#include <linux/cgroup.h>
#include <linux/rcupdate.h>
#include <linux/random.h>
#include <linux/smp.h>
#include <linux/topology.h>
#include <linux/ktime.h>
#include <linux/sched.h>
#include <linux/uidgid.h>
#include <linux/filter.h>
#include <linux/ctype.h>
#include <linux/jiffies.h>
#include <linux/pid_namespace.h>
#include <linux/poison.h>
#include <linux/proc_ns.h>
#include <linux/sched/task.h>
#include <linux/security.h>
#include <linux/btf_ids.h>
#include <linux/bpf_mem_alloc.h>
#include <linux/kasan.h>
#include "../../lib/kstrtox.h"
/* If kernel subsystem is allowing eBPF programs to call this function,
* inside its own verifier_ops->get_func_proto() callback it should return
* bpf_map_lookup_elem_proto, so that verifier can properly check the arguments
*
* Different map implementations will rely on rcu in map methods
* lookup/update/delete, therefore eBPF programs must run under rcu lock
* if program is allowed to access maps, so check rcu_read_lock_held() or
* rcu_read_lock_trace_held() in all three functions.
*/
BPF_CALL_2(bpf_map_lookup_elem, struct bpf_map *, map, void *, key)
{
WARN_ON_ONCE(!rcu_read_lock_held() && !rcu_read_lock_trace_held() &&
!rcu_read_lock_bh_held());
return (unsigned long) map->ops->map_lookup_elem(map, key);
}
const struct bpf_func_proto bpf_map_lookup_elem_proto = {
.func = bpf_map_lookup_elem,
.gpl_only = false,
.pkt_access = true,
.ret_type = RET_PTR_TO_MAP_VALUE_OR_NULL,
.arg1_type = ARG_CONST_MAP_PTR,
.arg2_type = ARG_PTR_TO_MAP_KEY,
};
BPF_CALL_4(bpf_map_update_elem, struct bpf_map *, map, void *, key,
void *, value, u64, flags)
{
WARN_ON_ONCE(!rcu_read_lock_held() && !rcu_read_lock_trace_held() &&
!rcu_read_lock_bh_held());
return map->ops->map_update_elem(map, key, value, flags);
}
const struct bpf_func_proto bpf_map_update_elem_proto = {
.func = bpf_map_update_elem,
.gpl_only = false,
.pkt_access = true,
.ret_type = RET_INTEGER,
.arg1_type = ARG_CONST_MAP_PTR,
.arg2_type = ARG_PTR_TO_MAP_KEY,
.arg3_type = ARG_PTR_TO_MAP_VALUE,
.arg4_type = ARG_ANYTHING,
};
BPF_CALL_2(bpf_map_delete_elem, struct bpf_map *, map, void *, key)
{
WARN_ON_ONCE(!rcu_read_lock_held() && !rcu_read_lock_trace_held() &&
!rcu_read_lock_bh_held());
return map->ops->map_delete_elem(map, key);
}
const struct bpf_func_proto bpf_map_delete_elem_proto = {
.func = bpf_map_delete_elem,
.gpl_only = false,
.pkt_access = true,
.ret_type = RET_INTEGER,
.arg1_type = ARG_CONST_MAP_PTR,
.arg2_type = ARG_PTR_TO_MAP_KEY,
};
BPF_CALL_3(bpf_map_push_elem, struct bpf_map *, map, void *, value, u64, flags)
{
return map->ops->map_push_elem(map, value, flags);
}
const struct bpf_func_proto bpf_map_push_elem_proto = {
.func = bpf_map_push_elem,
.gpl_only = false,
.pkt_access = true,
.ret_type = RET_INTEGER,
.arg1_type = ARG_CONST_MAP_PTR,
.arg2_type = ARG_PTR_TO_MAP_VALUE,
.arg3_type = ARG_ANYTHING,
};
BPF_CALL_2(bpf_map_pop_elem, struct bpf_map *, map, void *, value)
{
return map->ops->map_pop_elem(map, value);
}
const struct bpf_func_proto bpf_map_pop_elem_proto = {
.func = bpf_map_pop_elem,
.gpl_only = false,
.ret_type = RET_INTEGER,
.arg1_type = ARG_CONST_MAP_PTR,
.arg2_type = ARG_PTR_TO_MAP_VALUE | MEM_UNINIT,
};
BPF_CALL_2(bpf_map_peek_elem, struct bpf_map *, map, void *, value)
{
return map->ops->map_peek_elem(map, value);
}
const struct bpf_func_proto bpf_map_peek_elem_proto = {
.func = bpf_map_peek_elem,
.gpl_only = false,
.ret_type = RET_INTEGER,
.arg1_type = ARG_CONST_MAP_PTR,
.arg2_type = ARG_PTR_TO_MAP_VALUE | MEM_UNINIT,
};
BPF_CALL_3(bpf_map_lookup_percpu_elem, struct bpf_map *, map, void *, key, u32, cpu)
{
WARN_ON_ONCE(!rcu_read_lock_held() && !rcu_read_lock_bh_held());
return (unsigned long) map->ops->map_lookup_percpu_elem(map, key, cpu);
}
const struct bpf_func_proto bpf_map_lookup_percpu_elem_proto = {
.func = bpf_map_lookup_percpu_elem,
.gpl_only = false,
.pkt_access = true,
.ret_type = RET_PTR_TO_MAP_VALUE_OR_NULL,
.arg1_type = ARG_CONST_MAP_PTR,
.arg2_type = ARG_PTR_TO_MAP_KEY,
.arg3_type = ARG_ANYTHING,
};
const struct bpf_func_proto bpf_get_prandom_u32_proto = {
.func = bpf_user_rnd_u32,
.gpl_only = false,
.ret_type = RET_INTEGER,
};
BPF_CALL_0(bpf_get_smp_processor_id)
{
return smp_processor_id();
}
const struct bpf_func_proto bpf_get_smp_processor_id_proto = {
.func = bpf_get_smp_processor_id,
.gpl_only = false,
.ret_type = RET_INTEGER,
.allow_fastcall = true,
};
BPF_CALL_0(bpf_get_numa_node_id)
{
return numa_node_id();
}
const struct bpf_func_proto bpf_get_numa_node_id_proto = {
.func = bpf_get_numa_node_id,
.gpl_only = false,
.ret_type = RET_INTEGER,
};
BPF_CALL_0(bpf_ktime_get_ns)
{
/* NMI safe access to clock monotonic */
return ktime_get_mono_fast_ns();
}
const struct bpf_func_proto bpf_ktime_get_ns_proto = {
.func = bpf_ktime_get_ns,
.gpl_only = false,
.ret_type = RET_INTEGER,
};
BPF_CALL_0(bpf_ktime_get_boot_ns)
{
/* NMI safe access to clock boottime */
return ktime_get_boot_fast_ns();
}
const struct bpf_func_proto bpf_ktime_get_boot_ns_proto = {
.func = bpf_ktime_get_boot_ns,
.gpl_only = false,
.ret_type = RET_INTEGER,
};
BPF_CALL_0(bpf_ktime_get_coarse_ns)
{
return ktime_get_coarse_ns();
}
const struct bpf_func_proto bpf_ktime_get_coarse_ns_proto = {
.func = bpf_ktime_get_coarse_ns,
.gpl_only = false,
.ret_type = RET_INTEGER,
};
BPF_CALL_0(bpf_ktime_get_tai_ns)
{
/* NMI safe access to clock tai */
return ktime_get_tai_fast_ns();
}
const struct bpf_func_proto bpf_ktime_get_tai_ns_proto = {
.func = bpf_ktime_get_tai_ns,
.gpl_only = false,
.ret_type = RET_INTEGER,
};
BPF_CALL_0(bpf_get_current_pid_tgid)
{
struct task_struct *task = current;
if (unlikely(!task))
return -EINVAL;
return (u64) task->tgid << 32 | task->pid;
}
const struct bpf_func_proto bpf_get_current_pid_tgid_proto = {
.func = bpf_get_current_pid_tgid,
.gpl_only = false,
.ret_type = RET_INTEGER,
};
BPF_CALL_0(bpf_get_current_uid_gid)
{
struct task_struct *task = current;
kuid_t uid;
kgid_t gid;
if (unlikely(!task))
return -EINVAL;
current_uid_gid(&uid, &gid);
return (u64) from_kgid(&init_user_ns, gid) << 32 |
from_kuid(&init_user_ns, uid);
}
const struct bpf_func_proto bpf_get_current_uid_gid_proto = {
.func = bpf_get_current_uid_gid,
.gpl_only = false,
.ret_type = RET_INTEGER,
};
BPF_CALL_2(bpf_get_current_comm, char *, buf, u32, size)
{
struct task_struct *task = current;
if (unlikely(!task))
goto err_clear;
/* Verifier guarantees that size > 0 */
strscpy_pad(buf, task->comm, size);
return 0;
err_clear:
memset(buf, 0, size);
return -EINVAL;
}
const struct bpf_func_proto bpf_get_current_comm_proto = {
.func = bpf_get_current_comm,
.gpl_only = false,
.ret_type = RET_INTEGER,
.arg1_type = ARG_PTR_TO_UNINIT_MEM,
.arg2_type = ARG_CONST_SIZE,
};
#if defined(CONFIG_QUEUED_SPINLOCKS) || defined(CONFIG_BPF_ARCH_SPINLOCK)
static inline void __bpf_spin_lock(struct bpf_spin_lock *lock)
{
arch_spinlock_t *l = (void *)lock;
union {
__u32 val;
arch_spinlock_t lock;
} u = { .lock = __ARCH_SPIN_LOCK_UNLOCKED };
compiletime_assert(u.val == 0, "__ARCH_SPIN_LOCK_UNLOCKED not 0");
BUILD_BUG_ON(sizeof(*l) != sizeof(__u32));
BUILD_BUG_ON(sizeof(*lock) != sizeof(__u32));
preempt_disable();
arch_spin_lock(l);
}
static inline void __bpf_spin_unlock(struct bpf_spin_lock *lock)
{
arch_spinlock_t *l = (void *)lock;
arch_spin_unlock(l);
preempt_enable();
}
#else
static inline void __bpf_spin_lock(struct bpf_spin_lock *lock)
{
atomic_t *l = (void *)lock;
BUILD_BUG_ON(sizeof(*l) != sizeof(*lock));
do {
atomic_cond_read_relaxed(l, !VAL);
} while (atomic_xchg(l, 1));
}
static inline void __bpf_spin_unlock(struct bpf_spin_lock *lock)
{
atomic_t *l = (void *)lock;
atomic_set_release(l, 0);
}
#endif
static DEFINE_PER_CPU(unsigned long, irqsave_flags);
static inline void __bpf_spin_lock_irqsave(struct bpf_spin_lock *lock)
{
unsigned long flags;
local_irq_save(flags);
__bpf_spin_lock(lock);
__this_cpu_write(irqsave_flags, flags);
}
NOTRACE_BPF_CALL_1(bpf_spin_lock, struct bpf_spin_lock *, lock)
{
__bpf_spin_lock_irqsave(lock);
return 0;
}
const struct bpf_func_proto bpf_spin_lock_proto = {
.func = bpf_spin_lock,
.gpl_only = false,
.ret_type = RET_VOID,
.arg1_type = ARG_PTR_TO_SPIN_LOCK,
.arg1_btf_id = BPF_PTR_POISON,
};
static inline void __bpf_spin_unlock_irqrestore(struct bpf_spin_lock *lock)
{
unsigned long flags;
flags = __this_cpu_read(irqsave_flags);
__bpf_spin_unlock(lock);
local_irq_restore(flags);
}
NOTRACE_BPF_CALL_1(bpf_spin_unlock, struct bpf_spin_lock *, lock)
{
__bpf_spin_unlock_irqrestore(lock);
return 0;
}
const struct bpf_func_proto bpf_spin_unlock_proto = {
.func = bpf_spin_unlock,
.gpl_only = false,
.ret_type = RET_VOID,
.arg1_type = ARG_PTR_TO_SPIN_LOCK,
.arg1_btf_id = BPF_PTR_POISON,
};
void copy_map_value_locked(struct bpf_map *map, void *dst, void *src,
bool lock_src)
{
struct bpf_spin_lock *lock;
if (lock_src)
lock = src + map->record->spin_lock_off;
else
lock = dst + map->record->spin_lock_off;
preempt_disable();
__bpf_spin_lock_irqsave(lock);
copy_map_value(map, dst, src);
__bpf_spin_unlock_irqrestore(lock);
preempt_enable();
}
BPF_CALL_0(bpf_jiffies64)
{
return get_jiffies_64();
}
const struct bpf_func_proto bpf_jiffies64_proto = {
.func = bpf_jiffies64,
.gpl_only = false,
.ret_type = RET_INTEGER,
};
#ifdef CONFIG_CGROUPS
BPF_CALL_0(bpf_get_current_cgroup_id)
{
struct cgroup *cgrp;
u64 cgrp_id;
rcu_read_lock();
cgrp = task_dfl_cgroup(current);
cgrp_id = cgroup_id(cgrp);
rcu_read_unlock();
return cgrp_id;
}
const struct bpf_func_proto bpf_get_current_cgroup_id_proto = {
.func = bpf_get_current_cgroup_id,
.gpl_only = false,
.ret_type = RET_INTEGER,
};
BPF_CALL_1(bpf_get_current_ancestor_cgroup_id, int, ancestor_level)
{
struct cgroup *cgrp;
struct cgroup *ancestor;
u64 cgrp_id;
rcu_read_lock();
cgrp = task_dfl_cgroup(current);
ancestor = cgroup_ancestor(cgrp, ancestor_level);
cgrp_id = ancestor ? cgroup_id(ancestor) : 0;
rcu_read_unlock();
return cgrp_id;
}
const struct bpf_func_proto bpf_get_current_ancestor_cgroup_id_proto = {
.func = bpf_get_current_ancestor_cgroup_id,
.gpl_only = false,
.ret_type = RET_INTEGER,
.arg1_type = ARG_ANYTHING,
};
#endif /* CONFIG_CGROUPS */
#define BPF_STRTOX_BASE_MASK 0x1F
static int __bpf_strtoull(const char *buf, size_t buf_len, u64 flags,
unsigned long long *res, bool *is_negative)
{
unsigned int base = flags & BPF_STRTOX_BASE_MASK;
const char *cur_buf = buf;
size_t cur_len = buf_len;
unsigned int consumed;
size_t val_len;
char str[64];
if (!buf || !buf_len || !res || !is_negative)
return -EINVAL;
if (base != 0 && base != 8 && base != 10 && base != 16)
return -EINVAL;
if (flags & ~BPF_STRTOX_BASE_MASK)
return -EINVAL;
while (cur_buf < buf + buf_len && isspace(*cur_buf))
++cur_buf;
*is_negative = (cur_buf < buf + buf_len && *cur_buf == '-');
if (*is_negative)
++cur_buf;
consumed = cur_buf - buf;
cur_len -= consumed;
if (!cur_len)
return -EINVAL;
cur_len = min(cur_len, sizeof(str) - 1);
memcpy(str, cur_buf, cur_len);
str[cur_len] = '\0';
cur_buf = str;
cur_buf = _parse_integer_fixup_radix(cur_buf, &base);
val_len = _parse_integer(cur_buf, base, res);
if (val_len & KSTRTOX_OVERFLOW)
return -ERANGE;
if (val_len == 0)
return -EINVAL;
cur_buf += val_len;
consumed += cur_buf - str;
return consumed;
}
static int __bpf_strtoll(const char *buf, size_t buf_len, u64 flags,
long long *res)
{
unsigned long long _res;
bool is_negative;
int err;
err = __bpf_strtoull(buf, buf_len, flags, &_res, &is_negative);
if (err < 0)
return err;
if (is_negative) {
if ((long long)-_res > 0)
return -ERANGE;
*res = -_res;
} else {
if ((long long)_res < 0)
return -ERANGE;
*res = _res;
}
return err;
}
BPF_CALL_4(bpf_strtol, const char *, buf, size_t, buf_len, u64, flags,
s64 *, res)
{
long long _res;
int err;
*res = 0;
err = __bpf_strtoll(buf, buf_len, flags, &_res);
if (err < 0)
return err;
*res = _res;
return err;
}
const struct bpf_func_proto bpf_strtol_proto = {
.func = bpf_strtol,
.gpl_only = false,
.ret_type = RET_INTEGER,
.arg1_type = ARG_PTR_TO_MEM | MEM_RDONLY,
.arg2_type = ARG_CONST_SIZE,
.arg3_type = ARG_ANYTHING,
.arg4_type = ARG_PTR_TO_FIXED_SIZE_MEM | MEM_UNINIT | MEM_ALIGNED,
.arg4_size = sizeof(s64),
};
BPF_CALL_4(bpf_strtoul, const char *, buf, size_t, buf_len, u64, flags,
u64 *, res)
{
unsigned long long _res;
bool is_negative;
int err;
*res = 0;
err = __bpf_strtoull(buf, buf_len, flags, &_res, &is_negative);
if (err < 0)
return err;
if (is_negative)
return -EINVAL;
*res = _res;
return err;
}
const struct bpf_func_proto bpf_strtoul_proto = {
.func = bpf_strtoul,
.gpl_only = false,
.ret_type = RET_INTEGER,
.arg1_type = ARG_PTR_TO_MEM | MEM_RDONLY,
.arg2_type = ARG_CONST_SIZE,
.arg3_type = ARG_ANYTHING,
.arg4_type = ARG_PTR_TO_FIXED_SIZE_MEM | MEM_UNINIT | MEM_ALIGNED,
.arg4_size = sizeof(u64),
};
BPF_CALL_3(bpf_strncmp, const char *, s1, u32, s1_sz, const char *, s2)
{
return strncmp(s1, s2, s1_sz);
}
static const struct bpf_func_proto bpf_strncmp_proto = {
.func = bpf_strncmp,
.gpl_only = false,
.ret_type = RET_INTEGER,
.arg1_type = ARG_PTR_TO_MEM | MEM_RDONLY,
.arg2_type = ARG_CONST_SIZE,
.arg3_type = ARG_PTR_TO_CONST_STR,
};
BPF_CALL_4(bpf_get_ns_current_pid_tgid, u64, dev, u64, ino,
struct bpf_pidns_info *, nsdata, u32, size)
{
struct task_struct *task = current;
struct pid_namespace *pidns;
int err = -EINVAL;
if (unlikely(size != sizeof(struct bpf_pidns_info)))
goto clear;
if (unlikely((u64)(dev_t)dev != dev))
goto clear;
if (unlikely(!task))
goto clear;
pidns = task_active_pid_ns(task);
if (unlikely(!pidns)) {
err = -ENOENT;
goto clear;
}
if (!ns_match(&pidns->ns, (dev_t)dev, ino))
goto clear;
nsdata->pid = task_pid_nr_ns(task, pidns);
nsdata->tgid = task_tgid_nr_ns(task, pidns);
return 0;
clear:
memset((void *)nsdata, 0, (size_t) size);
return err;
}
const struct bpf_func_proto bpf_get_ns_current_pid_tgid_proto = {
.func = bpf_get_ns_current_pid_tgid,
.gpl_only = false,
.ret_type = RET_INTEGER,
.arg1_type = ARG_ANYTHING,
.arg2_type = ARG_ANYTHING,
.arg3_type = ARG_PTR_TO_UNINIT_MEM,
.arg4_type = ARG_CONST_SIZE,
};
static const struct bpf_func_proto bpf_get_raw_smp_processor_id_proto = {
.func = bpf_get_raw_cpu_id,
.gpl_only = false,
.ret_type = RET_INTEGER,
};
BPF_CALL_5(bpf_event_output_data, void *, ctx, struct bpf_map *, map,
u64, flags, void *, data, u64, size)
{
if (unlikely(flags & ~(BPF_F_INDEX_MASK)))
return -EINVAL;
return bpf_event_output(map, flags, data, size, NULL, 0, NULL);
}
const struct bpf_func_proto bpf_event_output_data_proto = {
.func = bpf_event_output_data,
.gpl_only = true,
.ret_type = RET_INTEGER,
.arg1_type = ARG_PTR_TO_CTX,
.arg2_type = ARG_CONST_MAP_PTR,
.arg3_type = ARG_ANYTHING,
.arg4_type = ARG_PTR_TO_MEM | MEM_RDONLY,
.arg5_type = ARG_CONST_SIZE_OR_ZERO,
};
BPF_CALL_3(bpf_copy_from_user, void *, dst, u32, size,
const void __user *, user_ptr)
{
int ret = copy_from_user(dst, user_ptr, size);
if (unlikely(ret)) {
memset(dst, 0, size);
ret = -EFAULT;
}
return ret;
}
const struct bpf_func_proto bpf_copy_from_user_proto = {
.func = bpf_copy_from_user,
.gpl_only = false,
.might_sleep = true,
.ret_type = RET_INTEGER,
.arg1_type = ARG_PTR_TO_UNINIT_MEM,
.arg2_type = ARG_CONST_SIZE_OR_ZERO,
.arg3_type = ARG_ANYTHING,
};
BPF_CALL_5(bpf_copy_from_user_task, void *, dst, u32, size,
const void __user *, user_ptr, struct task_struct *, tsk, u64, flags)
{
int ret;
/* flags is not used yet */
if (unlikely(flags))
return -EINVAL;
if (unlikely(!size))
return 0;
ret = access_process_vm(tsk, (unsigned long)user_ptr, dst, size, 0);
if (ret == size)
return 0;
memset(dst, 0, size);
/* Return -EFAULT for partial read */
return ret < 0 ? ret : -EFAULT;
}
const struct bpf_func_proto bpf_copy_from_user_task_proto = {
.func = bpf_copy_from_user_task,
.gpl_only = true,
.might_sleep = true,
.ret_type = RET_INTEGER,
.arg1_type = ARG_PTR_TO_UNINIT_MEM,
.arg2_type = ARG_CONST_SIZE_OR_ZERO,
.arg3_type = ARG_ANYTHING,
.arg4_type = ARG_PTR_TO_BTF_ID,
.arg4_btf_id = &btf_tracing_ids[BTF_TRACING_TYPE_TASK],
.arg5_type = ARG_ANYTHING
};
BPF_CALL_2(bpf_per_cpu_ptr, const void *, ptr, u32, cpu)
{
if (cpu >= nr_cpu_ids)
return (unsigned long)NULL;
return (unsigned long)per_cpu_ptr((const void __percpu *)(const uintptr_t)ptr, cpu);
}
const struct bpf_func_proto bpf_per_cpu_ptr_proto = {
.func = bpf_per_cpu_ptr,
.gpl_only = false,
.ret_type = RET_PTR_TO_MEM_OR_BTF_ID | PTR_MAYBE_NULL | MEM_RDONLY,
.arg1_type = ARG_PTR_TO_PERCPU_BTF_ID,
.arg2_type = ARG_ANYTHING,
};
BPF_CALL_1(bpf_this_cpu_ptr, const void *, percpu_ptr)
{
return (unsigned long)this_cpu_ptr((const void __percpu *)(const uintptr_t)percpu_ptr);
}
const struct bpf_func_proto bpf_this_cpu_ptr_proto = {
.func = bpf_this_cpu_ptr,
.gpl_only = false,
.ret_type = RET_PTR_TO_MEM_OR_BTF_ID | MEM_RDONLY,
.arg1_type = ARG_PTR_TO_PERCPU_BTF_ID,
};
static int bpf_trace_copy_string(char *buf, void *unsafe_ptr, char fmt_ptype,
size_t bufsz)
{
void __user *user_ptr = (__force void __user *)unsafe_ptr;
buf[0] = 0;
switch (fmt_ptype) {
case 's':
#ifdef CONFIG_ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE
if ((unsigned long)unsafe_ptr < TASK_SIZE)
return strncpy_from_user_nofault(buf, user_ptr, bufsz);
fallthrough;
#endif
case 'k':
return strncpy_from_kernel_nofault(buf, unsafe_ptr, bufsz);
case 'u':
return strncpy_from_user_nofault(buf, user_ptr, bufsz);
}
return -EINVAL;
}
/* Per-cpu temp buffers used by printf-like helpers to store the bprintf binary
* arguments representation.
*/
#define MAX_BPRINTF_BIN_ARGS 512
/* Support executing three nested bprintf helper calls on a given CPU */
#define MAX_BPRINTF_NEST_LEVEL 3
struct bpf_bprintf_buffers {
char bin_args[MAX_BPRINTF_BIN_ARGS];
char buf[MAX_BPRINTF_BUF];
};
static DEFINE_PER_CPU(struct bpf_bprintf_buffers[MAX_BPRINTF_NEST_LEVEL], bpf_bprintf_bufs);
static DEFINE_PER_CPU(int, bpf_bprintf_nest_level);
static int try_get_buffers(struct bpf_bprintf_buffers **bufs)
{
int nest_level;
preempt_disable();
nest_level = this_cpu_inc_return(bpf_bprintf_nest_level);
if (WARN_ON_ONCE(nest_level > MAX_BPRINTF_NEST_LEVEL)) {
this_cpu_dec(bpf_bprintf_nest_level);
preempt_enable();
return -EBUSY;
}
*bufs = this_cpu_ptr(&bpf_bprintf_bufs[nest_level - 1]);
return 0;
}
void bpf_bprintf_cleanup(struct bpf_bprintf_data *data)
{
if (!data->bin_args && !data->buf)
return;
if (WARN_ON_ONCE(this_cpu_read(bpf_bprintf_nest_level) == 0))
return;
this_cpu_dec(bpf_bprintf_nest_level);
preempt_enable();
}
/*
* bpf_bprintf_prepare - Generic pass on format strings for bprintf-like helpers
*
* Returns a negative value if fmt is an invalid format string or 0 otherwise.
*
* This can be used in two ways:
* - Format string verification only: when data->get_bin_args is false
* - Arguments preparation: in addition to the above verification, it writes in
* data->bin_args a binary representation of arguments usable by bstr_printf
* where pointers from BPF have been sanitized.
*
* In argument preparation mode, if 0 is returned, safe temporary buffers are
* allocated and bpf_bprintf_cleanup should be called to free them after use.
*/
int bpf_bprintf_prepare(char *fmt, u32 fmt_size, const u64 *raw_args,
u32 num_args, struct bpf_bprintf_data *data)
{
bool get_buffers = (data->get_bin_args && num_args) || data->get_buf;
char *unsafe_ptr = NULL, *tmp_buf = NULL, *tmp_buf_end, *fmt_end;
struct bpf_bprintf_buffers *buffers = NULL;
size_t sizeof_cur_arg, sizeof_cur_ip;
int err, i, num_spec = 0;
u64 cur_arg;
char fmt_ptype, cur_ip[16], ip_spec[] = "%pXX";
fmt_end = strnchr(fmt, fmt_size, 0);
if (!fmt_end)
return -EINVAL;
fmt_size = fmt_end - fmt;
if (get_buffers && try_get_buffers(&buffers))
return -EBUSY;
if (data->get_bin_args) {
if (num_args)
tmp_buf = buffers->bin_args;
tmp_buf_end = tmp_buf + MAX_BPRINTF_BIN_ARGS;
data->bin_args = (u32 *)tmp_buf;
}
if (data->get_buf)
data->buf = buffers->buf;
for (i = 0; i < fmt_size; i++) {
if ((!isprint(fmt[i]) && !isspace(fmt[i])) || !isascii(fmt[i])) {
err = -EINVAL;
goto out;
}
if (fmt[i] != '%')
continue;
if (fmt[i + 1] == '%') {
i++;
continue;
}
if (num_spec >= num_args) {
err = -EINVAL;
goto out;
}
/* The string is zero-terminated so if fmt[i] != 0, we can
* always access fmt[i + 1], in the worst case it will be a 0
*/
i++;
/* skip optional "[0 +-][num]" width formatting field */
while (fmt[i] == '0' || fmt[i] == '+' || fmt[i] == '-' ||
fmt[i] == ' ')
i++;
if (fmt[i] >= '1' && fmt[i] <= '9') {
i++;
while (fmt[i] >= '0' && fmt[i] <= '9')
i++;
}
if (fmt[i] == 'p') {
sizeof_cur_arg = sizeof(long);
if ((fmt[i + 1] == 'k' || fmt[i + 1] == 'u') &&
fmt[i + 2] == 's') {
fmt_ptype = fmt[i + 1];
i += 2;
goto fmt_str;
}
if (fmt[i + 1] == 0 || isspace(fmt[i + 1]) ||
ispunct(fmt[i + 1]) || fmt[i + 1] == 'K' ||
fmt[i + 1] == 'x' || fmt[i + 1] == 's' ||
fmt[i + 1] == 'S') {
/* just kernel pointers */
if (tmp_buf)
cur_arg = raw_args[num_spec];
i++;
goto nocopy_fmt;
}
if (fmt[i + 1] == 'B') {
if (tmp_buf) {
err = snprintf(tmp_buf,
(tmp_buf_end - tmp_buf),
"%pB",
(void *)(long)raw_args[num_spec]);
tmp_buf += (err + 1);
}
i++;
num_spec++;
continue;
}
/* only support "%pI4", "%pi4", "%pI6" and "%pi6". */
if ((fmt[i + 1] != 'i' && fmt[i + 1] != 'I') ||
(fmt[i + 2] != '4' && fmt[i + 2] != '6')) {
err = -EINVAL;
goto out;
}
i += 2;
if (!tmp_buf)
goto nocopy_fmt;
sizeof_cur_ip = (fmt[i] == '4') ? 4 : 16;
if (tmp_buf_end - tmp_buf < sizeof_cur_ip) {
err = -ENOSPC;
goto out;
}
unsafe_ptr = (char *)(long)raw_args[num_spec];
err = copy_from_kernel_nofault(cur_ip, unsafe_ptr,
sizeof_cur_ip);
if (err < 0)
memset(cur_ip, 0, sizeof_cur_ip);
/* hack: bstr_printf expects IP addresses to be
* pre-formatted as strings, ironically, the easiest way
* to do that is to call snprintf.
*/
ip_spec[2] = fmt[i - 1];
ip_spec[3] = fmt[i];
err = snprintf(tmp_buf, tmp_buf_end - tmp_buf,
ip_spec, &cur_ip);
tmp_buf += err + 1;
num_spec++;
continue;
} else if (fmt[i] == 's') {
fmt_ptype = fmt[i];
fmt_str:
if (fmt[i + 1] != 0 &&
!isspace(fmt[i + 1]) &&
!ispunct(fmt[i + 1])) {
err = -EINVAL;
goto out;
}
if (!tmp_buf)
goto nocopy_fmt;
if (tmp_buf_end == tmp_buf) {
err = -ENOSPC;
goto out;
}
unsafe_ptr = (char *)(long)raw_args[num_spec];
err = bpf_trace_copy_string(tmp_buf, unsafe_ptr,
fmt_ptype,
tmp_buf_end - tmp_buf);
if (err < 0) {
tmp_buf[0] = '\0';
err = 1;
}
tmp_buf += err;
num_spec++;
continue;
} else if (fmt[i] == 'c') {
if (!tmp_buf)
goto nocopy_fmt;
if (tmp_buf_end == tmp_buf) {
err = -ENOSPC;
goto out;
}
*tmp_buf = raw_args[num_spec];
tmp_buf++;
num_spec++;
continue;
}
sizeof_cur_arg = sizeof(int);
if (fmt[i] == 'l') {
sizeof_cur_arg = sizeof(long);
i++;
}
if (fmt[i] == 'l') {
sizeof_cur_arg = sizeof(long long);
i++;
}
if (fmt[i] != 'i' && fmt[i] != 'd' && fmt[i] != 'u' &&
fmt[i] != 'x' && fmt[i] != 'X') {
err = -EINVAL;
goto out;
}
if (tmp_buf)
cur_arg = raw_args[num_spec];
nocopy_fmt:
if (tmp_buf) {
tmp_buf = PTR_ALIGN(tmp_buf, sizeof(u32));
if (tmp_buf_end - tmp_buf < sizeof_cur_arg) {
err = -ENOSPC;
goto out;
}
if (sizeof_cur_arg == 8) {
*(u32 *)tmp_buf = *(u32 *)&cur_arg;
*(u32 *)(tmp_buf + 4) = *((u32 *)&cur_arg + 1);
} else {
*(u32 *)tmp_buf = (u32)(long)cur_arg;
}
tmp_buf += sizeof_cur_arg;
}
num_spec++;
}
err = 0;
out:
if (err)
bpf_bprintf_cleanup(data);
return err;
}
BPF_CALL_5(bpf_snprintf, char *, str, u32, str_size, char *, fmt,
const void *, args, u32, data_len)
{
struct bpf_bprintf_data data = {
.get_bin_args = true,
};
int err, num_args;
if (data_len % 8 || data_len > MAX_BPRINTF_VARARGS * 8 ||
(data_len && !args))
return -EINVAL;
num_args = data_len / 8;
/* ARG_PTR_TO_CONST_STR guarantees that fmt is zero-terminated so we
* can safely give an unbounded size.
*/
err = bpf_bprintf_prepare(fmt, UINT_MAX, args, num_args, &data);
if (err < 0)
return err;
err = bstr_printf(str, str_size, fmt, data.bin_args);
bpf_bprintf_cleanup(&data);
return err + 1;
}
const struct bpf_func_proto bpf_snprintf_proto = {
.func = bpf_snprintf,
.gpl_only = true,
.ret_type = RET_INTEGER,
.arg1_type = ARG_PTR_TO_MEM_OR_NULL,
.arg2_type = ARG_CONST_SIZE_OR_ZERO,
.arg3_type = ARG_PTR_TO_CONST_STR,
.arg4_type = ARG_PTR_TO_MEM | PTR_MAYBE_NULL | MEM_RDONLY,
.arg5_type = ARG_CONST_SIZE_OR_ZERO,
};
struct bpf_async_cb {
struct bpf_map *map;
struct bpf_prog *prog;
void __rcu *callback_fn;
void *value;
union {
struct rcu_head rcu;
struct work_struct delete_work;
};
u64 flags;
};
/* BPF map elements can contain 'struct bpf_timer'.
* Such map owns all of its BPF timers.
* 'struct bpf_timer' is allocated as part of map element allocation
* and it's zero initialized.
* That space is used to keep 'struct bpf_async_kern'.
* bpf_timer_init() allocates 'struct bpf_hrtimer', inits hrtimer, and
* remembers 'struct bpf_map *' pointer it's part of.
* bpf_timer_set_callback() increments prog refcnt and assign bpf callback_fn.
* bpf_timer_start() arms the timer.
* If user space reference to a map goes to zero at this point
* ops->map_release_uref callback is responsible for cancelling the timers,
* freeing their memory, and decrementing prog's refcnts.
* bpf_timer_cancel() cancels the timer and decrements prog's refcnt.
* Inner maps can contain bpf timers as well. ops->map_release_uref is
* freeing the timers when inner map is replaced or deleted by user space.
*/
struct bpf_hrtimer {
struct bpf_async_cb cb;
struct hrtimer timer;
atomic_t cancelling;
};
struct bpf_work {
struct bpf_async_cb cb;
struct work_struct work;
struct work_struct delete_work;
};
/* the actual struct hidden inside uapi struct bpf_timer and bpf_wq */
struct bpf_async_kern {
union {
struct bpf_async_cb *cb;
struct bpf_hrtimer *timer;
struct bpf_work *work;
};
/* bpf_spin_lock is used here instead of spinlock_t to make
* sure that it always fits into space reserved by struct bpf_timer
* regardless of LOCKDEP and spinlock debug flags.
*/
struct bpf_spin_lock lock;
} __attribute__((aligned(8)));
enum bpf_async_type {
BPF_ASYNC_TYPE_TIMER = 0,
BPF_ASYNC_TYPE_WQ,
};
static DEFINE_PER_CPU(struct bpf_hrtimer *, hrtimer_running);
static enum hrtimer_restart bpf_timer_cb(struct hrtimer *hrtimer)
{
struct bpf_hrtimer *t = container_of(hrtimer, struct bpf_hrtimer, timer);
struct bpf_map *map = t->cb.map;
void *value = t->cb.value;
bpf_callback_t callback_fn;
void *key;
u32 idx;
BTF_TYPE_EMIT(struct bpf_timer);
callback_fn = rcu_dereference_check(t->cb.callback_fn, rcu_read_lock_bh_held());
if (!callback_fn)
goto out;
/* bpf_timer_cb() runs in hrtimer_run_softirq. It doesn't migrate and
* cannot be preempted by another bpf_timer_cb() on the same cpu.
* Remember the timer this callback is servicing to prevent
* deadlock if callback_fn() calls bpf_timer_cancel() or
* bpf_map_delete_elem() on the same timer.
*/
this_cpu_write(hrtimer_running, t);
if (map->map_type == BPF_MAP_TYPE_ARRAY) {
struct bpf_array *array = container_of(map, struct bpf_array, map);
/* compute the key */
idx = ((char *)value - array->value) / array->elem_size;
key = &idx;
} else { /* hash or lru */
key = value - round_up(map->key_size, 8);
}
callback_fn((u64)(long)map, (u64)(long)key, (u64)(long)value, 0, 0);
/* The verifier checked that return value is zero. */
this_cpu_write(hrtimer_running, NULL);
out:
return HRTIMER_NORESTART;
}
static void bpf_wq_work(struct work_struct *work)
{
struct bpf_work *w = container_of(work, struct bpf_work, work);
struct bpf_async_cb *cb = &w->cb;
struct bpf_map *map = cb->map;
bpf_callback_t callback_fn;
void *value = cb->value;
void *key;
u32 idx;
BTF_TYPE_EMIT(struct bpf_wq);
callback_fn = READ_ONCE(cb->callback_fn);
if (!callback_fn)
return;
if (map->map_type == BPF_MAP_TYPE_ARRAY) {
struct bpf_array *array = container_of(map, struct bpf_array, map);
/* compute the key */
idx = ((char *)value - array->value) / array->elem_size;
key = &idx;
} else { /* hash or lru */
key = value - round_up(map->key_size, 8);
}
rcu_read_lock_trace();
migrate_disable();
callback_fn((u64)(long)map, (u64)(long)key, (u64)(long)value, 0, 0);
migrate_enable();
rcu_read_unlock_trace();
}
static void bpf_wq_delete_work(struct work_struct *work)
{
struct bpf_work *w = container_of(work, struct bpf_work, delete_work);
cancel_work_sync(&w->work);
kfree_rcu(w, cb.rcu);
}
static void bpf_timer_delete_work(struct work_struct *work)
{
struct bpf_hrtimer *t = container_of(work, struct bpf_hrtimer, cb.delete_work);
/* Cancel the timer and wait for callback to complete if it was running.
* If hrtimer_cancel() can be safely called it's safe to call
* kfree_rcu(t) right after for both preallocated and non-preallocated
* maps. The async->cb = NULL was already done and no code path can see
* address 't' anymore. Timer if armed for existing bpf_hrtimer before
* bpf_timer_cancel_and_free will have been cancelled.
*/
hrtimer_cancel(&t->timer);
kfree_rcu(t, cb.rcu);
}
static int __bpf_async_init(struct bpf_async_kern *async, struct bpf_map *map, u64 flags,
enum bpf_async_type type)
{
struct bpf_async_cb *cb;
struct bpf_hrtimer *t;
struct bpf_work *w;
clockid_t clockid;
size_t size;
int ret = 0;
if (in_nmi())
return -EOPNOTSUPP;
switch (type) {
case BPF_ASYNC_TYPE_TIMER:
size = sizeof(struct bpf_hrtimer);
break;
case BPF_ASYNC_TYPE_WQ:
size = sizeof(struct bpf_work);
break;
default:
return -EINVAL;
}
__bpf_spin_lock_irqsave(&async->lock);
t = async->timer;
if (t) {
ret = -EBUSY;
goto out;
}
/* allocate hrtimer via map_kmalloc to use memcg accounting */
cb = bpf_map_kmalloc_node(map, size, GFP_ATOMIC, map->numa_node);
if (!cb) {
ret = -ENOMEM;
goto out;
}
switch (type) {
case BPF_ASYNC_TYPE_TIMER:
clockid = flags & (MAX_CLOCKS - 1);
t = (struct bpf_hrtimer *)cb;
atomic_set(&t->cancelling, 0);
INIT_WORK(&t->cb.delete_work, bpf_timer_delete_work);
hrtimer_init(&t->timer, clockid, HRTIMER_MODE_REL_SOFT);
t->timer.function = bpf_timer_cb;
cb->value = (void *)async - map->record->timer_off;
break;
case BPF_ASYNC_TYPE_WQ:
w = (struct bpf_work *)cb;
INIT_WORK(&w->work, bpf_wq_work);
INIT_WORK(&w->delete_work, bpf_wq_delete_work);
cb->value = (void *)async - map->record->wq_off;
break;
}
cb->map = map;
cb->prog = NULL;
cb->flags = flags;
rcu_assign_pointer(cb->callback_fn, NULL);
WRITE_ONCE(async->cb, cb);
/* Guarantee the order between async->cb and map->usercnt. So
* when there are concurrent uref release and bpf timer init, either
* bpf_timer_cancel_and_free() called by uref release reads a no-NULL
* timer or atomic64_read() below returns a zero usercnt.
*/
smp_mb();
if (!atomic64_read(&map->usercnt)) {
/* maps with timers must be either held by user space
* or pinned in bpffs.
*/
WRITE_ONCE(async->cb, NULL);
kfree(cb);
ret = -EPERM;
}
out:
__bpf_spin_unlock_irqrestore(&async->lock);
return ret;
}
BPF_CALL_3(bpf_timer_init, struct bpf_async_kern *, timer, struct bpf_map *, map,
u64, flags)
{
clock_t clockid = flags & (MAX_CLOCKS - 1);
BUILD_BUG_ON(MAX_CLOCKS != 16);
BUILD_BUG_ON(sizeof(struct bpf_async_kern) > sizeof(struct bpf_timer));
BUILD_BUG_ON(__alignof__(struct bpf_async_kern) != __alignof__(struct bpf_timer));
if (flags >= MAX_CLOCKS ||
/* similar to timerfd except _ALARM variants are not supported */
(clockid != CLOCK_MONOTONIC &&
clockid != CLOCK_REALTIME &&
clockid != CLOCK_BOOTTIME))
return -EINVAL;
return __bpf_async_init(timer, map, flags, BPF_ASYNC_TYPE_TIMER);
}
static const struct bpf_func_proto bpf_timer_init_proto = {
.func = bpf_timer_init,
.gpl_only = true,
.ret_type = RET_INTEGER,
.arg1_type = ARG_PTR_TO_TIMER,
.arg2_type = ARG_CONST_MAP_PTR,
.arg3_type = ARG_ANYTHING,
};
static int __bpf_async_set_callback(struct bpf_async_kern *async, void *callback_fn,
struct bpf_prog_aux *aux, unsigned int flags,
enum bpf_async_type type)
{
struct bpf_prog *prev, *prog = aux->prog;
struct bpf_async_cb *cb;
int ret = 0;
if (in_nmi())
return -EOPNOTSUPP;
__bpf_spin_lock_irqsave(&async->lock);
cb = async->cb;
if (!cb) {
ret = -EINVAL;
goto out;
}
if (!atomic64_read(&cb->map->usercnt)) {
/* maps with timers must be either held by user space
* or pinned in bpffs. Otherwise timer might still be
* running even when bpf prog is detached and user space
* is gone, since map_release_uref won't ever be called.
*/
ret = -EPERM;
goto out;
}
prev = cb->prog;
if (prev != prog) {
/* Bump prog refcnt once. Every bpf_timer_set_callback()
* can pick different callback_fn-s within the same prog.
*/
prog = bpf_prog_inc_not_zero(prog);
if (IS_ERR(prog)) {
ret = PTR_ERR(prog);
goto out;
}
if (prev)
/* Drop prev prog refcnt when swapping with new prog */
bpf_prog_put(prev);
cb->prog = prog;
}
rcu_assign_pointer(cb->callback_fn, callback_fn);
out:
__bpf_spin_unlock_irqrestore(&async->lock);
return ret;
}
BPF_CALL_3(bpf_timer_set_callback, struct bpf_async_kern *, timer, void *, callback_fn,
struct bpf_prog_aux *, aux)
{
return __bpf_async_set_callback(timer, callback_fn, aux, 0, BPF_ASYNC_TYPE_TIMER);
}
static const struct bpf_func_proto bpf_timer_set_callback_proto = {
.func = bpf_timer_set_callback,
.gpl_only = true,
.ret_type = RET_INTEGER,
.arg1_type = ARG_PTR_TO_TIMER,
.arg2_type = ARG_PTR_TO_FUNC,
};
BPF_CALL_3(bpf_timer_start, struct bpf_async_kern *, timer, u64, nsecs, u64, flags)
{
struct bpf_hrtimer *t;
int ret = 0;
enum hrtimer_mode mode;
if (in_nmi())
return -EOPNOTSUPP;
if (flags & ~(BPF_F_TIMER_ABS | BPF_F_TIMER_CPU_PIN))
return -EINVAL;
__bpf_spin_lock_irqsave(&timer->lock);
t = timer->timer;
if (!t || !t->cb.prog) {
ret = -EINVAL;
goto out;
}
if (flags & BPF_F_TIMER_ABS)
mode = HRTIMER_MODE_ABS_SOFT;
else
mode = HRTIMER_MODE_REL_SOFT;
if (flags & BPF_F_TIMER_CPU_PIN)
mode |= HRTIMER_MODE_PINNED;
hrtimer_start(&t->timer, ns_to_ktime(nsecs), mode);
out:
__bpf_spin_unlock_irqrestore(&timer->lock);
return ret;
}
static const struct bpf_func_proto bpf_timer_start_proto = {
.func = bpf_timer_start,
.gpl_only = true,
.ret_type = RET_INTEGER,
.arg1_type = ARG_PTR_TO_TIMER,
.arg2_type = ARG_ANYTHING,
.arg3_type = ARG_ANYTHING,
};
static void drop_prog_refcnt(struct bpf_async_cb *async)
{
struct bpf_prog *prog = async->prog;
if (prog) {
bpf_prog_put(prog);
async->prog = NULL;
rcu_assign_pointer(async->callback_fn, NULL);
}
}
BPF_CALL_1(bpf_timer_cancel, struct bpf_async_kern *, timer)
{
struct bpf_hrtimer *t, *cur_t;
bool inc = false;
int ret = 0;
if (in_nmi())
return -EOPNOTSUPP;
rcu_read_lock();
__bpf_spin_lock_irqsave(&timer->lock);
t = timer->timer;
if (!t) {
ret = -EINVAL;
goto out;
}
cur_t = this_cpu_read(hrtimer_running);
if (cur_t == t) {
/* If bpf callback_fn is trying to bpf_timer_cancel()
* its own timer the hrtimer_cancel() will deadlock
* since it waits for callback_fn to finish.
*/
ret = -EDEADLK;
goto out;
}
/* Only account in-flight cancellations when invoked from a timer
* callback, since we want to avoid waiting only if other _callbacks_
* are waiting on us, to avoid introducing lockups. Non-callback paths
* are ok, since nobody would synchronously wait for their completion.
*/
if (!cur_t)
goto drop;
atomic_inc(&t->cancelling);
/* Need full barrier after relaxed atomic_inc */
smp_mb__after_atomic();
inc = true;
if (atomic_read(&cur_t->cancelling)) {
/* We're cancelling timer t, while some other timer callback is
* attempting to cancel us. In such a case, it might be possible
* that timer t belongs to the other callback, or some other
* callback waiting upon it (creating transitive dependencies
* upon us), and we will enter a deadlock if we continue
* cancelling and waiting for it synchronously, since it might
* do the same. Bail!
*/
ret = -EDEADLK;
goto out;
}
drop:
drop_prog_refcnt(&t->cb);
out:
__bpf_spin_unlock_irqrestore(&timer->lock);
/* Cancel the timer and wait for associated callback to finish
* if it was running.
*/
ret = ret ?: hrtimer_cancel(&t->timer);
if (inc)
atomic_dec(&t->cancelling);
rcu_read_unlock();
return ret;
}
static const struct bpf_func_proto bpf_timer_cancel_proto = {
.func = bpf_timer_cancel,
.gpl_only = true,
.ret_type = RET_INTEGER,
.arg1_type = ARG_PTR_TO_TIMER,
};
static struct bpf_async_cb *__bpf_async_cancel_and_free(struct bpf_async_kern *async)
{
struct bpf_async_cb *cb;
/* Performance optimization: read async->cb without lock first. */
if (!READ_ONCE(async->cb))
return NULL;
__bpf_spin_lock_irqsave(&async->lock);
/* re-read it under lock */
cb = async->cb;
if (!cb)
goto out;
drop_prog_refcnt(cb);
/* The subsequent bpf_timer_start/cancel() helpers won't be able to use
* this timer, since it won't be initialized.
*/
WRITE_ONCE(async->cb, NULL);
out:
__bpf_spin_unlock_irqrestore(&async->lock);
return cb;
}
/* This function is called by map_delete/update_elem for individual element and
* by ops->map_release_uref when the user space reference to a map reaches zero.
*/
void bpf_timer_cancel_and_free(void *val)
{
struct bpf_hrtimer *t;
t = (struct bpf_hrtimer *)__bpf_async_cancel_and_free(val);
if (!t)
return;
/* We check that bpf_map_delete/update_elem() was called from timer
* callback_fn. In such case we don't call hrtimer_cancel() (since it
* will deadlock) and don't call hrtimer_try_to_cancel() (since it will
* just return -1). Though callback_fn is still running on this cpu it's
* safe to do kfree(t) because bpf_timer_cb() read everything it needed
* from 't'. The bpf subprog callback_fn won't be able to access 't',
* since async->cb = NULL was already done. The timer will be
* effectively cancelled because bpf_timer_cb() will return
* HRTIMER_NORESTART.
*
* However, it is possible the timer callback_fn calling us armed the
* timer _before_ calling us, such that failing to cancel it here will
* cause it to possibly use struct hrtimer after freeing bpf_hrtimer.
* Therefore, we _need_ to cancel any outstanding timers before we do
* kfree_rcu, even though no more timers can be armed.
*
* Moreover, we need to schedule work even if timer does not belong to
* the calling callback_fn, as on two different CPUs, we can end up in a
* situation where both sides run in parallel, try to cancel one
* another, and we end up waiting on both sides in hrtimer_cancel
* without making forward progress, since timer1 depends on time2
* callback to finish, and vice versa.
*
* CPU 1 (timer1_cb) CPU 2 (timer2_cb)
* bpf_timer_cancel_and_free(timer2) bpf_timer_cancel_and_free(timer1)
*
* To avoid these issues, punt to workqueue context when we are in a
* timer callback.
*/
if (this_cpu_read(hrtimer_running))
queue_work(system_unbound_wq, &t->cb.delete_work);
else
bpf_timer_delete_work(&t->cb.delete_work);
}
/* This function is called by map_delete/update_elem for individual element and
* by ops->map_release_uref when the user space reference to a map reaches zero.
*/
void bpf_wq_cancel_and_free(void *val)
{
struct bpf_work *work;
BTF_TYPE_EMIT(struct bpf_wq);
work = (struct bpf_work *)__bpf_async_cancel_and_free(val);
if (!work)
return;
/* Trigger cancel of the sleepable work, but *do not* wait for
* it to finish if it was running as we might not be in a
* sleepable context.
* kfree will be called once the work has finished.
*/
schedule_work(&work->delete_work);
}
BPF_CALL_2(bpf_kptr_xchg, void *, dst, void *, ptr)
{
unsigned long *kptr = dst;
/* This helper may be inlined by verifier. */
return xchg(kptr, (unsigned long)ptr);
}
/* Unlike other PTR_TO_BTF_ID helpers the btf_id in bpf_kptr_xchg()
* helper is determined dynamically by the verifier. Use BPF_PTR_POISON to
* denote type that verifier will determine.
*/
static const struct bpf_func_proto bpf_kptr_xchg_proto = {
.func = bpf_kptr_xchg,
.gpl_only = false,
.ret_type = RET_PTR_TO_BTF_ID_OR_NULL,
.ret_btf_id = BPF_PTR_POISON,
.arg1_type = ARG_KPTR_XCHG_DEST,
.arg2_type = ARG_PTR_TO_BTF_ID_OR_NULL | OBJ_RELEASE,
.arg2_btf_id = BPF_PTR_POISON,
};
/* Since the upper 8 bits of dynptr->size is reserved, the
* maximum supported size is 2^24 - 1.
*/
#define DYNPTR_MAX_SIZE ((1UL << 24) - 1)
#define DYNPTR_TYPE_SHIFT 28
#define DYNPTR_SIZE_MASK 0xFFFFFF
#define DYNPTR_RDONLY_BIT BIT(31)
bool __bpf_dynptr_is_rdonly(const struct bpf_dynptr_kern *ptr)
{
return ptr->size & DYNPTR_RDONLY_BIT;
}
void bpf_dynptr_set_rdonly(struct bpf_dynptr_kern *ptr)
{
ptr->size |= DYNPTR_RDONLY_BIT;
}
static void bpf_dynptr_set_type(struct bpf_dynptr_kern *ptr, enum bpf_dynptr_type type)
{
ptr->size |= type << DYNPTR_TYPE_SHIFT;
}
static enum bpf_dynptr_type bpf_dynptr_get_type(const struct bpf_dynptr_kern *ptr)
{
return (ptr->size & ~(DYNPTR_RDONLY_BIT)) >> DYNPTR_TYPE_SHIFT;
}
u32 __bpf_dynptr_size(const struct bpf_dynptr_kern *ptr)
{
return ptr->size & DYNPTR_SIZE_MASK;
}
static void bpf_dynptr_set_size(struct bpf_dynptr_kern *ptr, u32 new_size)
{
u32 metadata = ptr->size & ~DYNPTR_SIZE_MASK;
ptr->size = new_size | metadata;
}
int bpf_dynptr_check_size(u32 size)
{
return size > DYNPTR_MAX_SIZE ? -E2BIG : 0;
}
void bpf_dynptr_init(struct bpf_dynptr_kern *ptr, void *data,
enum bpf_dynptr_type type, u32 offset, u32 size)
{
ptr->data = data;
ptr->offset = offset;
ptr->size = size;
bpf_dynptr_set_type(ptr, type);
}
void bpf_dynptr_set_null(struct bpf_dynptr_kern *ptr)
{
memset(ptr, 0, sizeof(*ptr));
}
static int bpf_dynptr_check_off_len(const struct bpf_dynptr_kern *ptr, u32 offset, u32 len)
{
u32 size = __bpf_dynptr_size(ptr);
if (len > size || offset > size - len)
return -E2BIG;
return 0;
}
BPF_CALL_4(bpf_dynptr_from_mem, void *, data, u32, size, u64, flags, struct bpf_dynptr_kern *, ptr)
{
int err;
BTF_TYPE_EMIT(struct bpf_dynptr);
err = bpf_dynptr_check_size(size);
if (err)
goto error;
/* flags is currently unsupported */
if (flags) {
err = -EINVAL;
goto error;
}
bpf_dynptr_init(ptr, data, BPF_DYNPTR_TYPE_LOCAL, 0, size);
return 0;
error:
bpf_dynptr_set_null(ptr);
return err;
}
static const struct bpf_func_proto bpf_dynptr_from_mem_proto = {
.func = bpf_dynptr_from_mem,
.gpl_only = false,
.ret_type = RET_INTEGER,
.arg1_type = ARG_PTR_TO_UNINIT_MEM,
.arg2_type = ARG_CONST_SIZE_OR_ZERO,
.arg3_type = ARG_ANYTHING,
.arg4_type = ARG_PTR_TO_DYNPTR | DYNPTR_TYPE_LOCAL | MEM_UNINIT,
};
BPF_CALL_5(bpf_dynptr_read, void *, dst, u32, len, const struct bpf_dynptr_kern *, src,
u32, offset, u64, flags)
{
enum bpf_dynptr_type type;
int err;
if (!src->data || flags)
return -EINVAL;
err = bpf_dynptr_check_off_len(src, offset, len);
if (err)
return err;
type = bpf_dynptr_get_type(src);
switch (type) {
case BPF_DYNPTR_TYPE_LOCAL:
case BPF_DYNPTR_TYPE_RINGBUF:
/* Source and destination may possibly overlap, hence use memmove to
* copy the data. E.g. bpf_dynptr_from_mem may create two dynptr
* pointing to overlapping PTR_TO_MAP_VALUE regions.
*/
memmove(dst, src->data + src->offset + offset, len);
return 0;
case BPF_DYNPTR_TYPE_SKB:
return __bpf_skb_load_bytes(src->data, src->offset + offset, dst, len);
case BPF_DYNPTR_TYPE_XDP:
return __bpf_xdp_load_bytes(src->data, src->offset + offset, dst, len);
default:
WARN_ONCE(true, "bpf_dynptr_read: unknown dynptr type %d\n", type);
return -EFAULT;
}
}
static const struct bpf_func_proto bpf_dynptr_read_proto = {
.func = bpf_dynptr_read,
.gpl_only = false,
.ret_type = RET_INTEGER,
.arg1_type = ARG_PTR_TO_UNINIT_MEM,
.arg2_type = ARG_CONST_SIZE_OR_ZERO,
.arg3_type = ARG_PTR_TO_DYNPTR | MEM_RDONLY,
.arg4_type = ARG_ANYTHING,
.arg5_type = ARG_ANYTHING,
};
BPF_CALL_5(bpf_dynptr_write, const struct bpf_dynptr_kern *, dst, u32, offset, void *, src,
u32, len, u64, flags)
{
enum bpf_dynptr_type type;
int err;
if (!dst->data || __bpf_dynptr_is_rdonly(dst))
return -EINVAL;
err = bpf_dynptr_check_off_len(dst, offset, len);
if (err)
return err;
type = bpf_dynptr_get_type(dst);
switch (type) {
case BPF_DYNPTR_TYPE_LOCAL:
case BPF_DYNPTR_TYPE_RINGBUF:
if (flags)
return -EINVAL;
/* Source and destination may possibly overlap, hence use memmove to
* copy the data. E.g. bpf_dynptr_from_mem may create two dynptr
* pointing to overlapping PTR_TO_MAP_VALUE regions.
*/
memmove(dst->data + dst->offset + offset, src, len);
return 0;
case BPF_DYNPTR_TYPE_SKB:
return __bpf_skb_store_bytes(dst->data, dst->offset + offset, src, len,
flags);
case BPF_DYNPTR_TYPE_XDP:
if (flags)
return -EINVAL;
return __bpf_xdp_store_bytes(dst->data, dst->offset + offset, src, len);
default:
WARN_ONCE(true, "bpf_dynptr_write: unknown dynptr type %d\n", type);
return -EFAULT;
}
}
static const struct bpf_func_proto bpf_dynptr_write_proto = {
.func = bpf_dynptr_write,
.gpl_only = false,
.ret_type = RET_INTEGER,
.arg1_type = ARG_PTR_TO_DYNPTR | MEM_RDONLY,
.arg2_type = ARG_ANYTHING,
.arg3_type = ARG_PTR_TO_MEM | MEM_RDONLY,
.arg4_type = ARG_CONST_SIZE_OR_ZERO,
.arg5_type = ARG_ANYTHING,
};
BPF_CALL_3(bpf_dynptr_data, const struct bpf_dynptr_kern *, ptr, u32, offset, u32, len)
{
enum bpf_dynptr_type type;
int err;
if (!ptr->data)
return 0;
err = bpf_dynptr_check_off_len(ptr, offset, len);
if (err)
return 0;
if (__bpf_dynptr_is_rdonly(ptr))
return 0;
type = bpf_dynptr_get_type(ptr);
switch (type) {
case BPF_DYNPTR_TYPE_LOCAL:
case BPF_DYNPTR_TYPE_RINGBUF:
return (unsigned long)(ptr->data + ptr->offset + offset);
case BPF_DYNPTR_TYPE_SKB:
case BPF_DYNPTR_TYPE_XDP:
/* skb and xdp dynptrs should use bpf_dynptr_slice / bpf_dynptr_slice_rdwr */
return 0;
default:
WARN_ONCE(true, "bpf_dynptr_data: unknown dynptr type %d\n", type);
return 0;
}
}
static const struct bpf_func_proto bpf_dynptr_data_proto = {
.func = bpf_dynptr_data,
.gpl_only = false,
.ret_type = RET_PTR_TO_DYNPTR_MEM_OR_NULL,
.arg1_type = ARG_PTR_TO_DYNPTR | MEM_RDONLY,
.arg2_type = ARG_ANYTHING,
.arg3_type = ARG_CONST_ALLOC_SIZE_OR_ZERO,
};
const struct bpf_func_proto bpf_get_current_task_proto __weak;
const struct bpf_func_proto bpf_get_current_task_btf_proto __weak;
const struct bpf_func_proto bpf_probe_read_user_proto __weak;
const struct bpf_func_proto bpf_probe_read_user_str_proto __weak;
const struct bpf_func_proto bpf_probe_read_kernel_proto __weak;
const struct bpf_func_proto bpf_probe_read_kernel_str_proto __weak;
const struct bpf_func_proto bpf_task_pt_regs_proto __weak;
const struct bpf_func_proto *
bpf_base_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
{
switch (func_id) {
case BPF_FUNC_map_lookup_elem:
return &bpf_map_lookup_elem_proto;
case BPF_FUNC_map_update_elem:
return &bpf_map_update_elem_proto;
case BPF_FUNC_map_delete_elem:
return &bpf_map_delete_elem_proto;
case BPF_FUNC_map_push_elem:
return &bpf_map_push_elem_proto;
case BPF_FUNC_map_pop_elem:
return &bpf_map_pop_elem_proto;
case BPF_FUNC_map_peek_elem:
return &bpf_map_peek_elem_proto;
case BPF_FUNC_map_lookup_percpu_elem:
return &bpf_map_lookup_percpu_elem_proto;
case BPF_FUNC_get_prandom_u32:
return &bpf_get_prandom_u32_proto;
case BPF_FUNC_get_smp_processor_id:
return &bpf_get_raw_smp_processor_id_proto;
case BPF_FUNC_get_numa_node_id:
return &bpf_get_numa_node_id_proto;
case BPF_FUNC_tail_call:
return &bpf_tail_call_proto;
case BPF_FUNC_ktime_get_ns:
return &bpf_ktime_get_ns_proto;
case BPF_FUNC_ktime_get_boot_ns:
return &bpf_ktime_get_boot_ns_proto;
case BPF_FUNC_ktime_get_tai_ns:
return &bpf_ktime_get_tai_ns_proto;
case BPF_FUNC_ringbuf_output:
return &bpf_ringbuf_output_proto;
case BPF_FUNC_ringbuf_reserve:
return &bpf_ringbuf_reserve_proto;
case BPF_FUNC_ringbuf_submit:
return &bpf_ringbuf_submit_proto;
case BPF_FUNC_ringbuf_discard:
return &bpf_ringbuf_discard_proto;
case BPF_FUNC_ringbuf_query:
return &bpf_ringbuf_query_proto;
case BPF_FUNC_strncmp:
return &bpf_strncmp_proto;
case BPF_FUNC_strtol:
return &bpf_strtol_proto;
case BPF_FUNC_strtoul:
return &bpf_strtoul_proto;
case BPF_FUNC_get_current_pid_tgid:
return &bpf_get_current_pid_tgid_proto;
case BPF_FUNC_get_ns_current_pid_tgid:
return &bpf_get_ns_current_pid_tgid_proto;
default:
break;
}
if (!bpf_token_capable(prog->aux->token, CAP_BPF))
return NULL;
switch (func_id) {
case BPF_FUNC_spin_lock:
return &bpf_spin_lock_proto;
case BPF_FUNC_spin_unlock:
return &bpf_spin_unlock_proto;
case BPF_FUNC_jiffies64:
return &bpf_jiffies64_proto;
case BPF_FUNC_per_cpu_ptr:
return &bpf_per_cpu_ptr_proto;
case BPF_FUNC_this_cpu_ptr:
return &bpf_this_cpu_ptr_proto;
case BPF_FUNC_timer_init:
return &bpf_timer_init_proto;
case BPF_FUNC_timer_set_callback:
return &bpf_timer_set_callback_proto;
case BPF_FUNC_timer_start:
return &bpf_timer_start_proto;
case BPF_FUNC_timer_cancel:
return &bpf_timer_cancel_proto;
case BPF_FUNC_kptr_xchg:
return &bpf_kptr_xchg_proto;
case BPF_FUNC_for_each_map_elem:
return &bpf_for_each_map_elem_proto;
case BPF_FUNC_loop:
return &bpf_loop_proto;
case BPF_FUNC_user_ringbuf_drain:
return &bpf_user_ringbuf_drain_proto;
case BPF_FUNC_ringbuf_reserve_dynptr:
return &bpf_ringbuf_reserve_dynptr_proto;
case BPF_FUNC_ringbuf_submit_dynptr:
return &bpf_ringbuf_submit_dynptr_proto;
case BPF_FUNC_ringbuf_discard_dynptr:
return &bpf_ringbuf_discard_dynptr_proto;
case BPF_FUNC_dynptr_from_mem:
return &bpf_dynptr_from_mem_proto;
case BPF_FUNC_dynptr_read:
return &bpf_dynptr_read_proto;
case BPF_FUNC_dynptr_write:
return &bpf_dynptr_write_proto;
case BPF_FUNC_dynptr_data:
return &bpf_dynptr_data_proto;
#ifdef CONFIG_CGROUPS
case BPF_FUNC_cgrp_storage_get:
return &bpf_cgrp_storage_get_proto;
case BPF_FUNC_cgrp_storage_delete:
return &bpf_cgrp_storage_delete_proto;
case BPF_FUNC_get_current_cgroup_id:
return &bpf_get_current_cgroup_id_proto;
case BPF_FUNC_get_current_ancestor_cgroup_id:
return &bpf_get_current_ancestor_cgroup_id_proto;
#endif
default:
break;
}
if (!bpf_token_capable(prog->aux->token, CAP_PERFMON))
return NULL;
switch (func_id) {
case BPF_FUNC_trace_printk:
return bpf_get_trace_printk_proto();
case BPF_FUNC_get_current_task:
return &bpf_get_current_task_proto;
case BPF_FUNC_get_current_task_btf:
return &bpf_get_current_task_btf_proto;
case BPF_FUNC_probe_read_user:
return &bpf_probe_read_user_proto;
case BPF_FUNC_probe_read_kernel:
return security_locked_down(LOCKDOWN_BPF_READ_KERNEL) < 0 ?
NULL : &bpf_probe_read_kernel_proto;
case BPF_FUNC_probe_read_user_str:
return &bpf_probe_read_user_str_proto;
case BPF_FUNC_probe_read_kernel_str:
return security_locked_down(LOCKDOWN_BPF_READ_KERNEL) < 0 ?
NULL : &bpf_probe_read_kernel_str_proto;
case BPF_FUNC_snprintf_btf:
return &bpf_snprintf_btf_proto;
case BPF_FUNC_snprintf:
return &bpf_snprintf_proto;
case BPF_FUNC_task_pt_regs:
return &bpf_task_pt_regs_proto;
case BPF_FUNC_trace_vprintk:
return bpf_get_trace_vprintk_proto();
default:
return NULL;
}
}
EXPORT_SYMBOL_GPL(bpf_base_func_proto);
void bpf_list_head_free(const struct btf_field *field, void *list_head,
struct bpf_spin_lock *spin_lock)
{
struct list_head *head = list_head, *orig_head = list_head;
BUILD_BUG_ON(sizeof(struct list_head) > sizeof(struct bpf_list_head));
BUILD_BUG_ON(__alignof__(struct list_head) > __alignof__(struct bpf_list_head));
/* Do the actual list draining outside the lock to not hold the lock for
* too long, and also prevent deadlocks if tracing programs end up
* executing on entry/exit of functions called inside the critical
* section, and end up doing map ops that call bpf_list_head_free for
* the same map value again.
*/
__bpf_spin_lock_irqsave(spin_lock);
if (!head->next || list_empty(head))
goto unlock;
head = head->next;
unlock:
INIT_LIST_HEAD(orig_head);
__bpf_spin_unlock_irqrestore(spin_lock);
while (head != orig_head) {
void *obj = head;
obj -= field->graph_root.node_offset;
head = head->next;
/* The contained type can also have resources, including a
* bpf_list_head which needs to be freed.
*/
migrate_disable();
__bpf_obj_drop_impl(obj, field->graph_root.value_rec, false);
migrate_enable();
}
}
/* Like rbtree_postorder_for_each_entry_safe, but 'pos' and 'n' are
* 'rb_node *', so field name of rb_node within containing struct is not
* needed.
*
* Since bpf_rb_tree's node type has a corresponding struct btf_field with
* graph_root.node_offset, it's not necessary to know field name
* or type of node struct
*/
#define bpf_rbtree_postorder_for_each_entry_safe(pos, n, root) \
for (pos = rb_first_postorder(root); \
pos && ({ n = rb_next_postorder(pos); 1; }); \
pos = n)
void bpf_rb_root_free(const struct btf_field *field, void *rb_root,
struct bpf_spin_lock *spin_lock)
{
struct rb_root_cached orig_root, *root = rb_root;
struct rb_node *pos, *n;
void *obj;
BUILD_BUG_ON(sizeof(struct rb_root_cached) > sizeof(struct bpf_rb_root));
BUILD_BUG_ON(__alignof__(struct rb_root_cached) > __alignof__(struct bpf_rb_root));
__bpf_spin_lock_irqsave(spin_lock);
orig_root = *root;
*root = RB_ROOT_CACHED;
__bpf_spin_unlock_irqrestore(spin_lock);
bpf_rbtree_postorder_for_each_entry_safe(pos, n, &orig_root.rb_root) {
obj = pos;
obj -= field->graph_root.node_offset;
migrate_disable();
__bpf_obj_drop_impl(obj, field->graph_root.value_rec, false);
migrate_enable();
}
}
__bpf_kfunc_start_defs();
__bpf_kfunc void *bpf_obj_new_impl(u64 local_type_id__k, void *meta__ign)
{
struct btf_struct_meta *meta = meta__ign;
u64 size = local_type_id__k;
void *p;
p = bpf_mem_alloc(&bpf_global_ma, size);
if (!p)
return NULL;
if (meta)
bpf_obj_init(meta->record, p);
return p;
}
__bpf_kfunc void *bpf_percpu_obj_new_impl(u64 local_type_id__k, void *meta__ign)
{
u64 size = local_type_id__k;
/* The verifier has ensured that meta__ign must be NULL */
return bpf_mem_alloc(&bpf_global_percpu_ma, size);
}
/* Must be called under migrate_disable(), as required by bpf_mem_free */
void __bpf_obj_drop_impl(void *p, const struct btf_record *rec, bool percpu)
{
struct bpf_mem_alloc *ma;
if (rec && rec->refcount_off >= 0 &&
!refcount_dec_and_test((refcount_t *)(p + rec->refcount_off))) {
/* Object is refcounted and refcount_dec didn't result in 0
* refcount. Return without freeing the object
*/
return;
}
if (rec)
bpf_obj_free_fields(rec, p);
if (percpu)
ma = &bpf_global_percpu_ma;
else
ma = &bpf_global_ma;
bpf_mem_free_rcu(ma, p);
}
__bpf_kfunc void bpf_obj_drop_impl(void *p__alloc, void *meta__ign)
{
struct btf_struct_meta *meta = meta__ign;
void *p = p__alloc;
__bpf_obj_drop_impl(p, meta ? meta->record : NULL, false);
}
__bpf_kfunc void bpf_percpu_obj_drop_impl(void *p__alloc, void *meta__ign)
{
/* The verifier has ensured that meta__ign must be NULL */
bpf_mem_free_rcu(&bpf_global_percpu_ma, p__alloc);
}
__bpf_kfunc void *bpf_refcount_acquire_impl(void *p__refcounted_kptr, void *meta__ign)
{
struct btf_struct_meta *meta = meta__ign;
struct bpf_refcount *ref;
/* Could just cast directly to refcount_t *, but need some code using
* bpf_refcount type so that it is emitted in vmlinux BTF
*/
ref = (struct bpf_refcount *)(p__refcounted_kptr + meta->record->refcount_off);
if (!refcount_inc_not_zero((refcount_t *)ref))
return NULL;
/* Verifier strips KF_RET_NULL if input is owned ref, see is_kfunc_ret_null
* in verifier.c
*/
return (void *)p__refcounted_kptr;
}
static int __bpf_list_add(struct bpf_list_node_kern *node,
struct bpf_list_head *head,
bool tail, struct btf_record *rec, u64 off)
{
struct list_head *n = &node->list_head, *h = (void *)head;
/* If list_head was 0-initialized by map, bpf_obj_init_field wasn't
* called on its fields, so init here
*/
if (unlikely(!h->next))
INIT_LIST_HEAD(h);
/* node->owner != NULL implies !list_empty(n), no need to separately
* check the latter
*/
if (cmpxchg(&node->owner, NULL, BPF_PTR_POISON)) {
/* Only called from BPF prog, no need to migrate_disable */
__bpf_obj_drop_impl((void *)n - off, rec, false);
return -EINVAL;
}
tail ? list_add_tail(n, h) : list_add(n, h);
WRITE_ONCE(node->owner, head);
return 0;
}
__bpf_kfunc int bpf_list_push_front_impl(struct bpf_list_head *head,
struct bpf_list_node *node,
void *meta__ign, u64 off)
{
struct bpf_list_node_kern *n = (void *)node;
struct btf_struct_meta *meta = meta__ign;
return __bpf_list_add(n, head, false, meta ? meta->record : NULL, off);
}
__bpf_kfunc int bpf_list_push_back_impl(struct bpf_list_head *head,
struct bpf_list_node *node,
void *meta__ign, u64 off)
{
struct bpf_list_node_kern *n = (void *)node;
struct btf_struct_meta *meta = meta__ign;
return __bpf_list_add(n, head, true, meta ? meta->record : NULL, off);
}
static struct bpf_list_node *__bpf_list_del(struct bpf_list_head *head, bool tail)
{
struct list_head *n, *h = (void *)head;
struct bpf_list_node_kern *node;
/* If list_head was 0-initialized by map, bpf_obj_init_field wasn't
* called on its fields, so init here
*/
if (unlikely(!h->next))
INIT_LIST_HEAD(h);
if (list_empty(h))
return NULL;
n = tail ? h->prev : h->next;
node = container_of(n, struct bpf_list_node_kern, list_head);
if (WARN_ON_ONCE(READ_ONCE(node->owner) != head))
return NULL;
list_del_init(n);
WRITE_ONCE(node->owner, NULL);
return (struct bpf_list_node *)n;
}
__bpf_kfunc struct bpf_list_node *bpf_list_pop_front(struct bpf_list_head *head)
{
return __bpf_list_del(head, false);
}
__bpf_kfunc struct bpf_list_node *bpf_list_pop_back(struct bpf_list_head *head)
{
return __bpf_list_del(head, true);
}
__bpf_kfunc struct bpf_rb_node *bpf_rbtree_remove(struct bpf_rb_root *root,
struct bpf_rb_node *node)
{
struct bpf_rb_node_kern *node_internal = (struct bpf_rb_node_kern *)node;
struct rb_root_cached *r = (struct rb_root_cached *)root;
struct rb_node *n = &node_internal->rb_node;
/* node_internal->owner != root implies either RB_EMPTY_NODE(n) or
* n is owned by some other tree. No need to check RB_EMPTY_NODE(n)
*/
if (READ_ONCE(node_internal->owner) != root)
return NULL;
rb_erase_cached(n, r);
RB_CLEAR_NODE(n);
WRITE_ONCE(node_internal->owner, NULL);
return (struct bpf_rb_node *)n;
}
/* Need to copy rbtree_add_cached's logic here because our 'less' is a BPF
* program
*/
static int __bpf_rbtree_add(struct bpf_rb_root *root,
struct bpf_rb_node_kern *node,
void *less, struct btf_record *rec, u64 off)
{
struct rb_node **link = &((struct rb_root_cached *)root)->rb_root.rb_node;
struct rb_node *parent = NULL, *n = &node->rb_node;
bpf_callback_t cb = (bpf_callback_t)less;
bool leftmost = true;
/* node->owner != NULL implies !RB_EMPTY_NODE(n), no need to separately
* check the latter
*/
if (cmpxchg(&node->owner, NULL, BPF_PTR_POISON)) {
/* Only called from BPF prog, no need to migrate_disable */
__bpf_obj_drop_impl((void *)n - off, rec, false);
return -EINVAL;
}
while (*link) {
parent = *link;
if (cb((uintptr_t)node, (uintptr_t)parent, 0, 0, 0)) {
link = &parent->rb_left;
} else {
link = &parent->rb_right;
leftmost = false;
}
}
rb_link_node(n, parent, link);
rb_insert_color_cached(n, (struct rb_root_cached *)root, leftmost);
WRITE_ONCE(node->owner, root);
return 0;
}
__bpf_kfunc int bpf_rbtree_add_impl(struct bpf_rb_root *root, struct bpf_rb_node *node,
bool (less)(struct bpf_rb_node *a, const struct bpf_rb_node *b),
void *meta__ign, u64 off)
{
struct btf_struct_meta *meta = meta__ign;
struct bpf_rb_node_kern *n = (void *)node;
return __bpf_rbtree_add(root, n, (void *)less, meta ? meta->record : NULL, off);
}
__bpf_kfunc struct bpf_rb_node *bpf_rbtree_first(struct bpf_rb_root *root)
{
struct rb_root_cached *r = (struct rb_root_cached *)root;
return (struct bpf_rb_node *)rb_first_cached(r);
}
/**
* bpf_task_acquire - Acquire a reference to a task. A task acquired by this
* kfunc which is not stored in a map as a kptr, must be released by calling
* bpf_task_release().
* @p: The task on which a reference is being acquired.
*/
__bpf_kfunc struct task_struct *bpf_task_acquire(struct task_struct *p)
{
if (refcount_inc_not_zero(&p->rcu_users))
return p;
return NULL;
}
/**
* bpf_task_release - Release the reference acquired on a task.
* @p: The task on which a reference is being released.
*/
__bpf_kfunc void bpf_task_release(struct task_struct *p)
{
put_task_struct_rcu_user(p);
}
__bpf_kfunc void bpf_task_release_dtor(void *p)
{
put_task_struct_rcu_user(p);
}
CFI_NOSEAL(bpf_task_release_dtor);
#ifdef CONFIG_CGROUPS
/**
* bpf_cgroup_acquire - Acquire a reference to a cgroup. A cgroup acquired by
* this kfunc which is not stored in a map as a kptr, must be released by
* calling bpf_cgroup_release().
* @cgrp: The cgroup on which a reference is being acquired.
*/
__bpf_kfunc struct cgroup *bpf_cgroup_acquire(struct cgroup *cgrp)
{
return cgroup_tryget(cgrp) ? cgrp : NULL;
}
/**
* bpf_cgroup_release - Release the reference acquired on a cgroup.
* If this kfunc is invoked in an RCU read region, the cgroup is guaranteed to
* not be freed until the current grace period has ended, even if its refcount
* drops to 0.
* @cgrp: The cgroup on which a reference is being released.
*/
__bpf_kfunc void bpf_cgroup_release(struct cgroup *cgrp)
{
cgroup_put(cgrp);
}
__bpf_kfunc void bpf_cgroup_release_dtor(void *cgrp)
{
cgroup_put(cgrp);
}
CFI_NOSEAL(bpf_cgroup_release_dtor);
/**
* bpf_cgroup_ancestor - Perform a lookup on an entry in a cgroup's ancestor
* array. A cgroup returned by this kfunc which is not subsequently stored in a
* map, must be released by calling bpf_cgroup_release().
* @cgrp: The cgroup for which we're performing a lookup.
* @level: The level of ancestor to look up.
*/
__bpf_kfunc struct cgroup *bpf_cgroup_ancestor(struct cgroup *cgrp, int level)
{
struct cgroup *ancestor;
if (level > cgrp->level || level < 0)
return NULL;
/* cgrp's refcnt could be 0 here, but ancestors can still be accessed */
ancestor = cgrp->ancestors[level];
if (!cgroup_tryget(ancestor))
return NULL;
return ancestor;
}
/**
* bpf_cgroup_from_id - Find a cgroup from its ID. A cgroup returned by this
* kfunc which is not subsequently stored in a map, must be released by calling
* bpf_cgroup_release().
* @cgid: cgroup id.
*/
__bpf_kfunc struct cgroup *bpf_cgroup_from_id(u64 cgid)
{
struct cgroup *cgrp;
cgrp = cgroup_get_from_id(cgid);
if (IS_ERR(cgrp))
return NULL;
return cgrp;
}
/**
* bpf_task_under_cgroup - wrap task_under_cgroup_hierarchy() as a kfunc, test
* task's membership of cgroup ancestry.
* @task: the task to be tested
* @ancestor: possible ancestor of @task's cgroup
*
* Tests whether @task's default cgroup hierarchy is a descendant of @ancestor.
* It follows all the same rules as cgroup_is_descendant, and only applies
* to the default hierarchy.
*/
__bpf_kfunc long bpf_task_under_cgroup(struct task_struct *task,
struct cgroup *ancestor)
{
long ret;
rcu_read_lock();
ret = task_under_cgroup_hierarchy(task, ancestor);
rcu_read_unlock();
return ret;
}
BPF_CALL_2(bpf_current_task_under_cgroup, struct bpf_map *, map, u32, idx)
{
struct bpf_array *array = container_of(map, struct bpf_array, map);
struct cgroup *cgrp;
if (unlikely(idx >= array->map.max_entries))
return -E2BIG;
cgrp = READ_ONCE(array->ptrs[idx]);
if (unlikely(!cgrp))
return -EAGAIN;
return task_under_cgroup_hierarchy(current, cgrp);
}
const struct bpf_func_proto bpf_current_task_under_cgroup_proto = {
.func = bpf_current_task_under_cgroup,
.gpl_only = false,
.ret_type = RET_INTEGER,
.arg1_type = ARG_CONST_MAP_PTR,
.arg2_type = ARG_ANYTHING,
};
/**
* bpf_task_get_cgroup1 - Acquires the associated cgroup of a task within a
* specific cgroup1 hierarchy. The cgroup1 hierarchy is identified by its
* hierarchy ID.
* @task: The target task
* @hierarchy_id: The ID of a cgroup1 hierarchy
*
* On success, the cgroup is returen. On failure, NULL is returned.
*/
__bpf_kfunc struct cgroup *
bpf_task_get_cgroup1(struct task_struct *task, int hierarchy_id)
{
struct cgroup *cgrp = task_get_cgroup1(task, hierarchy_id);
if (IS_ERR(cgrp))
return NULL;
return cgrp;
}
#endif /* CONFIG_CGROUPS */
/**
* bpf_task_from_pid - Find a struct task_struct from its pid by looking it up
* in the root pid namespace idr. If a task is returned, it must either be
* stored in a map, or released with bpf_task_release().
* @pid: The pid of the task being looked up.
*/
__bpf_kfunc struct task_struct *bpf_task_from_pid(s32 pid)
{
struct task_struct *p;
rcu_read_lock();
p = find_task_by_pid_ns(pid, &init_pid_ns);
if (p)
p = bpf_task_acquire(p);
rcu_read_unlock();
return p;
}
/**
* bpf_dynptr_slice() - Obtain a read-only pointer to the dynptr data.
* @p: The dynptr whose data slice to retrieve
* @offset: Offset into the dynptr
* @buffer__opt: User-provided buffer to copy contents into. May be NULL
* @buffer__szk: Size (in bytes) of the buffer if present. This is the
* length of the requested slice. This must be a constant.
*
* For non-skb and non-xdp type dynptrs, there is no difference between
* bpf_dynptr_slice and bpf_dynptr_data.
*
* If buffer__opt is NULL, the call will fail if buffer_opt was needed.
*
* If the intention is to write to the data slice, please use
* bpf_dynptr_slice_rdwr.
*
* The user must check that the returned pointer is not null before using it.
*
* Please note that in the case of skb and xdp dynptrs, bpf_dynptr_slice
* does not change the underlying packet data pointers, so a call to
* bpf_dynptr_slice will not invalidate any ctx->data/data_end pointers in
* the bpf program.
*
* Return: NULL if the call failed (eg invalid dynptr), pointer to a read-only
* data slice (can be either direct pointer to the data or a pointer to the user
* provided buffer, with its contents containing the data, if unable to obtain
* direct pointer)
*/
__bpf_kfunc void *bpf_dynptr_slice(const struct bpf_dynptr *p, u32 offset,
void *buffer__opt, u32 buffer__szk)
{
const struct bpf_dynptr_kern *ptr = (struct bpf_dynptr_kern *)p;
enum bpf_dynptr_type type;
u32 len = buffer__szk;
int err;
if (!ptr->data)
return NULL;
err = bpf_dynptr_check_off_len(ptr, offset, len);
if (err)
return NULL;
type = bpf_dynptr_get_type(ptr);
switch (type) {
case BPF_DYNPTR_TYPE_LOCAL:
case BPF_DYNPTR_TYPE_RINGBUF:
return ptr->data + ptr->offset + offset;
case BPF_DYNPTR_TYPE_SKB:
if (buffer__opt)
return skb_header_pointer(ptr->data, ptr->offset + offset, len, buffer__opt);
else
return skb_pointer_if_linear(ptr->data, ptr->offset + offset, len);
case BPF_DYNPTR_TYPE_XDP:
{
void *xdp_ptr = bpf_xdp_pointer(ptr->data, ptr->offset + offset, len);
if (!IS_ERR_OR_NULL(xdp_ptr))
return xdp_ptr;
if (!buffer__opt)
return NULL;
bpf_xdp_copy_buf(ptr->data, ptr->offset + offset, buffer__opt, len, false);
return buffer__opt;
}
default:
WARN_ONCE(true, "unknown dynptr type %d\n", type);
return NULL;
}
}
/**
* bpf_dynptr_slice_rdwr() - Obtain a writable pointer to the dynptr data.
* @p: The dynptr whose data slice to retrieve
* @offset: Offset into the dynptr
* @buffer__opt: User-provided buffer to copy contents into. May be NULL
* @buffer__szk: Size (in bytes) of the buffer if present. This is the
* length of the requested slice. This must be a constant.
*
* For non-skb and non-xdp type dynptrs, there is no difference between
* bpf_dynptr_slice and bpf_dynptr_data.
*
* If buffer__opt is NULL, the call will fail if buffer_opt was needed.
*
* The returned pointer is writable and may point to either directly the dynptr
* data at the requested offset or to the buffer if unable to obtain a direct
* data pointer to (example: the requested slice is to the paged area of an skb
* packet). In the case where the returned pointer is to the buffer, the user
* is responsible for persisting writes through calling bpf_dynptr_write(). This
* usually looks something like this pattern:
*
* struct eth_hdr *eth = bpf_dynptr_slice_rdwr(&dynptr, 0, buffer, sizeof(buffer));
* if (!eth)
* return TC_ACT_SHOT;
*
* // mutate eth header //
*
* if (eth == buffer)
* bpf_dynptr_write(&ptr, 0, buffer, sizeof(buffer), 0);
*
* Please note that, as in the example above, the user must check that the
* returned pointer is not null before using it.
*
* Please also note that in the case of skb and xdp dynptrs, bpf_dynptr_slice_rdwr
* does not change the underlying packet data pointers, so a call to
* bpf_dynptr_slice_rdwr will not invalidate any ctx->data/data_end pointers in
* the bpf program.
*
* Return: NULL if the call failed (eg invalid dynptr), pointer to a
* data slice (can be either direct pointer to the data or a pointer to the user
* provided buffer, with its contents containing the data, if unable to obtain
* direct pointer)
*/
__bpf_kfunc void *bpf_dynptr_slice_rdwr(const struct bpf_dynptr *p, u32 offset,
void *buffer__opt, u32 buffer__szk)
{
const struct bpf_dynptr_kern *ptr = (struct bpf_dynptr_kern *)p;
if (!ptr->data || __bpf_dynptr_is_rdonly(ptr))
return NULL;
/* bpf_dynptr_slice_rdwr is the same logic as bpf_dynptr_slice.
*
* For skb-type dynptrs, it is safe to write into the returned pointer
* if the bpf program allows skb data writes. There are two possibilities
* that may occur when calling bpf_dynptr_slice_rdwr:
*
* 1) The requested slice is in the head of the skb. In this case, the
* returned pointer is directly to skb data, and if the skb is cloned, the
* verifier will have uncloned it (see bpf_unclone_prologue()) already.
* The pointer can be directly written into.
*
* 2) Some portion of the requested slice is in the paged buffer area.
* In this case, the requested data will be copied out into the buffer
* and the returned pointer will be a pointer to the buffer. The skb
* will not be pulled. To persist the write, the user will need to call
* bpf_dynptr_write(), which will pull the skb and commit the write.
*
* Similarly for xdp programs, if the requested slice is not across xdp
* fragments, then a direct pointer will be returned, otherwise the data
* will be copied out into the buffer and the user will need to call
* bpf_dynptr_write() to commit changes.
*/
return bpf_dynptr_slice(p, offset, buffer__opt, buffer__szk);
}
__bpf_kfunc int bpf_dynptr_adjust(const struct bpf_dynptr *p, u32 start, u32 end)
{
struct bpf_dynptr_kern *ptr = (struct bpf_dynptr_kern *)p;
u32 size;
if (!ptr->data || start > end)
return -EINVAL;
size = __bpf_dynptr_size(ptr);
if (start > size || end > size)
return -ERANGE;
ptr->offset += start;
bpf_dynptr_set_size(ptr, end - start);
return 0;
}
__bpf_kfunc bool bpf_dynptr_is_null(const struct bpf_dynptr *p)
{
struct bpf_dynptr_kern *ptr = (struct bpf_dynptr_kern *)p;
return !ptr->data;
}
__bpf_kfunc bool bpf_dynptr_is_rdonly(const struct bpf_dynptr *p)
{
struct bpf_dynptr_kern *ptr = (struct bpf_dynptr_kern *)p;
if (!ptr->data)
return false;
return __bpf_dynptr_is_rdonly(ptr);
}
__bpf_kfunc __u32 bpf_dynptr_size(const struct bpf_dynptr *p)
{
struct bpf_dynptr_kern *ptr = (struct bpf_dynptr_kern *)p;
if (!ptr->data)
return -EINVAL;
return __bpf_dynptr_size(ptr);
}
__bpf_kfunc int bpf_dynptr_clone(const struct bpf_dynptr *p,
struct bpf_dynptr *clone__uninit)
{
struct bpf_dynptr_kern *clone = (struct bpf_dynptr_kern *)clone__uninit;
struct bpf_dynptr_kern *ptr = (struct bpf_dynptr_kern *)p;
if (!ptr->data) {
bpf_dynptr_set_null(clone);
return -EINVAL;
}
*clone = *ptr;
return 0;
}
__bpf_kfunc void *bpf_cast_to_kern_ctx(void *obj)
{
return obj;
}
__bpf_kfunc void *bpf_rdonly_cast(const void *obj__ign, u32 btf_id__k)
{
return (void *)obj__ign;
}
__bpf_kfunc void bpf_rcu_read_lock(void)
{
rcu_read_lock();
}
__bpf_kfunc void bpf_rcu_read_unlock(void)
{
rcu_read_unlock();
}
struct bpf_throw_ctx {
struct bpf_prog_aux *aux;
u64 sp;
u64 bp;
int cnt;
};
static bool bpf_stack_walker(void *cookie, u64 ip, u64 sp, u64 bp)
{
struct bpf_throw_ctx *ctx = cookie;
struct bpf_prog *prog;
if (!is_bpf_text_address(ip))
return !ctx->cnt;
prog = bpf_prog_ksym_find(ip);
ctx->cnt++;
if (bpf_is_subprog(prog))
return true;
ctx->aux = prog->aux;
ctx->sp = sp;
ctx->bp = bp;
return false;
}
__bpf_kfunc void bpf_throw(u64 cookie)
{
struct bpf_throw_ctx ctx = {};
arch_bpf_stack_walk(bpf_stack_walker, &ctx);
WARN_ON_ONCE(!ctx.aux);
if (ctx.aux)
WARN_ON_ONCE(!ctx.aux->exception_boundary);
WARN_ON_ONCE(!ctx.bp);
WARN_ON_ONCE(!ctx.cnt);
/* Prevent KASAN false positives for CONFIG_KASAN_STACK by unpoisoning
* deeper stack depths than ctx.sp as we do not return from bpf_throw,
* which skips compiler generated instrumentation to do the same.
*/
kasan_unpoison_task_stack_below((void *)(long)ctx.sp);
ctx.aux->bpf_exception_cb(cookie, ctx.sp, ctx.bp, 0, 0);
WARN(1, "A call to BPF exception callback should never return\n");
}
__bpf_kfunc int bpf_wq_init(struct bpf_wq *wq, void *p__map, unsigned int flags)
{
struct bpf_async_kern *async = (struct bpf_async_kern *)wq;
struct bpf_map *map = p__map;
BUILD_BUG_ON(sizeof(struct bpf_async_kern) > sizeof(struct bpf_wq));
BUILD_BUG_ON(__alignof__(struct bpf_async_kern) != __alignof__(struct bpf_wq));
if (flags)
return -EINVAL;
return __bpf_async_init(async, map, flags, BPF_ASYNC_TYPE_WQ);
}
__bpf_kfunc int bpf_wq_start(struct bpf_wq *wq, unsigned int flags)
{
struct bpf_async_kern *async = (struct bpf_async_kern *)wq;
struct bpf_work *w;
if (in_nmi())
return -EOPNOTSUPP;
if (flags)
return -EINVAL;
w = READ_ONCE(async->work);
if (!w || !READ_ONCE(w->cb.prog))
return -EINVAL;
schedule_work(&w->work);
return 0;
}
__bpf_kfunc int bpf_wq_set_callback_impl(struct bpf_wq *wq,
int (callback_fn)(void *map, int *key, void *value),
unsigned int flags,
void *aux__ign)
{
struct bpf_prog_aux *aux = (struct bpf_prog_aux *)aux__ign;
struct bpf_async_kern *async = (struct bpf_async_kern *)wq;
if (flags)
return -EINVAL;
return __bpf_async_set_callback(async, callback_fn, aux, flags, BPF_ASYNC_TYPE_WQ);
}
__bpf_kfunc void bpf_preempt_disable(void)
{
preempt_disable();
}
__bpf_kfunc void bpf_preempt_enable(void)
{
preempt_enable();
}
struct bpf_iter_bits {
__u64 __opaque[2];
} __aligned(8);
struct bpf_iter_bits_kern {
union {
unsigned long *bits;
unsigned long bits_copy;
};
u32 nr_bits;
int bit;
} __aligned(8);
/**
* bpf_iter_bits_new() - Initialize a new bits iterator for a given memory area
* @it: The new bpf_iter_bits to be created
* @unsafe_ptr__ign: A pointer pointing to a memory area to be iterated over
* @nr_words: The size of the specified memory area, measured in 8-byte units.
* Due to the limitation of memalloc, it can't be greater than 512.
*
* This function initializes a new bpf_iter_bits structure for iterating over
* a memory area which is specified by the @unsafe_ptr__ign and @nr_words. It
* copies the data of the memory area to the newly created bpf_iter_bits @it for
* subsequent iteration operations.
*
* On success, 0 is returned. On failure, ERR is returned.
*/
__bpf_kfunc int
bpf_iter_bits_new(struct bpf_iter_bits *it, const u64 *unsafe_ptr__ign, u32 nr_words)
{
struct bpf_iter_bits_kern *kit = (void *)it;
u32 nr_bytes = nr_words * sizeof(u64);
u32 nr_bits = BYTES_TO_BITS(nr_bytes);
int err;
BUILD_BUG_ON(sizeof(struct bpf_iter_bits_kern) != sizeof(struct bpf_iter_bits));
BUILD_BUG_ON(__alignof__(struct bpf_iter_bits_kern) !=
__alignof__(struct bpf_iter_bits));
kit->nr_bits = 0;
kit->bits_copy = 0;
kit->bit = -1;
if (!unsafe_ptr__ign || !nr_words)
return -EINVAL;
/* Optimization for u64 mask */
if (nr_bits == 64) {
err = bpf_probe_read_kernel_common(&kit->bits_copy, nr_bytes, unsafe_ptr__ign);
if (err)
return -EFAULT;
kit->nr_bits = nr_bits;
return 0;
}
/* Fallback to memalloc */
kit->bits = bpf_mem_alloc(&bpf_global_ma, nr_bytes);
if (!kit->bits)
return -ENOMEM;
err = bpf_probe_read_kernel_common(kit->bits, nr_bytes, unsafe_ptr__ign);
if (err) {
bpf_mem_free(&bpf_global_ma, kit->bits);
return err;
}
kit->nr_bits = nr_bits;
return 0;
}
/**
* bpf_iter_bits_next() - Get the next bit in a bpf_iter_bits
* @it: The bpf_iter_bits to be checked
*
* This function returns a pointer to a number representing the value of the
* next bit in the bits.
*
* If there are no further bits available, it returns NULL.
*/
__bpf_kfunc int *bpf_iter_bits_next(struct bpf_iter_bits *it)
{
struct bpf_iter_bits_kern *kit = (void *)it;
u32 nr_bits = kit->nr_bits;
const unsigned long *bits;
int bit;
if (nr_bits == 0)
return NULL;
bits = nr_bits == 64 ? &kit->bits_copy : kit->bits;
bit = find_next_bit(bits, nr_bits, kit->bit + 1);
if (bit >= nr_bits) {
kit->nr_bits = 0;
return NULL;
}
kit->bit = bit;
return &kit->bit;
}
/**
* bpf_iter_bits_destroy() - Destroy a bpf_iter_bits
* @it: The bpf_iter_bits to be destroyed
*
* Destroy the resource associated with the bpf_iter_bits.
*/
__bpf_kfunc void bpf_iter_bits_destroy(struct bpf_iter_bits *it)
{
struct bpf_iter_bits_kern *kit = (void *)it;
if (kit->nr_bits <= 64)
return;
bpf_mem_free(&bpf_global_ma, kit->bits);
}
/**
* bpf_copy_from_user_str() - Copy a string from an unsafe user address
* @dst: Destination address, in kernel space. This buffer must be
* at least @dst__sz bytes long.
* @dst__sz: Maximum number of bytes to copy, includes the trailing NUL.
* @unsafe_ptr__ign: Source address, in user space.
* @flags: The only supported flag is BPF_F_PAD_ZEROS
*
* Copies a NUL-terminated string from userspace to BPF space. If user string is
* too long this will still ensure zero termination in the dst buffer unless
* buffer size is 0.
*
* If BPF_F_PAD_ZEROS flag is set, memset the tail of @dst to 0 on success and
* memset all of @dst on failure.
*/
__bpf_kfunc int bpf_copy_from_user_str(void *dst, u32 dst__sz, const void __user *unsafe_ptr__ign, u64 flags)
{
int ret;
if (unlikely(flags & ~BPF_F_PAD_ZEROS))
return -EINVAL;
if (unlikely(!dst__sz))
return 0;
ret = strncpy_from_user(dst, unsafe_ptr__ign, dst__sz - 1);
if (ret < 0) {
if (flags & BPF_F_PAD_ZEROS)
memset((char *)dst, 0, dst__sz);
return ret;
}
if (flags & BPF_F_PAD_ZEROS)
memset((char *)dst + ret, 0, dst__sz - ret);
else
((char *)dst)[ret] = '\0';
return ret + 1;
}
__bpf_kfunc_end_defs();
BTF_KFUNCS_START(generic_btf_ids)
#ifdef CONFIG_CRASH_DUMP
BTF_ID_FLAGS(func, crash_kexec, KF_DESTRUCTIVE)
#endif
BTF_ID_FLAGS(func, bpf_obj_new_impl, KF_ACQUIRE | KF_RET_NULL)
BTF_ID_FLAGS(func, bpf_percpu_obj_new_impl, KF_ACQUIRE | KF_RET_NULL)
BTF_ID_FLAGS(func, bpf_obj_drop_impl, KF_RELEASE)
BTF_ID_FLAGS(func, bpf_percpu_obj_drop_impl, KF_RELEASE)
BTF_ID_FLAGS(func, bpf_refcount_acquire_impl, KF_ACQUIRE | KF_RET_NULL | KF_RCU)
BTF_ID_FLAGS(func, bpf_list_push_front_impl)
BTF_ID_FLAGS(func, bpf_list_push_back_impl)
BTF_ID_FLAGS(func, bpf_list_pop_front, KF_ACQUIRE | KF_RET_NULL)
BTF_ID_FLAGS(func, bpf_list_pop_back, KF_ACQUIRE | KF_RET_NULL)
BTF_ID_FLAGS(func, bpf_task_acquire, KF_ACQUIRE | KF_RCU | KF_RET_NULL)
BTF_ID_FLAGS(func, bpf_task_release, KF_RELEASE)
BTF_ID_FLAGS(func, bpf_rbtree_remove, KF_ACQUIRE | KF_RET_NULL)
BTF_ID_FLAGS(func, bpf_rbtree_add_impl)
BTF_ID_FLAGS(func, bpf_rbtree_first, KF_RET_NULL)
#ifdef CONFIG_CGROUPS
BTF_ID_FLAGS(func, bpf_cgroup_acquire, KF_ACQUIRE | KF_RCU | KF_RET_NULL)
BTF_ID_FLAGS(func, bpf_cgroup_release, KF_RELEASE)
BTF_ID_FLAGS(func, bpf_cgroup_ancestor, KF_ACQUIRE | KF_RCU | KF_RET_NULL)
BTF_ID_FLAGS(func, bpf_cgroup_from_id, KF_ACQUIRE | KF_RET_NULL)
BTF_ID_FLAGS(func, bpf_task_under_cgroup, KF_RCU)
BTF_ID_FLAGS(func, bpf_task_get_cgroup1, KF_ACQUIRE | KF_RCU | KF_RET_NULL)
#endif
BTF_ID_FLAGS(func, bpf_task_from_pid, KF_ACQUIRE | KF_RET_NULL)
BTF_ID_FLAGS(func, bpf_throw)
BTF_KFUNCS_END(generic_btf_ids)
static const struct btf_kfunc_id_set generic_kfunc_set = {
.owner = THIS_MODULE,
.set = &generic_btf_ids,
};
BTF_ID_LIST(generic_dtor_ids)
BTF_ID(struct, task_struct)
BTF_ID(func, bpf_task_release_dtor)
#ifdef CONFIG_CGROUPS
BTF_ID(struct, cgroup)
BTF_ID(func, bpf_cgroup_release_dtor)
#endif
BTF_KFUNCS_START(common_btf_ids)
BTF_ID_FLAGS(func, bpf_cast_to_kern_ctx)
BTF_ID_FLAGS(func, bpf_rdonly_cast)
BTF_ID_FLAGS(func, bpf_rcu_read_lock)
BTF_ID_FLAGS(func, bpf_rcu_read_unlock)
BTF_ID_FLAGS(func, bpf_dynptr_slice, KF_RET_NULL)
BTF_ID_FLAGS(func, bpf_dynptr_slice_rdwr, KF_RET_NULL)
BTF_ID_FLAGS(func, bpf_iter_num_new, KF_ITER_NEW)
BTF_ID_FLAGS(func, bpf_iter_num_next, KF_ITER_NEXT | KF_RET_NULL)
BTF_ID_FLAGS(func, bpf_iter_num_destroy, KF_ITER_DESTROY)
BTF_ID_FLAGS(func, bpf_iter_task_vma_new, KF_ITER_NEW | KF_RCU)
BTF_ID_FLAGS(func, bpf_iter_task_vma_next, KF_ITER_NEXT | KF_RET_NULL)
BTF_ID_FLAGS(func, bpf_iter_task_vma_destroy, KF_ITER_DESTROY)
#ifdef CONFIG_CGROUPS
BTF_ID_FLAGS(func, bpf_iter_css_task_new, KF_ITER_NEW | KF_TRUSTED_ARGS)
BTF_ID_FLAGS(func, bpf_iter_css_task_next, KF_ITER_NEXT | KF_RET_NULL)
BTF_ID_FLAGS(func, bpf_iter_css_task_destroy, KF_ITER_DESTROY)
BTF_ID_FLAGS(func, bpf_iter_css_new, KF_ITER_NEW | KF_TRUSTED_ARGS | KF_RCU_PROTECTED)
BTF_ID_FLAGS(func, bpf_iter_css_next, KF_ITER_NEXT | KF_RET_NULL)
BTF_ID_FLAGS(func, bpf_iter_css_destroy, KF_ITER_DESTROY)
#endif
BTF_ID_FLAGS(func, bpf_iter_task_new, KF_ITER_NEW | KF_TRUSTED_ARGS | KF_RCU_PROTECTED)
BTF_ID_FLAGS(func, bpf_iter_task_next, KF_ITER_NEXT | KF_RET_NULL)
BTF_ID_FLAGS(func, bpf_iter_task_destroy, KF_ITER_DESTROY)
BTF_ID_FLAGS(func, bpf_dynptr_adjust)
BTF_ID_FLAGS(func, bpf_dynptr_is_null)
BTF_ID_FLAGS(func, bpf_dynptr_is_rdonly)
BTF_ID_FLAGS(func, bpf_dynptr_size)
BTF_ID_FLAGS(func, bpf_dynptr_clone)
BTF_ID_FLAGS(func, bpf_modify_return_test_tp)
BTF_ID_FLAGS(func, bpf_wq_init)
BTF_ID_FLAGS(func, bpf_wq_set_callback_impl)
BTF_ID_FLAGS(func, bpf_wq_start)
BTF_ID_FLAGS(func, bpf_preempt_disable)
BTF_ID_FLAGS(func, bpf_preempt_enable)
BTF_ID_FLAGS(func, bpf_iter_bits_new, KF_ITER_NEW)
BTF_ID_FLAGS(func, bpf_iter_bits_next, KF_ITER_NEXT | KF_RET_NULL)
BTF_ID_FLAGS(func, bpf_iter_bits_destroy, KF_ITER_DESTROY)
BTF_ID_FLAGS(func, bpf_copy_from_user_str, KF_SLEEPABLE)
BTF_KFUNCS_END(common_btf_ids)
static const struct btf_kfunc_id_set common_kfunc_set = {
.owner = THIS_MODULE,
.set = &common_btf_ids,
};
static int __init kfunc_init(void)
{
int ret;
const struct btf_id_dtor_kfunc generic_dtors[] = {
{
.btf_id = generic_dtor_ids[0],
.kfunc_btf_id = generic_dtor_ids[1]
},
#ifdef CONFIG_CGROUPS
{
.btf_id = generic_dtor_ids[2],
.kfunc_btf_id = generic_dtor_ids[3]
},
#endif
};
ret = register_btf_kfunc_id_set(BPF_PROG_TYPE_TRACING, &generic_kfunc_set);
ret = ret ?: register_btf_kfunc_id_set(BPF_PROG_TYPE_SCHED_CLS, &generic_kfunc_set);
ret = ret ?: register_btf_kfunc_id_set(BPF_PROG_TYPE_XDP, &generic_kfunc_set);
ret = ret ?: register_btf_kfunc_id_set(BPF_PROG_TYPE_STRUCT_OPS, &generic_kfunc_set);
ret = ret ?: register_btf_kfunc_id_set(BPF_PROG_TYPE_SYSCALL, &generic_kfunc_set);
ret = ret ?: register_btf_kfunc_id_set(BPF_PROG_TYPE_CGROUP_SKB, &generic_kfunc_set);
ret = ret ?: register_btf_id_dtor_kfuncs(generic_dtors,
ARRAY_SIZE(generic_dtors),
THIS_MODULE);
return ret ?: register_btf_kfunc_id_set(BPF_PROG_TYPE_UNSPEC, &common_kfunc_set);
}
late_initcall(kfunc_init);
/* Get a pointer to dynptr data up to len bytes for read only access. If
* the dynptr doesn't have continuous data up to len bytes, return NULL.
*/
const void *__bpf_dynptr_data(const struct bpf_dynptr_kern *ptr, u32 len)
{
const struct bpf_dynptr *p = (struct bpf_dynptr *)ptr;
return bpf_dynptr_slice(p, 0, NULL, len);
}
/* Get a pointer to dynptr data up to len bytes for read write access. If
* the dynptr doesn't have continuous data up to len bytes, or the dynptr
* is read only, return NULL.
*/
void *__bpf_dynptr_data_rw(const struct bpf_dynptr_kern *ptr, u32 len)
{
if (__bpf_dynptr_is_rdonly(ptr))
return NULL;
return (void *)__bpf_dynptr_data(ptr, len);
}
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