mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2024-08-22 17:01:14 +00:00
![Dave Marchevsky](/assets/img/avatar_default.png)
Commit 9e7a4d9831
("bpf: Allow LSM programs to use bpf spin locks")
disabled bpf_spin_lock usage in sleepable progs, stating:
Sleepable LSM programs can be preempted which means that allowng spin
locks will need more work (disabling preemption and the verifier
ensuring that no sleepable helpers are called when a spin lock is
held).
This patch disables preemption before grabbing bpf_spin_lock. The second
requirement above "no sleepable helpers are called when a spin lock is
held" is implicitly enforced by current verifier logic due to helper
calls in spin_lock CS being disabled except for a few exceptions, none
of which sleep.
Due to above preemption changes, bpf_spin_lock CS can also be considered
a RCU CS, so verifier's in_rcu_cs check is modified to account for this.
Signed-off-by: Dave Marchevsky <davemarchevsky@fb.com>
Link: https://lore.kernel.org/r/20230821193311.3290257-7-davemarchevsky@fb.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2528 lines
66 KiB
C
2528 lines
66 KiB
C
// 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 "../../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 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_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_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_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,
|
|
};
|
|
|
|
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,
|
|
long *, res)
|
|
{
|
|
long long _res;
|
|
int err;
|
|
|
|
err = __bpf_strtoll(buf, buf_len, flags, &_res);
|
|
if (err < 0)
|
|
return err;
|
|
if (_res != (long)_res)
|
|
return -ERANGE;
|
|
*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_LONG,
|
|
};
|
|
|
|
BPF_CALL_4(bpf_strtoul, const char *, buf, size_t, buf_len, u64, flags,
|
|
unsigned 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)
|
|
return -EINVAL;
|
|
if (_res != (unsigned long)_res)
|
|
return -ERANGE;
|
|
*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_LONG,
|
|
};
|
|
|
|
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 *)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 *)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,
|
|
};
|
|
|
|
/* 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_timer_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 hrtimer timer;
|
|
struct bpf_map *map;
|
|
struct bpf_prog *prog;
|
|
void __rcu *callback_fn;
|
|
void *value;
|
|
};
|
|
|
|
/* the actual struct hidden inside uapi struct bpf_timer */
|
|
struct bpf_timer_kern {
|
|
struct bpf_hrtimer *timer;
|
|
/* 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)));
|
|
|
|
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->map;
|
|
void *value = t->value;
|
|
bpf_callback_t callback_fn;
|
|
void *key;
|
|
u32 idx;
|
|
|
|
BTF_TYPE_EMIT(struct bpf_timer);
|
|
callback_fn = rcu_dereference_check(t->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;
|
|
}
|
|
|
|
BPF_CALL_3(bpf_timer_init, struct bpf_timer_kern *, timer, struct bpf_map *, map,
|
|
u64, flags)
|
|
{
|
|
clockid_t clockid = flags & (MAX_CLOCKS - 1);
|
|
struct bpf_hrtimer *t;
|
|
int ret = 0;
|
|
|
|
BUILD_BUG_ON(MAX_CLOCKS != 16);
|
|
BUILD_BUG_ON(sizeof(struct bpf_timer_kern) > sizeof(struct bpf_timer));
|
|
BUILD_BUG_ON(__alignof__(struct bpf_timer_kern) != __alignof__(struct bpf_timer));
|
|
|
|
if (in_nmi())
|
|
return -EOPNOTSUPP;
|
|
|
|
if (flags >= MAX_CLOCKS ||
|
|
/* similar to timerfd except _ALARM variants are not supported */
|
|
(clockid != CLOCK_MONOTONIC &&
|
|
clockid != CLOCK_REALTIME &&
|
|
clockid != CLOCK_BOOTTIME))
|
|
return -EINVAL;
|
|
__bpf_spin_lock_irqsave(&timer->lock);
|
|
t = timer->timer;
|
|
if (t) {
|
|
ret = -EBUSY;
|
|
goto out;
|
|
}
|
|
if (!atomic64_read(&map->usercnt)) {
|
|
/* maps with timers must be either held by user space
|
|
* or pinned in bpffs.
|
|
*/
|
|
ret = -EPERM;
|
|
goto out;
|
|
}
|
|
/* allocate hrtimer via map_kmalloc to use memcg accounting */
|
|
t = bpf_map_kmalloc_node(map, sizeof(*t), GFP_ATOMIC, map->numa_node);
|
|
if (!t) {
|
|
ret = -ENOMEM;
|
|
goto out;
|
|
}
|
|
t->value = (void *)timer - map->record->timer_off;
|
|
t->map = map;
|
|
t->prog = NULL;
|
|
rcu_assign_pointer(t->callback_fn, NULL);
|
|
hrtimer_init(&t->timer, clockid, HRTIMER_MODE_REL_SOFT);
|
|
t->timer.function = bpf_timer_cb;
|
|
timer->timer = t;
|
|
out:
|
|
__bpf_spin_unlock_irqrestore(&timer->lock);
|
|
return ret;
|
|
}
|
|
|
|
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,
|
|
};
|
|
|
|
BPF_CALL_3(bpf_timer_set_callback, struct bpf_timer_kern *, timer, void *, callback_fn,
|
|
struct bpf_prog_aux *, aux)
|
|
{
|
|
struct bpf_prog *prev, *prog = aux->prog;
|
|
struct bpf_hrtimer *t;
|
|
int ret = 0;
|
|
|
|
if (in_nmi())
|
|
return -EOPNOTSUPP;
|
|
__bpf_spin_lock_irqsave(&timer->lock);
|
|
t = timer->timer;
|
|
if (!t) {
|
|
ret = -EINVAL;
|
|
goto out;
|
|
}
|
|
if (!atomic64_read(&t->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 = t->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);
|
|
t->prog = prog;
|
|
}
|
|
rcu_assign_pointer(t->callback_fn, callback_fn);
|
|
out:
|
|
__bpf_spin_unlock_irqrestore(&timer->lock);
|
|
return ret;
|
|
}
|
|
|
|
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_timer_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)
|
|
return -EINVAL;
|
|
__bpf_spin_lock_irqsave(&timer->lock);
|
|
t = timer->timer;
|
|
if (!t || !t->prog) {
|
|
ret = -EINVAL;
|
|
goto out;
|
|
}
|
|
|
|
if (flags & BPF_F_TIMER_ABS)
|
|
mode = HRTIMER_MODE_ABS_SOFT;
|
|
else
|
|
mode = HRTIMER_MODE_REL_SOFT;
|
|
|
|
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_hrtimer *t)
|
|
{
|
|
struct bpf_prog *prog = t->prog;
|
|
|
|
if (prog) {
|
|
bpf_prog_put(prog);
|
|
t->prog = NULL;
|
|
rcu_assign_pointer(t->callback_fn, NULL);
|
|
}
|
|
}
|
|
|
|
BPF_CALL_1(bpf_timer_cancel, struct bpf_timer_kern *, timer)
|
|
{
|
|
struct bpf_hrtimer *t;
|
|
int ret = 0;
|
|
|
|
if (in_nmi())
|
|
return -EOPNOTSUPP;
|
|
__bpf_spin_lock_irqsave(&timer->lock);
|
|
t = timer->timer;
|
|
if (!t) {
|
|
ret = -EINVAL;
|
|
goto out;
|
|
}
|
|
if (this_cpu_read(hrtimer_running) == 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;
|
|
}
|
|
drop_prog_refcnt(t);
|
|
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);
|
|
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,
|
|
};
|
|
|
|
/* 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_timer_kern *timer = val;
|
|
struct bpf_hrtimer *t;
|
|
|
|
/* Performance optimization: read timer->timer without lock first. */
|
|
if (!READ_ONCE(timer->timer))
|
|
return;
|
|
|
|
__bpf_spin_lock_irqsave(&timer->lock);
|
|
/* re-read it under lock */
|
|
t = timer->timer;
|
|
if (!t)
|
|
goto out;
|
|
drop_prog_refcnt(t);
|
|
/* The subsequent bpf_timer_start/cancel() helpers won't be able to use
|
|
* this timer, since it won't be initialized.
|
|
*/
|
|
timer->timer = NULL;
|
|
out:
|
|
__bpf_spin_unlock_irqrestore(&timer->lock);
|
|
if (!t)
|
|
return;
|
|
/* 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(t)
|
|
* right after for both preallocated and non-preallocated maps.
|
|
* The timer->timer = NULL was already done and no code path can
|
|
* see address 't' anymore.
|
|
*
|
|
* Check that bpf_map_delete/update_elem() wasn't called from timer
|
|
* callback_fn. In such case 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 timer->timer = NULL was already done. The timer will be
|
|
* effectively cancelled because bpf_timer_cb() will return
|
|
* HRTIMER_NORESTART.
|
|
*/
|
|
if (this_cpu_read(hrtimer_running) != t)
|
|
hrtimer_cancel(&t->timer);
|
|
kfree(t);
|
|
}
|
|
|
|
BPF_CALL_2(bpf_kptr_xchg, void *, map_value, void *, ptr)
|
|
{
|
|
unsigned long *kptr = map_value;
|
|
|
|
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_PTR_TO_KPTR,
|
|
.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)
|
|
|
|
static 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)
|
|
{
|
|
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;
|
|
default:
|
|
break;
|
|
}
|
|
|
|
if (!bpf_capable())
|
|
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 (!perfmon_capable())
|
|
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;
|
|
}
|
|
}
|
|
|
|
void __bpf_obj_drop_impl(void *p, const struct btf_record *rec);
|
|
|
|
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);
|
|
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);
|
|
migrate_enable();
|
|
}
|
|
}
|
|
|
|
__diag_push();
|
|
__diag_ignore_all("-Wmissing-prototypes",
|
|
"Global functions as their definitions will be in vmlinux BTF");
|
|
|
|
__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;
|
|
}
|
|
|
|
/* Must be called under migrate_disable(), as required by bpf_mem_free */
|
|
void __bpf_obj_drop_impl(void *p, const struct btf_record *rec)
|
|
{
|
|
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 (rec && rec->refcount_off >= 0)
|
|
bpf_mem_free_rcu(&bpf_global_ma, p);
|
|
else
|
|
bpf_mem_free(&bpf_global_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);
|
|
}
|
|
|
|
__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);
|
|
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);
|
|
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);
|
|
}
|
|
|
|
#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_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)
|
|
{
|
|
return task_under_cgroup_hierarchy(task, ancestor);
|
|
}
|
|
#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.
|
|
* @ptr: 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_kern *ptr, u32 offset,
|
|
void *buffer__opt, u32 buffer__szk)
|
|
{
|
|
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.
|
|
* @ptr: 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_kern *ptr, u32 offset,
|
|
void *buffer__opt, u32 buffer__szk)
|
|
{
|
|
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 possiblities
|
|
* 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(ptr, offset, buffer__opt, buffer__szk);
|
|
}
|
|
|
|
__bpf_kfunc int bpf_dynptr_adjust(struct bpf_dynptr_kern *ptr, u32 start, u32 end)
|
|
{
|
|
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(struct bpf_dynptr_kern *ptr)
|
|
{
|
|
return !ptr->data;
|
|
}
|
|
|
|
__bpf_kfunc bool bpf_dynptr_is_rdonly(struct bpf_dynptr_kern *ptr)
|
|
{
|
|
if (!ptr->data)
|
|
return false;
|
|
|
|
return __bpf_dynptr_is_rdonly(ptr);
|
|
}
|
|
|
|
__bpf_kfunc __u32 bpf_dynptr_size(const struct bpf_dynptr_kern *ptr)
|
|
{
|
|
if (!ptr->data)
|
|
return -EINVAL;
|
|
|
|
return __bpf_dynptr_size(ptr);
|
|
}
|
|
|
|
__bpf_kfunc int bpf_dynptr_clone(struct bpf_dynptr_kern *ptr,
|
|
struct bpf_dynptr_kern *clone__uninit)
|
|
{
|
|
if (!ptr->data) {
|
|
bpf_dynptr_set_null(clone__uninit);
|
|
return -EINVAL;
|
|
}
|
|
|
|
*clone__uninit = *ptr;
|
|
|
|
return 0;
|
|
}
|
|
|
|
__bpf_kfunc void *bpf_cast_to_kern_ctx(void *obj)
|
|
{
|
|
return obj;
|
|
}
|
|
|
|
__bpf_kfunc void *bpf_rdonly_cast(void *obj__ign, u32 btf_id__k)
|
|
{
|
|
return obj__ign;
|
|
}
|
|
|
|
__bpf_kfunc void bpf_rcu_read_lock(void)
|
|
{
|
|
rcu_read_lock();
|
|
}
|
|
|
|
__bpf_kfunc void bpf_rcu_read_unlock(void)
|
|
{
|
|
rcu_read_unlock();
|
|
}
|
|
|
|
__diag_pop();
|
|
|
|
BTF_SET8_START(generic_btf_ids)
|
|
#ifdef CONFIG_KEXEC_CORE
|
|
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_obj_drop_impl, KF_RELEASE)
|
|
BTF_ID_FLAGS(func, bpf_refcount_acquire_impl, KF_ACQUIRE | KF_RET_NULL)
|
|
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)
|
|
#endif
|
|
BTF_ID_FLAGS(func, bpf_task_from_pid, KF_ACQUIRE | KF_RET_NULL)
|
|
BTF_SET8_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)
|
|
#ifdef CONFIG_CGROUPS
|
|
BTF_ID(struct, cgroup)
|
|
BTF_ID(func, bpf_cgroup_release)
|
|
#endif
|
|
|
|
BTF_SET8_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_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_SET8_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_STRUCT_OPS, &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);
|