forked from luck/tmp_suning_uos_patched
80b48c4457
Use smp_processor_id() for the generic helper bpf_get_smp_processor_id() instead of the raw variant. This allows for preemption checks when we have DEBUG_PREEMPT, and otherwise uses the raw variant anyway. We only need to keep the raw variant for socket filters, but we can reuse the helper that is already there from cBPF side. Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
189 lines
5.0 KiB
C
189 lines
5.0 KiB
C
/* Copyright (c) 2011-2014 PLUMgrid, http://plumgrid.com
|
|
*
|
|
* This program is free software; you can redistribute it and/or
|
|
* modify it under the terms of version 2 of the GNU General Public
|
|
* License as published by the Free Software Foundation.
|
|
*
|
|
* This program is distributed in the hope that it will be useful, but
|
|
* WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
|
|
* General Public License for more details.
|
|
*/
|
|
#include <linux/bpf.h>
|
|
#include <linux/rcupdate.h>
|
|
#include <linux/random.h>
|
|
#include <linux/smp.h>
|
|
#include <linux/ktime.h>
|
|
#include <linux/sched.h>
|
|
#include <linux/uidgid.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.
|
|
*/
|
|
static u64 bpf_map_lookup_elem(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5)
|
|
{
|
|
/* verifier checked that R1 contains a valid pointer to bpf_map
|
|
* and R2 points to a program stack and map->key_size bytes were
|
|
* initialized
|
|
*/
|
|
struct bpf_map *map = (struct bpf_map *) (unsigned long) r1;
|
|
void *key = (void *) (unsigned long) r2;
|
|
void *value;
|
|
|
|
WARN_ON_ONCE(!rcu_read_lock_held());
|
|
|
|
value = map->ops->map_lookup_elem(map, key);
|
|
|
|
/* lookup() returns either pointer to element value or NULL
|
|
* which is the meaning of PTR_TO_MAP_VALUE_OR_NULL type
|
|
*/
|
|
return (unsigned long) value;
|
|
}
|
|
|
|
const struct bpf_func_proto bpf_map_lookup_elem_proto = {
|
|
.func = bpf_map_lookup_elem,
|
|
.gpl_only = false,
|
|
.ret_type = RET_PTR_TO_MAP_VALUE_OR_NULL,
|
|
.arg1_type = ARG_CONST_MAP_PTR,
|
|
.arg2_type = ARG_PTR_TO_MAP_KEY,
|
|
};
|
|
|
|
static u64 bpf_map_update_elem(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5)
|
|
{
|
|
struct bpf_map *map = (struct bpf_map *) (unsigned long) r1;
|
|
void *key = (void *) (unsigned long) r2;
|
|
void *value = (void *) (unsigned long) r3;
|
|
|
|
WARN_ON_ONCE(!rcu_read_lock_held());
|
|
|
|
return map->ops->map_update_elem(map, key, value, r4);
|
|
}
|
|
|
|
const struct bpf_func_proto bpf_map_update_elem_proto = {
|
|
.func = bpf_map_update_elem,
|
|
.gpl_only = false,
|
|
.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,
|
|
};
|
|
|
|
static u64 bpf_map_delete_elem(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5)
|
|
{
|
|
struct bpf_map *map = (struct bpf_map *) (unsigned long) r1;
|
|
void *key = (void *) (unsigned long) r2;
|
|
|
|
WARN_ON_ONCE(!rcu_read_lock_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,
|
|
.ret_type = RET_INTEGER,
|
|
.arg1_type = ARG_CONST_MAP_PTR,
|
|
.arg2_type = ARG_PTR_TO_MAP_KEY,
|
|
};
|
|
|
|
const struct bpf_func_proto bpf_get_prandom_u32_proto = {
|
|
.func = bpf_user_rnd_u32,
|
|
.gpl_only = false,
|
|
.ret_type = RET_INTEGER,
|
|
};
|
|
|
|
static u64 bpf_get_smp_processor_id(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5)
|
|
{
|
|
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,
|
|
};
|
|
|
|
static u64 bpf_ktime_get_ns(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5)
|
|
{
|
|
/* 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 = true,
|
|
.ret_type = RET_INTEGER,
|
|
};
|
|
|
|
static u64 bpf_get_current_pid_tgid(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5)
|
|
{
|
|
struct task_struct *task = current;
|
|
|
|
if (!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,
|
|
};
|
|
|
|
static u64 bpf_get_current_uid_gid(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5)
|
|
{
|
|
struct task_struct *task = current;
|
|
kuid_t uid;
|
|
kgid_t gid;
|
|
|
|
if (!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,
|
|
};
|
|
|
|
static u64 bpf_get_current_comm(u64 r1, u64 size, u64 r3, u64 r4, u64 r5)
|
|
{
|
|
struct task_struct *task = current;
|
|
char *buf = (char *) (long) r1;
|
|
|
|
if (unlikely(!task))
|
|
goto err_clear;
|
|
|
|
strncpy(buf, task->comm, size);
|
|
|
|
/* Verifier guarantees that size > 0. For task->comm exceeding
|
|
* size, guarantee that buf is %NUL-terminated. Unconditionally
|
|
* done here to save the size test.
|
|
*/
|
|
buf[size - 1] = 0;
|
|
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_RAW_STACK,
|
|
.arg2_type = ARG_CONST_STACK_SIZE,
|
|
};
|