mirror of
https://github.com/AuxXxilium/linux_dsm_epyc7002.git
synced 2024-12-27 12:25:08 +07:00
d0003ec01c
expose bpf_map_lookup_elem(), bpf_map_update_elem(), bpf_map_delete_elem() map accessors to eBPF programs Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Signed-off-by: David S. Miller <davem@davemloft.net>
90 lines
2.8 KiB
C
90 lines
2.8 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>
|
|
|
|
/* 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;
|
|
}
|
|
|
|
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);
|
|
}
|
|
|
|
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);
|
|
}
|
|
|
|
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,
|
|
};
|