mirror of
https://github.com/AuxXxilium/linux_dsm_epyc7002.git
synced 2024-12-16 03:06:58 +07:00
62544ce8e0
Fix safety checks for bpf_perf_event_read():
- only non-inherited events can be added to perf_event_array map
(do this check statically at map insertion time)
- dynamically check that event is local and !pmu->count
Otherwise buggy bpf program can cause kernel splat.
Also fix error path after perf_event_attrs()
and remove redundant 'extern'.
Fixes: 35578d7984
("bpf: Implement function bpf_perf_event_read() that get the selected hardware PMU conuter")
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Tested-by: Wang Nan <wangnan0@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
343 lines
8.5 KiB
C
343 lines
8.5 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/err.h>
|
|
#include <linux/vmalloc.h>
|
|
#include <linux/slab.h>
|
|
#include <linux/mm.h>
|
|
#include <linux/filter.h>
|
|
#include <linux/perf_event.h>
|
|
|
|
/* Called from syscall */
|
|
static struct bpf_map *array_map_alloc(union bpf_attr *attr)
|
|
{
|
|
struct bpf_array *array;
|
|
u32 elem_size, array_size;
|
|
|
|
/* check sanity of attributes */
|
|
if (attr->max_entries == 0 || attr->key_size != 4 ||
|
|
attr->value_size == 0)
|
|
return ERR_PTR(-EINVAL);
|
|
|
|
elem_size = round_up(attr->value_size, 8);
|
|
|
|
/* check round_up into zero and u32 overflow */
|
|
if (elem_size == 0 ||
|
|
attr->max_entries > (U32_MAX - sizeof(*array)) / elem_size)
|
|
return ERR_PTR(-ENOMEM);
|
|
|
|
array_size = sizeof(*array) + attr->max_entries * elem_size;
|
|
|
|
/* allocate all map elements and zero-initialize them */
|
|
array = kzalloc(array_size, GFP_USER | __GFP_NOWARN);
|
|
if (!array) {
|
|
array = vzalloc(array_size);
|
|
if (!array)
|
|
return ERR_PTR(-ENOMEM);
|
|
}
|
|
|
|
/* copy mandatory map attributes */
|
|
array->map.key_size = attr->key_size;
|
|
array->map.value_size = attr->value_size;
|
|
array->map.max_entries = attr->max_entries;
|
|
array->map.pages = round_up(array_size, PAGE_SIZE) >> PAGE_SHIFT;
|
|
array->elem_size = elem_size;
|
|
|
|
return &array->map;
|
|
}
|
|
|
|
/* Called from syscall or from eBPF program */
|
|
static void *array_map_lookup_elem(struct bpf_map *map, void *key)
|
|
{
|
|
struct bpf_array *array = container_of(map, struct bpf_array, map);
|
|
u32 index = *(u32 *)key;
|
|
|
|
if (index >= array->map.max_entries)
|
|
return NULL;
|
|
|
|
return array->value + array->elem_size * index;
|
|
}
|
|
|
|
/* Called from syscall */
|
|
static int array_map_get_next_key(struct bpf_map *map, void *key, void *next_key)
|
|
{
|
|
struct bpf_array *array = container_of(map, struct bpf_array, map);
|
|
u32 index = *(u32 *)key;
|
|
u32 *next = (u32 *)next_key;
|
|
|
|
if (index >= array->map.max_entries) {
|
|
*next = 0;
|
|
return 0;
|
|
}
|
|
|
|
if (index == array->map.max_entries - 1)
|
|
return -ENOENT;
|
|
|
|
*next = index + 1;
|
|
return 0;
|
|
}
|
|
|
|
/* Called from syscall or from eBPF program */
|
|
static int array_map_update_elem(struct bpf_map *map, void *key, void *value,
|
|
u64 map_flags)
|
|
{
|
|
struct bpf_array *array = container_of(map, struct bpf_array, map);
|
|
u32 index = *(u32 *)key;
|
|
|
|
if (map_flags > BPF_EXIST)
|
|
/* unknown flags */
|
|
return -EINVAL;
|
|
|
|
if (index >= array->map.max_entries)
|
|
/* all elements were pre-allocated, cannot insert a new one */
|
|
return -E2BIG;
|
|
|
|
if (map_flags == BPF_NOEXIST)
|
|
/* all elements already exist */
|
|
return -EEXIST;
|
|
|
|
memcpy(array->value + array->elem_size * index, value, array->elem_size);
|
|
return 0;
|
|
}
|
|
|
|
/* Called from syscall or from eBPF program */
|
|
static int array_map_delete_elem(struct bpf_map *map, void *key)
|
|
{
|
|
return -EINVAL;
|
|
}
|
|
|
|
/* Called when map->refcnt goes to zero, either from workqueue or from syscall */
|
|
static void array_map_free(struct bpf_map *map)
|
|
{
|
|
struct bpf_array *array = container_of(map, struct bpf_array, map);
|
|
|
|
/* at this point bpf_prog->aux->refcnt == 0 and this map->refcnt == 0,
|
|
* so the programs (can be more than one that used this map) were
|
|
* disconnected from events. Wait for outstanding programs to complete
|
|
* and free the array
|
|
*/
|
|
synchronize_rcu();
|
|
|
|
kvfree(array);
|
|
}
|
|
|
|
static const struct bpf_map_ops array_ops = {
|
|
.map_alloc = array_map_alloc,
|
|
.map_free = array_map_free,
|
|
.map_get_next_key = array_map_get_next_key,
|
|
.map_lookup_elem = array_map_lookup_elem,
|
|
.map_update_elem = array_map_update_elem,
|
|
.map_delete_elem = array_map_delete_elem,
|
|
};
|
|
|
|
static struct bpf_map_type_list array_type __read_mostly = {
|
|
.ops = &array_ops,
|
|
.type = BPF_MAP_TYPE_ARRAY,
|
|
};
|
|
|
|
static int __init register_array_map(void)
|
|
{
|
|
bpf_register_map_type(&array_type);
|
|
return 0;
|
|
}
|
|
late_initcall(register_array_map);
|
|
|
|
static struct bpf_map *fd_array_map_alloc(union bpf_attr *attr)
|
|
{
|
|
/* only file descriptors can be stored in this type of map */
|
|
if (attr->value_size != sizeof(u32))
|
|
return ERR_PTR(-EINVAL);
|
|
return array_map_alloc(attr);
|
|
}
|
|
|
|
static void fd_array_map_free(struct bpf_map *map)
|
|
{
|
|
struct bpf_array *array = container_of(map, struct bpf_array, map);
|
|
int i;
|
|
|
|
synchronize_rcu();
|
|
|
|
/* make sure it's empty */
|
|
for (i = 0; i < array->map.max_entries; i++)
|
|
BUG_ON(array->ptrs[i] != NULL);
|
|
kvfree(array);
|
|
}
|
|
|
|
static void *fd_array_map_lookup_elem(struct bpf_map *map, void *key)
|
|
{
|
|
return NULL;
|
|
}
|
|
|
|
/* only called from syscall */
|
|
static int fd_array_map_update_elem(struct bpf_map *map, void *key,
|
|
void *value, u64 map_flags)
|
|
{
|
|
struct bpf_array *array = container_of(map, struct bpf_array, map);
|
|
void *new_ptr, *old_ptr;
|
|
u32 index = *(u32 *)key, ufd;
|
|
|
|
if (map_flags != BPF_ANY)
|
|
return -EINVAL;
|
|
|
|
if (index >= array->map.max_entries)
|
|
return -E2BIG;
|
|
|
|
ufd = *(u32 *)value;
|
|
new_ptr = map->ops->map_fd_get_ptr(map, ufd);
|
|
if (IS_ERR(new_ptr))
|
|
return PTR_ERR(new_ptr);
|
|
|
|
old_ptr = xchg(array->ptrs + index, new_ptr);
|
|
if (old_ptr)
|
|
map->ops->map_fd_put_ptr(old_ptr);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int fd_array_map_delete_elem(struct bpf_map *map, void *key)
|
|
{
|
|
struct bpf_array *array = container_of(map, struct bpf_array, map);
|
|
void *old_ptr;
|
|
u32 index = *(u32 *)key;
|
|
|
|
if (index >= array->map.max_entries)
|
|
return -E2BIG;
|
|
|
|
old_ptr = xchg(array->ptrs + index, NULL);
|
|
if (old_ptr) {
|
|
map->ops->map_fd_put_ptr(old_ptr);
|
|
return 0;
|
|
} else {
|
|
return -ENOENT;
|
|
}
|
|
}
|
|
|
|
static void *prog_fd_array_get_ptr(struct bpf_map *map, int fd)
|
|
{
|
|
struct bpf_array *array = container_of(map, struct bpf_array, map);
|
|
struct bpf_prog *prog = bpf_prog_get(fd);
|
|
if (IS_ERR(prog))
|
|
return prog;
|
|
|
|
if (!bpf_prog_array_compatible(array, prog)) {
|
|
bpf_prog_put(prog);
|
|
return ERR_PTR(-EINVAL);
|
|
}
|
|
return prog;
|
|
}
|
|
|
|
static void prog_fd_array_put_ptr(void *ptr)
|
|
{
|
|
struct bpf_prog *prog = ptr;
|
|
|
|
bpf_prog_put_rcu(prog);
|
|
}
|
|
|
|
/* decrement refcnt of all bpf_progs that are stored in this map */
|
|
void bpf_fd_array_map_clear(struct bpf_map *map)
|
|
{
|
|
struct bpf_array *array = container_of(map, struct bpf_array, map);
|
|
int i;
|
|
|
|
for (i = 0; i < array->map.max_entries; i++)
|
|
fd_array_map_delete_elem(map, &i);
|
|
}
|
|
|
|
static const struct bpf_map_ops prog_array_ops = {
|
|
.map_alloc = fd_array_map_alloc,
|
|
.map_free = fd_array_map_free,
|
|
.map_get_next_key = array_map_get_next_key,
|
|
.map_lookup_elem = fd_array_map_lookup_elem,
|
|
.map_update_elem = fd_array_map_update_elem,
|
|
.map_delete_elem = fd_array_map_delete_elem,
|
|
.map_fd_get_ptr = prog_fd_array_get_ptr,
|
|
.map_fd_put_ptr = prog_fd_array_put_ptr,
|
|
};
|
|
|
|
static struct bpf_map_type_list prog_array_type __read_mostly = {
|
|
.ops = &prog_array_ops,
|
|
.type = BPF_MAP_TYPE_PROG_ARRAY,
|
|
};
|
|
|
|
static int __init register_prog_array_map(void)
|
|
{
|
|
bpf_register_map_type(&prog_array_type);
|
|
return 0;
|
|
}
|
|
late_initcall(register_prog_array_map);
|
|
|
|
static void perf_event_array_map_free(struct bpf_map *map)
|
|
{
|
|
bpf_fd_array_map_clear(map);
|
|
fd_array_map_free(map);
|
|
}
|
|
|
|
static void *perf_event_fd_array_get_ptr(struct bpf_map *map, int fd)
|
|
{
|
|
struct perf_event *event;
|
|
const struct perf_event_attr *attr;
|
|
|
|
event = perf_event_get(fd);
|
|
if (IS_ERR(event))
|
|
return event;
|
|
|
|
attr = perf_event_attrs(event);
|
|
if (IS_ERR(attr))
|
|
goto err;
|
|
|
|
if (attr->inherit)
|
|
goto err;
|
|
|
|
if (attr->type == PERF_TYPE_RAW)
|
|
return event;
|
|
|
|
if (attr->type == PERF_TYPE_HARDWARE)
|
|
return event;
|
|
|
|
if (attr->type == PERF_TYPE_SOFTWARE &&
|
|
attr->config == PERF_COUNT_SW_BPF_OUTPUT)
|
|
return event;
|
|
err:
|
|
perf_event_release_kernel(event);
|
|
return ERR_PTR(-EINVAL);
|
|
}
|
|
|
|
static void perf_event_fd_array_put_ptr(void *ptr)
|
|
{
|
|
struct perf_event *event = ptr;
|
|
|
|
perf_event_release_kernel(event);
|
|
}
|
|
|
|
static const struct bpf_map_ops perf_event_array_ops = {
|
|
.map_alloc = fd_array_map_alloc,
|
|
.map_free = perf_event_array_map_free,
|
|
.map_get_next_key = array_map_get_next_key,
|
|
.map_lookup_elem = fd_array_map_lookup_elem,
|
|
.map_update_elem = fd_array_map_update_elem,
|
|
.map_delete_elem = fd_array_map_delete_elem,
|
|
.map_fd_get_ptr = perf_event_fd_array_get_ptr,
|
|
.map_fd_put_ptr = perf_event_fd_array_put_ptr,
|
|
};
|
|
|
|
static struct bpf_map_type_list perf_event_array_type __read_mostly = {
|
|
.ops = &perf_event_array_ops,
|
|
.type = BPF_MAP_TYPE_PERF_EVENT_ARRAY,
|
|
};
|
|
|
|
static int __init register_perf_event_array_map(void)
|
|
{
|
|
bpf_register_map_type(&perf_event_array_type);
|
|
return 0;
|
|
}
|
|
late_initcall(register_perf_event_array_map);
|