Commit ea317b26 authored by Kaixu Xia's avatar Kaixu Xia Committed by David S. Miller
Browse files

bpf: Add new bpf map type to store the pointer to struct perf_event



Introduce a new bpf map type 'BPF_MAP_TYPE_PERF_EVENT_ARRAY'.
This map only stores the pointer to struct perf_event. The
user space event FDs from perf_event_open() syscall are converted
to the pointer to struct perf_event and stored in map.

Signed-off-by: default avatarKaixu Xia <xiakaixu@huawei.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 2a36f0b9
......@@ -10,6 +10,7 @@
#include <uapi/linux/bpf.h>
#include <linux/workqueue.h>
#include <linux/file.h>
#include <linux/perf_event.h>
struct bpf_map;
......
......@@ -114,6 +114,7 @@ enum bpf_map_type {
BPF_MAP_TYPE_HASH,
BPF_MAP_TYPE_ARRAY,
BPF_MAP_TYPE_PROG_ARRAY,
BPF_MAP_TYPE_PERF_EVENT_ARRAY,
};
enum bpf_prog_type {
......
......@@ -273,3 +273,60 @@ static int __init register_prog_array_map(void)
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))
return (void *)attr;
if (attr->type != PERF_TYPE_RAW &&
attr->type != PERF_TYPE_HARDWARE) {
perf_event_release_kernel(event);
return ERR_PTR(-EINVAL);
}
return event;
}
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);
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