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authorKaixu Xia <xiakaixu@huawei.com>2015-08-06 07:02:34 +0000
committerDavid S. Miller <davem@davemloft.net>2015-08-09 22:50:05 -0700
commitea317b267e9d03a8241893aa176fba7661d07579 (patch)
tree75d0e648c42e56ae0f2ae0f5e33226ce4bb77fee
parent2a36f0b92eb638dd023870574eb471b1c56be9ad (diff)
downloadlinux-sh-ea317b267e9d03a8241893aa176fba7661d07579.tar.gz
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: Kaixu Xia <xiakaixu@huawei.com> Signed-off-by: David S. Miller <davem@davemloft.net>
-rw-r--r--include/linux/bpf.h1
-rw-r--r--include/uapi/linux/bpf.h1
-rw-r--r--kernel/bpf/arraymap.c57
3 files changed, 59 insertions, 0 deletions
diff --git a/include/linux/bpf.h b/include/linux/bpf.h
index d495211d63d1..4fc1f4070789 100644
--- a/include/linux/bpf.h
+++ b/include/linux/bpf.h
@@ -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;
diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h
index 2ce13c109b00..a1814e8e53a7 100644
--- a/include/uapi/linux/bpf.h
+++ b/include/uapi/linux/bpf.h
@@ -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 {
diff --git a/kernel/bpf/arraymap.c b/kernel/bpf/arraymap.c
index 45df6572ecfd..29ace107f236 100644
--- a/kernel/bpf/arraymap.c
+++ b/kernel/bpf/arraymap.c
@@ -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);