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author | Kaixu Xia <xiakaixu@huawei.com> | 2015-08-06 07:02:34 +0000 |
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committer | David S. Miller <davem@davemloft.net> | 2015-08-09 22:50:05 -0700 |
commit | ea317b267e9d03a8241893aa176fba7661d07579 (patch) | |
tree | 75d0e648c42e56ae0f2ae0f5e33226ce4bb77fee /kernel/bpf/arraymap.c | |
parent | 2a36f0b92eb638dd023870574eb471b1c56be9ad (diff) | |
download | linux-ea317b267e9d03a8241893aa176fba7661d07579.tar.gz linux-ea317b267e9d03a8241893aa176fba7661d07579.tar.bz2 linux-ea317b267e9d03a8241893aa176fba7661d07579.zip |
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>
Diffstat (limited to 'kernel/bpf/arraymap.c')
-rw-r--r-- | kernel/bpf/arraymap.c | 57 |
1 files changed, 57 insertions, 0 deletions
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); |