diff options
| author | Alexei Starovoitov <ast@plumgrid.com> | 2015-10-21 03:02:34 (GMT) |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2015-10-22 13:42:15 (GMT) |
| commit | a43eec304259a6c637f4014a6d4767159b6a3aa3 (patch) | |
| tree | aecaeb92ff5263f446b002793d89a2a211dc246b /kernel/bpf | |
| parent | fa128e6a148a0a58355bd6814c6283515bbd028a (diff) | |
| download | linux-a43eec304259a6c637f4014a6d4767159b6a3aa3.tar.xz | |
bpf: introduce bpf_perf_event_output() helper
This helper is used to send raw data from eBPF program into
special PERF_TYPE_SOFTWARE/PERF_COUNT_SW_BPF_OUTPUT perf_event.
User space needs to perf_event_open() it (either for one or all cpus) and
store FD into perf_event_array (similar to bpf_perf_event_read() helper)
before eBPF program can send data into it.
Today the programs triggered by kprobe collect the data and either store
it into the maps or print it via bpf_trace_printk() where latter is the debug
facility and not suitable to stream the data. This new helper replaces
such bpf_trace_printk() usage and allows programs to have dedicated
channel into user space for post-processing of the raw data collected.
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'kernel/bpf')
| -rw-r--r-- | kernel/bpf/arraymap.c | 2 | ||||
| -rw-r--r-- | kernel/bpf/verifier.c | 3 |
2 files changed, 4 insertions, 1 deletions
diff --git a/kernel/bpf/arraymap.c b/kernel/bpf/arraymap.c index f2d9e69..e3cfe46 100644 --- a/kernel/bpf/arraymap.c +++ b/kernel/bpf/arraymap.c @@ -295,6 +295,8 @@ static void *perf_event_fd_array_get_ptr(struct bpf_map *map, int fd) return (void *)attr; if (attr->type != PERF_TYPE_RAW && + !(attr->type == PERF_TYPE_SOFTWARE && + attr->config == PERF_COUNT_SW_BPF_OUTPUT) && attr->type != PERF_TYPE_HARDWARE) { perf_event_release_kernel(event); return ERR_PTR(-EINVAL); diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c index 1d6b97b..b56cf51 100644 --- a/kernel/bpf/verifier.c +++ b/kernel/bpf/verifier.c @@ -245,6 +245,7 @@ static const struct { } func_limit[] = { {BPF_MAP_TYPE_PROG_ARRAY, BPF_FUNC_tail_call}, {BPF_MAP_TYPE_PERF_EVENT_ARRAY, BPF_FUNC_perf_event_read}, + {BPF_MAP_TYPE_PERF_EVENT_ARRAY, BPF_FUNC_perf_event_output}, }; static void print_verifier_state(struct verifier_env *env) @@ -910,7 +911,7 @@ static int check_map_func_compatibility(struct bpf_map *map, int func_id) * don't allow any other map type to be passed into * the special func; */ - if (bool_map != bool_func) + if (bool_func && bool_map != bool_func) return -EINVAL; } |