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authorAlexei Starovoitov <ast@plumgrid.com>2015-10-20 20:02:34 -0700
committerDavid S. Miller <davem@davemloft.net>2015-10-22 06:42:15 -0700
commita43eec304259a6c637f4014a6d4767159b6a3aa3 (patch)
treeaecaeb92ff5263f446b002793d89a2a211dc246b /kernel/bpf/arraymap.c
parentfa128e6a148a0a58355bd6814c6283515bbd028a (diff)
downloadlinux-sh-a43eec304259a6c637f4014a6d4767159b6a3aa3.tar.gz
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/arraymap.c')
-rw-r--r--kernel/bpf/arraymap.c2
1 files changed, 2 insertions, 0 deletions
diff --git a/kernel/bpf/arraymap.c b/kernel/bpf/arraymap.c
index f2d9e698c753..e3cfe46b074f 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);