[PATCH v2 net-next 1/3] perf, bpf: Add BPF support to all perf_event types

[Alexei Starovoitov]

From: Teng Qin <qint...@fb.com>

Allow BPF program to attach to all perf_event types supported
by the current bpf and perf code logic, including HW_CACHE, RAW,
and dynamic pmu events.

Also add support for reading these event counters using
bpf_perf_event_read() helper.

Signed-off-by: Teng Qin <qint...@fb.com>
Signed-off-by: Alexei Starovoitov <a...@kernel.org>
---
 kernel/bpf/arraymap.c    | 26 +++++++++++---------------
 kernel/events/core.c     |  6 +-----
 kernel/trace/bpf_trace.c |  4 ++--
 3 files changed, 14 insertions(+), 22 deletions(-)

diff --git a/kernel/bpf/arraymap.c b/kernel/bpf/arraymap.c
index 5e00b2333c26..55ffa9949128 100644
--- a/kernel/bpf/arraymap.c
+++ b/kernel/bpf/arraymap.c
@@ -462,26 +462,22 @@ static void *perf_event_fd_array_get_ptr(struct bpf_map 
*map,
 
        event = perf_file->private_data;
        ee = ERR_PTR(-EINVAL);
+       /* Per-task events are not supported */
+       if (event->attach_state & PERF_ATTACH_TASK)
+               goto err_out;
 
        attr = perf_event_attrs(event);
        if (IS_ERR(attr) || attr->inherit)
                goto err_out;
+       /* TRACEPOINT and BREAKPOINT not supported in perf_event_read_local */
+       if (attr->type == PERF_TYPE_TRACEPOINT ||
+           attr->type == PERF_TYPE_BREAKPOINT)
+               goto err_out;
 
-       switch (attr->type) {
-       case PERF_TYPE_SOFTWARE:
-               if (attr->config != PERF_COUNT_SW_BPF_OUTPUT)
-                       goto err_out;
-               /* fall-through */
-       case PERF_TYPE_RAW:
-       case PERF_TYPE_HARDWARE:
-               ee = bpf_event_entry_gen(perf_file, map_file);
-               if (ee)
-                       return ee;
-               ee = ERR_PTR(-ENOMEM);
-               /* fall-through */
-       default:
-               break;
-       }
+       ee = bpf_event_entry_gen(perf_file, map_file);
+       if (ee)
+               return ee;
+       ee = ERR_PTR(-ENOMEM);
 
 err_out:
        fput(perf_file);
diff --git a/kernel/events/core.c b/kernel/events/core.c
index 6e75a5c9412d..52f667046599 100644
--- a/kernel/events/core.c
+++ b/kernel/events/core.c
@@ -8037,12 +8037,8 @@ static int perf_event_set_bpf_prog(struct perf_event 
*event, u32 prog_fd)
        bool is_kprobe, is_tracepoint;
        struct bpf_prog *prog;
 
-       if (event->attr.type == PERF_TYPE_HARDWARE ||
-           event->attr.type == PERF_TYPE_SOFTWARE)
-               return perf_event_set_bpf_handler(event, prog_fd);
-
        if (event->attr.type != PERF_TYPE_TRACEPOINT)
-               return -EINVAL;
+               return perf_event_set_bpf_handler(event, prog_fd);
 
        if (event->tp_event->prog)
                return -EEXIST;
diff --git a/kernel/trace/bpf_trace.c b/kernel/trace/bpf_trace.c
index 460a031c77e5..8425bf193f39 100644
--- a/kernel/trace/bpf_trace.c
+++ b/kernel/trace/bpf_trace.c
@@ -248,8 +248,8 @@ BPF_CALL_2(bpf_perf_event_read, struct bpf_map *, map, u64, 
flags)
                return -ENOENT;
 
        event = ee->event;
-       if (unlikely(event->attr.type != PERF_TYPE_HARDWARE &&
-                    event->attr.type != PERF_TYPE_RAW))
+       if (unlikely(event->attr.type == PERF_TYPE_SOFTWARE &&
+                    event->attr.config == PERF_COUNT_SW_BPF_OUTPUT))
                return -EINVAL;
 
        /* make sure event is local and doesn't have pmu::count */
-- 
2.9.3