tracing, perf: Implement BPF programs attached to uprobes

By copying BPF related operation to uprobe processing path, this patch
allow users attach BPF programs to uprobes like what they are already
doing on kprobes.

After this patch, users are allowed to use PERF_EVENT_IOC_SET_BPF on a
uprobe perf event. Which make it possible to profile user space programs
and kernel events together using BPF.

Because of this patch, CONFIG_BPF_EVENTS should be selected by
CONFIG_UPROBE_EVENT to ensure trace_call_bpf() is compiled even if
KPROBE_EVENT is not set.

Signed-off-by: Wang Nan <wangnan0@huawei.com>
Acked-by: Alexei Starovoitov <ast@plumgrid.com>
Cc: Brendan Gregg <brendan.d.gregg@gmail.com>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: David Ahern <dsahern@gmail.com>
Cc: He Kuang <hekuang@huawei.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Kaixu Xia <xiakaixu@huawei.com>
Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Zefan Li <lizefan@huawei.com>
Cc: pi3orama@163.com
Link: http://lkml.kernel.org/r/1435716878-189507-3-git-send-email-wangnan0@huawei.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
This commit is contained in:
Wang Nan 2015-07-01 02:13:50 +00:00 committed by Arnaldo Carvalho de Melo
parent 098d2164e3
commit 04a22fae4c
4 changed files with 13 additions and 3 deletions

View file

@ -243,6 +243,7 @@ enum {
TRACE_EVENT_FL_USE_CALL_FILTER_BIT,
TRACE_EVENT_FL_TRACEPOINT_BIT,
TRACE_EVENT_FL_KPROBE_BIT,
TRACE_EVENT_FL_UPROBE_BIT,
};
/*
@ -257,6 +258,7 @@ enum {
* USE_CALL_FILTER - For trace internal events, don't use file filter
* TRACEPOINT - Event is a tracepoint
* KPROBE - Event is a kprobe
* UPROBE - Event is a uprobe
*/
enum {
TRACE_EVENT_FL_FILTERED = (1 << TRACE_EVENT_FL_FILTERED_BIT),
@ -267,8 +269,11 @@ enum {
TRACE_EVENT_FL_USE_CALL_FILTER = (1 << TRACE_EVENT_FL_USE_CALL_FILTER_BIT),
TRACE_EVENT_FL_TRACEPOINT = (1 << TRACE_EVENT_FL_TRACEPOINT_BIT),
TRACE_EVENT_FL_KPROBE = (1 << TRACE_EVENT_FL_KPROBE_BIT),
TRACE_EVENT_FL_UPROBE = (1 << TRACE_EVENT_FL_UPROBE_BIT),
};
#define TRACE_EVENT_FL_UKPROBE (TRACE_EVENT_FL_KPROBE | TRACE_EVENT_FL_UPROBE)
struct trace_event_call {
struct list_head list;
struct trace_event_class *class;

View file

@ -6846,8 +6846,8 @@ static int perf_event_set_bpf_prog(struct perf_event *event, u32 prog_fd)
if (event->tp_event->prog)
return -EEXIST;
if (!(event->tp_event->flags & TRACE_EVENT_FL_KPROBE))
/* bpf programs can only be attached to kprobes */
if (!(event->tp_event->flags & TRACE_EVENT_FL_UKPROBE))
/* bpf programs can only be attached to u/kprobes */
return -EINVAL;
prog = bpf_prog_get(prog_fd);

View file

@ -434,7 +434,7 @@ config UPROBE_EVENT
config BPF_EVENTS
depends on BPF_SYSCALL
depends on KPROBE_EVENT
depends on KPROBE_EVENT || UPROBE_EVENT
bool
default y
help

View file

@ -1095,11 +1095,15 @@ static void __uprobe_perf_func(struct trace_uprobe *tu,
{
struct trace_event_call *call = &tu->tp.call;
struct uprobe_trace_entry_head *entry;
struct bpf_prog *prog = call->prog;
struct hlist_head *head;
void *data;
int size, esize;
int rctx;
if (prog && !trace_call_bpf(prog, regs))
return;
esize = SIZEOF_TRACE_ENTRY(is_ret_probe(tu));
size = esize + tu->tp.size + dsize;
@ -1289,6 +1293,7 @@ static int register_uprobe_event(struct trace_uprobe *tu)
return -ENODEV;
}
call->flags = TRACE_EVENT_FL_UPROBE;
call->class->reg = trace_uprobe_register;
call->data = tu;
ret = trace_add_event_call(call);