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| author |   Yonghong Song <yhs@fb.com> | 2017-10-23 23:53:08 -0700 |
|---|---|---|
| committer |   David S. Miller <davem@davemloft.net> | 2017-10-25 10:47:47 +0900 |
| commit | e87c6bc3852b981e71c757be20771546ce9f76f3 (patch) | |
| tree | bad3be630137d8e873f4ad5a1ea77b4aa1853184 /samples | |
| parent | bpf: use the same condition in perf event set/free bpf handler (diff) | |
| download | linux-dev-e87c6bc3852b981e71c757be20771546ce9f76f3.tar.xz linux-dev-e87c6bc3852b981e71c757be20771546ce9f76f3.zip | |
bpf: permit multiple bpf attachments for a single perf event
This patch enables multiple bpf attachments for a
kprobe/uprobe/tracepoint single trace event.
Each trace_event keeps a list of attached perf events.
When an event happens, all attached bpf programs will
be executed based on the order of attachment.
A global bpf_event_mutex lock is introduced to protect
prog_array attaching and detaching. An alternative will
be introduce a mutex lock in every trace_event_call
structure, but it takes a lot of extra memory.
So a global bpf_event_mutex lock is a good compromise.
The bpf prog detachment involves allocation of memory.
If the allocation fails, a dummy do-nothing program
will replace to-be-detached program in-place.
Signed-off-by: Yonghong Song <yhs@fb.com>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'samples')
0 files changed, 0 insertions, 0 deletions