diff options
| author | Yonghong Song <yhs@fb.com> | 2017-10-23 23:53:08 -0700 |
|---|---|---|
| committer | Michael Bestas <mkbestas@lineageos.org> | 2022-04-19 00:51:32 +0300 |
| commit | a85b6c28bb287439916716f124450ceb79a1624f (patch) | |
| tree | faa8839e1d97bcd06a42bc681f86df74734d02fb /kernel/trace/trace_uprobe.c | |
| parent | 3f79f14b62202045de323c754352cee2ac3b1d08 (diff) | |
BACKPORT: 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>
(cherry picked from commit e87c6bc3852b981e71c757be20771546ce9f76f3)
Signed-off-by: Connor O'Brien <connoro@google.com>
Bug: 121213201
Bug: 138317270
Test: build & boot cuttlefish; attach 2 progs to 1 tracepoint
Change-Id: I390d8c0146888ddb1aed5a6f6e5dae7ef394ebc9
Signed-off-by: Chatur27 <jasonbright2709@gmail.com>
Diffstat (limited to 'kernel/trace/trace_uprobe.c')
| -rw-r--r-- | kernel/trace/trace_uprobe.c | 3 |
1 files changed, 1 insertions, 2 deletions
diff --git a/kernel/trace/trace_uprobe.c b/kernel/trace/trace_uprobe.c index e77dfa1e7db7..d86cc7d768f1 100644 --- a/kernel/trace/trace_uprobe.c +++ b/kernel/trace/trace_uprobe.c @@ -1119,13 +1119,12 @@ 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)) + if (bpf_prog_array_valid(call) && !trace_call_bpf(call, regs)) return; esize = SIZEOF_TRACE_ENTRY(is_ret_probe(tu)); |