Introduce a BPF program to trigger AUX pause and resume.

Once a attached tracepoint is hit, the BPF program calls the
bpf_perf_event_aux_pause() kfunc for controlling AUX trace.

Signed-off-by: Leo Yan <leo....@arm.com>
---
 tools/perf/Makefile.perf                      |   1 +
 tools/perf/util/bpf_skel/auxtrace_pause.bpf.c | 156 ++++++++++++++++++++++++++
 2 files changed, 157 insertions(+)

diff --git a/tools/perf/Makefile.perf b/tools/perf/Makefile.perf
index 
d4c7031b01a77f4a42326e4c9a88d8a352143178..8fdd24ba4c25ff4a69925a8e0c85bc78dd4fda47
 100644
--- a/tools/perf/Makefile.perf
+++ b/tools/perf/Makefile.perf
@@ -1179,6 +1179,7 @@ SKELETONS += $(SKEL_OUT)/kwork_trace.skel.h 
$(SKEL_OUT)/sample_filter.skel.h
 SKELETONS += $(SKEL_OUT)/kwork_top.skel.h $(SKEL_OUT)/syscall_summary.skel.h
 SKELETONS += $(SKEL_OUT)/bench_uprobe.skel.h
 SKELETONS += $(SKEL_OUT)/augmented_raw_syscalls.skel.h
+SKELETONS += $(SKEL_OUT)/auxtrace_pause.skel.h
 
 $(SKEL_TMP_OUT) $(LIBAPI_OUTPUT) $(LIBBPF_OUTPUT) $(LIBPERF_OUTPUT) 
$(LIBSUBCMD_OUTPUT) $(LIBSYMBOL_OUTPUT):
        $(Q)$(MKDIR) -p $@
diff --git a/tools/perf/util/bpf_skel/auxtrace_pause.bpf.c 
b/tools/perf/util/bpf_skel/auxtrace_pause.bpf.c
new file mode 100644
index 
0000000000000000000000000000000000000000..37f8e1d096a3098415f6469014652dea948044d2
--- /dev/null
+++ b/tools/perf/util/bpf_skel/auxtrace_pause.bpf.c
@@ -0,0 +1,156 @@
+// SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+// Copyright 2025 Arm Limited
+#include "vmlinux.h"
+#include <bpf/bpf_helpers.h>
+#include <bpf/bpf_tracing.h>
+
+struct {
+       __uint(type, BPF_MAP_TYPE_HASH);
+       __uint(key_size, sizeof(__u32));
+       __uint(value_size, sizeof(__u8));
+       __uint(max_entries, 1);
+} cpu_filter SEC(".maps");
+
+struct {
+       __uint(type, BPF_MAP_TYPE_HASH);
+       __uint(key_size, sizeof(__u32));
+       __uint(value_size, sizeof(__u8));
+       __uint(max_entries, 1);
+} task_filter SEC(".maps");
+
+struct {
+       __uint(type, BPF_MAP_TYPE_PERF_EVENT_ARRAY);
+       __uint(key_size, sizeof(__u32));
+       __uint(value_size, sizeof(int));
+       __uint(max_entries, 1);
+} events SEC(".maps");
+
+int enabled = 0;
+
+const volatile int has_cpu = 0;
+const volatile int has_task = 0;
+const volatile int per_thread = 0;
+
+int bpf_perf_event_aux_pause(void *map, u64 flags, bool pause) __ksym;
+
+static int event_aux_pause(void)
+{
+       __u64 flag;
+       __u32 cpu = bpf_get_smp_processor_id();
+
+       if (!enabled)
+               return 0;
+
+       if (has_cpu) {
+               __u8 *ok;
+
+               ok = bpf_map_lookup_elem(&cpu_filter, &cpu);
+               if (!ok)
+                       return 0;
+       }
+
+       if (has_task) {
+               __u32 pid = bpf_get_current_pid_tgid() & 0xffffffff;
+               __u8 *ok;
+
+               ok = bpf_map_lookup_elem(&task_filter, &pid);
+               if (!ok)
+                       return 0;
+       }
+
+       flag = per_thread ? 0 : BPF_F_CURRENT_CPU;
+       bpf_perf_event_aux_pause(&events, flag, true);
+       return 0;
+}
+
+static int event_aux_resume(void)
+{
+       __u64 flag;
+       __u32 cpu = bpf_get_smp_processor_id();
+
+       if (!enabled)
+               return 0;
+
+       if (has_cpu) {
+               __u8 *ok;
+
+               ok = bpf_map_lookup_elem(&cpu_filter, &cpu);
+               if (!ok)
+                       return 0;
+       }
+
+       if (has_task) {
+               __u32 pid = bpf_get_current_pid_tgid() & 0xffffffff;
+               __u8 *ok;
+
+               ok = bpf_map_lookup_elem(&task_filter, &pid);
+               if (!ok)
+                       return 0;
+       }
+
+       flag = per_thread ? 0 : BPF_F_CURRENT_CPU;
+       bpf_perf_event_aux_pause(&events, flag, false);
+       return 0;
+}
+
+SEC("kprobe/func_pause")
+int BPF_PROG(kprobe_event_pause)
+{
+       return event_aux_pause();
+}
+
+SEC("kprobe/func_resume")
+int BPF_PROG(kprobe_event_resume)
+{
+       return event_aux_resume();
+}
+
+SEC("kretprobe/func_pause")
+int BPF_PROG(kretprobe_event_pause)
+{
+       return event_aux_pause();
+}
+
+SEC("kretprobe/func_resume")
+int BPF_PROG(kretprobe_event_resume)
+{
+       return event_aux_resume();
+}
+
+SEC("uprobe/func_pause")
+int BPF_PROG(uprobe_event_pause)
+{
+       return event_aux_pause();
+}
+
+SEC("uprobe/func_resume")
+int BPF_PROG(uprobe_event_resume)
+{
+       return event_aux_resume();
+}
+
+SEC("uretprobe/func_pause")
+int BPF_PROG(uretprobe_event_pause)
+{
+       return event_aux_pause();
+}
+
+SEC("uretprobe/func_resume")
+int BPF_PROG(uretprobe_event_resume)
+{
+       return event_aux_resume();
+}
+
+SEC("tp/func_pause")
+int BPF_PROG(tp_event_pause)
+{
+       return event_aux_pause();
+}
+
+SEC("tp/func_resume")
+int BPF_PROG(tp_event_resume)
+{
+       return event_aux_resume();
+}
+
+char LICENSE[] SEC("license") = "Dual BSD/GPL";

-- 
2.34.1


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