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![Alexei Starovoitov](/assets/img/avatar_default.png)
Performance test and example of bpf_perf_event_output(). kprobe is attached to sys_write() and trivial bpf program streams pid+cookie into userspace via PERF_COUNT_SW_BPF_OUTPUT event. Usage: $ sudo ./bld_x64/samples/bpf/trace_output recv 2968913 events per sec Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
31 lines
642 B
C
31 lines
642 B
C
#include <linux/ptrace.h>
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#include <linux/version.h>
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#include <uapi/linux/bpf.h>
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#include "bpf_helpers.h"
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struct bpf_map_def SEC("maps") my_map = {
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.type = BPF_MAP_TYPE_PERF_EVENT_ARRAY,
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.key_size = sizeof(int),
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.value_size = sizeof(u32),
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.max_entries = 2,
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};
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SEC("kprobe/sys_write")
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int bpf_prog1(struct pt_regs *ctx)
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{
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struct S {
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u64 pid;
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u64 cookie;
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} data;
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memset(&data, 0, sizeof(data));
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data.pid = bpf_get_current_pid_tgid();
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data.cookie = 0x12345678;
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bpf_perf_event_output(ctx, &my_map, 0, &data, sizeof(data));
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return 0;
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}
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char _license[] SEC("license") = "GPL";
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u32 _version SEC("version") = LINUX_VERSION_CODE;
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