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![Kaixu Xia](/assets/img/avatar_default.png)
There are two improvements in this patch: 1. Fix the build warnings; 2. Add function read_trace_pipe() to print the result on the screen; Before this patch, we can get the result through /sys/kernel/de bug/tracing/trace_pipe and get nothing on the screen. By applying this patch, the result can be printed on the screen. $ ./tracex6 ... tracex6-705 [003] d..1 131.428593: : CPU-3 19981414 sshd-683 [000] d..1 131.428727: : CPU-0 221682321 sshd-683 [000] d..1 131.428821: : CPU-0 221808766 sshd-683 [000] d..1 131.428950: : CPU-0 221982984 sshd-683 [000] d..1 131.429045: : CPU-0 222111851 tracex6-705 [003] d..1 131.429168: : CPU-3 20757551 sshd-683 [000] d..1 131.429170: : CPU-0 222281240 sshd-683 [000] d..1 131.429261: : CPU-0 222403340 sshd-683 [000] d..1 131.429378: : CPU-0 222561024 ... Signed-off-by: Kaixu Xia <xiakaixu@huawei.com> Acked-by: Alexei Starovoitov <ast@plumgrid.com> Signed-off-by: David S. Miller <davem@davemloft.net>
27 lines
611 B
C
27 lines
611 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 = 32,
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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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u64 count;
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u32 key = bpf_get_smp_processor_id();
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char fmt[] = "CPU-%d %llu\n";
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count = bpf_perf_event_read(&my_map, key);
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bpf_trace_printk(fmt, sizeof(fmt), key, count);
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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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