mirror of
https://github.com/torvalds/linux.git
synced 2024-12-25 12:21:37 +00:00
5ed3ccbd5a
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>
28 lines
611 B
C
28 lines
611 B
C
#include <linux/ptrace.h>
|
|
#include <linux/version.h>
|
|
#include <uapi/linux/bpf.h>
|
|
#include "bpf_helpers.h"
|
|
|
|
struct bpf_map_def SEC("maps") my_map = {
|
|
.type = BPF_MAP_TYPE_PERF_EVENT_ARRAY,
|
|
.key_size = sizeof(int),
|
|
.value_size = sizeof(u32),
|
|
.max_entries = 32,
|
|
};
|
|
|
|
SEC("kprobe/sys_write")
|
|
int bpf_prog1(struct pt_regs *ctx)
|
|
{
|
|
u64 count;
|
|
u32 key = bpf_get_smp_processor_id();
|
|
char fmt[] = "CPU-%d %llu\n";
|
|
|
|
count = bpf_perf_event_read(&my_map, key);
|
|
bpf_trace_printk(fmt, sizeof(fmt), key, count);
|
|
|
|
return 0;
|
|
}
|
|
|
|
char _license[] SEC("license") = "GPL";
|
|
u32 _version SEC("version") = LINUX_VERSION_CODE;
|