alistair23-linux/tools/testing/selftests/bpf/urandom_read.c
Song Liu 13790d1cc7 bpf: add selftest for stackmap with build_id in NMI context
This new test captures stackmap with build_id with hardware event
PERF_COUNT_HW_CPU_CYCLES.

Because we only support one ips-to-build_id lookup per cpu in NMI
context, stack_amap will not be able to do the lookup in this test.
Therefore, we didn't do compare_stack_ips(), as it will alwasy fail.

urandom_read.c is extended to run configurable cycles so that it can be
caught by the perf event.

Signed-off-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-05-14 23:29:45 +02:00

29 lines
419 B
C

#include <stdio.h>
#include <unistd.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <stdlib.h>
#define BUF_SIZE 256
int main(int argc, char *argv[])
{
int fd = open("/dev/urandom", O_RDONLY);
int i;
char buf[BUF_SIZE];
int count = 4;
if (fd < 0)
return 1;
if (argc == 2)
count = atoi(argv[1]);
for (i = 0; i < count; ++i)
read(fd, buf, BUF_SIZE);
close(fd);
return 0;
}