LXR linux/samples/bpf/tracex5

   1#include <stdio.h>
   2#include <linux/bpf.h>
   3#include <unistd.h>
   4#include <linux/filter.h>
   5#include <linux/seccomp.h>
   6#include <sys/prctl.h>
   7#include "libbpf.h"
   8#include "bpf_load.h"
   9#include <sys/resource.h>
  10
  11/* install fake seccomp program to enable seccomp code path inside the kernel,
  12 * so that our kprobe attached to seccomp_phase1() can be triggered
  13 */
  14static void install_accept_all_seccomp(void)
  15{
  16        struct sock_filter filter[] = {
  17                BPF_STMT(BPF_RET+BPF_K, SECCOMP_RET_ALLOW),
  18        };
  19        struct sock_fprog prog = {
  20                .len = (unsigned short)(sizeof(filter)/sizeof(filter[0])),
  21                .filter = filter,
  22        };
  23        if (prctl(PR_SET_SECCOMP, 2, &prog))
  24                perror("prctl");
  25}
  26
  27int main(int ac, char **argv)
  28{
  29        FILE *f;
  30        char filename[256];
  31        struct rlimit r = {RLIM_INFINITY, RLIM_INFINITY};
  32
  33        snprintf(filename, sizeof(filename), "%s_kern.o", argv[0]);
  34        setrlimit(RLIMIT_MEMLOCK, &r);
  35
  36        if (load_bpf_file(filename)) {
  37                printf("%s", bpf_log_buf);
  38                return 1;
  39        }
  40
  41        install_accept_all_seccomp();
  42
  43        f = popen("dd if=/dev/zero of=/dev/null count=5", "r");
  44        (void) f;
  45
  46        read_trace_pipe();
  47
  48        return 0;
  49}
  50