These changes are the raw update to linux-4.4.6-rt14. Kernel sources

[kvmfornfv.git] / kernel / samples / bpf / tracex5_user.c

diff --git a/kernel/samples/bpf/tracex5_user.c b/kernel/samples/bpf/tracex5_user.c
new file mode 100644 (file)
index 0000000..a04dd3c
--- /dev/null
+++ b/kernel/samples/bpf/tracex5_user.c
@@ -0,0 +1,46 @@
+#include <stdio.h>
+#include <linux/bpf.h>
+#include <unistd.h>
+#include <linux/filter.h>
+#include <linux/seccomp.h>
+#include <sys/prctl.h>
+#include "libbpf.h"
+#include "bpf_load.h"
+
+/* install fake seccomp program to enable seccomp code path inside the kernel,
+ * so that our kprobe attached to seccomp_phase1() can be triggered
+ */
+static void install_accept_all_seccomp(void)
+{
+       struct sock_filter filter[] = {
+               BPF_STMT(BPF_RET+BPF_K, SECCOMP_RET_ALLOW),
+       };
+       struct sock_fprog prog = {
+               .len = (unsigned short)(sizeof(filter)/sizeof(filter[0])),
+               .filter = filter,
+       };
+       if (prctl(PR_SET_SECCOMP, 2, &prog))
+               perror("prctl");
+}
+
+int main(int ac, char **argv)
+{
+       FILE *f;
+       char filename[256];
+
+       snprintf(filename, sizeof(filename), "%s_kern.o", argv[0]);
+
+       if (load_bpf_file(filename)) {
+               printf("%s", bpf_log_buf);
+               return 1;
+       }
+
+       install_accept_all_seccomp();
+
+       f = popen("dd if=/dev/zero of=/dev/null count=5", "r");
+       (void) f;
+
+       read_trace_pipe();
+
+       return 0;
+}