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-rw-r--r--samples/bpf/tracex5_user.c50
1 files changed, 50 insertions, 0 deletions
diff --git a/samples/bpf/tracex5_user.c b/samples/bpf/tracex5_user.c
new file mode 100644
index 000000000..c4ab91c89
--- /dev/null
+++ b/samples/bpf/tracex5_user.c
@@ -0,0 +1,50 @@
+// SPDX-License-Identifier: GPL-2.0
+#include <stdio.h>
+#include <linux/bpf.h>
+#include <unistd.h>
+#include <linux/filter.h>
+#include <linux/seccomp.h>
+#include <sys/prctl.h>
+#include <bpf/bpf.h>
+#include "bpf_load.h"
+#include <sys/resource.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];
+ struct rlimit r = {RLIM_INFINITY, RLIM_INFINITY};
+
+ snprintf(filename, sizeof(filename), "%s_kern.o", argv[0]);
+ setrlimit(RLIMIT_MEMLOCK, &r);
+
+ 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;
+}