v4.19.13 snapshot.
diff --git a/samples/bpf/tracex5_kern.c b/samples/bpf/tracex5_kern.c
new file mode 100644
index 0000000..f57f4e1
--- /dev/null
+++ b/samples/bpf/tracex5_kern.c
@@ -0,0 +1,79 @@
+/* Copyright (c) 2015 PLUMgrid, http://plumgrid.com
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of version 2 of the GNU General Public
+ * License as published by the Free Software Foundation.
+ */
+#include <linux/ptrace.h>
+#include <linux/version.h>
+#include <uapi/linux/bpf.h>
+#include <uapi/linux/seccomp.h>
+#include <uapi/linux/unistd.h>
+#include "syscall_nrs.h"
+#include "bpf_helpers.h"
+
+#define PROG(F) SEC("kprobe/"__stringify(F)) int bpf_func_##F
+
+struct bpf_map_def SEC("maps") progs = {
+ .type = BPF_MAP_TYPE_PROG_ARRAY,
+ .key_size = sizeof(u32),
+ .value_size = sizeof(u32),
+#ifdef __mips__
+ .max_entries = 6000, /* MIPS n64 syscalls start at 5000 */
+#else
+ .max_entries = 1024,
+#endif
+};
+
+SEC("kprobe/__seccomp_filter")
+int bpf_prog1(struct pt_regs *ctx)
+{
+ int sc_nr = (int)PT_REGS_PARM1(ctx);
+
+ /* dispatch into next BPF program depending on syscall number */
+ bpf_tail_call(ctx, &progs, sc_nr);
+
+ /* fall through -> unknown syscall */
+ if (sc_nr >= __NR_getuid && sc_nr <= __NR_getsid) {
+ char fmt[] = "syscall=%d (one of get/set uid/pid/gid)\n";
+ bpf_trace_printk(fmt, sizeof(fmt), sc_nr);
+ }
+ return 0;
+}
+
+/* we jump here when syscall number == __NR_write */
+PROG(SYS__NR_write)(struct pt_regs *ctx)
+{
+ struct seccomp_data sd;
+
+ bpf_probe_read(&sd, sizeof(sd), (void *)PT_REGS_PARM2(ctx));
+ if (sd.args[2] == 512) {
+ char fmt[] = "write(fd=%d, buf=%p, size=%d)\n";
+ bpf_trace_printk(fmt, sizeof(fmt),
+ sd.args[0], sd.args[1], sd.args[2]);
+ }
+ return 0;
+}
+
+PROG(SYS__NR_read)(struct pt_regs *ctx)
+{
+ struct seccomp_data sd;
+
+ bpf_probe_read(&sd, sizeof(sd), (void *)PT_REGS_PARM2(ctx));
+ if (sd.args[2] > 128 && sd.args[2] <= 1024) {
+ char fmt[] = "read(fd=%d, buf=%p, size=%d)\n";
+ bpf_trace_printk(fmt, sizeof(fmt),
+ sd.args[0], sd.args[1], sd.args[2]);
+ }
+ return 0;
+}
+
+PROG(SYS__NR_mmap)(struct pt_regs *ctx)
+{
+ char fmt[] = "mmap\n";
+ bpf_trace_printk(fmt, sizeof(fmt));
+ return 0;
+}
+
+char _license[] SEC("license") = "GPL";
+u32 _version SEC("version") = LINUX_VERSION_CODE;