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

[kvmfornfv.git] / kernel / samples / bpf / tracex5_kern.c

diff --git a/kernel/samples/bpf/tracex5_kern.c b/kernel/samples/bpf/tracex5_kern.c
new file mode 100644 (file)
index 0000000..b3f4295
--- /dev/null
+++ b/kernel/samples/bpf/tracex5_kern.c
@@ -0,0 +1,75 @@
+/* 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 "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),
+       .max_entries = 1024,
+};
+
+SEC("kprobe/seccomp_phase1")
+int bpf_prog1(struct pt_regs *ctx)
+{
+       struct seccomp_data sd = {};
+
+       bpf_probe_read(&sd, sizeof(sd), (void *)PT_REGS_PARM1(ctx));
+
+       /* dispatch into next BPF program depending on syscall number */
+       bpf_tail_call(ctx, &progs, sd.nr);
+
+       /* fall through -> unknown syscall */
+       if (sd.nr >= __NR_getuid && sd.nr <= __NR_getsid) {
+               char fmt[] = "syscall=%d (one of get/set uid/pid/gid)\n";
+               bpf_trace_printk(fmt, sizeof(fmt), sd.nr);
+       }
+       return 0;
+}
+
+/* we jump here when syscall number == __NR_write */
+PROG(__NR_write)(struct pt_regs *ctx)
+{
+       struct seccomp_data sd = {};
+
+       bpf_probe_read(&sd, sizeof(sd), (void *)PT_REGS_PARM1(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(__NR_read)(struct pt_regs *ctx)
+{
+       struct seccomp_data sd = {};
+
+       bpf_probe_read(&sd, sizeof(sd), (void *)PT_REGS_PARM1(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(__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;