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authorYonghong Song <yhs@fb.com>2017-08-05 02:00:10 +0300
committerDavid S. Miller <davem@davemloft.net>2017-08-08 00:09:48 +0300
commit1da236b6be9632255ab034f22aca5b78d7c3c007 (patch)
tree172104216444020892b0fbbd0f4de8a72e8686a9 /samples/bpf/syscall_tp_kern.c
parentcf5f5cea270655dd49370760576c64b228583b79 (diff)
downloadlinux-1da236b6be9632255ab034f22aca5b78d7c3c007.tar.xz
bpf: add a test case for syscalls/sys_{enter|exit}_* tracepoints
Signed-off-by: Yonghong Song <yhs@fb.com> Acked-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'samples/bpf/syscall_tp_kern.c')
-rw-r--r--samples/bpf/syscall_tp_kern.c62
1 files changed, 62 insertions, 0 deletions
diff --git a/samples/bpf/syscall_tp_kern.c b/samples/bpf/syscall_tp_kern.c
new file mode 100644
index 000000000000..9149c524d279
--- /dev/null
+++ b/samples/bpf/syscall_tp_kern.c
@@ -0,0 +1,62 @@
+/* Copyright (c) 2017 Facebook
+ *
+ * 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 <uapi/linux/bpf.h>
+#include "bpf_helpers.h"
+
+struct syscalls_enter_open_args {
+ unsigned long long unused;
+ long syscall_nr;
+ long filename_ptr;
+ long flags;
+ long mode;
+};
+
+struct syscalls_exit_open_args {
+ unsigned long long unused;
+ long syscall_nr;
+ long ret;
+};
+
+struct bpf_map_def SEC("maps") enter_open_map = {
+ .type = BPF_MAP_TYPE_ARRAY,
+ .key_size = sizeof(u32),
+ .value_size = sizeof(u32),
+ .max_entries = 1,
+};
+
+struct bpf_map_def SEC("maps") exit_open_map = {
+ .type = BPF_MAP_TYPE_ARRAY,
+ .key_size = sizeof(u32),
+ .value_size = sizeof(u32),
+ .max_entries = 1,
+};
+
+static __always_inline void count(void *map)
+{
+ u32 key = 0;
+ u32 *value, init_val = 1;
+
+ value = bpf_map_lookup_elem(map, &key);
+ if (value)
+ *value += 1;
+ else
+ bpf_map_update_elem(map, &key, &init_val, BPF_NOEXIST);
+}
+
+SEC("tracepoint/syscalls/sys_enter_open")
+int trace_enter_open(struct syscalls_enter_open_args *ctx)
+{
+ count((void *)&enter_open_map);
+ return 0;
+}
+
+SEC("tracepoint/syscalls/sys_exit_open")
+int trace_enter_exit(struct syscalls_exit_open_args *ctx)
+{
+ count((void *)&exit_open_map);
+ return 0;
+}