One-time hack for BCC's argdist to support Unicode strings

argdist-unicode.patch

diff --git a/build/../tools/argdist.py b/usr/share/bcc/tools/argdist
index 61f8e00..746d1b7 100755
--- a/build/../tools/argdist.py
+++ b/usr/share/bcc/tools/argdist
@@ -451,7 +451,10 @@ DATA_DECL
                 # Most fields can be converted with plain str(), but strings
                 # are wrapped in a __string_t which has an .s field
                 if "__string_t" in type(v).__name__:
-                        return str(v.s)
+                        s = bytearray(v.s)
+                        i = s.find('\x00\x00')
+                        s = s[:i]
+                        return s.decode("utf-8")
                 return str(v)

         def _display_expr(self, i):
@@ -641,7 +644,7 @@ argdist -p 2780 -z 120 \\

         def _generate_program(self):
                 bpf_source = """
-struct __string_t { char s[%d]; };
+struct __string_t { u8 s[%d]; };

 #include <uapi/linux/ptrace.h>
                 """ % self.args.string_size