trace.py: add option to show multiline backtrace

The format of backtrace output from trace.py is not very
human friendly so this patch adds new option - '-l', '--multiline'.

New output:

0xffff8000021e5040 >/tests/tst-tcp  1         0.174132344 tcp_state            tp=0xffffa00001dcd800, CLOSED -> CLOSED
  tcpcb::set_state(int)
  tcp_attach
  tcp_usr_attach
  socreate
  socreate(int, int, int)
  sys_socket
  linux_socket
  socket
  0x1000000e83b1
  0x200000700f1b
  0x1000000e859f

0xffff8000021e5040 >/tests/tst-tcp  1         0.174145515 tcp_state            tp=0xffffa00001dcd800, CLOSED -> LISTEN
  tcpcb::set_state(int)
  tcp_usr_listen
  sys_listen
  listen
  0x1000000e842c

vs the regular one:

0xffff8000021e5040 >/tests/tst-tcp  1         0.174132344 tcp_state            tp=0xffffa00001dcd800, CLOSED -> CLOSED   [tcpcb::set_state(int), tcp_attac h, tcp_usr_attach, socreate, socreate(int, int, int), sys_socket, linux_socket, socket, 0x1000000e83b1, 0x200000700f1b, 0x1000000e859f]
0xffff8000021e5040 >/tests/tst-tcp  1         0.174145515 tcp_state            tp=0xffffa00001dcd800, CLOSED -> LISTEN   [tcpcb::set_state(int), tcp_usr_l isten, sys_listen, listen, 0x1000000e842c]

Signed-off-by: Waldemar Kozaczuk <[email protected]>

scripts/loader.py

@@ -1309,7 +1309,7 @@ def make_symbolic(addr):
 
 def dump_trace(out_func):
     indents = defaultdict(int)
-    bt_formatter = BacktraceFormatter(symbol_resolver, symbol_formatter)
+    bt_formatter = BacktraceFormatter(symbol_resolver, symbol_formatter, True)
 
     def lookup_tp(name):
         return gdb.lookup_global_symbol(name).value().dereference()

scripts/osv/trace.py

@@ -22,25 +22,29 @@ def format_time(time):
     return "%12.9f" % nanos_to_seconds(time)
 
 class BacktraceFormatter:
-    def __init__(self, resolver, formatter):
+    def __init__(self, resolver, formatter, multiline):
         self.resolver = resolver
         self.formatter = formatter
+        self.multiline = multiline
 
     def __call__(self, backtrace):
         if not backtrace:
             return ''
 
         frames = list(debug.resolve_all(self.resolver, (x - 1 for x in backtrace if x)))
 
-        while frames[0].name and frames[0].name.startswith("tracepoint"):
+        while frames[0].name and (frames[0].name.startswith("tracepoint") or frames[0].filename.endswith("trace.hh")):
             frames.pop(0)
 
-        return '   [' + ', '.join(map(self.formatter, frames)) + ']'
+        if self.multiline:
+            return '\n  ' + '\n  '.join(map(self.formatter, frames)) + '\n'
+        else:
+            return '   [' + ', '.join(map(self.formatter, frames)) + ']'
 
 def simple_symbol_formatter(src_addr):
     return '0x%x' % src_addr.addr
 
-default_backtrace_formatter = BacktraceFormatter(debug.DummyResolver(), simple_symbol_formatter)
+default_backtrace_formatter = BacktraceFormatter(debug.DummyResolver(), simple_symbol_formatter, False)
 
 class TimeRange(object):
     """

scripts/trace.py

@@ -102,7 +102,7 @@ def get_backtrace_formatter(args):
     if not args.backtrace:
         return lambda backtrace: ''
 
-    return trace.BacktraceFormatter(symbol_resolver(args), src_addr_formatter(args))
+    return trace.BacktraceFormatter(symbol_resolver(args), src_addr_formatter(args), True if args.multiline else False)
 
 def list_trace(args):
     def data_formatter(sample):
@@ -667,6 +667,7 @@ def add_trace_listing_options(parser):
     add_symbol_resolution_options(parser)
     parser.add_argument("-b", "--backtrace", action="store_true", help="show backtrace")
     parser.add_argument("--no-header", action="store_true", help="do not show the header")
+    parser.add_argument("-l", "--multiline", action="store_true", help="show backtrace in multiple lines")
 
 def convert_dump(args):
     if os.path.isfile(args.dumpfile):