[asan_symbolize] Avoid blocking when llvm-symbolizer is installed as addr2line
Summary:
Currently, llvm-symbolizer will print -1 when presented with -1 and not
print a second line. In that case we will block for ever trying to read
the file name. This also happens for non-existent files, in which case GNU
addr2line exits immediate, but llvm-symbolizer does not (see
https://llvm.org/PR42754). While touching these lines, I also added some
more debug logging to help diagnose this and potential future issues.
Reviewers: kcc, eugenis, glider, samsonov
Reviewed By: eugenis
Subscribers: kubamracek, #sanitizers, llvm-commits
Tags: #sanitizers, #llvm
Differential Revision: https://reviews.llvm.org/D65322
git-svn-id: https://llvm.org/svn/llvm-project/compiler-rt/trunk@369924 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/asan/scripts/asan_symbolize.py b/lib/asan/scripts/asan_symbolize.py
index d3f7032..8ea68b3 100755
--- a/lib/asan/scripts/asan_symbolize.py
+++ b/lib/asan/scripts/asan_symbolize.py
@@ -27,6 +27,7 @@
import re
import subprocess
import sys
+from distutils.spawn import find_executable
symbolizers = {}
demangle = False
@@ -153,6 +154,7 @@
addr2line_tool = 'addr2line'
if binutils_prefix:
addr2line_tool = binutils_prefix + addr2line_tool
+ logging.debug('addr2line binary is %s' % find_executable(addr2line_tool))
cmd = [addr2line_tool, '-fi']
if demangle:
cmd += ['--demangle']
@@ -174,14 +176,34 @@
is_first_frame = True
while True:
function_name = self.pipe.stdout.readline().rstrip()
+ logging.debug("read function_name='%s' from addr2line" % function_name)
+ # If llvm-symbolizer is installed as addr2line, older versions of
+ # llvm-symbolizer will print -1 when presented with -1 and not print
+ # a second line. In that case we will block for ever trying to read the
+ # file name. This also happens for non-existent files, in which case GNU
+ # addr2line exits immediate, but llvm-symbolizer does not (see
+ # https://llvm.org/PR42754).
+ if function_name == '-1':
+ logging.debug("got function '-1' -> no more input")
+ break
file_name = self.pipe.stdout.readline().rstrip()
+ logging.debug("read file_name='%s' from addr2line" % file_name)
if is_first_frame:
is_first_frame = False
- elif function_name in ['', '??']:
- assert file_name == function_name
+ elif function_name == '??':
+ assert file_name == '??:0', file_name
+ logging.debug("got function '??' -> no more input")
+ break
+ elif not function_name:
+ assert not file_name, file_name
+ logging.debug("got empty function name -> no more input")
break
lines.append((function_name, file_name));
- except Exception:
+ except BrokenPipeError:
+ logging.debug("got broken pipe, addr2line returncode=%d" % self.pipe.poll())
+ lines.append(('??', '??:0'))
+ except Exception as e:
+ logging.debug("got unknown exception communicating with addr2line", exc_info=e)
lines.append(('??', '??:0'))
return ['%s in %s %s' % (addr, function, fix_filename(file)) for (function, file) in lines]
diff --git a/test/asan/TestCases/Posix/asan-symbolize-bad-path.cpp b/test/asan/TestCases/Posix/asan-symbolize-bad-path.cpp
index 3f93122..057a4de 100644
--- a/test/asan/TestCases/Posix/asan-symbolize-bad-path.cpp
+++ b/test/asan/TestCases/Posix/asan-symbolize-bad-path.cpp
@@ -1,4 +1,15 @@
// Test that asan_symbolize does not hang when provided with an non-existing
// path.
-// RUN: echo '#0 0xabcdabcd (%t/bad/path+0x1234)' | %asan_symbolize | FileCheck %s
-// CHECK: #0 0xabcdabcd
+// RUN: echo '#0 0xabcdabcd (%t/bad/path+0x1234)' | %asan_symbolize | FileCheck %s -check-prefix CHECK-BAD-FILE
+// CHECK-BAD-FILE: #0 0xabcdabcd in ?? ??:0
+// CHECK-BAD-FILE-EMPTY:
+
+// Also test that asan_symbolize doesn't assert on an invalid address with a valid file:
+// RUN: %clangxx_asan -O0 %s -o %t
+// RUN: echo '#0 0xabcdabcd (%t+0x0)' | %asan_symbolize | FileCheck %s -check-prefix CHECK-BAD-ADDR
+// CHECK-BAD-ADDR: #0 0xabcdabcd in ??
+// CHECK-BAD-ADDR-EMPTY:
+
+int main() {
+ return 0;
+}
