[kvm-unit-tests,v5,4/5] scripts: pretty print stack traces

Commit Message

Peter Feiner March 7, 2016, 5:46 p.m. UTC

The script runs addresses through addr2line to get file names and line
numbers.  Also prints out source code lines if files are available.
For example

0x004013f5: ac_test_exec at x86/access.c:818
            }
      >     ac_test_setup_pte(at, pool);
            r = ac_test_do_access(at);
0x004014dd: ac_test_run at x86/access.c:852
                ++tests;
      >         successes += ac_test_exec(&at, &pool);
            } while (ac_test_bump(&at));
0x0040157d: main at x86/access.c:873
            printf("starting test\n\n");
      >     r = ac_test_run();
            return r ? 0 : 1;
0x0040028e: start64 at x86/cstart64.S:206
                lea __argv(%rip), %rsi
      >         call main
                mov %eax, %edi

Signed-off-by: Peter Feiner <[e-mail]>
---
 scripts/pretty_print_stacks.py | 89 ++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 89 insertions(+)
 create mode 100755 scripts/pretty_print_stacks.py

Patch

diff --git a/scripts/pretty_print_stacks.py b/scripts/pretty_print_stacks.py
new file mode 100755
index 0000000..ee5a52e
--- /dev/null
+++ b/scripts/pretty_print_stacks.py
@@ -0,0 +1,89 @@ 
+#!/usr/bin/env python
+
+import re
+import subprocess
+import sys
+import traceback
+
+# Subvert output buffering.
+def puts(string):
+    sys.stdout.write(string)
+    sys.stdout.flush()
+
+def pretty_print_stack(binary, line):
+    addrs = line.split()[1:]
+    # Addresses are return addresses unless preceded by a '@'. We want the
+    # caller address so line numbers are more intuitive. Thus we subtract 1
+    # from the address to get the call code.
+    for i in range(len(addrs)):
+        addr = addrs[i]
+        if addr.startswith('@'):
+            addrs[i] = addr[1:]
+        else:
+            addrs[i] = '%lx' % (int(addrs[i], 16) - 1)
+
+    # Output like this:
+    #        0x004002be: start64 at path/to/kvm-unit-tests/x86/cstart64.S:208
+    #         (inlined by) test_ept_violation at path/to/kvm-unit-tests/x86/vmx_tests.c:1719 (discriminator 1)
+    cmd = ['addr2line', '-e', binary, '-i', '-f', '--pretty', '--address']
+    cmd.extend(addrs)
+
+    p = subprocess.Popen(cmd, stdout=subprocess.PIPE)
+    out, err = p.communicate()
+    if p.returncode != 0:
+        puts(line)
+        return
+
+    for line in out.splitlines():
+        m = re.match('(.*) at [^ ]*/kvm-unit-tests/([^ ]*):([0-9]+)(.*)', line)
+        if m is None:
+            puts('%s\n' % line)
+            return
+
+        head, path, line, tail = m.groups()
+        line = int(line)
+        puts('%s at %s:%d%s\n' % (head, path, line, tail))
+        try:
+            lines = open(path).readlines()
+        except IOError:
+            continue
+        if line > 1:
+            puts('        %s\n' % lines[line - 2].rstrip())
+        puts('      > %s\n' % lines[line - 1].rstrip())
+        if line < len(lines):
+            puts('        %s\n' % lines[line].rstrip())
+
+def main():
+    if len(sys.argv) != 2:
+        sys.stderr.write('usage: %s <kernel>\n' % sys.argv[0])
+        sys.exit(1)
+
+    binary = sys.argv[1]
+
+    try:
+        while True:
+            # Subvert input buffering.
+            line = sys.stdin.readline()
+            if line == '':
+                break
+
+            if not line.strip().startswith('STACK:'):
+                puts(line)
+                continue
+
+            try:
+                pretty_print_stack(binary, line)
+            except Exception:
+                puts('Error pretty printing stack:\n')
+                puts(traceback.format_exc())
+                puts('Continuing without pretty printing...\n')
+                while True:
+                    puts(line)
+                    line = sys.stdin.readline()
+                    if line == '':
+                        break
+    except:
+        sys.exit(1)
+
+if __name__ == '__main__':
+    main()