This is the mail archive of the
gdb-testers@sourceware.org
mailing list for the GDB project.
[binutils-gdb] gdb.python/py-unwind: Disable stack protection
- From: sergiodj+buildbot at sergiodj dot net
- To: gdb-testers at sourceware dot org
- Date: Fri, 21 Jul 2017 18:30:04 -0400
- Subject: [binutils-gdb] gdb.python/py-unwind: Disable stack protection
- Authentication-results: sourceware.org; auth=none
*** TEST RESULTS FOR COMMIT dcd27ddf875d6b913f1ddb0573c22b0931e36061 ***
Author: Simon Marchi <simon.marchi@ericsson.com>
Branch: master
Commit: dcd27ddf875d6b913f1ddb0573c22b0931e36061
gdb.python/py-unwind: Disable stack protection
[I made some typo fixes but forgot to amend my commit before sending the patch,
hence this v2.]
I see the following failure on Ubuntu 16.04's gcc 5.4.0:
Running /home/emaisin/src/binutils-gdb/gdb/testsuite/gdb.python/py-unwind.exp ...
FAIL: gdb.python/py-unwind.exp: continue to breakpoint: break backtrace-broken
FAIL: gdb.python/py-unwind.exp: Backtrace restored by unwinder (pattern 1)
The problem is that the test expects a very particular stack layout.
When stack protection is enabled, it adds a canary value which looks
like an additional local variable. This makes the test complain about
a bad stack layout and fail.
The simple solution is to disable stack protection for that test using
-fno-stack-protector. I checked older compilers (gcc 4.4, clang 3.5)
and they support that flag, so I don't think it's necessary to probe for
whether the compiler supports it.
Maybe a better solution would be to change the test to make it cope with
different stack layouts (perhaps it could save addresses of stuff in
some global variables which GDB/the unwinder would read). I'll go with
the simple solution for now though.
gdb/testsuite/ChangeLog:
* gdb.python/py-unwind.exp: Disable stack protection when
building test file.