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fd9f3d8b17
.raSearchStart in the cases where there are alignment operators in the program string. If alignment operators are found in the program string, the current value of %ebp must be valid and it is the only reliable data point that can be used for getting to the previous frame. Previously, the .raSearchStart calculation was based on %esp and when %esp is aligned in the current frame (which is a lossy operation) the resulting .raSearchStart cannot was incorrect. There is code that is trying to work around this problem (scanning of up to 3 words for a return address) which is unreliable and it doesn't work in many cases (e.g. when the alignment is on a 64-byte boundary). This fix is already deployed in Google and it was measured to reduce the number of wrong stack traces (for Windows crashes) by 45%. No regressions have been found so far. Here is an example of an issue that was fixed by this change (where register %esp is aligned on the 64-byte boundary and the workarounds that we already had didn't work): https://code.google.com/p/chromium/issues/detail?id=311359 0:013> uf chrome_59630000!base::MessagePumpForIO::DoRunLoop 518 59685c39 55 push ebp 518 59685c3a 8bec mov ebp,esp 518 59685c3c 83e4c0 and esp,0FFFFFFC0h <== 64-byte boundary 518 59685c3f 83ec34 sub esp,34h 518 59685c42 53 push ebx 518 59685c43 56 push esi Program string contains 64-byte alignment: $T1 .raSearch = $T0 $T1 4 - 64 @ = $ebp $T1 4 - ^ = $eip $T1 ^ = $esp $T1 4 + = $20 $T0 56 - ^ = $23 $T0 60 - ^ = $24 $T0 64 - ^ = Review URL: https://breakpad.appspot.com/694002 git-svn-id: http://google-breakpad.googlecode.com/svn/trunk@1232 4c0a9323-5329-0410-9bdc-e9ce6186880e |
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| android | ||
| autotools | ||
| m4 | ||
| src | ||
| aclocal.m4 | ||
| AUTHORS | ||
| ChangeLog | ||
| codereview.settings | ||
| configure | ||
| configure.ac | ||
| COPYING | ||
| DEPS | ||
| INSTALL | ||
| Makefile.am | ||
| Makefile.in | ||
| NEWS | ||
| README | ||
| README.ANDROID | ||
Breakpad is a set of client and server components which implement a
crash-reporting system.
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Getting started in 32-bit mode (from trunk)
Configure: CXXFLAGS=-m32 CFLAGS=-m32 CPPFLAGS=-m32 ./configure
Build: make
Test: make check
Install: make install
If you need to reconfigure your build be sure to run "make distclean" first.
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To request change review:
0. Get access to a read-write copy of source.
Owners at http://code.google.com/p/google-breakpad/ are able to grant
this access.
1. Check out a read-write copy of source using instructions at
http://code.google.com/p/google-breakpad/source/checkout
2. Make changes. Build and test your changes.
For core code like processor use methods above.
For linux/mac/windows, there are test targets in each project file.
3. Download http://codereview.appspot.com/static/upload.py
4. Run upload.py from the 'src' directory:
upload.py --server=breakpad.appspot.com
You will be prompted for credential and a description.
5. At http://breakpad.appspot.com you'll find your issue listed; click on it,
and select Publish+Mail, and enter in the code reviewer and CC
google-breakpad-dev@googlegroups.com
6. When applying code review feedback, specify the '-i' option when running
upload.py again and pass the issue number so it updates the existing issue,
rather than creating a new one.
Be sure to rerun upload.py from the same directory as you did for previous
uploads to allow for proper diff calculations.