Recover memory mappings before writing dump on ChromeOS

On Linux, breakpad relies on /proc/[pid]/maps to associate symbols from
addresses. ChromeOS' hugepage implementation replaces some segments
with anonymous private pages, which is a restriction of current
implementation in Linux kernel at the time of writing. Thus, breakpad
can no longer symbolize addresses from those text segments replaced by
hugepages.

This patch tries to recover the mappings. Because hugepages are always
inserted in between some .text sections, it tries to infer the names and
offsets of the segments, by looking at segments immediately precede and
succeed them.

For example, a text segment before hugepage optimization
  02001000-03002000 r-xp /opt/google/chrome/chrome

can be broken into
  02001000-02200000 r-xp /opt/google/chrome/chrome
  02200000-03000000 r-xp
  03000000-03002000 r-xp /opt/google/chrome/chrome

BUG=crbug.com/628040
R=mark@chromium.org

Review URL: https://codereview.chromium.org/2161713002 .

Patch from Ting-Yuan (Leo) Huang <laszio@chromium.org>.
1 file changed
tree: 72b0b19d47f3337dcc0aa55eb375a01d1276d715
  1. .gitignore
  2. .travis.yml
  3. AUTHORS
  4. ChangeLog
  5. DEPS
  6. INSTALL
  7. LICENSE
  8. Makefile.am
  9. Makefile.in
  10. NEWS
  11. README.ANDROID
  12. README.md
  13. aclocal.m4
  14. android/
  15. autotools/
  16. breakpad-client.pc.in
  17. breakpad.pc.in
  18. codereview.settings
  19. configure
  20. configure.ac
  21. docs/
  22. m4/
  23. scripts/
  24. src/
README.md

Breakpad

Breakpad is a set of client and server components which implement a crash-reporting system.

Getting started (from master)

  1. First, download depot_tools and ensure that they're in your PATH.

  2. Create a new directory for checking out the source code (it must be named breakpad).

    mkdir breakpad && cd breakpad
    
  3. Run the fetch tool from depot_tools to download all the source repos.

    fetch breakpad
    cd src
    
  4. Build the source.

    ./configure && make
    

    You can also cd to another directory and run configure from there to build outside the source tree.

    This will build the processor tools (src/processor/minidump_stackwalk, src/processor/minidump_dump, etc), and when building on Linux it will also build the client libraries and some tools (src/tools/linux/dump_syms/dump_syms, src/tools/linux/md2core/minidump-2-core, etc).

  5. Optionally, run tests.

    make check
    
  6. Optionally, install the built libraries

    make install
    

If you need to reconfigure your build be sure to run make distclean first.

To update an existing checkout to a newer revision, you can git pull as usual, but then you should run gclient sync to ensure that the dependent repos are up-to-date.

To request change review

  1. Follow the steps above to get the source and build it.

  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. Commit your changes to your local repo and upload them to the server. http://dev.chromium.org/developers/contributing-code e.g. git commit ... && git cl upload ... You will be prompted for credential and a description.

  4. At https://codereview.chromium.org/ 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