ELF modules are loaded in memory in several, possibly discontiguous,
segments. If the holes between segments are large enough, other things,
possibly other ELF modules may be mapped in that space. Crashpad
records the range of modules as the base address of the lowest mapped
segment to the high address of the highest mapped segment. This means
that when one module is mapped into a hole in another, it appears to
the Breakpad processor as overlapping modules. Module ranges are
relevant to the Breakpad processor during stackwalking for identifying
which module a particular program counter belongs to (i.e. mapping the
address to a module's text segment). This patch addresses this issue of
overlapping modules by truncating the range of the module with the
lower base address. A typical module's text segment is the first loaded
segment which would leave the text segment range unaffected. Module
producers can restrict the size of holes in their ELF modules with the
flag "-Wl,-z,max-page-size=4096", preventing other modules from being
mapped in their address range.
Properly contemplating ELF module address ranges would require
extensions to the minidump format to encode any holes.
crbug.com/crashpad/298
This patch also renames the concept of "shrinking down" (which
truncated the upper of two overlapping ranges) to "truncate upper".
Change-Id: I4599201f1e43918db036c390961f8b39e3af1849
Reviewed-on: https://chromium-review.googlesource.com/c/breakpad/breakpad/+/1646932
Reviewed-by: Mark Mentovai <mark@chromium.org>
This CL hits lots of source files because:
1. An update to the CodeModule virtual class. I added an is_loaded
method to specify whether the module is loaded. There were several
mocks/test classes that needed to be updated with an implementation.
An alternative to this route would be to modify
MinidumpUnloadedModule::code_file to prepend "Unloaded_" to the
module name.
2. Added an unloaded_modules parameter to
StackFrameSymbolizer::FillSourceLineInfo.
BUG=
Change-Id: Ic9c7f7c7b7e932a154a5d4ccf292c1527d8da09f
Reviewed-on: https://chromium-review.googlesource.com/430241
Reviewed-by: Ivan Penkov <ivanpe@chromium.org>
For more details take a look at common/using_std_string.h
BUG=
Change-Id: Ifebfc57f691ef3a3bef8cfed7106c567985edffc
Reviewed-on: https://chromium-review.googlesource.com/399738
Reviewed-by: Mark Mentovai <mark@chromium.org>
This change is resolving an issue that was caused by the combination of:
- Android system libraries being relro packed in N+.
- Breakpad dealing with relro packed libraries in a hack way.
This is a fix for http://crbug/611824.
I also found an use-after-free issue (bug in Minidump::SeekToStreamType). I disallowed the MinidumpStreamInfo copy and assign constructors and the compiler detected another similar issue in Minidump::Print. Then I disabled the copy and assign constructors for most classes in minidump.h (just in case). There are a couple of classes where I couldn't disallow them (since assign is used). This will require a small refactor so I left it out of this CL.
R=mark@chromium.org
Review URL: https://codereview.chromium.org/2060663002 .
More specifically:
- Detect corrupt symbols during minidump processing and provide the list of modules with corrupt symbols in the ProcessState. This will allow listing the corrupt symbol files in the final crash report.
- Skip and recover from symbol data parse errors - don't give up until 100 parse errors are seen.
- In order to recover from '\0' (null terminator) in the middle of a symbol file, a couple of methods have to be updated to require both buffer pointer and length. Previously they required only a buffer pointer (char *) and the size of the buffer was evaluated using strlen which is not reliable when the data is corrupt. Most of the changes are due to these signature updates.
- Added and updated unittests.
Also, updated minidump_stackwalk to show a WARNING for corrupt symbols. Output looks like this:
...
Loaded modules:
0x000da000 - 0x000dafff Google Chrome Canary ??? (main)
0x000e0000 - 0x0417dfff Google Chrome Framework 0.1500.0.3 (WARNING: Corrupt symbols, Google Chrome Framework, 4682A6B4136436C4BFECEB62D498020E0)
0x044a8000 - 0x04571fff IOBluetooth 0.1.0.0
...
Review URL: https://breakpad.appspot.com/613002
git-svn-id: http://google-breakpad.googlecode.com/svn/trunk@1200 4c0a9323-5329-0410-9bdc-e9ce6186880e
Issue 53001 (http://breakpad.appspot.com/53001) defines the
TestAssembler classes; those, along with a new set of mock classes
defined in stackwalker_unittest_utils.h, make it possible for us to
actually do proper unit testing of a stack walker. These tests get us
full code coverage for stackwalker_x86.cc.
a=jimblandy, r=mmentovai
git-svn-id: http://google-breakpad.googlecode.com/svn/trunk@548 4c0a9323-5329-0410-9bdc-e9ce6186880e
