If a MinidumpLinuxMapsList was created and destroyed without its Read method,
the program would have a segmentation fault because the destructor did not
check for a null maps_ field. Additional changes include additional
supplementary null checks, a potential memory leak fix, and some comment
removal.
Review URL: https://codereview.chromium.org/1271543002
git-svn-id: http://google-breakpad.googlecode.com/svn/trunk@1478 4c0a9323-5329-0410-9bdc-e9ce6186880e
when checking exploitability rating.
Linux minidumps do not support MD_MEMORY_INFO_LIST_STREAM, meaning the
processor cannot retrieve its memory mappings. However, it has its own
stream, MD_LINUX_MAPS, which contains memory mappings specific to Linux
(it contains the contents of /proc/self/maps). This CL allows the minidump
to gather information from the memory mappings for Linux minidumps.
In addition, exploitability rating for Linux dumps now use memory mappings
instead of checking the ELF headers of binaries. The basis for the change
is that checking the ELF headers requires the minidumps to store the memory
from the ELF headers, while the memory mapping data is already present,
meaning the size of a minidump will be unchanged.
As a result, of removing ELF header analysis, two unit tests have been removed.
Arguably, the cases that those unit tests check do not merit a high
exploitability rating and do not warrant a solid conclusion that was given
earlier.
R=ivanpe@chromium.org
Review URL: https://codereview.chromium.org/1251593007
git-svn-id: http://google-breakpad.googlecode.com/svn/trunk@1476 4c0a9323-5329-0410-9bdc-e9ce6186880e
If the minidump module containing the instruction pointer has memory
containing the ELF header and program header table, when checking the
exploitability rating, the processor will use the ELF header data to determine
if the instruction pointer lies in an executable region of the module, rather
than just checking if it lies in a module.
R=ivanpe@chromium.org
Review URL: https://codereview.chromium.org/1233973002
git-svn-id: http://google-breakpad.googlecode.com/svn/trunk@1472 4c0a9323-5329-0410-9bdc-e9ce6186880e
When I first added the exception whitelist, I meant to put the check before
checking the location of the instruction pointer. (I didn't notice that it
was after the other check until now.) The whitelist check is to quickly rule
out minidumps, and if checking the instruction pointer provided any useful
information, it would be pretty indicative that the exception causing the
dump is interesting.
R=ivanpe@chromium.org
Review URL: https://codereview.chromium.org/1211253009
git-svn-id: http://google-breakpad.googlecode.com/svn/trunk@1469 4c0a9323-5329-0410-9bdc-e9ce6186880e
in valid code for Linux exploitability rating.
This CL adds to the Linux exploitability checker by verifying that the
instruction pointer is in valid code. Verification is done by obtaining a
memory mapping of the crash and checking if the instruction pointer lies in
an executable region. If there is no memory mapping, the instruction pointer
is checked to determine if it lies within a known module.
R=ivanpe@chromium.org
Review URL: https://codereview.chromium.org/1210493003
git-svn-id: http://google-breakpad.googlecode.com/svn/trunk@1464 4c0a9323-5329-0410-9bdc-e9ce6186880e
The current code is relying on info->si_pid to figure out whether
the exception handler was triggered by a signal coming from the kernel
(that will re-trigger until the cause that triggered the signal has
been cleared) or from user-space e.g., kill -SIGNAL pid, which will NOT
automatically re-trigger in the next signal handler in the chain.
While the intentions are good (manually re-triggering user-space
signals), the current implementation mistakenly looks at the si_pid
field in siginfo_t, assuming that it is coming from the kernel if
si_pid == 0.
This is wrong. siginfo_t, in fact, is a union and si_pid is meaningful
only for userspace signals. For signals originated by the kernel,
instead, si_pid overlaps with si_addr (the faulting address).
As a matter of facts, the current implementation is mistakenly
re-triggering the signal using tgkill for most of the kernel-space
signals (unless the fault address is exactly 0x0).
This is not completelly correct for the case of SIGSEGV/SIGBUS. The
next handler in the chain will stil see the signal, but the |siginfo|
and the |context| arguments of the handler will be meaningless
(retriggering a signal with tgkill doesn't preserve them).
Therefore, if the next handler in the chain expects those arguments
to be set, it will fail.
Concretelly, this is causing problems to WebView. In some rare
circumstances, the next handler in the chain is a user-space runtime
which does SIGSEGV handling to implement speculative null pointer
managed exceptions (see as an example
http://www.mono-project.com/docs/advanced/runtime/docs/exception-handling/)
The fix herein proposed consists in using the si_code (see SI_FROMUSER
macros) to determine whether a signal is coming form the kernel
(and therefore just re-establish the next signal handler) or from
userspace (and use the tgkill logic).
Repro case:
This issue is visible in Chrome for Android with this simple repro case:
- Add a non-null pointer dereference in the codebase:
*((volatile int*)0xbeef) = 42
Without this change: the next handler (the libc trap) prints:
F/libc ( 595): Fatal signal 11 (SIGSEGV), code 1, fault addr 0x487
where 0x487 is actually the PID of the process (which is wrong).
With this change: the next handler prints:
F/libc ( 595): Fatal signal 11 (SIGSEGV), code 1, fault addr 0xbeef
which is the correct answer.
BUG=chromium:481937
R=mark@chromium.org
Review URL: https://breakpad.appspot.com/6844002.
git-svn-id: http://google-breakpad.googlecode.com/svn/trunk@1461 4c0a9323-5329-0410-9bdc-e9ce6186880e
The current processor implementation is grepping for /google-breakpad(
in the logcat lines, to filter out microdump lines, which by default
look like this:
W/google-breakpad( 3728): -----BEGIN BREAKPAD MICRODUMP-----
Turns out that logcat format can vary, when passing optional arguments,
and produce something like the following:
04-13 12:30:35.563 6531 6531 W google-breakpad: -----BEGIN ...
In the latter case, the "/google-breakpad(" filter is too aggressive.
This change is relaxing it, so it is compatible also with non-default
logcat arguments.
BUG=640
R=mmandlis@chromium.org
Review URL: https://breakpad.appspot.com/2864002
git-svn-id: http://google-breakpad.googlecode.com/svn/trunk@1442 4c0a9323-5329-0410-9bdc-e9ce6186880e
ACCESS_VIOLATION and IN_PAGE_ERROR both specify
read/write/dep flags and address. ACCESS_VIOLATION currently
reports these, but IN_PAGE_ERROR does not. This change makes
IN_PAGE_ERROR report this information as well, and also the
additional NTSTATUS value for the underlying cause.
Patch by bungeman@chromium.org
Review URL: https://breakpad.appspot.com/1794002/
git-svn-id: http://google-breakpad.googlecode.com/svn/trunk@1441 4c0a9323-5329-0410-9bdc-e9ce6186880e
This feature is enabled only when "-s" is provided as a commandline option.
minidump_stackwalk.cc:
- Add a new commandline option "-s" to output stack contents.
- Instantiate Minidump object in PrintMinidumpProcess() to keep it alive longer so that accessing process_state.thread_memory_regions() in stackwalk_common.cc doesn't result in use-after-free.
stackwalk_common.cc:
- Add a new function PrintStackContents() to output stack contents.
R=mark@chromium.org
Review URL: https://breakpad.appspot.com/9774002
git-svn-id: http://google-breakpad.googlecode.com/svn/trunk@1429 4c0a9323-5329-0410-9bdc-e9ce6186880e
- Filter modules by prot flags (only +x) not extensions. It wouldn't
otherwise catch the case of Chrome mapping the library from the
apk (which is mapped r-x but doesn't end in .so).
- Use compile-time detection of target arch, in order to cope with
multilib OSes, where uname() doesn't reflect the run-time arch.
- Add OS information and CPU arch / count.
- Add support for aarch64.
- Add tests and stackwalk expectations for aarch64.
- Fix a potential overflow bug in the processor.
- Rebaseline the tests using smaller symbols.
- Fix microdump_writer_unittest.cc on 32-bit host.
BUG=chromium:410294
git-svn-id: http://google-breakpad.googlecode.com/svn/trunk@1407 4c0a9323-5329-0410-9bdc-e9ce6186880e
and updating minidump_stackwalk to show process uptime.
I tested this with a minidump from Chrome and I got a result that
is inline with what the Windows debugger is showing for that dump:
minidump_stackwalk output:
--------------------------
Process uptime: 601 seconds
WinDBG output:
--------------
Process Uptime: 0 days 0:10:01.000
I didn't update the machine readable output of minidump_stackwalk
on purpose in order to avoid breaking someone that uses it.
It can be added later to the machine output if needed.
R=mark@chromium.org
Review URL: https://breakpad.appspot.com/7754002
git-svn-id: http://google-breakpad.googlecode.com/svn/trunk@1406 4c0a9323-5329-0410-9bdc-e9ce6186880e
This introduces the microdump_stackwalk binary which takes advantage
of the MicrodumpProcessor to symbolize microdumps.
Its operation is identical to the one of minidump_stackwalk.
This CL, in fact, is also refactoring most of the common bits into
stackwalk_common.
BUG=chromium:410294
R=mmandlis@chromium.org
Review URL: https://breakpad.appspot.com/4704002
git-svn-id: http://google-breakpad.googlecode.com/svn/trunk@1405 4c0a9323-5329-0410-9bdc-e9ce6186880e
processing upcoming implementation.
dump_context.cc and dump_object.cc added in r/1370
microdump_processor.cc and microdump_processor_unittest.cc added in
r/1372
BUG=chromium:410294
git-svn-id: http://google-breakpad.googlecode.com/svn/trunk@1373 4c0a9323-5329-0410-9bdc-e9ce6186880e
Adds the interfaces for MicrodumpProcessor (very similar to
MinidumpProcessor) and corresponding unittest stubs.
These stubs are required for multi-side integration and to start
rolling the updated processor library into the dependent projects.
BUG=chromium:410294
git-svn-id: http://google-breakpad.googlecode.com/svn/trunk@1372 4c0a9323-5329-0410-9bdc-e9ce6186880e
This GYP-ifies the src/processor and src/common directories on those platforms
as well. The Makefile build uses much more granular unittest executables, so
the new processor_unittests does not yet link because of multiple main() symbols,
but this will be fixed later.
Update issue 575
R=mark@chromium.org
Review URL: https://breakpad.appspot.com/10674002
git-svn-id: http://google-breakpad.googlecode.com/svn/trunk@1358 4c0a9323-5329-0410-9bdc-e9ce6186880e
- Convert time_t values to UTC correctly. It is incorrect to cast a uint32_t*
to time_t* because the two types may have different widths. This is the
case on many 64-bit systems, where time_t is a 64-bit signed integer.
Conversion is unified in a single function, and additional uses of time_t
in minidump files not previously displayed in UTC are now displayed.
- Interpret the IMAGE_DEBUG_MISC structure correctly.
- When printing MINIDUMP_SYSTEM_INFO structures, always show the "x86" side
of the union, and state whether it's expected to be valid. (Existing
Breakpad-produced non-Windows minidumps for x86_64 use the "x86" side of
union, but Windows minidumps for x86_64 use the "other" side, so I want to
print both.)
R=ivanpe@chromium.org
Review URL: https://breakpad.appspot.com/5674002
git-svn-id: http://google-breakpad.googlecode.com/svn/trunk@1339 4c0a9323-5329-0410-9bdc-e9ce6186880e
.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
