I haven't been able to reproduce this locally, but we see errors in
crash dumps where the unloaded module list consists of a number of
modules with invalid names and implausible addresses. My assumption is
that RTL_UNLOAD_EVENT_TRACE isn't correct for some OS levels. Instead of
trying to finesse and test that, use RtlGetUnloadEventTraceEx() instead
of RtlGetUnloadEventTrace(), which returns an element size. (This
function is Vista+ which is why it wasn't used the first time around.)
R=mark@chromium.org
BUG=chromium:620175
Change-Id: I4d7080a03623276f9c1c038d6e7329af70e4a64c
Reviewed-on: https://chromium-review.googlesource.com/421564
Reviewed-by: Mark Mentovai <mark@chromium.org>
The limit was being reset per-thread, which isn't how it was intended or
documented. Add test to confirm the limit is more-or-less respected.
R=mark@chromium.org
BUG=crashpad:111
Change-Id: Ifae9f1ce2afcc2d6c6832db46f9b5c36adb35b42
Reviewed-on: https://chromium-review.googlesource.com/346131
Reviewed-by: Mark Mentovai <mark@chromium.org>
Because DumpAndCrashTargetProcess() suspends the process, the thread
suspend count is one too high for all threads other than the injection
one in the thread snapshots. Compensate for this when we detect this
type of exception.
BUG=crashpad:103
Change-Id: Ib77112fddf5324fc0e43f598604e56f77d67ff54
Reviewed-on: https://chromium-review.googlesource.com/340372
Reviewed-by: Mark Mentovai <mark@chromium.org>
Adds a new client API which allows causing an exception in another
process. This is accomplished by injecting a thread that calls
RaiseException(). A special exception code is used that indicates to the
handler that the exception arguments contain a thread id and exception
code, which are in turn used to fabricate an exception record. This is
so that the API can allow the client to "blame" a particular thread in
the target process.
The target process must also be a registered Crashpad client, as the
normal exception mechanism is used to handle the exception.
The injection of a thread is used instead of DebugBreakProcess() which
does not cause the UnhandledExceptionFilter() to be executed.
NtCreateThreadEx() is used in lieu of CreateRemoteThread() as it allows
passing of a flag which avoids calling DllMain()s. This is necessary to
allow thread creation to succeed even when the target process is
deadlocked on the loader lock.
BUG=crashpad:103
Change-Id: I797007bd2b1e3416afe3f37a6566c0cdb259b106
Reviewed-on: https://chromium-review.googlesource.com/339263
Reviewed-by: Mark Mentovai <mark@chromium.org>
Add a user-configurable cap on the amount of memory that is gathered by
dereferencing thread stacks. (SyzyAsan stores a tremendously large
number of pointers on the stack, so the dumps were ending up in the ~25M
range.)
Also reduce the range around pointers somewhat.
Change-Id: I6bce57d86bd2f6a796e1580c530909e089ec00ed
Reviewed-on: https://chromium-review.googlesource.com/338463
Reviewed-by: Mark Mentovai <mark@chromium.org>
On Win 7 in a debug configuration, walking all locks was gathering
hundreds of thousands of locks, causing test timeouts to be exceeded in
debug. On user machines, UnhandledExceptionHandler() could have timed
out too. For now, only grab the loader lock as it's the most interesting
one. Unfortunately, this means that !locks won't work for now.
In the future, we may want to figure out a signalling mechanism so that
the client can note other interesting locks to be grabbed, and just
avoid walking the list entirely.
R=mark@chromium.org
BUG=chromium:546288
Review URL: https://codereview.chromium.org/1475033005 .
This reverts commit b3464d96f5fc0d82f860651b7918626dfbd80d65.
It was temporarily landed to be able to run as the DEPS version in Chrome.
BUG=
Review URL: https://codereview.chromium.org/1474223002 .
On Win 7 in a debug configuration, this was gathering hundreds of
thousands of locks, causing test timeouts to be exceeded. On user
machines, UnhandledExceptionHandler() probably would have timed out
also. Arbitrarily cap the number of locks captured, as we don't have a
pressing need for anything other than the LoaderLock anyway.
In the future, we may want to figure out a signalling mechanism so that
the client can note other interesting locks to be grabbed, and just
avoid walking the list entirely.
R=mark@chromium.org
BUG=chromium:546288
Review URL: https://codereview.chromium.org/1475033005 .
Capture the memory for the loader lock (can be inspected by !cs), as
well as all locks that were created with .DebugInfo which can be viewed
with !locks.
e.g.
0:000> !cs ntdll!LdrpLoaderLock
-----------------------------------------
Critical section = 0x778d6410 (ntdll!LdrpLoaderLock+0x0)
DebugInfo = 0x778d6b6c
NOT LOCKED
LockSemaphore = 0x0
SpinCount = 0x04000000
0:000> !locks -v
CritSec ntdll!RtlpProcessHeapsListLock+0 at 778d7620
LockCount NOT LOCKED
RecursionCount 0
OwningThread 0
EntryCount 0
ContentionCount 0
CritSec +7a0248 at 007a0248
LockCount NOT LOCKED
RecursionCount 0
OwningThread 0
EntryCount 0
ContentionCount 0
CritSec crashy_program!g_critical_section_with_debug_info+0 at 01342c48
LockCount NOT LOCKED
RecursionCount 0
OwningThread 0
EntryCount 0
ContentionCount 0
CritSec crashy_program!crashpad::`anonymous namespace'::g_test_critical_section+0 at 01342be0
WaiterWoken No
LockCount 0
RecursionCount 1
OwningThread 34b8
EntryCount 0
ContentionCount 0
*** Locked
Scanned 4 critical sections
R=mark@chromium.org
BUG=crashpad:52
Review URL: https://codereview.chromium.org/1392093003 .
This makes the basics of !peb work in windbg, however, pointed-to things
are not yet retrieved. For full functionality, a variety of pointers in
the PEB also needs to be walked and captured.
e.g.
Previously:
0:000> .ecxr
eax=00000007 ebx=7e383000 ecx=c3f9a943 edx=00000000 esi=006d62d0 edi=003c9280
eip=00384828 esp=005bf634 ebp=005bf638 iopl=0 nv up ei pl zr na pe nc
cs=0023 ss=002b ds=002b es=002b fs=0053 gs=002b efl=00010246
crashy_program!crashpad::`anonymous namespace'::SomeCrashyFunction+0x28:
00384828 c7002a000000 mov dword ptr [eax],2Ah ds:002b:00000007=????????
0:000> !peb
PEB at 7e383000
error 1 InitTypeRead( nt!_PEB at 7e383000)...
Now:
0:000> .ecxr
eax=00000007 ebx=7f958000 ecx=02102f4d edx=00000000 esi=00e162d0 edi=01389280
eip=01344828 esp=00c2fb64 ebp=00c2fb68 iopl=0 nv up ei pl zr na pe nc
cs=0023 ss=002b ds=002b es=002b fs=0053 gs=002b efl=00010246
crashy_program!crashpad::`anonymous namespace'::SomeCrashyFunction+0x28:
01344828 c7002a000000 mov dword ptr [eax],2Ah ds:002b:00000007=????????
0:000> !peb
PEB at 7f958000
InheritedAddressSpace: No
ReadImageFileExecOptions: No
BeingDebugged: No
ImageBaseAddress: 01340000
Ldr 77ec8b40
*** unable to read Ldr table at 77ec8b40
SubSystemData: 00000000
ProcessHeap: 00e10000
ProcessParameters: 00e114e0
CurrentDirectory: '< Name not readable >'
WindowTitle: '< Name not readable >'
ImageFile: '< Name not readable >'
CommandLine: '< Name not readable >'
DllPath: '< Name not readable >'
Environment: 00000000
Unable to read Environment string.
R=mark@chromium.org
BUG=crashpad:46
Review URL: https://codereview.chromium.org/1364053002 .
The next big piece of functionality in snapshot. There's a bit more
grubbing around in the NT internals than would be nice, and it has
made me start to question the value avoiding MinidumpWriteDump. But
this seems to extract most of the data we need (I haven't pulled
the cpu context yet, but I hope that won't be too hard.)
R=mark@chromium.org
BUG=crashpad:1
Review URL: https://codereview.chromium.org/1131473005
The main goal was to get the beginnings of module iteration and retrieval
of CrashpadInfo in snapshot. The main change for that is to move
crashpad_info_client_options[_test] down out of mac/.
This also requires adding some of the supporting code of snapshot in
ProcessReaderWin, ProcessSnapshotWin, and ModuleSnapshotWin. These are
partially copied from Mac or stubbed out with lots of TODO annotations.
This is a bit unfortunate, but seemed like the most productive way to
make progress incrementally. That is, it's mostly placeholder at the
moment, but hopefully has the right shape for things to come.
R=mark@chromium.org
BUG=crashpad:1
Review URL: https://codereview.chromium.org/1052813002
