From d394434a93a7dda8b6f1701327a2887d4892e3e6 Mon Sep 17 00:00:00 2001 From: "ivan.penkov@gmail.com" Date: Thu, 27 Jun 2013 20:34:30 +0000 Subject: This change is addressing a particularly nasty issue where the stackwalker doesn't see the correct thread stack memory. Instead, it loads garbage (from offset 0 of the minidump file - well that's not garbage, but it is not the stack memory region either) and attempts to walk it. A typical symptom of this issue is when you get a single stack frame after processing - the context frame - for which you don't need stack memory. This issue is caused by an invalid RVA in the memory descriptor stored inside the MINIDUMP_THREAD structure for the thread. Luckily, the invalid RVA is 0, and the start_of_memory_region appears to be correct, so this issue can be easily detected and the correct memory region can be loaded using an RVA specified in the MinidumpMemoryList. I couldn't find a reasonable description on MSDN regarding MINIDUMP_MEMORY_DESCRIPTOR.MINIDUMP_LOCATION_DESCRIPTOR having RVA of 0 except maybe for full dumps where the 64-bit version of the structure (MINIDUMP_MEMORY_DESCRIPTOR64) is used and it has no RVA at all. It has a 64-bit DataSize which if interpreted as the 32-bit structure will very likely result in 0 for the RVA: http://msdn.microsoft.com/en-us/library/windows/desktop/ms680384(v=vs.85).aspx Anyways, the dump that I looked at was not a full dump so 0 for RVA is a bit puzzling (at least easily detectable): ... Microsoft (R) Windows Debugger Version 6.2.9200.20512 X86 Copyright (c) Microsoft Corporation. All rights reserved. ... User Mini Dump File: Only registers, stack and portions of memory are available ... MINIDUMP_HEADER: Version A793 (62F0) NumberOfStreams 11 Flags 160 0020 MiniDumpWithUnloadedModules 0040 MiniDumpWithIndirectlyReferencedMemory 0100 MiniDumpWithProcessThreadData Review URL: https://breakpad.appspot.com/606002 git-svn-id: http://google-breakpad.googlecode.com/svn/trunk@1194 4c0a9323-5329-0410-9bdc-e9ce6186880e --- src/processor/minidump.cc | 14 ++++++++++++-- 1 file changed, 12 insertions(+), 2 deletions(-) (limited to 'src/processor/minidump.cc') diff --git a/src/processor/minidump.cc b/src/processor/minidump.cc index 4ad82053..7ad736d5 100755 --- a/src/processor/minidump.cc +++ b/src/processor/minidump.cc @@ -1509,13 +1509,15 @@ bool MinidumpThread::Read() { } // Check for base + size overflow or undersize. - if (thread_.stack.memory.data_size == 0 || + if (thread_.stack.memory.rva == 0 || + thread_.stack.memory.data_size == 0 || thread_.stack.memory.data_size > numeric_limits::max() - thread_.stack.start_of_memory_range) { // This is ok, but log an error anyway. BPLOG(ERROR) << "MinidumpThread has a memory region problem, " << HexString(thread_.stack.start_of_memory_range) << "+" << - HexString(thread_.stack.memory.data_size); + HexString(thread_.stack.memory.data_size) << + ", RVA 0x" << HexString(thread_.stack.memory.rva); } else { memory_ = new MinidumpMemoryRegion(minidump_); memory_->SetDescriptor(&thread_.stack); @@ -1525,6 +1527,14 @@ bool MinidumpThread::Read() { return true; } +uint64_t MinidumpThread::GetStartOfStackMemoryRange() const { + if (!valid_) { + BPLOG(ERROR) << "GetStartOfStackMemoryRange: Invalid MinidumpThread"; + return 0; + } + + return thread_.stack.start_of_memory_range; +} MinidumpMemoryRegion* MinidumpThread::GetMemory() { if (!valid_) { -- cgit v1.2.1