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/google_breakpad/processor/minidump.h | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-) (limited to 'src/google_breakpad') diff --git a/src/google_breakpad/processor/minidump.h b/src/google_breakpad/processor/minidump.h index 8b2d0fe8..16b9d856 100644 --- a/src/google_breakpad/processor/minidump.h +++ b/src/google_breakpad/processor/minidump.h @@ -326,6 +326,11 @@ class MinidumpThread : public MinidumpObject { // Print a human-readable representation of the object to stdout. void Print(); + // Returns the start address of the thread stack memory region. Returns 0 if + // MinidumpThread is invalid. Note that this method can be called even when + // the thread memory cannot be read and GetMemory returns NULL. + virtual uint64_t GetStartOfStackMemoryRange() const; + protected: explicit MinidumpThread(Minidump* minidump); @@ -586,13 +591,14 @@ class MinidumpMemoryList : public MinidumpStream { // Random access to memory regions. Returns the region encompassing // the address identified by address. - MinidumpMemoryRegion* GetMemoryRegionForAddress(uint64_t address); + virtual MinidumpMemoryRegion* GetMemoryRegionForAddress(uint64_t address); // Print a human-readable representation of the object to stdout. void Print(); private: friend class Minidump; + friend class MockMinidumpMemoryList; typedef vector MemoryDescriptors; typedef vector MemoryRegions; @@ -932,7 +938,7 @@ class Minidump { // parameter). virtual MinidumpThreadList* GetThreadList(); MinidumpModuleList* GetModuleList(); - MinidumpMemoryList* GetMemoryList(); + virtual MinidumpMemoryList* GetMemoryList(); MinidumpException* GetException(); MinidumpAssertion* GetAssertion(); virtual MinidumpSystemInfo* GetSystemInfo(); -- cgit v1.2.1