On 04/12/2017 06:33 PM, Jason Molenda via lldb-commits wrote:
Author: jmolenda
Date: Wed Apr 12 18:33:30 2017
New Revision: 300138
URL: http://llvm.org/viewvc/llvm-project?rev=300138&view=rev
Log:
Use two LC_NOTE load commands for identifying the main binary that
lldb should use when given a corefile.
This uses an LC_NOTE "main bin spec" or an LC_NOTE "kern ver str"
if they are present in a Mach-O core file.
Core files may have multiple different binaries -- different kernels,
or a mix of user process and kernel binaries -- and it can be
difficult for lldb to detect the correct one to use simply by looking
at the pages of memory. These two new LC_NOTE load commands allow
for the correct binary to be recorded unambiguously.
<rdar://problem/20878266>
Modified:
lldb/trunk/include/lldb/Symbol/ObjectFile.h
lldb/trunk/source/Plugins/ObjectFile/Mach-O/ObjectFileMachO.cpp
lldb/trunk/source/Plugins/ObjectFile/Mach-O/ObjectFileMachO.h
lldb/trunk/source/Plugins/Process/mach-core/ProcessMachCore.cpp
Modified: lldb/trunk/include/lldb/Symbol/ObjectFile.h
URL:
http://llvm.org/viewvc/llvm-project/lldb/trunk/include/lldb/Symbol/ObjectFile.h?rev=300138&r1=300137&r2=300138&view=diff
==============================================================================
--- lldb/trunk/include/lldb/Symbol/ObjectFile.h (original)
+++ lldb/trunk/include/lldb/Symbol/ObjectFile.h Wed Apr 12 18:33:30 2017
@@ -18,6 +18,7 @@
#include "lldb/Utility/DataExtractor.h"
#include "lldb/Utility/Endian.h"
#include "lldb/Utility/FileSpec.h"
+#include "lldb/Utility/UUID.h"
#include "lldb/lldb-private.h"
namespace lldb_private {
@@ -576,6 +577,32 @@ public:
return std::string();
}
+ //------------------------------------------------------------------
+ /// When the ObjectFile is a core file, lldb needs to locate the
+ /// "binary" in the core file. lldb can iterate over the pages looking
+ /// for a valid binary, but some core files may have metadata
+ /// describing where the main binary is exactly which removes ambiguity
+ /// when there are multiple binaries present in the captured memory pages.
+ ///
+ /// @param[out] address
+ /// If the address of the binary is specified, this will be set.
+ /// This is an address is the virtual address space of the core file
+ /// memory segments; it is not an offset into the object file.
+ /// If no address is available, will be set to LLDB_INVALID_ADDRESS.
+ ///
+ /// @param[out] uuid
+ /// If the uuid of the binary is specified, this will be set.
+ /// If no UUID is available, will be cleared.
+ ///
+ /// @return
+ /// Returns true if either address or uuid has been set.
+ //------------------------------------------------------------------
+ virtual bool GetCorefileMainBinaryInfo (lldb::addr_t &address, UUID &uuid) {
+ address = LLDB_INVALID_ADDRESS;
+ uuid.Clear();
+ return false;
+ }
+
virtual lldb::RegisterContextSP
GetThreadContextAtIndex(uint32_t idx, lldb_private::Thread &thread) {
return lldb::RegisterContextSP();
Modified: lldb/trunk/source/Plugins/ObjectFile/Mach-O/ObjectFileMachO.cpp
URL:
http://llvm.org/viewvc/llvm-project/lldb/trunk/source/Plugins/ObjectFile/Mach-O/ObjectFileMachO.cpp?rev=300138&r1=300137&r2=300138&view=diff
==============================================================================
--- lldb/trunk/source/Plugins/ObjectFile/Mach-O/ObjectFileMachO.cpp (original)
+++ lldb/trunk/source/Plugins/ObjectFile/Mach-O/ObjectFileMachO.cpp Wed Apr 12
18:33:30 2017
@@ -60,6 +60,8 @@
#ifndef __APPLE__
#include "Utility/UuidCompatibility.h"
+#else
+#include <uuid/uuid.h>
#endif
This doesn't build for me on Linux:
/src/llvm/tools/lldb/source/Plugins/ObjectFile/Mach-O/ObjectFileMachO.cpp:5471:39:
error: ‘uuid_clear’ was not declared in this scope
uuid_clear (raw_uuid);
^
There is a uuid_clear in my system uuid.h header, but on non-Apple
systems we seem to use ./source/Utility/UuidCompatibility.h, and there's
no uuid_clear in there.
-Hal
#define THUMB_ADDRESS_BIT_MASK 0xfffffffffffffffeull
@@ -5354,23 +5356,67 @@ uint32_t ObjectFileMachO::GetNumThreadCo
return m_thread_context_offsets.GetSize();
}
-// The LC_IDENT load command has been obsoleted for a very
-// long time and it should not occur in Mach-O files. But
-// if it is there, it may contain a hint about where to find
-// the main binary in a core file, so we'll use it.
std::string ObjectFileMachO::GetIdentifierString() {
std::string result;
ModuleSP module_sp(GetModule());
if (module_sp) {
std::lock_guard<std::recursive_mutex> guard(module_sp->GetMutex());
+
+ // First, look over the load commands for an LC_NOTE load command
+ // with data_owner string "kern ver str" & use that if found.
lldb::offset_t offset = MachHeaderSizeFromMagic(m_header.magic);
for (uint32_t i = 0; i < m_header.ncmds; ++i) {
const uint32_t cmd_offset = offset;
+ load_command lc;
+ if (m_data.GetU32(&offset, &lc.cmd, 2) == NULL)
+ break;
+ if (lc.cmd == LC_NOTE)
+ {
+ char data_owner[17];
+ m_data.CopyData (offset, 16, data_owner);
+ data_owner[16] = '\0';
+ offset += 16;
+ uint64_t fileoff = m_data.GetU64_unchecked (&offset);
+ uint64_t size = m_data.GetU64_unchecked (&offset);
+
+ // "kern ver str" has a uint32_t version and then a
+ // nul terminated c-string.
+ if (strcmp ("kern ver str", data_owner) == 0)
+ {
+ offset = fileoff;
+ uint32_t version;
+ if (m_data.GetU32 (&offset, &version, 1) != nullptr)
+ {
+ if (version == 1)
+ {
+ uint32_t strsize = size - sizeof (uint32_t);
+ char *buf = (char*) malloc (strsize);
+ if (buf)
+ {
+ m_data.CopyData (offset, strsize, buf);
+ buf[strsize - 1] = '\0';
+ result = buf;
+ if (buf)
+ free (buf);
+ return result;
+ }
+ }
+ }
+ }
+ }
+ offset = cmd_offset + lc.cmdsize;
+ }
+
+ // Second, make a pass over the load commands looking for an
+ // obsolete LC_IDENT load command.
+ offset = MachHeaderSizeFromMagic(m_header.magic);
+ for (uint32_t i = 0; i < m_header.ncmds; ++i) {
+ const uint32_t cmd_offset = offset;
struct ident_command ident_command;
if (m_data.GetU32(&offset, &ident_command, 2) == NULL)
break;
if (ident_command.cmd == LC_IDENT && ident_command.cmdsize != 0) {
- char *buf = (char *)malloc (ident_command.cmdsize);
+ char *buf = (char *) malloc (ident_command.cmdsize);
if (buf != nullptr
&& m_data.CopyData (offset, ident_command.cmdsize, buf) ==
ident_command.cmdsize) {
buf[ident_command.cmdsize - 1] = '\0';
@@ -5381,10 +5427,65 @@ std::string ObjectFileMachO::GetIdentifi
}
offset = cmd_offset + ident_command.cmdsize;
}
+
}
return result;
}
+bool ObjectFileMachO::GetCorefileMainBinaryInfo (addr_t &address, UUID &uuid) {
+ address = LLDB_INVALID_ADDRESS;
+ uuid.Clear();
+ ModuleSP module_sp(GetModule());
+ if (module_sp) {
+ std::lock_guard<std::recursive_mutex> guard(module_sp->GetMutex());
+ lldb::offset_t offset = MachHeaderSizeFromMagic(m_header.magic);
+ for (uint32_t i = 0; i < m_header.ncmds; ++i) {
+ const uint32_t cmd_offset = offset;
+ load_command lc;
+ if (m_data.GetU32(&offset, &lc.cmd, 2) == NULL)
+ break;
+ if (lc.cmd == LC_NOTE)
+ {
+ char data_owner[17];
+ memset (data_owner, 0, sizeof (data_owner));
+ m_data.CopyData (offset, 16, data_owner);
+ offset += 16;
+ uint64_t fileoff = m_data.GetU64_unchecked (&offset);
+ uint64_t size = m_data.GetU64_unchecked (&offset);
+
+ // "main bin spec" (main binary specification) data payload is
formatted:
+ // uint32_t version [currently 1]
+ // uint32_t type [0 == unspecified, 1 == kernel, 2 ==
user process]
+ // uint64_t address [ UINT64_MAX if address not specified ]
+ // uuid_t uuid [ all zero's if uuid not specified ]
+ // uint32_t log2_pagesize [ process page size in log base 2, e.g.
4k pages are 12. 0 for unspecified ]
+
+ if (strcmp ("main bin spec", data_owner) == 0 && size >= 32)
+ {
+ offset = fileoff;
+ uint32_t version;
+ if (m_data.GetU32 (&offset, &version, 1) != nullptr && version
== 1)
+ {
+ uint32_t type = 0;
+ uuid_t raw_uuid;
+ uuid_clear (raw_uuid);
+
+ if (m_data.GetU32 (&offset, &type, 1)
+ && m_data.GetU64 (&offset, &address, 1)
+ && m_data.CopyData (offset, sizeof (uuid_t), raw_uuid)
!= 0
+ && uuid.SetBytes (raw_uuid, sizeof (uuid_t)))
+ {
+ return true;
+ }
+ }
+ }
+ }
+ offset = cmd_offset + lc.cmdsize;
+ }
+ }
+ return false;
+}
+
lldb::RegisterContextSP
ObjectFileMachO::GetThreadContextAtIndex(uint32_t idx,
lldb_private::Thread &thread) {
Modified: lldb/trunk/source/Plugins/ObjectFile/Mach-O/ObjectFileMachO.h
URL:
http://llvm.org/viewvc/llvm-project/lldb/trunk/source/Plugins/ObjectFile/Mach-O/ObjectFileMachO.h?rev=300138&r1=300137&r2=300138&view=diff
==============================================================================
--- lldb/trunk/source/Plugins/ObjectFile/Mach-O/ObjectFileMachO.h (original)
+++ lldb/trunk/source/Plugins/ObjectFile/Mach-O/ObjectFileMachO.h Wed Apr 12
18:33:30 2017
@@ -20,6 +20,7 @@
#include "lldb/Symbol/ObjectFile.h"
#include "lldb/Utility/FileSpec.h"
#include "lldb/Utility/SafeMachO.h"
+#include "lldb/Utility/UUID.h"
//----------------------------------------------------------------------
// This class needs to be hidden as eventually belongs in a plugin that
@@ -113,6 +114,8 @@ public:
std::string GetIdentifierString() override;
+ bool GetCorefileMainBinaryInfo (lldb::addr_t &address, lldb_private::UUID &uuid) override;
+
lldb::RegisterContextSP
GetThreadContextAtIndex(uint32_t idx, lldb_private::Thread &thread)
override;
Modified: lldb/trunk/source/Plugins/Process/mach-core/ProcessMachCore.cpp
URL:
http://llvm.org/viewvc/llvm-project/lldb/trunk/source/Plugins/Process/mach-core/ProcessMachCore.cpp?rev=300138&r1=300137&r2=300138&view=diff
==============================================================================
--- lldb/trunk/source/Plugins/Process/mach-core/ProcessMachCore.cpp (original)
+++ lldb/trunk/source/Plugins/Process/mach-core/ProcessMachCore.cpp Wed Apr 12
18:33:30 2017
@@ -294,11 +294,26 @@ Error ProcessMachCore::DoLoadCore() {
bool found_main_binary_definitively = false;
+ addr_t objfile_binary_addr;
+ UUID objfile_binary_uuid;
+ if (core_objfile->GetCorefileMainBinaryInfo (objfile_binary_addr,
objfile_binary_uuid))
+ {
+ if (objfile_binary_addr != LLDB_INVALID_ADDRESS)
+ {
+ m_mach_kernel_addr = objfile_binary_addr;
+ found_main_binary_definitively = true;
+ if (log)
+ log->Printf ("ProcessMachCore::DoLoadCore: using kernel address
0x%" PRIx64
+ " from LC_NOTE 'main bin spec' load command.",
m_mach_kernel_addr);
+ }
+ }
+
// This checks for the presence of an LC_IDENT string in a core file;
// LC_IDENT is very obsolete and should not be used in new code, but
// if the load command is present, let's use the contents.
std::string corefile_identifier = core_objfile->GetIdentifierString();
- if (corefile_identifier.find("Darwin Kernel") != std::string::npos) {
+ if (found_main_binary_definitively == false
+ && corefile_identifier.find("Darwin Kernel") != std::string::npos) {
UUID uuid;
addr_t addr = LLDB_INVALID_ADDRESS;
if (corefile_identifier.find("UUID=") != std::string::npos) {
@@ -320,13 +335,13 @@ Error ProcessMachCore::DoLoadCore() {
found_main_binary_definitively = true;
if (log)
log->Printf("ProcessMachCore::DoLoadCore: Using the kernel address
0x%" PRIx64
- "from LC_IDENT string '%s'", addr,
corefile_identifier.c_str());
+ " from LC_IDENT/LC_NOTE 'kern ver str' string: '%s'",
addr, corefile_identifier.c_str());
}
}
- if (found_main_binary_definitively == false &&
- (m_dyld_addr == LLDB_INVALID_ADDRESS ||
- m_mach_kernel_addr == LLDB_INVALID_ADDRESS)) {
+ if (found_main_binary_definitively == false
+ && (m_dyld_addr == LLDB_INVALID_ADDRESS
+ || m_mach_kernel_addr == LLDB_INVALID_ADDRESS)) {
// We need to locate the main executable in the memory ranges
// we have in the core file. We need to search for both a user-process
dyld
// binary
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--
Hal Finkel
Lead, Compiler Technology and Programming Languages
Leadership Computing Facility
Argonne National Laboratory
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