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clang-p2996/lldb/source/Plugins/SystemRuntime/MacOSX/AppleGetQueuesHandler.cpp
Jason Molenda b4892cd266 Add a new SBThread::SafeToCallFunctions API; this calls over to 
the SystemRuntime to check if a thread will have any problems 
performing an inferior function call so the driver can skip
making that function call on that thread.  Often the function
call can be executed on another thread instead.
<rdar://problem/16777874> 

llvm-svn: 208732
2014-05-13 22:02:48 +00:00

416 lines
21 KiB
C++
Raw Blame History

//===-- AppleGetQueuesHandler.cpp -------------------------------*- C++ -*-===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
#include "AppleGetQueuesHandler.h"
// C Includes
// C++ Includes
// Other libraries and framework includes
// Project includes
#include "AppleThreadPlanStepThroughObjCTrampoline.h"
#include "clang/AST/ASTContext.h"
#include "clang/AST/DeclCXX.h"
#include "lldb/Core/ConstString.h"
#include "lldb/Core/Log.h"
#include "lldb/Core/Module.h"
#include "lldb/Core/StreamString.h"
#include "lldb/Core/Value.h"
#include "lldb/Expression/ClangExpression.h"
#include "lldb/Expression/ClangFunction.h"
#include "lldb/Expression/ClangUtilityFunction.h"
#include "lldb/Symbol/ClangASTContext.h"
#include "lldb/Symbol/Symbol.h"
#include "lldb/Target/ExecutionContext.h"
#include "lldb/Target/Process.h"
using namespace lldb;
using namespace lldb_private;
const char *AppleGetQueuesHandler::g_get_current_queues_function_name = "__lldb_backtrace_recording_get_current_queues";
const char *AppleGetQueuesHandler::g_get_current_queues_function_code = " \n\
extern \"C\" \n\
{ \n\
/* \n\
* mach defines \n\
*/ \n\
\n\
typedef unsigned int uint32_t; \n\
typedef unsigned long long uint64_t; \n\
typedef uint32_t mach_port_t; \n\
typedef mach_port_t vm_map_t; \n\
typedef int kern_return_t; \n\
typedef uint64_t mach_vm_address_t; \n\
typedef uint64_t mach_vm_size_t; \n\
\n\
mach_port_t mach_task_self (); \n\
kern_return_t mach_vm_deallocate (vm_map_t target, mach_vm_address_t address, mach_vm_size_t size); \n\
\n\
/* \n\
* libBacktraceRecording defines \n\
*/ \n\
\n\
typedef uint32_t queue_list_scope_t; \n\
typedef void *introspection_dispatch_queue_info_t; \n\
\n\
extern uint64_t __introspection_dispatch_get_queues (queue_list_scope_t scope, \n\
introspection_dispatch_queue_info_t *returned_queues_buffer, \n\
uint64_t *returned_queues_buffer_size); \n\
extern int printf(const char *format, ...); \n\
\n\
/* \n\
* return type define \n\
*/ \n\
\n\
struct get_current_queues_return_values \n\
{ \n\
uint64_t queues_buffer_ptr; /* the address of the queues buffer from libBacktraceRecording */ \n\
uint64_t queues_buffer_size; /* the size of the queues buffer from libBacktraceRecording */ \n\
uint64_t count; /* the number of queues included in the queues buffer */ \n\
}; \n\
\n\
void __lldb_backtrace_recording_get_current_queues \n\
(struct get_current_queues_return_values *return_buffer, \n\
int debug, \n\
void *page_to_free, \n\
uint64_t page_to_free_size) \n\
{ \n\
if (debug) \n\
printf (\"entering get_current_queues with args %p, %d, 0x%p, 0x%llx\\n\", return_buffer, debug, page_to_free, page_to_free_size); \n\
if (page_to_free != 0) \n\
{ \n\
mach_vm_deallocate (mach_task_self(), (mach_vm_address_t) page_to_free, (mach_vm_size_t) page_to_free_size); \n\
} \n\
\n\
return_buffer->count = __introspection_dispatch_get_queues ( \n\
/* QUEUES_WITH_ANY_ITEMS */ 2, \n\
(void**)&return_buffer->queues_buffer_ptr, \n\
&return_buffer->queues_buffer_size); \n\
if (debug) \n\
printf(\"result was count %lld\\n\", return_buffer->count); \n\
} \n\
} \n\
";
AppleGetQueuesHandler::AppleGetQueuesHandler (Process *process) :
m_process (process),
m_get_queues_function (),
m_get_queues_impl_code (),
m_get_queues_function_mutex(),
m_get_queues_return_buffer_addr (LLDB_INVALID_ADDRESS),
m_get_queues_retbuffer_mutex()
{
}
AppleGetQueuesHandler::~AppleGetQueuesHandler ()
{
}
void
AppleGetQueuesHandler::Detach ()
{
if (m_process && m_process->IsAlive() && m_get_queues_return_buffer_addr != LLDB_INVALID_ADDRESS)
{
Mutex::Locker locker;
locker.TryLock (m_get_queues_retbuffer_mutex); // Even if we don't get the lock, deallocate the buffer
m_process->DeallocateMemory (m_get_queues_return_buffer_addr);
}
}
// Construct a ClangASTType for the structure that g_get_current_queues_function_code will return by value
// so we can extract the fields after performing the function call.
// i.e. we are getting this struct returned to us:
//
// struct get_current_queues_return_values
// {
// introspection_dispatch_queue_info_t *queues_buffer;
// uint64_t queues_buffer_size;
// uint64_t count;
// };
// Compile our __lldb_backtrace_recording_get_current_queues() function (from the
// source above in g_get_current_queues_function_code) if we don't find that function in the inferior
// already with USE_BUILTIN_FUNCTION defined. (e.g. this would be the case for testing.)
//
// Insert the __lldb_backtrace_recording_get_current_queues into the inferior process if needed.
//
// Write the get_queues_arglist into the inferior's memory space to prepare for the call.
//
// Returns the address of the arguments written down in the inferior process, which can be used to
// make the function call.
lldb::addr_t
AppleGetQueuesHandler::SetupGetQueuesFunction (Thread &thread, ValueList &get_queues_arglist)
{
ExecutionContext exe_ctx (thread.shared_from_this());
Address impl_code_address;
StreamString errors;
Log *log(lldb_private::GetLogIfAllCategoriesSet (LIBLLDB_LOG_SYSTEM_RUNTIME));
lldb::addr_t args_addr = LLDB_INVALID_ADDRESS;
// Scope for mutex locker:
{
Mutex::Locker locker(m_get_queues_function_mutex);
// First stage is to make the ClangUtility to hold our injected function:
#define USE_BUILTIN_FUNCTION 0 // Define this to 1 and we will use the get_implementation function found in the target.
// This is useful for debugging additions to the get_impl function 'cause you don't have
// to bother with string-ifying the code into g_get_current_queues_function_code.
if (USE_BUILTIN_FUNCTION)
{
ConstString our_utility_function_name("__lldb_backtrace_recording_get_current_queues");
SymbolContextList sc_list;
exe_ctx.GetTargetRef().GetImages().FindSymbolsWithNameAndType (our_utility_function_name, eSymbolTypeCode, sc_list);
if (sc_list.GetSize() == 1)
{
SymbolContext sc;
sc_list.GetContextAtIndex(0, sc);
if (sc.symbol != NULL)
impl_code_address = sc.symbol->GetAddress();
//lldb::addr_t addr = impl_code_address.GetOpcodeLoadAddress (exe_ctx.GetTargetPtr());
//printf ("Getting address for our_utility_function: 0x%" PRIx64 ".\n", addr);
}
else
{
//printf ("Could not find queues introspection function address.\n");
return args_addr;
}
}
else if (!m_get_queues_impl_code.get())
{
if (g_get_current_queues_function_code != NULL)
{
m_get_queues_impl_code.reset (new ClangUtilityFunction (g_get_current_queues_function_code,
g_get_current_queues_function_name));
if (!m_get_queues_impl_code->Install(errors, exe_ctx))
{
if (log)
log->Printf ("Failed to install queues introspection: %s.", errors.GetData());
m_get_queues_impl_code.reset();
return args_addr;
}
}
else
{
if (log)
log->Printf("No queues introspection code found.");
errors.Printf ("No queues introspection code found.");
return LLDB_INVALID_ADDRESS;
}
impl_code_address.Clear();
impl_code_address.SetOffset(m_get_queues_impl_code->StartAddress());
}
else
{
impl_code_address.Clear();
impl_code_address.SetOffset(m_get_queues_impl_code->StartAddress());
}
// Next make the runner function for our implementation utility function.
if (!m_get_queues_function.get())
{
ClangASTContext *clang_ast_context = thread.GetProcess()->GetTarget().GetScratchClangASTContext();
ClangASTType get_queues_return_type = clang_ast_context->GetBasicType(eBasicTypeVoid).GetPointerType();
m_get_queues_function.reset(new ClangFunction (thread,
get_queues_return_type,
impl_code_address,
get_queues_arglist,
"queue-fetch-queues"));
errors.Clear();
unsigned num_errors = m_get_queues_function->CompileFunction(errors);
if (num_errors)
{
if (log)
log->Printf ("Error compiling get-queues function: \"%s\".", errors.GetData());
return args_addr;
}
errors.Clear();
if (!m_get_queues_function->WriteFunctionWrapper(exe_ctx, errors))
{
if (log)
log->Printf ("Error Inserting get-queues function: \"%s\".", errors.GetData());
return args_addr;
}
}
}
errors.Clear();
// Now write down the argument values for this particular call. This looks like it might be a race condition
// if other threads were calling into here, but actually it isn't because we allocate a new args structure for
// this call by passing args_addr = LLDB_INVALID_ADDRESS...
if (!m_get_queues_function->WriteFunctionArguments (exe_ctx, args_addr, impl_code_address, get_queues_arglist, errors))
{
if (log)
log->Printf ("Error writing get-queues function arguments: \"%s\".", errors.GetData());
return args_addr;
}
return args_addr;
}
AppleGetQueuesHandler::GetQueuesReturnInfo
AppleGetQueuesHandler::GetCurrentQueues (Thread &thread, addr_t page_to_free, uint64_t page_to_free_size, Error &error)
{
lldb::StackFrameSP thread_cur_frame = thread.GetStackFrameAtIndex(0);
ProcessSP process_sp (thread.CalculateProcess());
TargetSP target_sp (thread.CalculateTarget());
ClangASTContext *clang_ast_context = target_sp->GetScratchClangASTContext();
Log *log(lldb_private::GetLogIfAllCategoriesSet (LIBLLDB_LOG_SYSTEM_RUNTIME));
GetQueuesReturnInfo return_value;
return_value.queues_buffer_ptr = LLDB_INVALID_ADDRESS;
return_value.queues_buffer_size = 0;
return_value.count = 0;
error.Clear();
if (thread.SafeToCallFunctions() == false)
{
if (log)
log->Printf ("Not safe to call functions on thread 0x%" PRIx64, thread.GetID());
error.SetErrorString ("Not safe to call functions on this thread.");
return return_value;
}
// Set up the arguments for a call to
// struct get_current_queues_return_values
// {
// uint64_t queues_buffer_ptr; /* the address of the queues buffer from libBacktraceRecording */
// uint64_t queues_buffer_size; /* the size of the queues buffer from libBacktraceRecording */
// uint64_t count; /* the number of queues included in the queues buffer */
// };
//
// void
// __lldb_backtrace_recording_get_current_queues
// (struct get_current_queues_return_values *return_buffer,
// void *page_to_free,
// uint64_t page_to_free_size);
// Where the return_buffer argument points to a 24 byte region of memory already allocated by lldb in
// the inferior process.
ClangASTType clang_void_ptr_type = clang_ast_context->GetBasicType(eBasicTypeVoid).GetPointerType();
Value return_buffer_ptr_value;
return_buffer_ptr_value.SetValueType (Value::eValueTypeScalar);
return_buffer_ptr_value.SetClangType (clang_void_ptr_type);
ClangASTType clang_int_type = clang_ast_context->GetBasicType(eBasicTypeInt);
Value debug_value;
debug_value.SetValueType (Value::eValueTypeScalar);
debug_value.SetClangType (clang_int_type);
Value page_to_free_value;
page_to_free_value.SetValueType (Value::eValueTypeScalar);
page_to_free_value.SetClangType (clang_void_ptr_type);
ClangASTType clang_uint64_type = clang_ast_context->GetBasicType(eBasicTypeUnsignedLongLong);
Value page_to_free_size_value;
page_to_free_size_value.SetValueType (Value::eValueTypeScalar);
page_to_free_size_value.SetClangType (clang_uint64_type);
Mutex::Locker locker(m_get_queues_retbuffer_mutex);
if (m_get_queues_return_buffer_addr == LLDB_INVALID_ADDRESS)
{
addr_t bufaddr = process_sp->AllocateMemory (32, ePermissionsReadable | ePermissionsWritable, error);
if (!error.Success() || bufaddr == LLDB_INVALID_ADDRESS)
{
if (log)
log->Printf ("Failed to allocate memory for return buffer for get current queues func call");
return return_value;
}
m_get_queues_return_buffer_addr = bufaddr;
}
ValueList argument_values;
return_buffer_ptr_value.GetScalar() = m_get_queues_return_buffer_addr;
argument_values.PushValue (return_buffer_ptr_value);
debug_value.GetScalar() = 0;
argument_values.PushValue (debug_value);
if (page_to_free != LLDB_INVALID_ADDRESS)
page_to_free_value.GetScalar() = page_to_free;
else
page_to_free_value.GetScalar() = 0;
argument_values.PushValue (page_to_free_value);
page_to_free_size_value.GetScalar() = page_to_free_size;
argument_values.PushValue (page_to_free_size_value);
addr_t args_addr = SetupGetQueuesFunction (thread, argument_values);
if (m_get_queues_function == NULL)
{
error.SetErrorString ("Unable to compile function to call __introspection_dispatch_get_queues");
}
StreamString errors;
ExecutionContext exe_ctx;
EvaluateExpressionOptions options;
options.SetUnwindOnError (true);
options.SetIgnoreBreakpoints (true);
options.SetStopOthers (true);
options.SetTimeoutUsec(500000);
options.SetTryAllThreads (false);
thread.CalculateExecutionContext (exe_ctx);
ExpressionResults func_call_ret;
Value results;
func_call_ret = m_get_queues_function->ExecuteFunction (exe_ctx, &args_addr, options, errors, results);
if (func_call_ret != eExpressionCompleted || !error.Success())
{
if (log)
log->Printf ("Unable to call introspection_get_dispatch_queues(), got ExpressionResults %d, error contains %s", func_call_ret, error.AsCString(""));
error.SetErrorString ("Unable to call introspection_get_dispatch_queues() for list of queues");
return return_value;
}
return_value.queues_buffer_ptr = m_process->ReadUnsignedIntegerFromMemory (m_get_queues_return_buffer_addr, 8, LLDB_INVALID_ADDRESS, error);
if (!error.Success() || return_value.queues_buffer_ptr == LLDB_INVALID_ADDRESS)
{
return_value.queues_buffer_ptr = LLDB_INVALID_ADDRESS;
return return_value;
}
return_value.queues_buffer_size = m_process->ReadUnsignedIntegerFromMemory (m_get_queues_return_buffer_addr + 8, 8, 0, error);
if (!error.Success())
{
return_value.queues_buffer_ptr = LLDB_INVALID_ADDRESS;
return return_value;
}
return_value.count = m_process->ReadUnsignedIntegerFromMemory (m_get_queues_return_buffer_addr + 16, 8, 0, error);
if (!error.Success())
{
return_value.queues_buffer_ptr = LLDB_INVALID_ADDRESS;
return return_value;
}
if (log)
log->Printf ("AppleGetQueuesHandler called __introspection_dispatch_get_queues (page_to_free == 0x%" PRIx64 ", size = %" PRId64 "), returned page is at 0x%" PRIx64 ", size %" PRId64 ", count = %" PRId64, page_to_free, page_to_free_size, return_value.queues_buffer_ptr, return_value.queues_buffer_size, return_value.count);
return return_value;
}
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