//===-- 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 "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/FunctionCaller.h"
#include "lldb/Expression/UtilityFunction.h"
#include "lldb/Symbol/ClangASTContext.h"
#include "lldb/Symbol/Symbol.h"
#include "lldb/Target/ExecutionContext.h"
#include "lldb/Target/Process.h"
#include "lldb/Target/Target.h"
#include "lldb/Target/Thread.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_impl_code_up (),
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 CompilerType 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;
FunctionCaller *get_queues_caller = nullptr;
// Scope for mutex locker:
{
Mutex::Locker locker(m_get_queues_function_mutex);
// First stage is to make the ClangUtility to hold our injected function:
if (!m_get_queues_impl_code_up.get())
{
if (g_get_current_queues_function_code != NULL)
{
Error error;
m_get_queues_impl_code_up.reset (exe_ctx.GetTargetRef().GetUtilityFunctionForLanguage(g_get_current_queues_function_code,
eLanguageTypeC,
g_get_current_queues_function_name,
error));
if (error.Fail())
{
if (log)
log->Printf ("Failed to get UtilityFunction for queues introspection: %s.", error.AsCString());
return args_addr;
}
if (!m_get_queues_impl_code_up->Install(errors, exe_ctx))
{
if (log)
log->Printf ("Failed to install queues introspection: %s.", errors.GetData());
m_get_queues_impl_code_up.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;
}
}
// Next make the runner function for our implementation utility function.
ClangASTContext *clang_ast_context = thread.GetProcess()->GetTarget().GetScratchClangASTContext();
CompilerType get_queues_return_type = clang_ast_context->GetBasicType(eBasicTypeVoid).GetPointerType();
Error error;
get_queues_caller = m_get_queues_impl_code_up->MakeFunctionCaller (get_queues_return_type,
get_queues_arglist,
error);
if (error.Fail())
{
if (log)
log->Printf ("Could not get function caller for get-queues function: %s.", error.AsCString());
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 (!get_queues_caller->WriteFunctionArguments (exe_ctx, args_addr, 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.
CompilerType 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.SetCompilerType (clang_void_ptr_type);
CompilerType clang_int_type = clang_ast_context->GetBasicType(eBasicTypeInt);
Value debug_value;
debug_value.SetValueType (Value::eValueTypeScalar);
debug_value.SetCompilerType (clang_int_type);
Value page_to_free_value;
page_to_free_value.SetValueType (Value::eValueTypeScalar);
page_to_free_value.SetCompilerType (clang_void_ptr_type);
CompilerType 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.SetCompilerType (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_impl_code_up)
{
error.SetErrorString ("Unable to compile __introspection_dispatch_get_queues.");
return return_value;
}
FunctionCaller *get_queues_caller = m_get_queues_impl_code_up->GetFunctionCaller();
if (get_queues_caller == NULL)
{
error.SetErrorString ("Unable to get caller for call __introspection_dispatch_get_queues");
return return_value;
}
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 = get_queues_caller->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;
}
