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AppleGetThreadItemInfoHandler.cpp
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1//===-- AppleGetThreadItemInfoHandler.cpp ---------------------------------===//
2//
3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4// See https://llvm.org/LICENSE.txt for license information.
5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6//
7//===----------------------------------------------------------------------===//
8
10
12#include "lldb/Core/Module.h"
13#include "lldb/Core/Value.h"
18#include "lldb/Symbol/Symbol.h"
20#include "lldb/Target/Process.h"
22#include "lldb/Target/Target.h"
23#include "lldb/Target/Thread.h"
26#include "lldb/Utility/Log.h"
28#include "lldb/lldb-private.h"
29
30using namespace lldb;
31using namespace lldb_private;
32
33const char
35 "__lldb_backtrace_recording_get_thread_item_info";
36const char
38 " \n\
39extern \"C\" \n\
40{ \n\
41 /* \n\
42 * mach defines \n\
43 */ \n\
44 \n\
45 typedef unsigned int uint32_t; \n\
46 typedef unsigned long long uint64_t; \n\
47 typedef uint32_t mach_port_t; \n\
48 typedef mach_port_t vm_map_t; \n\
49 typedef int kern_return_t; \n\
50 typedef uint64_t mach_vm_address_t; \n\
51 typedef uint64_t mach_vm_size_t; \n\
52 \n\
53 mach_port_t mach_task_self (); \n\
54 kern_return_t mach_vm_deallocate (vm_map_t target, mach_vm_address_t address, mach_vm_size_t size); \n\
55 \n\
56 typedef void *pthread_t; \n\
57 extern int printf(const char *format, ...); \n\
58 extern pthread_t pthread_self(void); \n\
59 \n\
60 /* \n\
61 * libBacktraceRecording defines \n\
62 */ \n\
63 \n\
64 typedef uint32_t queue_list_scope_t; \n\
65 typedef void *dispatch_queue_t; \n\
66 typedef void *introspection_dispatch_queue_info_t; \n\
67 typedef void *introspection_dispatch_item_info_ref; \n\
68 \n\
69 extern void __introspection_dispatch_thread_get_item_info (uint64_t thread_id, \n\
70 introspection_dispatch_item_info_ref *returned_queues_buffer, \n\
71 uint64_t *returned_queues_buffer_size); \n\
72 \n\
73 /* \n\
74 * return type define \n\
75 */ \n\
76 \n\
77 struct get_thread_item_info_return_values \n\
78 { \n\
79 uint64_t item_info_buffer_ptr; /* the address of the items buffer from libBacktraceRecording */ \n\
80 uint64_t item_info_buffer_size; /* the size of the items buffer from libBacktraceRecording */ \n\
81 }; \n\
82 \n\
83 void __lldb_backtrace_recording_get_thread_item_info \n\
84 (struct get_thread_item_info_return_values *return_buffer, \n\
85 int debug, \n\
86 uint64_t thread_id, \n\
87 void *page_to_free, \n\
88 uint64_t page_to_free_size) \n\
89{ \n\
90 void *pthread_id = pthread_self (); \n\
91 if (debug) \n\
92 printf (\"entering get_thread_item_info with args return_buffer == %p, debug == %d, thread id == 0x%llx, page_to_free == %p, page_to_free_size == 0x%llx\\n\", return_buffer, debug, (uint64_t) thread_id, page_to_free, page_to_free_size); \n\
93 if (page_to_free != 0) \n\
94 { \n\
95 mach_vm_deallocate (mach_task_self(), (mach_vm_address_t) page_to_free, (mach_vm_size_t) page_to_free_size); \n\
96 } \n\
97 \n\
98 __introspection_dispatch_thread_get_item_info (thread_id, \n\
99 (void**)&return_buffer->item_info_buffer_ptr, \n\
100 &return_buffer->item_info_buffer_size); \n\
101} \n\
102} \n\
103";
104
106 : m_process(process), m_get_thread_item_info_impl_code(),
107 m_get_thread_item_info_function_mutex(),
108 m_get_thread_item_info_return_buffer_addr(LLDB_INVALID_ADDRESS),
109 m_get_thread_item_info_retbuffer_mutex() {}
110
112
114
115 if (m_process && m_process->IsAlive() &&
117 std::unique_lock<std::mutex> lock(m_get_thread_item_info_retbuffer_mutex,
118 std::defer_lock);
119 (void)lock.try_lock(); // Even if we don't get the lock, deallocate the buffer
121 }
122}
123
124// Compile our __lldb_backtrace_recording_get_thread_item_info() function (from
125// the source above in g_get_thread_item_info_function_code) if we don't find
126// that function in the inferior already with USE_BUILTIN_FUNCTION defined.
127// (e.g. this would be the case for testing.)
128//
129// Insert the __lldb_backtrace_recording_get_thread_item_info into the inferior
130// process if needed.
131//
132// Write the get_thread_item_info_arglist into the inferior's memory space to
133// prepare for the call.
134//
135// Returns the address of the arguments written down in the inferior process,
136// which can be used to make the function call.
137
139 Thread &thread, ValueList &get_thread_item_info_arglist) {
140 ThreadSP thread_sp(thread.shared_from_this());
141 ExecutionContext exe_ctx(thread_sp);
142 Address impl_code_address;
143 DiagnosticManager diagnostics;
146 FunctionCaller *get_thread_item_info_caller = nullptr;
147
148 // Scope for mutex locker:
149 {
150 std::lock_guard<std::mutex> guard(m_get_thread_item_info_function_mutex);
151
152 // First stage is to make the ClangUtility to hold our injected function:
153
157 auto utility_fn_or_error = exe_ctx.GetTargetRef().CreateUtilityFunction(
160 if (!utility_fn_or_error) {
161 LLDB_LOG_ERROR(log, utility_fn_or_error.takeError(),
162 "Failed to get UtilityFunction for "
163 "get-thread-item-info introspection: {0}.");
164 return args_addr;
165 }
166 m_get_thread_item_info_impl_code = std::move(*utility_fn_or_error);
167 } else {
168 LLDB_LOGF(log, "No get-thread-item-info introspection code found.");
170 }
171
172 // Also make the FunctionCaller for this UtilityFunction:
173
174 TypeSystemClangSP scratch_ts_sp = ScratchTypeSystemClang::GetForTarget(
175 thread.GetProcess()->GetTarget());
176 CompilerType get_thread_item_info_return_type =
177 scratch_ts_sp->GetBasicType(eBasicTypeVoid).GetPointerType();
178
179 get_thread_item_info_caller =
180 m_get_thread_item_info_impl_code->MakeFunctionCaller(
181 get_thread_item_info_return_type, get_thread_item_info_arglist,
182 thread_sp, error);
183 if (error.Fail() || get_thread_item_info_caller == nullptr) {
184 LLDB_LOGF(log,
185 "Failed to install get-thread-item-info introspection "
186 "caller: %s.",
187 error.AsCString());
189 return args_addr;
190 }
191
192 } else {
193 get_thread_item_info_caller =
194 m_get_thread_item_info_impl_code->GetFunctionCaller();
195 }
196 }
197
198 diagnostics.Clear();
199
200 // Now write down the argument values for this particular call. This looks
201 // like it might be a race condition if other threads were calling into here,
202 // but actually it isn't because we allocate a new args structure for this
203 // call by passing args_addr = LLDB_INVALID_ADDRESS...
204
205 if (!get_thread_item_info_caller->WriteFunctionArguments(
206 exe_ctx, args_addr, get_thread_item_info_arglist, diagnostics)) {
207 if (log) {
208 LLDB_LOGF(log, "Error writing get-thread-item-info function arguments");
209 diagnostics.Dump(log);
210 }
211 return args_addr;
212 }
213
214 return args_addr;
215}
216
219 tid_t thread_id,
220 addr_t page_to_free,
221 uint64_t page_to_free_size,
222 Status &error) {
223 lldb::StackFrameSP thread_cur_frame = thread.GetStackFrameAtIndex(0);
224 ProcessSP process_sp(thread.CalculateProcess());
225 TargetSP target_sp(thread.CalculateTarget());
226 TypeSystemClangSP scratch_ts_sp =
229
230 GetThreadItemInfoReturnInfo return_value;
232 return_value.item_buffer_size = 0;
233
234 error.Clear();
235
236 if (!thread.SafeToCallFunctions()) {
237 LLDB_LOGF(log, "Not safe to call functions on thread 0x%" PRIx64,
238 thread.GetID());
239 error.SetErrorString("Not safe to call functions on this thread.");
240 return return_value;
241 }
242
243 // Set up the arguments for a call to
244
245 // struct get_thread_item_info_return_values {
246 // uint64_t item_info_buffer_ptr; /* the address of the items buffer
247 // from libBacktraceRecording */
248 // uint64_t item_info_buffer_size; /* the size of the items buffer from
249 // libBacktraceRecording */
250 // };
251 //
252 // void __lldb_backtrace_recording_get_thread_item_info
253 // (struct
254 // get_thread_item_info_return_values
255 // *return_buffer,
256 // int debug,
257 // void *page_to_free,
258 // uint64_t page_to_free_size)
259
260 // Where the return_buffer argument points to a 24 byte region of memory
261 // already allocated by lldb in the inferior process.
262
263 CompilerType clang_void_ptr_type =
264 scratch_ts_sp->GetBasicType(eBasicTypeVoid).GetPointerType();
265 Value return_buffer_ptr_value;
266 return_buffer_ptr_value.SetValueType(Value::ValueType::Scalar);
267 return_buffer_ptr_value.SetCompilerType(clang_void_ptr_type);
268
269 CompilerType clang_int_type = scratch_ts_sp->GetBasicType(eBasicTypeInt);
270 Value debug_value;
272 debug_value.SetCompilerType(clang_int_type);
273
274 CompilerType clang_uint64_type =
275 scratch_ts_sp->GetBasicType(eBasicTypeUnsignedLongLong);
276 Value thread_id_value;
277 thread_id_value.SetValueType(Value::ValueType::Scalar);
278 thread_id_value.SetCompilerType(clang_uint64_type);
279
280 Value page_to_free_value;
281 page_to_free_value.SetValueType(Value::ValueType::Scalar);
282 page_to_free_value.SetCompilerType(clang_void_ptr_type);
283
284 Value page_to_free_size_value;
285 page_to_free_size_value.SetValueType(Value::ValueType::Scalar);
286 page_to_free_size_value.SetCompilerType(clang_uint64_type);
287
288 std::lock_guard<std::mutex> guard(m_get_thread_item_info_retbuffer_mutex);
290 addr_t bufaddr = process_sp->AllocateMemory(
291 32, ePermissionsReadable | ePermissionsWritable, error);
292 if (!error.Success() || bufaddr == LLDB_INVALID_ADDRESS) {
293 LLDB_LOGF(log, "Failed to allocate memory for return buffer for get "
294 "current queues func call");
295 return return_value;
296 }
298 }
299
300 ValueList argument_values;
301
302 return_buffer_ptr_value.GetScalar() =
304 argument_values.PushValue(return_buffer_ptr_value);
305
306 debug_value.GetScalar() = 0;
307 argument_values.PushValue(debug_value);
308
309 thread_id_value.GetScalar() = thread_id;
310 argument_values.PushValue(thread_id_value);
311
312 if (page_to_free != LLDB_INVALID_ADDRESS)
313 page_to_free_value.GetScalar() = page_to_free;
314 else
315 page_to_free_value.GetScalar() = 0;
316 argument_values.PushValue(page_to_free_value);
317
318 page_to_free_size_value.GetScalar() = page_to_free_size;
319 argument_values.PushValue(page_to_free_size_value);
320
321 addr_t args_addr = SetupGetThreadItemInfoFunction(thread, argument_values);
322
323 DiagnosticManager diagnostics;
324 ExecutionContext exe_ctx;
326 FunctionCaller *get_thread_item_info_caller = nullptr;
327
328 options.SetUnwindOnError(true);
329 options.SetIgnoreBreakpoints(true);
330 options.SetStopOthers(true);
331#if __has_feature(address_sanitizer)
332 options.SetTimeout(process_sp->GetUtilityExpressionTimeout());
333#else
334 options.SetTimeout(std::chrono::milliseconds(500));
335#endif
336 options.SetTryAllThreads(false);
337 options.SetIsForUtilityExpr(true);
338 thread.CalculateExecutionContext(exe_ctx);
339
341 error.SetErrorString("Unable to compile function to call "
342 "__introspection_dispatch_thread_get_item_info");
343 return return_value;
344 }
345
346 get_thread_item_info_caller =
347 m_get_thread_item_info_impl_code->GetFunctionCaller();
348
349 if (!get_thread_item_info_caller) {
350 error.SetErrorString("Unable to compile function caller for "
351 "__introspection_dispatch_thread_get_item_info");
352 return return_value;
353 }
354
355 ExpressionResults func_call_ret;
356 Value results;
357 func_call_ret = get_thread_item_info_caller->ExecuteFunction(
358 exe_ctx, &args_addr, options, diagnostics, results);
359 if (func_call_ret != eExpressionCompleted || !error.Success()) {
360 LLDB_LOGF(log,
361 "Unable to call "
362 "__introspection_dispatch_thread_get_item_info(), got "
363 "ExpressionResults %d, error contains %s",
364 func_call_ret, error.AsCString(""));
365 error.SetErrorString("Unable to call "
366 "__introspection_dispatch_thread_get_item_info() for "
367 "list of queues");
368 return return_value;
369 }
370
373 error);
374 if (!error.Success() ||
375 return_value.item_buffer_ptr == LLDB_INVALID_ADDRESS) {
377 return return_value;
378 }
379
382
383 if (!error.Success()) {
385 return return_value;
386 }
387
388 LLDB_LOGF(log,
389 "AppleGetThreadItemInfoHandler called "
390 "__introspection_dispatch_thread_get_item_info (page_to_free "
391 "== 0x%" PRIx64 ", size = %" PRId64
392 "), returned page is at 0x%" PRIx64 ", size %" PRId64,
393 page_to_free, page_to_free_size, return_value.item_buffer_ptr,
394 return_value.item_buffer_size);
395
396 return return_value;
397}
static llvm::raw_ostream & error(Stream &strm)
#define LLDB_LOGF(log,...)
Definition: Log.h:344
#define LLDB_LOG_ERROR(log, error,...)
Definition: Log.h:360
A section + offset based address class.
Definition: Address.h:59
GetThreadItemInfoReturnInfo GetThreadItemInfo(Thread &thread, lldb::tid_t thread_id, lldb::addr_t page_to_free, uint64_t page_to_free_size, lldb_private::Status &error)
Get the information about a work item by calling __introspection_dispatch_thread_get_item_info.
std::unique_ptr< UtilityFunction > m_get_thread_item_info_impl_code
lldb::addr_t SetupGetThreadItemInfoFunction(Thread &thread, ValueList &get_thread_item_info_arglist)
Generic representation of a type in a programming language.
Definition: CompilerType.h:36
CompilerType GetPointerType() const
Return a new CompilerType that is a pointer to this type.
void SetUnwindOnError(bool unwind=false)
Definition: Target.h:324
void SetTryAllThreads(bool try_others=true)
Definition: Target.h:357
void SetTimeout(const Timeout< std::micro > &timeout)
Definition: Target.h:345
void SetStopOthers(bool stop_others=true)
Definition: Target.h:361
void SetIgnoreBreakpoints(bool ignore=false)
Definition: Target.h:328
"lldb/Target/ExecutionContext.h" A class that contains an execution context.
Target & GetTargetRef() const
Returns a reference to the target object.
Encapsulates a function that can be called.
lldb::ExpressionResults ExecuteFunction(ExecutionContext &exe_ctx, lldb::addr_t *args_addr_ptr, const EvaluateExpressionOptions &options, DiagnosticManager &diagnostic_manager, Value &results)
Run the function this FunctionCaller was created with.
bool WriteFunctionArguments(ExecutionContext &exe_ctx, lldb::addr_t &args_addr_ref, DiagnosticManager &diagnostic_manager)
Insert the default function argument struct.
A plug-in interface definition class for debugging a process.
Definition: Process.h:342
uint64_t ReadUnsignedIntegerFromMemory(lldb::addr_t load_addr, size_t byte_size, uint64_t fail_value, Status &error)
Reads an unsigned integer of the specified byte size from process memory.
Definition: Process.cpp:2067
virtual bool IsAlive()
Check if a process is still alive.
Definition: Process.cpp:1086
Status DeallocateMemory(lldb::addr_t ptr)
The public interface to deallocating memory in the process.
Definition: Process.cpp:2338
static lldb::TypeSystemClangSP GetForTarget(Target &target, std::optional< IsolatedASTKind > ast_kind=DefaultAST, bool create_on_demand=true)
Returns the scratch TypeSystemClang for the given target.
An error handling class.
Definition: Status.h:44
llvm::Expected< std::unique_ptr< UtilityFunction > > CreateUtilityFunction(std::string expression, std::string name, lldb::LanguageType language, ExecutionContext &exe_ctx)
Creates and installs a UtilityFunction for the given language.
Definition: Target.cpp:2478
virtual lldb::StackFrameSP GetStackFrameAtIndex(uint32_t idx)
Definition: Thread.h:399
virtual bool SafeToCallFunctions()
Check whether this thread is safe to run functions.
Definition: Thread.cpp:1664
void CalculateExecutionContext(ExecutionContext &exe_ctx) override
Reconstruct the object's execution context into sc.
Definition: Thread.cpp:1420
lldb::ProcessSP CalculateProcess() override
Definition: Thread.cpp:1414
lldb::TargetSP CalculateTarget() override
Definition: Thread.cpp:1406
lldb::ProcessSP GetProcess() const
Definition: Thread.h:153
void PushValue(const Value &value)
Definition: Value.cpp:666
const Scalar & GetScalar() const
Definition: Value.h:112
@ Scalar
A raw scalar value.
void SetCompilerType(const CompilerType &compiler_type)
Definition: Value.cpp:252
void SetValueType(ValueType value_type)
Definition: Value.h:89
#define LLDB_INVALID_ADDRESS
Definition: lldb-defines.h:74
A class that represents a running process on the host machine.
Log * GetLog(Cat mask)
Retrieve the Log object for the channel associated with the given log enum.
Definition: Log.h:309
Definition: SBAddress.h:15
@ eBasicTypeUnsignedLongLong
@ eLanguageTypeC
Non-standardized C, such as K&R.
ExpressionResults
The results of expression evaluation.
@ eExpressionCompleted
uint64_t addr_t
Definition: lldb-types.h:83
uint64_t tid_t
Definition: lldb-types.h:86
lldb::user_id_t GetID() const
Get accessor for the user ID.
Definition: UserID.h:47