1 | //===-- AppleGetQueuesHandler.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 | |
9 | #include "AppleGetQueuesHandler.h" |
10 | |
11 | #include "Plugins/TypeSystem/Clang/TypeSystemClang.h" |
12 | #include "lldb/Core/Module.h" |
13 | #include "lldb/Core/Value.h" |
14 | #include "lldb/Expression/DiagnosticManager.h" |
15 | #include "lldb/Expression/FunctionCaller.h" |
16 | #include "lldb/Expression/UtilityFunction.h" |
17 | #include "lldb/Symbol/Symbol.h" |
18 | #include "lldb/Target/ExecutionContext.h" |
19 | #include "lldb/Target/Process.h" |
20 | #include "lldb/Target/Target.h" |
21 | #include "lldb/Target/Thread.h" |
22 | #include "lldb/Utility/ConstString.h" |
23 | #include "lldb/Utility/LLDBLog.h" |
24 | #include "lldb/Utility/Log.h" |
25 | #include "lldb/Utility/StreamString.h" |
26 | |
27 | using namespace lldb; |
28 | using namespace lldb_private; |
29 | |
30 | const char *AppleGetQueuesHandler::g_get_current_queues_function_name = |
31 | "__lldb_backtrace_recording_get_current_queues" ; |
32 | const char *AppleGetQueuesHandler::g_get_current_queues_function_code = |
33 | " \n\ |
34 | extern \"C\" \n\ |
35 | { \n\ |
36 | /* \n\ |
37 | * mach defines \n\ |
38 | */ \n\ |
39 | \n\ |
40 | typedef unsigned int uint32_t; \n\ |
41 | typedef unsigned long long uint64_t; \n\ |
42 | typedef uint32_t mach_port_t; \n\ |
43 | typedef mach_port_t vm_map_t; \n\ |
44 | typedef int kern_return_t; \n\ |
45 | typedef uint64_t mach_vm_address_t; \n\ |
46 | typedef uint64_t mach_vm_size_t; \n\ |
47 | \n\ |
48 | mach_port_t mach_task_self (); \n\ |
49 | kern_return_t mach_vm_deallocate (vm_map_t target, mach_vm_address_t address, mach_vm_size_t size); \n\ |
50 | \n\ |
51 | /* \n\ |
52 | * libBacktraceRecording defines \n\ |
53 | */ \n\ |
54 | \n\ |
55 | typedef uint32_t queue_list_scope_t; \n\ |
56 | typedef void *introspection_dispatch_queue_info_t; \n\ |
57 | \n\ |
58 | extern uint64_t __introspection_dispatch_get_queues (queue_list_scope_t scope, \n\ |
59 | introspection_dispatch_queue_info_t *returned_queues_buffer, \n\ |
60 | uint64_t *returned_queues_buffer_size); \n\ |
61 | extern int printf(const char *format, ...); \n\ |
62 | \n\ |
63 | /* \n\ |
64 | * return type define \n\ |
65 | */ \n\ |
66 | \n\ |
67 | struct get_current_queues_return_values \n\ |
68 | { \n\ |
69 | uint64_t queues_buffer_ptr; /* the address of the queues buffer from libBacktraceRecording */ \n\ |
70 | uint64_t queues_buffer_size; /* the size of the queues buffer from libBacktraceRecording */ \n\ |
71 | uint64_t count; /* the number of queues included in the queues buffer */ \n\ |
72 | }; \n\ |
73 | \n\ |
74 | void __lldb_backtrace_recording_get_current_queues \n\ |
75 | (struct get_current_queues_return_values *return_buffer, \n\ |
76 | int debug, \n\ |
77 | void *page_to_free, \n\ |
78 | uint64_t page_to_free_size) \n\ |
79 | { \n\ |
80 | if (debug) \n\ |
81 | 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\ |
82 | if (page_to_free != 0) \n\ |
83 | { \n\ |
84 | mach_vm_deallocate (mach_task_self(), (mach_vm_address_t) page_to_free, (mach_vm_size_t) page_to_free_size); \n\ |
85 | } \n\ |
86 | \n\ |
87 | return_buffer->count = __introspection_dispatch_get_queues ( \n\ |
88 | /* QUEUES_WITH_ANY_ITEMS */ 2, \n\ |
89 | (void**)&return_buffer->queues_buffer_ptr, \n\ |
90 | &return_buffer->queues_buffer_size); \n\ |
91 | if (debug) \n\ |
92 | printf(\"result was count %lld\\n\", return_buffer->count); \n\ |
93 | } \n\ |
94 | } \n\ |
95 | " ; |
96 | |
97 | AppleGetQueuesHandler::AppleGetQueuesHandler(Process *process) |
98 | : m_process(process), m_get_queues_impl_code_up(), |
99 | m_get_queues_function_mutex(), |
100 | m_get_queues_return_buffer_addr(LLDB_INVALID_ADDRESS), |
101 | m_get_queues_retbuffer_mutex() {} |
102 | |
103 | AppleGetQueuesHandler::~AppleGetQueuesHandler() = default; |
104 | |
105 | void AppleGetQueuesHandler::Detach() { |
106 | |
107 | if (m_process && m_process->IsAlive() && |
108 | m_get_queues_return_buffer_addr != LLDB_INVALID_ADDRESS) { |
109 | std::unique_lock<std::mutex> lock(m_get_queues_retbuffer_mutex, |
110 | std::defer_lock); |
111 | (void)lock.try_lock(); // Even if we don't get the lock, deallocate the buffer |
112 | m_process->DeallocateMemory(ptr: m_get_queues_return_buffer_addr); |
113 | } |
114 | } |
115 | |
116 | // Construct a CompilerType for the structure that |
117 | // g_get_current_queues_function_code will return by value so we can extract |
118 | // the fields after performing the function call. i.e. we are getting this |
119 | // struct returned to us: |
120 | // |
121 | // struct get_current_queues_return_values |
122 | // { |
123 | // introspection_dispatch_queue_info_t *queues_buffer; |
124 | // uint64_t queues_buffer_size; |
125 | // uint64_t count; |
126 | // }; |
127 | |
128 | // Compile our __lldb_backtrace_recording_get_current_queues() function (from |
129 | // the source above in g_get_current_queues_function_code) if we don't find |
130 | // that function in the inferior already with USE_BUILTIN_FUNCTION defined. |
131 | // (e.g. this would be the case for testing.) |
132 | // |
133 | // Insert the __lldb_backtrace_recording_get_current_queues into the inferior |
134 | // process if needed. |
135 | // |
136 | // Write the get_queues_arglist into the inferior's memory space to prepare for |
137 | // the call. |
138 | // |
139 | // Returns the address of the arguments written down in the inferior process, |
140 | // which can be used to make the function call. |
141 | |
142 | lldb::addr_t |
143 | AppleGetQueuesHandler::SetupGetQueuesFunction(Thread &thread, |
144 | ValueList &get_queues_arglist) { |
145 | ThreadSP thread_sp(thread.shared_from_this()); |
146 | ExecutionContext exe_ctx(thread_sp); |
147 | |
148 | Address impl_code_address; |
149 | DiagnosticManager diagnostics; |
150 | Log *log = GetLog(mask: LLDBLog::SystemRuntime); |
151 | lldb::addr_t args_addr = LLDB_INVALID_ADDRESS; |
152 | |
153 | FunctionCaller *get_queues_caller = nullptr; |
154 | |
155 | // Scope for mutex locker: |
156 | { |
157 | std::lock_guard<std::mutex> guard(m_get_queues_function_mutex); |
158 | |
159 | // First stage is to make the ClangUtility to hold our injected function: |
160 | |
161 | if (!m_get_queues_impl_code_up) { |
162 | if (g_get_current_queues_function_code != nullptr) { |
163 | auto utility_fn_or_error = exe_ctx.GetTargetRef().CreateUtilityFunction( |
164 | expression: g_get_current_queues_function_code, |
165 | name: g_get_current_queues_function_name, language: eLanguageTypeC, exe_ctx); |
166 | if (!utility_fn_or_error) { |
167 | LLDB_LOG_ERROR(log, utility_fn_or_error.takeError(), |
168 | "Failed to create UtilityFunction for queues " |
169 | "introspection: {0}." ); |
170 | return args_addr; |
171 | } |
172 | m_get_queues_impl_code_up = std::move(*utility_fn_or_error); |
173 | } else { |
174 | if (log) { |
175 | LLDB_LOGF(log, "No queues introspection code found." ); |
176 | diagnostics.Dump(log); |
177 | } |
178 | return LLDB_INVALID_ADDRESS; |
179 | } |
180 | } |
181 | |
182 | // Next make the runner function for our implementation utility function. |
183 | TypeSystemClangSP scratch_ts_sp = |
184 | ScratchTypeSystemClang::GetForTarget(target&: thread.GetProcess()->GetTarget()); |
185 | CompilerType get_queues_return_type = |
186 | scratch_ts_sp->GetBasicType(type: eBasicTypeVoid).GetPointerType(); |
187 | Status error; |
188 | get_queues_caller = m_get_queues_impl_code_up->MakeFunctionCaller( |
189 | return_type: get_queues_return_type, arg_value_list: get_queues_arglist, compilation_thread: thread_sp, error); |
190 | if (error.Fail() || get_queues_caller == nullptr) { |
191 | LLDB_LOGF(log, |
192 | "Could not get function caller for get-queues function: %s." , |
193 | error.AsCString()); |
194 | return args_addr; |
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_queues_caller->WriteFunctionArguments( |
206 | exe_ctx, args_addr_ref&: args_addr, arg_values&: get_queues_arglist, diagnostic_manager&: diagnostics)) { |
207 | if (log) { |
208 | LLDB_LOGF(log, "Error writing get-queues function arguments." ); |
209 | diagnostics.Dump(log); |
210 | } |
211 | return args_addr; |
212 | } |
213 | |
214 | return args_addr; |
215 | } |
216 | |
217 | AppleGetQueuesHandler::GetQueuesReturnInfo |
218 | AppleGetQueuesHandler::GetCurrentQueues(Thread &thread, addr_t page_to_free, |
219 | uint64_t page_to_free_size, |
220 | Status &error) { |
221 | lldb::StackFrameSP thread_cur_frame = thread.GetStackFrameAtIndex(idx: 0); |
222 | ProcessSP process_sp(thread.CalculateProcess()); |
223 | TargetSP target_sp(thread.CalculateTarget()); |
224 | TypeSystemClangSP scratch_ts_sp = |
225 | ScratchTypeSystemClang::GetForTarget(target&: *target_sp); |
226 | Log *log = GetLog(mask: LLDBLog::SystemRuntime); |
227 | |
228 | GetQueuesReturnInfo return_value; |
229 | return_value.queues_buffer_ptr = LLDB_INVALID_ADDRESS; |
230 | return_value.queues_buffer_size = 0; |
231 | return_value.count = 0; |
232 | |
233 | error.Clear(); |
234 | |
235 | if (!thread.SafeToCallFunctions()) { |
236 | LLDB_LOGF(log, "Not safe to call functions on thread 0x%" PRIx64, |
237 | thread.GetID()); |
238 | error.SetErrorString("Not safe to call functions on this thread." ); |
239 | return return_value; |
240 | } |
241 | |
242 | // Set up the arguments for a call to |
243 | |
244 | // struct get_current_queues_return_values |
245 | // { |
246 | // uint64_t queues_buffer_ptr; /* the address of the queues buffer from |
247 | // libBacktraceRecording */ |
248 | // uint64_t queues_buffer_size; /* the size of the queues buffer from |
249 | // libBacktraceRecording */ |
250 | // uint64_t count; /* the number of queues included in the |
251 | // queues buffer */ |
252 | // }; |
253 | // |
254 | // void |
255 | // __lldb_backtrace_recording_get_current_queues |
256 | // (struct |
257 | // get_current_queues_return_values |
258 | // *return_buffer, |
259 | // void *page_to_free, |
260 | // uint64_t page_to_free_size); |
261 | |
262 | // Where the return_buffer argument points to a 24 byte region of memory |
263 | // already allocated by lldb in the inferior process. |
264 | |
265 | CompilerType clang_void_ptr_type = |
266 | scratch_ts_sp->GetBasicType(type: eBasicTypeVoid).GetPointerType(); |
267 | Value return_buffer_ptr_value; |
268 | return_buffer_ptr_value.SetValueType(Value::ValueType::Scalar); |
269 | return_buffer_ptr_value.SetCompilerType(clang_void_ptr_type); |
270 | |
271 | CompilerType clang_int_type = scratch_ts_sp->GetBasicType(type: eBasicTypeInt); |
272 | Value debug_value; |
273 | debug_value.SetValueType(Value::ValueType::Scalar); |
274 | debug_value.SetCompilerType(clang_int_type); |
275 | |
276 | Value page_to_free_value; |
277 | page_to_free_value.SetValueType(Value::ValueType::Scalar); |
278 | page_to_free_value.SetCompilerType(clang_void_ptr_type); |
279 | |
280 | CompilerType clang_uint64_type = |
281 | scratch_ts_sp->GetBasicType(type: eBasicTypeUnsignedLongLong); |
282 | Value page_to_free_size_value; |
283 | page_to_free_size_value.SetValueType(Value::ValueType::Scalar); |
284 | page_to_free_size_value.SetCompilerType(clang_uint64_type); |
285 | |
286 | std::lock_guard<std::mutex> guard(m_get_queues_retbuffer_mutex); |
287 | if (m_get_queues_return_buffer_addr == LLDB_INVALID_ADDRESS) { |
288 | addr_t bufaddr = process_sp->AllocateMemory( |
289 | size: 32, permissions: ePermissionsReadable | ePermissionsWritable, error); |
290 | if (!error.Success() || bufaddr == LLDB_INVALID_ADDRESS) { |
291 | LLDB_LOGF(log, "Failed to allocate memory for return buffer for get " |
292 | "current queues func call" ); |
293 | return return_value; |
294 | } |
295 | m_get_queues_return_buffer_addr = bufaddr; |
296 | } |
297 | |
298 | ValueList argument_values; |
299 | |
300 | return_buffer_ptr_value.GetScalar() = m_get_queues_return_buffer_addr; |
301 | argument_values.PushValue(value: return_buffer_ptr_value); |
302 | |
303 | debug_value.GetScalar() = 0; |
304 | argument_values.PushValue(value: debug_value); |
305 | |
306 | if (page_to_free != LLDB_INVALID_ADDRESS) |
307 | page_to_free_value.GetScalar() = page_to_free; |
308 | else |
309 | page_to_free_value.GetScalar() = 0; |
310 | argument_values.PushValue(value: page_to_free_value); |
311 | |
312 | page_to_free_size_value.GetScalar() = page_to_free_size; |
313 | argument_values.PushValue(value: page_to_free_size_value); |
314 | |
315 | addr_t args_addr = SetupGetQueuesFunction(thread, get_queues_arglist&: argument_values); |
316 | |
317 | if (!m_get_queues_impl_code_up) { |
318 | error.SetErrorString( |
319 | "Unable to compile __introspection_dispatch_get_queues." ); |
320 | return return_value; |
321 | } |
322 | |
323 | FunctionCaller *get_queues_caller = |
324 | m_get_queues_impl_code_up->GetFunctionCaller(); |
325 | |
326 | if (get_queues_caller == nullptr) { |
327 | error.SetErrorString( |
328 | "Unable to get caller for call __introspection_dispatch_get_queues" ); |
329 | return return_value; |
330 | } |
331 | |
332 | DiagnosticManager diagnostics; |
333 | ExecutionContext exe_ctx; |
334 | EvaluateExpressionOptions options; |
335 | options.SetUnwindOnError(true); |
336 | options.SetIgnoreBreakpoints(true); |
337 | options.SetStopOthers(true); |
338 | #if __has_feature(address_sanitizer) |
339 | options.SetTimeout(process_sp->GetUtilityExpressionTimeout()); |
340 | #else |
341 | options.SetTimeout(std::chrono::milliseconds(500)); |
342 | #endif |
343 | options.SetTryAllThreads(false); |
344 | options.SetIsForUtilityExpr(true); |
345 | thread.CalculateExecutionContext(exe_ctx); |
346 | |
347 | ExpressionResults func_call_ret; |
348 | Value results; |
349 | func_call_ret = get_queues_caller->ExecuteFunction( |
350 | exe_ctx, args_addr_ptr: &args_addr, options, diagnostic_manager&: diagnostics, results); |
351 | if (func_call_ret != eExpressionCompleted || !error.Success()) { |
352 | LLDB_LOGF(log, |
353 | "Unable to call introspection_get_dispatch_queues(), got " |
354 | "ExpressionResults %d, error contains %s" , |
355 | func_call_ret, error.AsCString("" )); |
356 | error.SetErrorString("Unable to call introspection_get_dispatch_queues() " |
357 | "for list of queues" ); |
358 | return return_value; |
359 | } |
360 | |
361 | return_value.queues_buffer_ptr = m_process->ReadUnsignedIntegerFromMemory( |
362 | load_addr: m_get_queues_return_buffer_addr, byte_size: 8, LLDB_INVALID_ADDRESS, error); |
363 | if (!error.Success() || |
364 | return_value.queues_buffer_ptr == LLDB_INVALID_ADDRESS) { |
365 | return_value.queues_buffer_ptr = LLDB_INVALID_ADDRESS; |
366 | return return_value; |
367 | } |
368 | |
369 | return_value.queues_buffer_size = m_process->ReadUnsignedIntegerFromMemory( |
370 | load_addr: m_get_queues_return_buffer_addr + 8, byte_size: 8, fail_value: 0, error); |
371 | |
372 | if (!error.Success()) { |
373 | return_value.queues_buffer_ptr = LLDB_INVALID_ADDRESS; |
374 | return return_value; |
375 | } |
376 | |
377 | return_value.count = m_process->ReadUnsignedIntegerFromMemory( |
378 | load_addr: m_get_queues_return_buffer_addr + 16, byte_size: 8, fail_value: 0, error); |
379 | if (!error.Success()) { |
380 | return_value.queues_buffer_ptr = LLDB_INVALID_ADDRESS; |
381 | return return_value; |
382 | } |
383 | |
384 | LLDB_LOGF(log, |
385 | "AppleGetQueuesHandler called " |
386 | "__introspection_dispatch_get_queues (page_to_free == " |
387 | "0x%" PRIx64 ", size = %" PRId64 "), returned page is at 0x%" PRIx64 |
388 | ", size %" PRId64 ", count = %" PRId64, |
389 | page_to_free, page_to_free_size, return_value.queues_buffer_ptr, |
390 | return_value.queues_buffer_size, return_value.count); |
391 | |
392 | return return_value; |
393 | } |
394 | |