compiler-rt/lib/sanitizer_common/sanitizer_symbolizer_mac.cpp - llvm-project - Git at Google

 //===-- sanitizer_symbolizer_mac.cpp --------------------------------------===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 //
 // This file is shared between various sanitizers' runtime libraries.
 //
 // Implementation of Mac-specific "atos" symbolizer.
 //===----------------------------------------------------------------------===//

 #include "sanitizer_platform.h"
 #if SANITIZER_MAC

 #include "sanitizer_allocator_internal.h"
 #include "sanitizer_mac.h"
 #include "sanitizer_symbolizer_mac.h"

 #include <dlfcn.h>
 #include <errno.h>
 #include <mach/mach.h>
 #include <stdlib.h>
 #include <sys/wait.h>
 #include <unistd.h>
 #include <util.h>

 namespace __sanitizer {

 bool DlAddrSymbolizer::SymbolizePC(uptr addr, SymbolizedStack *stack) {
   Dl_info info;
   int result = dladdr((const void *)addr, &info);
   if (!result) return false;

   // Compute offset if possible. `dladdr()` doesn't always ensure that `addr >=
   // sym_addr` so only compute the offset when this holds. Failure to find the
   // function offset is not treated as a failure because it might still be
   // possible to get the symbol name.
   uptr sym_addr = reinterpret_cast<uptr>(info.dli_saddr);
   if (addr >= sym_addr) {
     stack->info.function_offset = addr - sym_addr;
   }

   const char *demangled = DemangleSwiftAndCXX(info.dli_sname);
   if (!demangled) return false;
   stack->info.function = internal_strdup(demangled);
   return true;
 }

 bool DlAddrSymbolizer::SymbolizeData(uptr addr, DataInfo *datainfo) {
   Dl_info info;
   int result = dladdr((const void *)addr, &info);
   if (!result) return false;
   const char *demangled = DemangleSwiftAndCXX(info.dli_sname);
   datainfo->name = internal_strdup(demangled);
   datainfo->start = (uptr)info.dli_saddr;
   return true;
 }

 #define K_ATOS_ENV_VAR "__check_mach_ports_lookup"

 // This cannot live in `AtosSymbolizerProcess` because instances of that object
 // are allocated by the internal allocator which under ASan is poisoned with
 // kAsanInternalHeapMagic.
 static char kAtosMachPortEnvEntry[] = K_ATOS_ENV_VAR "=000000000000000";

 class AtosSymbolizerProcess final : public SymbolizerProcess {
  public:
   explicit AtosSymbolizerProcess(const char *path)
       : SymbolizerProcess(path, /*use_posix_spawn*/ true) {
     pid_str_[0] = '\0';
   }

   void LateInitialize() {
     if (SANITIZER_IOSSIM) {
       // `putenv()` may call malloc/realloc so it is only safe to do this
       // during LateInitialize() or later (i.e. we can't do this in the
       // constructor).  We also can't do this in `StartSymbolizerSubprocess()`
       // because in TSan we switch allocators when we're symbolizing.
       // We use `putenv()` rather than `setenv()` so that we can later directly
       // write into the storage without LibC getting involved to change what the
       // variable is set to
       int result = putenv(kAtosMachPortEnvEntry);
       CHECK_EQ(result, 0);
     }
   }

  private:
   bool StartSymbolizerSubprocess() override {
     // Configure sandbox before starting atos process.

     // Put the string command line argument in the object so that it outlives
     // the call to GetArgV.
     internal_snprintf(pid_str_, sizeof(pid_str_), "%d", internal_getpid());

     if (SANITIZER_IOSSIM) {
       // `atos` in the simulator is restricted in its ability to retrieve the
       // task port for the target process (us) so we need to do extra work
       // to pass our task port to it.
       mach_port_t ports[]{mach_task_self()};
       kern_return_t ret =
           mach_ports_register(mach_task_self(), ports, /*count=*/1);
       CHECK_EQ(ret, KERN_SUCCESS);

       // Set environment variable that signals to `atos` that it should look
       // for our task port. We can't call `setenv()` here because it might call
       // malloc/realloc. To avoid that we instead update the
       // `mach_port_env_var_entry_` variable with our current PID.
       uptr count = internal_snprintf(kAtosMachPortEnvEntry,
                                      sizeof(kAtosMachPortEnvEntry),
                                      K_ATOS_ENV_VAR "=%s", pid_str_);
       CHECK_GE(count, sizeof(K_ATOS_ENV_VAR) + internal_strlen(pid_str_));
       // Document our assumption but without calling `getenv()` in normal
       // builds.
       DCHECK(getenv(K_ATOS_ENV_VAR));
       DCHECK_EQ(internal_strcmp(getenv(K_ATOS_ENV_VAR), pid_str_), 0);
     }

     return SymbolizerProcess::StartSymbolizerSubprocess();
   }

   bool ReachedEndOfOutput(const char *buffer, uptr length) const override {
     return (length >= 1 && buffer[length - 1] == '\n');
   }

   void GetArgV(const char *path_to_binary,
                const char *(&argv)[kArgVMax]) const override {
     int i = 0;
     argv[i++] = path_to_binary;
     argv[i++] = "-p";
     argv[i++] = &pid_str_[0];
     if (GetMacosAlignedVersion() == MacosVersion(10, 9)) {
       // On Mavericks atos prints a deprecation warning which we suppress by
       // passing -d. The warning isn't present on other OSX versions, even the
       // newer ones.
       argv[i++] = "-d";
     }
     argv[i++] = nullptr;
   }

   char pid_str_[16];
   // Space for `\0` in `K_ATOS_ENV_VAR` is reused for `=`.
   static_assert(sizeof(kAtosMachPortEnvEntry) ==
                     (sizeof(K_ATOS_ENV_VAR) + sizeof(pid_str_)),
                 "sizes should match");
 };

 #undef K_ATOS_ENV_VAR

 static bool ParseCommandOutput(const char *str, uptr addr, char **out_name,
                                char **out_module, char **out_file, uptr *line,
                                uptr *start_address) {
   // Trim ending newlines.
   char *trim;
   ExtractTokenUpToDelimiter(str, "\n", &trim);

   // The line from `atos` is in one of these formats:
   //   myfunction (in library.dylib) (sourcefile.c:17)
   //   myfunction (in library.dylib) + 0x1fe
   //   myfunction (in library.dylib) + 15
   //   0xdeadbeef (in library.dylib) + 0x1fe
   //   0xdeadbeef (in library.dylib) + 15
   //   0xdeadbeef (in library.dylib)
   //   0xdeadbeef

   const char *rest = trim;
   char *symbol_name;
   rest = ExtractTokenUpToDelimiter(rest, " (in ", &symbol_name);
   if (rest[0] == '\0') {
     InternalFree(symbol_name);
     InternalFree(trim);
     return false;
   }

   if (internal_strncmp(symbol_name, "0x", 2) != 0)
     *out_name = symbol_name;
   else
     InternalFree(symbol_name);
   rest = ExtractTokenUpToDelimiter(rest, ") ", out_module);

   if (rest[0] == '(') {
     if (out_file) {
       rest++;
       rest = ExtractTokenUpToDelimiter(rest, ":", out_file);
       char *extracted_line_number;
       rest = ExtractTokenUpToDelimiter(rest, ")", &extracted_line_number);
       if (line) *line = (uptr)internal_atoll(extracted_line_number);
       InternalFree(extracted_line_number);
     }
   } else if (rest[0] == '+') {
     rest += 2;
     uptr offset = internal_atoll(rest);
     if (start_address) *start_address = addr - offset;
   }

   InternalFree(trim);
   return true;
 }

 AtosSymbolizer::AtosSymbolizer(const char *path, LowLevelAllocator *allocator)
     : process_(new (*allocator) AtosSymbolizerProcess(path)) {}

 bool AtosSymbolizer::SymbolizePC(uptr addr, SymbolizedStack *stack) {
   if (!process_) return false;
   if (addr == 0) return false;
   char command[32];
   internal_snprintf(command, sizeof(command), "0x%zx\n", addr);
   const char *buf = process_->SendCommand(command);
   if (!buf) return false;
   uptr line;
   uptr start_address = AddressInfo::kUnknown;
   if (!ParseCommandOutput(buf, addr, &stack->info.function, &stack->info.module,
                           &stack->info.file, &line, &start_address)) {
     process_ = nullptr;
     return false;
   }
   stack->info.line = (int)line;

   if (start_address == AddressInfo::kUnknown) {
     // Fallback to dladdr() to get function start address if atos doesn't report
     // it.
     Dl_info info;
     int result = dladdr((const void *)addr, &info);
     if (result)
       start_address = reinterpret_cast<uptr>(info.dli_saddr);
   }

   // Only assign to `function_offset` if we were able to get the function's
   // start address and we got a sensible `start_address` (dladdr doesn't always
   // ensure that `addr >= sym_addr`).
   if (start_address != AddressInfo::kUnknown && addr >= start_address) {
     stack->info.function_offset = addr - start_address;
   }
   return true;
 }

 bool AtosSymbolizer::SymbolizeData(uptr addr, DataInfo *info) {
   if (!process_) return false;
   char command[32];
   internal_snprintf(command, sizeof(command), "0x%zx\n", addr);
   const char *buf = process_->SendCommand(command);
   if (!buf) return false;
   if (!ParseCommandOutput(buf, addr, &info->name, &info->module, nullptr,
                           nullptr, &info->start)) {
     process_ = nullptr;
     return false;
   }
   return true;
 }

 void AtosSymbolizer::LateInitialize() { process_->LateInitialize(); }

 }  // namespace __sanitizer

 #endif  // SANITIZER_MAC
	//===-- sanitizer_symbolizer_mac.cpp --------------------------------------===//
	//
	// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
	// See https://llvm.org/LICENSE.txt for license information.
	// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
	//
	//===----------------------------------------------------------------------===//
	//
	// This file is shared between various sanitizers' runtime libraries.
	//
	// Implementation of Mac-specific "atos" symbolizer.
	//===----------------------------------------------------------------------===//

	#include "sanitizer_platform.h"
	#if SANITIZER_MAC

	#include "sanitizer_allocator_internal.h"
	#include "sanitizer_mac.h"
	#include "sanitizer_symbolizer_mac.h"

	#include <dlfcn.h>
	#include <errno.h>
	#include <mach/mach.h>
	#include <stdlib.h>
	#include <sys/wait.h>
	#include <unistd.h>
	#include <util.h>

	namespace __sanitizer {

	bool DlAddrSymbolizer::SymbolizePC(uptr addr, SymbolizedStack *stack) {
	Dl_info info;
	int result = dladdr((const void *)addr, &info);
	if (!result) return false;

	// Compute offset if possible. `dladdr()` doesn't always ensure that `addr >=
	// sym_addr` so only compute the offset when this holds. Failure to find the
	// function offset is not treated as a failure because it might still be
	// possible to get the symbol name.
	uptr sym_addr = reinterpret_cast<uptr>(info.dli_saddr);
	if (addr >= sym_addr) {
	stack->info.function_offset = addr - sym_addr;
	}

	const char *demangled = DemangleSwiftAndCXX(info.dli_sname);
	if (!demangled) return false;
	stack->info.function = internal_strdup(demangled);
	return true;
	}

	bool DlAddrSymbolizer::SymbolizeData(uptr addr, DataInfo *datainfo) {
	Dl_info info;
	int result = dladdr((const void *)addr, &info);
	if (!result) return false;
	const char *demangled = DemangleSwiftAndCXX(info.dli_sname);
	datainfo->name = internal_strdup(demangled);
	datainfo->start = (uptr)info.dli_saddr;
	return true;
	}

	#define K_ATOS_ENV_VAR "__check_mach_ports_lookup"

	// This cannot live in `AtosSymbolizerProcess` because instances of that object
	// are allocated by the internal allocator which under ASan is poisoned with
	// kAsanInternalHeapMagic.
	static char kAtosMachPortEnvEntry[] = K_ATOS_ENV_VAR "=000000000000000";

	class AtosSymbolizerProcess final : public SymbolizerProcess {
	public:
	explicit AtosSymbolizerProcess(const char *path)
	: SymbolizerProcess(path, /use_posix_spawn/ true) {
	pid_str_[0] = '\0';
	}

	void LateInitialize() {
	if (SANITIZER_IOSSIM) {
	// `putenv()` may call malloc/realloc so it is only safe to do this
	// during LateInitialize() or later (i.e. we can't do this in the
	// constructor). We also can't do this in `StartSymbolizerSubprocess()`
	// because in TSan we switch allocators when we're symbolizing.
	// We use `putenv()` rather than `setenv()` so that we can later directly
	// write into the storage without LibC getting involved to change what the
	// variable is set to
	int result = putenv(kAtosMachPortEnvEntry);
	CHECK_EQ(result, 0);
	}
	}

	private:
	bool StartSymbolizerSubprocess() override {
	// Configure sandbox before starting atos process.

	// Put the string command line argument in the object so that it outlives
	// the call to GetArgV.
	internal_snprintf(pid_str_, sizeof(pid_str_), "%d", internal_getpid());

	if (SANITIZER_IOSSIM) {
	// `atos` in the simulator is restricted in its ability to retrieve the
	// task port for the target process (us) so we need to do extra work
	// to pass our task port to it.
	mach_port_t ports[]{mach_task_self()};
	kern_return_t ret =
	mach_ports_register(mach_task_self(), ports, /count=/1);
	CHECK_EQ(ret, KERN_SUCCESS);

	// Set environment variable that signals to `atos` that it should look
	// for our task port. We can't call `setenv()` here because it might call
	// malloc/realloc. To avoid that we instead update the
	// `mach_port_env_var_entry_` variable with our current PID.
	uptr count = internal_snprintf(kAtosMachPortEnvEntry,
	sizeof(kAtosMachPortEnvEntry),
	K_ATOS_ENV_VAR "=%s", pid_str_);
	CHECK_GE(count, sizeof(K_ATOS_ENV_VAR) + internal_strlen(pid_str_));
	// Document our assumption but without calling `getenv()` in normal
	// builds.
	DCHECK(getenv(K_ATOS_ENV_VAR));
	DCHECK_EQ(internal_strcmp(getenv(K_ATOS_ENV_VAR), pid_str_), 0);
	}

	return SymbolizerProcess::StartSymbolizerSubprocess();
	}

	bool ReachedEndOfOutput(const char *buffer, uptr length) const override {
	return (length >= 1 && buffer[length - 1] == '\n');
	}

	void GetArgV(const char *path_to_binary,
	const char *(&argv)[kArgVMax]) const override {
	int i = 0;
	argv[i++] = path_to_binary;
	argv[i++] = "-p";
	argv[i++] = &pid_str_[0];
	if (GetMacosAlignedVersion() == MacosVersion(10, 9)) {
	// On Mavericks atos prints a deprecation warning which we suppress by
	// passing -d. The warning isn't present on other OSX versions, even the
	// newer ones.
	argv[i++] = "-d";
	}
	argv[i++] = nullptr;
	}

	char pid_str_[16];
	// Space for `\0` in `K_ATOS_ENV_VAR` is reused for `=`.
	static_assert(sizeof(kAtosMachPortEnvEntry) ==
	(sizeof(K_ATOS_ENV_VAR) + sizeof(pid_str_)),
	"sizes should match");
	};

	#undef K_ATOS_ENV_VAR

	static bool ParseCommandOutput(const char str, uptr addr, char *out_name,
	char out_module, char out_file, uptr *line,
	uptr *start_address) {
	// Trim ending newlines.
	char *trim;
	ExtractTokenUpToDelimiter(str, "\n", &trim);

	// The line from `atos` is in one of these formats:
	// myfunction (in library.dylib) (sourcefile.c:17)
	// myfunction (in library.dylib) + 0x1fe
	// myfunction (in library.dylib) + 15
	// 0xdeadbeef (in library.dylib) + 0x1fe
	// 0xdeadbeef (in library.dylib) + 15
	// 0xdeadbeef (in library.dylib)
	// 0xdeadbeef

	const char *rest = trim;
	char *symbol_name;
	rest = ExtractTokenUpToDelimiter(rest, " (in ", &symbol_name);
	if (rest[0] == '\0') {
	InternalFree(symbol_name);
	InternalFree(trim);
	return false;
	}

	if (internal_strncmp(symbol_name, "0x", 2) != 0)
	*out_name = symbol_name;
	else
	InternalFree(symbol_name);
	rest = ExtractTokenUpToDelimiter(rest, ") ", out_module);

	if (rest[0] == '(') {
	if (out_file) {
	rest++;
	rest = ExtractTokenUpToDelimiter(rest, ":", out_file);
	char *extracted_line_number;
	rest = ExtractTokenUpToDelimiter(rest, ")", &extracted_line_number);
	if (line) *line = (uptr)internal_atoll(extracted_line_number);
	InternalFree(extracted_line_number);
	}
	} else if (rest[0] == '+') {
	rest += 2;
	uptr offset = internal_atoll(rest);
	if (start_address) *start_address = addr - offset;
	}

	InternalFree(trim);
	return true;
	}

	AtosSymbolizer::AtosSymbolizer(const char path, LowLevelAllocator allocator)
	: process_(new (*allocator) AtosSymbolizerProcess(path)) {}

	bool AtosSymbolizer::SymbolizePC(uptr addr, SymbolizedStack *stack) {
	if (!process_) return false;
	if (addr == 0) return false;
	char command[32];
	internal_snprintf(command, sizeof(command), "0x%zx\n", addr);
	const char *buf = process_->SendCommand(command);
	if (!buf) return false;
	uptr line;
	uptr start_address = AddressInfo::kUnknown;
	if (!ParseCommandOutput(buf, addr, &stack->info.function, &stack->info.module,
	&stack->info.file, &line, &start_address)) {
	process_ = nullptr;
	return false;
	}
	stack->info.line = (int)line;

	if (start_address == AddressInfo::kUnknown) {
	// Fallback to dladdr() to get function start address if atos doesn't report
	// it.
	Dl_info info;
	int result = dladdr((const void *)addr, &info);
	if (result)
	start_address = reinterpret_cast<uptr>(info.dli_saddr);
	}

	// Only assign to `function_offset` if we were able to get the function's
	// start address and we got a sensible `start_address` (dladdr doesn't always
	// ensure that `addr >= sym_addr`).
	if (start_address != AddressInfo::kUnknown && addr >= start_address) {
	stack->info.function_offset = addr - start_address;
	}
	return true;
	}

	bool AtosSymbolizer::SymbolizeData(uptr addr, DataInfo *info) {
	if (!process_) return false;
	char command[32];
	internal_snprintf(command, sizeof(command), "0x%zx\n", addr);
	const char *buf = process_->SendCommand(command);
	if (!buf) return false;
	if (!ParseCommandOutput(buf, addr, &info->name, &info->module, nullptr,
	nullptr, &info->start)) {
	process_ = nullptr;
	return false;
	}
	return true;
	}

	void AtosSymbolizer::LateInitialize() { process_->LateInitialize(); }

	} // namespace __sanitizer

	#endif // SANITIZER_MAC