blob: b53ebc5bef244183cfc468eef54758464c34dc94 [file] [log] [blame]
/*
* Copyright 2014 Google Inc.
*
* Use of this source code is governed by a BSD-style license that can be
* found in the LICENSE file.
*/
#include "tools/CrashHandler.h"
#include "include/private/base/SkDebug.h"
#include "src/base/SkLeanWindows.h"
#include <array> // for std::size
#include <stdlib.h>
#if defined(SK_BUILD_FOR_GOOGLE3)
#include "base/config.h" // May define GOOGLE_ENABLE_SIGNAL_HANDLERS.
#endif
#if defined(GOOGLE_ENABLE_SIGNAL_HANDLERS)
#include "base/process_state.h"
void SetupCrashHandler() { InstallSignalHandlers(); }
#else
#if defined(SK_BUILD_FOR_MAC)
// We only use local unwinding, so we can define this to select a faster implementation.
#define UNW_LOCAL_ONLY
#include <libunwind.h>
#include <cxxabi.h>
static void handler(int sig) {
unw_context_t context;
unw_getcontext(&context);
unw_cursor_t cursor;
unw_init_local(&cursor, &context);
SkDebugf("\nSignal %d:\n", sig);
while (unw_step(&cursor) > 0) {
static const size_t kMax = 256;
char mangled[kMax], demangled[kMax];
unw_word_t offset;
unw_get_proc_name(&cursor, mangled, kMax, &offset);
int ok;
size_t len = kMax;
abi::__cxa_demangle(mangled, demangled, &len, &ok);
SkDebugf("%s (+0x%zx)\n", ok == 0 ? demangled : mangled, (size_t)offset);
}
SkDebugf("\n");
// Exit NOW. Don't notify other threads, don't call anything registered with atexit().
_Exit(sig);
}
#elif defined(SK_BUILD_FOR_UNIX)
// We'd use libunwind here too, but it's a pain to get installed for
// both 32 and 64 bit on bots. Doesn't matter much: catchsegv is best anyway.
#include <cxxabi.h>
#include <dlfcn.h>
#include <string.h>
#if defined(__Fuchsia__)
#include <stdint.h>
// syslog crash reporting from Fuchsia's backtrace_request.h
//
// Special value we put in the first register to let the exception handler know
// that we are just requesting a backtrace and we should resume the thread.
#define BACKTRACE_REQUEST_MAGIC ((uint64_t)0xee726573756d65ee)
// Prints a backtrace, resuming the thread without killing the process.
__attribute__((always_inline)) static inline void backtrace_request(void) {
// Two instructions: one that sets a software breakpoint ("int3" on x64,
// "brk" on arm64) and one that writes the "magic" value in the first
// register ("a" on x64, "x0" on arm64).
//
// We set a software breakpoint to trigger the exception handling in
// crashsvc, which will print the debug info, including the backtrace.
//
// We write the "magic" value in the first register so that the exception
// handler can check for it and resume the thread if present.
#ifdef __x86_64__
__asm__("int3" : : "a"(BACKTRACE_REQUEST_MAGIC));
#endif
#ifdef __aarch64__
// This is what gdb uses.
__asm__(
"mov x0, %0\n"
"\tbrk 0"
:
: "r"(BACKTRACE_REQUEST_MAGIC)
: "x0");
#endif
}
#else
#include <execinfo.h>
#endif
static void handler(int sig) {
#if defined(__Fuchsia__)
backtrace_request();
#else
void* stack[64];
const int count = backtrace(stack, std::size(stack));
char** symbols = backtrace_symbols(stack, count);
SkDebugf("\nSignal %d [%s]:\n", sig, strsignal(sig));
for (int i = 0; i < count; i++) {
Dl_info info;
if (dladdr(stack[i], &info) && info.dli_sname) {
char demangled[256];
size_t len = std::size(demangled);
int ok;
abi::__cxa_demangle(info.dli_sname, demangled, &len, &ok);
if (ok == 0) {
SkDebugf(" %s\n", demangled);
continue;
}
}
SkDebugf(" %s\n", symbols[i]);
}
#endif
// Exit NOW. Don't notify other threads, don't call anything registered with
// atexit().
_Exit(sig);
}
#endif
#if defined(SK_BUILD_FOR_MAC) || defined(SK_BUILD_FOR_UNIX)
#include <signal.h>
void SetupCrashHandler() {
static const int kSignals[] = {
SIGABRT,
SIGBUS,
SIGFPE,
SIGILL,
SIGSEGV,
SIGTRAP,
};
for (size_t i = 0; i < sizeof(kSignals) / sizeof(kSignals[0]); i++) {
// Register our signal handler unless something's already done so (e.g. catchsegv).
void (*prev)(int) = signal(kSignals[i], handler);
if (prev != SIG_DFL) {
signal(kSignals[i], prev);
}
}
}
#elif defined(SK_BUILD_FOR_WIN)
#include <DbgHelp.h>
#include "include/private/base/SkMalloc.h"
static const struct {
const char* name;
const DWORD code;
} kExceptions[] = {
#define _(E) {#E, E}
_(EXCEPTION_ACCESS_VIOLATION),
_(EXCEPTION_BREAKPOINT),
_(EXCEPTION_INT_DIVIDE_BY_ZERO),
_(EXCEPTION_STACK_OVERFLOW),
// TODO: more?
#undef _
};
static LONG WINAPI handler(EXCEPTION_POINTERS* e) {
const DWORD code = e->ExceptionRecord->ExceptionCode;
SkDebugf("\nCaught exception %lu", code);
for (size_t i = 0; i < std::size(kExceptions); i++) {
if (kExceptions[i].code == code) {
SkDebugf(" %s", kExceptions[i].name);
}
}
SkDebugf("\n");
// We need to run SymInitialize before doing any of the stack walking below.
HANDLE hProcess = GetCurrentProcess();
SymInitialize(hProcess, 0, true);
STACKFRAME64 frame;
sk_bzero(&frame, sizeof(frame));
// Start frame off from the frame that triggered the exception.
CONTEXT* c = e->ContextRecord;
frame.AddrPC.Mode = AddrModeFlat;
frame.AddrStack.Mode = AddrModeFlat;
frame.AddrFrame.Mode = AddrModeFlat;
#if defined(_X86_)
frame.AddrPC.Offset = c->Eip;
frame.AddrStack.Offset = c->Esp;
frame.AddrFrame.Offset = c->Ebp;
const DWORD machineType = IMAGE_FILE_MACHINE_I386;
#elif defined(_AMD64_)
frame.AddrPC.Offset = c->Rip;
frame.AddrStack.Offset = c->Rsp;
frame.AddrFrame.Offset = c->Rbp;
const DWORD machineType = IMAGE_FILE_MACHINE_AMD64;
#elif defined(_M_ARM64)
frame.AddrPC.Offset = c->Pc;
frame.AddrStack.Offset = c->Sp;
frame.AddrFrame.Offset = c->Fp;
const DWORD machineType = IMAGE_FILE_MACHINE_ARM64;
#endif
#if !defined(SK_WINUWP)
while (StackWalk64(machineType,
GetCurrentProcess(),
GetCurrentThread(),
&frame,
c,
nullptr,
SymFunctionTableAccess64,
SymGetModuleBase64,
nullptr)) {
// Buffer to store symbol name in.
static const int kMaxNameLength = 1024;
uint8_t buffer[sizeof(IMAGEHLP_SYMBOL64) + kMaxNameLength];
sk_bzero(buffer, sizeof(buffer));
// We have to place IMAGEHLP_SYMBOL64 at the front, and fill in
// how much space it can use.
IMAGEHLP_SYMBOL64* symbol = reinterpret_cast<IMAGEHLP_SYMBOL64*>(&buffer);
symbol->SizeOfStruct = sizeof(IMAGEHLP_SYMBOL64);
symbol->MaxNameLength = kMaxNameLength - 1;
// Translate the current PC into a symbol and byte offset from the symbol.
DWORD64 offset;
SymGetSymFromAddr64(hProcess, frame.AddrPC.Offset, &offset, symbol);
SkDebugf("%s +%llx\n", symbol->Name, offset);
}
#endif //SK_WINUWP
// Exit NOW. Don't notify other threads, don't call anything registered with atexit().
_exit(1);
// The compiler wants us to return something. This is what we'd do
// if we didn't _exit().
return EXCEPTION_EXECUTE_HANDLER;
}
void SetupCrashHandler() {
SetUnhandledExceptionFilter(handler);
}
#else
void SetupCrashHandler() { }
#endif
#endif // SK_BUILD_FOR_GOOGLE3?