gecko-dev/toolkit/xre/nsSigHandlers.cpp

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11 KiB
C++

/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
/*
* This module is supposed to abstract signal handling away from the other
* platforms that do not support it.
*/
#include "nsSigHandlers.h"
#ifdef XP_UNIX
#include <signal.h>
#include <stdio.h>
#include <string.h>
#include "prthread.h"
#include "plstr.h"
#include "prenv.h"
#include "nsDebug.h"
#include "nsXULAppAPI.h"
#if defined(LINUX)
#include <sys/time.h>
#include <sys/resource.h>
#include <unistd.h>
#include <stdlib.h> // atoi
#include <sys/prctl.h>
#ifndef ANDROID // no Android impl
# include <ucontext.h>
#endif
#endif
#if defined(SOLARIS)
#include <sys/resource.h>
#include <ucontext.h>
#endif
static char _progname[1024] = "huh?";
static unsigned int _gdb_sleep_duration = 300;
#if defined(LINUX) && defined(DEBUG) && \
(defined(__i386) || defined(__x86_64) || defined(PPC))
#define CRAWL_STACK_ON_SIGSEGV
#endif
#ifndef PR_SET_PTRACER
#define PR_SET_PTRACER 0x59616d61
#endif
#ifndef PR_SET_PTRACER_ANY
#define PR_SET_PTRACER_ANY ((unsigned long)-1)
#endif
#if defined(CRAWL_STACK_ON_SIGSEGV)
#include <unistd.h>
#include "nsISupportsUtils.h"
#include "nsStackWalk.h"
// NB: keep me up to date with the same variable in
// ipc/chromium/chrome/common/ipc_channel_posix.cc
static const int kClientChannelFd = 3;
extern "C" {
static void PrintStackFrame(uint32_t aFrameNumber, void *aPC, void *aSP,
void *aClosure)
{
char buf[1024];
nsCodeAddressDetails details;
NS_DescribeCodeAddress(aPC, &details);
NS_FormatCodeAddressDetails(buf, sizeof(buf), aFrameNumber, aPC, &details);
fprintf(stdout, "%s\n", buf);
fflush(stdout);
}
}
void
ah_crap_handler(int signum)
{
printf("\nProgram %s (pid = %d) received signal %d.\n",
_progname,
getpid(),
signum);
printf("Stack:\n");
NS_StackWalk(PrintStackFrame, /* skipFrames */ 2, /* maxFrames */ 0,
nullptr, 0, nullptr);
printf("Sleeping for %d seconds.\n",_gdb_sleep_duration);
printf("Type 'gdb %s %d' to attach your debugger to this thread.\n",
_progname,
getpid());
// Allow us to be ptraced by gdb on Linux with Yama restrictions enabled.
prctl(PR_SET_PTRACER, PR_SET_PTRACER_ANY);
sleep(_gdb_sleep_duration);
printf("Done sleeping...\n");
_exit(signum);
}
void
child_ah_crap_handler(int signum)
{
if (!getenv("MOZ_DONT_UNBLOCK_PARENT_ON_CHILD_CRASH"))
close(kClientChannelFd);
ah_crap_handler(signum);
}
#endif // CRAWL_STACK_ON_SIGSEGV
#ifdef MOZ_WIDGET_GTK
// Need this include for version test below.
#include <glib.h>
#endif
#if defined(MOZ_WIDGET_GTK) && (GLIB_MAJOR_VERSION > 2 || (GLIB_MAJOR_VERSION == 2 && GLIB_MINOR_VERSION >= 6))
static GLogFunc orig_log_func = nullptr;
extern "C" {
static void
my_glib_log_func(const gchar *log_domain, GLogLevelFlags log_level,
const gchar *message, gpointer user_data);
}
/* static */ void
my_glib_log_func(const gchar *log_domain, GLogLevelFlags log_level,
const gchar *message, gpointer user_data)
{
if (log_level & (G_LOG_LEVEL_ERROR | G_LOG_FLAG_FATAL | G_LOG_FLAG_RECURSION)) {
NS_DebugBreak(NS_DEBUG_ASSERTION, message, "glib assertion", __FILE__, __LINE__);
} else if (log_level & (G_LOG_LEVEL_CRITICAL | G_LOG_LEVEL_WARNING)) {
NS_DebugBreak(NS_DEBUG_WARNING, message, "glib warning", __FILE__, __LINE__);
}
orig_log_func(log_domain, log_level, message, nullptr);
}
#endif
#ifdef SA_SIGINFO
static void fpehandler(int signum, siginfo_t *si, void *context)
{
/* Integer divide by zero or integer overflow. */
/* Note: FPE_INTOVF is ignored on Intel, PowerPC and SPARC systems. */
if (si->si_code == FPE_INTDIV || si->si_code == FPE_INTOVF) {
NS_DebugBreak(NS_DEBUG_ABORT, "Divide by zero", nullptr, __FILE__, __LINE__);
}
#ifdef XP_MACOSX
ucontext_t *uc = (ucontext_t *)context;
#if defined(__i386__) || defined(__amd64__)
_STRUCT_FP_CONTROL *ctrl = &uc->uc_mcontext->__fs.__fpu_fcw;
ctrl->__invalid = ctrl->__denorm = ctrl->__zdiv = ctrl->__ovrfl = ctrl->__undfl = ctrl->__precis = 1;
_STRUCT_FP_STATUS *status = &uc->uc_mcontext->__fs.__fpu_fsw;
status->__invalid = status->__denorm = status->__zdiv = status->__ovrfl = status->__undfl =
status->__precis = status->__stkflt = status->__errsumm = 0;
__uint32_t *mxcsr = &uc->uc_mcontext->__fs.__fpu_mxcsr;
*mxcsr |= SSE_EXCEPTION_MASK; /* disable all SSE exceptions */
*mxcsr &= ~SSE_STATUS_FLAGS; /* clear all pending SSE exceptions */
#endif
#endif
#if defined(LINUX) && !defined(ANDROID)
ucontext_t *uc = (ucontext_t *)context;
#if defined(__i386__)
/*
* It seems that we have no access to mxcsr on Linux. libc
* seems to be translating cw/sw to mxcsr.
*/
unsigned long int *cw = &uc->uc_mcontext.fpregs->cw;
*cw |= FPU_EXCEPTION_MASK;
unsigned long int *sw = &uc->uc_mcontext.fpregs->sw;
*sw &= ~FPU_STATUS_FLAGS;
#endif
#if defined(__amd64__)
__uint16_t *cw = &uc->uc_mcontext.fpregs->cwd;
*cw |= FPU_EXCEPTION_MASK;
__uint16_t *sw = &uc->uc_mcontext.fpregs->swd;
*sw &= ~FPU_STATUS_FLAGS;
__uint32_t *mxcsr = &uc->uc_mcontext.fpregs->mxcsr;
*mxcsr |= SSE_EXCEPTION_MASK; /* disable all SSE exceptions */
*mxcsr &= ~SSE_STATUS_FLAGS; /* clear all pending SSE exceptions */
#endif
#endif
#ifdef SOLARIS
ucontext_t *uc = (ucontext_t *)context;
#if defined(__i386)
uint32_t *cw = &uc->uc_mcontext.fpregs.fp_reg_set.fpchip_state.state[0];
*cw |= FPU_EXCEPTION_MASK;
uint32_t *sw = &uc->uc_mcontext.fpregs.fp_reg_set.fpchip_state.state[1];
*sw &= ~FPU_STATUS_FLAGS;
/* address of the instruction that caused the exception */
uint32_t *ip = &uc->uc_mcontext.fpregs.fp_reg_set.fpchip_state.state[3];
uc->uc_mcontext.gregs[REG_PC] = *ip;
#endif
#if defined(__amd64__)
uint16_t *cw = &uc->uc_mcontext.fpregs.fp_reg_set.fpchip_state.cw;
*cw |= FPU_EXCEPTION_MASK;
uint16_t *sw = &uc->uc_mcontext.fpregs.fp_reg_set.fpchip_state.sw;
*sw &= ~FPU_STATUS_FLAGS;
uint32_t *mxcsr = &uc->uc_mcontext.fpregs.fp_reg_set.fpchip_state.mxcsr;
*mxcsr |= SSE_EXCEPTION_MASK; /* disable all SSE exceptions */
*mxcsr &= ~SSE_STATUS_FLAGS; /* clear all pending SSE exceptions */
#endif
#endif
}
#endif
void InstallSignalHandlers(const char *ProgramName)
{
PL_strncpy(_progname,ProgramName, (sizeof(_progname)-1) );
const char *gdbSleep = PR_GetEnv("MOZ_GDB_SLEEP");
if (gdbSleep && *gdbSleep)
{
unsigned int s;
if (1 == sscanf(gdbSleep, "%u", &s)) {
_gdb_sleep_duration = s;
}
}
#if defined(CRAWL_STACK_ON_SIGSEGV)
if (!getenv("XRE_NO_WINDOWS_CRASH_DIALOG")) {
void (*crap_handler)(int) =
GeckoProcessType_Default != XRE_GetProcessType() ?
child_ah_crap_handler :
ah_crap_handler;
signal(SIGSEGV, crap_handler);
signal(SIGILL, crap_handler);
signal(SIGABRT, crap_handler);
}
#endif // CRAWL_STACK_ON_SIGSEGV
#ifdef SA_SIGINFO
/* Install a handler for floating point exceptions and disable them if they occur. */
struct sigaction sa, osa;
sa.sa_flags = SA_ONSTACK | SA_RESTART | SA_SIGINFO;
sa.sa_sigaction = fpehandler;
sigemptyset(&sa.sa_mask);
sigaction(SIGFPE, &sa, &osa);
#endif
if (XRE_GetProcessType() == GeckoProcessType_Content) {
/*
* If the user is debugging a Gecko parent process in gdb and hits ^C to
* suspend, a SIGINT signal will be sent to the child. We ignore this signal
* so the child isn't killed.
*/
signal(SIGINT, SIG_IGN);
}
#if defined(DEBUG) && defined(LINUX)
const char *memLimit = PR_GetEnv("MOZ_MEM_LIMIT");
if (memLimit && *memLimit)
{
long m = atoi(memLimit);
m *= (1024*1024);
struct rlimit r;
r.rlim_cur = m;
r.rlim_max = m;
setrlimit(RLIMIT_AS, &r);
}
#endif
#if defined(SOLARIS)
#define NOFILES 512
// Boost Solaris file descriptors
{
struct rlimit rl;
if (getrlimit(RLIMIT_NOFILE, &rl) == 0)
if (rl.rlim_cur < NOFILES) {
rl.rlim_cur = NOFILES;
if (setrlimit(RLIMIT_NOFILE, &rl) < 0) {
perror("setrlimit(RLIMIT_NOFILE)");
fprintf(stderr, "Cannot exceed hard limit for open files");
}
#if defined(DEBUG)
if (getrlimit(RLIMIT_NOFILE, &rl) == 0)
printf("File descriptors set to %d\n", rl.rlim_cur);
#endif //DEBUG
}
}
#endif //SOLARIS
#if defined(MOZ_WIDGET_GTK) && (GLIB_MAJOR_VERSION > 2 || (GLIB_MAJOR_VERSION == 2 && GLIB_MINOR_VERSION >= 6))
const char *assertString = PR_GetEnv("XPCOM_DEBUG_BREAK");
if (assertString &&
(!strcmp(assertString, "suspend") ||
!strcmp(assertString, "stack") ||
!strcmp(assertString, "abort") ||
!strcmp(assertString, "trap") ||
!strcmp(assertString, "break"))) {
// Override the default glib logging function so we get stacks for it too.
orig_log_func = g_log_set_default_handler(my_glib_log_func, nullptr);
}
#endif
}
#elif XP_WIN
#include <windows.h>
#ifdef _M_IX86
/*
* WinNT.h prior to SDK7 does not expose the structure of the ExtendedRegisters for ia86.
* We known that MxCsr is at offset 0x18 and is a DWORD.
*/
#define MXCSR(ctx) (*(DWORD *)(((BYTE *)(ctx)->ExtendedRegisters) + 0x18))
#endif
#ifdef _M_X64
#define MXCSR(ctx) (ctx)->MxCsr
#endif
#if defined(_M_IX86) || defined(_M_X64)
#ifdef _M_X64
#define X87CW(ctx) (ctx)->FltSave.ControlWord
#define X87SW(ctx) (ctx)->FltSave.StatusWord
#else
#define X87CW(ctx) (ctx)->FloatSave.ControlWord
#define X87SW(ctx) (ctx)->FloatSave.StatusWord
#endif
static LPTOP_LEVEL_EXCEPTION_FILTER gFPEPreviousFilter;
LONG __stdcall FpeHandler(PEXCEPTION_POINTERS pe)
{
PEXCEPTION_RECORD e = (PEXCEPTION_RECORD)pe->ExceptionRecord;
CONTEXT *c = (CONTEXT*)pe->ContextRecord;
switch (e->ExceptionCode) {
case STATUS_FLOAT_DENORMAL_OPERAND:
case STATUS_FLOAT_DIVIDE_BY_ZERO:
case STATUS_FLOAT_INEXACT_RESULT:
case STATUS_FLOAT_INVALID_OPERATION:
case STATUS_FLOAT_OVERFLOW:
case STATUS_FLOAT_STACK_CHECK:
case STATUS_FLOAT_UNDERFLOW:
case STATUS_FLOAT_MULTIPLE_FAULTS:
case STATUS_FLOAT_MULTIPLE_TRAPS:
X87CW(c) |= FPU_EXCEPTION_MASK; /* disable all FPU exceptions */
X87SW(c) &= ~FPU_STATUS_FLAGS; /* clear all pending FPU exceptions */
#ifdef _M_IX86
if (c->ContextFlags & CONTEXT_EXTENDED_REGISTERS) {
#endif
MXCSR(c) |= SSE_EXCEPTION_MASK; /* disable all SSE exceptions */
MXCSR(c) &= ~SSE_STATUS_FLAGS; /* clear all pending SSE exceptions */
#ifdef _M_IX86
}
#endif
return EXCEPTION_CONTINUE_EXECUTION;
}
LONG action = EXCEPTION_CONTINUE_SEARCH;
if (gFPEPreviousFilter)
action = gFPEPreviousFilter(pe);
return action;
}
void InstallSignalHandlers(const char *ProgramName)
{
gFPEPreviousFilter = SetUnhandledExceptionFilter(FpeHandler);
}
#else
void InstallSignalHandlers(const char *ProgramName)
{
}
#endif
#else
#error No signal handling implementation for this platform.
#endif