diff options
Diffstat (limited to 'toolkit/xre/nsSigHandlers.cpp')
| -rw-r--r-- | toolkit/xre/nsSigHandlers.cpp | 404 |
1 files changed, 404 insertions, 0 deletions
diff --git a/toolkit/xre/nsSigHandlers.cpp b/toolkit/xre/nsSigHandlers.cpp new file mode 100644 index 000000000..098d9ae7e --- /dev/null +++ b/toolkit/xre/nsSigHandlers.cpp @@ -0,0 +1,404 @@ +/* -*- 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 const char* gProgname = "huh?"; + +// Note: some tests manipulate this value. +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 "mozilla/StackWalk.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]; + MozCodeAddressDetails details; + + MozDescribeCodeAddress(aPC, &details); + MozFormatCodeAddressDetails(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", + gProgname, + getpid(), + signum); + + printf("Stack:\n"); + MozStackWalk(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", + gProgname, + 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 *aProgname) +{ + const char* tmp = PL_strdup(aProgname); + if (tmp) { + gProgname = tmp; + } + + 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_IsParentProcess()) { + /* + * 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 *aProgname) +{ + gFPEPreviousFilter = SetUnhandledExceptionFilter(FpeHandler); +} + +#else + +void InstallSignalHandlers(const char *aProgname) +{ +} + +#endif + +#else +#error No signal handling implementation for this platform. +#endif |