The Tor Browser: toolkit/xre/nsSigHandlers.cpp@129ffea94266 (annotated)

toolkit/xre/nsSigHandlers.cpp@129ffea94266 (annotated)

toolkit/xre/nsSigHandlers.cpp

Sat, 03 Jan 2015 20:18:00 +0100

author: Michael Schloh von Bennewitz <michael@schloh.com>
date: Sat, 03 Jan 2015 20:18:00 +0100
branch: TOR_BUG_3246
changeset 7: 129ffea94266
permissions: -rw-r--r--

Conditionally enable double key logic according to:
private browsing mode or privacy.thirdparty.isolate preference and
implement in GetCookieStringCommon and FindCookie where it counts...
With some reservations of how to convince FindCookie users to test
condition and pass a nullptr when disabling double key logic.

 /* -*- 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
 #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;
 // NB: keep me up to date with the same variable in
 // ipc/chromium/chrome/common/ipc_channel_posix.cc
 static const int kClientChannelFd = 3;
 #if defined(LINUX) && defined(DEBUG) && \
       (defined(__i386) || defined(__x86_64) || defined(PPC))
 #define CRAWL_STACK_ON_SIGSEGV
 #endif
 #if defined(CRAWL_STACK_ON_SIGSEGV)
 #include <unistd.h>
 #include "nsISupportsUtils.h"
 #include "nsStackWalk.h"
 extern "C" {
 static void PrintStackFrame(void *aPC, void *aSP, void *aClosure)
 {
   char buf[1024];
   nsCodeAddressDetails details;
   NS_DescribeCodeAddress(aPC, &details);
   NS_FormatCodeAddressDetails(aPC, &details, buf, sizeof(buf));
   fputs(buf, 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());
   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
 /*
  * SSE traps raise these exception codes, which are defined in internal NT headers
  * but not winbase.h
  */
 #define STATUS_FLOAT_MULTIPLE_FAULTS 0xC00002B4
 #define STATUS_FLOAT_MULTIPLE_TRAPS  0xC00002B5
 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

The Tor Browser / annotate

toolkit/xre/nsSigHandlers.cpp@129ffea94266 (annotated)

toolkit/xre/nsSigHandlers.cpp