C++ VG_TRACK函数代码示例

/* A thread acquires a mutex.  Fails if:
    - thread is not blocked waiting for the mutex
    - mutex is held by another thread
 */
void VG_(tm_mutex_acquire)(ThreadId tid, Addr mutexp)
{
   struct mutex *mx;

   mx = mutex_check_initialized(tid, mutexp, "acquiring");   
   
   switch(mx->state) {
   case MX_Unlocking:		/* ownership transfer or relock */
      VG_TRACK( post_mutex_unlock, mx->owner, (void *)mutexp );
      if (mx->owner != tid)
	 thread_unblock_mutex(tid, mx, "acquiring mutex");
      break;

   case MX_Free:
      thread_unblock_mutex(tid, mx, "acquiring mutex");
      break;

   case MX_Locked:
      if (debug_mutex)
	 VG_(printf)("mutex=%p mx->state=%s\n", mutexp, pp_mutexstate(mx));
      VG_TRACK( post_mutex_unlock, mx->owner, (void *)mutexp );
      mutex_report(tid, mutexp, MXE_Locked, "acquiring");
      thread_unblock_mutex(tid, mx, "acquiring mutex");
      break;

   case MX_Init:
   case MX_Dead:
      vg_assert(0);
   } 
     
   mx->owner = tid;
   mutex_setstate(tid, mx, MX_Locked);

   VG_TRACK( post_mutex_lock, tid, (void *)mutexp );
}

void VG_(unknown_esp_update)(Addr new_ESP)
{
   Addr old_ESP = VG_(get_archreg)(R_ESP);
   Int  delta   = (Int)new_ESP - (Int)old_ESP;

   if (delta < -(VG_HUGE_DELTA) || VG_HUGE_DELTA < delta) {
      /* %esp has changed by more than HUGE_DELTA.  We take this to mean
         that the application is switching to a new stack, for whatever
         reason. 
       
         JRS 20021001: following discussions with John Regehr, if a stack
         switch happens, it seems best not to mess at all with memory
         permissions.  Seems to work well with Netscape 4.X.  Really the
         only remaining difficulty is knowing exactly when a stack switch is
         happening. */
      if (VG_(clo_verbosity) > 1)
           VG_(message)(Vg_UserMsg, "Warning: client switching stacks?  "
                                    "%%esp: %p --> %p", old_ESP, new_ESP);
   } else if (delta < 0) {
      VG_TRACK( new_mem_stack, new_ESP, -delta );

   } else if (delta > 0) {
      VG_TRACK( die_mem_stack, old_ESP,  delta );
   }
}

/* Allocate memory, noticing whether or not we are doing the full
   instrumentation thing. */
static __inline__
void* alloc_and_new_mem ( ThreadState* tst, UInt size, UInt alignment,
                          Bool is_zeroed, VgAllocKind kind )
{
   Addr p;

   VGP_PUSHCC(VgpCliMalloc);

   vg_cmalloc_n_mallocs ++;
   vg_cmalloc_bs_mallocd += size;

   vg_assert(alignment >= 4);
   if (alignment == 4)
      p = (Addr)VG_(arena_malloc)(VG_AR_CLIENT, size);
   else
      p = (Addr)VG_(arena_malloc_aligned)(VG_AR_CLIENT, alignment, size);

   if (needs_shadow_chunks())
      addShadowChunk ( tst, p, size, kind );

   VG_TRACK( ban_mem_heap, p-VG_AR_CLIENT_REDZONE_SZB, 
                           VG_AR_CLIENT_REDZONE_SZB );
   VG_TRACK( new_mem_heap, p, size, is_zeroed );
   VG_TRACK( ban_mem_heap, p+size, VG_AR_CLIENT_REDZONE_SZB );

   VGP_POPCC(VgpCliMalloc);
   return (void*)p;
}

void VG_(sigframe_destroy)( ThreadId tid, Bool isRT )
{
   Addr          esp;
   ThreadState*  tst;
   SizeT	 size;
   Int		 sigNo;

   tst = VG_(get_ThreadState)(tid);

   
   esp   = tst->arch.vex.guest_ESP;

   if (!isRT)
      size = restore_sigframe(tst, (struct sigframe *)esp, &sigNo);
   else
      size = restore_rt_sigframe(tst, (struct rt_sigframe *)esp, &sigNo);

   VG_TRACK( die_mem_stack_signal, esp - VG_STACK_REDZONE_SZB,
             size + VG_STACK_REDZONE_SZB );

   if (VG_(clo_trace_signals))
      VG_(message)(
         Vg_DebugMsg, 
         "VG_(signal_return) (thread %d): isRT=%d valid magic; EIP=%#x\n",
         tid, isRT, tst->arch.vex.guest_EIP);

   
   VG_TRACK( post_deliver_signal, tid, sigNo );
}

/* EXPORTED */
void VG_(sigframe_destroy)( ThreadId tid, Bool isRT )
{
   Addr          sp;
   ThreadState*  tst;
   SizeT         size;
   Int           sigNo;

   tst = VG_(get_ThreadState)(tid);

   /* Correctly reestablish the frame base address. */
   sp   = tst->arch.vex.guest_SP;

   if (!isRT)
      size = restore_sigframe(tst, (struct sigframe *)sp, &sigNo);
   else
      size = restore_rt_sigframe(tst, (struct rt_sigframe *)sp, &sigNo);

   /* same as for creation: we must announce the full memory (including
      alignment), otherwise massif might fail on longjmp */
   VG_TRACK( die_mem_stack_signal, sp - VG_STACK_REDZONE_SZB,
             size + VG_STACK_REDZONE_SZB );

   if (VG_(clo_trace_signals))
      VG_(message)(
         Vg_DebugMsg,
         "VG_(sigframe_destroy) (thread %u): isRT=%d valid magic; IP=%#llx\n",
         tid, isRT, tst->arch.vex.guest_IA);

   /* tell the tools */
   VG_TRACK( post_deliver_signal, tid, sigNo );
}

void VG_(sigframe_destroy)( ThreadId tid )
{
   Addr          rsp;
   ThreadState*  tst;
   SizeT	 size;
   Int		 sigNo;

   tst = VG_(get_ThreadState)(tid);

   /* Correctly reestablish the frame base address. */
   rsp   = tst->arch.vex.guest_RSP;

   size = restore_sigframe(tst, (struct sigframe *)rsp, &sigNo);

   VG_TRACK( die_mem_stack_signal, rsp - VG_STACK_REDZONE_SZB,
             size + VG_STACK_REDZONE_SZB );

   if (VG_(clo_trace_signals))
      VG_(message)(
         Vg_DebugMsg, 
         "VG_(signal_return) (thread %d): valid magic; RIP=%#llx\n",
         tid, tst->arch.vex.guest_RIP);

   /* tell the tools */
   VG_TRACK( post_deliver_signal, tid, sigNo );
}

static
void startup_segment_callback ( Addr start, UInt size, 
                                Char rr, Char ww, Char xx, 
                                UInt foffset, UChar* filename )
{
   UInt r_esp;
   Bool is_stack_segment;
   Bool verbose = False; /* set to True for debugging */

   if (verbose)
      VG_(message)(Vg_DebugMsg,
                   "initial map %8x-%8x %c%c%c? %8x (%d) (%s)",
                   start,start+size,rr,ww,xx,foffset,
                   size, filename?filename:(UChar*)"NULL");

   if (rr != 'r' && xx != 'x' && ww != 'w') {
      /* Implausible as it seems, R H 6.2 generates such segments:
      40067000-400ac000 r-xp 00000000 08:05 320686 /usr/X11R6/lib/libXt.so.6.0
      400ac000-400ad000 ---p 00045000 08:05 320686 /usr/X11R6/lib/libXt.so.6.0
      400ad000-400b0000 rw-p 00045000 08:05 320686 /usr/X11R6/lib/libXt.so.6.0
      when running xedit. So just ignore them. */
      if (0)
         VG_(printf)("No permissions on a segment mapped from %s\n", 
                     filename?filename:(UChar*)"NULL");
      return;
   }

   /* If this segment corresponds to something mmap'd /dev/zero by the
      low-level memory manager (vg_malloc2.c), skip it.  Clients
      should never have access to the segments which hold valgrind
      internal data.  And access to client data in the VG_AR_CLIENT
      arena is mediated by the skin, so we don't want make it
      accessible at this stage. */
   if (VG_(is_inside_segment_mmapd_by_low_level_MM)( start )) {
      if (verbose)
         VG_(message)(Vg_DebugMsg,
                      "   skipping %8x-%8x (owned by our MM)", 
                      start, start+size );
      /* Don't announce it to the skin. */
      return;
   }
   
   /* This parallels what happens when we mmap some new memory */
   if (filename != NULL && xx == 'x') {
      VG_(new_exe_segment)( start, size );
   }

   VG_TRACK( new_mem_startup, start, size, rr=='r', ww=='w', xx=='x' );

   /* If this is the stack segment mark all below %esp as noaccess. */
   r_esp = VG_(baseBlock)[VGOFF_(m_esp)];
   is_stack_segment = start <= r_esp && r_esp < start+size;
   if (is_stack_segment) {
      if (0)
         VG_(message)(Vg_DebugMsg, "invalidating stack area: %x .. %x",
                      start,r_esp);
      VG_TRACK( die_mem_stack, start, r_esp-start );
   }
}

static 
void stack_mcontext ( struct vki_mcontext *mc, 
                      ThreadState* tst, 
                      Bool use_rt_sigreturn,
                      UInt fault_addr )
{
   VG_TRACK( pre_mem_write, Vg_CoreSignal, tst->tid, "signal frame mcontext",
             (Addr)mc, sizeof(struct vki_pt_regs) );

#  define DO(gpr)  mc->mc_gregs[VKI_PT_R0+gpr] = tst->arch.vex.guest_GPR##gpr
   DO(0);  DO(1);  DO(2);  DO(3);  DO(4);  DO(5);  DO(6);  DO(7);
   DO(8);  DO(9);  DO(10); DO(11); DO(12); DO(13); DO(14); DO(15);
   DO(16); DO(17); DO(18); DO(19); DO(20); DO(21); DO(22); DO(23);
   DO(24); DO(25); DO(26); DO(27); DO(28); DO(29); DO(30); DO(31);
#  undef DO

   mc->mc_gregs[VKI_PT_NIP]     = tst->arch.vex.guest_CIA;
   mc->mc_gregs[VKI_PT_MSR]     = 0xf032;   /* pretty arbitrary */
   mc->mc_gregs[VKI_PT_ORIG_R3] = tst->arch.vex.guest_GPR3;
   mc->mc_gregs[VKI_PT_CTR]     = tst->arch.vex.guest_CTR;
   mc->mc_gregs[VKI_PT_LNK]     = tst->arch.vex.guest_LR;
   mc->mc_gregs[VKI_PT_XER]     = LibVEX_GuestPPC32_get_XER(&tst->arch.vex);
   mc->mc_gregs[VKI_PT_CCR]     = LibVEX_GuestPPC32_get_CR(&tst->arch.vex);
   mc->mc_gregs[VKI_PT_MQ]      = 0;
   mc->mc_gregs[VKI_PT_TRAP]    = 0;
   mc->mc_gregs[VKI_PT_DAR]     = fault_addr;
   mc->mc_gregs[VKI_PT_DSISR]   = 0;
   mc->mc_gregs[VKI_PT_RESULT]  = 0;
   VG_TRACK( post_mem_write, Vg_CoreSignal, tst->tid, 
             (Addr)mc, sizeof(struct vki_pt_regs) );

   /* XXX should do FP and vector regs */

   /* set up signal return trampoline */
   /* NB.  5 Sept 07.  mc->mc_pad[0..1] used to contain a the code to
      which the signal handler returns, and it just did sys_sigreturn
      or sys_rt_sigreturn.  But this doesn't work if the stack is
      non-executable, and it isn't consistent with the x86-linux and
      amd64-linux scheme for removing the stack frame.  So instead be
      consistent and use a stub in m_trampoline.  Then it doesn't
      matter whether or not the (guest) stack is executable.  This
      fixes #149519 and #145837. */
   VG_TRACK(pre_mem_write, Vg_CoreSignal, tst->tid, "signal frame mcontext",
            (Addr)&mc->mc_pad, sizeof(mc->mc_pad));
   mc->mc_pad[0] = 0; /* invalid */
   mc->mc_pad[1] = 0; /* invalid */
   VG_TRACK( post_mem_write,  Vg_CoreSignal, tst->tid, 
             (Addr)&mc->mc_pad, sizeof(mc->mc_pad) );
   /* invalidate any translation of this area */
   VG_(discard_translations)( (Addr)&mc->mc_pad, 
                              sizeof(mc->mc_pad), "stack_mcontext" );   

   /* set the signal handler to return to the trampoline */
   SET_SIGNAL_LR(tst, (Addr)(use_rt_sigreturn 
                               ? (Addr)&VG_(ppc32_linux_SUBST_FOR_rt_sigreturn)
                               : (Addr)&VG_(ppc32_linux_SUBST_FOR_sigreturn)
                      ));
}

void VG_(unknown_SP_update)( Addr old_SP, Addr new_SP, UInt ecu )
{
   static Int moans = 3;
   Word delta  = (Word)new_SP - (Word)old_SP;

   /* Check if the stack pointer is still in the same stack as before. */
   if (current_stack == NULL ||
       new_SP < current_stack->start || new_SP > current_stack->end) {
      Stack* new_stack = find_stack_by_addr(new_SP);
      if (new_stack 
          && (current_stack == NULL || new_stack->id != current_stack->id)) { 
         /* The stack pointer is now in another stack.  Update the current
            stack information and return without doing anything else. */
         current_stack = new_stack;
         return;
      }
   }

   if (delta < -VG_(clo_max_stackframe) || VG_(clo_max_stackframe) < delta) {
      /* SP has changed by more than some threshold amount (by
         default, 2MB).  We take this to mean that the application is
         switching to a new stack, for whatever reason.
       
         JRS 20021001: following discussions with John Regehr, if a stack
         switch happens, it seems best not to mess at all with memory
         permissions.  Seems to work well with Netscape 4.X.  Really the
         only remaining difficulty is knowing exactly when a stack switch is
         happening. */
      if (VG_(clo_verbosity) > 0 && moans > 0) {
         moans--;
         VG_(message)(Vg_UserMsg,
            "Warning: client switching stacks?  "
            "SP change: %p --> %p", old_SP, new_SP);
         VG_(message)(Vg_UserMsg,
            "         to suppress, use: --max-stackframe=%ld or greater",
            (delta < 0 ? -delta : delta));
         if (moans == 0)
            VG_(message)(Vg_UserMsg,
                "         further instances of this message "
                "will not be shown.");
      }
   } else if (delta < 0) {
      VG_TRACK( new_mem_stack_w_ECU, new_SP, -delta, ecu );
      VG_TRACK( new_mem_stack,       new_SP, -delta );

   } else if (delta > 0) {
      VG_TRACK( die_mem_stack, old_SP,  delta );
   }
}

static Bool extend ( ThreadState *tst, Addr addr, SizeT size )
{
   ThreadId        tid = tst->tid;
   NSegment const* stackseg = NULL;

   if (VG_(extend_stack)(addr, tst->client_stack_szB)) {
      stackseg = VG_(am_find_nsegment)(addr);
      if (0 && stackseg)
	 VG_(printf)("frame=%#lx seg=%#lx-%#lx\n",
		     addr, stackseg->start, stackseg->end);
   }

   if (stackseg == NULL || !stackseg->hasR || !stackseg->hasW) {
      VG_(message)(
         Vg_UserMsg,
         "Can't extend stack to %#lx during signal delivery for thread %d:\n",
         addr, tid);
      if (stackseg == NULL)
         VG_(message)(Vg_UserMsg, "  no stack segment\n");
      else
         VG_(message)(Vg_UserMsg, "  too small or bad protection modes\n");

      
      VG_(set_default_handler)(VKI_SIGSEGV);
      VG_(synth_fault_mapping)(tid, addr);

      return False;
   }

   VG_TRACK( new_mem_stack_signal, addr - VG_STACK_REDZONE_SZB,
             size + VG_STACK_REDZONE_SZB, tid );

   return True;
}

static Bool extend ( ThreadState *tst, Addr addr, SizeT size )
{
   ThreadId tid = tst->tid;
   VG_TRACK( new_mem_stack_signal,
             addr - VG_STACK_REDZONE_SZB, size, tid );
   return True;
}

/* EXPORTED */
void VG_(sigframe_create)( ThreadId tid,
			   Addr sp_top_of_frame,
			   const vki_siginfo_t *siginfo,
			   const struct vki_ucontext *siguc,
			   void *handler,
			   UInt flags,
			   const vki_sigset_t *mask,
			   void *restorer )
{
   Addr sp;
   ThreadState* tst = VG_(get_ThreadState)(tid);

   if (flags & VKI_SA_SIGINFO)
      sp = build_rt_sigframe(tst, sp_top_of_frame, siginfo, siguc,
			     flags, mask, restorer);
   else
      sp = build_sigframe(tst, sp_top_of_frame, siginfo, siguc,
			  flags, mask, restorer);

   /* Set the thread so it will next run the handler. */
   VG_(set_SP)(tid, sp);
   VG_TRACK( post_reg_write, Vg_CoreSignal, tid, VG_O_STACK_PTR, sizeof(Addr));

   tst->arch.vex.guest_IA = (Addr) handler;
   /* We might have interrupted a repeating instruction that uses the guest
      counter. Since our VEX requires that a new instruction will see a
      guest counter == 0, we have to set it here. The old value will be
      restored by restore_vg_sigframe. */
   tst->arch.vex.guest_counter = 0;
   /* This thread needs to be marked runnable, but we leave that the
      caller to do. */
}

/* EXPORTED */
void VG_(sigframe_create)( ThreadId tid, 
                           Addr esp_top_of_frame,
                           const vki_siginfo_t *siginfo,
                           const struct vki_ucontext *siguc,
                           void *handler, 
                           UInt flags,
                           const vki_sigset_t *mask,
		           void *restorer )
{
   Addr		esp;
   ThreadState* tst = VG_(get_ThreadState)(tid);

   if (flags & VKI_SA_SIGINFO)
      esp = build_rt_sigframe(tst, esp_top_of_frame, siginfo, siguc,
                                   handler, flags, mask, restorer);
   else
      esp = build_sigframe(tst, esp_top_of_frame, siginfo, siguc,
                                handler, flags, mask, restorer);

   /* Set the thread so it will next run the handler. */
   /* tst->m_esp  = esp;  also notify the tool we've updated ESP */
   VG_(set_SP)(tid, esp);
   VG_TRACK( post_reg_write, Vg_CoreSignal, tid, VG_O_STACK_PTR, sizeof(Addr));

   //VG_(printf)("handler = %p\n", handler);
   tst->arch.vex.guest_EIP = (Addr) handler;
   /* This thread needs to be marked runnable, but we leave that the
      caller to do. */

   if (0)
      VG_(printf)("pushed signal frame; %%ESP now = %#lx, "
                  "next %%EIP = %#x, status=%d\n",
		  esp, tst->arch.vex.guest_EIP, tst->status);
}

static 
void stack_mcontext ( struct vki_mcontext *mc, 
                      ThreadState* tst, 
                      Int ret,
                      UInt fault_addr )
{
   VG_TRACK( pre_mem_write, Vg_CoreSignal, tst->tid, "signal frame mcontext",
             (Addr)mc, sizeof(struct vki_pt_regs) );

#  define DO(gpr)  mc->mc_gregs[VKI_PT_R0+gpr] = tst->arch.vex.guest_GPR##gpr
   DO(0);  DO(1);  DO(2);  DO(3);  DO(4);  DO(5);  DO(6);  DO(7);
   DO(8);  DO(9);  DO(10); DO(11); DO(12); DO(13); DO(14); DO(15);
   DO(16); DO(17); DO(18); DO(19); DO(20); DO(21); DO(22); DO(23);
   DO(24); DO(25); DO(26); DO(27); DO(28); DO(29); DO(30); DO(31);
#  undef DO

   mc->mc_gregs[VKI_PT_NIP]     = tst->arch.vex.guest_CIA;
   mc->mc_gregs[VKI_PT_MSR]     = 0xf032;   /* pretty arbitrary */
   mc->mc_gregs[VKI_PT_ORIG_R3] = tst->arch.vex.guest_GPR3;
   mc->mc_gregs[VKI_PT_CTR]     = tst->arch.vex.guest_CTR;
   mc->mc_gregs[VKI_PT_LNK]     = tst->arch.vex.guest_LR;
   mc->mc_gregs[VKI_PT_XER]     = LibVEX_GuestPPC32_get_XER(&tst->arch.vex);
   mc->mc_gregs[VKI_PT_CCR]     = LibVEX_GuestPPC32_get_CR(&tst->arch.vex);
   mc->mc_gregs[VKI_PT_MQ]      = 0;
   mc->mc_gregs[VKI_PT_TRAP]    = 0;
   mc->mc_gregs[VKI_PT_DAR]     = fault_addr;
   mc->mc_gregs[VKI_PT_DSISR]   = 0;
   mc->mc_gregs[VKI_PT_RESULT]  = 0;
   VG_TRACK( post_mem_write, Vg_CoreSignal, tst->tid, 
             (Addr)mc, sizeof(struct vki_pt_regs) );

   /* XXX should do FP and vector regs */

   /* set up signal return trampoline */
   VG_TRACK(pre_mem_write, Vg_CoreSignal, tst->tid, "signal frame mcontext",
            (Addr)&mc->mc_pad, sizeof(mc->mc_pad));
   mc->mc_pad[0] = 0x38000000U + ret;   /* li 0,ret */
   mc->mc_pad[1] = 0x44000002U;         /* sc */
   VG_TRACK( post_mem_write,  Vg_CoreSignal, tst->tid, 
             (Addr)&mc->mc_pad, sizeof(mc->mc_pad) );
   /* invalidate any translation of this area */
   VG_(discard_translations)( (Addr64)(Addr)&mc->mc_pad, 
                              sizeof(mc->mc_pad), "stack_mcontext" );   

   /* set the signal handler to return to the trampoline */
   SET_SIGNAL_LR(tst, (Addr) &mc->mc_pad[0]);
}

/* EXPORTED */
void VG_(sigframe_create)( ThreadId tid, 
                           Bool on_altstack,
                           Addr sp_top_of_frame,
                           const vki_siginfo_t *siginfo,
                           const struct vki_ucontext *siguc,
                           void *handler, 
                           UInt flags,
                           const vki_sigset_t *mask,
                           void *restorer )
{
   ThreadState *tst;
   Addr sp    = sp_top_of_frame;
   Int  sigNo = siginfo->si_signo;
   UInt size;

   tst = VG_(get_ThreadState)(tid);

   size = sizeof(struct rt_sigframe);

   sp -= size;
   sp = VG_ROUNDDN(sp, 16);

   if (! ML_(sf_maybe_extend_stack)(tst, sp, size, flags))
      return; // Give up.  No idea if this is correct

   struct rt_sigframe *rsf = (struct rt_sigframe *)sp;
      
   /* Track our writes to siginfo */
   VG_TRACK( pre_mem_write, Vg_CoreSignal, tst->tid,  /* VVVVV */
             "signal handler siginfo", (Addr)rsf, 
             offsetof(struct rt_sigframe, sig));

   VG_(memcpy)(&rsf->info, siginfo, sizeof(vki_siginfo_t));

   if (sigNo == VKI_SIGILL && siginfo->si_code > 0) {
      rsf->info._sifields._sigfault._addr
        = (Addr*)(tst)->arch.vex.guest_PC;
   }
   VG_TRACK( post_mem_write, Vg_CoreSignal, tst->tid, /* ^^^^^ */
         (Addr)rsf, offsetof(struct rt_sigframe, sig));

   build_sigframe(tst, &rsf->sig, siginfo, siguc,
                       handler, flags, mask, restorer);
   tst->arch.vex.guest_X1 = (Addr)&rsf->info;
   tst->arch.vex.guest_X2 = (Addr)&rsf->sig.uc;

   VG_(set_SP)(tid, sp);
   VG_TRACK( post_reg_write, Vg_CoreSignal, tid, VG_O_STACK_PTR,
             sizeof(Addr));
   tst->arch.vex.guest_X0 = sigNo; 

   if (flags & VKI_SA_RESTORER)
       tst->arch.vex.guest_X30 = (Addr)restorer; 
   else
       tst->arch.vex.guest_X30
          = (Addr)&VG_(arm64_linux_SUBST_FOR_rt_sigreturn);

   tst->arch.vex.guest_PC = (Addr)handler;
}