Commit: ARM SIM

Commit: ARM SIM

[Nick Clifton]

Hi Guys,

  I have been testing the ARM simulator against various illegal binaries
  and I have come across a couple of small problems.  The first is that
  the sim will complain about illegal arguments to the 64-bit multiply
  instructions (good), but it will complain even if the user does not
  want to see the complaints (bad).  So I have added code to restrict
  the error messages to when debugging is enabled.

  The second fix is to the SWIopen() function, which used to assume that
  the flags provided in register r1 were always valid.  This patch adds
  code to check the flags, and ignore invalid ones.

Cheers
  Nick

sim/arm/ChangeLog
2016-07-14  Nick Clifton  <nickc@redhat.com>

	* armemu.c (Multiply64): Only issue error messages about invalid
	arguments if debugging is enabled.
	* armos.c (ARMul_OSHandleSWI): Ignore invalid flags.  

diff --git a/sim/arm/armemu.c b/sim/arm/armemu.c
index 5fde3fd..76f398b 100644
--- a/sim/arm/armemu.c
+++ b/sim/arm/armemu.c
@@ -5950,10 +5950,10 @@ Multiply64 (ARMul_State * state, ARMword instr, int msigned, int scc)
 	;
       else
 #endif
-	if (nRdHi == nRm || nRdLo == nRm)
+	/* BAD code can trigger this result.  So only complain if debugging.  */
+	if (state->Debug && (nRdHi == nRm || nRdLo == nRm))
 	  fprintf (stderr, "sim: MULTIPLY64 - INVALID ARGUMENTS: %d %d %d\n",
 		   nRdHi, nRdLo, nRm);
-
       if (msigned)
 	{
 	  /* Compute sign of result and adjust operands if necessary.  */
@@ -5998,7 +5998,7 @@ Multiply64 (ARMul_State * state, ARMword instr, int msigned, int scc)
       state->Reg[nRdLo] = RdLo;
       state->Reg[nRdHi] = RdHi;
     }
-  else
+  else if (state->Debug)
     fprintf (stderr, "sim: MULTIPLY64 - INVALID ARGUMENTS\n");
 
   if (scc)
diff --git a/sim/arm/armos.c b/sim/arm/armos.c
index c49036f..ea3d229 100644
--- a/sim/arm/armos.c
+++ b/sim/arm/armos.c
@@ -260,7 +260,10 @@ SWIopen (ARMul_State * state, ARMword name, ARMword SWIflags)
     return;
 
   /* Now we need to decode the Demon open mode.  */
-  flags = translate_open_mode[SWIflags];
+  if (SWIflags >= sizeof (translate_open_mode) / sizeof (translate_open_mode[0]))
+    flags = 0;
+  else
+    flags = translate_open_mode[SWIflags];
 
   /* Filename ":tt" is special: it denotes stdin/out.  */
   if (strcmp (buf, ":tt") == 0)