Re: sim/arm/armos.c: IsTTY [PATCH]

[Shaun Jackman <sjackman at gmail dot com>]

2005/9/8, Richard Earnshaw <rearnsha@gcc.gnu.org>:
> Two problems I can immediately see with this.
> 
> 1) PATH_MAX isn't ANSI (it's POSIX, or something like that).  So you
> can't rely on it being defined.  I think for this case you can probably
> just define it to 1024 anyway if it's missing, but see
> libiberty/lrealpath.c if you want the gory details.
> 
> 2) If you do overflow the path limit, you need to set the simulator's
> errno value and return.  Use cb_host_to_target_errno(sim_callback,
> ENAMETOOLONG) to set it.
> 
> R.

I've changed PATH_MAX from POSIX to FILENAME_MAX from ANSI and checked
if the path limit overflowed.

Cheers,
Shaun

2005-09-09  Shaun Jackman  <sjackman@gmail.com>

	* sim/arm/armos.c (unlink): Remove this macro. It is unused
	in this file and conflicts with sim_callback->unlink.
	(SWIopen): Fix a potential buffer overflow.
	(SWIremove): New function.
	(SWIrename): Ditto.
	(ARMul_OSHandleSWI): Handle the RDP calls SWI_IsTTY,
	SWI_Remove, and SWI_Rename, as well as the RDI calls
	AngelSWI_Reason_IsTTY, AngelSWI_Reason_Remove, and
	AngelSWI_Reason_Rename.

Index: sim/arm/armos.c
===================================================================
RCS file: /cvs/src/src/sim/arm/armos.c,v
retrieving revision 1.22
diff -u -r1.22 armos.c
--- sim/arm/armos.c	12 May 2005 07:36:58 -0000	1.22
+++ sim/arm/armos.c	9 Sep 2005 17:19:08 -0000
@@ -27,6 +27,7 @@
 
 #include <time.h>
 #include <errno.h>
+#include <limits.h>
 #include <string.h>
 #include "targ-vals.h"
 
@@ -34,10 +35,6 @@
 #define TARGET_O_BINARY 0
 #endif
 
-#ifdef __STDC__
-#define unlink(s) remove(s)
-#endif
-
 #ifdef HAVE_UNISTD_H
 #include <unistd.h>		/* For SEEK_SET etc.  */
 #endif
@@ -303,18 +300,24 @@
 SWIopen (ARMul_State * state, ARMword name, ARMword SWIflags)
 {
   struct OSblock *OSptr = (struct OSblock *) state->OSptr;
-  char dummy[2000];
+  char buf[FILENAME_MAX], *p = buf;
   int flags;
   int i;
 
-  for (i = 0; (dummy[i] = ARMul_SafeReadByte (state, name + i)); i++)
-    ;
+  for (i = 0; i < sizeof buf; i++)
+    if ((*p++ = ARMul_SafeReadByte (state, name++)) == '\0')
+      break;
+  if (i == sizeof buf) {
+    state->Reg[0] = -1;
+    OSptr->ErrorNo = cb_host_to_target_errno(sim_callback, ENAMETOOLONG);
+    return;
+  }
 
   /* Now we need to decode the Demon open mode.  */
   flags = translate_open_mode[SWIflags];
 
   /* Filename ":tt" is special: it denotes stdin/out.  */
-  if (strcmp (dummy, ":tt") == 0)
+  if (strcmp (buf, ":tt") == 0)
     {
       if (flags == TARGET_O_RDONLY) /* opening tty "r" */
 	state->Reg[0] = 0;	/* stdin */
@@ -323,7 +326,7 @@
     }
   else
     {
-      state->Reg[0] = sim_callback->open (sim_callback, dummy, flags);
+      state->Reg[0] = sim_callback->open (sim_callback, buf, flags);
       OSptr->ErrorNo = sim_callback->get_errno (sim_callback);
     }
 }
@@ -403,6 +406,54 @@
   OSptr->ErrorNo = sim_callback->get_errno (sim_callback);
 }
 
+static void
+SWIremove (ARMul_State * state, ARMword path)
+{
+  struct OSblock *OSptr = (struct OSblock *) state->OSptr;
+  char buf[FILENAME_MAX], *p = buf;
+  int i;
+
+  for (i = 0; i < sizeof buf; i++)
+    if ((*p++ = ARMul_SafeReadByte (state, path++)) == '\0')
+      break;
+  if (i == sizeof buf) {
+    state->Reg[0] = -1;
+    OSptr->ErrorNo = cb_host_to_target_errno(sim_callback, ENAMETOOLONG);
+    return;
+  }
+
+  state->Reg[0] = sim_callback->unlink (sim_callback, buf);
+  OSptr->ErrorNo = sim_callback->get_errno (sim_callback);
+}
+
+static void
+SWIrename (ARMul_State * state, ARMword old, ARMword new)
+{
+  struct OSblock *OSptr = (struct OSblock *) state->OSptr;
+  char oldbuf[FILENAME_MAX], newbuf[FILENAME_MAX], *p;
+  int i;
+
+  for (p = oldbuf, i = 0; i < sizeof oldbuf; i++)
+    if ((*p++ = ARMul_SafeReadByte (state, old++)) == '\0')
+      break;
+  if (i == sizeof oldbuf) {
+    state->Reg[0] = -1;
+    OSptr->ErrorNo = cb_host_to_target_errno(sim_callback, ENAMETOOLONG);
+    return;
+  }
+  for (p = newbuf, i = 0; i < sizeof newbuf; i++)
+    if ((*p++ = ARMul_SafeReadByte (state, new++)) == '\0')
+      break;
+  if (i == sizeof newbuf) {
+    state->Reg[0] = -1;
+    OSptr->ErrorNo = cb_host_to_target_errno(sim_callback, ENAMETOOLONG);
+    return;
+  }
+
+  state->Reg[0] = sim_callback->rename (sim_callback, oldbuf, newbuf);
+  OSptr->ErrorNo = sim_callback->get_errno (sim_callback);
+}
+
 /* The emulator calls this routine when a SWI instruction is encuntered.
    The parameter passed is the SWI number (lower 24 bits of the
instruction).  */
 
@@ -544,6 +595,30 @@
       state->Emulate = FALSE;
       break;
 
+    case SWI_Remove:
+      if (swi_mask & SWI_MASK_DEMON)
+	SWIremove (state, state->Reg[0]);
+      else
+	unhandled = TRUE;
+      break;
+
+    case SWI_Rename:
+      if (swi_mask & SWI_MASK_DEMON)
+	SWIrename (state, state->Reg[0], state->Reg[1]);
+      else
+	unhandled = TRUE;
+      break;
+
+    case SWI_IsTTY:
+      if (swi_mask & SWI_MASK_DEMON)
+	{
+	  state->Reg[0] = sim_callback->isatty (sim_callback, state->Reg[0]);
+	  OSptr->ErrorNo = sim_callback->get_errno (sim_callback);
+	}
+      else
+	unhandled = TRUE;
+      break;
+
       /* Handle Angel SWIs as well as Demon ones.  */
     case AngelSWI_ARM:
     case AngelSWI_Thumb:
@@ -566,10 +641,7 @@
 	  
 	      /* Unimplemented reason codes.  */
 	    case AngelSWI_Reason_ReadC:
-	    case AngelSWI_Reason_IsTTY:
 	    case AngelSWI_Reason_TmpNam:
-	    case AngelSWI_Reason_Remove:
-	    case AngelSWI_Reason_Rename:
 	    case AngelSWI_Reason_System:
 	    case AngelSWI_Reason_EnterSVC:
 	    default:
@@ -684,6 +756,21 @@
 			ARMul_ReadWord (state, addr + 4),
 			ARMul_ReadWord (state, addr + 8));
 	      break;
+
+	    case AngelSWI_Reason_IsTTY:
+	      state->Reg[0] = sim_callback->close (sim_callback,
+						   ARMul_ReadWord (state, addr));
+	      OSptr->ErrorNo = sim_callback->get_errno (sim_callback);
+	      break;
+
+	    case AngelSWI_Reason_Remove:
+	      SWIremove (state,
+			 ARMul_ReadWord (state, addr));
+
+	    case AngelSWI_Reason_Rename:
+	      SWIrename (state,
+			 ARMul_ReadWord (state, addr),
+			 ARMul_ReadWord (state, addr + 4));
 	    }
 	}
       else

Attachment: sim-arm-swi.diff
Description: Text document