* s390-tdep.c (s390_push_dummy_call): Error on stack overflow

	during inferior call stack frame setup.

2 files changed, 24 insertions, 9 deletions

diff --git a/gdb/ChangeLog b/gdb/ChangeLog
index 0a16ed6..c696b6d 100644
--- a/gdb/ChangeLog
+++ b/gdb/ChangeLog
@@ -1,3 +1,8 @@
+2010-06-25  Ulrich Weigand  <uweigand@de.ibm.com>
+
+	* s390-tdep.c (s390_push_dummy_call): Error on stack overflow
+	during inferior call stack frame setup.
+
 2010-06-25  Ken Werner  <ken.werner@de.ibm.com>
 
 	* solib-spu.c: Include "exception.h".
diff --git a/gdb/s390-tdep.c b/gdb/s390-tdep.c
index e7dc48d..daeed0d 100644
--- a/gdb/s390-tdep.c
+++ b/gdb/s390-tdep.c
@@ -2343,14 +2343,13 @@ s390_push_dummy_call (struct gdbarch *gdbarch, struct value *function,
   struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
   int word_size = gdbarch_ptr_bit (gdbarch) / 8;
   enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
-  ULONGEST orig_sp;
   int i;
 
   /* If the i'th argument is passed as a reference to a copy, then
      copy_addr[i] is the address of the copy we made.  */
   CORE_ADDR *copy_addr = alloca (nargs * sizeof (CORE_ADDR));
 
-  /* Build the reference-to-copy area.  */
+  /* Reserve space for the reference-to-copy area.  */
   for (i = 0; i < nargs; i++)
     {
       struct value *arg = args[i];
@@ -2361,7 +2360,6 @@ s390_push_dummy_call (struct gdbarch *gdbarch, struct value *function,
         {
           sp -= length;
           sp = align_down (sp, alignment_of (type));
-          write_memory (sp, value_contents (arg), length);
           copy_addr[i] = sp;
         }
     }
@@ -2376,13 +2374,26 @@ s390_push_dummy_call (struct gdbarch *gdbarch, struct value *function,
      boundary.  */
   sp = align_down (sp, 8);
 
+  /* Allocate the standard frame areas: the register save area, the
+     word reserved for the compiler (which seems kind of meaningless),
+     and the back chain pointer.  */
+  sp -= 16*word_size + 32;
+
+  /* Now we have the final SP value.  Make sure we didn't underflow;
+     on 31-bit, this would result in addresses with the high bit set,
+     which causes confusion elsewhere.  Note that if we error out
+     here, stack and registers remain untouched.  */
+  if (gdbarch_addr_bits_remove (gdbarch, sp) != sp)
+    error (_("Stack overflow"));
+
+
   /* Finally, place the actual parameters, working from SP towards
      higher addresses.  The code above is supposed to reserve enough
      space for this.  */
   {
     int fr = 0;
     int gr = 2;
-    CORE_ADDR starg = sp;
+    CORE_ADDR starg = sp + 16*word_size + 32;
 
     /* A struct is returned using general register 2.  */
     if (struct_return)
@@ -2400,6 +2411,10 @@ s390_push_dummy_call (struct gdbarch *gdbarch, struct value *function,
 
 	if (s390_function_arg_pass_by_reference (type))
 	  {
+	    /* Actually copy the argument contents to the stack slot
+	       that was reserved above.  */
+	    write_memory (copy_addr[i], value_contents (arg), length);
+
 	    if (gr <= 6)
 	      {
 		regcache_cooked_write_unsigned (regcache, S390_R0_REGNUM + gr,
@@ -2475,11 +2490,6 @@ s390_push_dummy_call (struct gdbarch *gdbarch, struct value *function,
       }
   }
 
-  /* Allocate the standard frame areas: the register save area, the
-     word reserved for the compiler (which seems kind of meaningless),
-     and the back chain pointer.  */
-  sp -= 16*word_size + 32;
-
   /* Store return address.  */
   regcache_cooked_write_unsigned (regcache, S390_RETADDR_REGNUM, bp_addr);