Index: mozilla/xpcom/reflect/xptcall/src/md/unix/xptcinvoke_arm.cpp
===================================================================
--- mozilla.orig/xpcom/reflect/xptcall/src/md/unix/xptcinvoke_arm.cpp	2009-06-25 11:12:00.000000000 -0400
+++ mozilla/xpcom/reflect/xptcall/src/md/unix/xptcinvoke_arm.cpp	2009-06-25 11:32:55.000000000 -0400
@@ -43,6 +43,17 @@
 #error "This code is for Linux ARM only. Check that it works on your system, too.\nBeware that this code is highly compiler dependent."
 #endif
 
+/* Note that we give a "worst case" estimate of how much stack _might_ be
+* needed (for __ARM_EABI__), rather than the real count - this should be safe */
+
+#ifdef __ARM_EABI__
+#define DOUBLEWORD_ALIGN(p) ((PRUint32 *)((((PRUint32)(p)) + 7) & 0xfffffff8))
+#define VAR_STACK_SIZE_64 3
+#else
+#define DOUBLEWORD_ALIGN(p) (p)
+#define VAR_STACK_SIZE_64 2
+#endif
+
 // Remember that these 'words' are 32bit DWORDS
 
 static PRUint32
@@ -64,7 +75,7 @@
             result++;
             break;
         case nsXPTType::T_I64    :
-            result+=2;
+            result+=VAR_STACK_SIZE_64;
             break;
         case nsXPTType::T_U8     :
         case nsXPTType::T_U16    :
@@ -72,13 +83,13 @@
             result++;
             break;
         case nsXPTType::T_U64    :
-            result+=2;
+            result+=VAR_STACK_SIZE_64 ;
             break;
         case nsXPTType::T_FLOAT  :
             result++;
             break;
         case nsXPTType::T_DOUBLE :
-            result+=2;
+            result+=VAR_STACK_SIZE_64 ;
             break;
         case nsXPTType::T_BOOL   :
         case nsXPTType::T_CHAR   :
@@ -91,6 +102,15 @@
             break;
         }
     }
+
+#ifdef __ARM_EABI__
+    /* Ensure stack is always aligned to doubleword boundary; we take 3 words
+     * off the stack to r1-r3 later, so it must always be on _odd_ word 
+     * boundary after this */
+    if (result % 2 == 0)
+        result++;
+#endif
+
     return result;
 }
 
@@ -109,13 +129,16 @@
         case nsXPTType::T_I8     : *((PRInt8*)  d) = s->val.i8;          break;
         case nsXPTType::T_I16    : *((PRInt16*) d) = s->val.i16;         break;
         case nsXPTType::T_I32    : *((PRInt32*) d) = s->val.i32;         break;
-        case nsXPTType::T_I64    : *((PRInt64*) d) = s->val.i64; d++;    break;
+        case nsXPTType::T_I64    : d = DOUBLEWORD_ALIGN(d);
+                                   *((PRInt64*) d) = s->val.i64; d++;    break;
         case nsXPTType::T_U8     : *((PRUint8*) d) = s->val.u8;          break;
         case nsXPTType::T_U16    : *((PRUint16*)d) = s->val.u16;         break;
         case nsXPTType::T_U32    : *((PRUint32*)d) = s->val.u32;         break;
-        case nsXPTType::T_U64    : *((PRUint64*)d) = s->val.u64; d++;    break;
+        case nsXPTType::T_U64    : d = DOUBLEWORD_ALIGN(d);
+                                   *((PRUint64*)d) = s->val.u64; d++;    break;
         case nsXPTType::T_FLOAT  : *((float*)   d) = s->val.f;           break;
-        case nsXPTType::T_DOUBLE : *((double*)  d) = s->val.d;   d++;    break;
+        case nsXPTType::T_DOUBLE : d = DOUBLEWORD_ALIGN(d);
+                                   *((double*)  d) = s->val.d;   d++;    break;
         case nsXPTType::T_BOOL   : *((PRBool*)  d) = s->val.b;           break;
         case nsXPTType::T_CHAR   : *((char*)    d) = s->val.c;           break;
         case nsXPTType::T_WCHAR  : *((wchar_t*) d) = s->val.wc;          break;