[project @ 2005-01-28 12:55:17 by simonmar]
[ghc-hetmet.git] / ghc / rts / Adjustor.c
index 3b93989..59119bf 100644 (file)
@@ -34,8 +34,8 @@ An adjustor thunk differs from a C function pointer in one respect: when
 the code is through with it, it has to be freed in order to release Haskell
 and C resources. Failure to do so result in memory leaks on both the C and
 Haskell side.
-
 */
+
 #include "PosixSource.h"
 #include "Rts.h"
 #include "RtsExternal.h"
@@ -46,57 +46,68 @@ Haskell side.
 #include <windows.h>
 #endif
 
-/* Heavily arch-specific, I'm afraid.. */
+#if defined(openbsd_HOST_OS)
+#include <unistd.h>
+#include <sys/types.h>
+#include <sys/mman.h>
 
-typedef enum { 
-    pageExecuteRead, 
-    pageExecuteReadWrite 
-} pageMode;
+/* no C99 header stdint.h on OpenBSD? */
+typedef unsigned long my_uintptr_t;
+#endif
+
+#if defined(powerpc_HOST_ARCH) && defined(linux_HOST_OS)
+#include <string.h>
+#endif
+
+/* Heavily arch-specific, I'm afraid.. */
 
 /*
- * Function: execPage()
- *
- * Set the executable bit on page containing addr.
+ * Allocate len bytes which are readable, writable, and executable.
  *
- * TODO: Can the code span more than one page? If yes, we need to make two
- * pages executable!
+ * ToDo: If this turns out to be a performance bottleneck, one could
+ * e.g. cache the last VirtualProtect/mprotect-ed region and do
+ * nothing in case of a cache hit.
  */
-static void
-execPage (void* addr, pageMode mode)
+static void*
+mallocBytesRWX(int len)
 {
-#if defined(i386_TARGET_ARCH) && defined(_WIN32) && 0
-    SYSTEM_INFO sInfo;
-    DWORD dwOldProtect = 0;
-
-    /* doesn't return a result, so presumably it can't fail... */
-    GetSystemInfo(&sInfo);
-    
-    if ( VirtualProtect ( (void*)((unsigned long)addr & (sInfo.dwPageSize - 1)),
-                         sInfo.dwPageSize,
-                         ( mode == pageExecuteReadWrite ? PAGE_EXECUTE_READWRITE : PAGE_EXECUTE_READ),
-                         &dwOldProtect) == 0 ) {
-       DWORD rc = GetLastError();
-       barf("execPage: failed to protect 0x%p; error=%lu; old protection: %lu\n", addr, rc, dwOldProtect);
-    }
-#else
-    (void)addr;   (void)mode;   /* keep gcc -Wall happy */
+  void *addr = stgMallocBytes(len, "mallocBytesRWX");
+#if defined(i386_HOST_ARCH) && defined(_WIN32)
+  /* This could be necessary for processors which distinguish between READ and
+     EXECUTE memory accesses, e.g. Itaniums. */
+  DWORD dwOldProtect = 0;
+  if (VirtualProtect (addr, len, PAGE_EXECUTE_READWRITE, &dwOldProtect) == 0) {
+    barf("mallocBytesRWX: failed to protect 0x%p; error=%lu; old protection: %lu\n",
+         addr, (unsigned long)GetLastError(), (unsigned long)dwOldProtect);
+  }
+#elif defined(openbsd_HOST_OS)
+  /* malloced memory isn't executable by default on OpenBSD */
+  my_uintptr_t pageSize         = sysconf(_SC_PAGESIZE);
+  my_uintptr_t mask             = ~(pageSize - 1);
+  my_uintptr_t startOfFirstPage = ((my_uintptr_t)addr          ) & mask;
+  my_uintptr_t startOfLastPage  = ((my_uintptr_t)addr + len - 1) & mask;
+  my_uintptr_t size             = startOfLastPage - startOfFirstPage + pageSize;
+  if (mprotect((void*)startOfFirstPage, (size_t)size, PROT_EXEC | PROT_READ | PROT_WRITE) != 0) {
+    barf("mallocBytesRWX: failed to protect 0x%p\n", addr);
+  }
 #endif
+  return addr;
 }
 
-#if defined(i386_TARGET_ARCH)
+#if defined(i386_HOST_ARCH)
 static unsigned char *obscure_ccall_ret_code;
 #endif
 
-#if defined(alpha_TARGET_ARCH)
+#if defined(alpha_HOST_ARCH)
 /* To get the definition of PAL_imb: */
-# if defined(linux_TARGET_OS)
+# if defined(linux_HOST_OS)
 #  include <asm/pal.h>
 # else
 #  include <machine/pal.h>
 # endif
 #endif
 
-#if defined(ia64_TARGET_ARCH)
+#if defined(ia64_HOST_ARCH)
 #include "Storage.h"
 
 /* Layout of a function descriptor */
@@ -127,15 +138,74 @@ stgAllocStable(size_t size_in_bytes, StgStablePtr *stable)
 }
 #endif
 
+#if defined(powerpc_HOST_ARCH) && defined(linux_HOST_OS)
+__asm__("obscure_ccall_ret_code:\n\t"
+        "lwz 1,0(1)\n\t"
+        "lwz 0,4(1)\n\t"
+        "mtlr 0\n\t"
+        "blr");
+extern void obscure_ccall_ret_code(void);
+#endif
+
+#if defined(powerpc_HOST_ARCH) || defined(powerpc64_HOST_ARCH)
+#if !(defined(powerpc_HOST_ARCH) && defined(linux_HOST_OS))
+
+/* !!! !!! WARNING: !!! !!!
+ * This structure is accessed from AdjustorAsm.s
+ * Any changes here have to be mirrored in the offsets there.
+ */
+
+typedef struct AdjustorStub {
+#if defined(powerpc_HOST_ARCH) && defined(darwin_HOST_OS)
+    unsigned        lis;
+    unsigned        ori;
+    unsigned        lwz;
+    unsigned        mtctr;
+    unsigned        bctr;
+    StgFunPtr       code;
+#elif defined(powerpc64_HOST_ARCH) && defined(darwin_HOST_OS)
+        /* powerpc64-darwin: just guessing that it won't use fundescs. */
+    unsigned        lis;
+    unsigned        ori;
+    unsigned        rldimi;
+    unsigned        oris;
+    unsigned        ori2;
+    unsigned        lwz;
+    unsigned        mtctr;
+    unsigned        bctr;
+    StgFunPtr       code;
+#else
+        /* fundesc-based ABIs */
+#define         FUNDESCS
+    StgFunPtr       code;
+    struct AdjustorStub
+                    *toc;
+    void            *env;
+#endif
+    StgStablePtr    hptr;
+    StgFunPtr       wptr;
+    StgInt          negative_framesize;
+    StgInt          extrawords_plus_one;
+} AdjustorStub;
+
+#endif
+#endif
+
 void*
-createAdjustor(int cconv, StgStablePtr hptr, StgFunPtr wptr)
+createAdjustor(int cconv, StgStablePtr hptr,
+              StgFunPtr wptr,
+              char *typeString
+#if !defined(powerpc_HOST_ARCH) && !defined(powerpc64_HOST_ARCH)
+                 STG_UNUSED
+#endif
+              )
 {
   void *adjustor = NULL;
 
   switch (cconv)
   {
   case 0: /* _stdcall */
-#if defined(i386_TARGET_ARCH)
+#if defined(i386_HOST_ARCH)
     /* Magic constant computed by inspecting the code length of
        the following assembly language snippet
        (offset and machine code prefixed):
@@ -148,7 +218,7 @@ createAdjustor(int cconv, StgStablePtr hptr, StgFunPtr wptr)
      <c>:      ff e0             jmp    %eax              # and jump to it.
                # the callee cleans up the stack
     */
-    adjustor = stgMallocBytes(14, "createAdjustor");
+    adjustor = mallocBytesRWX(14);
     {
        unsigned char *const adj_code = (unsigned char *)adjustor;
        adj_code[0x00] = (unsigned char)0x58;  /* popl %eax  */
@@ -163,14 +233,12 @@ createAdjustor(int cconv, StgStablePtr hptr, StgFunPtr wptr)
 
        adj_code[0x0c] = (unsigned char)0xff; /* jmp %eax */
        adj_code[0x0d] = (unsigned char)0xe0;
-       
-       execPage(adjustor, pageExecuteReadWrite);
     }
 #endif
     break;
 
   case 1: /* _ccall */
-#if defined(i386_TARGET_ARCH)
+#if defined(i386_HOST_ARCH)
   /* Magic constant computed by inspecting the code length of
      the following assembly language snippet
      (offset and machine code prefixed):
@@ -195,7 +263,7 @@ createAdjustor(int cconv, StgStablePtr hptr, StgFunPtr wptr)
     That's (thankfully) the case here with the restricted set of 
     return types that we support.
   */
-    adjustor = stgMallocBytes(17, "createAdjustor");
+    adjustor = mallocBytesRWX(17);
     {
        unsigned char *const adj_code = (unsigned char *)adjustor;
 
@@ -210,10 +278,8 @@ createAdjustor(int cconv, StgStablePtr hptr, StgFunPtr wptr)
 
        adj_code[0x0f] = (unsigned char)0xff; /* jmp *%eax */
        adj_code[0x10] = (unsigned char)0xe0; 
-
-       execPage(adjustor, pageExecuteReadWrite);
     }
-#elif defined(sparc_TARGET_ARCH)
+#elif defined(sparc_HOST_ARCH)
   /* Magic constant computed by inspecting the code length of the following
      assembly language snippet (offset and machine code prefixed):
 
@@ -243,7 +309,7 @@ createAdjustor(int cconv, StgStablePtr hptr, StgFunPtr wptr)
      similarly, and local variables should be accessed via %fp, not %sp. In a
      nutshell: This should work! (Famous last words! :-)
   */
-    adjustor = stgMallocBytes(4*(11+1), "createAdjustor");
+    adjustor = mallocBytesRWX(4*(11+1));
     {
         unsigned long *const adj_code = (unsigned long *)adjustor;
 
@@ -278,7 +344,7 @@ createAdjustor(int cconv, StgStablePtr hptr, StgFunPtr wptr)
         asm("nop");
         asm("nop");
     }
-#elif defined(alpha_TARGET_ARCH)
+#elif defined(alpha_HOST_ARCH)
   /* Magic constant computed by inspecting the code length of
      the following assembly language snippet
      (offset and machine code prefixed; note that the machine code
@@ -301,7 +367,7 @@ createAdjustor(int cconv, StgStablePtr hptr, StgFunPtr wptr)
      divided by 4, taking the lowest 14 bits.
 
      We only support passing 4 or fewer argument words, for the same
-     reason described under sparc_TARGET_ARCH above by JRS, 21 Aug 01.
+     reason described under sparc_HOST_ARCH above by JRS, 21 Aug 01.
      On the Alpha the first 6 integer arguments are in a0 through a5,
      and the rest on the stack.  Hence we want to shuffle the original
      caller's arguments by two.
@@ -320,7 +386,7 @@ TODO: Depending on how much allocation overhead stgMallocBytes uses for
       4 bytes (getting rid of the nop), hence saving memory. [ccshan]
   */
     ASSERT(((StgWord64)wptr & 3) == 0);
-    adjustor = stgMallocBytes(48, "createAdjustor");
+    adjustor = mallocBytesRWX(48);
     {
        StgWord64 *const code = (StgWord64 *)adjustor;
 
@@ -336,72 +402,344 @@ TODO: Depending on how much allocation overhead stgMallocBytes uses for
        /* Ensure that instruction cache is consistent with our new code */
        __asm__ volatile("call_pal %0" : : "i" (PAL_imb));
     }
-#elif defined(powerpc_TARGET_ARCH)
-/*
-       For PowerPC, the following code is used:
-
-       mr r10,r8
-       mr r9,r7
-       mr r8,r6
-       mr r7,r5
-       mr r6,r4
-       mr r5,r3
-       lis r0,0xDEAD ;hi(wptr)
-       lis r3,0xDEAF ;hi(hptr)
-       ori r0,r0,0xBEEF ; lo(wptr)
-       ori r3,r3,0xFACE ; lo(hptr)
-       mtctr r0
-       bctr
-
-       The arguments (passed in registers r3 - r10) are shuffled along by two to
-       make room for hptr and a dummy argument. As r9 and r10 are overwritten by
-       this code, it only works for up to 6 arguments (when floating point arguments
-       are involved, this may be more or less, depending on the exact situation).
-*/
-       adjustor = stgMallocBytes(4*13, "createAdjustor");
-       {
-               unsigned long *const adj_code = (unsigned long *)adjustor;
-
-               // make room for extra arguments
-               adj_code[0] = 0x7d0a4378;       //mr r10,r8
-               adj_code[1] = 0x7ce93b78;       //mr r9,r7
-               adj_code[2] = 0x7cc83378;       //mr r8,r6
-               adj_code[3] = 0x7ca72b78;       //mr r7,r5
-               adj_code[4] = 0x7c862378;       //mr r6,r4
-               adj_code[5] = 0x7c651b78;       //mr r5,r3
-               
-               adj_code[6] = 0x3c000000;       //lis r0,hi(wptr)
-               adj_code[6] |= ((unsigned long)wptr) >> 16;
-               
-               adj_code[7] = 0x3c600000;       //lis r3,hi(hptr)
-               adj_code[7] |= ((unsigned long)hptr) >> 16;
-               
-               adj_code[8] = 0x60000000;       //ori r0,r0,lo(wptr)
-               adj_code[8] |= ((unsigned long)wptr) & 0xFFFF; 
-               
-               adj_code[9] = 0x60630000;       //ori r3,r3,lo(hptr)
-               adj_code[9] |= ((unsigned long)hptr) & 0xFFFF;
-               
-               adj_code[10] = 0x7c0903a6;      //mtctr r0
-               adj_code[11] = 0x4e800420;      //bctr
-               adj_code[12] = (unsigned long)hptr;
-               
-               // Flush the Instruction cache:
-               //      MakeDataExecutable(adjustor,4*13);
-                       /* This would require us to link with CoreServices.framework */
-               {               /* this should do the same: */
-                       int n = 13;
-                       unsigned long *p = adj_code;
-                       while(n--)
-                       {
-                               __asm__ volatile ("dcbf 0,%0\n\tsync\n\ticbi 0,%0"
-                                                   : : "r" (p));
-                               p++;
-                       }
-                       __asm__ volatile ("sync\n\tisync");
-               }
-       }
-#elif defined(ia64_TARGET_ARCH)
+#elif defined(powerpc_HOST_ARCH) && defined(linux_HOST_OS)
+
+#define OP_LO(op,lo)  ((((unsigned)(op)) << 16) | (((unsigned)(lo)) & 0xFFFF))
+#define OP_HI(op,hi)  ((((unsigned)(op)) << 16) | (((unsigned)(hi)) >> 16))
+    {
+        /* The PowerPC Linux (32-bit) calling convention is annoyingly complex.
+           We need to calculate all the details of the stack frame layout,
+           taking into account the types of all the arguments, and then
+           generate code on the fly. */
+    
+        int src_gpr = 3, dst_gpr = 5;
+        int fpr = 3;
+        int src_offset = 0, dst_offset = 0;
+        int n = strlen(typeString),i;
+        int src_locs[n], dst_locs[n];
+        int frameSize;
+        unsigned *code;
+      
+            /* Step 1:
+               Calculate where the arguments should go.
+               src_locs[] will contain the locations of the arguments in the
+               original stack frame passed to the adjustor.
+               dst_locs[] will contain the locations of the arguments after the
+               adjustor runs, on entry to the wrapper proc pointed to by wptr.
+
+               This algorithm is based on the one described on page 3-19 of the
+               System V ABI PowerPC Processor Supplement.
+            */
+        for(i=0;typeString[i];i++)
+        {
+            char t = typeString[i];
+            if((t == 'f' || t == 'd') && fpr <= 8)
+                src_locs[i] = dst_locs[i] = -32-(fpr++);
+            else
+            {
+                if(t == 'l' && src_gpr <= 9)
+                {
+                    if((src_gpr & 1) == 0)
+                        src_gpr++;
+                    src_locs[i] = -src_gpr;
+                    src_gpr += 2;
+                }
+                else if(t == 'i' && src_gpr <= 10)
+                {
+                    src_locs[i] = -(src_gpr++);
+                }
+                else
+                {
+                    if(t == 'l' || t == 'd')
+                    {
+                        if(src_offset % 8)
+                            src_offset += 4;
+                    }
+                    src_locs[i] = src_offset;
+                    src_offset += (t == 'l' || t == 'd') ? 8 : 4;
+                }
+
+                if(t == 'l' && dst_gpr <= 9)
+                {
+                    if((dst_gpr & 1) == 0)
+                        dst_gpr++;
+                    dst_locs[i] = -dst_gpr;
+                    dst_gpr += 2;
+                }
+                else if(t == 'i' && dst_gpr <= 10)
+                {
+                    dst_locs[i] = -(dst_gpr++);
+                }
+                else
+                {
+                    if(t == 'l' || t == 'd')
+                    {
+                        if(dst_offset % 8)
+                            dst_offset += 4;
+                    }
+                    dst_locs[i] = dst_offset;
+                    dst_offset += (t == 'l' || t == 'd') ? 8 : 4;
+                }
+            }
+        }
+
+        frameSize = dst_offset + 8;
+        frameSize = (frameSize+15) & ~0xF;
+
+            /* Step 2:
+               Build the adjustor.
+            */
+                    // allocate space for at most 4 insns per parameter
+                    // plus 14 more instructions.
+        adjustor = mallocBytesRWX(4 * (4*n + 14));
+        code = (unsigned*)adjustor;
+        
+        *code++ = 0x48000008; // b *+8
+            // * Put the hptr in a place where freeHaskellFunctionPtr
+            //   can get at it.
+        *code++ = (unsigned) hptr;
+
+            // * save the link register
+        *code++ = 0x7c0802a6; // mflr r0;
+        *code++ = 0x90010004; // stw r0, 4(r1);
+            // * and build a new stack frame
+        *code++ = OP_LO(0x9421, -frameSize); // stwu r1, -frameSize(r1)
+
+            // * now generate instructions to copy arguments
+            //   from the old stack frame into the new stack frame.
+        for(i=n-1;i>=0;i--)
+        {
+            if(src_locs[i] < -32)
+                ASSERT(dst_locs[i] == src_locs[i]);
+            else if(src_locs[i] < 0)
+            {
+                // source in GPR.
+                ASSERT(typeString[i] != 'f' && typeString[i] != 'd');
+                if(dst_locs[i] < 0)
+                {
+                    ASSERT(dst_locs[i] > -32);
+                        // dst is in GPR, too.
+
+                    if(typeString[i] == 'l')
+                    {
+                            // mr dst+1, src+1
+                        *code++ = 0x7c000378
+                                | ((-dst_locs[i]+1) << 16)
+                                | ((-src_locs[i]+1) << 11)
+                                | ((-src_locs[i]+1) << 21);
+                    }
+                    // mr dst, src
+                    *code++ = 0x7c000378
+                            | ((-dst_locs[i]) << 16)
+                            | ((-src_locs[i]) << 11)
+                            | ((-src_locs[i]) << 21);
+                }
+                else
+                {
+                    if(typeString[i] == 'l')
+                    {
+                            // stw src+1, dst_offset+4(r1)
+                        *code++ = 0x90010000
+                                | ((-src_locs[i]+1) << 21)
+                                | (dst_locs[i] + 4);
+                    }
+                    
+                        // stw src, dst_offset(r1)
+                    *code++ = 0x90010000
+                            | ((-src_locs[i]) << 21)
+                            | (dst_locs[i] + 8);
+                }
+            }
+            else
+            {
+                ASSERT(dst_locs[i] >= 0);
+                ASSERT(typeString[i] != 'f' && typeString[i] != 'd');
+
+                if(typeString[i] == 'l')
+                {
+                    // lwz r0, src_offset(r1)
+                        *code++ = 0x80010000
+                                | (src_locs[i] + frameSize + 8 + 4);
+                    // stw r0, dst_offset(r1)
+                        *code++ = 0x90010000
+                                | (dst_locs[i] + 8 + 4);
+                    }
+                // lwz r0, src_offset(r1)
+                    *code++ = 0x80010000
+                            | (src_locs[i] + frameSize + 8);
+                // stw r0, dst_offset(r1)
+                    *code++ = 0x90010000
+                            | (dst_locs[i] + 8);
+           }
+        }
+
+            // * hptr will be the new first argument.
+            // lis r3, hi(hptr)
+        *code++ = OP_HI(0x3c60, hptr);
+            // ori r3,r3,lo(hptr)
+        *code++ = OP_LO(0x6063, hptr);
+
+            // * we need to return to a piece of code
+            //   which will tear down the stack frame.
+            // lis r11,hi(obscure_ccall_ret_code)
+        *code++ = OP_HI(0x3d60, obscure_ccall_ret_code);
+            // ori r11,r11,lo(obscure_ccall_ret_code)
+        *code++ = OP_LO(0x616b, obscure_ccall_ret_code);
+            // mtlr r11
+        *code++ = 0x7d6803a6;
+
+            // * jump to wptr
+            // lis r11,hi(wptr)
+        *code++ = OP_HI(0x3d60, wptr);
+            // ori r11,r11,lo(wptr)
+        *code++ = OP_LO(0x616b, wptr);
+            // mtctr r11
+        *code++ = 0x7d6903a6;
+            // bctr
+        *code++ = 0x4e800420;
+
+        // Flush the Instruction cache:
+        {
+            unsigned *p = adjustor;
+            while(p < code)
+            {
+                __asm__ volatile ("dcbf 0,%0\n\tsync\n\ticbi 0,%0"
+                                 : : "r" (p));
+                p++;
+            }
+            __asm__ volatile ("sync\n\tisync");
+        }
+    }
+
+#elif defined(powerpc_HOST_ARCH) || defined(powerpc64_HOST_ARCH)
+        
+#define OP_LO(op,lo)  ((((unsigned)(op)) << 16) | (((unsigned)(lo)) & 0xFFFF))
+#define OP_HI(op,hi)  ((((unsigned)(op)) << 16) | (((unsigned)(hi)) >> 16))
+    {
+        /* The following code applies to all PowerPC and PowerPC64 platforms
+           whose stack layout is based on the AIX ABI.
+
+           Besides (obviously) AIX, this includes
+            Mac OS 9 and BeOS/PPC (may they rest in peace),
+                which use the 32-bit AIX ABI
+            powerpc64-linux,
+                which uses the 64-bit AIX ABI
+            and Darwin (Mac OS X),
+                which uses the same stack layout as AIX,
+                but no function descriptors.
+
+           The actual stack-frame shuffling is implemented out-of-line
+           in the function adjustorCode, in AdjustorAsm.S.
+           Here, we set up an AdjustorStub structure, which
+           is a function descriptor (on platforms that have function
+           descriptors) or a short piece of stub code (on Darwin) to call
+           adjustorCode with a pointer to the AdjustorStub struct loaded
+           into register r2.
+
+           One nice thing about this is that there is _no_ code generated at
+           runtime on the platforms that have function descriptors.
+        */
+        AdjustorStub *adjustorStub;
+        int sz = 0, extra_sz, total_sz;
+
+            // from AdjustorAsm.s
+            // not declared as a function so that AIX-style
+            // fundescs can never get in the way.
+        extern void *adjustorCode;
+        
+#ifdef FUNDESCS
+        adjustorStub = stgMallocBytes(sizeof(AdjustorStub), "createAdjustor");
+#else
+        adjustorStub = mallocBytesRWX(sizeof(AdjustorStub));
+#endif
+        adjustor = adjustorStub;
+            
+        adjustorStub->code = (void*) &adjustorCode;
+
+#ifdef FUNDESCS
+            // function descriptors are a cool idea.
+            // We don't need to generate any code at runtime.
+        adjustorStub->toc = adjustorStub;
+#else
+
+            // no function descriptors :-(
+            // We need to do things "by hand".
+#if defined(powerpc_HOST_ARCH)
+            // lis  r2, hi(adjustorStub)
+        adjustorStub->lis = OP_HI(0x3c40, adjustorStub);
+            // ori  r2, r2, lo(adjustorStub)
+        adjustorStub->ori = OP_LO(0x6042, adjustorStub);
+            // lwz r0, code(r2)
+        adjustorStub->lwz = OP_LO(0x8002, (char*)(&adjustorStub->code)
+                                        - (char*)adjustorStub);
+            // mtctr r0
+        adjustorStub->mtctr = 0x7c0903a6;
+            // bctr
+        adjustorStub->bctr = 0x4e800420;
+#else
+        barf("adjustor creation not supported on this platform");
+#endif
+
+        // Flush the Instruction cache:
+        {
+            int n = sizeof(AdjustorStub)/sizeof(unsigned);
+            unsigned *p = (unsigned*)adjustor;
+            while(n--)
+            {
+                __asm__ volatile ("dcbf 0,%0\n\tsync\n\ticbi 0,%0"
+                                    : : "r" (p));
+                p++;
+            }
+            __asm__ volatile ("sync\n\tisync");
+        }
+#endif
+
+            // Calculate the size of the stack frame, in words.
+        while(*typeString)
+        {
+            char t = *typeString++;
+
+            switch(t)
+            {
+#if defined(powerpc_HOST_ARCH)
+                    // on 32-bit platforms, Double and Int64 occupy two words.
+                case 'd':
+                case 'l':
+                    sz += 2;
+                    break;
+#endif
+                    // everything else is one word.
+                default:
+                    sz += 1;
+            }
+        }
+            // The first eight words of the parameter area
+            // are just "backing store" for the parameters passed in
+            // the GPRs. extra_sz is the number of words beyond those first
+            // 8 words.
+        extra_sz = sz - 8;
+        if(extra_sz < 0)
+            extra_sz = 0;
+
+            // Calculate the total size of the stack frame.
+        total_sz = (6 /* linkage area */
+                  + 8 /* minimum parameter area */
+                  + 2 /* two extra arguments */
+                  + extra_sz)*sizeof(StgWord);
+       
+            // align to 16 bytes.
+            // AIX only requires 8 bytes, but who cares?
+        total_sz = (total_sz+15) & ~0xF;
+       
+            // Fill in the information that adjustorCode in AdjustorAsm.S
+            // will use to create a new stack frame with the additional args.
+        adjustorStub->hptr = hptr;
+        adjustorStub->wptr = wptr;
+        adjustorStub->negative_framesize = -total_sz;
+        adjustorStub->extrawords_plus_one = extra_sz + 1;
+    }
+
+#elif defined(ia64_HOST_ARCH)
 /*
     Up to 8 inputs are passed in registers.  We flush the last two inputs to
     the stack, initially into the 16-byte scratch region left by the caller.
@@ -498,7 +836,7 @@ TODO: Depending on how much allocation overhead stgMallocBytes uses for
 void
 freeHaskellFunctionPtr(void* ptr)
 {
-#if defined(i386_TARGET_ARCH)
+#if defined(i386_HOST_ARCH)
  if ( *(unsigned char*)ptr != 0x68 &&
       *(unsigned char*)ptr != 0x58 ) {
    errorBelch("freeHaskellFunctionPtr: not for me, guv! %p\n", ptr);
@@ -511,7 +849,7 @@ freeHaskellFunctionPtr(void* ptr)
  } else {
     freeStablePtr(*((StgStablePtr*)((unsigned char*)ptr + 0x02)));
  }    
-#elif defined(sparc_TARGET_ARCH)
+#elif defined(sparc_HOST_ARCH)
  if ( *(unsigned long*)ptr != 0x9C23A008UL ) {
    errorBelch("freeHaskellFunctionPtr: not for me, guv! %p\n", ptr);
    return;
@@ -519,7 +857,7 @@ freeHaskellFunctionPtr(void* ptr)
 
  /* Free the stable pointer first..*/
  freeStablePtr(*((StgStablePtr*)((unsigned long*)ptr + 11)));
-#elif defined(alpha_TARGET_ARCH)
+#elif defined(alpha_HOST_ARCH)
  if ( *(StgWord64*)ptr != 0xa77b0018a61b0010L ) {
    errorBelch("freeHaskellFunctionPtr: not for me, guv! %p\n", ptr);
    return;
@@ -527,13 +865,20 @@ freeHaskellFunctionPtr(void* ptr)
 
  /* Free the stable pointer first..*/
  freeStablePtr(*((StgStablePtr*)((unsigned char*)ptr + 0x10)));
-#elif defined(powerpc_TARGET_ARCH)
- if ( *(StgWord*)ptr != 0x7d0a4378 ) {
+#elif defined(powerpc_HOST_ARCH) && defined(linux_HOST_OS)
+ if ( *(StgWord*)ptr != 0x48000008 ) {
+   errorBelch("freeHaskellFunctionPtr: not for me, guv! %p\n", ptr);
+   return;
+ }
+ freeStablePtr(((StgStablePtr*)ptr)[1]);
+#elif defined(powerpc_HOST_ARCH) || defined(powerpc64_HOST_ARCH)
+ extern void* adjustorCode;
+ if ( ((AdjustorStub*)ptr)->code != (StgFunPtr) &adjustorCode ) {
    errorBelch("freeHaskellFunctionPtr: not for me, guv! %p\n", ptr);
    return;
  }
- freeStablePtr(*((StgStablePtr*)((unsigned char*)ptr + 4*12)));
-#elif defined(ia64_TARGET_ARCH)
+ freeStablePtr(((AdjustorStub*)ptr)->hptr);
+#elif defined(ia64_HOST_ARCH)
  IA64FunDesc *fdesc = (IA64FunDesc *)ptr;
  StgWord64 *code = (StgWord64 *)(fdesc+1);
 
@@ -561,7 +906,7 @@ freeHaskellFunctionPtr(void* ptr)
 void
 initAdjustor(void)
 {
-#if defined(i386_TARGET_ARCH)
+#if defined(i386_HOST_ARCH)
   /* Now here's something obscure for you:
 
   When generating an adjustor thunk that uses the C calling
@@ -579,14 +924,12 @@ initAdjustor(void)
   to return to it before tail jumping from the adjustor thunk.
   */
 
-  obscure_ccall_ret_code = stgMallocBytes(4, "initAdjustor");
+  obscure_ccall_ret_code = mallocBytesRWX(4);
 
   obscure_ccall_ret_code[0x00] = (unsigned char)0x83;  /* addl $0x4, %esp */
   obscure_ccall_ret_code[0x01] = (unsigned char)0xc4;
   obscure_ccall_ret_code[0x02] = (unsigned char)0x04;
 
   obscure_ccall_ret_code[0x03] = (unsigned char)0xc3;  /* ret */
-
-  execPage(obscure_ccall_ret_code, pageExecuteRead);
 #endif
 }