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"
#include "RtsUtils.h"
-#include "RtsFlags.h"
+#include <stdlib.h>
+
+#if defined(_WIN32)
+#include <windows.h>
+#endif
+
+#if defined(openbsd_HOST_OS)
+#include <unistd.h>
+#include <sys/types.h>
+#include <sys/mman.h>
+
+/* 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.. */
-#if defined(i386_TARGET_ARCH) || defined(sparc_TARGET_ARCH)
-
-/* Now here's something obscure for you:
-
- When generating an adjustor thunk that uses the C calling
- convention, we have to make sure that the thunk kicks off
- the process of jumping into Haskell with a tail jump. Why?
- Because as a result of jumping in into Haskell we may end
- up freeing the very adjustor thunk we came from using
- freeHaskellFunctionPtr(). Hence, we better not return to
- the adjustor code on our way out, since it could by then
- point to junk.
-
- The fix is readily at hand, just include the opcodes
- for the C stack fixup code that we need to perform when
- returning in some static piece of memory and arrange
- to return to it before tail jumping from the adjustor thunk.
-
- For this to work we make the assumption that bytes in .data
- are considered executable.
-*/
-static unsigned char __obscure_ccall_ret_code [] =
- { 0x83, 0xc4, 0x04 /* addl $0x4, %esp */
- , 0xc3 /* ret */
- };
+/*
+ * Allocate len bytes which are readable, writable, and 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*
+mallocBytesRWX(int len)
+{
+ 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;
+}
-void*
-createAdjustor(int cconv, StgStablePtr hptr, StgFunPtr wptr)
+#if defined(i386_HOST_ARCH)
+static unsigned char *obscure_ccall_ret_code;
+#endif
+
+#if defined(alpha_HOST_ARCH)
+/* To get the definition of PAL_imb: */
+# if defined(linux_HOST_OS)
+# include <asm/pal.h>
+# else
+# include <machine/pal.h>
+# endif
+#endif
+
+#if defined(ia64_HOST_ARCH)
+#include "Storage.h"
+
+/* Layout of a function descriptor */
+typedef struct _IA64FunDesc {
+ StgWord64 ip;
+ StgWord64 gp;
+} IA64FunDesc;
+
+static void *
+stgAllocStable(size_t size_in_bytes, StgStablePtr *stable)
{
- void *adjustor;
- unsigned char* adj_code;
- size_t sizeof_adjustor;
+ StgArrWords* arr;
+ nat data_size_in_words, total_size_in_words;
- if (cconv == 0) { /* the adjustor will be _stdcall'ed */
+ /* round up to a whole number of words */
+ data_size_in_words = (size_in_bytes + sizeof(W_) + 1) / sizeof(W_);
+ total_size_in_words = sizeofW(StgArrWords) + data_size_in_words;
+
+ /* allocate and fill it in */
+ arr = (StgArrWords *)allocate(total_size_in_words);
+ SET_ARR_HDR(arr, &stg_ARR_WORDS_info, CCCS, data_size_in_words);
+
+ /* obtain a stable ptr */
+ *stable = getStablePtr((StgPtr)arr);
+
+ /* and return a ptr to the goods inside the array */
+ return(BYTE_ARR_CTS(arr));
+}
+#endif
-#if defined(sparc_TARGET_ARCH)
- /* SPARC doesn't have a calling convention other than _ccall */
- if (cconv == 0) {
- return NULL;
- }
+#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,
+ 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_HOST_ARCH)
/* Magic constant computed by inspecting the code length of
the following assembly language snippet
(offset and machine code prefixed):
<c>: ff e0 jmp %eax # and jump to it.
# the callee cleans up the stack
*/
- sizeof_adjustor = 14*sizeof(char);
-
- if ((adjustor = stgMallocBytes(sizeof_adjustor,"createAdjustor")) == NULL) {
- return NULL;
- }
-
- adj_code = (unsigned char*)adjustor;
- adj_code[0x00] = (unsigned char)0x58; /* popl %eax */
-
- adj_code[0x01] = (unsigned char)0x68; /* pushl hptr (which is a dword immediate ) */
- *((StgStablePtr*)(adj_code + 0x02)) = (StgStablePtr)hptr;
-
- adj_code[0x06] = (unsigned char)0x50; /* pushl %eax */
+ adjustor = mallocBytesRWX(14);
+ {
+ unsigned char *const adj_code = (unsigned char *)adjustor;
+ adj_code[0x00] = (unsigned char)0x58; /* popl %eax */
- adj_code[0x07] = (unsigned char)0xb8; /* movl $wptr, %eax */
- *((StgFunPtr*)(adj_code + 0x08)) = (StgFunPtr)wptr;
+ adj_code[0x01] = (unsigned char)0x68; /* pushl hptr (which is a dword immediate ) */
+ *((StgStablePtr*)(adj_code + 0x02)) = (StgStablePtr)hptr;
- adj_code[0x0c] = (unsigned char)0xff; /* jmp %eax */
- adj_code[0x0d] = (unsigned char)0xe0;
+ adj_code[0x06] = (unsigned char)0x50; /* pushl %eax */
+ adj_code[0x07] = (unsigned char)0xb8; /* movl $wptr, %eax */
+ *((StgFunPtr*)(adj_code + 0x08)) = (StgFunPtr)wptr;
- } else { /* the adjustor will be _ccall'ed */
+ adj_code[0x0c] = (unsigned char)0xff; /* jmp %eax */
+ adj_code[0x0d] = (unsigned char)0xe0;
+ }
+#endif
+ break;
-#if defined(i386_TARGET_ARCH)
+ case 1: /* _ccall */
+#if defined(i386_HOST_ARCH)
/* Magic constant computed by inspecting the code length of
the following assembly language snippet
(offset and machine code prefixed):
<00>: 68 ef be ad de pushl $0xdeadbeef # constant is large enough to
# hold a StgStablePtr
<05>: b8 fa ef ff 00 movl $0x00ffeffa, %eax # load up wptr
- <0a>: 68 ef be ad de pushl $__obscure_ccall_ret_code # push the return address
+ <0a>: 68 ef be ad de pushl $obscure_ccall_ret_code # push the return address
<0f>: ff e0 jmp *%eax # jump to wptr
The ccall'ing version is a tad different, passing in the return
via the stable pointer.) (The auto-generated C stub is in on this
game, don't worry :-)
- See the comment next to __obscure_ccall_ret_code why we need to
+ See the comment next to obscure_ccall_ret_code why we need to
perform a tail jump instead of a call, followed by some C stack
fixup.
coming back from the C stub is not stored on the stack.
That's (thankfully) the case here with the restricted set of
return types that we support.
-
-
*/
- sizeof_adjustor = 17*sizeof(char);
+ adjustor = mallocBytesRWX(17);
+ {
+ unsigned char *const adj_code = (unsigned char *)adjustor;
- if ((adjustor = stgMallocBytes(sizeof_adjustor,"createAdjustor")) == NULL) {
- return NULL;
- }
+ adj_code[0x00] = (unsigned char)0x68; /* pushl hptr (which is a dword immediate ) */
+ *((StgStablePtr*)(adj_code+0x01)) = (StgStablePtr)hptr;
- adj_code = (unsigned char*)adjustor;
+ adj_code[0x05] = (unsigned char)0xb8; /* movl $wptr, %eax */
+ *((StgFunPtr*)(adj_code + 0x06)) = (StgFunPtr)wptr;
- adj_code[0x00] = (unsigned char)0x68; /* pushl hptr (which is a dword immediate ) */
- *((StgStablePtr*)(adj_code+0x01)) = (StgStablePtr)hptr;
+ adj_code[0x0a] = (unsigned char)0x68; /* pushl obscure_ccall_ret_code */
+ *((StgFunPtr*)(adj_code + 0x0b)) = (StgFunPtr)obscure_ccall_ret_code;
- adj_code[0x05] = (unsigned char)0xb8; /* movl $wptr, %eax */
- *((StgFunPtr*)(adj_code + 0x06)) = (StgFunPtr)wptr;
-
- adj_code[0x0a] = (unsigned char)0x68; /* pushl __obscure_ccall_ret_code */
- *((StgFunPtr*)(adj_code + 0x0b)) = (StgFunPtr)__obscure_ccall_ret_code;
-
- adj_code[0x0f] = (unsigned char)0xff; /* jmp *%eax */
- adj_code[0x10] = (unsigned char)0xe0;
-
-#elif defined(sparc_TARGET_ARCH)
+ adj_code[0x0f] = (unsigned char)0xff; /* jmp *%eax */
+ adj_code[0x10] = (unsigned char)0xe0;
+ }
+#elif defined(sparc_HOST_ARCH)
+ /* Magic constant computed by inspecting the code length of the following
+ assembly language snippet (offset and machine code prefixed):
+
+ <00>: 9C23A008 sub %sp, 8, %sp ! make room for %o4/%o5 in caller's frame
+ <04>: DA23A060 st %o5, [%sp + 96] ! shift registers by 2 positions
+ <08>: D823A05C st %o4, [%sp + 92]
+ <0C>: 9A10000B mov %o3, %o5
+ <10>: 9810000A mov %o2, %o4
+ <14>: 96100009 mov %o1, %o3
+ <18>: 94100008 mov %o0, %o2
+ <1C>: 13000000 sethi %hi(wptr), %o1 ! load up wptr (1 of 2)
+ <20>: 11000000 sethi %hi(hptr), %o0 ! load up hptr (1 of 2)
+ <24>: 81C26000 jmp %o1 + %lo(wptr) ! jump to wptr (load 2 of 2)
+ <28>: 90122000 or %o0, %lo(hptr), %o0 ! load up hptr (2 of 2, delay slot)
+ <2C> 00000000 ! place for getting hptr back easily
+
+ ccall'ing on SPARC is easy, because we are quite lucky to push a
+ multiple of 8 bytes (1 word hptr + 1 word dummy arg) in front of the
+ existing arguments (note that %sp must stay double-word aligned at
+ all times, see ABI spec at http://www.sparc.org/standards/psABI3rd.pdf).
+ To do this, we extend the *caller's* stack frame by 2 words and shift
+ the output registers used for argument passing (%o0 - %o5, we are a *leaf*
+ procedure because of the tail-jump) by 2 positions. This makes room in
+ %o0 and %o1 for the additinal arguments, namely hptr and a dummy (used
+ for destination addr of jump on SPARC, return address on x86, ...). This
+ shouldn't cause any problems for a C-like caller: alloca is implemented
+ similarly, and local variables should be accessed via %fp, not %sp. In a
+ nutshell: This should work! (Famous last words! :-)
+ */
+ adjustor = mallocBytesRWX(4*(11+1));
+ {
+ unsigned long *const adj_code = (unsigned long *)adjustor;
+
+ adj_code[ 0] = 0x9C23A008UL; /* sub %sp, 8, %sp */
+ adj_code[ 1] = 0xDA23A060UL; /* st %o5, [%sp + 96] */
+ adj_code[ 2] = 0xD823A05CUL; /* st %o4, [%sp + 92] */
+ adj_code[ 3] = 0x9A10000BUL; /* mov %o3, %o5 */
+ adj_code[ 4] = 0x9810000AUL; /* mov %o2, %o4 */
+ adj_code[ 5] = 0x96100009UL; /* mov %o1, %o3 */
+ adj_code[ 6] = 0x94100008UL; /* mov %o0, %o2 */
+ adj_code[ 7] = 0x13000000UL; /* sethi %hi(wptr), %o1 */
+ adj_code[ 7] |= ((unsigned long)wptr) >> 10;
+ adj_code[ 8] = 0x11000000UL; /* sethi %hi(hptr), %o0 */
+ adj_code[ 8] |= ((unsigned long)hptr) >> 10;
+ adj_code[ 9] = 0x81C26000UL; /* jmp %o1 + %lo(wptr) */
+ adj_code[ 9] |= ((unsigned long)wptr) & 0x000003FFUL;
+ adj_code[10] = 0x90122000UL; /* or %o0, %lo(hptr), %o0 */
+ adj_code[10] |= ((unsigned long)hptr) & 0x000003FFUL;
+
+ adj_code[11] = (unsigned long)hptr;
+
+ /* flush cache */
+ asm("flush %0" : : "r" (adj_code ));
+ asm("flush %0" : : "r" (adj_code + 2));
+ asm("flush %0" : : "r" (adj_code + 4));
+ asm("flush %0" : : "r" (adj_code + 6));
+ asm("flush %0" : : "r" (adj_code + 10));
+
+ /* max. 5 instructions latency, and we need at >= 1 for returning */
+ asm("nop");
+ asm("nop");
+ asm("nop");
+ asm("nop");
+ }
+#elif defined(alpha_HOST_ARCH)
/* Magic constant computed by inspecting the code length of
the following assembly language snippet
- (offset and machine code prefixed):
-
- <00>: 13 00 3f fb sethi %hi(0x00ffeffa), %o1 # load up wptr (1 of 2)
- <04>: 11 37 ab 6f sethi %hi(0xdeadbeef), %o0 # load up hptr (1 of 2)
- <08>: 81 c2 63 fa jmp %o1+%lo(0x00ffeffa) # jump to wptr (load 2 of 2)
- <0c>: 90 12 22 ef or %o0, %lo(0xdeadbeef), %o0 # load up hptr (2 of 2)
- # [in delay slot]
- <10>: de ad be ef # Place the value of the StgStablePtr somewhere readable
-
- ccall'ing on a SPARC leaves little to be performed by the caller.
- The callee shifts the window on entry and restores it on exit.
- Input paramters and results are passed via registers. (%o0 in the
- code above contains the input paramter to wptr.) The return address
- is stored in %o7/%i7. Since we don't shift the window in this code,
- the return address is preserved and wptr will return to our caller.
-
+ (offset and machine code prefixed; note that the machine code
+ shown is longwords stored in little-endian order):
+
+ <00>: 46520414 mov a2, a4
+ <04>: 46100412 mov a0, a2
+ <08>: a61b0020 ldq a0, 0x20(pv) # load up hptr
+ <0c>: 46730415 mov a3, a5
+ <10>: a77b0028 ldq pv, 0x28(pv) # load up wptr
+ <14>: 46310413 mov a1, a3
+ <18>: 6bfb---- jmp (pv), <hint> # jump to wptr (with hint)
+ <1c>: 00000000 # padding for alignment
+ <20>: [8 bytes for hptr quadword]
+ <28>: [8 bytes for wptr quadword]
+
+ The "computed" jump at <08> above is really a jump to a fixed
+ location. Accordingly, we place an always-correct hint in the
+ jump instruction, namely the address offset from <0c> to 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_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.
+
+ On the Alpha the calling convention is so complex and dependent
+ on the callee's signature -- for example, the stack pointer has
+ to be a multiple of 16 -- that it seems impossible to me [ccshan]
+ to handle the general case correctly without changing how the
+ adjustor is called from C. For now, our solution of shuffling
+ registers only and ignoring the stack only works if the original
+ caller passed 4 or fewer argument words.
+
+TODO: Depending on how much allocation overhead stgMallocBytes uses for
+ header information (more precisely, if the overhead is no more than
+ 4 bytes), we should move the first three instructions above down by
+ 4 bytes (getting rid of the nop), hence saving memory. [ccshan]
*/
- sizeof_adjustor = 28*sizeof(char);
-
- if ((adjustor = stgMallocBytes(sizeof_adjustor,"createAdjustor")) == NULL) {
- return NULL;
+ ASSERT(((StgWord64)wptr & 3) == 0);
+ adjustor = mallocBytesRWX(48);
+ {
+ StgWord64 *const code = (StgWord64 *)adjustor;
+
+ code[0] = 0x4610041246520414L;
+ code[1] = 0x46730415a61b0020L;
+ code[2] = 0x46310413a77b0028L;
+ code[3] = 0x000000006bfb0000L
+ | (((StgWord32*)(wptr) - (StgWord32*)(code) - 3) & 0x3fff);
+
+ code[4] = (StgWord64)hptr;
+ code[5] = (StgWord64)wptr;
+
+ /* Ensure that instruction cache is consistent with our new code */
+ __asm__ volatile("call_pal %0" : : "i" (PAL_imb));
+ }
+#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");
+ }
}
- adj_code = (unsigned char*)adjustor;
+#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
- /* sethi %hi(wptr), %o1 */
- *((unsigned long*)(adj_code+0x00)) = (unsigned long)0x13000000;
- *((unsigned long*)(adj_code+0x00)) |= ((unsigned long)wptr) >> 10;
+ // 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
- /* sethi %hi(hptr), %o0 */
- *((unsigned long*)(adj_code+0x04)) = (unsigned long)0x11000000;
- *((unsigned long*)(adj_code+0x04)) |= ((unsigned long)hptr) >> 10;
-
- /* jmp %o1+%lo(wptr) */
- *((unsigned long*)(adj_code+0x08)) = (unsigned long)0x81c26000;
- *((unsigned long*)(adj_code+0x08)) |= ((unsigned long)wptr) & 0x000003ff;
-
- /* or %o0, %lo(hptr), %o0 */
- *((unsigned long*)(adj_code+0x0c)) = (unsigned long)0x90122000;
- *((unsigned long*)(adj_code+0x0c)) |= ((unsigned long)hptr) & 0x000003ff;
+ // 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.
+ We then shuffle the others along by 4 (taking 2 registers for ourselves
+ to save return address and previous function state - we need to come back
+ here on the way out to restore the stack, so this is a real function
+ rather than just a trampoline).
- *((StgStablePtr*)(adj_code+0x10)) = (StgStablePtr)hptr;
+ The function descriptor we create contains the gp of the target function
+ so gp is already loaded correctly.
+
+ [MLX] alloc r16=ar.pfs,10,2,0
+ movl r17=wptr
+ [MII] st8.spill [r12]=r38,8 // spill in6 (out4)
+ mov r41=r37 // out7 = in5 (out3)
+ mov r40=r36;; // out6 = in4 (out2)
+ [MII] st8.spill [r12]=r39 // spill in7 (out5)
+ mov.sptk b6=r17,50
+ mov r38=r34;; // out4 = in2 (out0)
+ [MII] mov r39=r35 // out5 = in3 (out1)
+ mov r37=r33 // out3 = in1 (loc1)
+ mov r36=r32 // out2 = in0 (loc0)
+ [MLX] adds r12=-24,r12 // update sp
+ movl r34=hptr;; // out0 = hptr
+ [MIB] mov r33=r16 // loc1 = ar.pfs
+ mov r32=b0 // loc0 = retaddr
+ br.call.sptk.many b0=b6;;
+
+ [MII] adds r12=-16,r12
+ mov b0=r32
+ mov.i ar.pfs=r33
+ [MFB] nop.m 0x0
+ nop.f 0x0
+ br.ret.sptk.many b0;;
+*/
+
+/* These macros distribute a long constant into the two words of an MLX bundle */
+#define BITS(val,start,count) (((val) >> (start)) & ((1 << (count))-1))
+#define MOVL_LOWORD(val) (BITS(val,22,18) << 46)
+#define MOVL_HIWORD(val) (BITS(val,40,23) | (BITS(val,0,7) << 36) | (BITS(val,7,9) << 50) \
+ | (BITS(val,16,5) << 55) | (BITS(val,21,1) << 44) | BITS(val,63,1) << 59)
+
+ {
+ StgStablePtr stable;
+ IA64FunDesc *wdesc = (IA64FunDesc *)wptr;
+ StgWord64 wcode = wdesc->ip;
+ IA64FunDesc *fdesc;
+ StgWord64 *code;
+
+ /* we allocate on the Haskell heap since malloc'd memory isn't executable - argh */
+ adjustor = stgAllocStable(sizeof(IA64FunDesc)+18*8, &stable);
+
+ fdesc = (IA64FunDesc *)adjustor;
+ code = (StgWord64 *)(fdesc + 1);
+ fdesc->ip = (StgWord64)code;
+ fdesc->gp = wdesc->gp;
+
+ code[0] = 0x0000058004288004 | MOVL_LOWORD(wcode);
+ code[1] = 0x6000000220000000 | MOVL_HIWORD(wcode);
+ code[2] = 0x029015d818984001;
+ code[3] = 0x8401200500420094;
+ code[4] = 0x886011d8189c0001;
+ code[5] = 0x84011004c00380c0;
+ code[6] = 0x0250210046013800;
+ code[7] = 0x8401000480420084;
+ code[8] = 0x0000233f19a06005 | MOVL_LOWORD((StgWord64)hptr);
+ code[9] = 0x6000000440000000 | MOVL_HIWORD((StgWord64)hptr);
+ code[10] = 0x0200210020010811;
+ code[11] = 0x1080006800006200;
+ code[12] = 0x0000210018406000;
+ code[13] = 0x00aa021000038005;
+ code[14] = 0x000000010000001d;
+ code[15] = 0x0084000880000200;
+
+ /* save stable pointers in convenient form */
+ code[16] = (StgWord64)hptr;
+ code[17] = (StgWord64)stable;
+ }
+#else
+ barf("adjustor creation not supported on this platform");
#endif
+ break;
+ default:
+ ASSERT(0);
+ break;
}
/* Have fun! */
- return ((void*)adjustor);
+ return adjustor;
}
+
void
freeHaskellFunctionPtr(void* ptr)
{
-#if defined(i386_TARGET_ARCH)
+#if defined(i386_HOST_ARCH)
if ( *(unsigned char*)ptr != 0x68 &&
*(unsigned char*)ptr != 0x58 ) {
- fprintf(stderr, "freeHaskellFunctionPtr: not for me, guv! %p\n", ptr);
+ errorBelch("freeHaskellFunctionPtr: not for me, guv! %p\n", ptr);
return;
}
} else {
freeStablePtr(*((StgStablePtr*)((unsigned char*)ptr + 0x02)));
}
-#elif defined(sparc_TARGET_ARCH)
- if ( *(unsigned char*)ptr != 0x13 ) {
- fprintf(stderr, "freeHaskellFunctionPtr: not for me, guv! %p\n", ptr);
+#elif defined(sparc_HOST_ARCH)
+ if ( *(unsigned long*)ptr != 0x9C23A008UL ) {
+ errorBelch("freeHaskellFunctionPtr: not for me, guv! %p\n", ptr);
+ return;
+ }
+
+ /* Free the stable pointer first..*/
+ freeStablePtr(*((StgStablePtr*)((unsigned long*)ptr + 11)));
+#elif defined(alpha_HOST_ARCH)
+ if ( *(StgWord64*)ptr != 0xa77b0018a61b0010L ) {
+ errorBelch("freeHaskellFunctionPtr: not for me, guv! %p\n", ptr);
return;
}
/* Free the stable pointer first..*/
freeStablePtr(*((StgStablePtr*)((unsigned char*)ptr + 0x10)));
+#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(((AdjustorStub*)ptr)->hptr);
+#elif defined(ia64_HOST_ARCH)
+ IA64FunDesc *fdesc = (IA64FunDesc *)ptr;
+ StgWord64 *code = (StgWord64 *)(fdesc+1);
+
+ if (fdesc->ip != (StgWord64)code) {
+ errorBelch("freeHaskellFunctionPtr: not for me, guv! %p\n", ptr);
+ return;
+ }
+ freeStablePtr((StgStablePtr)code[16]);
+ freeStablePtr((StgStablePtr)code[17]);
+ return;
+#else
+ ASSERT(0);
#endif
*((unsigned char*)ptr) = '\0';
- free(ptr);
+ stgFree(ptr);
}
-#endif /* i386_TARGET_ARCH || sparc_TARGET_ARCH */
+/*
+ * Function: initAdjustor()
+ *
+ * Perform initialisation of adjustor thunk layer (if needed.)
+ */
+void
+initAdjustor(void)
+{
+#if defined(i386_HOST_ARCH)
+ /* Now here's something obscure for you:
+
+ When generating an adjustor thunk that uses the C calling
+ convention, we have to make sure that the thunk kicks off
+ the process of jumping into Haskell with a tail jump. Why?
+ Because as a result of jumping in into Haskell we may end
+ up freeing the very adjustor thunk we came from using
+ freeHaskellFunctionPtr(). Hence, we better not return to
+ the adjustor code on our way out, since it could by then
+ point to junk.
+
+ The fix is readily at hand, just include the opcodes
+ for the C stack fixup code that we need to perform when
+ returning in some static piece of memory and arrange
+ to return to it before tail jumping from the adjustor thunk.
+ */
+
+ 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 */
+#endif
+}