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Diffstat (limited to 'rts/Adjustor.c')
| -rw-r--r-- | rts/Adjustor.c | 1110 |
1 files changed, 1110 insertions, 0 deletions
diff --git a/rts/Adjustor.c b/rts/Adjustor.c new file mode 100644 index 0000000000..f3e5bfe6aa --- /dev/null +++ b/rts/Adjustor.c @@ -0,0 +1,1110 @@ +/* ----------------------------------------------------------------------------- + * Foreign export adjustor thunks + * + * Copyright (c) 1998. + * + * ---------------------------------------------------------------------------*/ + +/* A little bit of background... + +An adjustor thunk is a dynamically allocated code snippet that allows +Haskell closures to be viewed as C function pointers. + +Stable pointers provide a way for the outside world to get access to, +and evaluate, Haskell heap objects, with the RTS providing a small +range of ops for doing so. So, assuming we've got a stable pointer in +our hand in C, we can jump into the Haskell world and evaluate a callback +procedure, say. This works OK in some cases where callbacks are used, but +does require the external code to know about stable pointers and how to deal +with them. We'd like to hide the Haskell-nature of a callback and have it +be invoked just like any other C function pointer. + +Enter adjustor thunks. An adjustor thunk is a little piece of code +that's generated on-the-fly (one per Haskell closure being exported) +that, when entered using some 'universal' calling convention (e.g., the +C calling convention on platform X), pushes an implicit stable pointer +(to the Haskell callback) before calling another (static) C function stub +which takes care of entering the Haskell code via its stable pointer. + +An adjustor thunk is allocated on the C heap, and is called from within +Haskell just before handing out the function pointer to the Haskell (IO) +action. User code should never have to invoke it explicitly. + +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" +#include "RtsUtils.h" +#include <stdlib.h> + +#if defined(_WIN32) +#include <windows.h> +#endif + +#if defined(powerpc_HOST_ARCH) && defined(linux_HOST_OS) +#include <string.h> +#endif + +#ifdef LEADING_UNDERSCORE +#define UNDERSCORE "_" +#else +#define UNDERSCORE "" +#endif +#if defined(i386_HOST_ARCH) && !defined(darwin_HOST_OS) +/* + 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. +*/ +static void GNUC3_ATTRIBUTE(used) obscure_ccall_wrapper(void) +{ + __asm__ ( + ".globl " UNDERSCORE "obscure_ccall_ret_code\n" + UNDERSCORE "obscure_ccall_ret_code:\n\t" + "addl $0x4, %esp\n\t" + "ret" + ); +} +extern void obscure_ccall_ret_code(void); + +#if defined(openbsd_HOST_OS) +static unsigned char *obscure_ccall_ret_code_dyn; +#endif + +#endif + +#if defined(x86_64_HOST_ARCH) +static void GNUC3_ATTRIBUTE(used) obscure_ccall_wrapper(void) +{ + __asm__ ( + ".globl " UNDERSCORE "obscure_ccall_ret_code\n" + UNDERSCORE "obscure_ccall_ret_code:\n\t" + "addq $0x8, %rsp\n\t" + "ret" + ); +} +extern void obscure_ccall_ret_code(void); +#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) +{ + StgArrWords* arr; + nat data_size_in_words, total_size_in_words; + + /* 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(&(arr->payload)); +} +#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 + +#if defined(i386_HOST_ARCH) && defined(darwin_HOST_OS) + +/* !!! !!! WARNING: !!! !!! + * This structure is accessed from AdjustorAsm.s + * Any changes here have to be mirrored in the offsets there. + */ + +typedef struct AdjustorStub { + unsigned char call[8]; + StgStablePtr hptr; + StgFunPtr wptr; + StgInt frame_size; + StgInt argument_size; +} AdjustorStub; +#endif + +#if defined(darwin_HOST_OS) || defined(powerpc_HOST_ARCH) || defined(powerpc64_HOST_ARCH) +static int totalArgumentSize(char *typeString) +{ + int sz = 0; + while(*typeString) + { + char t = *typeString++; + + switch(t) + { + // on 32-bit platforms, Double and Int64 occupy two words. + case 'd': + case 'l': + if(sizeof(void*) == 4) + { + sz += 2; + break; + } + // everything else is one word. + default: + sz += 1; + } + } + return sz; +} +#endif + +void* +createAdjustor(int cconv, StgStablePtr hptr, + StgFunPtr wptr, + char *typeString +#if !defined(powerpc_HOST_ARCH) && !defined(powerpc64_HOST_ARCH) && !defined(x86_64_HOST_ARCH) + STG_UNUSED +#endif + ) +{ + void *adjustor = NULL; + + switch (cconv) + { + case 0: /* _stdcall */ +#if defined(i386_HOST_ARCH) && !defined(darwin_HOST_OS) + /* Magic constant computed by inspecting the code length of + the following assembly language snippet + (offset and machine code prefixed): + + <0>: 58 popl %eax # temp. remove ret addr.. + <1>: 68 fd fc fe fa pushl 0xfafefcfd # constant is large enough to + # hold a StgStablePtr + <6>: 50 pushl %eax # put back ret. addr + <7>: b8 fa ef ff 00 movl $0x00ffeffa, %eax # load up wptr + <c>: ff e0 jmp %eax # and jump to it. + # the callee cleans up the stack + */ + adjustor = stgMallocBytesRWX(14); + { + unsigned char *const 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 */ + + adj_code[0x07] = (unsigned char)0xb8; /* movl $wptr, %eax */ + *((StgFunPtr*)(adj_code + 0x08)) = (StgFunPtr)wptr; + + adj_code[0x0c] = (unsigned char)0xff; /* jmp %eax */ + adj_code[0x0d] = (unsigned char)0xe0; + } +#endif + break; + + case 1: /* _ccall */ +#if defined(i386_HOST_ARCH) && !defined(darwin_HOST_OS) + /* 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 + <0f>: ff e0 jmp *%eax # jump to wptr + + The ccall'ing version is a tad different, passing in the return + address of the caller to the auto-generated C stub (which enters + 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 + perform a tail jump instead of a call, followed by some C stack + fixup. + + Note: The adjustor makes the assumption that any return value + 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. + */ + adjustor = stgMallocBytesRWX(17); + { + unsigned char *const adj_code = (unsigned char *)adjustor; + + adj_code[0x00] = (unsigned char)0x68; /* pushl hptr (which is a dword immediate ) */ + *((StgStablePtr*)(adj_code+0x01)) = (StgStablePtr)hptr; + + 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)) = +#if !defined(openbsd_HOST_OS) + (StgFunPtr)obscure_ccall_ret_code; +#else + (StgFunPtr)obscure_ccall_ret_code_dyn; +#endif + + adj_code[0x0f] = (unsigned char)0xff; /* jmp *%eax */ + adj_code[0x10] = (unsigned char)0xe0; + } +#elif defined(i386_HOST_ARCH) && defined(darwin_HOST_OS) + { + /* + What's special about Darwin/Mac OS X on i386? + It wants the stack to stay 16-byte aligned. + + We offload most of the work to AdjustorAsm.S. + */ + AdjustorStub *adjustorStub = stgMallocBytesRWX(sizeof(AdjustorStub)); + adjustor = adjustorStub; + + extern void adjustorCode(void); + int sz = totalArgumentSize(typeString); + + adjustorStub->call[0] = 0xe8; + *(long*)&adjustorStub->call[1] = ((char*)&adjustorCode) - ((char*)adjustorStub + 5); + adjustorStub->hptr = hptr; + adjustorStub->wptr = wptr; + + // The adjustor puts the following things on the stack: + // 1.) %ebp link + // 2.) padding and (a copy of) the arguments + // 3.) a dummy argument + // 4.) hptr + // 5.) return address (for returning to the adjustor) + // All these have to add up to a multiple of 16. + + // first, include everything in frame_size + adjustorStub->frame_size = sz * 4 + 16; + // align to 16 bytes + adjustorStub->frame_size = (adjustorStub->frame_size + 15) & ~15; + // only count 2.) and 3.) as part of frame_size + adjustorStub->frame_size -= 12; + adjustorStub->argument_size = sz; + } + +#elif defined(x86_64_HOST_ARCH) + /* + stack at call: + argn + ... + arg7 + return address + %rdi,%rsi,%rdx,%rcx,%r8,%r9 = arg0..arg6 + + if there are <6 integer args, then we can just push the + StablePtr into %edi and shuffle the other args up. + + If there are >=6 integer args, then we have to flush one arg + to the stack, and arrange to adjust the stack ptr on return. + The stack will be rearranged to this: + + argn + ... + arg7 + return address *** <-- dummy arg in stub fn. + arg6 + obscure_ccall_ret_code + + This unfortunately means that the type of the stub function + must have a dummy argument for the original return address + pointer inserted just after the 6th integer argument. + + Code for the simple case: + + 0: 4d 89 c1 mov %r8,%r9 + 3: 49 89 c8 mov %rcx,%r8 + 6: 48 89 d1 mov %rdx,%rcx + 9: 48 89 f2 mov %rsi,%rdx + c: 48 89 fe mov %rdi,%rsi + f: 48 8b 3d 0a 00 00 00 mov 10(%rip),%rdi + 16: ff 25 0c 00 00 00 jmpq *12(%rip) + ... + 20: .quad 0 # aligned on 8-byte boundary + 28: .quad 0 # aligned on 8-byte boundary + + + And the version for >=6 integer arguments: + + 0: 41 51 push %r9 + 2: ff 35 20 00 00 00 pushq 32(%rip) # 28 <ccall_adjustor+0x28> + 8: 4d 89 c1 mov %r8,%r9 + b: 49 89 c8 mov %rcx,%r8 + e: 48 89 d1 mov %rdx,%rcx + 11: 48 89 f2 mov %rsi,%rdx + 14: 48 89 fe mov %rdi,%rsi + 17: 48 8b 3d 12 00 00 00 mov 18(%rip),%rdi # 30 <ccall_adjustor+0x30> + 1e: ff 25 14 00 00 00 jmpq *20(%rip) # 38 <ccall_adjustor+0x38> + ... + 28: .quad 0 # aligned on 8-byte boundary + 30: .quad 0 # aligned on 8-byte boundary + 38: .quad 0 # aligned on 8-byte boundary + */ + + /* we assume the small code model (gcc -mcmmodel=small) where + * all symbols are <2^32, so hence wptr should fit into 32 bits. + */ + ASSERT(((long)wptr >> 32) == 0); + + { + int i = 0; + char *c; + + // determine whether we have 6 or more integer arguments, + // and therefore need to flush one to the stack. + for (c = typeString; *c != '\0'; c++) { + if (*c == 'i' || *c == 'l') i++; + if (i == 6) break; + } + + if (i < 6) { + adjustor = stgMallocBytesRWX(0x30); + + *(StgInt32 *)adjustor = 0x49c1894d; + *(StgInt32 *)(adjustor+0x4) = 0x8948c889; + *(StgInt32 *)(adjustor+0x8) = 0xf28948d1; + *(StgInt32 *)(adjustor+0xc) = 0x48fe8948; + *(StgInt32 *)(adjustor+0x10) = 0x000a3d8b; + *(StgInt32 *)(adjustor+0x14) = 0x25ff0000; + *(StgInt32 *)(adjustor+0x18) = 0x0000000c; + *(StgInt64 *)(adjustor+0x20) = (StgInt64)hptr; + *(StgInt64 *)(adjustor+0x28) = (StgInt64)wptr; + } + else + { + adjustor = stgMallocBytesRWX(0x40); + + *(StgInt32 *)adjustor = 0x35ff5141; + *(StgInt32 *)(adjustor+0x4) = 0x00000020; + *(StgInt32 *)(adjustor+0x8) = 0x49c1894d; + *(StgInt32 *)(adjustor+0xc) = 0x8948c889; + *(StgInt32 *)(adjustor+0x10) = 0xf28948d1; + *(StgInt32 *)(adjustor+0x14) = 0x48fe8948; + *(StgInt32 *)(adjustor+0x18) = 0x00123d8b; + *(StgInt32 *)(adjustor+0x1c) = 0x25ff0000; + *(StgInt32 *)(adjustor+0x20) = 0x00000014; + + *(StgInt64 *)(adjustor+0x28) = (StgInt64)obscure_ccall_ret_code; + *(StgInt64 *)(adjustor+0x30) = (StgInt64)hptr; + *(StgInt64 *)(adjustor+0x38) = (StgInt64)wptr; + } + } +#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 = stgMallocBytesRWX(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; 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] + */ + ASSERT(((StgWord64)wptr & 3) == 0); + adjustor = stgMallocBytesRWX(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 = stgMallocBytesRWX(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 = stgMallocBytesRWX(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. + sz = totalArgumentSize(typeString); + + // 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). + + 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 adjustor; +} + + +void +freeHaskellFunctionPtr(void* ptr) +{ +#if defined(i386_HOST_ARCH) && !defined(darwin_HOST_OS) + if ( *(unsigned char*)ptr != 0x68 && + *(unsigned char*)ptr != 0x58 ) { + errorBelch("freeHaskellFunctionPtr: not for me, guv! %p\n", ptr); + return; + } + + /* Free the stable pointer first..*/ + if (*(unsigned char*)ptr == 0x68) { /* Aha, a ccall adjustor! */ + freeStablePtr(*((StgStablePtr*)((unsigned char*)ptr + 0x01))); + } else { + freeStablePtr(*((StgStablePtr*)((unsigned char*)ptr + 0x02))); + } +#elif defined(x86_TARGET_ARCH) && defined(darwin_HOST_OS) +if ( *(unsigned char*)ptr != 0xe8 ) { + errorBelch("freeHaskellFunctionPtr: not for me, guv! %p\n", ptr); + return; + } + freeStablePtr(((AdjustorStub*)ptr)->hptr); +#elif defined(x86_64_HOST_ARCH) + if ( *(StgWord16 *)ptr == 0x894d ) { + freeStablePtr(*(StgStablePtr*)(ptr+0x20)); + } else if ( *(StgWord16 *)ptr == 0x5141 ) { + freeStablePtr(*(StgStablePtr*)(ptr+0x30)); + } else { + errorBelch("freeHaskellFunctionPtr: not for me, guv! %p\n", ptr); + return; + } +#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'; + + stgFree(ptr); +} + + +/* + * Function: initAdjustor() + * + * Perform initialisation of adjustor thunk layer (if needed.) + */ +void +initAdjustor(void) +{ +#if defined(i386_HOST_ARCH) && defined(openbsd_HOST_OS) + obscure_ccall_ret_code_dyn = stgMallocBytesRWX(4); + obscure_ccall_ret_code_dyn[0] = ((unsigned char *)obscure_ccall_ret_code)[0]; + obscure_ccall_ret_code_dyn[1] = ((unsigned char *)obscure_ccall_ret_code)[1]; + obscure_ccall_ret_code_dyn[2] = ((unsigned char *)obscure_ccall_ret_code)[2]; + obscure_ccall_ret_code_dyn[3] = ((unsigned char *)obscure_ccall_ret_code)[3]; +#endif +} |