X-Git-Url: http://git.megacz.com/?a=blobdiff_plain;f=ghc%2Frts%2FAdjustor.c;h=c6729163171fb5066c78d92bc67e61a136c6352f;hb=4b17256112ecbee54dd4437f29c711bbfae239c7;hp=bf1002d927bac3271436d9783a2016aa6c79ba19;hpb=3bb535af4751025d75afa89d3f410554f4071a9f;p=ghc-hetmet.git diff --git a/ghc/rts/Adjustor.c b/ghc/rts/Adjustor.c index bf1002d..c672916 100644 --- a/ghc/rts/Adjustor.c +++ b/ghc/rts/Adjustor.c @@ -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" @@ -48,53 +48,46 @@ Haskell side. #if defined(openbsd_TARGET_OS) #include +#include #include + +/* no C99 header stdint.h on OpenBSD? */ +typedef unsigned long my_uintptr_t; #endif /* Heavily arch-specific, I'm afraid.. */ -typedef enum { - pageExecuteRead, - pageExecuteReadWrite -} pageMode; - /* - * 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 - -#if defined(openbsd_TARGET_OS) - /* malloc memory isn't executable by default on OpenBSD */ - unsigned long pagesize = sysconf(_SC_PAGESIZE); - unsigned long round = (unsigned long)addr & (pagesize - 1); - if (mprotect(addr - round, pagesize, PROT_EXEC|PROT_READ|PROT_WRITE) == -1) - barf("execPage: failed to protect 0x%p\n", addr); -#endif - - (void)addr; (void)mode; /* keep gcc -Wall happy */ + void *addr = stgMallocBytes(len, "mallocBytesRWX"); +#if defined(i386_TARGET_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_TARGET_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) @@ -162,7 +155,7 @@ createAdjustor(int cconv, StgStablePtr hptr, StgFunPtr wptr) : 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 */ @@ -177,8 +170,6 @@ 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; @@ -209,7 +200,7 @@ 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; @@ -224,8 +215,6 @@ 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) /* Magic constant computed by inspecting the code length of the following @@ -257,7 +246,7 @@ 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; @@ -334,7 +323,7 @@ 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; @@ -372,7 +361,7 @@ TODO: Depending on how much allocation overhead stgMallocBytes uses for 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"); + adjustor = mallocBytesRWX(4*13); { unsigned long *const adj_code = (unsigned long *)adjustor; @@ -593,14 +582,12 @@ 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 }