diff options
| -rw-r--r-- | rts/linker/MMap.c | 48 | ||||
| -rw-r--r-- | rts/linker/MMap.h | 2 |
2 files changed, 39 insertions, 11 deletions
diff --git a/rts/linker/MMap.c b/rts/linker/MMap.c index 2d6c2aa148..30abad106e 100644 --- a/rts/linker/MMap.c +++ b/rts/linker/MMap.c @@ -46,6 +46,8 @@ static const char *memoryAccessDescription(MemoryAccess mode) case MEM_NO_ACCESS: return "no-access"; case MEM_READ_ONLY: return "read-only"; case MEM_READ_WRITE: return "read-write"; + case MEM_READ_WRITE_THEN_READ_EXECUTE: + return "read-write-then-read-execute"; case MEM_READ_EXECUTE: return "read-execute"; case MEM_READ_WRITE_EXECUTE: return "read-write-execute"; @@ -63,13 +65,6 @@ struct MemoryRegion { */ }; -#define LOW_ADDR 0x01000000 -static struct MemoryRegion allMemory = { - .start = (void *) LOW_ADDR, - .end = (void *) -1, - .last = (void *) LOW_ADDR -}; - #if defined(mingw32_HOST_OS) /* A wrapper for VirtualQuery() providing useful debug output */ @@ -196,6 +191,8 @@ memoryAccessToProt(MemoryAccess access) case MEM_NO_ACCESS: return PAGE_NOACCESS; case MEM_READ_ONLY: return PAGE_READONLY; case MEM_READ_WRITE: return PAGE_READWRITE; + case MEM_READ_WRITE_THEN_READ_EXECUTE: + return PAGE_READWRITE; case MEM_READ_EXECUTE: return PAGE_EXECUTE_READ; case MEM_READ_WRITE_EXECUTE: return PAGE_EXECUTE_READWRITE; @@ -258,6 +255,17 @@ memoryAccessToProt(MemoryAccess access) case MEM_NO_ACCESS: return 0; case MEM_READ_ONLY: return PROT_READ; case MEM_READ_WRITE: return PROT_READ | PROT_WRITE; + case MEM_READ_WRITE_THEN_READ_EXECUTE: +# if defined(netbsd_HOST_OS) + /* PROT_MPROTECT(PROT_EXEC) means that the pages are going to be + * marked as executable in the future. On NetBSD requesting + * additional permissions with mprotect(2) only succeeds when + * permissions were initially requested in this manner. + */ + return PROT_READ | PROT_WRITE | PROT_MPROTECT(PROT_EXEC); +# else + return PROT_READ | PROT_WRITE; +# endif case MEM_READ_EXECUTE: return PROT_READ | PROT_EXEC; case MEM_READ_WRITE_EXECUTE: return PROT_READ | PROT_WRITE | PROT_EXEC; @@ -302,6 +310,18 @@ nearImage(void) { } static void * +mmapAnywhere ( + size_t bytes, + MemoryAccess access, + uint32_t flags, + int fd, + int offset) +{ + int prot = memoryAccessToProt(access); + return doMmap(NULL, bytes, prot, flags, fd, offset); +} + +static void * mmapInRegion ( struct MemoryRegion *region, size_t bytes, @@ -358,17 +378,23 @@ mmapForLinker (size_t bytes, MemoryAccess access, uint32_t flags, int fd, int of IF_DEBUG(linker_verbose, debugBelch("mmapForLinker: start\n")); if (RtsFlags.MiscFlags.linkerAlwaysPic) { /* make no attempt at mapping low memory if we are assuming PIC */ - region = &allMemory; + region = NULL; } else { region = nearImage(); } /* Use MAP_32BIT if appropriate */ - if (region->end <= (void *) 0xffffffff) { + if (region && region->end <= (void *) 0xffffffff) { flags |= TRY_MAP_32BIT; } - void *result = mmapInRegion(region, bytes, access, flags, fd, offset); + void *result; + if (region) { + result = mmapInRegion(region, bytes, access, flags, fd, offset); + } + else { + result = mmapAnywhere(bytes, access, flags, fd, offset); + } IF_DEBUG(linker_verbose, debugBelch("mmapForLinker: mapped %zd bytes starting at %p\n", bytes, result)); @@ -383,7 +409,7 @@ mmapForLinker (size_t bytes, MemoryAccess access, uint32_t flags, int fd, int of void * mmapAnonForLinker (size_t bytes) { - return mmapForLinker (bytes, MEM_READ_WRITE, MAP_ANONYMOUS, -1, 0); + return mmapForLinker (bytes, MEM_READ_WRITE_THEN_READ_EXECUTE, MAP_ANONYMOUS, -1, 0); } void munmapForLinker (void *addr, size_t bytes, const char *caller) diff --git a/rts/linker/MMap.h b/rts/linker/MMap.h index 9eebc3c4b2..683ec1f6ea 100644 --- a/rts/linker/MMap.h +++ b/rts/linker/MMap.h @@ -54,6 +54,8 @@ typedef enum { MEM_NO_ACCESS, MEM_READ_ONLY, MEM_READ_WRITE, + // Initially map pages as rw- and then switch to r-x later. + MEM_READ_WRITE_THEN_READ_EXECUTE, MEM_READ_EXECUTE, MEM_READ_WRITE_EXECUTE, } MemoryAccess; |