diff options
Diffstat (limited to 'compiler-rt/lib/builtins/enable_execute_stack.c')
| -rw-r--r-- | compiler-rt/lib/builtins/enable_execute_stack.c | 43 |
1 files changed, 22 insertions, 21 deletions
diff --git a/compiler-rt/lib/builtins/enable_execute_stack.c b/compiler-rt/lib/builtins/enable_execute_stack.c index 1318ea92c82..d1ad90bf9d5 100644 --- a/compiler-rt/lib/builtins/enable_execute_stack.c +++ b/compiler-rt/lib/builtins/enable_execute_stack.c @@ -29,43 +29,44 @@ #endif /* _WIN32 */ #if __LP64__ - #define TRAMPOLINE_SIZE 48 +#define TRAMPOLINE_SIZE 48 #else - #define TRAMPOLINE_SIZE 40 +#define TRAMPOLINE_SIZE 40 #endif /* - * The compiler generates calls to __enable_execute_stack() when creating + * The compiler generates calls to __enable_execute_stack() when creating * trampoline functions on the stack for use with nested functions. - * It is expected to mark the page(s) containing the address + * It is expected to mark the page(s) containing the address * and the next 48 bytes as executable. Since the stack is normally rw- - * that means changing the protection on those page(s) to rwx. + * that means changing the protection on those page(s) to rwx. */ -COMPILER_RT_ABI void -__enable_execute_stack(void* addr) -{ +COMPILER_RT_ABI void __enable_execute_stack(void *addr) { #if _WIN32 - MEMORY_BASIC_INFORMATION mbi; - if (!VirtualQuery (addr, &mbi, sizeof(mbi))) - return; /* We should probably assert here because there is no return value */ - VirtualProtect (mbi.BaseAddress, mbi.RegionSize, PAGE_EXECUTE_READWRITE, &mbi.Protect); + MEMORY_BASIC_INFORMATION mbi; + if (!VirtualQuery(addr, &mbi, sizeof(mbi))) + return; /* We should probably assert here because there is no return value + */ + VirtualProtect(mbi.BaseAddress, mbi.RegionSize, PAGE_EXECUTE_READWRITE, + &mbi.Protect); #else #if __APPLE__ - /* On Darwin, pagesize is always 4096 bytes */ - const uintptr_t pageSize = 4096; + /* On Darwin, pagesize is always 4096 bytes */ + const uintptr_t pageSize = 4096; #elif !defined(HAVE_SYSCONF) #error "HAVE_SYSCONF not defined! See enable_execute_stack.c" #else - const uintptr_t pageSize = sysconf(_SC_PAGESIZE); + const uintptr_t pageSize = sysconf(_SC_PAGESIZE); #endif /* __APPLE__ */ - const uintptr_t pageAlignMask = ~(pageSize-1); - uintptr_t p = (uintptr_t)addr; - unsigned char* startPage = (unsigned char*)(p & pageAlignMask); - unsigned char* endPage = (unsigned char*)((p+TRAMPOLINE_SIZE+pageSize) & pageAlignMask); - size_t length = endPage - startPage; - (void) mprotect((void *)startPage, length, PROT_READ | PROT_WRITE | PROT_EXEC); + const uintptr_t pageAlignMask = ~(pageSize - 1); + uintptr_t p = (uintptr_t)addr; + unsigned char *startPage = (unsigned char *)(p & pageAlignMask); + unsigned char *endPage = + (unsigned char *)((p + TRAMPOLINE_SIZE + pageSize) & pageAlignMask); + size_t length = endPage - startPage; + (void)mprotect((void *)startPage, length, PROT_READ | PROT_WRITE | PROT_EXEC); #endif } |
