1b3a6901e66f55b35aa9e01bcb24134e6a65ea004Daniel Dunbar//===-- enable_execute_stack_test.c - Test __enable_execute_stack ----------===// 2b3a6901e66f55b35aa9e01bcb24134e6a65ea004Daniel Dunbar// 3b3a6901e66f55b35aa9e01bcb24134e6a65ea004Daniel Dunbar// The LLVM Compiler Infrastructure 4b3a6901e66f55b35aa9e01bcb24134e6a65ea004Daniel Dunbar// 59ad441ffec97db647fee3725b3424284fb913e14Howard Hinnant// This file is dual licensed under the MIT and the University of Illinois Open 69ad441ffec97db647fee3725b3424284fb913e14Howard Hinnant// Source Licenses. See LICENSE.TXT for details. 7b3a6901e66f55b35aa9e01bcb24134e6a65ea004Daniel Dunbar// 8b3a6901e66f55b35aa9e01bcb24134e6a65ea004Daniel Dunbar//===----------------------------------------------------------------------===// 9b3a6901e66f55b35aa9e01bcb24134e6a65ea004Daniel Dunbar 10b3a6901e66f55b35aa9e01bcb24134e6a65ea004Daniel Dunbar 11b3a6901e66f55b35aa9e01bcb24134e6a65ea004Daniel Dunbar#include <stdio.h> 12b3a6901e66f55b35aa9e01bcb24134e6a65ea004Daniel Dunbar#include <string.h> 13b3a6901e66f55b35aa9e01bcb24134e6a65ea004Daniel Dunbar#include <stdint.h> 147e8904f4b2b6b084ea2b4203d62554b42c068296Anton Korobeynikov#if defined(_WIN32) 157e8904f4b2b6b084ea2b4203d62554b42c068296Anton Korobeynikov#include <windows.h> 167e8904f4b2b6b084ea2b4203d62554b42c068296Anton Korobeynikovvoid __clear_cache(void* start, void* end) 177e8904f4b2b6b084ea2b4203d62554b42c068296Anton Korobeynikov{ 187e8904f4b2b6b084ea2b4203d62554b42c068296Anton Korobeynikov if (!FlushInstructionCache(GetCurrentProcess(), start, end-start)) 197e8904f4b2b6b084ea2b4203d62554b42c068296Anton Korobeynikov exit(1); 207e8904f4b2b6b084ea2b4203d62554b42c068296Anton Korobeynikov} 217e8904f4b2b6b084ea2b4203d62554b42c068296Anton Korobeynikovvoid __enable_execute_stack(void *addr) 227e8904f4b2b6b084ea2b4203d62554b42c068296Anton Korobeynikov{ 237e8904f4b2b6b084ea2b4203d62554b42c068296Anton Korobeynikov MEMORY_BASIC_INFORMATION b; 24b3a6901e66f55b35aa9e01bcb24134e6a65ea004Daniel Dunbar 257e8904f4b2b6b084ea2b4203d62554b42c068296Anton Korobeynikov if (!VirtualQuery(addr, &b, sizeof(b))) 267e8904f4b2b6b084ea2b4203d62554b42c068296Anton Korobeynikov exit(1); 277e8904f4b2b6b084ea2b4203d62554b42c068296Anton Korobeynikov if (!VirtualProtect(b.BaseAddress, b.RegionSize, PAGE_EXECUTE_READWRITE, &b.Protect)) 287e8904f4b2b6b084ea2b4203d62554b42c068296Anton Korobeynikov exit(1); 297e8904f4b2b6b084ea2b4203d62554b42c068296Anton Korobeynikov} 307e8904f4b2b6b084ea2b4203d62554b42c068296Anton Korobeynikov#else 317e8904f4b2b6b084ea2b4203d62554b42c068296Anton Korobeynikov#include <sys/mman.h> 32b3a6901e66f55b35aa9e01bcb24134e6a65ea004Daniel Dunbarextern void __clear_cache(void* start, void* end); 33b3a6901e66f55b35aa9e01bcb24134e6a65ea004Daniel Dunbarextern void __enable_execute_stack(void* addr); 347e8904f4b2b6b084ea2b4203d62554b42c068296Anton Korobeynikov#endif 35b3a6901e66f55b35aa9e01bcb24134e6a65ea004Daniel Dunbar 36b3a6901e66f55b35aa9e01bcb24134e6a65ea004Daniel Dunbartypedef int (*pfunc)(void); 37b3a6901e66f55b35aa9e01bcb24134e6a65ea004Daniel Dunbar 38b3a6901e66f55b35aa9e01bcb24134e6a65ea004Daniel Dunbarint func1() 39b3a6901e66f55b35aa9e01bcb24134e6a65ea004Daniel Dunbar{ 40b3a6901e66f55b35aa9e01bcb24134e6a65ea004Daniel Dunbar return 1; 41b3a6901e66f55b35aa9e01bcb24134e6a65ea004Daniel Dunbar} 42b3a6901e66f55b35aa9e01bcb24134e6a65ea004Daniel Dunbar 43b3a6901e66f55b35aa9e01bcb24134e6a65ea004Daniel Dunbarint func2() 44b3a6901e66f55b35aa9e01bcb24134e6a65ea004Daniel Dunbar{ 45b3a6901e66f55b35aa9e01bcb24134e6a65ea004Daniel Dunbar return 2; 46b3a6901e66f55b35aa9e01bcb24134e6a65ea004Daniel Dunbar} 47b3a6901e66f55b35aa9e01bcb24134e6a65ea004Daniel Dunbar 4886277eb844c4983c81de62d7c050e92fe7155788Stephen Hinesvoid *__attribute__((noinline)) 4986277eb844c4983c81de62d7c050e92fe7155788Stephen Hinesmemcpy_f(void *dst, const void *src, size_t n) { 5086277eb844c4983c81de62d7c050e92fe7155788Stephen Hines// ARM and MIPS nartually align functions, but use the LSB for ISA selection 5186277eb844c4983c81de62d7c050e92fe7155788Stephen Hines// (THUMB, MIPS16/uMIPS respectively). Ensure that the ISA bit is ignored in 5286277eb844c4983c81de62d7c050e92fe7155788Stephen Hines// the memcpy 5386277eb844c4983c81de62d7c050e92fe7155788Stephen Hines#if defined(__arm__) || defined(__mips__) 5486277eb844c4983c81de62d7c050e92fe7155788Stephen Hines return (void *)((uintptr_t)memcpy(dst, (void *)((uintptr_t)src & ~1), n) | 5586277eb844c4983c81de62d7c050e92fe7155788Stephen Hines ((uintptr_t)src & 1)); 5686277eb844c4983c81de62d7c050e92fe7155788Stephen Hines#else 5786277eb844c4983c81de62d7c050e92fe7155788Stephen Hines return memcpy(dst, (void *)((uintptr_t)src), n); 5886277eb844c4983c81de62d7c050e92fe7155788Stephen Hines#endif 5986277eb844c4983c81de62d7c050e92fe7155788Stephen Hines} 60b3a6901e66f55b35aa9e01bcb24134e6a65ea004Daniel Dunbar 61b3a6901e66f55b35aa9e01bcb24134e6a65ea004Daniel Dunbarint main() 62b3a6901e66f55b35aa9e01bcb24134e6a65ea004Daniel Dunbar{ 63a07fa29cead05031869b7488f4e845584e57b628Shantonu Sen unsigned char execution_buffer[128]; 64a07fa29cead05031869b7488f4e845584e57b628Shantonu Sen // mark stack page containing execution_buffer to be executable 65a07fa29cead05031869b7488f4e845584e57b628Shantonu Sen __enable_execute_stack(execution_buffer); 66b3a6901e66f55b35aa9e01bcb24134e6a65ea004Daniel Dunbar 67b3a6901e66f55b35aa9e01bcb24134e6a65ea004Daniel Dunbar // verify you can copy and execute a function 6886277eb844c4983c81de62d7c050e92fe7155788Stephen Hines pfunc f1 = (pfunc)memcpy_f(execution_buffer, func1, 128); 69b3a6901e66f55b35aa9e01bcb24134e6a65ea004Daniel Dunbar __clear_cache(execution_buffer, &execution_buffer[128]); 707e8904f4b2b6b084ea2b4203d62554b42c068296Anton Korobeynikov if ((*f1)() != 1) 71b3a6901e66f55b35aa9e01bcb24134e6a65ea004Daniel Dunbar return 1; 72b3a6901e66f55b35aa9e01bcb24134e6a65ea004Daniel Dunbar 73b3a6901e66f55b35aa9e01bcb24134e6a65ea004Daniel Dunbar // verify you can overwrite a function with another 7486277eb844c4983c81de62d7c050e92fe7155788Stephen Hines pfunc f2 = (pfunc)memcpy_f(execution_buffer, func2, 128); 75b3a6901e66f55b35aa9e01bcb24134e6a65ea004Daniel Dunbar __clear_cache(execution_buffer, &execution_buffer[128]); 767e8904f4b2b6b084ea2b4203d62554b42c068296Anton Korobeynikov if ((*f2)() != 2) 77b3a6901e66f55b35aa9e01bcb24134e6a65ea004Daniel Dunbar return 1; 78b3a6901e66f55b35aa9e01bcb24134e6a65ea004Daniel Dunbar 79b3a6901e66f55b35aa9e01bcb24134e6a65ea004Daniel Dunbar return 0; 80b3a6901e66f55b35aa9e01bcb24134e6a65ea004Daniel Dunbar} 81