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| author | maxim-yurchuk <[email protected]> | 2024-10-09 12:29:46 +0300 |
|---|---|---|
| committer | maxim-yurchuk <[email protected]> | 2024-10-09 13:14:22 +0300 |
| commit | 9731d8a4bb7ee2cc8554eaf133bb85498a4c7d80 (patch) | |
| tree | a8fb3181d5947c0d78cf402aa56e686130179049 /contrib/libs/cxxsupp/builtins/enable_execute_stack.c | |
| parent | a44b779cd359f06c3ebbef4ec98c6b38609d9d85 (diff) | |
publishFullContrib: true for ydb
<HIDDEN_URL>
commit_hash:c82a80ac4594723cebf2c7387dec9c60217f603e
Diffstat (limited to 'contrib/libs/cxxsupp/builtins/enable_execute_stack.c')
| -rw-r--r-- | contrib/libs/cxxsupp/builtins/enable_execute_stack.c | 72 |
1 files changed, 72 insertions, 0 deletions
diff --git a/contrib/libs/cxxsupp/builtins/enable_execute_stack.c b/contrib/libs/cxxsupp/builtins/enable_execute_stack.c new file mode 100644 index 00000000000..0dc3482c446 --- /dev/null +++ b/contrib/libs/cxxsupp/builtins/enable_execute_stack.c @@ -0,0 +1,72 @@ +/* ===-- enable_execute_stack.c - Implement __enable_execute_stack ---------=== + * + * The LLVM Compiler Infrastructure + * + * This file is dual licensed under the MIT and the University of Illinois Open + * Source Licenses. See LICENSE.TXT for details. + * + * ===----------------------------------------------------------------------=== + */ + +#include "int_lib.h" + +#ifndef _WIN32 +#include <sys/mman.h> +#endif + +/* #include "config.h" + * FIXME: CMake - include when cmake system is ready. + * Remove #define HAVE_SYSCONF 1 line. + */ +#define HAVE_SYSCONF 1 + +#ifdef _WIN32 +#define WIN32_LEAN_AND_MEAN +#include <Windows.h> +#else +#ifndef __APPLE__ +#include <unistd.h> +#endif /* __APPLE__ */ +#endif /* _WIN32 */ + +#if __LP64__ + #define TRAMPOLINE_SIZE 48 +#else + #define TRAMPOLINE_SIZE 40 +#endif + +/* + * 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 + * and the next 48 bytes as executable. Since the stack is normally rw- + * that means changing the protection on those page(s) to rwx. + */ + +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); +#else +#if __APPLE__ + /* 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); +#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); +#endif +} |
