llvm/compiler-rt/lib/safestack/safestack_platform.h

//===-- safestack_platform.h ----------------------------------------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
//
// This file implements platform specific parts of SafeStack runtime.
// Don't use equivalent functionality from sanitizer_common to avoid dragging
// a large codebase into security sensitive code.
//
//===----------------------------------------------------------------------===//

#ifndef SAFESTACK_PLATFORM_H
#define SAFESTACK_PLATFORM_H

#include "safestack_util.h"
#include "sanitizer_common/sanitizer_platform.h"

#include <dlfcn.h>
#include <errno.h>
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <sys/mman.h>
#include <sys/syscall.h>
#include <sys/types.h>
#include <unistd.h>

#if !(SANITIZER_NETBSD || SANITIZER_FREEBSD || SANITIZER_LINUX || \
      SANITIZER_SOLARIS)
#  error "Support for your platform has not been implemented"
#endif

#if SANITIZER_NETBSD
#include <lwp.h>

extern "C" void *__mmap(void *, size_t, int, int, int, int, off_t);
#endif

#if SANITIZER_FREEBSD
#include <sys/thr.h>
#endif

#if SANITIZER_SOLARIS
#  include <thread.h>
#endif

// Keep in sync with sanitizer_linux.cpp.
//
// Are we using 32-bit or 64-bit Linux syscalls?
// x32 (which defines __x86_64__) has SANITIZER_WORDSIZE == 32
// but it still needs to use 64-bit syscalls.
#if SANITIZER_LINUX &&                                \
    (defined(__x86_64__) || defined(__powerpc64__) || \
     SANITIZER_WORDSIZE == 64 || (defined(__mips__) && _MIPS_SIM == _ABIN32))
#define SANITIZER_LINUX_USES_64BIT_SYSCALLS …
#else
#define SANITIZER_LINUX_USES_64BIT_SYSCALLS …
#endif

namespace safestack {

#if SANITIZER_NETBSD
static void *GetRealLibcAddress(const char *symbol) {
  void *real = dlsym(RTLD_NEXT, symbol);
  if (!real)
    real = dlsym(RTLD_DEFAULT, symbol);
  if (!real) {
    fprintf(stderr, "safestack GetRealLibcAddress failed for symbol=%s",
            symbol);
    abort();
  }
  return real;
}

#define _REAL …
#define DEFINE__REAL …
#endif

#if SANITIZER_SOLARIS
#define _REAL …
#define DEFINE__REAL …

#  if !defined(_LP64) && _FILE_OFFSET_BITS == 64
#define _REAL64 …
#  else
#define _REAL64 …
#  endif
#define DEFINE__REAL64 …

DEFINE__REAL64(void *, mmap, void *a, size_t b, int c, int d, int e, off_t f);
DEFINE__REAL(int, munmap, void *a, size_t b);
DEFINE__REAL(int, mprotect, void *a, size_t b, int c);
#endif

ThreadId;

inline ThreadId GetTid() { … }

inline int TgKill(pid_t pid, ThreadId tid, int sig) { … }

inline void *Mmap(void *addr, size_t length, int prot, int flags, int fd,
                  off_t offset) { … }

inline int Munmap(void *addr, size_t length) { … }

inline int Mprotect(void *addr, size_t length, int prot) { … }

}  // namespace safestack

#endif  // SAFESTACK_PLATFORM_H