llvm/compiler-rt/lib/sanitizer_common/sanitizer_linux.h

//===-- sanitizer_linux.h ---------------------------------------*- C++ -*-===//
//
// 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
//
//===----------------------------------------------------------------------===//
//
// Linux-specific syscall wrappers and classes.
//
//===----------------------------------------------------------------------===//
#ifndef SANITIZER_LINUX_H
#define SANITIZER_LINUX_H

#include "sanitizer_platform.h"
#if SANITIZER_FREEBSD || SANITIZER_LINUX || SANITIZER_NETBSD || \
    SANITIZER_SOLARIS
#  include "sanitizer_common.h"
#  include "sanitizer_internal_defs.h"
#  include "sanitizer_platform_limits_freebsd.h"
#  include "sanitizer_platform_limits_netbsd.h"
#  include "sanitizer_platform_limits_posix.h"
#  include "sanitizer_platform_limits_solaris.h"
#  include "sanitizer_posix.h"

struct link_map;  // Opaque type returned by dlopen().
struct utsname;

namespace __sanitizer {
// Dirent structure for getdents(). Note that this structure is different from
// the one in <dirent.h>, which is used by readdir().
struct linux_dirent;

struct ProcSelfMapsBuff { … };

struct MemoryMappingLayoutData { … };

void ReadProcMaps(ProcSelfMapsBuff *proc_maps);

// Syscall wrappers.
uptr internal_getdents(fd_t fd, struct linux_dirent *dirp, unsigned int count);
uptr internal_sigaltstack(const void *ss, void *oss);
uptr internal_sigprocmask(int how, __sanitizer_sigset_t *set,
                          __sanitizer_sigset_t *oldset);

void SetSigProcMask(__sanitizer_sigset_t *set, __sanitizer_sigset_t *oldset);
void BlockSignals(__sanitizer_sigset_t *oldset = nullptr);
struct ScopedBlockSignals { … };

#  if SANITIZER_GLIBC
uptr internal_clock_gettime(__sanitizer_clockid_t clk_id, void *tp);
#  endif

// Linux-only syscalls.
#  if SANITIZER_LINUX
uptr internal_prctl(int option, uptr arg2, uptr arg3, uptr arg4, uptr arg5);
#    if defined(__x86_64__)
uptr internal_arch_prctl(int option, uptr arg2);
#    endif
// Used only by sanitizer_stoptheworld. Signal handlers that are actually used
// (like the process-wide error reporting SEGV handler) must use
// internal_sigaction instead.
int internal_sigaction_norestorer(int signum, const void *act, void *oldact);
void internal_sigdelset(__sanitizer_sigset_t *set, int signum);
#    if defined(__x86_64__) || defined(__mips__) || defined(__aarch64__) || \
        defined(__powerpc64__) || defined(__s390__) || defined(__i386__) || \
        defined(__arm__) || SANITIZER_RISCV64 || SANITIZER_LOONGARCH64
uptr internal_clone(int (*fn)(void *), void *child_stack, int flags, void *arg,
                    int *parent_tidptr, void *newtls, int *child_tidptr);
#    endif
int internal_uname(struct utsname *buf);
#  elif SANITIZER_FREEBSD
uptr internal_procctl(int type, int id, int cmd, void *data);
void internal_sigdelset(__sanitizer_sigset_t *set, int signum);
#  elif SANITIZER_NETBSD
void internal_sigdelset(__sanitizer_sigset_t *set, int signum);
uptr internal_clone(int (*fn)(void *), void *child_stack, int flags, void *arg);
#  endif  // SANITIZER_LINUX

// This class reads thread IDs from /proc/<pid>/task using only syscalls.
class ThreadLister { … };

// Exposed for testing.
uptr ThreadDescriptorSize();
uptr ThreadSelf();

// Matches a library's file name against a base name (stripping path and version
// information).
bool LibraryNameIs(const char *full_name, const char *base_name);

// Call cb for each region mapped by map.
void ForEachMappedRegion(link_map *map, void (*cb)(const void *, uptr));

// Releases memory pages entirely within the [beg, end] address range.
// The pages no longer count toward RSS; reads are guaranteed to return 0.
// Requires (but does not verify!) that pages are MAP_PRIVATE.
inline void ReleaseMemoryPagesToOSAndZeroFill(uptr beg, uptr end) { … }

#  if SANITIZER_ANDROID

#    if defined(__aarch64__)
#define __get_tls …
#    elif defined(__arm__)
#define __get_tls …
#    elif defined(__mips__)
// On mips32r1, this goes via a kernel illegal instruction trap that's
// optimized for v1.
#define __get_tls …
#    elif defined(__riscv)
#define __get_tls …
#    elif defined(__i386__)
#define __get_tls …
#    elif defined(__x86_64__)
#define __get_tls …
#    else
#      error "Unsupported architecture."
#    endif

// The Android Bionic team has allocated a TLS slot for sanitizers starting
// with Q, given that Android currently doesn't support ELF TLS. It is used to
// store sanitizer thread specific data.
static const int TLS_SLOT_SANITIZER = 6;

ALWAYS_INLINE uptr *get_android_tls_ptr() {
  return reinterpret_cast<uptr *>(&__get_tls()[TLS_SLOT_SANITIZER]);
}

#  endif  // SANITIZER_ANDROID

}  // namespace __sanitizer

#endif
#endif  // SANITIZER_LINUX_H