//===-- 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 , which is used by readdir(). struct linux_dirent; struct ProcSelfMapsBuff { char *data; uptr mmaped_size; uptr len; }; struct MemoryMappingLayoutData { ProcSelfMapsBuff proc_self_maps; const char *current; }; 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 { explicit ScopedBlockSignals(__sanitizer_sigset_t *copy); ~ScopedBlockSignals(); ScopedBlockSignals &operator=(const ScopedBlockSignals &) = delete; ScopedBlockSignals(const ScopedBlockSignals &) = delete; private: __sanitizer_sigset_t saved_; }; # 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//task using only syscalls. class ThreadLister { public: explicit ThreadLister(pid_t pid); ~ThreadLister(); enum Result { Error, Incomplete, Ok, }; Result ListThreads(InternalMmapVector *threads); private: bool IsAlive(int tid); pid_t pid_; int descriptor_ = -1; InternalMmapVector buffer_; }; // 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) { // man madvise on Linux promises zero-fill for anonymous private pages. // Testing shows the same behaviour for private (but not anonymous) mappings // of shm_open() files, as long as the underlying file is untouched. CHECK(SANITIZER_LINUX); ReleaseMemoryPagesToOS(beg, end); } # if SANITIZER_ANDROID # if defined(__aarch64__) # define __get_tls() \ ({ \ void **__v; \ __asm__("mrs %0, tpidr_el0" : "=r"(__v)); \ __v; \ }) # elif defined(__arm__) # define __get_tls() \ ({ \ void **__v; \ __asm__("mrc p15, 0, %0, c13, c0, 3" : "=r"(__v)); \ __v; \ }) # elif defined(__mips__) // On mips32r1, this goes via a kernel illegal instruction trap that's // optimized for v1. # define __get_tls() \ ({ \ register void **__v asm("v1"); \ __asm__( \ ".set push\n" \ ".set mips32r2\n" \ "rdhwr %0,$29\n" \ ".set pop\n" \ : "=r"(__v)); \ __v; \ }) # elif defined(__riscv) # define __get_tls() \ ({ \ void **__v; \ __asm__("mv %0, tp" : "=r"(__v)); \ __v; \ }) # elif defined(__i386__) # define __get_tls() \ ({ \ void **__v; \ __asm__("movl %%gs:0, %0" : "=r"(__v)); \ __v; \ }) # elif defined(__x86_64__) # define __get_tls() \ ({ \ void **__v; \ __asm__("mov %%fs:0, %0" : "=r"(__v)); \ __v; \ }) # 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(&__get_tls()[TLS_SLOT_SANITIZER]); } # endif // SANITIZER_ANDROID } // namespace __sanitizer #endif #endif // SANITIZER_LINUX_H