forked from OSchip/llvm-project
709 lines
22 KiB
C++
709 lines
22 KiB
C++
//===-- sanitizer_linux.cc ------------------------------------------------===//
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//
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// The LLVM Compiler Infrastructure
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//
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// This file is distributed under the University of Illinois Open Source
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// License. See LICENSE.TXT for details.
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//
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//===----------------------------------------------------------------------===//
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//
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// This file is shared between AddressSanitizer and ThreadSanitizer
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// run-time libraries and implements linux-specific functions from
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// sanitizer_libc.h.
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//===----------------------------------------------------------------------===//
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#include "sanitizer_platform.h"
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#if SANITIZER_LINUX
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#include "sanitizer_common.h"
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#include "sanitizer_flags.h"
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#include "sanitizer_internal_defs.h"
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#include "sanitizer_libc.h"
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#include "sanitizer_linux.h"
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#include "sanitizer_mutex.h"
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#include "sanitizer_placement_new.h"
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#include "sanitizer_procmaps.h"
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#include "sanitizer_stacktrace.h"
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#include "sanitizer_symbolizer.h"
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#include <asm/param.h>
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#include <dlfcn.h>
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#include <errno.h>
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#include <fcntl.h>
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#if !SANITIZER_ANDROID
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#include <link.h>
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#endif
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#include <pthread.h>
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#include <sched.h>
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#include <sys/mman.h>
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#include <sys/ptrace.h>
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#include <sys/resource.h>
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#include <sys/stat.h>
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#include <sys/syscall.h>
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#include <sys/time.h>
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#include <sys/types.h>
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#include <unistd.h>
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#include <unwind.h>
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#if !SANITIZER_ANDROID
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#include <sys/signal.h>
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#endif
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#if SANITIZER_ANDROID
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#include <android/log.h>
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#endif
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// <linux/time.h>
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struct kernel_timeval {
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long tv_sec;
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long tv_usec;
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};
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// <linux/futex.h> is broken on some linux distributions.
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const int FUTEX_WAIT = 0;
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const int FUTEX_WAKE = 1;
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// Are we using 32-bit or 64-bit syscalls?
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// x32 (which defines __x86_64__) has SANITIZER_WORDSIZE == 32
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// but it still needs to use 64-bit syscalls.
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#if defined(__x86_64__) || SANITIZER_WORDSIZE == 64
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# define SANITIZER_LINUX_USES_64BIT_SYSCALLS 1
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#else
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# define SANITIZER_LINUX_USES_64BIT_SYSCALLS 0
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#endif
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namespace __sanitizer {
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#ifdef __x86_64__
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#include "sanitizer_syscall_linux_x86_64.inc"
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#else
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#include "sanitizer_syscall_generic.inc"
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#endif
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// --------------- sanitizer_libc.h
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uptr internal_mmap(void *addr, uptr length, int prot, int flags,
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int fd, u64 offset) {
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#if SANITIZER_LINUX_USES_64BIT_SYSCALLS
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return internal_syscall(__NR_mmap, (uptr)addr, length, prot, flags, fd,
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offset);
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#else
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return internal_syscall(__NR_mmap2, addr, length, prot, flags, fd, offset);
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#endif
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}
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uptr internal_munmap(void *addr, uptr length) {
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return internal_syscall(__NR_munmap, (uptr)addr, length);
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}
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uptr internal_close(fd_t fd) {
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return internal_syscall(__NR_close, fd);
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}
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uptr internal_open(const char *filename, int flags) {
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return internal_syscall(__NR_open, (uptr)filename, flags);
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}
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uptr internal_open(const char *filename, int flags, u32 mode) {
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return internal_syscall(__NR_open, (uptr)filename, flags, mode);
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}
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uptr OpenFile(const char *filename, bool write) {
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return internal_open(filename,
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write ? O_WRONLY | O_CREAT /*| O_CLOEXEC*/ : O_RDONLY, 0660);
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}
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uptr internal_read(fd_t fd, void *buf, uptr count) {
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sptr res;
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HANDLE_EINTR(res, (sptr)internal_syscall(__NR_read, fd, (uptr)buf, count));
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return res;
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}
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uptr internal_write(fd_t fd, const void *buf, uptr count) {
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sptr res;
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HANDLE_EINTR(res, (sptr)internal_syscall(__NR_write, fd, (uptr)buf, count));
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return res;
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}
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#if !SANITIZER_LINUX_USES_64BIT_SYSCALLS
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static void stat64_to_stat(struct stat64 *in, struct stat *out) {
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internal_memset(out, 0, sizeof(*out));
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out->st_dev = in->st_dev;
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out->st_ino = in->st_ino;
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out->st_mode = in->st_mode;
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out->st_nlink = in->st_nlink;
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out->st_uid = in->st_uid;
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out->st_gid = in->st_gid;
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out->st_rdev = in->st_rdev;
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out->st_size = in->st_size;
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out->st_blksize = in->st_blksize;
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out->st_blocks = in->st_blocks;
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out->st_atime = in->st_atime;
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out->st_mtime = in->st_mtime;
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out->st_ctime = in->st_ctime;
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out->st_ino = in->st_ino;
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}
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#endif
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uptr internal_stat(const char *path, void *buf) {
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#if SANITIZER_LINUX_USES_64BIT_SYSCALLS
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return internal_syscall(__NR_stat, (uptr)path, (uptr)buf);
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#else
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struct stat64 buf64;
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int res = internal_syscall(__NR_stat64, path, &buf64);
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stat64_to_stat(&buf64, (struct stat *)buf);
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return res;
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#endif
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}
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uptr internal_lstat(const char *path, void *buf) {
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#if SANITIZER_LINUX_USES_64BIT_SYSCALLS
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return internal_syscall(__NR_lstat, (uptr)path, (uptr)buf);
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#else
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struct stat64 buf64;
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int res = internal_syscall(__NR_lstat64, path, &buf64);
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stat64_to_stat(&buf64, (struct stat *)buf);
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return res;
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#endif
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}
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uptr internal_fstat(fd_t fd, void *buf) {
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#if SANITIZER_LINUX_USES_64BIT_SYSCALLS
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return internal_syscall(__NR_fstat, fd, (uptr)buf);
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#else
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struct stat64 buf64;
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int res = internal_syscall(__NR_fstat64, fd, &buf64);
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stat64_to_stat(&buf64, (struct stat *)buf);
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return res;
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#endif
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}
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uptr internal_filesize(fd_t fd) {
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struct stat st;
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if (internal_fstat(fd, &st))
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return -1;
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return (uptr)st.st_size;
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}
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uptr internal_dup2(int oldfd, int newfd) {
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return internal_syscall(__NR_dup2, oldfd, newfd);
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}
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uptr internal_readlink(const char *path, char *buf, uptr bufsize) {
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return internal_syscall(__NR_readlink, (uptr)path, (uptr)buf, bufsize);
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}
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uptr internal_unlink(const char *path) {
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return internal_syscall(__NR_unlink, (uptr)path);
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}
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uptr internal_sched_yield() {
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return internal_syscall(__NR_sched_yield);
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}
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void internal__exit(int exitcode) {
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internal_syscall(__NR_exit_group, exitcode);
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Die(); // Unreachable.
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}
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uptr internal_execve(const char *filename, char *const argv[],
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char *const envp[]) {
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return internal_syscall(__NR_execve, (uptr)filename, (uptr)argv, (uptr)envp);
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}
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// ----------------- sanitizer_common.h
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bool FileExists(const char *filename) {
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struct stat st;
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if (internal_stat(filename, &st))
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return false;
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// Sanity check: filename is a regular file.
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return S_ISREG(st.st_mode);
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}
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uptr GetTid() {
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return internal_syscall(__NR_gettid);
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}
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u64 NanoTime() {
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kernel_timeval tv;
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internal_memset(&tv, 0, sizeof(tv));
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internal_syscall(__NR_gettimeofday, (uptr)&tv, 0);
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return (u64)tv.tv_sec * 1000*1000*1000 + tv.tv_usec * 1000;
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}
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// Like getenv, but reads env directly from /proc and does not use libc.
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// This function should be called first inside __asan_init.
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const char *GetEnv(const char *name) {
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static char *environ;
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static uptr len;
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static bool inited;
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if (!inited) {
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inited = true;
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uptr environ_size;
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len = ReadFileToBuffer("/proc/self/environ",
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&environ, &environ_size, 1 << 26);
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}
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if (!environ || len == 0) return 0;
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uptr namelen = internal_strlen(name);
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const char *p = environ;
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while (*p != '\0') { // will happen at the \0\0 that terminates the buffer
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// proc file has the format NAME=value\0NAME=value\0NAME=value\0...
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const char* endp =
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(char*)internal_memchr(p, '\0', len - (p - environ));
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if (endp == 0) // this entry isn't NUL terminated
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return 0;
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else if (!internal_memcmp(p, name, namelen) && p[namelen] == '=') // Match.
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return p + namelen + 1; // point after =
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p = endp + 1;
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}
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return 0; // Not found.
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}
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extern "C" {
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SANITIZER_WEAK_ATTRIBUTE extern void *__libc_stack_end;
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}
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#if !SANITIZER_GO
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static void ReadNullSepFileToArray(const char *path, char ***arr,
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int arr_size) {
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char *buff;
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uptr buff_size = 0;
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*arr = (char **)MmapOrDie(arr_size * sizeof(char *), "NullSepFileArray");
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ReadFileToBuffer(path, &buff, &buff_size, 1024 * 1024);
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(*arr)[0] = buff;
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int count, i;
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for (count = 1, i = 1; ; i++) {
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if (buff[i] == 0) {
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if (buff[i+1] == 0) break;
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(*arr)[count] = &buff[i+1];
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CHECK_LE(count, arr_size - 1); // FIXME: make this more flexible.
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count++;
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}
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}
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(*arr)[count] = 0;
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}
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#endif
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static void GetArgsAndEnv(char*** argv, char*** envp) {
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#if !SANITIZER_GO
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if (&__libc_stack_end) {
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#endif
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uptr* stack_end = (uptr*)__libc_stack_end;
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int argc = *stack_end;
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*argv = (char**)(stack_end + 1);
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*envp = (char**)(stack_end + argc + 2);
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#if !SANITIZER_GO
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} else {
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static const int kMaxArgv = 2000, kMaxEnvp = 2000;
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ReadNullSepFileToArray("/proc/self/cmdline", argv, kMaxArgv);
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ReadNullSepFileToArray("/proc/self/environ", envp, kMaxEnvp);
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}
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#endif
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}
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void ReExec() {
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char **argv, **envp;
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GetArgsAndEnv(&argv, &envp);
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uptr rv = internal_execve("/proc/self/exe", argv, envp);
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int rverrno;
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CHECK_EQ(internal_iserror(rv, &rverrno), true);
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Printf("execve failed, errno %d\n", rverrno);
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Die();
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}
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void PrepareForSandboxing() {
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// Some kinds of sandboxes may forbid filesystem access, so we won't be able
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// to read the file mappings from /proc/self/maps. Luckily, neither the
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// process will be able to load additional libraries, so it's fine to use the
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// cached mappings.
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MemoryMappingLayout::CacheMemoryMappings();
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// Same for /proc/self/exe in the symbolizer.
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#if !SANITIZER_GO
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if (Symbolizer *sym = Symbolizer::GetOrNull())
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sym->PrepareForSandboxing();
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#endif
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}
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enum MutexState {
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MtxUnlocked = 0,
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MtxLocked = 1,
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MtxSleeping = 2
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};
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BlockingMutex::BlockingMutex(LinkerInitialized) {
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CHECK_EQ(owner_, 0);
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}
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BlockingMutex::BlockingMutex() {
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internal_memset(this, 0, sizeof(*this));
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}
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void BlockingMutex::Lock() {
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atomic_uint32_t *m = reinterpret_cast<atomic_uint32_t *>(&opaque_storage_);
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if (atomic_exchange(m, MtxLocked, memory_order_acquire) == MtxUnlocked)
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return;
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while (atomic_exchange(m, MtxSleeping, memory_order_acquire) != MtxUnlocked)
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internal_syscall(__NR_futex, (uptr)m, FUTEX_WAIT, MtxSleeping, 0, 0, 0);
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}
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void BlockingMutex::Unlock() {
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atomic_uint32_t *m = reinterpret_cast<atomic_uint32_t *>(&opaque_storage_);
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u32 v = atomic_exchange(m, MtxUnlocked, memory_order_relaxed);
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CHECK_NE(v, MtxUnlocked);
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if (v == MtxSleeping)
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internal_syscall(__NR_futex, (uptr)m, FUTEX_WAKE, 1, 0, 0, 0);
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}
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void BlockingMutex::CheckLocked() {
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atomic_uint32_t *m = reinterpret_cast<atomic_uint32_t *>(&opaque_storage_);
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CHECK_NE(MtxUnlocked, atomic_load(m, memory_order_relaxed));
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}
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// ----------------- sanitizer_linux.h
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// The actual size of this structure is specified by d_reclen.
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// Note that getdents64 uses a different structure format. We only provide the
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// 32-bit syscall here.
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struct linux_dirent {
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unsigned long d_ino;
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unsigned long d_off;
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unsigned short d_reclen;
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char d_name[256];
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};
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// Syscall wrappers.
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uptr internal_ptrace(int request, int pid, void *addr, void *data) {
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return internal_syscall(__NR_ptrace, request, pid, (uptr)addr, (uptr)data);
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}
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uptr internal_waitpid(int pid, int *status, int options) {
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return internal_syscall(__NR_wait4, pid, (uptr)status, options,
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0 /* rusage */);
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}
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uptr internal_getpid() {
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return internal_syscall(__NR_getpid);
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}
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uptr internal_getppid() {
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return internal_syscall(__NR_getppid);
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}
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uptr internal_getdents(fd_t fd, struct linux_dirent *dirp, unsigned int count) {
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return internal_syscall(__NR_getdents, fd, (uptr)dirp, count);
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}
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uptr internal_lseek(fd_t fd, OFF_T offset, int whence) {
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return internal_syscall(__NR_lseek, fd, offset, whence);
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}
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uptr internal_prctl(int option, uptr arg2, uptr arg3, uptr arg4, uptr arg5) {
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return internal_syscall(__NR_prctl, option, arg2, arg3, arg4, arg5);
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}
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uptr internal_sigaltstack(const struct sigaltstack *ss,
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struct sigaltstack *oss) {
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return internal_syscall(__NR_sigaltstack, (uptr)ss, (uptr)oss);
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}
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// Doesn't set sa_restorer, use with caution (see below).
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int internal_sigaction_norestorer(int signum, const void *act, void *oldact) {
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__sanitizer_kernel_sigaction_t k_act, k_oldact;
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internal_memset(&k_act, 0, sizeof(__sanitizer_kernel_sigaction_t));
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internal_memset(&k_oldact, 0, sizeof(__sanitizer_kernel_sigaction_t));
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const __sanitizer_sigaction *u_act = (__sanitizer_sigaction *)act;
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__sanitizer_sigaction *u_oldact = (__sanitizer_sigaction *)oldact;
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if (u_act) {
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k_act.handler = u_act->handler;
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k_act.sigaction = u_act->sigaction;
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internal_memcpy(&k_act.sa_mask, &u_act->sa_mask,
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sizeof(__sanitizer_kernel_sigset_t));
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k_act.sa_flags = u_act->sa_flags;
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// FIXME: most often sa_restorer is unset, however the kernel requires it
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// to point to a valid signal restorer that calls the rt_sigreturn syscall.
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// If sa_restorer passed to the kernel is NULL, the program may crash upon
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// signal delivery or fail to unwind the stack in the signal handler.
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// libc implementation of sigaction() passes its own restorer to
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// rt_sigaction, so we need to do the same (we'll need to reimplement the
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// restorers; for x86_64 the restorer address can be obtained from
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// oldact->sa_restorer upon a call to sigaction(xxx, NULL, oldact).
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k_act.sa_restorer = u_act->sa_restorer;
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}
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uptr result = internal_syscall(__NR_rt_sigaction, (uptr)signum,
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(uptr)(u_act ? &k_act : NULL),
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(uptr)(u_oldact ? &k_oldact : NULL),
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(uptr)sizeof(__sanitizer_kernel_sigset_t));
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if ((result == 0) && u_oldact) {
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u_oldact->handler = k_oldact.handler;
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u_oldact->sigaction = k_oldact.sigaction;
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internal_memcpy(&u_oldact->sa_mask, &k_oldact.sa_mask,
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sizeof(__sanitizer_kernel_sigset_t));
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u_oldact->sa_flags = k_oldact.sa_flags;
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u_oldact->sa_restorer = k_oldact.sa_restorer;
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}
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return result;
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}
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uptr internal_sigprocmask(int how, __sanitizer_sigset_t *set,
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__sanitizer_sigset_t *oldset) {
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__sanitizer_kernel_sigset_t *k_set = (__sanitizer_kernel_sigset_t *)set;
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__sanitizer_kernel_sigset_t *k_oldset = (__sanitizer_kernel_sigset_t *)oldset;
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return internal_syscall(__NR_rt_sigprocmask, (uptr)how, &k_set->sig[0],
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&k_oldset->sig[0], sizeof(__sanitizer_kernel_sigset_t));
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}
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void internal_sigfillset(__sanitizer_sigset_t *set) {
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internal_memset(set, 0xff, sizeof(*set));
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}
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void internal_sigdelset(__sanitizer_sigset_t *set, int signum) {
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signum -= 1;
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CHECK_GE(signum, 0);
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CHECK_LT(signum, sizeof(*set) * 8);
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__sanitizer_kernel_sigset_t *k_set = (__sanitizer_kernel_sigset_t *)set;
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|
const uptr idx = signum / (sizeof(k_set->sig[0]) * 8);
|
|
const uptr bit = signum % (sizeof(k_set->sig[0]) * 8);
|
|
k_set->sig[idx] &= ~(1 << bit);
|
|
}
|
|
|
|
// ThreadLister implementation.
|
|
ThreadLister::ThreadLister(int pid)
|
|
: pid_(pid),
|
|
descriptor_(-1),
|
|
buffer_(4096),
|
|
error_(true),
|
|
entry_((struct linux_dirent *)buffer_.data()),
|
|
bytes_read_(0) {
|
|
char task_directory_path[80];
|
|
internal_snprintf(task_directory_path, sizeof(task_directory_path),
|
|
"/proc/%d/task/", pid);
|
|
uptr openrv = internal_open(task_directory_path, O_RDONLY | O_DIRECTORY);
|
|
if (internal_iserror(openrv)) {
|
|
error_ = true;
|
|
Report("Can't open /proc/%d/task for reading.\n", pid);
|
|
} else {
|
|
error_ = false;
|
|
descriptor_ = openrv;
|
|
}
|
|
}
|
|
|
|
int ThreadLister::GetNextTID() {
|
|
int tid = -1;
|
|
do {
|
|
if (error_)
|
|
return -1;
|
|
if ((char *)entry_ >= &buffer_[bytes_read_] && !GetDirectoryEntries())
|
|
return -1;
|
|
if (entry_->d_ino != 0 && entry_->d_name[0] >= '0' &&
|
|
entry_->d_name[0] <= '9') {
|
|
// Found a valid tid.
|
|
tid = (int)internal_atoll(entry_->d_name);
|
|
}
|
|
entry_ = (struct linux_dirent *)(((char *)entry_) + entry_->d_reclen);
|
|
} while (tid < 0);
|
|
return tid;
|
|
}
|
|
|
|
void ThreadLister::Reset() {
|
|
if (error_ || descriptor_ < 0)
|
|
return;
|
|
internal_lseek(descriptor_, 0, SEEK_SET);
|
|
}
|
|
|
|
ThreadLister::~ThreadLister() {
|
|
if (descriptor_ >= 0)
|
|
internal_close(descriptor_);
|
|
}
|
|
|
|
bool ThreadLister::error() { return error_; }
|
|
|
|
bool ThreadLister::GetDirectoryEntries() {
|
|
CHECK_GE(descriptor_, 0);
|
|
CHECK_NE(error_, true);
|
|
bytes_read_ = internal_getdents(descriptor_,
|
|
(struct linux_dirent *)buffer_.data(),
|
|
buffer_.size());
|
|
if (internal_iserror(bytes_read_)) {
|
|
Report("Can't read directory entries from /proc/%d/task.\n", pid_);
|
|
error_ = true;
|
|
return false;
|
|
} else if (bytes_read_ == 0) {
|
|
return false;
|
|
}
|
|
entry_ = (struct linux_dirent *)buffer_.data();
|
|
return true;
|
|
}
|
|
|
|
uptr GetPageSize() {
|
|
#if defined(__x86_64__) || defined(__i386__)
|
|
return EXEC_PAGESIZE;
|
|
#else
|
|
return sysconf(_SC_PAGESIZE); // EXEC_PAGESIZE may not be trustworthy.
|
|
#endif
|
|
}
|
|
|
|
static char proc_self_exe_cache_str[kMaxPathLength];
|
|
static uptr proc_self_exe_cache_len = 0;
|
|
|
|
uptr ReadBinaryName(/*out*/char *buf, uptr buf_len) {
|
|
uptr module_name_len = internal_readlink(
|
|
"/proc/self/exe", buf, buf_len);
|
|
int readlink_error;
|
|
if (internal_iserror(module_name_len, &readlink_error)) {
|
|
if (proc_self_exe_cache_len) {
|
|
// If available, use the cached module name.
|
|
CHECK_LE(proc_self_exe_cache_len, buf_len);
|
|
internal_strncpy(buf, proc_self_exe_cache_str, buf_len);
|
|
module_name_len = internal_strlen(proc_self_exe_cache_str);
|
|
} else {
|
|
// We can't read /proc/self/exe for some reason, assume the name of the
|
|
// binary is unknown.
|
|
Report("WARNING: readlink(\"/proc/self/exe\") failed with errno %d, "
|
|
"some stack frames may not be symbolized\n", readlink_error);
|
|
module_name_len = internal_snprintf(buf, buf_len, "/proc/self/exe");
|
|
}
|
|
CHECK_LT(module_name_len, buf_len);
|
|
buf[module_name_len] = '\0';
|
|
}
|
|
return module_name_len;
|
|
}
|
|
|
|
void CacheBinaryName() {
|
|
if (!proc_self_exe_cache_len) {
|
|
proc_self_exe_cache_len =
|
|
ReadBinaryName(proc_self_exe_cache_str, kMaxPathLength);
|
|
}
|
|
}
|
|
|
|
// Match full names of the form /path/to/base_name{-,.}*
|
|
bool LibraryNameIs(const char *full_name, const char *base_name) {
|
|
const char *name = full_name;
|
|
// Strip path.
|
|
while (*name != '\0') name++;
|
|
while (name > full_name && *name != '/') name--;
|
|
if (*name == '/') name++;
|
|
uptr base_name_length = internal_strlen(base_name);
|
|
if (internal_strncmp(name, base_name, base_name_length)) return false;
|
|
return (name[base_name_length] == '-' || name[base_name_length] == '.');
|
|
}
|
|
|
|
#if !SANITIZER_ANDROID
|
|
// Call cb for each region mapped by map.
|
|
void ForEachMappedRegion(link_map *map, void (*cb)(const void *, uptr)) {
|
|
typedef ElfW(Phdr) Elf_Phdr;
|
|
typedef ElfW(Ehdr) Elf_Ehdr;
|
|
char *base = (char *)map->l_addr;
|
|
Elf_Ehdr *ehdr = (Elf_Ehdr *)base;
|
|
char *phdrs = base + ehdr->e_phoff;
|
|
char *phdrs_end = phdrs + ehdr->e_phnum * ehdr->e_phentsize;
|
|
|
|
// Find the segment with the minimum base so we can "relocate" the p_vaddr
|
|
// fields. Typically ET_DYN objects (DSOs) have base of zero and ET_EXEC
|
|
// objects have a non-zero base.
|
|
uptr preferred_base = (uptr)-1;
|
|
for (char *iter = phdrs; iter != phdrs_end; iter += ehdr->e_phentsize) {
|
|
Elf_Phdr *phdr = (Elf_Phdr *)iter;
|
|
if (phdr->p_type == PT_LOAD && preferred_base > (uptr)phdr->p_vaddr)
|
|
preferred_base = (uptr)phdr->p_vaddr;
|
|
}
|
|
|
|
// Compute the delta from the real base to get a relocation delta.
|
|
sptr delta = (uptr)base - preferred_base;
|
|
// Now we can figure out what the loader really mapped.
|
|
for (char *iter = phdrs; iter != phdrs_end; iter += ehdr->e_phentsize) {
|
|
Elf_Phdr *phdr = (Elf_Phdr *)iter;
|
|
if (phdr->p_type == PT_LOAD) {
|
|
uptr seg_start = phdr->p_vaddr + delta;
|
|
uptr seg_end = seg_start + phdr->p_memsz;
|
|
// None of these values are aligned. We consider the ragged edges of the
|
|
// load command as defined, since they are mapped from the file.
|
|
seg_start = RoundDownTo(seg_start, GetPageSizeCached());
|
|
seg_end = RoundUpTo(seg_end, GetPageSizeCached());
|
|
cb((void *)seg_start, seg_end - seg_start);
|
|
}
|
|
}
|
|
}
|
|
#endif
|
|
|
|
#if defined(__x86_64__)
|
|
// We cannot use glibc's clone wrapper, because it messes with the child
|
|
// task's TLS. It writes the PID and TID of the child task to its thread
|
|
// descriptor, but in our case the child task shares the thread descriptor with
|
|
// the parent (because we don't know how to allocate a new thread
|
|
// descriptor to keep glibc happy). So the stock version of clone(), when
|
|
// used with CLONE_VM, would end up corrupting the parent's thread descriptor.
|
|
uptr internal_clone(int (*fn)(void *), void *child_stack, int flags, void *arg,
|
|
int *parent_tidptr, void *newtls, int *child_tidptr) {
|
|
long long res;
|
|
if (!fn || !child_stack)
|
|
return -EINVAL;
|
|
CHECK_EQ(0, (uptr)child_stack % 16);
|
|
child_stack = (char *)child_stack - 2 * sizeof(unsigned long long);
|
|
((unsigned long long *)child_stack)[0] = (uptr)fn;
|
|
((unsigned long long *)child_stack)[1] = (uptr)arg;
|
|
register void *r8 __asm__("r8") = newtls;
|
|
register int *r10 __asm__("r10") = child_tidptr;
|
|
__asm__ __volatile__(
|
|
/* %rax = syscall(%rax = __NR_clone,
|
|
* %rdi = flags,
|
|
* %rsi = child_stack,
|
|
* %rdx = parent_tidptr,
|
|
* %r8 = new_tls,
|
|
* %r10 = child_tidptr)
|
|
*/
|
|
"syscall\n"
|
|
|
|
/* if (%rax != 0)
|
|
* return;
|
|
*/
|
|
"testq %%rax,%%rax\n"
|
|
"jnz 1f\n"
|
|
|
|
/* In the child. Terminate unwind chain. */
|
|
// XXX: We should also terminate the CFI unwind chain
|
|
// here. Unfortunately clang 3.2 doesn't support the
|
|
// necessary CFI directives, so we skip that part.
|
|
"xorq %%rbp,%%rbp\n"
|
|
|
|
/* Call "fn(arg)". */
|
|
"popq %%rax\n"
|
|
"popq %%rdi\n"
|
|
"call *%%rax\n"
|
|
|
|
/* Call _exit(%rax). */
|
|
"movq %%rax,%%rdi\n"
|
|
"movq %2,%%rax\n"
|
|
"syscall\n"
|
|
|
|
/* Return to parent. */
|
|
"1:\n"
|
|
: "=a" (res)
|
|
: "a"(__NR_clone), "i"(__NR_exit),
|
|
"S"(child_stack),
|
|
"D"(flags),
|
|
"d"(parent_tidptr),
|
|
"r"(r8),
|
|
"r"(r10)
|
|
: "rsp", "memory", "r11", "rcx");
|
|
return res;
|
|
}
|
|
#endif // defined(__x86_64__)
|
|
|
|
#if SANITIZER_ANDROID
|
|
// This thing is not, strictly speaking, async signal safe, but it does not seem
|
|
// to cause any issues. Alternative is writing to log devices directly, but
|
|
// their location and message format might change in the future, so we'd really
|
|
// like to avoid that.
|
|
void AndroidLogWrite(const char *buffer) {
|
|
__android_log_write(ANDROID_LOG_INFO, NULL, buffer);
|
|
}
|
|
#endif
|
|
|
|
bool IsDeadlySignal(int signum) {
|
|
return (signum == SIGSEGV) && common_flags()->handle_segv;
|
|
}
|
|
|
|
} // namespace __sanitizer
|
|
|
|
#endif // SANITIZER_LINUX
|