| /* |
| * Copyright (C) 2008 The Android Open Source Project |
| * All rights reserved. |
| * |
| * Redistribution and use in source and binary forms, with or without |
| * modification, are permitted provided that the following conditions |
| * are met: |
| * * Redistributions of source code must retain the above copyright |
| * notice, this list of conditions and the following disclaimer. |
| * * Redistributions in binary form must reproduce the above copyright |
| * notice, this list of conditions and the following disclaimer in |
| * the documentation and/or other materials provided with the |
| * distribution. |
| * |
| * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS |
| * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT |
| * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS |
| * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE |
| * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, |
| * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, |
| * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS |
| * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED |
| * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, |
| * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT |
| * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF |
| * SUCH DAMAGE. |
| */ |
| |
| #undef _FORTIFY_SOURCE |
| |
| #include <errno.h> |
| #include <fcntl.h> |
| #include <stdarg.h> |
| #include <sys/resource.h> |
| #include <sys/types.h> |
| #include <sys/uio.h> |
| #include <sys/vfs.h> |
| #include <unistd.h> |
| |
| #if __LP64__ |
| #error This code is only needed on 32-bit systems! |
| #endif |
| |
| // System calls we need. |
| extern "C" int __fcntl64(int, int, void*); |
| extern "C" int __llseek(int, unsigned long, unsigned long, off64_t*, int); |
| extern "C" int __preadv64(int, const struct iovec*, int, long, long); |
| extern "C" int __pwritev64(int, const struct iovec*, int, long, long); |
| |
| // For fcntl we use the fcntl64 system call to signal that we're using struct flock64. |
| int fcntl(int fd, int cmd, ...) { |
| va_list ap; |
| |
| va_start(ap, cmd); |
| void* arg = va_arg(ap, void*); |
| va_end(ap); |
| |
| return __fcntl64(fd, cmd, arg); |
| } |
| |
| // For lseek64 we need to use the llseek system call which splits the off64_t in two and |
| // returns the off64_t result via a pointer because 32-bit kernels can't return 64-bit results. |
| off64_t lseek64(int fd, off64_t off, int whence) { |
| off64_t result; |
| unsigned long off_hi = static_cast<unsigned long>(off >> 32); |
| unsigned long off_lo = static_cast<unsigned long>(off); |
| if (__llseek(fd, off_hi, off_lo, &result, whence) < 0) { |
| return -1; |
| } |
| return result; |
| } |
| |
| // There is no pread for 32-bit off_t, so we need to widen and call pread64. |
| ssize_t pread(int fd, void* buf, size_t byte_count, off_t offset) { |
| return pread64(fd, buf, byte_count, static_cast<off64_t>(offset)); |
| } |
| |
| // There is no pwrite for 32-bit off_t, so we need to widen and call pwrite64. |
| ssize_t pwrite(int fd, const void* buf, size_t byte_count, off_t offset) { |
| return pwrite64(fd, buf, byte_count, static_cast<off64_t>(offset)); |
| } |
| |
| // On LP32, there is no off_t preadv/pwritev, and even the 64-bit preadv/pwritev |
| // don't use off64_t (see SYSCALLS.TXT for more). Here, this means that we need |
| // to implement all four functions because the two system calls don't match any |
| // of the userspace functions. Unlike llseek, the pair is split lo-hi, not hi-lo. |
| ssize_t preadv(int fd, const struct iovec* ios, int count, off_t offset) { |
| return __preadv64(fd, ios, count, offset, 0); |
| } |
| ssize_t preadv64(int fd, const struct iovec* ios, int count, off64_t offset) { |
| return __preadv64(fd, ios, count, offset, offset >> 32); |
| } |
| ssize_t pwritev(int fd, const struct iovec* ios, int count, off_t offset) { |
| return __pwritev64(fd, ios, count, offset, 0); |
| } |
| ssize_t pwritev64(int fd, const struct iovec* ios, int count, off64_t offset) { |
| return __pwritev64(fd, ios, count, offset, offset >> 32); |
| } |
| |
| // There is no fallocate for 32-bit off_t, so we need to widen and call fallocate64. |
| int fallocate(int fd, int mode, off_t offset, off_t length) { |
| return fallocate64(fd, mode, static_cast<off64_t>(offset), static_cast<off64_t>(length)); |
| } |
| |
| // There is no getrlimit64 system call, so we need to use prlimit64. |
| int getrlimit64(int resource, rlimit64* limits64) { |
| return prlimit64(0, resource, NULL, limits64); |
| } |
| |
| // There is no setrlimit64 system call, so we need to use prlimit64. |
| int setrlimit64(int resource, const rlimit64* limits64) { |
| return prlimit64(0, resource, limits64, NULL); |
| } |
| |
| // There is no prlimit system call, so we need to use prlimit64. |
| int prlimit(pid_t pid, int resource, const rlimit* n32, rlimit* o32) { |
| rlimit64 n64; |
| if (n32 != nullptr) { |
| n64.rlim_cur = (n32->rlim_cur == RLIM_INFINITY) ? RLIM64_INFINITY : n32->rlim_cur; |
| n64.rlim_max = (n32->rlim_max == RLIM_INFINITY) ? RLIM64_INFINITY : n32->rlim_max; |
| } |
| |
| rlimit64 o64; |
| int result = prlimit64(pid, resource, |
| (n32 != nullptr) ? &n64 : nullptr, |
| (o32 != nullptr) ? &o64 : nullptr); |
| if (result != -1 && o32 != nullptr) { |
| o32->rlim_cur = (o64.rlim_cur == RLIM64_INFINITY) ? RLIM_INFINITY : o64.rlim_cur; |
| o32->rlim_max = (o64.rlim_max == RLIM64_INFINITY) ? RLIM_INFINITY : o64.rlim_max; |
| } |
| return result; |
| } |