1 /*
2 * Copyright (C) 2008 The Android Open Source Project
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * * Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * * Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in
12 * the documentation and/or other materials provided with the
13 * distribution.
14 *
15 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
16 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
17 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
18 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
19 * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
20 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
21 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
22 * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
23 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
24 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
25 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26 * SUCH DAMAGE.
27 */
28
29 #undef _FORTIFY_SOURCE
30
31 #include <errno.h>
32 #include <fcntl.h>
33 #include <stdarg.h>
34 #include <sys/resource.h>
35 #include <sys/types.h>
36 #include <sys/uio.h>
37 #include <sys/vfs.h>
38 #include <unistd.h>
39
40 #include "private/bionic_fdtrack.h"
41
42 #if defined(__LP64__)
43 #error This code is only needed on 32-bit systems!
44 #endif
45
46 // System calls we need.
47 extern "C" int __llseek(int, unsigned long, unsigned long, off64_t*, int);
48
49 // For lseek64 we need to use the llseek system call which splits the off64_t in two and
50 // returns the off64_t result via a pointer because 32-bit kernels can't return 64-bit results.
lseek64(int fd,off64_t off,int whence)51 off64_t lseek64(int fd, off64_t off, int whence) {
52 off64_t result;
53 unsigned long off_hi = static_cast<unsigned long>(off >> 32);
54 unsigned long off_lo = static_cast<unsigned long>(off);
55 if (__llseek(fd, off_hi, off_lo, &result, whence) < 0) {
56 return -1;
57 }
58 return result;
59 }
60
61 // There is no pread for 32-bit off_t, so we need to widen and call pread64.
pread(int fd,void * buf,size_t byte_count,off_t offset)62 ssize_t pread(int fd, void* buf, size_t byte_count, off_t offset) {
63 return pread64(fd, buf, byte_count, static_cast<off64_t>(offset));
64 }
65
66 // There is no pwrite for 32-bit off_t, so we need to widen and call pwrite64.
pwrite(int fd,const void * buf,size_t byte_count,off_t offset)67 ssize_t pwrite(int fd, const void* buf, size_t byte_count, off_t offset) {
68 return pwrite64(fd, buf, byte_count, static_cast<off64_t>(offset));
69 }
70
71 // There is no fallocate for 32-bit off_t, so we need to widen and call fallocate64.
fallocate(int fd,int mode,off_t offset,off_t length)72 int fallocate(int fd, int mode, off_t offset, off_t length) {
73 return fallocate64(fd, mode, static_cast<off64_t>(offset), static_cast<off64_t>(length));
74 }
75
76 // There is no getrlimit64 system call, so we need to use prlimit64.
getrlimit64(int resource,rlimit64 * limits64)77 int getrlimit64(int resource, rlimit64* limits64) {
78 return prlimit64(0, resource, nullptr, limits64);
79 }
80
81 // There is no setrlimit64 system call, so we need to use prlimit64.
setrlimit64(int resource,const rlimit64 * limits64)82 int setrlimit64(int resource, const rlimit64* limits64) {
83 return prlimit64(0, resource, limits64, nullptr);
84 }
85
86 // There is no prlimit system call, so we need to use prlimit64.
prlimit(pid_t pid,int resource,const rlimit * n32,rlimit * o32)87 int prlimit(pid_t pid, int resource, const rlimit* n32, rlimit* o32) {
88 rlimit64 n64;
89 if (n32 != nullptr) {
90 n64.rlim_cur = (n32->rlim_cur == RLIM_INFINITY) ? RLIM64_INFINITY : n32->rlim_cur;
91 n64.rlim_max = (n32->rlim_max == RLIM_INFINITY) ? RLIM64_INFINITY : n32->rlim_max;
92 }
93
94 rlimit64 o64;
95 int result = prlimit64(pid, resource,
96 (n32 != nullptr) ? &n64 : nullptr,
97 (o32 != nullptr) ? &o64 : nullptr);
98 if (result != -1 && o32 != nullptr) {
99 o32->rlim_cur = (o64.rlim_cur == RLIM64_INFINITY) ? RLIM_INFINITY : o64.rlim_cur;
100 o32->rlim_max = (o64.rlim_max == RLIM64_INFINITY) ? RLIM_INFINITY : o64.rlim_max;
101 }
102 return result;
103 }
104