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/*
* 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/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);
// 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));
}
// 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;
}
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