mirror of
https://github.com/jart/cosmopolitan.git
synced 2025-01-31 03:27:39 +00:00
69 lines
3.5 KiB
C
69 lines
3.5 KiB
C
/*-*- mode:c;indent-tabs-mode:nil;c-basic-offset:2;tab-width:8;coding:utf-8 -*-│
|
|
│ vi: set et ft=c ts=2 sts=2 sw=2 fenc=utf-8 :vi │
|
|
╞══════════════════════════════════════════════════════════════════════════════╡
|
|
│ Copyright 2020 Justine Alexandra Roberts Tunney │
|
|
│ │
|
|
│ Permission to use, copy, modify, and/or distribute this software for │
|
|
│ any purpose with or without fee is hereby granted, provided that the │
|
|
│ above copyright notice and this permission notice appear in all copies. │
|
|
│ │
|
|
│ THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL │
|
|
│ WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED │
|
|
│ WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE │
|
|
│ AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL │
|
|
│ DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR │
|
|
│ PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER │
|
|
│ TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR │
|
|
│ PERFORMANCE OF THIS SOFTWARE. │
|
|
╚─────────────────────────────────────────────────────────────────────────────*/
|
|
#include "libc/calls/calls.h"
|
|
#include "libc/calls/syscall-nt.internal.h"
|
|
#include "libc/calls/syscall-sysv.internal.h"
|
|
#include "libc/dce.h"
|
|
#include "libc/intrin/strace.h"
|
|
#include "libc/runtime/runtime.h"
|
|
#include "libc/sysv/errfuns.h"
|
|
|
|
static int __madvise(void *addr, size_t length, int advice) {
|
|
|
|
// simulate linux behavior of validating alignment
|
|
if ((uintptr_t)addr & (__pagesize - 1))
|
|
return einval();
|
|
|
|
// simulate linux behavior of checking for negative length
|
|
if ((ssize_t)length < 0)
|
|
return einval();
|
|
|
|
// madvise(0, 0, advice) may be used to validate advice
|
|
if (!length && (IsFreebsd() || IsNetbsd()))
|
|
addr = (void *)65536l;
|
|
|
|
if (!IsWindows())
|
|
return sys_madvise(addr, length, advice);
|
|
return sys_madvise_nt(addr, length, advice);
|
|
}
|
|
|
|
/**
|
|
* Declares intent to OS on how memory region will be used.
|
|
*
|
|
* `madvise(0, 0, advice)` is recommended for validating `advise` and it
|
|
* will always be the case that a `length` of zero is a no-op otherwise.
|
|
*
|
|
* Having the interval overlap unmapped pages has undefined behavior. On
|
|
* Linux, this can be counted upon to raise ENOMEM. Other OSes vary much
|
|
* in behavior here; they'll might ignore unmapped regions or they might
|
|
* raise EINVAL, EFAULT, or ENOMEM.
|
|
*
|
|
* @param advice can be MADV_WILLNEED, MADV_SEQUENTIAL, MADV_FREE, etc.
|
|
* @return 0 on success, or -1 w/ errno
|
|
* @raise EINVAL if `advice` isn't valid or supported by system
|
|
* @raise EINVAL if `addr` isn't getpagesize() aligned
|
|
* @raise EINVAL if `length` is negative
|
|
* @see libc/sysv/consts.sh
|
|
* @see fadvise()
|
|
*/
|
|
int madvise(void *addr, size_t length, int advice) {
|
|
int rc = __madvise(addr, length, advice);
|
|
STRACE("madvise(%p, %'zu, %d) → %d% m", addr, length, advice, rc);
|
|
return rc;
|
|
}
|