mirror of
https://github.com/jart/cosmopolitan.git
synced 2025-02-07 15:03:34 +00:00
6ffed14b9c
Actually Portable Executable now supports Android. Cosmo's old mmap code required a 47 bit address space. The new implementation is very agnostic and supports both smaller address spaces (e.g. embedded) and even modern 56-bit PML5T paging for x86 which finally came true on Zen4 Threadripper Cosmopolitan no longer requires UNIX systems to observe the Windows 64kb granularity; i.e. sysconf(_SC_PAGE_SIZE) will now report the host native page size. This fixes a longstanding POSIX conformance issue, concerning file mappings that overlap the end of file. Other aspects of conformance have been improved too, such as the subtleties of address assignment and and the various subtleties surrounding MAP_FIXED and MAP_FIXED_NOREPLACE On Windows, mappings larger than 100 megabytes won't be broken down into thousands of independent 64kb mappings. Support for MAP_STACK is removed by this change; please use NewCosmoStack() instead. Stack overflow avoidance is now being implemented using the POSIX thread APIs. Please use GetStackBottom() and GetStackAddr(), instead of the old error-prone GetStackAddr() and HaveStackMemory() APIs which are removed.
98 lines
4.3 KiB
C
98 lines
4.3 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/sysv/consts/msync.h"
|
|
#include "libc/assert.h"
|
|
#include "libc/calls/calls.h"
|
|
#include "libc/calls/cp.internal.h"
|
|
#include "libc/calls/syscall-nt.internal.h"
|
|
#include "libc/calls/syscall-sysv.internal.h"
|
|
#include "libc/dce.h"
|
|
#include "libc/intrin/strace.internal.h"
|
|
#include "libc/macros.internal.h"
|
|
#include "libc/sysv/errfuns.h"
|
|
|
|
/**
|
|
* Synchronize memory mapping changes to disk.
|
|
*
|
|
* Without this, there's no guarantee memory is written back to disk.
|
|
* Particularly on RHEL5, OpenBSD, and Windows NT.
|
|
*
|
|
* @param addr needs to be 4096-byte page aligned
|
|
* @param flags needs MS_ASYNC or MS_SYNC and can have MS_INVALIDATE
|
|
* @return 0 on success or -1 w/ errno
|
|
* @raise ECANCELED if thread was cancelled in masked mode
|
|
* @raise EINTR if we needed to block and a signal was delivered instead
|
|
* @raise EINVAL if `MS_SYNC` and `MS_ASYNC` were both specified
|
|
* @raise EINVAL if unknown `flags` were passed
|
|
* @cancelationpoint
|
|
*/
|
|
int msync(void *addr, size_t size, int flags) {
|
|
int rc;
|
|
|
|
if ((flags & ~(MS_SYNC | MS_ASYNC | MS_INVALIDATE)) ||
|
|
(flags & (MS_SYNC | MS_ASYNC)) == (MS_SYNC | MS_ASYNC)) {
|
|
rc = einval();
|
|
goto Finished;
|
|
}
|
|
|
|
// According to POSIX, either MS_SYNC or MS_ASYNC must be specified
|
|
// in flags, and indeed failure to include one of these flags will
|
|
// cause msync() to fail on some systems. However, Linux permits a
|
|
// call to msync() that specifies neither of these flags, with
|
|
// semantics that are (currently) equivalent to specifying MS_ASYNC.
|
|
// ──Quoth msync(2) of Linux Programmer's Manual
|
|
int sysflags = flags;
|
|
sysflags = flags;
|
|
if (flags & MS_ASYNC) {
|
|
sysflags = MS_ASYNC;
|
|
} else if (flags & MS_SYNC) {
|
|
sysflags = MS_SYNC;
|
|
} else {
|
|
sysflags = MS_ASYNC;
|
|
}
|
|
if (flags & MS_INVALIDATE) {
|
|
sysflags |= MS_INVALIDATE;
|
|
}
|
|
|
|
// FreeBSD's manual says "The flags argument was both MS_ASYNC and
|
|
// MS_INVALIDATE. Only one of these flags is allowed." which makes
|
|
// following the POSIX recommendation somewhat difficult.
|
|
if (IsFreebsd()) {
|
|
if (sysflags == (MS_ASYNC | MS_INVALIDATE)) {
|
|
sysflags = MS_INVALIDATE;
|
|
}
|
|
}
|
|
|
|
// FreeBSD specifies MS_SYNC as 0 so we shift the Cosmo constants
|
|
if (IsFreebsd()) {
|
|
sysflags >>= 1;
|
|
}
|
|
|
|
BEGIN_CANCELATION_POINT;
|
|
if (!IsWindows()) {
|
|
rc = sys_msync(addr, size, sysflags);
|
|
} else {
|
|
rc = sys_msync_nt(addr, size, sysflags);
|
|
}
|
|
END_CANCELATION_POINT;
|
|
|
|
Finished:
|
|
STRACE("msync(%p, %'zu, %#x) → %d% m", addr, size, flags, rc);
|
|
return rc;
|
|
}
|