mirror of
git://git.sv.gnu.org/emacs.git
synced 2025-12-18 20:00:36 -08:00
265 lines
8 KiB
C
265 lines
8 KiB
C
/* vmix.c: VIRTUAL MEMORY MAPPING FOR UNIX (ISH)
|
|
*
|
|
* $Id$
|
|
* Copyright (c) 2001-2014 Ravenbrook Limited. See end of file for license.
|
|
*
|
|
* .purpose: This is the implementation of the virtual memory mapping
|
|
* interface (vm.h) for Unix-like operating systems. It was created
|
|
* by copying vmfr.c (the FreeBSD) implementation (as that seemed to
|
|
* use the most standards conforming interfaces). vmfr.c was itself
|
|
* copied from vli.c (Linux) which was itself copied from vmo1.c (OSF/1
|
|
* / DIGITAL UNIX / Tru64).
|
|
*
|
|
* .deployed: Currently used on Darwin (OS X) and FreeBSD.
|
|
*
|
|
* .design: See <design/vm/>. .design.mmap: mmap(2) is used to
|
|
* reserve address space by creating a mapping with page access none.
|
|
* mmap(2) is used to map pages onto store by creating a copy-on-write
|
|
* (MAP_PRIVATE) mapping with the flag MAP_ANON.
|
|
*
|
|
* .non-standard: Note that the MAP_ANON flag is non-standard; it is
|
|
* available on Darwin and FreeBSD. .non-standard.linux: Linux seems
|
|
* to use MAP_ANONYMOUS instead. Some Linux systems make MAP_ANON
|
|
* available and deprecate it. .non-standard.sesame: On Linux getting
|
|
* a definition of MAP_ANON requires a _BSD_SOURCE to be defined prior
|
|
* to <sys/mman.h>; see config.h.
|
|
*
|
|
* .assume.not-last: The implementation of VMInit assumes that
|
|
* mmap() will not choose a region which contains the last page
|
|
* in the address space, so that the limit of the mapped area
|
|
* is representable.
|
|
*
|
|
* .assume.mmap.err: ENOMEM is the only error we really expect to
|
|
* get from mmap. The others are either caused by invalid params
|
|
* or features we don't use. See mmap(2) for details.
|
|
*
|
|
* .remap: Possibly this should use mremap to reduce the number of
|
|
* distinct mappings. According to our current testing, it doesn't
|
|
* seem to be a problem.
|
|
*/
|
|
|
|
#include "mpm.h"
|
|
#include "vm.h"
|
|
|
|
/* for mmap(2), munmap(2) */
|
|
#include <sys/types.h>
|
|
#include <sys/mman.h> /* see .feature.li in config.h */
|
|
|
|
/* for errno(2) */
|
|
#include <errno.h>
|
|
|
|
/* for getpagesize(3) */
|
|
#include <unistd.h>
|
|
|
|
|
|
#if !defined(MPS_OS_FR) && !defined(MPS_OS_XC) && !defined(MPS_OS_LI)
|
|
#error "vmix.c is Unix-like specific, currently MPS_OS_FR XC LI"
|
|
#endif
|
|
|
|
SRCID(vmix, "$Id$");
|
|
|
|
|
|
/* PageSize -- return operating system page size */
|
|
|
|
Size PageSize(void)
|
|
{
|
|
int pageSize;
|
|
|
|
/* Find out the operating system page size */
|
|
pageSize = getpagesize();
|
|
|
|
/* Check the page size will fit in a Size. */
|
|
AVER((unsigned long)pageSize <= (unsigned long)(Size)-1);
|
|
|
|
return (Size)pageSize;
|
|
}
|
|
|
|
|
|
Res VMParamFromArgs(void *params, size_t paramSize, ArgList args)
|
|
{
|
|
AVER(params != NULL);
|
|
AVERT(ArgList, args);
|
|
UNUSED(paramSize);
|
|
return ResOK;
|
|
}
|
|
|
|
|
|
/* VMInit -- reserve some virtual address space, and create a VM structure */
|
|
|
|
Res VMInit(VM vm, Size size, Size grainSize, void *params)
|
|
{
|
|
Size pageSize, reserved;
|
|
void *vbase;
|
|
|
|
AVER(vm != NULL);
|
|
AVERT(ArenaGrainSize, grainSize);
|
|
AVER(size > 0);
|
|
AVER(params != NULL);
|
|
|
|
pageSize = PageSize();
|
|
|
|
/* Grains must consist of whole pages. */
|
|
AVER(grainSize % pageSize == 0);
|
|
|
|
/* Check that the rounded-up sizes will fit in a Size. */
|
|
size = SizeRoundUp(size, grainSize);
|
|
if (size < grainSize || size > (Size)(size_t)-1)
|
|
return ResRESOURCE;
|
|
reserved = size + grainSize - pageSize;
|
|
if (reserved < grainSize || reserved > (Size)(size_t)-1)
|
|
return ResRESOURCE;
|
|
|
|
/* See .assume.not-last. */
|
|
vbase = mmap(0, reserved,
|
|
PROT_NONE, MAP_ANON | MAP_PRIVATE,
|
|
-1, 0);
|
|
/* On Darwin the MAP_FAILED return value is not documented, but does
|
|
* work. MAP_FAILED _is_ documented by POSIX.
|
|
*/
|
|
if (vbase == MAP_FAILED) {
|
|
int e = errno;
|
|
AVER(e == ENOMEM); /* .assume.mmap.err */
|
|
return ResRESOURCE;
|
|
}
|
|
|
|
vm->pageSize = pageSize;
|
|
vm->block = vbase;
|
|
vm->base = AddrAlignUp(vbase, grainSize);
|
|
vm->limit = AddrAdd(vm->base, size);
|
|
AVER(vm->base < vm->limit); /* .assume.not-last */
|
|
AVER(vm->limit <= AddrAdd((Addr)vm->block, reserved));
|
|
vm->reserved = reserved;
|
|
vm->mapped = 0;
|
|
|
|
vm->sig = VMSig;
|
|
AVERT(VM, vm);
|
|
|
|
EVENT3(VMInit, vm, VMBase(vm), VMLimit(vm));
|
|
return ResOK;
|
|
}
|
|
|
|
|
|
/* VMFinish -- release all address space and finish VM structure */
|
|
|
|
void VMFinish(VM vm)
|
|
{
|
|
int r;
|
|
|
|
AVERT(VM, vm);
|
|
/* Descriptor must not be stored inside its own VM at this point. */
|
|
AVER(PointerAdd(vm, sizeof *vm) <= vm->block
|
|
|| PointerAdd(vm->block, VMReserved(vm)) <= (Pointer)vm);
|
|
/* All address space must have been unmapped. */
|
|
AVER(VMMapped(vm) == (Size)0);
|
|
|
|
EVENT1(VMFinish, vm);
|
|
|
|
vm->sig = SigInvalid;
|
|
|
|
r = munmap(vm->block, vm->reserved);
|
|
AVER(r == 0);
|
|
}
|
|
|
|
|
|
/* VMMap -- map the given range of memory */
|
|
|
|
Res VMMap(VM vm, Addr base, Addr limit)
|
|
{
|
|
Size size;
|
|
|
|
AVERT(VM, vm);
|
|
AVER(sizeof(void *) == sizeof(Addr));
|
|
AVER(base < limit);
|
|
AVER(base >= VMBase(vm));
|
|
AVER(limit <= VMLimit(vm));
|
|
AVER(AddrIsAligned(base, vm->pageSize));
|
|
AVER(AddrIsAligned(limit, vm->pageSize));
|
|
|
|
size = AddrOffset(base, limit);
|
|
|
|
if(mmap((void *)base, (size_t)size,
|
|
PROT_READ | PROT_WRITE | PROT_EXEC,
|
|
MAP_ANON | MAP_PRIVATE | MAP_FIXED,
|
|
-1, 0)
|
|
== MAP_FAILED) {
|
|
AVER(errno == ENOMEM); /* .assume.mmap.err */
|
|
return ResMEMORY;
|
|
}
|
|
|
|
vm->mapped += size;
|
|
AVER(VMMapped(vm) <= VMReserved(vm));
|
|
|
|
EVENT3(VMMap, vm, base, limit);
|
|
return ResOK;
|
|
}
|
|
|
|
|
|
/* VMUnmap -- unmap the given range of memory */
|
|
|
|
void VMUnmap(VM vm, Addr base, Addr limit)
|
|
{
|
|
Size size;
|
|
void *addr;
|
|
|
|
AVERT(VM, vm);
|
|
AVER(base < limit);
|
|
AVER(base >= VMBase(vm));
|
|
AVER(limit <= VMLimit(vm));
|
|
AVER(AddrIsAligned(base, vm->pageSize));
|
|
AVER(AddrIsAligned(limit, vm->pageSize));
|
|
|
|
size = AddrOffset(base, limit);
|
|
AVER(size <= VMMapped(vm));
|
|
|
|
/* see <design/vmo1/#fun.unmap.offset> */
|
|
addr = mmap((void *)base, (size_t)size,
|
|
PROT_NONE, MAP_ANON | MAP_PRIVATE | MAP_FIXED,
|
|
-1, 0);
|
|
AVER(addr == (void *)base);
|
|
|
|
vm->mapped -= size;
|
|
|
|
EVENT3(VMUnmap, vm, base, limit);
|
|
}
|
|
|
|
|
|
/* C. COPYRIGHT AND LICENSE
|
|
*
|
|
* Copyright (C) 2001-2014 Ravenbrook Limited <http://www.ravenbrook.com/>.
|
|
* All rights reserved. This is an open source license. Contact
|
|
* Ravenbrook for commercial licensing options.
|
|
*
|
|
* Redistribution and use in source and binary forms, with or without
|
|
* modification, are permitted provided that the following conditions are
|
|
* met:
|
|
*
|
|
* 1. Redistributions of source code must retain the above copyright
|
|
* notice, this list of conditions and the following disclaimer.
|
|
*
|
|
* 2. 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.
|
|
*
|
|
* 3. Redistributions in any form must be accompanied by information on how
|
|
* to obtain complete source code for this software and any accompanying
|
|
* software that uses this software. The source code must either be
|
|
* included in the distribution or be available for no more than the cost
|
|
* of distribution plus a nominal fee, and must be freely redistributable
|
|
* under reasonable conditions. For an executable file, complete source
|
|
* code means the source code for all modules it contains. It does not
|
|
* include source code for modules or files that typically accompany the
|
|
* major components of the operating system on which the executable file
|
|
* runs.
|
|
*
|
|
* 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, FITNESS FOR A PARTICULAR
|
|
* PURPOSE, OR NON-INFRINGEMENT, ARE DISCLAIMED. IN NO EVENT SHALL THE
|
|
* COPYRIGHT HOLDERS AND 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.
|
|
*/
|