IABSD.fr/src/sys/uvm/uvm_pmap.h

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• Author : claudio
  Date : 2025-06-02 18:49:04
  Hash : ac93a255
  Message : Collect uvm_swapout_threads(), pmap_collect() and __HAVE_PMAP_COLLECT and take them behind the shed. The uvm code used to call into pmap_collect is overly optimistic and thinks that a process that has all its thread sleeping will remain like that for while without holding any relevant locks. This is combined with the fact that pmap_collect functions are not MP safe. The result are bad use-after-free errors. Since only a few archs implement this feature it is probably better to just remove it then trying to fix all of the issues. OK mpi@, kettenis@, deraadt@

• sys/uvm/uvm_pmap.h

• /*	$OpenBSD: uvm_pmap.h,v 1.37 2025/06/02 18:49:04 claudio Exp $	*/
  /*	$NetBSD: uvm_pmap.h,v 1.1 2000/06/27 09:00:14 mrg Exp $	*/
  
  /* 
   * Copyright (c) 1991, 1993
   *	The Regents of the University of California.  All rights reserved.
   *
   * This code is derived from software contributed to Berkeley by
   * The Mach Operating System project at Carnegie-Mellon University.
   *
   * 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. Neither the name of the University nor the names of its contributors
   *    may be used to endorse or promote products derived from this software
   *    without specific prior written permission.
   *
   * THIS SOFTWARE IS PROVIDED BY THE REGENTS 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 REGENTS 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.
   *
   *	@(#)pmap.h	8.1 (Berkeley) 6/11/93
   *
   *
   * Copyright (c) 1987, 1990 Carnegie-Mellon University.
   * All rights reserved.
   *
   * Author: Avadis Tevanian, Jr.
   * 
   * Permission to use, copy, modify and distribute this software and
   * its documentation is hereby granted, provided that both the copyright
   * notice and this permission notice appear in all copies of the
   * software, derivative works or modified versions, and any portions
   * thereof, and that both notices appear in supporting documentation.
   * 
   * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS" 
   * CONDITION.  CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND 
   * FOR ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
   * 
   * Carnegie Mellon requests users of this software to return to
   *
   *  Software Distribution Coordinator  or  Software.Distribution@CS.CMU.EDU
   *  School of Computer Science
   *  Carnegie Mellon University
   *  Pittsburgh PA 15213-3890
   *
   * any improvements or extensions that they make and grant Carnegie the
   * rights to redistribute these changes.
   */
  
  /*
   *	Machine address mapping definitions -- machine-independent
   *	section.  [For machine-dependent section, see "machine/pmap.h".]
   */
  
  #ifndef	_PMAP_VM_
  #define	_PMAP_VM_
  
  struct proc;		/* for pmap_activate()/pmap_deactivate() proto */
  
  /*
   * Each machine dependent implementation is expected to
   * keep certain statistics.  They may do this anyway they
   * so choose, but are expected to return the statistics
   * in the following structure.
   */
  struct pmap_statistics {
  	long		resident_count;	/* # of pages mapped (total)*/
  	long		wired_count;	/* # of pages wired */
  };
  typedef struct pmap_statistics	*pmap_statistics_t;
  
  #include <machine/pmap.h>
  
  /*
   * Flags passed to pmap_enter().  Note the bottom 3 bits are PROT_*
   * bits, used to indicate the access type that was made (to seed modified
   * and referenced information).
   */
  #define	PMAP_WIRED	0x00000010	/* wired mapping */
  #define	PMAP_CANFAIL	0x00000020	/* can fail if resource shortage */
  #define	PMAP_MD0	0x00000040	/* Machine dependant */
  #define	PMAP_MD1	0x00000080	/* Machine dependant */
  #define	PMAP_MD2	0x00000100	/* Machine dependant */
  #define	PMAP_MD3	0x00000200	/* Machine dependant */
  
  #ifndef PMAP_WC
  #define PMAP_WC		0
  #endif
  
  #ifndef PMAP_PREFER
  #define PMAP_PREFER_ALIGN()	0
  #define PMAP_PREFER_OFFSET(off)	0
  #endif
  
  #ifdef _KERNEL
  __BEGIN_DECLS
  #ifndef	pmap_activate
  void		 pmap_activate(struct proc *);
  #endif
  #ifndef	pmap_deactivate
  void		 pmap_deactivate(struct proc *);
  #endif
  #ifndef	pmap_unwire
  void		 pmap_unwire(pmap_t, vaddr_t);
  #endif
  
  #if !defined(pmap_clear_modify)
  boolean_t	 pmap_clear_modify(struct vm_page *);
  #endif
  #if !defined(pmap_clear_reference)
  boolean_t	 pmap_clear_reference(struct vm_page *);
  #endif
  
  #if !defined(pmap_copy_page)
  void		 pmap_copy_page(struct vm_page *, struct vm_page *);
  #endif
  struct pmap 	 *pmap_create(void);
  void		 pmap_destroy(pmap_t);
  int		 pmap_enter(pmap_t,
  		    vaddr_t, paddr_t, vm_prot_t, int);
  boolean_t	 pmap_extract(pmap_t, vaddr_t, paddr_t *);
  #if defined(PMAP_GROWKERNEL)
  vaddr_t		 pmap_growkernel(vaddr_t);
  #endif
  
  void		 pmap_init(void);
  
  void		 pmap_kenter_pa(vaddr_t, paddr_t, vm_prot_t);
  void		 pmap_kremove(vaddr_t, vsize_t);
  #if !defined(pmap_is_modified)
  boolean_t	 pmap_is_modified(struct vm_page *);
  #endif
  #if !defined(pmap_is_referenced)
  boolean_t	 pmap_is_referenced(struct vm_page *);
  #endif
  
  void		 pmap_page_protect(struct vm_page *, vm_prot_t);
  
  #if !defined(pmap_proc_iflush)
  void		pmap_proc_iflush(struct process *, vaddr_t, vsize_t);
  #endif
  void		 pmap_protect(pmap_t, vaddr_t, vaddr_t, vm_prot_t);
  #if !defined(pmap_reference)
  void		 pmap_reference(pmap_t);
  #endif
  #if !defined(pmap_remove)
  void		 pmap_remove(pmap_t, vaddr_t, vaddr_t);
  #endif
  #if !defined(pmap_remove_holes)
  void		pmap_remove_holes(struct vmspace *);
  #endif
  #if !defined(pmap_update)
  void		 pmap_update(pmap_t);
  #endif
  #if !defined(pmap_zero_page)
  void		 pmap_zero_page(struct vm_page *);
  #endif
  
  #if defined(PMAP_STEAL_MEMORY)
  vaddr_t		 pmap_steal_memory(vsize_t, vaddr_t *, vaddr_t *);
  #else
  void		 pmap_virtual_space(vaddr_t *, vaddr_t *);
  #endif
  
  #if defined(__HAVE_PMAP_POPULATE)
  void		pmap_populate(pmap_t, vaddr_t);
  #endif
  
  #if defined(__HAVE_PMAP_PURGE)
  void		pmap_purge(struct proc *);
  #endif
  
  /* nested pmaps are used in i386/amd64 vmm */
  #ifndef pmap_nested
  #define pmap_nested(pm) 0
  #endif
  
  __END_DECLS
  #endif	/* kernel*/
  
  #endif /* _PMAP_VM_ */