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freebsd-skq/sys/vm/vm_extern.h
Konstantin Belousov df08823d07 Improve MD page fault handlers. 
Centralize calculation of signal and ucode delivered on unhandled page
fault in new function vm_fault_trap().  MD trap_pfault() now almost
always uses the signal numbers and error codes calculated in
consistent MI way.

This introduces the protection fault compatibility sysctls to all
non-x86 architectures which did not have that bug, but apparently they
were already much more wrong in selecting delivered signals on
protection violations.

Change the delivered signal for accesses to mapped area after the
backing object was truncated.  According to POSIX description for
mmap(2):
   The system shall always zero-fill any partial page at the end of an
   object. Further, the system shall never write out any modified
   portions of the last page of an object which are beyond its
   end. References within the address range starting at pa and
   continuing for len bytes to whole pages following the end of an
   object shall result in delivery of a SIGBUS signal.

   An implementation may generate SIGBUS signals when a reference
   would cause an error in the mapped object, such as out-of-space
   condition.
Adjust according to the description, keeping the existing
compatibility code for SIGSEGV/SIGBUS on protection failures.

For situations where kernel cannot handle page fault due to resource
limit enforcement, SIGBUS with a new error code BUS_OBJERR is
delivered.  Also, provide a new error code SEGV_PKUERR for SIGSEGV on
amd64 due to protection key access violation.

vm_fault_hold() is renamed to vm_fault().  Fixed some nits in
trap_pfault()s like mis-interpreting Mach errors as errnos.  Removed
unneeded truncations of the fault addresses reported by hardware.

PR:	211924
Reviewed by:	alc
Discussed with:	jilles, markj
Sponsored by:	The FreeBSD Foundation
MFC after:	1 week
Differential revision:	https://reviews.freebsd.org/D21566
2019-09-27 18:43:36 +00:00

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/*-
* SPDX-License-Identifier: BSD-3-Clause
*
* Copyright (c) 1992, 1993
* The Regents of the University of California. All rights reserved.
*
* 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.
*
* @(#)vm_extern.h 8.2 (Berkeley) 1/12/94
* $FreeBSD$
*/
#ifndef _VM_EXTERN_H_
#define _VM_EXTERN_H_
struct pmap;
struct proc;
struct vmspace;
struct vnode;
struct vmem;
#ifdef _KERNEL
struct cdev;
struct cdevsw;
struct domainset;
/* These operate on kernel virtual addresses only. */
vm_offset_t kva_alloc(vm_size_t);
void kva_free(vm_offset_t, vm_size_t);
/* These operate on pageable virtual addresses. */
vm_offset_t kmap_alloc_wait(vm_map_t, vm_size_t);
void kmap_free_wakeup(vm_map_t, vm_offset_t, vm_size_t);
/* These operate on virtual addresses backed by memory. */
vm_offset_t kmem_alloc_attr(vm_size_t size, int flags,
vm_paddr_t low, vm_paddr_t high, vm_memattr_t memattr);
vm_offset_t kmem_alloc_attr_domainset(struct domainset *ds, vm_size_t size,
int flags, vm_paddr_t low, vm_paddr_t high, vm_memattr_t memattr);
vm_offset_t kmem_alloc_contig(vm_size_t size, int flags,
vm_paddr_t low, vm_paddr_t high, u_long alignment, vm_paddr_t boundary,
vm_memattr_t memattr);
vm_offset_t kmem_alloc_contig_domainset(struct domainset *ds, vm_size_t size,
int flags, vm_paddr_t low, vm_paddr_t high, u_long alignment,
vm_paddr_t boundary, vm_memattr_t memattr);
vm_offset_t kmem_malloc(vm_size_t size, int flags);
vm_offset_t kmem_malloc_domainset(struct domainset *ds, vm_size_t size,
int flags);
void kmem_free(vm_offset_t addr, vm_size_t size);
/* This provides memory for previously allocated address space. */
int kmem_back(vm_object_t, vm_offset_t, vm_size_t, int);
int kmem_back_domain(int, vm_object_t, vm_offset_t, vm_size_t, int);
void kmem_unback(vm_object_t, vm_offset_t, vm_size_t);
/* Bootstrapping. */
void kmem_bootstrap_free(vm_offset_t, vm_size_t);
vm_map_t kmem_suballoc(vm_map_t, vm_offset_t *, vm_offset_t *, vm_size_t,
boolean_t);
void kmem_init(vm_offset_t, vm_offset_t);
void kmem_init_zero_region(void);
void kmeminit(void);
int kernacc(void *, int, int);
int useracc(void *, int, int);
int vm_fault(vm_map_t map, vm_offset_t vaddr, vm_prot_t fault_type,
int fault_flags, vm_page_t *m_hold);
void vm_fault_copy_entry(vm_map_t, vm_map_t, vm_map_entry_t, vm_map_entry_t,
vm_ooffset_t *);
int vm_fault_disable_pagefaults(void);
void vm_fault_enable_pagefaults(int save);
int vm_fault_quick_hold_pages(vm_map_t map, vm_offset_t addr, vm_size_t len,
vm_prot_t prot, vm_page_t *ma, int max_count);
int vm_fault_trap(vm_map_t map, vm_offset_t vaddr, vm_prot_t fault_type,
int fault_flags, int *signo, int *ucode);
int vm_forkproc(struct thread *, struct proc *, struct thread *,
struct vmspace *, int);
void vm_waitproc(struct proc *);
int vm_mmap(vm_map_t, vm_offset_t *, vm_size_t, vm_prot_t, vm_prot_t, int,
objtype_t, void *, vm_ooffset_t);
int vm_mmap_object(vm_map_t, vm_offset_t *, vm_size_t, vm_prot_t,
vm_prot_t, int, vm_object_t, vm_ooffset_t, boolean_t, struct thread *);
int vm_mmap_to_errno(int rv);
int vm_mmap_cdev(struct thread *, vm_size_t, vm_prot_t, vm_prot_t *,
int *, struct cdev *, struct cdevsw *, vm_ooffset_t *, vm_object_t *);
int vm_mmap_vnode(struct thread *, vm_size_t, vm_prot_t, vm_prot_t *, int *,
struct vnode *, vm_ooffset_t *, vm_object_t *, boolean_t *);
void vm_set_page_size(void);
void vm_sync_icache(vm_map_t, vm_offset_t, vm_size_t);
typedef int (*pmap_pinit_t)(struct pmap *pmap);
struct vmspace *vmspace_alloc(vm_offset_t, vm_offset_t, pmap_pinit_t);
struct vmspace *vmspace_fork(struct vmspace *, vm_ooffset_t *);
int vmspace_exec(struct proc *, vm_offset_t, vm_offset_t);
int vmspace_unshare(struct proc *);
void vmspace_exit(struct thread *);
struct vmspace *vmspace_acquire_ref(struct proc *);
void vmspace_free(struct vmspace *);
void vmspace_exitfree(struct proc *);
void vmspace_switch_aio(struct vmspace *);
void vnode_pager_setsize(struct vnode *, vm_ooffset_t);
int vslock(void *, size_t);
void vsunlock(void *, size_t);
struct sf_buf *vm_imgact_map_page(vm_object_t object, vm_ooffset_t offset);
void vm_imgact_unmap_page(struct sf_buf *sf);
void vm_thread_dispose(struct thread *td);
int vm_thread_new(struct thread *td, int pages);
u_int vm_active_count(void);
u_int vm_inactive_count(void);
u_int vm_laundry_count(void);
u_int vm_wait_count(void);
#endif /* _KERNEL */
#endif /* !_VM_EXTERN_H_ */
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