Index: stable/11/lib/libc/sys/minherit.2 =================================================================== --- stable/11/lib/libc/sys/minherit.2 (revision 319276) +++ stable/11/lib/libc/sys/minherit.2 (revision 319277) @@ -1,139 +1,151 @@ .\" $FreeBSD$ .\" .\" Copyright (c) 1991, 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. .\" 4. 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. .\" .\" @(#)minherit.2 8.1 (Berkeley) 6/9/93 .\" -.Dd October 30, 2007 +.Dd March 15, 2017 .Dt MINHERIT 2 .Os .Sh NAME .Nm minherit .Nd control the inheritance of pages .Sh LIBRARY .Lb libc .Sh SYNOPSIS .In sys/mman.h .Ft int .Fn minherit "void *addr" "size_t len" "int inherit" .Sh DESCRIPTION The .Fn minherit system call changes the specified pages to have the inheritance characteristic .Fa inherit . Not all implementations will guarantee that the inheritance characteristic can be set on a page basis; the granularity of changes may be as large as an entire region. .Fx is capable of adjusting inheritance characteristics on a page basis. Inheritance only effects children created by .Fn fork . It has no effect on .Fn exec . exec'd processes replace their address space entirely. This system call also has no effect on the parent's address space (other than to potentially share the address space with its children). .Pp Inheritance is a rather esoteric feature largely superseded by the .Dv MAP_SHARED feature of .Fn mmap . However, it is possible to use .Fn minherit to share a block of memory between parent and child that has been mapped .Dv MAP_PRIVATE . That is, modifications made by parent or child are shared but the original underlying file is left untouched. .Bl -tag -width ".Dv INHERIT_SHARE" .It Dv INHERIT_SHARE This option causes the address space in question to be shared between parent and child. It has no effect on how the original underlying backing store was mapped. .It Dv INHERIT_NONE This option prevents the address space in question from being inherited at all. The address space will be unmapped in the child. .It Dv INHERIT_COPY This option causes the child to inherit the address space as copy-on-write. This option also has an unfortunate side effect of causing the parent address space to become copy-on-write when the parent forks. If the original mapping was .Dv MAP_SHARED , it will no longer be shared in the parent after the parent forks and there is no way to get the previous shared-backing-store mapping without unmapping and remapping the address space in the parent. +.It Dv INHERIT_ZERO +This option causes the address space in question to be mapped as new +anonymous pages, +which would be initialized to all zero bytes, +in the child process. .El .Sh RETURN VALUES .Rv -std minherit .Sh ERRORS The .Fn minherit system call will fail if: .Bl -tag -width Er .It Bq Er EINVAL The virtual address range specified by the .Fa addr and .Fa len arguments is not valid. .It Bq Er EACCES The flags specified by the .Fa inherit argument were not valid for the pages specified by the .Fa addr and .Fa len arguments. .El .Sh SEE ALSO .Xr fork 2 , .Xr madvise 2 , .Xr mincore 2 , .Xr mprotect 2 , .Xr msync 2 , .Xr munmap 2 , .Xr rfork 2 .Sh HISTORY The .Fn minherit system call first appeared in .Ox and then in .Fx 2.2 . +.Pp +The +.Dv INHERIT_ZERO +support first appeared in +.Ox 5.6 +and then in +.Fx 12.0 . .Sh BUGS Once you set inheritance to .Dv MAP_PRIVATE or .Dv MAP_SHARED , there is no way to recover the original copy-on-write semantics short of unmapping and remapping the area. Index: stable/11/sys/sys/mman.h =================================================================== --- stable/11/sys/sys/mman.h (revision 319276) +++ stable/11/sys/sys/mman.h (revision 319277) @@ -1,278 +1,279 @@ /*- * Copyright (c) 1982, 1986, 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. * 4. 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. * * @(#)mman.h 8.2 (Berkeley) 1/9/95 * $FreeBSD$ */ #ifndef _SYS_MMAN_H_ #define _SYS_MMAN_H_ #include #include #if __BSD_VISIBLE /* * Inheritance for minherit() */ #define INHERIT_SHARE 0 #define INHERIT_COPY 1 #define INHERIT_NONE 2 +#define INHERIT_ZERO 3 #endif /* * Protections are chosen from these bits, or-ed together */ #define PROT_NONE 0x00 /* no permissions */ #define PROT_READ 0x01 /* pages can be read */ #define PROT_WRITE 0x02 /* pages can be written */ #define PROT_EXEC 0x04 /* pages can be executed */ /* * Flags contain sharing type and options. * Sharing types; choose one. */ #define MAP_SHARED 0x0001 /* share changes */ #define MAP_PRIVATE 0x0002 /* changes are private */ #if __BSD_VISIBLE #define MAP_COPY MAP_PRIVATE /* Obsolete */ #endif /* * Other flags */ #define MAP_FIXED 0x0010 /* map addr must be exactly as requested */ #if __BSD_VISIBLE #define MAP_RESERVED0020 0x0020 /* previously unimplemented MAP_RENAME */ #define MAP_RESERVED0040 0x0040 /* previously unimplemented MAP_NORESERVE */ #define MAP_RESERVED0080 0x0080 /* previously misimplemented MAP_INHERIT */ #define MAP_RESERVED0100 0x0100 /* previously unimplemented MAP_NOEXTEND */ #define MAP_HASSEMAPHORE 0x0200 /* region may contain semaphores */ #define MAP_STACK 0x0400 /* region grows down, like a stack */ #define MAP_NOSYNC 0x0800 /* page to but do not sync underlying file */ /* * Mapping type */ #define MAP_FILE 0x0000 /* map from file (default) */ #define MAP_ANON 0x1000 /* allocated from memory, swap space */ #ifndef _KERNEL #define MAP_ANONYMOUS MAP_ANON /* For compatibility. */ #endif /* !_KERNEL */ /* * Extended flags */ #define MAP_EXCL 0x00004000 /* for MAP_FIXED, fail if address is used */ #define MAP_NOCORE 0x00020000 /* dont include these pages in a coredump */ #define MAP_PREFAULT_READ 0x00040000 /* prefault mapping for reading */ #ifdef __LP64__ #define MAP_32BIT 0x00080000 /* map in the low 2GB of address space */ #endif /* * Request specific alignment (n == log2 of the desired alignment). * * MAP_ALIGNED_SUPER requests optimal superpage alignment, but does * not enforce a specific alignment. */ #define MAP_ALIGNED(n) ((n) << MAP_ALIGNMENT_SHIFT) #define MAP_ALIGNMENT_SHIFT 24 #define MAP_ALIGNMENT_MASK MAP_ALIGNED(0xff) #define MAP_ALIGNED_SUPER MAP_ALIGNED(1) /* align on a superpage */ #endif /* __BSD_VISIBLE */ #if __POSIX_VISIBLE >= 199309 /* * Process memory locking */ #define MCL_CURRENT 0x0001 /* Lock only current memory */ #define MCL_FUTURE 0x0002 /* Lock all future memory as well */ #endif /* * Error return from mmap() */ #define MAP_FAILED ((void *)-1) /* * msync() flags */ #define MS_SYNC 0x0000 /* msync synchronously */ #define MS_ASYNC 0x0001 /* return immediately */ #define MS_INVALIDATE 0x0002 /* invalidate all cached data */ /* * Advice to madvise */ #define _MADV_NORMAL 0 /* no further special treatment */ #define _MADV_RANDOM 1 /* expect random page references */ #define _MADV_SEQUENTIAL 2 /* expect sequential page references */ #define _MADV_WILLNEED 3 /* will need these pages */ #define _MADV_DONTNEED 4 /* dont need these pages */ #if __BSD_VISIBLE #define MADV_NORMAL _MADV_NORMAL #define MADV_RANDOM _MADV_RANDOM #define MADV_SEQUENTIAL _MADV_SEQUENTIAL #define MADV_WILLNEED _MADV_WILLNEED #define MADV_DONTNEED _MADV_DONTNEED #define MADV_FREE 5 /* dont need these pages, and junk contents */ #define MADV_NOSYNC 6 /* try to avoid flushes to physical media */ #define MADV_AUTOSYNC 7 /* revert to default flushing strategy */ #define MADV_NOCORE 8 /* do not include these pages in a core file */ #define MADV_CORE 9 /* revert to including pages in a core file */ #define MADV_PROTECT 10 /* protect process from pageout kill */ /* * Return bits from mincore */ #define MINCORE_INCORE 0x1 /* Page is incore */ #define MINCORE_REFERENCED 0x2 /* Page has been referenced by us */ #define MINCORE_MODIFIED 0x4 /* Page has been modified by us */ #define MINCORE_REFERENCED_OTHER 0x8 /* Page has been referenced */ #define MINCORE_MODIFIED_OTHER 0x10 /* Page has been modified */ #define MINCORE_SUPER 0x20 /* Page is a "super" page */ /* * Anonymous object constant for shm_open(). */ #define SHM_ANON ((char *)1) #endif /* __BSD_VISIBLE */ /* * XXX missing POSIX_TYPED_MEM_* macros and * posix_typed_mem_info structure. */ #if __POSIX_VISIBLE >= 200112 #define POSIX_MADV_NORMAL _MADV_NORMAL #define POSIX_MADV_RANDOM _MADV_RANDOM #define POSIX_MADV_SEQUENTIAL _MADV_SEQUENTIAL #define POSIX_MADV_WILLNEED _MADV_WILLNEED #define POSIX_MADV_DONTNEED _MADV_DONTNEED #endif #ifndef _MODE_T_DECLARED typedef __mode_t mode_t; #define _MODE_T_DECLARED #endif #ifndef _OFF_T_DECLARED typedef __off_t off_t; #define _OFF_T_DECLARED #endif #ifndef _SIZE_T_DECLARED typedef __size_t size_t; #define _SIZE_T_DECLARED #endif #if defined(_KERNEL) || defined(_WANT_FILE) #include #include #include #include #include struct file; struct shmfd { size_t shm_size; vm_object_t shm_object; int shm_refs; uid_t shm_uid; gid_t shm_gid; mode_t shm_mode; int shm_kmappings; /* * Values maintained solely to make this a better-behaved file * descriptor for fstat() to run on. */ struct timespec shm_atime; struct timespec shm_mtime; struct timespec shm_ctime; struct timespec shm_birthtime; ino_t shm_ino; struct label *shm_label; /* MAC label */ const char *shm_path; struct rangelock shm_rl; struct mtx shm_mtx; }; #endif #ifdef _KERNEL int shm_map(struct file *fp, size_t size, off_t offset, void **memp); int shm_unmap(struct file *fp, void *mem, size_t size); int shm_access(struct shmfd *shmfd, struct ucred *ucred, int flags); struct shmfd *shm_alloc(struct ucred *ucred, mode_t mode); struct shmfd *shm_hold(struct shmfd *shmfd); void shm_drop(struct shmfd *shmfd); int shm_dotruncate(struct shmfd *shmfd, off_t length); extern struct fileops shm_ops; #else /* !_KERNEL */ __BEGIN_DECLS /* * XXX not yet implemented: posix_mem_offset(), posix_typed_mem_get_info(), * posix_typed_mem_open(). */ #if __BSD_VISIBLE int getpagesizes(size_t *, int); int madvise(void *, size_t, int); int mincore(const void *, size_t, char *); int minherit(void *, size_t, int); #endif int mlock(const void *, size_t); #ifndef _MMAP_DECLARED #define _MMAP_DECLARED void * mmap(void *, size_t, int, int, int, off_t); #endif int mprotect(const void *, size_t, int); int msync(void *, size_t, int); int munlock(const void *, size_t); int munmap(void *, size_t); #if __POSIX_VISIBLE >= 200112 int posix_madvise(void *, size_t, int); #endif #if __POSIX_VISIBLE >= 199309 int mlockall(int); int munlockall(void); int shm_open(const char *, int, mode_t); int shm_unlink(const char *); #endif __END_DECLS #endif /* !_KERNEL */ #endif /* !_SYS_MMAN_H_ */ Index: stable/11/sys/vm/vm.h =================================================================== --- stable/11/sys/vm/vm.h (revision 319276) +++ stable/11/sys/vm/vm.h (revision 319277) @@ -1,154 +1,155 @@ /*- * Copyright (c) 1991, 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. * 4. 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.h 8.2 (Berkeley) 12/13/93 * @(#)vm_prot.h 8.1 (Berkeley) 6/11/93 * @(#)vm_inherit.h 8.1 (Berkeley) 6/11/93 * * Copyright (c) 1987, 1990 Carnegie-Mellon University. * All rights reserved. * * Authors: Avadis Tevanian, Jr., Michael Wayne Young * * 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. * * $FreeBSD$ */ #ifndef VM_H #define VM_H #include typedef char vm_inherit_t; /* inheritance codes */ #define VM_INHERIT_SHARE ((vm_inherit_t) 0) #define VM_INHERIT_COPY ((vm_inherit_t) 1) #define VM_INHERIT_NONE ((vm_inherit_t) 2) +#define VM_INHERIT_ZERO ((vm_inherit_t) 3) #define VM_INHERIT_DEFAULT VM_INHERIT_COPY typedef u_char vm_prot_t; /* protection codes */ #define VM_PROT_NONE ((vm_prot_t) 0x00) #define VM_PROT_READ ((vm_prot_t) 0x01) #define VM_PROT_WRITE ((vm_prot_t) 0x02) #define VM_PROT_EXECUTE ((vm_prot_t) 0x04) #define VM_PROT_COPY ((vm_prot_t) 0x08) /* copy-on-read */ #define VM_PROT_ALL (VM_PROT_READ|VM_PROT_WRITE|VM_PROT_EXECUTE) #define VM_PROT_RW (VM_PROT_READ|VM_PROT_WRITE) #define VM_PROT_DEFAULT VM_PROT_ALL enum obj_type { OBJT_DEFAULT, OBJT_SWAP, OBJT_VNODE, OBJT_DEVICE, OBJT_PHYS, OBJT_DEAD, OBJT_SG, OBJT_MGTDEVICE }; typedef u_char objtype_t; union vm_map_object; typedef union vm_map_object vm_map_object_t; struct vm_map_entry; typedef struct vm_map_entry *vm_map_entry_t; struct vm_map; typedef struct vm_map *vm_map_t; struct vm_object; typedef struct vm_object *vm_object_t; #ifndef _KERNEL /* * This is defined in for the kernel so that non-vm kernel * sources (mainly Mach-derived ones such as ddb) don't have to include * vm stuff. Defining it there for applications might break things. * Define it here for "applications" that include vm headers (e.g., * genassym). */ typedef int boolean_t; /* * The exact set of memory attributes is machine dependent. However, * every machine is required to define VM_MEMATTR_DEFAULT and * VM_MEMATTR_UNCACHEABLE. */ typedef char vm_memattr_t; /* memory attribute codes */ /* * This is defined in for the kernel so that vnode_if.h * doesn't have to include . */ struct vm_page; typedef struct vm_page *vm_page_t; #endif /* _KERNEL */ struct vm_reserv; typedef struct vm_reserv *vm_reserv_t; /* * Information passed from the machine-independant VM initialization code * for use by machine-dependant code (mainly for MMU support) */ struct kva_md_info { vm_offset_t buffer_sva; vm_offset_t buffer_eva; vm_offset_t clean_sva; vm_offset_t clean_eva; }; extern struct kva_md_info kmi; extern void vm_ksubmap_init(struct kva_md_info *); extern int old_mlock; struct ucred; int swap_reserve(vm_ooffset_t incr); int swap_reserve_by_cred(vm_ooffset_t incr, struct ucred *cred); void swap_reserve_force(vm_ooffset_t incr); void swap_release(vm_ooffset_t decr); void swap_release_by_cred(vm_ooffset_t decr, struct ucred *cred); void swapper(void); #endif /* VM_H */ Index: stable/11/sys/vm/vm_map.c =================================================================== --- stable/11/sys/vm/vm_map.c (revision 319276) +++ stable/11/sys/vm/vm_map.c (revision 319277) @@ -1,4335 +1,4364 @@ /*- * 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. * 4. 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. * * from: @(#)vm_map.c 8.3 (Berkeley) 1/12/94 * * * Copyright (c) 1987, 1990 Carnegie-Mellon University. * All rights reserved. * * Authors: Avadis Tevanian, Jr., Michael Wayne Young * * 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. */ /* * Virtual memory mapping module. */ #include __FBSDID("$FreeBSD$"); #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include /* * Virtual memory maps provide for the mapping, protection, * and sharing of virtual memory objects. In addition, * this module provides for an efficient virtual copy of * memory from one map to another. * * Synchronization is required prior to most operations. * * Maps consist of an ordered doubly-linked list of simple * entries; a self-adjusting binary search tree of these * entries is used to speed up lookups. * * Since portions of maps are specified by start/end addresses, * which may not align with existing map entries, all * routines merely "clip" entries to these start/end values. * [That is, an entry is split into two, bordering at a * start or end value.] Note that these clippings may not * always be necessary (as the two resulting entries are then * not changed); however, the clipping is done for convenience. * * As mentioned above, virtual copy operations are performed * by copying VM object references from one map to * another, and then marking both regions as copy-on-write. */ static struct mtx map_sleep_mtx; static uma_zone_t mapentzone; static uma_zone_t kmapentzone; static uma_zone_t mapzone; static uma_zone_t vmspace_zone; static int vmspace_zinit(void *mem, int size, int flags); static int vm_map_zinit(void *mem, int ize, int flags); static void _vm_map_init(vm_map_t map, pmap_t pmap, vm_offset_t min, vm_offset_t max); static void vm_map_entry_deallocate(vm_map_entry_t entry, boolean_t system_map); static void vm_map_entry_dispose(vm_map_t map, vm_map_entry_t entry); static void vm_map_entry_unwire(vm_map_t map, vm_map_entry_t entry); static void vm_map_pmap_enter(vm_map_t map, vm_offset_t addr, vm_prot_t prot, vm_object_t object, vm_pindex_t pindex, vm_size_t size, int flags); #ifdef INVARIANTS static void vm_map_zdtor(void *mem, int size, void *arg); static void vmspace_zdtor(void *mem, int size, void *arg); #endif static int vm_map_stack_locked(vm_map_t map, vm_offset_t addrbos, vm_size_t max_ssize, vm_size_t growsize, vm_prot_t prot, vm_prot_t max, int cow); static void vm_map_wire_entry_failure(vm_map_t map, vm_map_entry_t entry, vm_offset_t failed_addr); #define ENTRY_CHARGED(e) ((e)->cred != NULL || \ ((e)->object.vm_object != NULL && (e)->object.vm_object->cred != NULL && \ !((e)->eflags & MAP_ENTRY_NEEDS_COPY))) /* * PROC_VMSPACE_{UN,}LOCK() can be a noop as long as vmspaces are type * stable. */ #define PROC_VMSPACE_LOCK(p) do { } while (0) #define PROC_VMSPACE_UNLOCK(p) do { } while (0) /* * VM_MAP_RANGE_CHECK: [ internal use only ] * * Asserts that the starting and ending region * addresses fall within the valid range of the map. */ #define VM_MAP_RANGE_CHECK(map, start, end) \ { \ if (start < vm_map_min(map)) \ start = vm_map_min(map); \ if (end > vm_map_max(map)) \ end = vm_map_max(map); \ if (start > end) \ start = end; \ } /* * vm_map_startup: * * Initialize the vm_map module. Must be called before * any other vm_map routines. * * Map and entry structures are allocated from the general * purpose memory pool with some exceptions: * * - The kernel map and kmem submap are allocated statically. * - Kernel map entries are allocated out of a static pool. * * These restrictions are necessary since malloc() uses the * maps and requires map entries. */ void vm_map_startup(void) { mtx_init(&map_sleep_mtx, "vm map sleep mutex", NULL, MTX_DEF); mapzone = uma_zcreate("MAP", sizeof(struct vm_map), NULL, #ifdef INVARIANTS vm_map_zdtor, #else NULL, #endif vm_map_zinit, NULL, UMA_ALIGN_PTR, UMA_ZONE_NOFREE); uma_prealloc(mapzone, MAX_KMAP); kmapentzone = uma_zcreate("KMAP ENTRY", sizeof(struct vm_map_entry), NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, UMA_ZONE_MTXCLASS | UMA_ZONE_VM); mapentzone = uma_zcreate("MAP ENTRY", sizeof(struct vm_map_entry), NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, 0); vmspace_zone = uma_zcreate("VMSPACE", sizeof(struct vmspace), NULL, #ifdef INVARIANTS vmspace_zdtor, #else NULL, #endif vmspace_zinit, NULL, UMA_ALIGN_PTR, UMA_ZONE_NOFREE); } static int vmspace_zinit(void *mem, int size, int flags) { struct vmspace *vm; vm = (struct vmspace *)mem; vm->vm_map.pmap = NULL; (void)vm_map_zinit(&vm->vm_map, sizeof(vm->vm_map), flags); PMAP_LOCK_INIT(vmspace_pmap(vm)); return (0); } static int vm_map_zinit(void *mem, int size, int flags) { vm_map_t map; map = (vm_map_t)mem; memset(map, 0, sizeof(*map)); mtx_init(&map->system_mtx, "vm map (system)", NULL, MTX_DEF | MTX_DUPOK); sx_init(&map->lock, "vm map (user)"); return (0); } #ifdef INVARIANTS static void vmspace_zdtor(void *mem, int size, void *arg) { struct vmspace *vm; vm = (struct vmspace *)mem; vm_map_zdtor(&vm->vm_map, sizeof(vm->vm_map), arg); } static void vm_map_zdtor(void *mem, int size, void *arg) { vm_map_t map; map = (vm_map_t)mem; KASSERT(map->nentries == 0, ("map %p nentries == %d on free.", map, map->nentries)); KASSERT(map->size == 0, ("map %p size == %lu on free.", map, (unsigned long)map->size)); } #endif /* INVARIANTS */ /* * Allocate a vmspace structure, including a vm_map and pmap, * and initialize those structures. The refcnt is set to 1. * * If 'pinit' is NULL then the embedded pmap is initialized via pmap_pinit(). */ struct vmspace * vmspace_alloc(vm_offset_t min, vm_offset_t max, pmap_pinit_t pinit) { struct vmspace *vm; vm = uma_zalloc(vmspace_zone, M_WAITOK); KASSERT(vm->vm_map.pmap == NULL, ("vm_map.pmap must be NULL")); if (pinit == NULL) pinit = &pmap_pinit; if (!pinit(vmspace_pmap(vm))) { uma_zfree(vmspace_zone, vm); return (NULL); } CTR1(KTR_VM, "vmspace_alloc: %p", vm); _vm_map_init(&vm->vm_map, vmspace_pmap(vm), min, max); vm->vm_refcnt = 1; vm->vm_shm = NULL; vm->vm_swrss = 0; vm->vm_tsize = 0; vm->vm_dsize = 0; vm->vm_ssize = 0; vm->vm_taddr = 0; vm->vm_daddr = 0; vm->vm_maxsaddr = 0; return (vm); } #ifdef RACCT static void vmspace_container_reset(struct proc *p) { PROC_LOCK(p); racct_set(p, RACCT_DATA, 0); racct_set(p, RACCT_STACK, 0); racct_set(p, RACCT_RSS, 0); racct_set(p, RACCT_MEMLOCK, 0); racct_set(p, RACCT_VMEM, 0); PROC_UNLOCK(p); } #endif static inline void vmspace_dofree(struct vmspace *vm) { CTR1(KTR_VM, "vmspace_free: %p", vm); /* * Make sure any SysV shm is freed, it might not have been in * exit1(). */ shmexit(vm); /* * Lock the map, to wait out all other references to it. * Delete all of the mappings and pages they hold, then call * the pmap module to reclaim anything left. */ (void)vm_map_remove(&vm->vm_map, vm->vm_map.min_offset, vm->vm_map.max_offset); pmap_release(vmspace_pmap(vm)); vm->vm_map.pmap = NULL; uma_zfree(vmspace_zone, vm); } void vmspace_free(struct vmspace *vm) { WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, NULL, "vmspace_free() called"); if (vm->vm_refcnt == 0) panic("vmspace_free: attempt to free already freed vmspace"); if (atomic_fetchadd_int(&vm->vm_refcnt, -1) == 1) vmspace_dofree(vm); } void vmspace_exitfree(struct proc *p) { struct vmspace *vm; PROC_VMSPACE_LOCK(p); vm = p->p_vmspace; p->p_vmspace = NULL; PROC_VMSPACE_UNLOCK(p); KASSERT(vm == &vmspace0, ("vmspace_exitfree: wrong vmspace")); vmspace_free(vm); } void vmspace_exit(struct thread *td) { int refcnt; struct vmspace *vm; struct proc *p; /* * Release user portion of address space. * This releases references to vnodes, * which could cause I/O if the file has been unlinked. * Need to do this early enough that we can still sleep. * * The last exiting process to reach this point releases as * much of the environment as it can. vmspace_dofree() is the * slower fallback in case another process had a temporary * reference to the vmspace. */ p = td->td_proc; vm = p->p_vmspace; atomic_add_int(&vmspace0.vm_refcnt, 1); do { refcnt = vm->vm_refcnt; if (refcnt > 1 && p->p_vmspace != &vmspace0) { /* Switch now since other proc might free vmspace */ PROC_VMSPACE_LOCK(p); p->p_vmspace = &vmspace0; PROC_VMSPACE_UNLOCK(p); pmap_activate(td); } } while (!atomic_cmpset_int(&vm->vm_refcnt, refcnt, refcnt - 1)); if (refcnt == 1) { if (p->p_vmspace != vm) { /* vmspace not yet freed, switch back */ PROC_VMSPACE_LOCK(p); p->p_vmspace = vm; PROC_VMSPACE_UNLOCK(p); pmap_activate(td); } pmap_remove_pages(vmspace_pmap(vm)); /* Switch now since this proc will free vmspace */ PROC_VMSPACE_LOCK(p); p->p_vmspace = &vmspace0; PROC_VMSPACE_UNLOCK(p); pmap_activate(td); vmspace_dofree(vm); } #ifdef RACCT if (racct_enable) vmspace_container_reset(p); #endif } /* Acquire reference to vmspace owned by another process. */ struct vmspace * vmspace_acquire_ref(struct proc *p) { struct vmspace *vm; int refcnt; PROC_VMSPACE_LOCK(p); vm = p->p_vmspace; if (vm == NULL) { PROC_VMSPACE_UNLOCK(p); return (NULL); } do { refcnt = vm->vm_refcnt; if (refcnt <= 0) { /* Avoid 0->1 transition */ PROC_VMSPACE_UNLOCK(p); return (NULL); } } while (!atomic_cmpset_int(&vm->vm_refcnt, refcnt, refcnt + 1)); if (vm != p->p_vmspace) { PROC_VMSPACE_UNLOCK(p); vmspace_free(vm); return (NULL); } PROC_VMSPACE_UNLOCK(p); return (vm); } /* * Switch between vmspaces in an AIO kernel process. * * The AIO kernel processes switch to and from a user process's * vmspace while performing an I/O operation on behalf of a user * process. The new vmspace is either the vmspace of a user process * obtained from an active AIO request or the initial vmspace of the * AIO kernel process (when it is idling). Because user processes * will block to drain any active AIO requests before proceeding in * exit() or execve(), the vmspace reference count for these vmspaces * can never be 0. This allows for a much simpler implementation than * the loop in vmspace_acquire_ref() above. Similarly, AIO kernel * processes hold an extra reference on their initial vmspace for the * life of the process so that this guarantee is true for any vmspace * passed as 'newvm'. */ void vmspace_switch_aio(struct vmspace *newvm) { struct vmspace *oldvm; /* XXX: Need some way to assert that this is an aio daemon. */ KASSERT(newvm->vm_refcnt > 0, ("vmspace_switch_aio: newvm unreferenced")); oldvm = curproc->p_vmspace; if (oldvm == newvm) return; /* * Point to the new address space and refer to it. */ curproc->p_vmspace = newvm; atomic_add_int(&newvm->vm_refcnt, 1); /* Activate the new mapping. */ pmap_activate(curthread); /* Remove the daemon's reference to the old address space. */ KASSERT(oldvm->vm_refcnt > 1, ("vmspace_switch_aio: oldvm dropping last reference")); vmspace_free(oldvm); } void _vm_map_lock(vm_map_t map, const char *file, int line) { if (map->system_map) mtx_lock_flags_(&map->system_mtx, 0, file, line); else sx_xlock_(&map->lock, file, line); map->timestamp++; } static void vm_map_process_deferred(void) { struct thread *td; vm_map_entry_t entry, next; vm_object_t object; td = curthread; entry = td->td_map_def_user; td->td_map_def_user = NULL; while (entry != NULL) { next = entry->next; if ((entry->eflags & MAP_ENTRY_VN_WRITECNT) != 0) { /* * Decrement the object's writemappings and * possibly the vnode's v_writecount. */ KASSERT((entry->eflags & MAP_ENTRY_IS_SUB_MAP) == 0, ("Submap with writecount")); object = entry->object.vm_object; KASSERT(object != NULL, ("No object for writecount")); vnode_pager_release_writecount(object, entry->start, entry->end); } vm_map_entry_deallocate(entry, FALSE); entry = next; } } void _vm_map_unlock(vm_map_t map, const char *file, int line) { if (map->system_map) mtx_unlock_flags_(&map->system_mtx, 0, file, line); else { sx_xunlock_(&map->lock, file, line); vm_map_process_deferred(); } } void _vm_map_lock_read(vm_map_t map, const char *file, int line) { if (map->system_map) mtx_lock_flags_(&map->system_mtx, 0, file, line); else sx_slock_(&map->lock, file, line); } void _vm_map_unlock_read(vm_map_t map, const char *file, int line) { if (map->system_map) mtx_unlock_flags_(&map->system_mtx, 0, file, line); else { sx_sunlock_(&map->lock, file, line); vm_map_process_deferred(); } } int _vm_map_trylock(vm_map_t map, const char *file, int line) { int error; error = map->system_map ? !mtx_trylock_flags_(&map->system_mtx, 0, file, line) : !sx_try_xlock_(&map->lock, file, line); if (error == 0) map->timestamp++; return (error == 0); } int _vm_map_trylock_read(vm_map_t map, const char *file, int line) { int error; error = map->system_map ? !mtx_trylock_flags_(&map->system_mtx, 0, file, line) : !sx_try_slock_(&map->lock, file, line); return (error == 0); } /* * _vm_map_lock_upgrade: [ internal use only ] * * Tries to upgrade a read (shared) lock on the specified map to a write * (exclusive) lock. Returns the value "0" if the upgrade succeeds and a * non-zero value if the upgrade fails. If the upgrade fails, the map is * returned without a read or write lock held. * * Requires that the map be read locked. */ int _vm_map_lock_upgrade(vm_map_t map, const char *file, int line) { unsigned int last_timestamp; if (map->system_map) { mtx_assert_(&map->system_mtx, MA_OWNED, file, line); } else { if (!sx_try_upgrade_(&map->lock, file, line)) { last_timestamp = map->timestamp; sx_sunlock_(&map->lock, file, line); vm_map_process_deferred(); /* * If the map's timestamp does not change while the * map is unlocked, then the upgrade succeeds. */ sx_xlock_(&map->lock, file, line); if (last_timestamp != map->timestamp) { sx_xunlock_(&map->lock, file, line); return (1); } } } map->timestamp++; return (0); } void _vm_map_lock_downgrade(vm_map_t map, const char *file, int line) { if (map->system_map) { mtx_assert_(&map->system_mtx, MA_OWNED, file, line); } else sx_downgrade_(&map->lock, file, line); } /* * vm_map_locked: * * Returns a non-zero value if the caller holds a write (exclusive) lock * on the specified map and the value "0" otherwise. */ int vm_map_locked(vm_map_t map) { if (map->system_map) return (mtx_owned(&map->system_mtx)); else return (sx_xlocked(&map->lock)); } #ifdef INVARIANTS static void _vm_map_assert_locked(vm_map_t map, const char *file, int line) { if (map->system_map) mtx_assert_(&map->system_mtx, MA_OWNED, file, line); else sx_assert_(&map->lock, SA_XLOCKED, file, line); } #define VM_MAP_ASSERT_LOCKED(map) \ _vm_map_assert_locked(map, LOCK_FILE, LOCK_LINE) #else #define VM_MAP_ASSERT_LOCKED(map) #endif /* * _vm_map_unlock_and_wait: * * Atomically releases the lock on the specified map and puts the calling * thread to sleep. The calling thread will remain asleep until either * vm_map_wakeup() is performed on the map or the specified timeout is * exceeded. * * WARNING! This function does not perform deferred deallocations of * objects and map entries. Therefore, the calling thread is expected to * reacquire the map lock after reawakening and later perform an ordinary * unlock operation, such as vm_map_unlock(), before completing its * operation on the map. */ int _vm_map_unlock_and_wait(vm_map_t map, int timo, const char *file, int line) { mtx_lock(&map_sleep_mtx); if (map->system_map) mtx_unlock_flags_(&map->system_mtx, 0, file, line); else sx_xunlock_(&map->lock, file, line); return (msleep(&map->root, &map_sleep_mtx, PDROP | PVM, "vmmaps", timo)); } /* * vm_map_wakeup: * * Awaken any threads that have slept on the map using * vm_map_unlock_and_wait(). */ void vm_map_wakeup(vm_map_t map) { /* * Acquire and release map_sleep_mtx to prevent a wakeup() * from being performed (and lost) between the map unlock * and the msleep() in _vm_map_unlock_and_wait(). */ mtx_lock(&map_sleep_mtx); mtx_unlock(&map_sleep_mtx); wakeup(&map->root); } void vm_map_busy(vm_map_t map) { VM_MAP_ASSERT_LOCKED(map); map->busy++; } void vm_map_unbusy(vm_map_t map) { VM_MAP_ASSERT_LOCKED(map); KASSERT(map->busy, ("vm_map_unbusy: not busy")); if (--map->busy == 0 && (map->flags & MAP_BUSY_WAKEUP)) { vm_map_modflags(map, 0, MAP_BUSY_WAKEUP); wakeup(&map->busy); } } void vm_map_wait_busy(vm_map_t map) { VM_MAP_ASSERT_LOCKED(map); while (map->busy) { vm_map_modflags(map, MAP_BUSY_WAKEUP, 0); if (map->system_map) msleep(&map->busy, &map->system_mtx, 0, "mbusy", 0); else sx_sleep(&map->busy, &map->lock, 0, "mbusy", 0); } map->timestamp++; } long vmspace_resident_count(struct vmspace *vmspace) { return pmap_resident_count(vmspace_pmap(vmspace)); } /* * vm_map_create: * * Creates and returns a new empty VM map with * the given physical map structure, and having * the given lower and upper address bounds. */ vm_map_t vm_map_create(pmap_t pmap, vm_offset_t min, vm_offset_t max) { vm_map_t result; result = uma_zalloc(mapzone, M_WAITOK); CTR1(KTR_VM, "vm_map_create: %p", result); _vm_map_init(result, pmap, min, max); return (result); } /* * Initialize an existing vm_map structure * such as that in the vmspace structure. */ static void _vm_map_init(vm_map_t map, pmap_t pmap, vm_offset_t min, vm_offset_t max) { map->header.next = map->header.prev = &map->header; map->needs_wakeup = FALSE; map->system_map = 0; map->pmap = pmap; map->min_offset = min; map->max_offset = max; map->flags = 0; map->root = NULL; map->timestamp = 0; map->busy = 0; } void vm_map_init(vm_map_t map, pmap_t pmap, vm_offset_t min, vm_offset_t max) { _vm_map_init(map, pmap, min, max); mtx_init(&map->system_mtx, "system map", NULL, MTX_DEF | MTX_DUPOK); sx_init(&map->lock, "user map"); } /* * vm_map_entry_dispose: [ internal use only ] * * Inverse of vm_map_entry_create. */ static void vm_map_entry_dispose(vm_map_t map, vm_map_entry_t entry) { uma_zfree(map->system_map ? kmapentzone : mapentzone, entry); } /* * vm_map_entry_create: [ internal use only ] * * Allocates a VM map entry for insertion. * No entry fields are filled in. */ static vm_map_entry_t vm_map_entry_create(vm_map_t map) { vm_map_entry_t new_entry; if (map->system_map) new_entry = uma_zalloc(kmapentzone, M_NOWAIT); else new_entry = uma_zalloc(mapentzone, M_WAITOK); if (new_entry == NULL) panic("vm_map_entry_create: kernel resources exhausted"); return (new_entry); } /* * vm_map_entry_set_behavior: * * Set the expected access behavior, either normal, random, or * sequential. */ static inline void vm_map_entry_set_behavior(vm_map_entry_t entry, u_char behavior) { entry->eflags = (entry->eflags & ~MAP_ENTRY_BEHAV_MASK) | (behavior & MAP_ENTRY_BEHAV_MASK); } /* * vm_map_entry_set_max_free: * * Set the max_free field in a vm_map_entry. */ static inline void vm_map_entry_set_max_free(vm_map_entry_t entry) { entry->max_free = entry->adj_free; if (entry->left != NULL && entry->left->max_free > entry->max_free) entry->max_free = entry->left->max_free; if (entry->right != NULL && entry->right->max_free > entry->max_free) entry->max_free = entry->right->max_free; } /* * vm_map_entry_splay: * * The Sleator and Tarjan top-down splay algorithm with the * following variation. Max_free must be computed bottom-up, so * on the downward pass, maintain the left and right spines in * reverse order. Then, make a second pass up each side to fix * the pointers and compute max_free. The time bound is O(log n) * amortized. * * The new root is the vm_map_entry containing "addr", or else an * adjacent entry (lower or higher) if addr is not in the tree. * * The map must be locked, and leaves it so. * * Returns: the new root. */ static vm_map_entry_t vm_map_entry_splay(vm_offset_t addr, vm_map_entry_t root) { vm_map_entry_t llist, rlist; vm_map_entry_t ltree, rtree; vm_map_entry_t y; /* Special case of empty tree. */ if (root == NULL) return (root); /* * Pass One: Splay down the tree until we find addr or a NULL * pointer where addr would go. llist and rlist are the two * sides in reverse order (bottom-up), with llist linked by * the right pointer and rlist linked by the left pointer in * the vm_map_entry. Wait until Pass Two to set max_free on * the two spines. */ llist = NULL; rlist = NULL; for (;;) { /* root is never NULL in here. */ if (addr < root->start) { y = root->left; if (y == NULL) break; if (addr < y->start && y->left != NULL) { /* Rotate right and put y on rlist. */ root->left = y->right; y->right = root; vm_map_entry_set_max_free(root); root = y->left; y->left = rlist; rlist = y; } else { /* Put root on rlist. */ root->left = rlist; rlist = root; root = y; } } else if (addr >= root->end) { y = root->right; if (y == NULL) break; if (addr >= y->end && y->right != NULL) { /* Rotate left and put y on llist. */ root->right = y->left; y->left = root; vm_map_entry_set_max_free(root); root = y->right; y->right = llist; llist = y; } else { /* Put root on llist. */ root->right = llist; llist = root; root = y; } } else break; } /* * Pass Two: Walk back up the two spines, flip the pointers * and set max_free. The subtrees of the root go at the * bottom of llist and rlist. */ ltree = root->left; while (llist != NULL) { y = llist->right; llist->right = ltree; vm_map_entry_set_max_free(llist); ltree = llist; llist = y; } rtree = root->right; while (rlist != NULL) { y = rlist->left; rlist->left = rtree; vm_map_entry_set_max_free(rlist); rtree = rlist; rlist = y; } /* * Final assembly: add ltree and rtree as subtrees of root. */ root->left = ltree; root->right = rtree; vm_map_entry_set_max_free(root); return (root); } /* * vm_map_entry_{un,}link: * * Insert/remove entries from maps. */ static void vm_map_entry_link(vm_map_t map, vm_map_entry_t after_where, vm_map_entry_t entry) { CTR4(KTR_VM, "vm_map_entry_link: map %p, nentries %d, entry %p, after %p", map, map->nentries, entry, after_where); VM_MAP_ASSERT_LOCKED(map); KASSERT(after_where == &map->header || after_where->end <= entry->start, ("vm_map_entry_link: prev end %jx new start %jx overlap", (uintmax_t)after_where->end, (uintmax_t)entry->start)); KASSERT(after_where->next == &map->header || entry->end <= after_where->next->start, ("vm_map_entry_link: new end %jx next start %jx overlap", (uintmax_t)entry->end, (uintmax_t)after_where->next->start)); map->nentries++; entry->prev = after_where; entry->next = after_where->next; entry->next->prev = entry; after_where->next = entry; if (after_where != &map->header) { if (after_where != map->root) vm_map_entry_splay(after_where->start, map->root); entry->right = after_where->right; entry->left = after_where; after_where->right = NULL; after_where->adj_free = entry->start - after_where->end; vm_map_entry_set_max_free(after_where); } else { entry->right = map->root; entry->left = NULL; } entry->adj_free = (entry->next == &map->header ? map->max_offset : entry->next->start) - entry->end; vm_map_entry_set_max_free(entry); map->root = entry; } static void vm_map_entry_unlink(vm_map_t map, vm_map_entry_t entry) { vm_map_entry_t next, prev, root; VM_MAP_ASSERT_LOCKED(map); if (entry != map->root) vm_map_entry_splay(entry->start, map->root); if (entry->left == NULL) root = entry->right; else { root = vm_map_entry_splay(entry->start, entry->left); root->right = entry->right; root->adj_free = (entry->next == &map->header ? map->max_offset : entry->next->start) - root->end; vm_map_entry_set_max_free(root); } map->root = root; prev = entry->prev; next = entry->next; next->prev = prev; prev->next = next; map->nentries--; CTR3(KTR_VM, "vm_map_entry_unlink: map %p, nentries %d, entry %p", map, map->nentries, entry); } /* * vm_map_entry_resize_free: * * Recompute the amount of free space following a vm_map_entry * and propagate that value up the tree. Call this function after * resizing a map entry in-place, that is, without a call to * vm_map_entry_link() or _unlink(). * * The map must be locked, and leaves it so. */ static void vm_map_entry_resize_free(vm_map_t map, vm_map_entry_t entry) { /* * Using splay trees without parent pointers, propagating * max_free up the tree is done by moving the entry to the * root and making the change there. */ if (entry != map->root) map->root = vm_map_entry_splay(entry->start, map->root); entry->adj_free = (entry->next == &map->header ? map->max_offset : entry->next->start) - entry->end; vm_map_entry_set_max_free(entry); } /* * vm_map_lookup_entry: [ internal use only ] * * Finds the map entry containing (or * immediately preceding) the specified address * in the given map; the entry is returned * in the "entry" parameter. The boolean * result indicates whether the address is * actually contained in the map. */ boolean_t vm_map_lookup_entry( vm_map_t map, vm_offset_t address, vm_map_entry_t *entry) /* OUT */ { vm_map_entry_t cur; boolean_t locked; /* * If the map is empty, then the map entry immediately preceding * "address" is the map's header. */ cur = map->root; if (cur == NULL) *entry = &map->header; else if (address >= cur->start && cur->end > address) { *entry = cur; return (TRUE); } else if ((locked = vm_map_locked(map)) || sx_try_upgrade(&map->lock)) { /* * Splay requires a write lock on the map. However, it only * restructures the binary search tree; it does not otherwise * change the map. Thus, the map's timestamp need not change * on a temporary upgrade. */ map->root = cur = vm_map_entry_splay(address, cur); if (!locked) sx_downgrade(&map->lock); /* * If "address" is contained within a map entry, the new root * is that map entry. Otherwise, the new root is a map entry * immediately before or after "address". */ if (address >= cur->start) { *entry = cur; if (cur->end > address) return (TRUE); } else *entry = cur->prev; } else /* * Since the map is only locked for read access, perform a * standard binary search tree lookup for "address". */ for (;;) { if (address < cur->start) { if (cur->left == NULL) { *entry = cur->prev; break; } cur = cur->left; } else if (cur->end > address) { *entry = cur; return (TRUE); } else { if (cur->right == NULL) { *entry = cur; break; } cur = cur->right; } } return (FALSE); } /* * vm_map_insert: * * Inserts the given whole VM object into the target * map at the specified address range. The object's * size should match that of the address range. * * Requires that the map be locked, and leaves it so. * * If object is non-NULL, ref count must be bumped by caller * prior to making call to account for the new entry. */ int vm_map_insert(vm_map_t map, vm_object_t object, vm_ooffset_t offset, vm_offset_t start, vm_offset_t end, vm_prot_t prot, vm_prot_t max, int cow) { vm_map_entry_t new_entry, prev_entry, temp_entry; struct ucred *cred; vm_eflags_t protoeflags; vm_inherit_t inheritance; VM_MAP_ASSERT_LOCKED(map); KASSERT((object != kmem_object && object != kernel_object) || (cow & MAP_COPY_ON_WRITE) == 0, ("vm_map_insert: kmem or kernel object and COW")); KASSERT(object == NULL || (cow & MAP_NOFAULT) == 0, ("vm_map_insert: paradoxical MAP_NOFAULT request")); /* * Check that the start and end points are not bogus. */ if (start < map->min_offset || end > map->max_offset || start >= end) return (KERN_INVALID_ADDRESS); /* * Find the entry prior to the proposed starting address; if it's part * of an existing entry, this range is bogus. */ if (vm_map_lookup_entry(map, start, &temp_entry)) return (KERN_NO_SPACE); prev_entry = temp_entry; /* * Assert that the next entry doesn't overlap the end point. */ if (prev_entry->next != &map->header && prev_entry->next->start < end) return (KERN_NO_SPACE); protoeflags = 0; if (cow & MAP_COPY_ON_WRITE) protoeflags |= MAP_ENTRY_COW | MAP_ENTRY_NEEDS_COPY; if (cow & MAP_NOFAULT) protoeflags |= MAP_ENTRY_NOFAULT; if (cow & MAP_DISABLE_SYNCER) protoeflags |= MAP_ENTRY_NOSYNC; if (cow & MAP_DISABLE_COREDUMP) protoeflags |= MAP_ENTRY_NOCOREDUMP; if (cow & MAP_STACK_GROWS_DOWN) protoeflags |= MAP_ENTRY_GROWS_DOWN; if (cow & MAP_STACK_GROWS_UP) protoeflags |= MAP_ENTRY_GROWS_UP; if (cow & MAP_VN_WRITECOUNT) protoeflags |= MAP_ENTRY_VN_WRITECNT; if (cow & MAP_INHERIT_SHARE) inheritance = VM_INHERIT_SHARE; else inheritance = VM_INHERIT_DEFAULT; cred = NULL; if (cow & (MAP_ACC_NO_CHARGE | MAP_NOFAULT)) goto charged; if ((cow & MAP_ACC_CHARGED) || ((prot & VM_PROT_WRITE) && ((protoeflags & MAP_ENTRY_NEEDS_COPY) || object == NULL))) { if (!(cow & MAP_ACC_CHARGED) && !swap_reserve(end - start)) return (KERN_RESOURCE_SHORTAGE); KASSERT(object == NULL || (protoeflags & MAP_ENTRY_NEEDS_COPY) != 0 || object->cred == NULL, ("overcommit: vm_map_insert o %p", object)); cred = curthread->td_ucred; } charged: /* Expand the kernel pmap, if necessary. */ if (map == kernel_map && end > kernel_vm_end) pmap_growkernel(end); if (object != NULL) { /* * OBJ_ONEMAPPING must be cleared unless this mapping * is trivially proven to be the only mapping for any * of the object's pages. (Object granularity * reference counting is insufficient to recognize * aliases with precision.) */ VM_OBJECT_WLOCK(object); if (object->ref_count > 1 || object->shadow_count != 0) vm_object_clear_flag(object, OBJ_ONEMAPPING); VM_OBJECT_WUNLOCK(object); } else if (prev_entry != &map->header && prev_entry->eflags == protoeflags && (cow & (MAP_STACK_GROWS_DOWN | MAP_STACK_GROWS_UP)) == 0 && prev_entry->end == start && prev_entry->wired_count == 0 && (prev_entry->cred == cred || (prev_entry->object.vm_object != NULL && prev_entry->object.vm_object->cred == cred)) && vm_object_coalesce(prev_entry->object.vm_object, prev_entry->offset, (vm_size_t)(prev_entry->end - prev_entry->start), (vm_size_t)(end - prev_entry->end), cred != NULL && (protoeflags & MAP_ENTRY_NEEDS_COPY) == 0)) { /* * We were able to extend the object. Determine if we * can extend the previous map entry to include the * new range as well. */ if (prev_entry->inheritance == inheritance && prev_entry->protection == prot && prev_entry->max_protection == max) { map->size += end - prev_entry->end; prev_entry->end = end; vm_map_entry_resize_free(map, prev_entry); vm_map_simplify_entry(map, prev_entry); return (KERN_SUCCESS); } /* * If we can extend the object but cannot extend the * map entry, we have to create a new map entry. We * must bump the ref count on the extended object to * account for it. object may be NULL. */ object = prev_entry->object.vm_object; offset = prev_entry->offset + (prev_entry->end - prev_entry->start); vm_object_reference(object); if (cred != NULL && object != NULL && object->cred != NULL && !(prev_entry->eflags & MAP_ENTRY_NEEDS_COPY)) { /* Object already accounts for this uid. */ cred = NULL; } } if (cred != NULL) crhold(cred); /* * Create a new entry */ new_entry = vm_map_entry_create(map); new_entry->start = start; new_entry->end = end; new_entry->cred = NULL; new_entry->eflags = protoeflags; new_entry->object.vm_object = object; new_entry->offset = offset; new_entry->avail_ssize = 0; new_entry->inheritance = inheritance; new_entry->protection = prot; new_entry->max_protection = max; new_entry->wired_count = 0; new_entry->wiring_thread = NULL; new_entry->read_ahead = VM_FAULT_READ_AHEAD_INIT; new_entry->next_read = start; KASSERT(cred == NULL || !ENTRY_CHARGED(new_entry), ("overcommit: vm_map_insert leaks vm_map %p", new_entry)); new_entry->cred = cred; /* * Insert the new entry into the list */ vm_map_entry_link(map, prev_entry, new_entry); map->size += new_entry->end - new_entry->start; /* * Try to coalesce the new entry with both the previous and next * entries in the list. Previously, we only attempted to coalesce * with the previous entry when object is NULL. Here, we handle the * other cases, which are less common. */ vm_map_simplify_entry(map, new_entry); if ((cow & (MAP_PREFAULT | MAP_PREFAULT_PARTIAL)) != 0) { vm_map_pmap_enter(map, start, prot, object, OFF_TO_IDX(offset), end - start, cow & MAP_PREFAULT_PARTIAL); } return (KERN_SUCCESS); } /* * vm_map_findspace: * * Find the first fit (lowest VM address) for "length" free bytes * beginning at address >= start in the given map. * * In a vm_map_entry, "adj_free" is the amount of free space * adjacent (higher address) to this entry, and "max_free" is the * maximum amount of contiguous free space in its subtree. This * allows finding a free region in one path down the tree, so * O(log n) amortized with splay trees. * * The map must be locked, and leaves it so. * * Returns: 0 on success, and starting address in *addr, * 1 if insufficient space. */ int vm_map_findspace(vm_map_t map, vm_offset_t start, vm_size_t length, vm_offset_t *addr) /* OUT */ { vm_map_entry_t entry; vm_offset_t st; /* * Request must fit within min/max VM address and must avoid * address wrap. */ if (start < map->min_offset) start = map->min_offset; if (start + length > map->max_offset || start + length < start) return (1); /* Empty tree means wide open address space. */ if (map->root == NULL) { *addr = start; return (0); } /* * After splay, if start comes before root node, then there * must be a gap from start to the root. */ map->root = vm_map_entry_splay(start, map->root); if (start + length <= map->root->start) { *addr = start; return (0); } /* * Root is the last node that might begin its gap before * start, and this is the last comparison where address * wrap might be a problem. */ st = (start > map->root->end) ? start : map->root->end; if (length <= map->root->end + map->root->adj_free - st) { *addr = st; return (0); } /* With max_free, can immediately tell if no solution. */ entry = map->root->right; if (entry == NULL || length > entry->max_free) return (1); /* * Search the right subtree in the order: left subtree, root, * right subtree (first fit). The previous splay implies that * all regions in the right subtree have addresses > start. */ while (entry != NULL) { if (entry->left != NULL && entry->left->max_free >= length) entry = entry->left; else if (entry->adj_free >= length) { *addr = entry->end; return (0); } else entry = entry->right; } /* Can't get here, so panic if we do. */ panic("vm_map_findspace: max_free corrupt"); } int vm_map_fixed(vm_map_t map, vm_object_t object, vm_ooffset_t offset, vm_offset_t start, vm_size_t length, vm_prot_t prot, vm_prot_t max, int cow) { vm_offset_t end; int result; end = start + length; KASSERT((cow & (MAP_STACK_GROWS_DOWN | MAP_STACK_GROWS_UP)) == 0 || object == NULL, ("vm_map_fixed: non-NULL backing object for stack")); vm_map_lock(map); VM_MAP_RANGE_CHECK(map, start, end); if ((cow & MAP_CHECK_EXCL) == 0) vm_map_delete(map, start, end); if ((cow & (MAP_STACK_GROWS_DOWN | MAP_STACK_GROWS_UP)) != 0) { result = vm_map_stack_locked(map, start, length, sgrowsiz, prot, max, cow); } else { result = vm_map_insert(map, object, offset, start, end, prot, max, cow); } vm_map_unlock(map); return (result); } /* * vm_map_find finds an unallocated region in the target address * map with the given length. The search is defined to be * first-fit from the specified address; the region found is * returned in the same parameter. * * If object is non-NULL, ref count must be bumped by caller * prior to making call to account for the new entry. */ int vm_map_find(vm_map_t map, vm_object_t object, vm_ooffset_t offset, vm_offset_t *addr, /* IN/OUT */ vm_size_t length, vm_offset_t max_addr, int find_space, vm_prot_t prot, vm_prot_t max, int cow) { vm_offset_t alignment, initial_addr, start; int result; KASSERT((cow & (MAP_STACK_GROWS_DOWN | MAP_STACK_GROWS_UP)) == 0 || object == NULL, ("vm_map_find: non-NULL backing object for stack")); if (find_space == VMFS_OPTIMAL_SPACE && (object == NULL || (object->flags & OBJ_COLORED) == 0)) find_space = VMFS_ANY_SPACE; if (find_space >> 8 != 0) { KASSERT((find_space & 0xff) == 0, ("bad VMFS flags")); alignment = (vm_offset_t)1 << (find_space >> 8); } else alignment = 0; initial_addr = *addr; again: start = initial_addr; vm_map_lock(map); do { if (find_space != VMFS_NO_SPACE) { if (vm_map_findspace(map, start, length, addr) || (max_addr != 0 && *addr + length > max_addr)) { vm_map_unlock(map); if (find_space == VMFS_OPTIMAL_SPACE) { find_space = VMFS_ANY_SPACE; goto again; } return (KERN_NO_SPACE); } switch (find_space) { case VMFS_SUPER_SPACE: case VMFS_OPTIMAL_SPACE: pmap_align_superpage(object, offset, addr, length); break; case VMFS_ANY_SPACE: break; default: if ((*addr & (alignment - 1)) != 0) { *addr &= ~(alignment - 1); *addr += alignment; } break; } start = *addr; } if ((cow & (MAP_STACK_GROWS_DOWN | MAP_STACK_GROWS_UP)) != 0) { result = vm_map_stack_locked(map, start, length, sgrowsiz, prot, max, cow); } else { result = vm_map_insert(map, object, offset, start, start + length, prot, max, cow); } } while (result == KERN_NO_SPACE && find_space != VMFS_NO_SPACE && find_space != VMFS_ANY_SPACE); vm_map_unlock(map); return (result); } /* * vm_map_simplify_entry: * * Simplify the given map entry by merging with either neighbor. This * routine also has the ability to merge with both neighbors. * * The map must be locked. * * This routine guarantees that the passed entry remains valid (though * possibly extended). When merging, this routine may delete one or * both neighbors. */ void vm_map_simplify_entry(vm_map_t map, vm_map_entry_t entry) { vm_map_entry_t next, prev; vm_size_t prevsize, esize; if ((entry->eflags & (MAP_ENTRY_GROWS_DOWN | MAP_ENTRY_GROWS_UP | MAP_ENTRY_IN_TRANSITION | MAP_ENTRY_IS_SUB_MAP)) != 0) return; prev = entry->prev; if (prev != &map->header) { prevsize = prev->end - prev->start; if ( (prev->end == entry->start) && (prev->object.vm_object == entry->object.vm_object) && (!prev->object.vm_object || (prev->offset + prevsize == entry->offset)) && (prev->eflags == entry->eflags) && (prev->protection == entry->protection) && (prev->max_protection == entry->max_protection) && (prev->inheritance == entry->inheritance) && (prev->wired_count == entry->wired_count) && (prev->cred == entry->cred)) { vm_map_entry_unlink(map, prev); entry->start = prev->start; entry->offset = prev->offset; if (entry->prev != &map->header) vm_map_entry_resize_free(map, entry->prev); /* * If the backing object is a vnode object, * vm_object_deallocate() calls vrele(). * However, vrele() does not lock the vnode * because the vnode has additional * references. Thus, the map lock can be kept * without causing a lock-order reversal with * the vnode lock. * * Since we count the number of virtual page * mappings in object->un_pager.vnp.writemappings, * the writemappings value should not be adjusted * when the entry is disposed of. */ if (prev->object.vm_object) vm_object_deallocate(prev->object.vm_object); if (prev->cred != NULL) crfree(prev->cred); vm_map_entry_dispose(map, prev); } } next = entry->next; if (next != &map->header) { esize = entry->end - entry->start; if ((entry->end == next->start) && (next->object.vm_object == entry->object.vm_object) && (!entry->object.vm_object || (entry->offset + esize == next->offset)) && (next->eflags == entry->eflags) && (next->protection == entry->protection) && (next->max_protection == entry->max_protection) && (next->inheritance == entry->inheritance) && (next->wired_count == entry->wired_count) && (next->cred == entry->cred)) { vm_map_entry_unlink(map, next); entry->end = next->end; vm_map_entry_resize_free(map, entry); /* * See comment above. */ if (next->object.vm_object) vm_object_deallocate(next->object.vm_object); if (next->cred != NULL) crfree(next->cred); vm_map_entry_dispose(map, next); } } } /* * vm_map_clip_start: [ internal use only ] * * Asserts that the given entry begins at or after * the specified address; if necessary, * it splits the entry into two. */ #define vm_map_clip_start(map, entry, startaddr) \ { \ if (startaddr > entry->start) \ _vm_map_clip_start(map, entry, startaddr); \ } /* * This routine is called only when it is known that * the entry must be split. */ static void _vm_map_clip_start(vm_map_t map, vm_map_entry_t entry, vm_offset_t start) { vm_map_entry_t new_entry; VM_MAP_ASSERT_LOCKED(map); KASSERT(entry->end > start && entry->start < start, ("_vm_map_clip_start: invalid clip of entry %p", entry)); /* * Split off the front portion -- note that we must insert the new * entry BEFORE this one, so that this entry has the specified * starting address. */ vm_map_simplify_entry(map, entry); /* * If there is no object backing this entry, we might as well create * one now. If we defer it, an object can get created after the map * is clipped, and individual objects will be created for the split-up * map. This is a bit of a hack, but is also about the best place to * put this improvement. */ if (entry->object.vm_object == NULL && !map->system_map) { vm_object_t object; object = vm_object_allocate(OBJT_DEFAULT, atop(entry->end - entry->start)); entry->object.vm_object = object; entry->offset = 0; if (entry->cred != NULL) { object->cred = entry->cred; object->charge = entry->end - entry->start; entry->cred = NULL; } } else if (entry->object.vm_object != NULL && ((entry->eflags & MAP_ENTRY_NEEDS_COPY) == 0) && entry->cred != NULL) { VM_OBJECT_WLOCK(entry->object.vm_object); KASSERT(entry->object.vm_object->cred == NULL, ("OVERCOMMIT: vm_entry_clip_start: both cred e %p", entry)); entry->object.vm_object->cred = entry->cred; entry->object.vm_object->charge = entry->end - entry->start; VM_OBJECT_WUNLOCK(entry->object.vm_object); entry->cred = NULL; } new_entry = vm_map_entry_create(map); *new_entry = *entry; new_entry->end = start; entry->offset += (start - entry->start); entry->start = start; if (new_entry->cred != NULL) crhold(entry->cred); vm_map_entry_link(map, entry->prev, new_entry); if ((entry->eflags & MAP_ENTRY_IS_SUB_MAP) == 0) { vm_object_reference(new_entry->object.vm_object); /* * The object->un_pager.vnp.writemappings for the * object of MAP_ENTRY_VN_WRITECNT type entry shall be * kept as is here. The virtual pages are * re-distributed among the clipped entries, so the sum is * left the same. */ } } /* * vm_map_clip_end: [ internal use only ] * * Asserts that the given entry ends at or before * the specified address; if necessary, * it splits the entry into two. */ #define vm_map_clip_end(map, entry, endaddr) \ { \ if ((endaddr) < (entry->end)) \ _vm_map_clip_end((map), (entry), (endaddr)); \ } /* * This routine is called only when it is known that * the entry must be split. */ static void _vm_map_clip_end(vm_map_t map, vm_map_entry_t entry, vm_offset_t end) { vm_map_entry_t new_entry; VM_MAP_ASSERT_LOCKED(map); KASSERT(entry->start < end && entry->end > end, ("_vm_map_clip_end: invalid clip of entry %p", entry)); /* * If there is no object backing this entry, we might as well create * one now. If we defer it, an object can get created after the map * is clipped, and individual objects will be created for the split-up * map. This is a bit of a hack, but is also about the best place to * put this improvement. */ if (entry->object.vm_object == NULL && !map->system_map) { vm_object_t object; object = vm_object_allocate(OBJT_DEFAULT, atop(entry->end - entry->start)); entry->object.vm_object = object; entry->offset = 0; if (entry->cred != NULL) { object->cred = entry->cred; object->charge = entry->end - entry->start; entry->cred = NULL; } } else if (entry->object.vm_object != NULL && ((entry->eflags & MAP_ENTRY_NEEDS_COPY) == 0) && entry->cred != NULL) { VM_OBJECT_WLOCK(entry->object.vm_object); KASSERT(entry->object.vm_object->cred == NULL, ("OVERCOMMIT: vm_entry_clip_end: both cred e %p", entry)); entry->object.vm_object->cred = entry->cred; entry->object.vm_object->charge = entry->end - entry->start; VM_OBJECT_WUNLOCK(entry->object.vm_object); entry->cred = NULL; } /* * Create a new entry and insert it AFTER the specified entry */ new_entry = vm_map_entry_create(map); *new_entry = *entry; new_entry->start = entry->end = end; new_entry->offset += (end - entry->start); if (new_entry->cred != NULL) crhold(entry->cred); vm_map_entry_link(map, entry, new_entry); if ((entry->eflags & MAP_ENTRY_IS_SUB_MAP) == 0) { vm_object_reference(new_entry->object.vm_object); } } /* * vm_map_submap: [ kernel use only ] * * Mark the given range as handled by a subordinate map. * * This range must have been created with vm_map_find, * and no other operations may have been performed on this * range prior to calling vm_map_submap. * * Only a limited number of operations can be performed * within this rage after calling vm_map_submap: * vm_fault * [Don't try vm_map_copy!] * * To remove a submapping, one must first remove the * range from the superior map, and then destroy the * submap (if desired). [Better yet, don't try it.] */ int vm_map_submap( vm_map_t map, vm_offset_t start, vm_offset_t end, vm_map_t submap) { vm_map_entry_t entry; int result = KERN_INVALID_ARGUMENT; vm_map_lock(map); VM_MAP_RANGE_CHECK(map, start, end); if (vm_map_lookup_entry(map, start, &entry)) { vm_map_clip_start(map, entry, start); } else entry = entry->next; vm_map_clip_end(map, entry, end); if ((entry->start == start) && (entry->end == end) && ((entry->eflags & MAP_ENTRY_COW) == 0) && (entry->object.vm_object == NULL)) { entry->object.sub_map = submap; entry->eflags |= MAP_ENTRY_IS_SUB_MAP; result = KERN_SUCCESS; } vm_map_unlock(map); return (result); } /* * The maximum number of pages to map if MAP_PREFAULT_PARTIAL is specified */ #define MAX_INIT_PT 96 /* * vm_map_pmap_enter: * * Preload the specified map's pmap with mappings to the specified * object's memory-resident pages. No further physical pages are * allocated, and no further virtual pages are retrieved from secondary * storage. If the specified flags include MAP_PREFAULT_PARTIAL, then a * limited number of page mappings are created at the low-end of the * specified address range. (For this purpose, a superpage mapping * counts as one page mapping.) Otherwise, all resident pages within * the specified address range are mapped. */ static void vm_map_pmap_enter(vm_map_t map, vm_offset_t addr, vm_prot_t prot, vm_object_t object, vm_pindex_t pindex, vm_size_t size, int flags) { vm_offset_t start; vm_page_t p, p_start; vm_pindex_t mask, psize, threshold, tmpidx; if ((prot & (VM_PROT_READ | VM_PROT_EXECUTE)) == 0 || object == NULL) return; VM_OBJECT_RLOCK(object); if (object->type == OBJT_DEVICE || object->type == OBJT_SG) { VM_OBJECT_RUNLOCK(object); VM_OBJECT_WLOCK(object); if (object->type == OBJT_DEVICE || object->type == OBJT_SG) { pmap_object_init_pt(map->pmap, addr, object, pindex, size); VM_OBJECT_WUNLOCK(object); return; } VM_OBJECT_LOCK_DOWNGRADE(object); } psize = atop(size); if (psize + pindex > object->size) { if (object->size < pindex) { VM_OBJECT_RUNLOCK(object); return; } psize = object->size - pindex; } start = 0; p_start = NULL; threshold = MAX_INIT_PT; p = vm_page_find_least(object, pindex); /* * Assert: the variable p is either (1) the page with the * least pindex greater than or equal to the parameter pindex * or (2) NULL. */ for (; p != NULL && (tmpidx = p->pindex - pindex) < psize; p = TAILQ_NEXT(p, listq)) { /* * don't allow an madvise to blow away our really * free pages allocating pv entries. */ if (((flags & MAP_PREFAULT_MADVISE) != 0 && vm_cnt.v_free_count < vm_cnt.v_free_reserved) || ((flags & MAP_PREFAULT_PARTIAL) != 0 && tmpidx >= threshold)) { psize = tmpidx; break; } if (p->valid == VM_PAGE_BITS_ALL) { if (p_start == NULL) { start = addr + ptoa(tmpidx); p_start = p; } /* Jump ahead if a superpage mapping is possible. */ if (p->psind > 0 && ((addr + ptoa(tmpidx)) & (pagesizes[p->psind] - 1)) == 0) { mask = atop(pagesizes[p->psind]) - 1; if (tmpidx + mask < psize && vm_page_ps_is_valid(p)) { p += mask; threshold += mask; } } } else if (p_start != NULL) { pmap_enter_object(map->pmap, start, addr + ptoa(tmpidx), p_start, prot); p_start = NULL; } } if (p_start != NULL) pmap_enter_object(map->pmap, start, addr + ptoa(psize), p_start, prot); VM_OBJECT_RUNLOCK(object); } /* * vm_map_protect: * * Sets the protection of the specified address * region in the target map. If "set_max" is * specified, the maximum protection is to be set; * otherwise, only the current protection is affected. */ int vm_map_protect(vm_map_t map, vm_offset_t start, vm_offset_t end, vm_prot_t new_prot, boolean_t set_max) { vm_map_entry_t current, entry; vm_object_t obj; struct ucred *cred; vm_prot_t old_prot; if (start == end) return (KERN_SUCCESS); vm_map_lock(map); /* * Ensure that we are not concurrently wiring pages. vm_map_wire() may * need to fault pages into the map and will drop the map lock while * doing so, and the VM object may end up in an inconsistent state if we * update the protection on the map entry in between faults. */ vm_map_wait_busy(map); VM_MAP_RANGE_CHECK(map, start, end); if (vm_map_lookup_entry(map, start, &entry)) { vm_map_clip_start(map, entry, start); } else { entry = entry->next; } /* * Make a first pass to check for protection violations. */ for (current = entry; current != &map->header && current->start < end; current = current->next) { if (current->eflags & MAP_ENTRY_IS_SUB_MAP) { vm_map_unlock(map); return (KERN_INVALID_ARGUMENT); } if ((new_prot & current->max_protection) != new_prot) { vm_map_unlock(map); return (KERN_PROTECTION_FAILURE); } } /* * Do an accounting pass for private read-only mappings that * now will do cow due to allowed write (e.g. debugger sets * breakpoint on text segment) */ for (current = entry; current != &map->header && current->start < end; current = current->next) { vm_map_clip_end(map, current, end); if (set_max || ((new_prot & ~(current->protection)) & VM_PROT_WRITE) == 0 || ENTRY_CHARGED(current)) { continue; } cred = curthread->td_ucred; obj = current->object.vm_object; if (obj == NULL || (current->eflags & MAP_ENTRY_NEEDS_COPY)) { if (!swap_reserve(current->end - current->start)) { vm_map_unlock(map); return (KERN_RESOURCE_SHORTAGE); } crhold(cred); current->cred = cred; continue; } VM_OBJECT_WLOCK(obj); if (obj->type != OBJT_DEFAULT && obj->type != OBJT_SWAP) { VM_OBJECT_WUNLOCK(obj); continue; } /* * Charge for the whole object allocation now, since * we cannot distinguish between non-charged and * charged clipped mapping of the same object later. */ KASSERT(obj->charge == 0, ("vm_map_protect: object %p overcharged (entry %p)", obj, current)); if (!swap_reserve(ptoa(obj->size))) { VM_OBJECT_WUNLOCK(obj); vm_map_unlock(map); return (KERN_RESOURCE_SHORTAGE); } crhold(cred); obj->cred = cred; obj->charge = ptoa(obj->size); VM_OBJECT_WUNLOCK(obj); } /* * Go back and fix up protections. [Note that clipping is not * necessary the second time.] */ for (current = entry; current != &map->header && current->start < end; current = current->next) { old_prot = current->protection; if (set_max) current->protection = (current->max_protection = new_prot) & old_prot; else current->protection = new_prot; /* * For user wired map entries, the normal lazy evaluation of * write access upgrades through soft page faults is * undesirable. Instead, immediately copy any pages that are * copy-on-write and enable write access in the physical map. */ if ((current->eflags & MAP_ENTRY_USER_WIRED) != 0 && (current->protection & VM_PROT_WRITE) != 0 && (old_prot & VM_PROT_WRITE) == 0) vm_fault_copy_entry(map, map, current, current, NULL); /* * When restricting access, update the physical map. Worry * about copy-on-write here. */ if ((old_prot & ~current->protection) != 0) { #define MASK(entry) (((entry)->eflags & MAP_ENTRY_COW) ? ~VM_PROT_WRITE : \ VM_PROT_ALL) pmap_protect(map->pmap, current->start, current->end, current->protection & MASK(current)); #undef MASK } vm_map_simplify_entry(map, current); } vm_map_unlock(map); return (KERN_SUCCESS); } /* * vm_map_madvise: * * This routine traverses a processes map handling the madvise * system call. Advisories are classified as either those effecting * the vm_map_entry structure, or those effecting the underlying * objects. */ int vm_map_madvise( vm_map_t map, vm_offset_t start, vm_offset_t end, int behav) { vm_map_entry_t current, entry; int modify_map = 0; /* * Some madvise calls directly modify the vm_map_entry, in which case * we need to use an exclusive lock on the map and we need to perform * various clipping operations. Otherwise we only need a read-lock * on the map. */ switch(behav) { case MADV_NORMAL: case MADV_SEQUENTIAL: case MADV_RANDOM: case MADV_NOSYNC: case MADV_AUTOSYNC: case MADV_NOCORE: case MADV_CORE: if (start == end) return (KERN_SUCCESS); modify_map = 1; vm_map_lock(map); break; case MADV_WILLNEED: case MADV_DONTNEED: case MADV_FREE: if (start == end) return (KERN_SUCCESS); vm_map_lock_read(map); break; default: return (KERN_INVALID_ARGUMENT); } /* * Locate starting entry and clip if necessary. */ VM_MAP_RANGE_CHECK(map, start, end); if (vm_map_lookup_entry(map, start, &entry)) { if (modify_map) vm_map_clip_start(map, entry, start); } else { entry = entry->next; } if (modify_map) { /* * madvise behaviors that are implemented in the vm_map_entry. * * We clip the vm_map_entry so that behavioral changes are * limited to the specified address range. */ for (current = entry; (current != &map->header) && (current->start < end); current = current->next ) { if (current->eflags & MAP_ENTRY_IS_SUB_MAP) continue; vm_map_clip_end(map, current, end); switch (behav) { case MADV_NORMAL: vm_map_entry_set_behavior(current, MAP_ENTRY_BEHAV_NORMAL); break; case MADV_SEQUENTIAL: vm_map_entry_set_behavior(current, MAP_ENTRY_BEHAV_SEQUENTIAL); break; case MADV_RANDOM: vm_map_entry_set_behavior(current, MAP_ENTRY_BEHAV_RANDOM); break; case MADV_NOSYNC: current->eflags |= MAP_ENTRY_NOSYNC; break; case MADV_AUTOSYNC: current->eflags &= ~MAP_ENTRY_NOSYNC; break; case MADV_NOCORE: current->eflags |= MAP_ENTRY_NOCOREDUMP; break; case MADV_CORE: current->eflags &= ~MAP_ENTRY_NOCOREDUMP; break; default: break; } vm_map_simplify_entry(map, current); } vm_map_unlock(map); } else { vm_pindex_t pstart, pend; /* * madvise behaviors that are implemented in the underlying * vm_object. * * Since we don't clip the vm_map_entry, we have to clip * the vm_object pindex and count. */ for (current = entry; (current != &map->header) && (current->start < end); current = current->next ) { vm_offset_t useEnd, useStart; if (current->eflags & MAP_ENTRY_IS_SUB_MAP) continue; pstart = OFF_TO_IDX(current->offset); pend = pstart + atop(current->end - current->start); useStart = current->start; useEnd = current->end; if (current->start < start) { pstart += atop(start - current->start); useStart = start; } if (current->end > end) { pend -= atop(current->end - end); useEnd = end; } if (pstart >= pend) continue; /* * Perform the pmap_advise() before clearing * PGA_REFERENCED in vm_page_advise(). Otherwise, a * concurrent pmap operation, such as pmap_remove(), * could clear a reference in the pmap and set * PGA_REFERENCED on the page before the pmap_advise() * had completed. Consequently, the page would appear * referenced based upon an old reference that * occurred before this pmap_advise() ran. */ if (behav == MADV_DONTNEED || behav == MADV_FREE) pmap_advise(map->pmap, useStart, useEnd, behav); vm_object_madvise(current->object.vm_object, pstart, pend, behav); /* * Pre-populate paging structures in the * WILLNEED case. For wired entries, the * paging structures are already populated. */ if (behav == MADV_WILLNEED && current->wired_count == 0) { vm_map_pmap_enter(map, useStart, current->protection, current->object.vm_object, pstart, ptoa(pend - pstart), MAP_PREFAULT_MADVISE ); } } vm_map_unlock_read(map); } return (0); } /* * vm_map_inherit: * * Sets the inheritance of the specified address * range in the target map. Inheritance * affects how the map will be shared with * child maps at the time of vmspace_fork. */ int vm_map_inherit(vm_map_t map, vm_offset_t start, vm_offset_t end, vm_inherit_t new_inheritance) { vm_map_entry_t entry; vm_map_entry_t temp_entry; switch (new_inheritance) { case VM_INHERIT_NONE: case VM_INHERIT_COPY: case VM_INHERIT_SHARE: + case VM_INHERIT_ZERO: break; default: return (KERN_INVALID_ARGUMENT); } if (start == end) return (KERN_SUCCESS); vm_map_lock(map); VM_MAP_RANGE_CHECK(map, start, end); if (vm_map_lookup_entry(map, start, &temp_entry)) { entry = temp_entry; vm_map_clip_start(map, entry, start); } else entry = temp_entry->next; while ((entry != &map->header) && (entry->start < end)) { vm_map_clip_end(map, entry, end); entry->inheritance = new_inheritance; vm_map_simplify_entry(map, entry); entry = entry->next; } vm_map_unlock(map); return (KERN_SUCCESS); } /* * vm_map_unwire: * * Implements both kernel and user unwiring. */ int vm_map_unwire(vm_map_t map, vm_offset_t start, vm_offset_t end, int flags) { vm_map_entry_t entry, first_entry, tmp_entry; vm_offset_t saved_start; unsigned int last_timestamp; int rv; boolean_t need_wakeup, result, user_unwire; if (start == end) return (KERN_SUCCESS); user_unwire = (flags & VM_MAP_WIRE_USER) ? TRUE : FALSE; vm_map_lock(map); VM_MAP_RANGE_CHECK(map, start, end); if (!vm_map_lookup_entry(map, start, &first_entry)) { if (flags & VM_MAP_WIRE_HOLESOK) first_entry = first_entry->next; else { vm_map_unlock(map); return (KERN_INVALID_ADDRESS); } } last_timestamp = map->timestamp; entry = first_entry; while (entry != &map->header && entry->start < end) { if (entry->eflags & MAP_ENTRY_IN_TRANSITION) { /* * We have not yet clipped the entry. */ saved_start = (start >= entry->start) ? start : entry->start; entry->eflags |= MAP_ENTRY_NEEDS_WAKEUP; if (vm_map_unlock_and_wait(map, 0)) { /* * Allow interruption of user unwiring? */ } vm_map_lock(map); if (last_timestamp+1 != map->timestamp) { /* * Look again for the entry because the map was * modified while it was unlocked. * Specifically, the entry may have been * clipped, merged, or deleted. */ if (!vm_map_lookup_entry(map, saved_start, &tmp_entry)) { if (flags & VM_MAP_WIRE_HOLESOK) tmp_entry = tmp_entry->next; else { if (saved_start == start) { /* * First_entry has been deleted. */ vm_map_unlock(map); return (KERN_INVALID_ADDRESS); } end = saved_start; rv = KERN_INVALID_ADDRESS; goto done; } } if (entry == first_entry) first_entry = tmp_entry; else first_entry = NULL; entry = tmp_entry; } last_timestamp = map->timestamp; continue; } vm_map_clip_start(map, entry, start); vm_map_clip_end(map, entry, end); /* * Mark the entry in case the map lock is released. (See * above.) */ KASSERT((entry->eflags & MAP_ENTRY_IN_TRANSITION) == 0 && entry->wiring_thread == NULL, ("owned map entry %p", entry)); entry->eflags |= MAP_ENTRY_IN_TRANSITION; entry->wiring_thread = curthread; /* * Check the map for holes in the specified region. * If VM_MAP_WIRE_HOLESOK was specified, skip this check. */ if (((flags & VM_MAP_WIRE_HOLESOK) == 0) && (entry->end < end && (entry->next == &map->header || entry->next->start > entry->end))) { end = entry->end; rv = KERN_INVALID_ADDRESS; goto done; } /* * If system unwiring, require that the entry is system wired. */ if (!user_unwire && vm_map_entry_system_wired_count(entry) == 0) { end = entry->end; rv = KERN_INVALID_ARGUMENT; goto done; } entry = entry->next; } rv = KERN_SUCCESS; done: need_wakeup = FALSE; if (first_entry == NULL) { result = vm_map_lookup_entry(map, start, &first_entry); if (!result && (flags & VM_MAP_WIRE_HOLESOK)) first_entry = first_entry->next; else KASSERT(result, ("vm_map_unwire: lookup failed")); } for (entry = first_entry; entry != &map->header && entry->start < end; entry = entry->next) { /* * If VM_MAP_WIRE_HOLESOK was specified, an empty * space in the unwired region could have been mapped * while the map lock was dropped for draining * MAP_ENTRY_IN_TRANSITION. Moreover, another thread * could be simultaneously wiring this new mapping * entry. Detect these cases and skip any entries * marked as in transition by us. */ if ((entry->eflags & MAP_ENTRY_IN_TRANSITION) == 0 || entry->wiring_thread != curthread) { KASSERT((flags & VM_MAP_WIRE_HOLESOK) != 0, ("vm_map_unwire: !HOLESOK and new/changed entry")); continue; } if (rv == KERN_SUCCESS && (!user_unwire || (entry->eflags & MAP_ENTRY_USER_WIRED))) { if (user_unwire) entry->eflags &= ~MAP_ENTRY_USER_WIRED; if (entry->wired_count == 1) vm_map_entry_unwire(map, entry); else entry->wired_count--; } KASSERT((entry->eflags & MAP_ENTRY_IN_TRANSITION) != 0, ("vm_map_unwire: in-transition flag missing %p", entry)); KASSERT(entry->wiring_thread == curthread, ("vm_map_unwire: alien wire %p", entry)); entry->eflags &= ~MAP_ENTRY_IN_TRANSITION; entry->wiring_thread = NULL; if (entry->eflags & MAP_ENTRY_NEEDS_WAKEUP) { entry->eflags &= ~MAP_ENTRY_NEEDS_WAKEUP; need_wakeup = TRUE; } vm_map_simplify_entry(map, entry); } vm_map_unlock(map); if (need_wakeup) vm_map_wakeup(map); return (rv); } /* * vm_map_wire_entry_failure: * * Handle a wiring failure on the given entry. * * The map should be locked. */ static void vm_map_wire_entry_failure(vm_map_t map, vm_map_entry_t entry, vm_offset_t failed_addr) { VM_MAP_ASSERT_LOCKED(map); KASSERT((entry->eflags & MAP_ENTRY_IN_TRANSITION) != 0 && entry->wired_count == 1, ("vm_map_wire_entry_failure: entry %p isn't being wired", entry)); KASSERT(failed_addr < entry->end, ("vm_map_wire_entry_failure: entry %p was fully wired", entry)); /* * If any pages at the start of this entry were successfully wired, * then unwire them. */ if (failed_addr > entry->start) { pmap_unwire(map->pmap, entry->start, failed_addr); vm_object_unwire(entry->object.vm_object, entry->offset, failed_addr - entry->start, PQ_ACTIVE); } /* * Assign an out-of-range value to represent the failure to wire this * entry. */ entry->wired_count = -1; } /* * vm_map_wire: * * Implements both kernel and user wiring. */ int vm_map_wire(vm_map_t map, vm_offset_t start, vm_offset_t end, int flags) { vm_map_entry_t entry, first_entry, tmp_entry; vm_offset_t faddr, saved_end, saved_start; unsigned int last_timestamp; int rv; boolean_t need_wakeup, result, user_wire; vm_prot_t prot; if (start == end) return (KERN_SUCCESS); prot = 0; if (flags & VM_MAP_WIRE_WRITE) prot |= VM_PROT_WRITE; user_wire = (flags & VM_MAP_WIRE_USER) ? TRUE : FALSE; vm_map_lock(map); VM_MAP_RANGE_CHECK(map, start, end); if (!vm_map_lookup_entry(map, start, &first_entry)) { if (flags & VM_MAP_WIRE_HOLESOK) first_entry = first_entry->next; else { vm_map_unlock(map); return (KERN_INVALID_ADDRESS); } } last_timestamp = map->timestamp; entry = first_entry; while (entry != &map->header && entry->start < end) { if (entry->eflags & MAP_ENTRY_IN_TRANSITION) { /* * We have not yet clipped the entry. */ saved_start = (start >= entry->start) ? start : entry->start; entry->eflags |= MAP_ENTRY_NEEDS_WAKEUP; if (vm_map_unlock_and_wait(map, 0)) { /* * Allow interruption of user wiring? */ } vm_map_lock(map); if (last_timestamp + 1 != map->timestamp) { /* * Look again for the entry because the map was * modified while it was unlocked. * Specifically, the entry may have been * clipped, merged, or deleted. */ if (!vm_map_lookup_entry(map, saved_start, &tmp_entry)) { if (flags & VM_MAP_WIRE_HOLESOK) tmp_entry = tmp_entry->next; else { if (saved_start == start) { /* * first_entry has been deleted. */ vm_map_unlock(map); return (KERN_INVALID_ADDRESS); } end = saved_start; rv = KERN_INVALID_ADDRESS; goto done; } } if (entry == first_entry) first_entry = tmp_entry; else first_entry = NULL; entry = tmp_entry; } last_timestamp = map->timestamp; continue; } vm_map_clip_start(map, entry, start); vm_map_clip_end(map, entry, end); /* * Mark the entry in case the map lock is released. (See * above.) */ KASSERT((entry->eflags & MAP_ENTRY_IN_TRANSITION) == 0 && entry->wiring_thread == NULL, ("owned map entry %p", entry)); entry->eflags |= MAP_ENTRY_IN_TRANSITION; entry->wiring_thread = curthread; if ((entry->protection & (VM_PROT_READ | VM_PROT_EXECUTE)) == 0 || (entry->protection & prot) != prot) { entry->eflags |= MAP_ENTRY_WIRE_SKIPPED; if ((flags & VM_MAP_WIRE_HOLESOK) == 0) { end = entry->end; rv = KERN_INVALID_ADDRESS; goto done; } goto next_entry; } if (entry->wired_count == 0) { entry->wired_count++; saved_start = entry->start; saved_end = entry->end; /* * Release the map lock, relying on the in-transition * mark. Mark the map busy for fork. */ vm_map_busy(map); vm_map_unlock(map); faddr = saved_start; do { /* * Simulate a fault to get the page and enter * it into the physical map. */ if ((rv = vm_fault(map, faddr, VM_PROT_NONE, VM_FAULT_WIRE)) != KERN_SUCCESS) break; } while ((faddr += PAGE_SIZE) < saved_end); vm_map_lock(map); vm_map_unbusy(map); if (last_timestamp + 1 != map->timestamp) { /* * Look again for the entry because the map was * modified while it was unlocked. The entry * may have been clipped, but NOT merged or * deleted. */ result = vm_map_lookup_entry(map, saved_start, &tmp_entry); KASSERT(result, ("vm_map_wire: lookup failed")); if (entry == first_entry) first_entry = tmp_entry; else first_entry = NULL; entry = tmp_entry; while (entry->end < saved_end) { /* * In case of failure, handle entries * that were not fully wired here; * fully wired entries are handled * later. */ if (rv != KERN_SUCCESS && faddr < entry->end) vm_map_wire_entry_failure(map, entry, faddr); entry = entry->next; } } last_timestamp = map->timestamp; if (rv != KERN_SUCCESS) { vm_map_wire_entry_failure(map, entry, faddr); end = entry->end; goto done; } } else if (!user_wire || (entry->eflags & MAP_ENTRY_USER_WIRED) == 0) { entry->wired_count++; } /* * Check the map for holes in the specified region. * If VM_MAP_WIRE_HOLESOK was specified, skip this check. */ next_entry: if (((flags & VM_MAP_WIRE_HOLESOK) == 0) && (entry->end < end && (entry->next == &map->header || entry->next->start > entry->end))) { end = entry->end; rv = KERN_INVALID_ADDRESS; goto done; } entry = entry->next; } rv = KERN_SUCCESS; done: need_wakeup = FALSE; if (first_entry == NULL) { result = vm_map_lookup_entry(map, start, &first_entry); if (!result && (flags & VM_MAP_WIRE_HOLESOK)) first_entry = first_entry->next; else KASSERT(result, ("vm_map_wire: lookup failed")); } for (entry = first_entry; entry != &map->header && entry->start < end; entry = entry->next) { if ((entry->eflags & MAP_ENTRY_WIRE_SKIPPED) != 0) goto next_entry_done; /* * If VM_MAP_WIRE_HOLESOK was specified, an empty * space in the unwired region could have been mapped * while the map lock was dropped for faulting in the * pages or draining MAP_ENTRY_IN_TRANSITION. * Moreover, another thread could be simultaneously * wiring this new mapping entry. Detect these cases * and skip any entries marked as in transition by us. */ if ((entry->eflags & MAP_ENTRY_IN_TRANSITION) == 0 || entry->wiring_thread != curthread) { KASSERT((flags & VM_MAP_WIRE_HOLESOK) != 0, ("vm_map_wire: !HOLESOK and new/changed entry")); continue; } if (rv == KERN_SUCCESS) { if (user_wire) entry->eflags |= MAP_ENTRY_USER_WIRED; } else if (entry->wired_count == -1) { /* * Wiring failed on this entry. Thus, unwiring is * unnecessary. */ entry->wired_count = 0; } else if (!user_wire || (entry->eflags & MAP_ENTRY_USER_WIRED) == 0) { /* * Undo the wiring. Wiring succeeded on this entry * but failed on a later entry. */ if (entry->wired_count == 1) vm_map_entry_unwire(map, entry); else entry->wired_count--; } next_entry_done: KASSERT((entry->eflags & MAP_ENTRY_IN_TRANSITION) != 0, ("vm_map_wire: in-transition flag missing %p", entry)); KASSERT(entry->wiring_thread == curthread, ("vm_map_wire: alien wire %p", entry)); entry->eflags &= ~(MAP_ENTRY_IN_TRANSITION | MAP_ENTRY_WIRE_SKIPPED); entry->wiring_thread = NULL; if (entry->eflags & MAP_ENTRY_NEEDS_WAKEUP) { entry->eflags &= ~MAP_ENTRY_NEEDS_WAKEUP; need_wakeup = TRUE; } vm_map_simplify_entry(map, entry); } vm_map_unlock(map); if (need_wakeup) vm_map_wakeup(map); return (rv); } /* * vm_map_sync * * Push any dirty cached pages in the address range to their pager. * If syncio is TRUE, dirty pages are written synchronously. * If invalidate is TRUE, any cached pages are freed as well. * * If the size of the region from start to end is zero, we are * supposed to flush all modified pages within the region containing * start. Unfortunately, a region can be split or coalesced with * neighboring regions, making it difficult to determine what the * original region was. Therefore, we approximate this requirement by * flushing the current region containing start. * * Returns an error if any part of the specified range is not mapped. */ int vm_map_sync( vm_map_t map, vm_offset_t start, vm_offset_t end, boolean_t syncio, boolean_t invalidate) { vm_map_entry_t current; vm_map_entry_t entry; vm_size_t size; vm_object_t object; vm_ooffset_t offset; unsigned int last_timestamp; boolean_t failed; vm_map_lock_read(map); VM_MAP_RANGE_CHECK(map, start, end); if (!vm_map_lookup_entry(map, start, &entry)) { vm_map_unlock_read(map); return (KERN_INVALID_ADDRESS); } else if (start == end) { start = entry->start; end = entry->end; } /* * Make a first pass to check for user-wired memory and holes. */ for (current = entry; current != &map->header && current->start < end; current = current->next) { if (invalidate && (current->eflags & MAP_ENTRY_USER_WIRED)) { vm_map_unlock_read(map); return (KERN_INVALID_ARGUMENT); } if (end > current->end && (current->next == &map->header || current->end != current->next->start)) { vm_map_unlock_read(map); return (KERN_INVALID_ADDRESS); } } if (invalidate) pmap_remove(map->pmap, start, end); failed = FALSE; /* * Make a second pass, cleaning/uncaching pages from the indicated * objects as we go. */ for (current = entry; current != &map->header && current->start < end;) { offset = current->offset + (start - current->start); size = (end <= current->end ? end : current->end) - start; if (current->eflags & MAP_ENTRY_IS_SUB_MAP) { vm_map_t smap; vm_map_entry_t tentry; vm_size_t tsize; smap = current->object.sub_map; vm_map_lock_read(smap); (void) vm_map_lookup_entry(smap, offset, &tentry); tsize = tentry->end - offset; if (tsize < size) size = tsize; object = tentry->object.vm_object; offset = tentry->offset + (offset - tentry->start); vm_map_unlock_read(smap); } else { object = current->object.vm_object; } vm_object_reference(object); last_timestamp = map->timestamp; vm_map_unlock_read(map); if (!vm_object_sync(object, offset, size, syncio, invalidate)) failed = TRUE; start += size; vm_object_deallocate(object); vm_map_lock_read(map); if (last_timestamp == map->timestamp || !vm_map_lookup_entry(map, start, ¤t)) current = current->next; } vm_map_unlock_read(map); return (failed ? KERN_FAILURE : KERN_SUCCESS); } /* * vm_map_entry_unwire: [ internal use only ] * * Make the region specified by this entry pageable. * * The map in question should be locked. * [This is the reason for this routine's existence.] */ static void vm_map_entry_unwire(vm_map_t map, vm_map_entry_t entry) { VM_MAP_ASSERT_LOCKED(map); KASSERT(entry->wired_count > 0, ("vm_map_entry_unwire: entry %p isn't wired", entry)); pmap_unwire(map->pmap, entry->start, entry->end); vm_object_unwire(entry->object.vm_object, entry->offset, entry->end - entry->start, PQ_ACTIVE); entry->wired_count = 0; } static void vm_map_entry_deallocate(vm_map_entry_t entry, boolean_t system_map) { if ((entry->eflags & MAP_ENTRY_IS_SUB_MAP) == 0) vm_object_deallocate(entry->object.vm_object); uma_zfree(system_map ? kmapentzone : mapentzone, entry); } /* * vm_map_entry_delete: [ internal use only ] * * Deallocate the given entry from the target map. */ static void vm_map_entry_delete(vm_map_t map, vm_map_entry_t entry) { vm_object_t object; vm_pindex_t offidxstart, offidxend, count, size1; vm_size_t size; vm_map_entry_unlink(map, entry); object = entry->object.vm_object; size = entry->end - entry->start; map->size -= size; if (entry->cred != NULL) { swap_release_by_cred(size, entry->cred); crfree(entry->cred); } if ((entry->eflags & MAP_ENTRY_IS_SUB_MAP) == 0 && (object != NULL)) { KASSERT(entry->cred == NULL || object->cred == NULL || (entry->eflags & MAP_ENTRY_NEEDS_COPY), ("OVERCOMMIT vm_map_entry_delete: both cred %p", entry)); count = atop(size); offidxstart = OFF_TO_IDX(entry->offset); offidxend = offidxstart + count; VM_OBJECT_WLOCK(object); if (object->ref_count != 1 && ((object->flags & (OBJ_NOSPLIT | OBJ_ONEMAPPING)) == OBJ_ONEMAPPING || object == kernel_object || object == kmem_object)) { vm_object_collapse(object); /* * The option OBJPR_NOTMAPPED can be passed here * because vm_map_delete() already performed * pmap_remove() on the only mapping to this range * of pages. */ vm_object_page_remove(object, offidxstart, offidxend, OBJPR_NOTMAPPED); if (object->type == OBJT_SWAP) swap_pager_freespace(object, offidxstart, count); if (offidxend >= object->size && offidxstart < object->size) { size1 = object->size; object->size = offidxstart; if (object->cred != NULL) { size1 -= object->size; KASSERT(object->charge >= ptoa(size1), ("object %p charge < 0", object)); swap_release_by_cred(ptoa(size1), object->cred); object->charge -= ptoa(size1); } } } VM_OBJECT_WUNLOCK(object); } else entry->object.vm_object = NULL; if (map->system_map) vm_map_entry_deallocate(entry, TRUE); else { entry->next = curthread->td_map_def_user; curthread->td_map_def_user = entry; } } /* * vm_map_delete: [ internal use only ] * * Deallocates the given address range from the target * map. */ int vm_map_delete(vm_map_t map, vm_offset_t start, vm_offset_t end) { vm_map_entry_t entry; vm_map_entry_t first_entry; VM_MAP_ASSERT_LOCKED(map); if (start == end) return (KERN_SUCCESS); /* * Find the start of the region, and clip it */ if (!vm_map_lookup_entry(map, start, &first_entry)) entry = first_entry->next; else { entry = first_entry; vm_map_clip_start(map, entry, start); } /* * Step through all entries in this region */ while ((entry != &map->header) && (entry->start < end)) { vm_map_entry_t next; /* * Wait for wiring or unwiring of an entry to complete. * Also wait for any system wirings to disappear on * user maps. */ if ((entry->eflags & MAP_ENTRY_IN_TRANSITION) != 0 || (vm_map_pmap(map) != kernel_pmap && vm_map_entry_system_wired_count(entry) != 0)) { unsigned int last_timestamp; vm_offset_t saved_start; vm_map_entry_t tmp_entry; saved_start = entry->start; entry->eflags |= MAP_ENTRY_NEEDS_WAKEUP; last_timestamp = map->timestamp; (void) vm_map_unlock_and_wait(map, 0); vm_map_lock(map); if (last_timestamp + 1 != map->timestamp) { /* * Look again for the entry because the map was * modified while it was unlocked. * Specifically, the entry may have been * clipped, merged, or deleted. */ if (!vm_map_lookup_entry(map, saved_start, &tmp_entry)) entry = tmp_entry->next; else { entry = tmp_entry; vm_map_clip_start(map, entry, saved_start); } } continue; } vm_map_clip_end(map, entry, end); next = entry->next; /* * Unwire before removing addresses from the pmap; otherwise, * unwiring will put the entries back in the pmap. */ if (entry->wired_count != 0) { vm_map_entry_unwire(map, entry); } pmap_remove(map->pmap, entry->start, entry->end); /* * Delete the entry only after removing all pmap * entries pointing to its pages. (Otherwise, its * page frames may be reallocated, and any modify bits * will be set in the wrong object!) */ vm_map_entry_delete(map, entry); entry = next; } return (KERN_SUCCESS); } /* * vm_map_remove: * * Remove the given address range from the target map. * This is the exported form of vm_map_delete. */ int vm_map_remove(vm_map_t map, vm_offset_t start, vm_offset_t end) { int result; vm_map_lock(map); VM_MAP_RANGE_CHECK(map, start, end); result = vm_map_delete(map, start, end); vm_map_unlock(map); return (result); } /* * vm_map_check_protection: * * Assert that the target map allows the specified privilege on the * entire address region given. The entire region must be allocated. * * WARNING! This code does not and should not check whether the * contents of the region is accessible. For example a smaller file * might be mapped into a larger address space. * * NOTE! This code is also called by munmap(). * * The map must be locked. A read lock is sufficient. */ boolean_t vm_map_check_protection(vm_map_t map, vm_offset_t start, vm_offset_t end, vm_prot_t protection) { vm_map_entry_t entry; vm_map_entry_t tmp_entry; if (!vm_map_lookup_entry(map, start, &tmp_entry)) return (FALSE); entry = tmp_entry; while (start < end) { if (entry == &map->header) return (FALSE); /* * No holes allowed! */ if (start < entry->start) return (FALSE); /* * Check protection associated with entry. */ if ((entry->protection & protection) != protection) return (FALSE); /* go to next entry */ start = entry->end; entry = entry->next; } return (TRUE); } /* * vm_map_copy_entry: * * Copies the contents of the source entry to the destination * entry. The entries *must* be aligned properly. */ static void vm_map_copy_entry( vm_map_t src_map, vm_map_t dst_map, vm_map_entry_t src_entry, vm_map_entry_t dst_entry, vm_ooffset_t *fork_charge) { vm_object_t src_object; vm_map_entry_t fake_entry; vm_offset_t size; struct ucred *cred; int charged; VM_MAP_ASSERT_LOCKED(dst_map); if ((dst_entry->eflags|src_entry->eflags) & MAP_ENTRY_IS_SUB_MAP) return; if (src_entry->wired_count == 0 || (src_entry->protection & VM_PROT_WRITE) == 0) { /* * If the source entry is marked needs_copy, it is already * write-protected. */ if ((src_entry->eflags & MAP_ENTRY_NEEDS_COPY) == 0 && (src_entry->protection & VM_PROT_WRITE) != 0) { pmap_protect(src_map->pmap, src_entry->start, src_entry->end, src_entry->protection & ~VM_PROT_WRITE); } /* * Make a copy of the object. */ size = src_entry->end - src_entry->start; if ((src_object = src_entry->object.vm_object) != NULL) { VM_OBJECT_WLOCK(src_object); charged = ENTRY_CHARGED(src_entry); if (src_object->handle == NULL && (src_object->type == OBJT_DEFAULT || src_object->type == OBJT_SWAP)) { vm_object_collapse(src_object); if ((src_object->flags & (OBJ_NOSPLIT | OBJ_ONEMAPPING)) == OBJ_ONEMAPPING) { vm_object_split(src_entry); src_object = src_entry->object.vm_object; } } vm_object_reference_locked(src_object); vm_object_clear_flag(src_object, OBJ_ONEMAPPING); if (src_entry->cred != NULL && !(src_entry->eflags & MAP_ENTRY_NEEDS_COPY)) { KASSERT(src_object->cred == NULL, ("OVERCOMMIT: vm_map_copy_entry: cred %p", src_object)); src_object->cred = src_entry->cred; src_object->charge = size; } VM_OBJECT_WUNLOCK(src_object); dst_entry->object.vm_object = src_object; if (charged) { cred = curthread->td_ucred; crhold(cred); dst_entry->cred = cred; *fork_charge += size; if (!(src_entry->eflags & MAP_ENTRY_NEEDS_COPY)) { crhold(cred); src_entry->cred = cred; *fork_charge += size; } } src_entry->eflags |= MAP_ENTRY_COW | MAP_ENTRY_NEEDS_COPY; dst_entry->eflags |= MAP_ENTRY_COW | MAP_ENTRY_NEEDS_COPY; dst_entry->offset = src_entry->offset; if (src_entry->eflags & MAP_ENTRY_VN_WRITECNT) { /* * MAP_ENTRY_VN_WRITECNT cannot * indicate write reference from * src_entry, since the entry is * marked as needs copy. Allocate a * fake entry that is used to * decrement object->un_pager.vnp.writecount * at the appropriate time. Attach * fake_entry to the deferred list. */ fake_entry = vm_map_entry_create(dst_map); fake_entry->eflags = MAP_ENTRY_VN_WRITECNT; src_entry->eflags &= ~MAP_ENTRY_VN_WRITECNT; vm_object_reference(src_object); fake_entry->object.vm_object = src_object; fake_entry->start = src_entry->start; fake_entry->end = src_entry->end; fake_entry->next = curthread->td_map_def_user; curthread->td_map_def_user = fake_entry; } } else { dst_entry->object.vm_object = NULL; dst_entry->offset = 0; if (src_entry->cred != NULL) { dst_entry->cred = curthread->td_ucred; crhold(dst_entry->cred); *fork_charge += size; } } pmap_copy(dst_map->pmap, src_map->pmap, dst_entry->start, dst_entry->end - dst_entry->start, src_entry->start); } else { /* * We don't want to make writeable wired pages copy-on-write. * Immediately copy these pages into the new map by simulating * page faults. The new pages are pageable. */ vm_fault_copy_entry(dst_map, src_map, dst_entry, src_entry, fork_charge); } } /* * vmspace_map_entry_forked: * Update the newly-forked vmspace each time a map entry is inherited * or copied. The values for vm_dsize and vm_tsize are approximate * (and mostly-obsolete ideas in the face of mmap(2) et al.) */ static void vmspace_map_entry_forked(const struct vmspace *vm1, struct vmspace *vm2, vm_map_entry_t entry) { vm_size_t entrysize; vm_offset_t newend; entrysize = entry->end - entry->start; vm2->vm_map.size += entrysize; if (entry->eflags & (MAP_ENTRY_GROWS_DOWN | MAP_ENTRY_GROWS_UP)) { vm2->vm_ssize += btoc(entrysize); } else if (entry->start >= (vm_offset_t)vm1->vm_daddr && entry->start < (vm_offset_t)vm1->vm_daddr + ctob(vm1->vm_dsize)) { newend = MIN(entry->end, (vm_offset_t)vm1->vm_daddr + ctob(vm1->vm_dsize)); vm2->vm_dsize += btoc(newend - entry->start); } else if (entry->start >= (vm_offset_t)vm1->vm_taddr && entry->start < (vm_offset_t)vm1->vm_taddr + ctob(vm1->vm_tsize)) { newend = MIN(entry->end, (vm_offset_t)vm1->vm_taddr + ctob(vm1->vm_tsize)); vm2->vm_tsize += btoc(newend - entry->start); } } /* * vmspace_fork: * Create a new process vmspace structure and vm_map * based on those of an existing process. The new map * is based on the old map, according to the inheritance * values on the regions in that map. * * XXX It might be worth coalescing the entries added to the new vmspace. * * The source map must not be locked. */ struct vmspace * vmspace_fork(struct vmspace *vm1, vm_ooffset_t *fork_charge) { struct vmspace *vm2; vm_map_t new_map, old_map; vm_map_entry_t new_entry, old_entry; vm_object_t object; int locked; old_map = &vm1->vm_map; /* Copy immutable fields of vm1 to vm2. */ vm2 = vmspace_alloc(old_map->min_offset, old_map->max_offset, NULL); if (vm2 == NULL) return (NULL); vm2->vm_taddr = vm1->vm_taddr; vm2->vm_daddr = vm1->vm_daddr; vm2->vm_maxsaddr = vm1->vm_maxsaddr; vm_map_lock(old_map); if (old_map->busy) vm_map_wait_busy(old_map); new_map = &vm2->vm_map; locked = vm_map_trylock(new_map); /* trylock to silence WITNESS */ KASSERT(locked, ("vmspace_fork: lock failed")); old_entry = old_map->header.next; while (old_entry != &old_map->header) { if (old_entry->eflags & MAP_ENTRY_IS_SUB_MAP) panic("vm_map_fork: encountered a submap"); switch (old_entry->inheritance) { case VM_INHERIT_NONE: break; case VM_INHERIT_SHARE: /* * Clone the entry, creating the shared object if necessary. */ object = old_entry->object.vm_object; if (object == NULL) { object = vm_object_allocate(OBJT_DEFAULT, atop(old_entry->end - old_entry->start)); old_entry->object.vm_object = object; old_entry->offset = 0; if (old_entry->cred != NULL) { object->cred = old_entry->cred; object->charge = old_entry->end - old_entry->start; old_entry->cred = NULL; } } /* * Add the reference before calling vm_object_shadow * to insure that a shadow object is created. */ vm_object_reference(object); if (old_entry->eflags & MAP_ENTRY_NEEDS_COPY) { vm_object_shadow(&old_entry->object.vm_object, &old_entry->offset, old_entry->end - old_entry->start); old_entry->eflags &= ~MAP_ENTRY_NEEDS_COPY; /* Transfer the second reference too. */ vm_object_reference( old_entry->object.vm_object); /* * As in vm_map_simplify_entry(), the * vnode lock will not be acquired in * this call to vm_object_deallocate(). */ vm_object_deallocate(object); object = old_entry->object.vm_object; } VM_OBJECT_WLOCK(object); vm_object_clear_flag(object, OBJ_ONEMAPPING); if (old_entry->cred != NULL) { KASSERT(object->cred == NULL, ("vmspace_fork both cred")); object->cred = old_entry->cred; object->charge = old_entry->end - old_entry->start; old_entry->cred = NULL; } /* * Assert the correct state of the vnode * v_writecount while the object is locked, to * not relock it later for the assertion * correctness. */ if (old_entry->eflags & MAP_ENTRY_VN_WRITECNT && object->type == OBJT_VNODE) { KASSERT(((struct vnode *)object->handle)-> v_writecount > 0, ("vmspace_fork: v_writecount %p", object)); KASSERT(object->un_pager.vnp.writemappings > 0, ("vmspace_fork: vnp.writecount %p", object)); } VM_OBJECT_WUNLOCK(object); /* * Clone the entry, referencing the shared object. */ new_entry = vm_map_entry_create(new_map); *new_entry = *old_entry; new_entry->eflags &= ~(MAP_ENTRY_USER_WIRED | MAP_ENTRY_IN_TRANSITION); new_entry->wiring_thread = NULL; new_entry->wired_count = 0; if (new_entry->eflags & MAP_ENTRY_VN_WRITECNT) { vnode_pager_update_writecount(object, new_entry->start, new_entry->end); } /* * Insert the entry into the new map -- we know we're * inserting at the end of the new map. */ vm_map_entry_link(new_map, new_map->header.prev, new_entry); vmspace_map_entry_forked(vm1, vm2, new_entry); /* * Update the physical map */ pmap_copy(new_map->pmap, old_map->pmap, new_entry->start, (old_entry->end - old_entry->start), old_entry->start); break; case VM_INHERIT_COPY: /* * Clone the entry and link into the map. */ new_entry = vm_map_entry_create(new_map); *new_entry = *old_entry; /* * Copied entry is COW over the old object. */ new_entry->eflags &= ~(MAP_ENTRY_USER_WIRED | MAP_ENTRY_IN_TRANSITION | MAP_ENTRY_VN_WRITECNT); new_entry->wiring_thread = NULL; new_entry->wired_count = 0; new_entry->object.vm_object = NULL; new_entry->cred = NULL; vm_map_entry_link(new_map, new_map->header.prev, new_entry); vmspace_map_entry_forked(vm1, vm2, new_entry); vm_map_copy_entry(old_map, new_map, old_entry, new_entry, fork_charge); + break; + + case VM_INHERIT_ZERO: + /* + * Create a new anonymous mapping entry modelled from + * the old one. + */ + new_entry = vm_map_entry_create(new_map); + memset(new_entry, 0, sizeof(*new_entry)); + + new_entry->start = old_entry->start; + new_entry->end = old_entry->end; + new_entry->avail_ssize = old_entry->avail_ssize; + new_entry->eflags = old_entry->eflags & + ~(MAP_ENTRY_USER_WIRED | MAP_ENTRY_IN_TRANSITION | + MAP_ENTRY_VN_WRITECNT); + new_entry->protection = old_entry->protection; + new_entry->max_protection = old_entry->max_protection; + new_entry->inheritance = VM_INHERIT_ZERO; + + vm_map_entry_link(new_map, new_map->header.prev, + new_entry); + vmspace_map_entry_forked(vm1, vm2, new_entry); + + new_entry->cred = curthread->td_ucred; + crhold(new_entry->cred); + *fork_charge += (new_entry->end - new_entry->start); + break; } old_entry = old_entry->next; } /* * Use inlined vm_map_unlock() to postpone handling the deferred * map entries, which cannot be done until both old_map and * new_map locks are released. */ sx_xunlock(&old_map->lock); sx_xunlock(&new_map->lock); vm_map_process_deferred(); return (vm2); } int vm_map_stack(vm_map_t map, vm_offset_t addrbos, vm_size_t max_ssize, vm_prot_t prot, vm_prot_t max, int cow) { vm_size_t growsize, init_ssize; rlim_t lmemlim, vmemlim; int rv; growsize = sgrowsiz; init_ssize = (max_ssize < growsize) ? max_ssize : growsize; vm_map_lock(map); lmemlim = lim_cur(curthread, RLIMIT_MEMLOCK); vmemlim = lim_cur(curthread, RLIMIT_VMEM); if (!old_mlock && map->flags & MAP_WIREFUTURE) { if (ptoa(pmap_wired_count(map->pmap)) + init_ssize > lmemlim) { rv = KERN_NO_SPACE; goto out; } } /* If we would blow our VMEM resource limit, no go */ if (map->size + init_ssize > vmemlim) { rv = KERN_NO_SPACE; goto out; } rv = vm_map_stack_locked(map, addrbos, max_ssize, growsize, prot, max, cow); out: vm_map_unlock(map); return (rv); } static int vm_map_stack_locked(vm_map_t map, vm_offset_t addrbos, vm_size_t max_ssize, vm_size_t growsize, vm_prot_t prot, vm_prot_t max, int cow) { vm_map_entry_t new_entry, prev_entry; vm_offset_t bot, top; vm_size_t init_ssize; int orient, rv; /* * The stack orientation is piggybacked with the cow argument. * Extract it into orient and mask the cow argument so that we * don't pass it around further. * NOTE: We explicitly allow bi-directional stacks. */ orient = cow & (MAP_STACK_GROWS_DOWN|MAP_STACK_GROWS_UP); KASSERT(orient != 0, ("No stack grow direction")); if (addrbos < vm_map_min(map) || addrbos > vm_map_max(map) || addrbos + max_ssize < addrbos) return (KERN_NO_SPACE); init_ssize = (max_ssize < growsize) ? max_ssize : growsize; /* If addr is already mapped, no go */ if (vm_map_lookup_entry(map, addrbos, &prev_entry)) return (KERN_NO_SPACE); /* * If we can't accommodate max_ssize in the current mapping, no go. * However, we need to be aware that subsequent user mappings might * map into the space we have reserved for stack, and currently this * space is not protected. * * Hopefully we will at least detect this condition when we try to * grow the stack. */ if ((prev_entry->next != &map->header) && (prev_entry->next->start < addrbos + max_ssize)) return (KERN_NO_SPACE); /* * We initially map a stack of only init_ssize. We will grow as * needed later. Depending on the orientation of the stack (i.e. * the grow direction) we either map at the top of the range, the * bottom of the range or in the middle. * * Note: we would normally expect prot and max to be VM_PROT_ALL, * and cow to be 0. Possibly we should eliminate these as input * parameters, and just pass these values here in the insert call. */ if (orient == MAP_STACK_GROWS_DOWN) bot = addrbos + max_ssize - init_ssize; else if (orient == MAP_STACK_GROWS_UP) bot = addrbos; else bot = round_page(addrbos + max_ssize/2 - init_ssize/2); top = bot + init_ssize; rv = vm_map_insert(map, NULL, 0, bot, top, prot, max, cow); /* Now set the avail_ssize amount. */ if (rv == KERN_SUCCESS) { new_entry = prev_entry->next; if (new_entry->end != top || new_entry->start != bot) panic("Bad entry start/end for new stack entry"); new_entry->avail_ssize = max_ssize - init_ssize; KASSERT((orient & MAP_STACK_GROWS_DOWN) == 0 || (new_entry->eflags & MAP_ENTRY_GROWS_DOWN) != 0, ("new entry lacks MAP_ENTRY_GROWS_DOWN")); KASSERT((orient & MAP_STACK_GROWS_UP) == 0 || (new_entry->eflags & MAP_ENTRY_GROWS_UP) != 0, ("new entry lacks MAP_ENTRY_GROWS_UP")); } return (rv); } static int stack_guard_page = 0; SYSCTL_INT(_security_bsd, OID_AUTO, stack_guard_page, CTLFLAG_RWTUN, &stack_guard_page, 0, "Insert stack guard page ahead of the growable segments."); /* Attempts to grow a vm stack entry. Returns KERN_SUCCESS if the * desired address is already mapped, or if we successfully grow * the stack. Also returns KERN_SUCCESS if addr is outside the * stack range (this is strange, but preserves compatibility with * the grow function in vm_machdep.c). */ int vm_map_growstack(struct proc *p, vm_offset_t addr) { vm_map_entry_t next_entry, prev_entry; vm_map_entry_t new_entry, stack_entry; struct vmspace *vm = p->p_vmspace; vm_map_t map = &vm->vm_map; vm_offset_t end; vm_size_t growsize; size_t grow_amount, max_grow; rlim_t lmemlim, stacklim, vmemlim; int is_procstack, rv; struct ucred *cred; #ifdef notyet uint64_t limit; #endif #ifdef RACCT int error; #endif lmemlim = lim_cur(curthread, RLIMIT_MEMLOCK); stacklim = lim_cur(curthread, RLIMIT_STACK); vmemlim = lim_cur(curthread, RLIMIT_VMEM); Retry: vm_map_lock_read(map); /* If addr is already in the entry range, no need to grow.*/ if (vm_map_lookup_entry(map, addr, &prev_entry)) { vm_map_unlock_read(map); return (KERN_SUCCESS); } next_entry = prev_entry->next; if (!(prev_entry->eflags & MAP_ENTRY_GROWS_UP)) { /* * This entry does not grow upwards. Since the address lies * beyond this entry, the next entry (if one exists) has to * be a downward growable entry. The entry list header is * never a growable entry, so it suffices to check the flags. */ if (!(next_entry->eflags & MAP_ENTRY_GROWS_DOWN)) { vm_map_unlock_read(map); return (KERN_SUCCESS); } stack_entry = next_entry; } else { /* * This entry grows upward. If the next entry does not at * least grow downwards, this is the entry we need to grow. * otherwise we have two possible choices and we have to * select one. */ if (next_entry->eflags & MAP_ENTRY_GROWS_DOWN) { /* * We have two choices; grow the entry closest to * the address to minimize the amount of growth. */ if (addr - prev_entry->end <= next_entry->start - addr) stack_entry = prev_entry; else stack_entry = next_entry; } else stack_entry = prev_entry; } if (stack_entry == next_entry) { KASSERT(stack_entry->eflags & MAP_ENTRY_GROWS_DOWN, ("foo")); KASSERT(addr < stack_entry->start, ("foo")); end = (prev_entry != &map->header) ? prev_entry->end : stack_entry->start - stack_entry->avail_ssize; grow_amount = roundup(stack_entry->start - addr, PAGE_SIZE); max_grow = stack_entry->start - end; } else { KASSERT(stack_entry->eflags & MAP_ENTRY_GROWS_UP, ("foo")); KASSERT(addr >= stack_entry->end, ("foo")); end = (next_entry != &map->header) ? next_entry->start : stack_entry->end + stack_entry->avail_ssize; grow_amount = roundup(addr + 1 - stack_entry->end, PAGE_SIZE); max_grow = end - stack_entry->end; } if (grow_amount > stack_entry->avail_ssize) { vm_map_unlock_read(map); return (KERN_NO_SPACE); } /* * If there is no longer enough space between the entries nogo, and * adjust the available space. Note: this should only happen if the * user has mapped into the stack area after the stack was created, * and is probably an error. * * This also effectively destroys any guard page the user might have * intended by limiting the stack size. */ if (grow_amount + (stack_guard_page ? PAGE_SIZE : 0) > max_grow) { if (vm_map_lock_upgrade(map)) goto Retry; stack_entry->avail_ssize = max_grow; vm_map_unlock(map); return (KERN_NO_SPACE); } is_procstack = (addr >= (vm_offset_t)vm->vm_maxsaddr && addr < (vm_offset_t)p->p_sysent->sv_usrstack) ? 1 : 0; /* * If this is the main process stack, see if we're over the stack * limit. */ if (is_procstack && (ctob(vm->vm_ssize) + grow_amount > stacklim)) { vm_map_unlock_read(map); return (KERN_NO_SPACE); } #ifdef RACCT if (racct_enable) { PROC_LOCK(p); if (is_procstack && racct_set(p, RACCT_STACK, ctob(vm->vm_ssize) + grow_amount)) { PROC_UNLOCK(p); vm_map_unlock_read(map); return (KERN_NO_SPACE); } PROC_UNLOCK(p); } #endif /* Round up the grow amount modulo sgrowsiz */ growsize = sgrowsiz; grow_amount = roundup(grow_amount, growsize); if (grow_amount > stack_entry->avail_ssize) grow_amount = stack_entry->avail_ssize; if (is_procstack && (ctob(vm->vm_ssize) + grow_amount > stacklim)) { grow_amount = trunc_page((vm_size_t)stacklim) - ctob(vm->vm_ssize); } #ifdef notyet PROC_LOCK(p); limit = racct_get_available(p, RACCT_STACK); PROC_UNLOCK(p); if (is_procstack && (ctob(vm->vm_ssize) + grow_amount > limit)) grow_amount = limit - ctob(vm->vm_ssize); #endif if (!old_mlock && map->flags & MAP_WIREFUTURE) { if (ptoa(pmap_wired_count(map->pmap)) + grow_amount > lmemlim) { vm_map_unlock_read(map); rv = KERN_NO_SPACE; goto out; } #ifdef RACCT if (racct_enable) { PROC_LOCK(p); if (racct_set(p, RACCT_MEMLOCK, ptoa(pmap_wired_count(map->pmap)) + grow_amount)) { PROC_UNLOCK(p); vm_map_unlock_read(map); rv = KERN_NO_SPACE; goto out; } PROC_UNLOCK(p); } #endif } /* If we would blow our VMEM resource limit, no go */ if (map->size + grow_amount > vmemlim) { vm_map_unlock_read(map); rv = KERN_NO_SPACE; goto out; } #ifdef RACCT if (racct_enable) { PROC_LOCK(p); if (racct_set(p, RACCT_VMEM, map->size + grow_amount)) { PROC_UNLOCK(p); vm_map_unlock_read(map); rv = KERN_NO_SPACE; goto out; } PROC_UNLOCK(p); } #endif if (vm_map_lock_upgrade(map)) goto Retry; if (stack_entry == next_entry) { /* * Growing downward. */ /* Get the preliminary new entry start value */ addr = stack_entry->start - grow_amount; /* * If this puts us into the previous entry, cut back our * growth to the available space. Also, see the note above. */ if (addr < end) { stack_entry->avail_ssize = max_grow; addr = end; if (stack_guard_page) addr += PAGE_SIZE; } rv = vm_map_insert(map, NULL, 0, addr, stack_entry->start, next_entry->protection, next_entry->max_protection, MAP_STACK_GROWS_DOWN); /* Adjust the available stack space by the amount we grew. */ if (rv == KERN_SUCCESS) { new_entry = prev_entry->next; KASSERT(new_entry == stack_entry->prev, ("foo")); KASSERT(new_entry->end == stack_entry->start, ("foo")); KASSERT(new_entry->start == addr, ("foo")); KASSERT((new_entry->eflags & MAP_ENTRY_GROWS_DOWN) != 0, ("new entry lacks MAP_ENTRY_GROWS_DOWN")); grow_amount = new_entry->end - new_entry->start; new_entry->avail_ssize = stack_entry->avail_ssize - grow_amount; stack_entry->eflags &= ~MAP_ENTRY_GROWS_DOWN; } } else { /* * Growing upward. */ addr = stack_entry->end + grow_amount; /* * If this puts us into the next entry, cut back our growth * to the available space. Also, see the note above. */ if (addr > end) { stack_entry->avail_ssize = end - stack_entry->end; addr = end; if (stack_guard_page) addr -= PAGE_SIZE; } grow_amount = addr - stack_entry->end; cred = stack_entry->cred; if (cred == NULL && stack_entry->object.vm_object != NULL) cred = stack_entry->object.vm_object->cred; if (cred != NULL && !swap_reserve_by_cred(grow_amount, cred)) rv = KERN_NO_SPACE; /* Grow the underlying object if applicable. */ else if (stack_entry->object.vm_object == NULL || vm_object_coalesce(stack_entry->object.vm_object, stack_entry->offset, (vm_size_t)(stack_entry->end - stack_entry->start), (vm_size_t)grow_amount, cred != NULL)) { map->size += (addr - stack_entry->end); /* Update the current entry. */ stack_entry->end = addr; stack_entry->avail_ssize -= grow_amount; vm_map_entry_resize_free(map, stack_entry); rv = KERN_SUCCESS; } else rv = KERN_FAILURE; } if (rv == KERN_SUCCESS && is_procstack) vm->vm_ssize += btoc(grow_amount); vm_map_unlock(map); /* * Heed the MAP_WIREFUTURE flag if it was set for this process. */ if (rv == KERN_SUCCESS && (map->flags & MAP_WIREFUTURE)) { vm_map_wire(map, (stack_entry == next_entry) ? addr : addr - grow_amount, (stack_entry == next_entry) ? stack_entry->start : addr, (p->p_flag & P_SYSTEM) ? VM_MAP_WIRE_SYSTEM|VM_MAP_WIRE_NOHOLES : VM_MAP_WIRE_USER|VM_MAP_WIRE_NOHOLES); } out: #ifdef RACCT if (racct_enable && rv != KERN_SUCCESS) { PROC_LOCK(p); error = racct_set(p, RACCT_VMEM, map->size); KASSERT(error == 0, ("decreasing RACCT_VMEM failed")); if (!old_mlock) { error = racct_set(p, RACCT_MEMLOCK, ptoa(pmap_wired_count(map->pmap))); KASSERT(error == 0, ("decreasing RACCT_MEMLOCK failed")); } error = racct_set(p, RACCT_STACK, ctob(vm->vm_ssize)); KASSERT(error == 0, ("decreasing RACCT_STACK failed")); PROC_UNLOCK(p); } #endif return (rv); } /* * Unshare the specified VM space for exec. If other processes are * mapped to it, then create a new one. The new vmspace is null. */ int vmspace_exec(struct proc *p, vm_offset_t minuser, vm_offset_t maxuser) { struct vmspace *oldvmspace = p->p_vmspace; struct vmspace *newvmspace; KASSERT((curthread->td_pflags & TDP_EXECVMSPC) == 0, ("vmspace_exec recursed")); newvmspace = vmspace_alloc(minuser, maxuser, NULL); if (newvmspace == NULL) return (ENOMEM); newvmspace->vm_swrss = oldvmspace->vm_swrss; /* * This code is written like this for prototype purposes. The * goal is to avoid running down the vmspace here, but let the * other process's that are still using the vmspace to finally * run it down. Even though there is little or no chance of blocking * here, it is a good idea to keep this form for future mods. */ PROC_VMSPACE_LOCK(p); p->p_vmspace = newvmspace; PROC_VMSPACE_UNLOCK(p); if (p == curthread->td_proc) pmap_activate(curthread); curthread->td_pflags |= TDP_EXECVMSPC; return (0); } /* * Unshare the specified VM space for forcing COW. This * is called by rfork, for the (RFMEM|RFPROC) == 0 case. */ int vmspace_unshare(struct proc *p) { struct vmspace *oldvmspace = p->p_vmspace; struct vmspace *newvmspace; vm_ooffset_t fork_charge; if (oldvmspace->vm_refcnt == 1) return (0); fork_charge = 0; newvmspace = vmspace_fork(oldvmspace, &fork_charge); if (newvmspace == NULL) return (ENOMEM); if (!swap_reserve_by_cred(fork_charge, p->p_ucred)) { vmspace_free(newvmspace); return (ENOMEM); } PROC_VMSPACE_LOCK(p); p->p_vmspace = newvmspace; PROC_VMSPACE_UNLOCK(p); if (p == curthread->td_proc) pmap_activate(curthread); vmspace_free(oldvmspace); return (0); } /* * vm_map_lookup: * * Finds the VM object, offset, and * protection for a given virtual address in the * specified map, assuming a page fault of the * type specified. * * Leaves the map in question locked for read; return * values are guaranteed until a vm_map_lookup_done * call is performed. Note that the map argument * is in/out; the returned map must be used in * the call to vm_map_lookup_done. * * A handle (out_entry) is returned for use in * vm_map_lookup_done, to make that fast. * * If a lookup is requested with "write protection" * specified, the map may be changed to perform virtual * copying operations, although the data referenced will * remain the same. */ int vm_map_lookup(vm_map_t *var_map, /* IN/OUT */ vm_offset_t vaddr, vm_prot_t fault_typea, vm_map_entry_t *out_entry, /* OUT */ vm_object_t *object, /* OUT */ vm_pindex_t *pindex, /* OUT */ vm_prot_t *out_prot, /* OUT */ boolean_t *wired) /* OUT */ { vm_map_entry_t entry; vm_map_t map = *var_map; vm_prot_t prot; vm_prot_t fault_type = fault_typea; vm_object_t eobject; vm_size_t size; struct ucred *cred; RetryLookup:; vm_map_lock_read(map); /* * Lookup the faulting address. */ if (!vm_map_lookup_entry(map, vaddr, out_entry)) { vm_map_unlock_read(map); return (KERN_INVALID_ADDRESS); } entry = *out_entry; /* * Handle submaps. */ if (entry->eflags & MAP_ENTRY_IS_SUB_MAP) { vm_map_t old_map = map; *var_map = map = entry->object.sub_map; vm_map_unlock_read(old_map); goto RetryLookup; } /* * Check whether this task is allowed to have this page. */ prot = entry->protection; fault_type &= (VM_PROT_READ|VM_PROT_WRITE|VM_PROT_EXECUTE); if ((fault_type & prot) != fault_type || prot == VM_PROT_NONE) { vm_map_unlock_read(map); return (KERN_PROTECTION_FAILURE); } KASSERT((prot & VM_PROT_WRITE) == 0 || (entry->eflags & (MAP_ENTRY_USER_WIRED | MAP_ENTRY_NEEDS_COPY)) != (MAP_ENTRY_USER_WIRED | MAP_ENTRY_NEEDS_COPY), ("entry %p flags %x", entry, entry->eflags)); if ((fault_typea & VM_PROT_COPY) != 0 && (entry->max_protection & VM_PROT_WRITE) == 0 && (entry->eflags & MAP_ENTRY_COW) == 0) { vm_map_unlock_read(map); return (KERN_PROTECTION_FAILURE); } /* * If this page is not pageable, we have to get it for all possible * accesses. */ *wired = (entry->wired_count != 0); if (*wired) fault_type = entry->protection; size = entry->end - entry->start; /* * If the entry was copy-on-write, we either ... */ if (entry->eflags & MAP_ENTRY_NEEDS_COPY) { /* * If we want to write the page, we may as well handle that * now since we've got the map locked. * * If we don't need to write the page, we just demote the * permissions allowed. */ if ((fault_type & VM_PROT_WRITE) != 0 || (fault_typea & VM_PROT_COPY) != 0) { /* * Make a new object, and place it in the object * chain. Note that no new references have appeared * -- one just moved from the map to the new * object. */ if (vm_map_lock_upgrade(map)) goto RetryLookup; if (entry->cred == NULL) { /* * The debugger owner is charged for * the memory. */ cred = curthread->td_ucred; crhold(cred); if (!swap_reserve_by_cred(size, cred)) { crfree(cred); vm_map_unlock(map); return (KERN_RESOURCE_SHORTAGE); } entry->cred = cred; } vm_object_shadow(&entry->object.vm_object, &entry->offset, size); entry->eflags &= ~MAP_ENTRY_NEEDS_COPY; eobject = entry->object.vm_object; if (eobject->cred != NULL) { /* * The object was not shadowed. */ swap_release_by_cred(size, entry->cred); crfree(entry->cred); entry->cred = NULL; } else if (entry->cred != NULL) { VM_OBJECT_WLOCK(eobject); eobject->cred = entry->cred; eobject->charge = size; VM_OBJECT_WUNLOCK(eobject); entry->cred = NULL; } vm_map_lock_downgrade(map); } else { /* * We're attempting to read a copy-on-write page -- * don't allow writes. */ prot &= ~VM_PROT_WRITE; } } /* * Create an object if necessary. */ if (entry->object.vm_object == NULL && !map->system_map) { if (vm_map_lock_upgrade(map)) goto RetryLookup; entry->object.vm_object = vm_object_allocate(OBJT_DEFAULT, atop(size)); entry->offset = 0; if (entry->cred != NULL) { VM_OBJECT_WLOCK(entry->object.vm_object); entry->object.vm_object->cred = entry->cred; entry->object.vm_object->charge = size; VM_OBJECT_WUNLOCK(entry->object.vm_object); entry->cred = NULL; } vm_map_lock_downgrade(map); } /* * Return the object/offset from this entry. If the entry was * copy-on-write or empty, it has been fixed up. */ *pindex = UOFF_TO_IDX((vaddr - entry->start) + entry->offset); *object = entry->object.vm_object; *out_prot = prot; return (KERN_SUCCESS); } /* * vm_map_lookup_locked: * * Lookup the faulting address. A version of vm_map_lookup that returns * KERN_FAILURE instead of blocking on map lock or memory allocation. */ int vm_map_lookup_locked(vm_map_t *var_map, /* IN/OUT */ vm_offset_t vaddr, vm_prot_t fault_typea, vm_map_entry_t *out_entry, /* OUT */ vm_object_t *object, /* OUT */ vm_pindex_t *pindex, /* OUT */ vm_prot_t *out_prot, /* OUT */ boolean_t *wired) /* OUT */ { vm_map_entry_t entry; vm_map_t map = *var_map; vm_prot_t prot; vm_prot_t fault_type = fault_typea; /* * Lookup the faulting address. */ if (!vm_map_lookup_entry(map, vaddr, out_entry)) return (KERN_INVALID_ADDRESS); entry = *out_entry; /* * Fail if the entry refers to a submap. */ if (entry->eflags & MAP_ENTRY_IS_SUB_MAP) return (KERN_FAILURE); /* * Check whether this task is allowed to have this page. */ prot = entry->protection; fault_type &= VM_PROT_READ | VM_PROT_WRITE | VM_PROT_EXECUTE; if ((fault_type & prot) != fault_type) return (KERN_PROTECTION_FAILURE); /* * If this page is not pageable, we have to get it for all possible * accesses. */ *wired = (entry->wired_count != 0); if (*wired) fault_type = entry->protection; if (entry->eflags & MAP_ENTRY_NEEDS_COPY) { /* * Fail if the entry was copy-on-write for a write fault. */ if (fault_type & VM_PROT_WRITE) return (KERN_FAILURE); /* * We're attempting to read a copy-on-write page -- * don't allow writes. */ prot &= ~VM_PROT_WRITE; } /* * Fail if an object should be created. */ if (entry->object.vm_object == NULL && !map->system_map) return (KERN_FAILURE); /* * Return the object/offset from this entry. If the entry was * copy-on-write or empty, it has been fixed up. */ *pindex = UOFF_TO_IDX((vaddr - entry->start) + entry->offset); *object = entry->object.vm_object; *out_prot = prot; return (KERN_SUCCESS); } /* * vm_map_lookup_done: * * Releases locks acquired by a vm_map_lookup * (according to the handle returned by that lookup). */ void vm_map_lookup_done(vm_map_t map, vm_map_entry_t entry) { /* * Unlock the main-level map */ vm_map_unlock_read(map); } #include "opt_ddb.h" #ifdef DDB #include #include static void vm_map_print(vm_map_t map) { vm_map_entry_t entry; db_iprintf("Task map %p: pmap=%p, nentries=%d, version=%u\n", (void *)map, (void *)map->pmap, map->nentries, map->timestamp); db_indent += 2; for (entry = map->header.next; entry != &map->header; entry = entry->next) { db_iprintf("map entry %p: start=%p, end=%p\n", (void *)entry, (void *)entry->start, (void *)entry->end); { static char *inheritance_name[4] = {"share", "copy", "none", "donate_copy"}; db_iprintf(" prot=%x/%x/%s", entry->protection, entry->max_protection, inheritance_name[(int)(unsigned char)entry->inheritance]); if (entry->wired_count != 0) db_printf(", wired"); } if (entry->eflags & MAP_ENTRY_IS_SUB_MAP) { db_printf(", share=%p, offset=0x%jx\n", (void *)entry->object.sub_map, (uintmax_t)entry->offset); if ((entry->prev == &map->header) || (entry->prev->object.sub_map != entry->object.sub_map)) { db_indent += 2; vm_map_print((vm_map_t)entry->object.sub_map); db_indent -= 2; } } else { if (entry->cred != NULL) db_printf(", ruid %d", entry->cred->cr_ruid); db_printf(", object=%p, offset=0x%jx", (void *)entry->object.vm_object, (uintmax_t)entry->offset); if (entry->object.vm_object && entry->object.vm_object->cred) db_printf(", obj ruid %d charge %jx", entry->object.vm_object->cred->cr_ruid, (uintmax_t)entry->object.vm_object->charge); if (entry->eflags & MAP_ENTRY_COW) db_printf(", copy (%s)", (entry->eflags & MAP_ENTRY_NEEDS_COPY) ? "needed" : "done"); db_printf("\n"); if ((entry->prev == &map->header) || (entry->prev->object.vm_object != entry->object.vm_object)) { db_indent += 2; vm_object_print((db_expr_t)(intptr_t) entry->object.vm_object, 0, 0, (char *)0); db_indent -= 2; } } } db_indent -= 2; } DB_SHOW_COMMAND(map, map) { if (!have_addr) { db_printf("usage: show map \n"); return; } vm_map_print((vm_map_t)addr); } DB_SHOW_COMMAND(procvm, procvm) { struct proc *p; if (have_addr) { p = db_lookup_proc(addr); } else { p = curproc; } db_printf("p = %p, vmspace = %p, map = %p, pmap = %p\n", (void *)p, (void *)p->p_vmspace, (void *)&p->p_vmspace->vm_map, (void *)vmspace_pmap(p->p_vmspace)); vm_map_print((vm_map_t)&p->p_vmspace->vm_map); } #endif /* DDB */ Index: stable/11 =================================================================== --- stable/11 (revision 319276) +++ stable/11 (revision 319277) Property changes on: stable/11 ___________________________________________________________________ Modified: svn:mergeinfo ## -0,0 +0,1 ## Merged /head:r315272,315370