diff --git a/share/man/man9/vm_map_protect.9 b/share/man/man9/vm_map_protect.9 index 5e58074ebda7..048f574aef2b 100644 --- a/share/man/man9/vm_map_protect.9 +++ b/share/man/man9/vm_map_protect.9 @@ -1,108 +1,138 @@ .\" .\" Copyright (c) 2003 Bruce M Simpson +.\" Copyright (c) 2021 The FreeBSD Foundation, Inc. .\" All rights reserved. .\" +.\" Parts of this documentation were written by +.\" Konstantin Belousov under sponsorship +.\" from the FreeBSD Foundation. +.\" .\" 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. .\" .\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR 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 AUTHOR 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. .\" .\" $FreeBSD$ .\" -.Dd June 20, 2019 +.Dd January 23, 2021 .Dt VM_MAP_PROTECT 9 .Os .Sh NAME .Nm vm_map_protect .Nd apply protection bits to a virtual memory region .Sh SYNOPSIS .In sys/param.h .In vm/vm.h .In vm/vm_map.h .Ft int .Fo vm_map_protect -.Fa "vm_map_t map" "vm_offset_t start" "vm_offset_t end" "vm_prot_t new_prot" -.Fa "boolean_t set_max" +.Fa "vm_map_t map" +.Fa "vm_offset_t start" +.Fa "vm_offset_t end" +.Fa "vm_prot_t new_prot" +.Fa "vm_prot_t new_maxprot" +.Fa "int flags" .Fc .Sh DESCRIPTION The .Fn vm_map_protect -function sets the protection bits of the address region bounded by +function sets the protection bits and maximum protection bits of the address +region bounded by .Fa start and .Fa end within the map -.Fa map -to +.Fa map . +.Pp +If the +.Fa flags +argument has the +.Dv VM_MAP_PROTECT_SET_PROT +bit set, then the effective protection is set to .Fa new_prot . -The value specified by -.Fa new_prot -may not include any protection bits that are not set in -.Va max_protection -on every entry within the range. .Pp -If -.Fa set_max -is TRUE, +If the +.Fa flags +argument has the +.Dv VM_MAP_PROTECT_SET_MAXPROT +bit set, then the maximum protection is set to +.Fa new_maxprot . +Protection bits not included into +.Fa new_maxprot +will be cleared from existing entries. +.Pp +The values specified by .Fa new_prot -is treated as the new +and +.Fa new_maxprot +are not allowed to include any protection bits that are not set in existing .Va max_protection -setting for each underlying entry. -Protection bits not included -.Fa new_prot -will be cleared from existing entries. -If -.Fa set_max -is FALSE only the -.Va protection -field is affected. +on every entry within the range. +The operation will fail if this condition is violated. +For instance, this prevents upgrading a shared mapping of a read-only file +from read-only to read-write. .Pp -The range MUST be contiguous, and MUST NOT contain sub-maps. +The specified range must not contain sub-maps. .Sh IMPLEMENTATION NOTES The function acquires a lock on the .Fa map for the duration, by calling .Xr vm_map_lock 9 . +Also, any in-progress wiring operation on the map affecting the specified +range will cause +.Nm +to sleep, waiting for completion. .Sh RETURN VALUES -The -.Fn vm_map_protect -function returns -.Dv KERN_SUCCESS -if the protection bits could be set successfully. -.Pp -If a sub-map entry was encountered in the range, -.Dv KERN_INVALID_ARGUMENT -is returned. -If the value of +.Bl -tag -width "Dv KERN_PROTECTION_FAILURE" +.It Dv KERN_SUCCESS +The specified protection bits were set successfully. +.It Dv KERN_INVALID_ARGUMENT +A sub-map entry was encountered in the range, +.It Dv KERN_PROTECTION_FAILURE +The value of .Fa new_prot -would exceed +or +.Fa new_maxprot +exceed .Va max_protection -for an entry within the range, -.Dv KERN_PROTECTION_FAILURE -is returned. -If a copy-on-write mapping is transitioned from read-only to -read-write, and too little swap space is available for backing the -copied pages, -.Dv KERN_RESOURCE_SHORTAGE -is returned. +for an entry within the range. +.It Dv KERN_PROTECTION_FAILURE +The map does not allow simultaneous setting of write and execute permissions, +but +.Fa new_prot +has both +.Dv VM_PROT_WRITE +and +.Dv VM_PROT_EXECUTE +set. +.It Dv KERN_RESOURCE_SHORTAGE +A copy-on-write mapping is transitioned from read-only to +read-write, and not enough swap space is available to back the +copied pages. +.It Dv KERN_OUT_OF_BOUNDS +Both new protection and new maximum protection updates were requested, +but the specified +.Fa new_prot +is not a subset of +.Fa new_maxprot . .Sh SEE ALSO .Xr vm_map 9 .Sh AUTHORS This manual page was written by .An Bruce M Simpson Aq Mt bms@spc.org .