prctl.2: ffix

[thirdparty/man-pages.git] / man2 / subpage_prot.2

diff --git a/man2/subpage_prot.2 b/man2/subpage_prot.2
index 56def7506af34b97733fb77ce1dbd05744c8cabf..78e978ecbb350ad598811685c01f344dc8f40462 100644 (file)
--- a/man2/subpage_prot.2
+++ b/man2/subpage_prot.2
@@ -1,6 +1,7 @@
 .\" Copyright (c) 2010 Michael Kerrisk <mtk.manpages@gmail.com>
 .\" based on a proposal from Stephan Mueller <smueller@atsec.com>
 .\"
+.\" %%%LICENSE_START(VERBATIM)
 .\" Permission is granted to make and distribute verbatim copies of this
 .\" manual provided the copyright notice and this permission notice are
 .\" preserved on all copies.
@@ -11,21 +12,22 @@
 .\" a permission notice identical to this one.
 .\"
 .\" Since the Linux kernel and libraries are constantly changing, this
-.\" manual page may be incorrect or out-of-date.  The author(s) assume.
-.\" no responsibility for errors or omissions, or for damages resulting.
-.\" from the use of the information contained herein.  The author(s) may.
-.\" not have taken the same level of care in the production of this.
-.\" manual, which is licensed free of charge, as they might when working.
+.\" manual page may be incorrect or out-of-date.  The author(s) assume
+.\" no responsibility for errors or omissions, or for damages resulting
+.\" from the use of the information contained herein.  The author(s) may
+.\" not have taken the same level of care in the production of this
+.\" manual, which is licensed free of charge, as they might when working
 .\" professionally.
 .\"
 .\" Formatted or processed versions of this manual, if unaccompanied by
 .\" the source, must acknowledge the copyright and authors of this work.
+.\" %%%LICENSE_END
 .\"
 .\" Various pieces of text taken from the kernel source and the commentary
 .\" in kernel commit fa28237cfcc5827553044cbd6ee52e33692b0faa
 .\" both written by Paul Mackerras <paulus@samba.org>
 .\"
-.TH SUBPAGE_PROT 2 2010-10-30 "Linux" "Linux Programmer's Manual"
+.TH SUBPAGE_PROT 2 2019-03-06 "Linux" "Linux Programmer's Manual"
 .SH NAME
 subpage_prot \- define a subpage protection for an address range
 .SH SYNOPSIS
@@ -33,25 +35,28 @@ subpage_prot \- define a subpage protection for an address range
 .BI "long subpage_prot(unsigned long " addr ", unsigned long " len ,
 .BI "                  uint32_t *" map ");
 .fi
+.PP
+.IR Note :
+There is no glibc wrapper for this system call; see NOTES.
 .SH DESCRIPTION
 The PowerPC-specific
 .BR subpage_prot ()
 system call provides the facility to control the access
-permissions on individual 4kB subpages on systems configured with
-a page size of 64kB.
-
+permissions on individual 4\ kB subpages on systems configured with
+a page size of 64\ kB.
+.PP
 The protection map is applied to the memory pages in the region starting at
 .I addr
 and continuing for
 .I len
 bytes.
 Both of these arguments must be aligned to a 64-kB boundary.
-
+.PP
 The protection map is specified in the buffer pointed to by
 .IR map .
-The map has 2 bits per 4kB subpage;
-thus each 32-bit word specifies the protections of 16 4kB subpages
-inside a 64kB page
+The map has 2 bits per 4\ kB subpage;
+thus each 32-bit word specifies the protections of 16 4\ kB subpages
+inside a 64\ kB page
 (so, the number of 32-bit words pointed to by
 .I map
 should equate to the number of 64-kB pages specified by
@@ -91,6 +96,9 @@ No library support is provided.
 .SH CONFORMING TO
 This system call is Linux-specific.
 .SH NOTES
+Glibc does not provide a wrapper for this system call; call it using
+.BR syscall (2).
+.PP
 Normal page protections (at the 64-kB page level) also apply;
 the subpage protection mechanism is an additional constraint,
 so putting 0 in a 2-bit field won't allow writes to a page that is otherwise
@@ -112,14 +120,14 @@ Implicit in this is that the regions of the address space that are
 protected are switched to use 4-kB hardware pages rather than 64-kB
 hardware pages (on machines with hardware 64-kB page support).
 .\" In the initial implementation, it was the case that:
-.\"     In fact the whole process is switched to use 4k hardware pages when the
+.\"     In fact the whole process is switched to use 4 kB hardware pages when the
 .\"     subpage_prot system call is used, but this could be improved in future
 .\"     to switch only the affected segments.
 .\" But Paul Mackerass says (Oct 2010): I'm pretty sure we now only switch
 .\" the affected segment, not the whole process.
 .SH SEE ALSO
 .BR mprotect (2),
-.BR syscall (2);
-.br
-the kernel source file
-.IR Documentation/vm/hugetlbpage.txt .
+.BR syscall (2)
+.PP
+.IR Documentation/admin-guide/mm/hugetlbpage.rst
+in the Linux kernel source tree