From d88d01c6b8f5b77056134f7c96060da87f6ff4e5 Mon Sep 17 00:00:00 2001
From: Michael Kerrisk <mtk.manpages@gmail.com>
Date: Sun, 20 Nov 2016 21:43:44 +0100
Subject: [PATCH] mprotect.2: Various fixes to Eugene Syromyatnikov's text

Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
---
 man2/mprotect.2 | 49 +++++++++++++++++++++++--------------------------
 1 file changed, 23 insertions(+), 26 deletions(-)

diff --git a/man2/mprotect.2 b/man2/mprotect.2
index d7ffd76d2..f4896814e 100644
--- a/man2/mprotect.2
+++ b/man2/mprotect.2
@@ -72,19 +72,20 @@ The memory can be executed.
 .TP
 .BR PROT_SEM " (since Linux 2.5.7)"
 The memory can be used for atomic operations.
-It was introduced as part of
+This flag was introduced as part of the
 .BR futex (2)
-implementation (in order to guarantee ability to perform atomic
-operations required by its commands such as
+implementation (in order to guarantee the ability to perform atomic
+operations required by commands such as
 .BR FUTEX_WAIT ),
-but not actually used in any currently supported architecture so far.
-.\" aba46c5027cb59d98052231b36efcbbde9c77a1d ef3d3246a0d06be622867d21af25f997aeeb105f
+but is not currently used in on any architecture.
 .TP
 .BR PROT_SAO " (since Linux 2.6.26)"
+.\" commit aba46c5027cb59d98052231b36efcbbde9c77a1d
+.\" commit ef3d3246a0d06be622867d21af25f997aeeb105f
 The memory should have strong access ordering.
 This feature is specific to
-PowerPC architecture
-(version 2.06 of architecture specification adds SAO CPU feature,
+the PowerPC architecture
+(version 2.06 of the architecture specification adds the SAO CPU feature,
 and it is available on POWER 7 or PowerPC A2, for example).
 .PP
 Additionally (since Linux 2.6.0),
@@ -96,17 +97,22 @@ can have one of the following flags set:
 .\"			mm->def_flags | VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC;
 .\" And calc_vm_flag_bits converts only GROWSDOWN/DENYWRITE/LOCKED.
 .B PROT_GROWSUP
-Apply protection mode up to the end of the mapping which grows up
-(it should be a stack segment on HP PA-RISC,
-since there are no other ways to map a segment with
-.B VM_GROWSUP
-even if architecture has support for it.)
+Apply the protection mode up to the end of a mapping
+that grows upwards.
+(Such mappings are created for the stack area on
+architectures\(emfor example, HP-PARISC\(emthat
+have an upwardly growing stack.)
+.\" The VMA is one that was marked with VM_GROWSUP by the kernel
+.\" when the stack was created. Note that (unlike VM_GROWSDOWN),
+.\" there is no mmap() flag (analogous to MAP_GROWSDOWN) for
+.\" creating a VMA that is marked VM_GROWSUP.
 .TP
 .B PROT_GROWSDOWN
-Apply protection mode down to the beginning of the mapping which grows down
-(it should be stack segment or mapped with
+Apply the protection mode down to the beginning of a mapping
+that grows downward
+(which should be a stack segment or a segment mapped with the
 .B MAP_GROWSDOWN
-flag set.)
+flag set).
 .PP
 Like
 .BR mprotect (),
@@ -164,22 +170,13 @@ were specified in
 .IR prot .
 .TP
 .BR EINVAL
-Invalid (other than
-.BR PROT_READ ,
-.BR PROT_WRITE ,
-.BR PROT_EXEC ,
-.BR PROT_SEM ,
-.BR PROT_SAO
-(on PowerPC only),
-.BR PROT_GROWSUP ,
-.BR PROT_GROWSDOWN )
-flags specified in
+Invalid flags specified in
 .IR prot .
 .TP
 .BR EINVAL
 (PowerPC architecture)
 .B PROT_SAO
-specified in
+was specified in
 .IR prot ,
 but SAO hardware feature is not available.
 .TP