ioctl_userfaultfd.2, userfaultfd.2: Minor tweaks to Peter Xu's patches

Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>

man2/ioctl_userfaultfd.2

@@ -212,7 +212,7 @@ memory accesses to the regions registered with userfaultfd.
 .BR UFFD_FEATURE_THREAD_ID " (since Linux 4.14)"
 If this feature bit is set,
 .I uffd_msg.pagefault.feat.ptid
-will be set to the faulted thread ID for each page fault message.
+will be set to the faulted thread ID for each page-fault message.
 .PP
 The returned
 .I ioctls
@@ -450,7 +450,7 @@ Do not wake up the thread that waits for page-fault resolution
 Copy the page with read-only permission.
 This allows the user to trap the next write to the page,
 which will block and generate another write-protect userfault message.
-This is only used when both
+This is used only when both
 .B UFFDIO_REGISTER_MODE_MISSING
 and
 .B UFFDIO_REGISTER_MODE_WP
@@ -667,7 +667,7 @@ structure was not a multiple of the system page size; or
 .I len
 was zero; or the specified range was otherwise invalid.
 .SS UFFDIO_WRITEPROTECT (Since Linux 5.7)
-Write-protect or write-unprotect an userfaultfd registered memory range
+Write-protect or write-unprotect a userfaultfd-registered memory range
 registered with mode
 .BR UFFDIO_REGISTER_MODE_WP .
 .PP
@@ -693,13 +693,13 @@ When this mode bit is set,
 the ioctl will be a write-protect operation upon the memory range specified by
 .IR range .
 Otherwise it'll be a write-unprotect operation upon the specified range,
-which can be used to resolve an userfaultfd write-protect page fault.
+which can be used to resolve a userfaultfd write-protect page fault.
 .TP
 .B UFFDIO_WRITEPROTECT_MODE_DONTWAKE
 When this mode bit is set,
 do not wake up any thread that waits for
 page-fault resolution after the operation.
-This could only be specified if
+This can be specified only if
 .B UFFDIO_WRITEPROTECT_MODE_WP
 is not specified.
 .PP

man2/userfaultfd.2

@@ -83,10 +83,10 @@ Userfaultfd supports two modes of registration:
 .BR UFFDIO_REGISTER_MODE_MISSING " (since 4.10)"
 When registered with
 .B UFFDIO_REGISTER_MODE_MISSING
-mode, the userspace will receive a page fault message
+mode, user-space will receive a page-fault notification
 when a missing page is accessed.
 The faulted thread will be stopped from execution until the page fault is
-resolved from the userspace by either an
+resolved from user-space by either an
 .B UFFDIO_COPY
 or an
 .B UFFDIO_ZEROPAGE
@@ -95,17 +95,17 @@ ioctl.
 .BR UFFDIO_REGISTER_MODE_WP " (since 5.7)"
 When registered with
 .B UFFDIO_REGISTER_MODE_WP
-mode, the userspace will receive a page fault message
+mode, user-space will receive a page-fault notification
 when a write-protected page is written.
 The faulted thread will be stopped from execution
-until the userspace write-unprotect the page using an
+until user-space write-unprotects the page using an
 .B UFFDIO_WRITEPROTECT
 ioctl.
 .PP
 Multiple modes can be enabled at the same time for the same memory range.
 .PP
-Since Linux 4.14, userfaultfd page fault message can selectively embed
-faulting thread ID information into the fault message.
+Since Linux 4.14, a userfaultfd page-fault notification can selectively embed
+faulting thread ID information into the notification.
 One needs to enable this feature explicitly using the
 .B UFFD_FEATURE_THREAD_ID
 feature bit when initializing the userfaultfd context.
@@ -177,10 +177,12 @@ One should check against the feature bit
 .B UFFD_FEATURE_PAGEFAULT_FLAG_WP
 before using this feature.
 Similar to the original userfaultfd missing mode, the write-protect mode will
-generate an userfaultfd message when the protected page is written.
+generate a userfaultfd notification when the protected page is written.
 The user needs to resolve the page fault by unprotecting the faulted page and
-kick the faulted thread to continue.
-For more information, please refer to "Userfaultfd write-protect mode" section.
+kicking the faulted thread to continue.
+For more information,
+please refer to the "Userfaultfd write-protect mode" section.
+.\"
 .SS Userfaultfd operation
 After the userfaultfd object is created with
 .BR userfaultfd (),
@@ -276,11 +278,11 @@ with the mode set to
 .BR "UFFDIO_REGISTER_MODE_MISSING | UFFDIO_REGISTER_MODE_WP" .
 When there is only
 .B UFFDIO_REGISTER_MODE_WP
-registered, the userspace will
+registered, user-space will
 .I not
-receive any message when a missing page is written.
-Instead, the userspace will only receive a write-protect page fault message
-when an existing but write-protected page got written.
+receive any notification when a missing page is written.
+Instead, user-space will receive a write-protect page-fault notification
+only when an existing but write-protected page got written.
 .PP
 After the
 .B UFFDIO_REGISTER
@@ -295,16 +297,17 @@ should be set to
 .BR UFFDIO_WRITEPROTECT_MODE_WP .
 .PP
 When a write-protect event happens,
-the userspace will receive a page fault message whose
+user-space will receive a page-fault notification whose
 .I uffd_msg.pagefault.flags
 will be with
 .B UFFD_PAGEFAULT_FLAG_WP
 flag set.
-Note: since only writes can trigger such kind of fault,
-write-protect messages will always be with
+Note: since only writes can trigger this kind of fault,
+write-protect notifications will always have the
 .B UFFD_PAGEFAULT_FLAG_WRITE
-bit set too along with bit
-.BR UFFD_PAGEFAULT_FLAG_WP .
+bit set along with the
+.BR UFFD_PAGEFAULT_FLAG_WP
+bit.
 .PP
 To resolve a write-protection page fault, the user should initiate another
 .B UFFDIO_WRITEPROTECT
@@ -314,7 +317,7 @@ should have the flag
 .B UFFDIO_WRITEPROTECT_MODE_WP
 cleared upon the faulted page or range.
 .PP
-Write-protect mode only supports private anonymous memory.
+Write-protect mode supports only private anonymous memory.
 .SS Reading from the userfaultfd structure
 Each
 .BR read (2)
@@ -464,8 +467,8 @@ otherwise it is a read fault.
 .B UFFD_PAGEFAULT_FLAG_WP
 If the address is in a range that was registered with the
 .B UFFDIO_REGISTER_MODE_WP
-flag, when this bit is set it means it's a write-protect fault.
-Otherwise it's a page missing fault.
+flag, when this bit is set, it means it's a write-protect fault.
+Otherwise it's a page-missing fault.
 .RE
 .TP
 .I pagefault.feat.pid