userfaultfd.2: Minor tweaks to Mike Rapoport's patch

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

man2/userfaultfd.2

@@ -101,11 +101,10 @@ needs to be aware of the changes in the virtual memory layout
 of the faulting process to avoid memory corruption.
 
 Starting from Linux 4.11,
-userfaultfd may notify the fault-handling threads about changes
+userfaultfd can also notify the fault-handling threads about changes
 in the virtual memory layout of the faulting process.
 In addition, if the faulting process invokes
-.BR fork (2)
+.BR fork (2),
-system call,
 the userfaultfd objects associated with the parent may be duplicated
 into the child process and the userfaultfd monitor will be notified
 about the file descriptor associated with the userfault objects
@@ -164,7 +163,6 @@ operation.
 
 Up to Linux 4.11,
 userfaultfd can be used only with anonymous private memory mappings.
-
 Since Linux 4.11,
 userfaultfd can be also used with hugetlbfs and shared memory mappings.
 
@@ -180,30 +178,29 @@ or an event required for the non-cooperative userfaultfd usage:
 .nf
 .in +4n
 struct uffd_msg {
-    __u8  event;                /* Type of event */
+    __u8  event;            /* Type of event */
     ...
     union {
         struct {
-            __u64 flags;        /* Flags describing fault */
+            __u64 flags;    /* Flags describing fault */
-            __u64 address;      /* Faulting address */
+            __u64 address;  /* Faulting address */
         } pagefault;
-        struct {
+
-            __u32 ufd;          /* userfault file descriptor
+        struct {            /* Since Linux 4.11 */
-                                   of the child process */
+            __u32 ufd;      /* Userfault file descriptor
-        } fork;                 /* since Linux 4.11 */
+                               of the child process */
-        struct {
+        } fork;
-            __u64 from;         /* old address of the
+
-                                   remapped area */
+        struct {            /* Since Linux 4.11 */
-            __u64 to;           /* new address of the
+            __u64 from;     /* Old address of remapped area */
-                                   remapped area */
+            __u64 to;       /* New address of remapped area */
-            __u64 len;          /* original mapping length */
+            __u64 len;      /* Original mapping length */
-        } remap;                /* since Linux 4.11 */
+        } remap;
-        struct {
+
-            __u64 start;        /* start address of the
+        struct {            /* Since Linux 4.11 */
-                                   removed area */
+            __u64 start;    /* Start address of removed area */
-            __u64 end;          /* end address of the
+            __u64 end;      /* End address of removed area */
-                                   removed area */
+        } remove;
-        } remove;               /* since Linux 4.11 */
         ...
     } arg;
 
@@ -252,8 +249,7 @@ field.
 .TP
 .BR UFFD_EVENT_FORK " (since Linux 4.11)"
 Generated when the faulting process invokes
-.BR fork (2)
+.BR fork (2).
-system call.
 The event details are available in the
 .I fork
 field.
@@ -261,8 +257,7 @@ field.
 .TP
 .BR UFFD_EVENT_REMAP " (since Linux 4.11)"
 Generated when the faulting process invokes
-.BR mremap (2)
+.BR mremap (2).
-system call.
 The event details are available in the
 .I remap
 field.
@@ -270,7 +265,7 @@ field.
 .BR UFFD_EVENT_REMOVE " (since Linux 4.11)"
 Generated when the faulting process invokes
 .BR madvise (2)
-system call with
+with
 .BR MADV_DONTNEED
 or
 .BR MADV_REMOVE
@@ -283,11 +278,10 @@ field.
 Generated when the faulting process unmaps a memory range,
 either explicitly using
 .BR munmap (2)
-system call or implicitly during
+or implicitly during
 .BR mmap (2)
 or
-.BR mremap (2)
+.BR mremap (2).
-system calls.
 The event details are available in the
 .I remove
 field.