Index: head/lib/libc/string/memset.3
===================================================================
--- head/lib/libc/string/memset.3	(revision 357682)
+++ head/lib/libc/string/memset.3	(revision 357683)
@@ -1,132 +1,133 @@
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 .\"     @(#)memset.3	8.1 (Berkeley) 6/4/93
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 .Dd August 19, 2018
 .Dt MEMSET 3
 .Os
 .Sh NAME
 .Nm memset
 .Nd write a byte to byte string
 .Sh LIBRARY
 .Lb libc
 .Sh SYNOPSIS
 .In string.h
 .Ft void *
 .Fn memset "void *dest" "int c" "size_t len"
 .Fd #define __STDC_WANT_LIB_EXT1__ 1
 .Ft errno_t
 .Fn memset_s "void *dest" "rsize_t destsz" "int c" "rsize_t len"
 .Sh DESCRIPTION
 The
 .Fn memset
 function
 writes
 .Fa len
 bytes of value
 .Fa c
 (converted to an
 .Vt "unsigned char" )
 to the string
 .Fa dest .
 Undefined behaviour from
 .Fn memset ,
 resulting from storage overflow, will occur if
 .Fa len
-is greater than the length of buffer
-.Fa dest .
+is greater than the length of the
+.Fa dest
+buffer.
 The behaviour is also undefined if
 .Fa dest
 is an invalid pointer.
 .Pp
 The
 .Fn memset_s
 function behaves the same as
 .Fn memset
 except that an error is returned and the currently registered
 runtime-constraint handler is called if
 .Fa dest
 is a null pointer,
 .Fa destsz
 or
 .Fa len
 is greater than
 .Dv RSIZE_MAX ,
 or
 .Fa len
 is greater than
 .Fa destsz
 (buffer overflow would occur).
 The runtime-constraint handler is called first and may not return.
 If it does return, an error is returned to the caller.
 Like
 .Xr explicit_bzero 3 ,
 .Fn memset_s
 is not removed through Dead Store Elimination (DSE), making it useful for
 clearing sensitive data.
 In contrast
 .Fn memset
 function
 may be optimized away if the object modified by the function is not accessed
 again.
 To clear memory that will not subsequently be accessed it is advised to use
 .Fn memset_s
 instead of
 .Fn memset .
 For instance, a buffer containing a password should be cleared with
 .Fn memset_s
 before
 .Xr free 3 .
 .Sh RETURN VALUES
 The
 .Fn memset
 function returns its first argument.
 The
 .Fn memset_s
 function returns zero on success, non-zero on error.
 .Sh SEE ALSO
 .Xr bzero 3 ,
 .Xr explicit_bzero 3 ,
 .Xr set_constraint_handler_s 3 ,
 .Xr swab 3 ,
 .Xr wmemset 3
 .Sh STANDARDS
 The
 .Fn memset
 function
 conforms to
 .St -isoC .
 .Fn memset_s
 conforms to
 .St -isoC-2011
 K.3.7.4.1.