5 files changed, 20 insertions, 10 deletions

diff --git a/lib/libc/sys/brk.2 b/lib/libc/sys/brk.2
index 31dea32a0923f..0eb61d582cbfa 100644
--- a/lib/libc/sys/brk.2
+++ b/lib/libc/sys/brk.2
@@ -28,7 +28,7 @@
 .\"     @(#)brk.2	8.4 (Berkeley) 5/1/95
 .\" $FreeBSD$
 .\"
-.Dd July 12, 1999
+.Dd May 24, 2018
 .Dt BRK 2
 .Os
 .Sh NAME
@@ -38,7 +38,6 @@
 .Sh LIBRARY
 .Lb libc
 .Sh SYNOPSIS
-.In sys/types.h
 .In unistd.h
 .Ft int
 .Fn brk "const void *addr"
@@ -52,6 +51,10 @@ and
 .Fn sbrk
 functions are legacy interfaces from before the
 advent of modern virtual memory management.
+They are deprecated and not present on the arm64 or riscv architectures.
+The
+.Xr mmap 2
+interface should be used to allocate pages instead.
 .Ef
 .Pp
 The
@@ -153,6 +156,11 @@ The
 .Fn brk
 function appeared in
 .At v7 .
+.Fx 11.0
+introduced the arm64 and riscv architectures which do not support
+.Fn brk
+or
+.Fn sbrk .
 .Sh BUGS
 Mixing
 .Fn brk
@@ -169,3 +177,9 @@ It is not possible to distinguish this
 from a failure caused by exceeding the maximum size of
 the data segment without consulting
 .Xr getrlimit 2 .
+.Pp
+.Fn sbrk
+is sometimes used to monitor heap use by calling with an argument of 0.
+The result is unlikely to reflect actual utilization in combination with an
+.Xr mmap 2
+based malloc.
diff --git a/lib/libc/sys/getgid.2 b/lib/libc/sys/getgid.2
index b03040bdf0076..5bd2a94b9dc10 100644
--- a/lib/libc/sys/getgid.2
+++ b/lib/libc/sys/getgid.2
@@ -28,7 +28,7 @@
 .\"     @(#)getgid.2	8.1 (Berkeley) 6/4/93
 .\" $FreeBSD$
 .\"
-.Dd June 4, 1993
+.Dd December 15, 2015
 .Dt GETGID 2
 .Os
 .Sh NAME
@@ -38,7 +38,6 @@
 .Sh LIBRARY
 .Lb libc
 .Sh SYNOPSIS
-.In sys/types.h
 .In unistd.h
 .Ft gid_t
 .Fn getgid void
diff --git a/lib/libc/sys/getpid.2 b/lib/libc/sys/getpid.2
index aefa7708e7ca7..ab69f7117aebf 100644
--- a/lib/libc/sys/getpid.2
+++ b/lib/libc/sys/getpid.2
@@ -28,7 +28,7 @@
 .\"     @(#)getpid.2	8.1 (Berkeley) 6/4/93
 .\" $FreeBSD$
 .\"
-.Dd November 2, 2006
+.Dd December 15, 2015
 .Dt GETPID 2
 .Os
 .Sh NAME
@@ -38,7 +38,6 @@
 .Sh LIBRARY
 .Lb libc
 .Sh SYNOPSIS
-.In sys/types.h
 .In unistd.h
 .Ft pid_t
 .Fn getpid void
diff --git a/lib/libc/sys/read.2 b/lib/libc/sys/read.2
index e99665fa6b2f5..a0a7be838c0bb 100644
--- a/lib/libc/sys/read.2
+++ b/lib/libc/sys/read.2
@@ -28,7 +28,7 @@
 .\"     @(#)read.2	8.4 (Berkeley) 2/26/94
 .\" $FreeBSD$
 .\"
-.Dd September 11, 2013
+.Dd December 15, 2015
 .Dt READ 2
 .Os
 .Sh NAME
@@ -40,7 +40,6 @@
 .Sh LIBRARY
 .Lb libc
 .Sh SYNOPSIS
-.In sys/types.h
 .In unistd.h
 .Ft ssize_t
 .Fn read "int fd" "void *buf" "size_t nbytes"
diff --git a/lib/libc/sys/write.2 b/lib/libc/sys/write.2
index a06e7c9d89f64..0bfe56530f7c9 100644
--- a/lib/libc/sys/write.2
+++ b/lib/libc/sys/write.2
@@ -28,7 +28,7 @@
 .\"     @(#)write.2	8.5 (Berkeley) 4/2/94
 .\" $FreeBSD$
 .\"
-.Dd September 11, 2013
+.Dd December 15, 2015
 .Dt WRITE 2
 .Os
 .Sh NAME
@@ -40,7 +40,6 @@
 .Sh LIBRARY
 .Lb libc
 .Sh SYNOPSIS
-.In sys/types.h
 .In unistd.h
 .Ft ssize_t
 .Fn write "int fd" "const void *buf" "size_t nbytes"