Re: man/man8/ldconfig.8: document system-wide tunables

[DJ Delorie <dj@redhat.com>]

How about this?

diff --git a/man/man5/ld.so.conf.5 b/man/man5/ld.so.conf.5
index 481cf9152..aa27b73f6 100644
--- a/man/man5/ld.so.conf.5
+++ b/man/man5/ld.so.conf.5
@@ -9,6 +9,14 @@ .SH DESCRIPTION
 This file contains a list of directories,
 one per line,
 in which to search for libraries.
+The file allows lines to start with the word
+.I include
+followed by a path wildcard,
+and will include any files matching that wildcard.
+The file is parsed by
+.B \%ldconfig
+and the results stored in
+.IR /etc/ld.so.cache .
 .SH FILES
 .I /etc/ld.so.conf
 .SH SEE ALSO
diff --git a/man/man5/tunables.conf.5 b/man/man5/tunables.conf.5
new file mode 100644
index 000000000..d24eb0fa5
--- /dev/null
+++ b/man/man5/tunables.conf.5
@@ -0,0 +1,86 @@
+.TH tunables.conf 5 (date) "Linux man-pages (unreleased)"
+.SH NAME
+tunables.conf \- System-wide tunables configuration file
+.SH SYNOPSIS
+.nf
+.B /etc/tunables.conf
+.fi
+.SH DESCRIPTION
+Each line in the file
+.I /etc/tunables.conf
+specifies a tunable,
+which is a name and value separated by an equals sign.
+For a list of valid tunables,
+please consult the glibc manual.
+The file allows lines to start with the word
+.I include
+followed by a path wildcard,
+and will include any files matching that wildcard.
+The file is parsed by
+.B \%ldconfig
+and the results stored in
+.IR /etc/ld.so.cache .
+.P
+Each line may include zero or more words or symbols at the beginning:
+.TP
+.B overridable
+.TQ
+.B +
+Allow the tunable to be overridden by the environment variable
+(this is the default).
+.TP
+.B nonoverridable
+.TQ
+.B \-
+Do not allow the tunable to be overridden by the environment variable.
+.TP
+.B onlysecure
+.TQ
+.B @
+The tunable only applies to AT_SECURE
+(such as setuid, or elevated capabilities)
+processes.
+.TP
+.B nonsecure
+.TQ
+.B $
+The tunable only applies to non-AT_SECURE processes (this is the default).
+.TP
+.B anysecure
+.TQ
+.B *
+The tunable only applies to both AT_SECURE and non-AT_SECURE processes.
+.P
+The file may also contain
+.I filters ,
+which limit the tunables following it, up to the end of the file
+(or end of the included file, or start of a new included file)
+or a line with only
+.B []
+on it.  The syntax is:
+.IP
+.EX
+.RI [ filter : pattern ]
+.EE
+.TP
+.B proc
+The
+.I proc
+filter limits the following tunables to processes starting from the
+file matching the pattern.
+The file may be fully qualified or just the basename.
+.P
+Example config file:
+.IP
+.EX
+glibc.malloc.arenas_max=5
+onlysecure glibc.malloc.arenas_max=1
+-glibc.pthread.rseq=1
+[proc:/bin/bad.program]
+-glibc.pthread.rseq=0
+.EE
+.SH FILES
+.I /etc/ld.so.conf
+.SH SEE ALSO
+.BR ld.so (8),
+.BR ldconfig (8)
diff --git a/man/man8/ld.so.8 b/man/man8/ld.so.8
index 5f3c22ef2..40f129b71 100644
--- a/man/man8/ld.so.8
+++ b/man/man8/ld.so.8
@@ -792,7 +792,8 @@ .SH FILES
 .TP
 .I /etc/ld.so.cache
 File containing a compiled list of directories in which to search for
-shared objects and an ordered list of candidate shared objects.
+shared objects and an ordered list of candidate shared objects,
+and any system-wide tunables to be applied.
 See
 .BR ldconfig (8).
 .TP
diff --git a/man/man8/ldconfig.8 b/man/man8/ldconfig.8
index 9ac146b44..234169504 100644
--- a/man/man8/ldconfig.8
+++ b/man/man8/ldconfig.8
@@ -17,6 +17,8 @@ .SH SYNOPSIS
 .IR conf ]
 .RB [ \-r\~\c
 .IR root ]
+.RB [ \-t\~\c
+.IR tunconf ]
 .IR directory \~.\|.\|.
 .YS
 .SY /sbin/ldconfig
@@ -85,6 +87,13 @@ .SH DESCRIPTION
 .P
 Failure to follow this pattern may result in compatibility issues
 after an upgrade.
+.P
+If the file
+.I /etc/tunables.conf
+exists,
+it contains tunables to be applied to all processes.
+These tunables are stored
+in the cache and applied to every process at its startup.
 .SH OPTIONS
 .TP
 .BI \-\-format= fmt
@@ -157,6 +166,12 @@ .SH OPTIONS
 .I root
 as the root directory.
 .TP
+.BI \-t\~ tunconf
+Use
+.I tunconf
+instead of
+.IR /etc/tunables.conf .
+.TP
 .B \-\-verbose
 .TQ
 .B \-v
@@ -178,8 +193,6 @@ .SH OPTIONS
 is also specified,
 the cache is still rebuilt.
 .SH FILES
-.\" FIXME Since glibc-2.3.4, "include" directives are supported in ld.so.conf
-.\"
 .\" FIXME Since glibc-2.4, "hwcap" directives are supported in ld.so.conf
 .PD 0
 .TP
@@ -190,11 +203,17 @@ .SH FILES
 See
 .BR ld.so.conf (5).
 .TP
+.I /etc/tunables.conf
+See
+.BR tunables.conf (5).
+.TP
 .I /etc/ld.so.cache
 contains an ordered list of libraries found in the directories
 specified in
 .IR /etc/ld.so.conf ,
-as well as those found in the trusted directories.
+as well as those found in the trusted directories,
+and any system-wide tunables listed in
+.IR /etc/tunables.conf .
 .PD
 .SH SEE ALSO
 .BR ldd (1),