Make SysV-style shared memory and semaphore limits sysctl'able.

Instead of allocating a static amount of memory for the data
structures via valloc() in allocsys(), allocate things dynamically
using pool(9) when possible and malloc(9) when not.  The various
members of struct seminfo and struct shminfo are in kern.seminfo
and kern.shminfo respectively (not all members of kern.seminfo are
changable).

The data structures used still leave something to be desired but
things are not made worse in that respect by this commit.

1 files changed, 87 insertions, 1 deletions

diff --git a/lib/libc/gen/sysctl.3 b/lib/libc/gen/sysctl.3
index 5ba3f08b7b9..de1053d42aa 100644
--- a/lib/libc/gen/sysctl.3
+++ b/lib/libc/gen/sysctl.3
@@ -1,4 +1,4 @@
-.\"	$OpenBSD: sysctl.3,v 1.95 2002/11/25 03:04:48 wcobb Exp $
+.\"	$OpenBSD: sysctl.3,v 1.96 2002/12/17 23:11:32 millert Exp $
 .\"
 .\" Copyright (c) 1993
 .\"	The Regents of the University of California.  All rights reserved.
@@ -304,6 +304,8 @@ information.
 .It Dv KERN_RND No "	struct rndstats	no"
 .It Dv KERN_SAVED_IDS No "	integer	no"
 .It Dv KERN_SECURELVL No "	integer	raise only"
+.It Dv KERN_SEMINFO No "	node	not applicable"
+.It Dv KERN_SHMINFO No "	node	not applicable"
 .It Dv KERN_SOMINCONN No "	integer	yes"
 .It Dv KERN_SOMAXCONN No "	integer	yes"
 .It Dv KERN_SYSVIPC_INFO No "	node	not applicable"
@@ -535,6 +537,90 @@ Returns 1 if saved set-group-ID and saved set-user-ID are available.
 The system security level.
 This level may be raised by processes with appropriate privileges.
 It may only be lowered by process 1.
+.It Dv KERN_SEMINFO
+Return the elements of
+.Li struct seminfo .
+If the kernel is not compiled with System V style semaphore support,
+attempts to retrieve any of the
+.Dv KERN_SEMINFO
+values will fail with
+.Er EOPNOTSUPP .
+The third level names for the elements of
+.Li struct seminfo
+are detailed below.
+The changeable column shows whether a process with appropriate
+privileges may change the value.
+.Bl -column "KERN_SEMINFO_SEMMNI" "integer" "yes" -offset indent
+.It Sy "Third level name"	Type	Changeable
+.It Dv KERN_SEMINFO_SEMMNI	integer	yes
+.It Dv KERN_SEMINFO_SEMMNS	integer	yes
+.It Dv KERN_SEMINFO_SEMMNU	integer	yes
+.It Dv KERN_SEMINFO_SEMMSL	integer	yes
+.It Dv KERN_SEMINFO_SEMOPM	integer	yes
+.It Dv KERN_SEMINFO_SEMUME	integer	no
+.It Dv KERN_SEMINFO_SEMUSZ	integer	no
+.It Dv KERN_SEMINFO_SEMVMX	integer	no
+.It Dv KERN_SEMINFO_SEMAEM	integer	no
+.El
+.Pp
+The variables are as follows:
+.Bl -tag -width "123456"
+.It Dv KERN_SEMINFO_SEMMNI
+The maximum number of semaphore identifiers allowed.
+.It Dv KERN_SEMINFO_SEMMNS
+The maximum number of semaphores allowed in the system.
+.It Dv KERN_SEMINFO_SEMMNU
+The maximum number of semaphore undo structures allowed in the system.
+.It Dv KERN_SEMINFO_SEMMSL
+The maximum number of semaphores allowed per id.
+.It Dv KERN_SEMINFO_SEMOPM
+The maximum number of operations per
+.Xr semop 2
+call.
+.It Dv KERN_SEMINFO_SEMUME
+The maximum number of undo entries per process.
+.It Dv KERN_SEMINFO_SEMUSZ
+The size (in bytes) of the undo structure.
+.It Dv KERN_SEMINFO_SEMVMX
+The semaphore maximum value.
+.It Dv KERN_SEMINFO_SEMAEM
+The adjust on exit maximum value.
+.El
+.It Dv KERN_SHMINFO
+Return the elements of
+.Li struct shminfo .
+If the kernel is not compiled with System V style shared memory support,
+attempts to retrieve any of the
+.Dv KERN_SHMINFO
+values will fail with
+.Er EOPNOTSUPP .
+The third level names for the elements of
+.Li struct shminfo
+are detailed below.
+The changeable column shows whether a process with appropriate
+privileges may change the value.
+.Bl -column "KERN_SHMINFO_SHMMAX" "integer" "yes" -offset indent
+.It Sy "Third level name"	Type	Changeable
+.It Dv KERN_SHMINFO_SHMMAX	integer	yes
+.It Dv KERN_SHMINFO_SHMMIN	integer	yes
+.It Dv KERN_SHMINFO_SHMMNI	integer	yes
+.It Dv KERN_SHMINFO_SHMSEG	integer	yes
+.It Dv KERN_SHMINFO_SHMALL	integer	yes
+.El
+.Pp
+The variables are as follows:
+.Bl -tag -width "123456"
+.It Dv KERN_SHMINFO_SHMMAX
+The maximum shared memory segment size (in bytes).
+.It Dv KERN_SHMINFO_SHMMIN
+The minimum shared memory segment size (in bytes).
+.It Dv KERN_SHMINFO_SHMMNI
+The maximum number of shared memory identifiers in the system.
+.It Dv KERN_SHMINFO_SHMSEG
+The maximum number of shared memory segments per process.
+.It Dv KERN_SHMINFO_SHMALL
+The maximum amount of total shared memory allowed in the system (in pages).
+.El
 .It Dv KERN_SOMAXCONN
 Upper bound on the number of half-open connections a process can allow
 to be associated with a socket, using