Commit Graph

102 Commits

Author SHA1 Message Date
Alexey Dobriyan f221e726bf sysctl: simplify ->strategy
name and nlen parameters passed to ->strategy hook are unused, remove
them.  In general ->strategy hook should know what it's doing, and don't
do something tricky for which, say, pointer to original userspace array
may be needed (name).

Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Acked-by: David S. Miller <davem@davemloft.net> [ networking bits ]
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: David Howells <dhowells@redhat.com>
Cc: Matt Mackall <mpm@selenic.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-10-16 11:21:47 -07:00
Al Viro 9043476f72 [PATCH] sanitize proc_sysctl
* keep references to ctl_table_head and ctl_table in /proc/sys inodes
* grab the former during operations, use the latter for access to
  entry if that succeeds
* have ->d_compare() check if table should be seen for one who does lookup;
  that allows us to avoid flipping inodes - if we have the same name resolve
  to different things, we'll just keep several dentries and ->d_compare()
  will reject the wrong ones.
* have ->lookup() and ->readdir() scan the table of our inode first, then
  walk all ctl_table_header and scan ->attached_by for those that are
  attached to our directory.
* implement ->getattr().
* get rid of insane amounts of tree-walking
* get rid of the need to know dentry in ->permission() and of the contortions
  induced by that.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2008-07-26 20:53:12 -04:00
Al Viro ae7edecc9b [PATCH] sysctl: keep track of tree relationships
In a sense, that's the heart of the series.  It's based on the following
property of the trees we are actually asked to add: they can be split into
stem that is already covered by registered trees and crown that is entirely
new.  IOW, if a/b and a/c/d are introduced by our tree, then a/c is also
introduced by it.

That allows to associate tree and table entry with each node in the union;
while directory nodes might be covered by many trees, only one will cover
the node by its crown.  And that will allow much saner logics for /proc/sys
in the next patches.  This patch introduces the data structures needed to
keep track of that.

When adding a sysctl table, we find a "parent" one.  Which is to say,
find the deepest node on its stem that already is present in one of the
tables from our table set or its ancestor sets.  That table will be our
parent and that node in it - attachment point.  Add our table to list
anchored in parent, have it refer the parent and contents of attachment
point.  Also remember where its crown lives.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2008-07-26 20:53:11 -04:00
Al Viro f7e6ced406 [PATCH] allow delayed freeing of ctl_table_header
Refcount the sucker; instead of freeing it by the end of unregistration
just drop the refcount and free only when it hits zero.  Make sure that
we _always_ make ->unregistering non-NULL in start_unregistering().

That allows anybody to get a reference to such puppy, preventing its
freeing and reuse.  It does *not* block unregistration.  Anybody who
holds such a reference can
	* try to grab a "use" reference (ctl_head_grab()); that will
succeeds if and only if it hadn't entered unregistration yet.  If it
succeeds, we can use it in all normal ways until we release the "use"
reference (with ctl_head_finish()).  Note that this relies on having
->unregistering become non-NULL in all cases when one starts to unregister
the sucker.
	* keep pointers to ctl_table entries; they *can* be freed if
the entire thing is unregistered.  However, if ctl_head_grab() succeeds,
we know that unregistration had not happened (and will not happen until
ctl_head_finish()) and such pointers can be used safely.

IOW, now we can have inodes under /proc/sys keep references to ctl_table
entries, protecting them with references to ctl_table_header and
grabbing the latter for the duration of operations that require access
to ctl_table.  That won't cause deadlocks, since unregistration will not
be stopped by mere keeping a reference to ctl_table_header.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2008-07-26 20:53:09 -04:00
Al Viro 734550921e [PATCH] beginning of sysctl cleanup - ctl_table_set
New object: set of sysctls [currently - root and per-net-ns].
Contains: pointer to parent set, list of tables and "should I see this set?"
method (->is_seen(set)).
Current lists of tables are subsumed by that; net-ns contains such a beast.
->lookup() for ctl_table_root returns pointer to ctl_table_set instead of
that to ->list of that ctl_table_set.

[folded compile fixes by rdd for configs without sysctl]

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2008-07-26 20:53:08 -04:00
Pavel Emelyanov d7321cd624 sysctl: add the ->permissions callback on the ctl_table_root
When reading from/writing to some table, a root, which this table came from,
may affect this table's permissions, depending on who is working with the
table.

The core hunk is at the bottom of this patch.  All the rest is just pushing
the ctl_table_root argument up to the sysctl_perm() function.

This will be mostly (only?) used in the net sysctls.

Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Acked-by: David S. Miller <davem@davemloft.net>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Alexey Dobriyan <adobriyan@sw.ru>
Cc: Denis V. Lunev <den@openvz.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-29 08:06:23 -07:00
Pavel Emelyanov 2c4c7155f2 sysctl: clean from unneeded extern and forward declarations
The do_sysctl_strategy isn't used outside kernel/sysctl.c, so this can be
static and without a prototype in header.

Besides, move this one and parse_table() above their callers and drop the
forward declarations of the latter call.

One more "besides" - fix two checkpatch warnings: space before a ( and an
extra space at the end of a line.

Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Acked-by: David S. Miller <davem@davemloft.net>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Alexey Dobriyan <adobriyan@sw.ru>
Cc: Denis V. Lunev <den@openvz.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-29 08:06:23 -07:00
Adrian Bunk 1a46674b99 include/linux/sysctl.h: remove empty #else
Remove an empty #else.

Signed-off-by: Adrian Bunk <bunk@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-29 08:06:23 -07:00
Serge E. Hallyn 3b7391de67 capabilities: introduce per-process capability bounding set
The capability bounding set is a set beyond which capabilities cannot grow.
 Currently cap_bset is per-system.  It can be manipulated through sysctl,
but only init can add capabilities.  Root can remove capabilities.  By
default it includes all caps except CAP_SETPCAP.

This patch makes the bounding set per-process when file capabilities are
enabled.  It is inherited at fork from parent.  Noone can add elements,
CAP_SETPCAP is required to remove them.

One example use of this is to start a safer container.  For instance, until
device namespaces or per-container device whitelists are introduced, it is
best to take CAP_MKNOD away from a container.

The bounding set will not affect pP and pE immediately.  It will only
affect pP' and pE' after subsequent exec()s.  It also does not affect pI,
and exec() does not constrain pI'.  So to really start a shell with no way
of regain CAP_MKNOD, you would do

	prctl(PR_CAPBSET_DROP, CAP_MKNOD);
	cap_t cap = cap_get_proc();
	cap_value_t caparray[1];
	caparray[0] = CAP_MKNOD;
	cap_set_flag(cap, CAP_INHERITABLE, 1, caparray, CAP_DROP);
	cap_set_proc(cap);
	cap_free(cap);

The following test program will get and set the bounding
set (but not pI).  For instance

	./bset get
		(lists capabilities in bset)
	./bset drop cap_net_raw
		(starts shell with new bset)
		(use capset, setuid binary, or binary with
		file capabilities to try to increase caps)

************************************************************
cap_bound.c
************************************************************
 #include <sys/prctl.h>
 #include <linux/capability.h>
 #include <sys/types.h>
 #include <unistd.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>

 #ifndef PR_CAPBSET_READ
 #define PR_CAPBSET_READ 23
 #endif

 #ifndef PR_CAPBSET_DROP
 #define PR_CAPBSET_DROP 24
 #endif

int usage(char *me)
{
	printf("Usage: %s get\n", me);
	printf("       %s drop <capability>\n", me);
	return 1;
}

 #define numcaps 32
char *captable[numcaps] = {
	"cap_chown",
	"cap_dac_override",
	"cap_dac_read_search",
	"cap_fowner",
	"cap_fsetid",
	"cap_kill",
	"cap_setgid",
	"cap_setuid",
	"cap_setpcap",
	"cap_linux_immutable",
	"cap_net_bind_service",
	"cap_net_broadcast",
	"cap_net_admin",
	"cap_net_raw",
	"cap_ipc_lock",
	"cap_ipc_owner",
	"cap_sys_module",
	"cap_sys_rawio",
	"cap_sys_chroot",
	"cap_sys_ptrace",
	"cap_sys_pacct",
	"cap_sys_admin",
	"cap_sys_boot",
	"cap_sys_nice",
	"cap_sys_resource",
	"cap_sys_time",
	"cap_sys_tty_config",
	"cap_mknod",
	"cap_lease",
	"cap_audit_write",
	"cap_audit_control",
	"cap_setfcap"
};

int getbcap(void)
{
	int comma=0;
	unsigned long i;
	int ret;

	printf("i know of %d capabilities\n", numcaps);
	printf("capability bounding set:");
	for (i=0; i<numcaps; i++) {
		ret = prctl(PR_CAPBSET_READ, i);
		if (ret < 0)
			perror("prctl");
		else if (ret==1)
			printf("%s%s", (comma++) ? ", " : " ", captable[i]);
	}
	printf("\n");
	return 0;
}

int capdrop(char *str)
{
	unsigned long i;

	int found=0;
	for (i=0; i<numcaps; i++) {
		if (strcmp(captable[i], str) == 0) {
			found=1;
			break;
		}
	}
	if (!found)
		return 1;
	if (prctl(PR_CAPBSET_DROP, i)) {
		perror("prctl");
		return 1;
	}
	return 0;
}

int main(int argc, char *argv[])
{
	if (argc<2)
		return usage(argv[0]);
	if (strcmp(argv[1], "get")==0)
		return getbcap();
	if (strcmp(argv[1], "drop")!=0 || argc<3)
		return usage(argv[0]);
	if (capdrop(argv[2])) {
		printf("unknown capability\n");
		return 1;
	}
	return execl("/bin/bash", "/bin/bash", NULL);
}
************************************************************

[serue@us.ibm.com: fix typo]
Signed-off-by: Serge E. Hallyn <serue@us.ibm.com>
Signed-off-by: Andrew G. Morgan <morgan@kernel.org>
Cc: Stephen Smalley <sds@tycho.nsa.gov>
Cc: James Morris <jmorris@namei.org>
Cc: Chris Wright <chrisw@sous-sol.org>
Cc: Casey Schaufler <casey@schaufler-ca.com>a
Signed-off-by: "Serge E. Hallyn" <serue@us.ibm.com>
Tested-by: Jiri Slaby <jirislaby@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-02-05 09:44:20 -08:00
Eric Dumazet 29e75252da [IPV4] route cache: Introduce rt_genid for smooth cache invalidation
Current ip route cache implementation is not suited to large caches.

We can consume a lot of CPU when cache must be invalidated, since we
currently need to evict all cache entries, and this eviction is
sometimes asynchronous. min_delay & max_delay can somewhat control this
asynchronism behavior, but whole thing is a kludge, regularly triggering
infamous soft lockup messages. When entries are still in use, this also
consumes a lot of ram, filling dst_garbage.list.

A better scheme is to use a generation identifier on each entry,
so that cache invalidation can be performed by changing the table
identifier, without having to scan all entries.
No more delayed flushing, no more stalling when secret_interval expires.

Invalidated entries will then be freed at GC time (controled by
ip_rt_gc_timeout or stress), or when an invalidated entry is found
in a chain when an insert is done.
Thus we keep a normal equilibrium.

This patch :
- renames rt_hash_rnd to rt_genid (and makes it an atomic_t)
- Adds a new rt_genid field to 'struct rtable' (filling a hole on 64bit)
- Checks entry->rt_genid at appropriate places :
2008-01-31 19:28:27 -08:00
Eric W. Biederman e51b6ba077 sysctl: Infrastructure for per namespace sysctls
This patch implements the basic infrastructure for per namespace sysctls.

A list of lists of sysctl headers is added, allowing each namespace to have
it's own list of sysctl headers.

Each list of sysctl headers has a lookup function to find the first
sysctl header in the list, allowing the lists to have a per namespace
instance.

register_sysct_root is added to tell sysctl.c about additional
lists of sysctl_headers.  As all of the users are expected to be in
kernel no unregister function is provided.

sysctl_head_next is updated to walk through the list of lists.

__register_sysctl_paths is added to add a new sysctl table on
a non-default sysctl list.

The only intrusive part of this patch is propagating the information
to decided which list of sysctls to use for sysctl_check_table.

Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Cc: Serge Hallyn <serue@us.ibm.com>
Cc: Daniel Lezcano <dlezcano@fr.ibm.com>
Cc: Cedric Le Goater <clg@fr.ibm.com>
Cc: Pavel Emelyanov <xemul@openvz.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
2008-01-28 14:55:17 -08:00
Eric W. Biederman 23eb06de7d sysctl: Remember the ctl_table we passed to register_sysctl_paths
By doing this we allow users of register_sysctl_paths that build
and dynamically allocate their ctl_table to be simpler.  This allows
them to just remember the ctl_table_header returned from
register_sysctl_paths from which they can now find the
ctl_table array they need to free.

Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Cc: Serge Hallyn <serue@us.ibm.com>
Cc: Daniel Lezcano <dlezcano@fr.ibm.com>
Cc: Cedric Le Goater <clg@fr.ibm.com>
Cc: Pavel Emelyanov <xemul@openvz.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
2008-01-28 14:55:17 -08:00
Eric W. Biederman 29e796fd4d sysctl: Add register_sysctl_paths function
There are a number of modules that register a sysctl table
somewhere deeply nested in the sysctl hierarchy, such as
fs/nfs, fs/xfs, dev/cdrom, etc.

They all specify several dummy ctl_tables for the path name.
This patch implements register_sysctl_path that takes
an additional path name, and makes up dummy sysctl nodes
for each component.

This patch was originally written by Olaf Kirch and
brought to my attention and reworked some by Olaf Hering.
I have changed a few additional things so the bugs are mine.

After converting all of the easy callers Olaf Hering observed
allyesconfig ARCH=i386, the patch reduces the final binary size by 9369 bytes.

.text +897
.data -7008

   text    data     bss     dec     hex filename
   26959310        4045899 4718592 35723801        2211a19 ../vmlinux-vanilla
   26960207        4038891 4718592 35717690        221023a ../O-allyesconfig/vmlinux

So this change is both a space savings and a code simplification.

CC: Olaf Kirch <okir@suse.de>
CC: Olaf Hering <olaf@aepfle.de>
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Cc: Serge Hallyn <serue@us.ibm.com>
Cc: Daniel Lezcano <dlezcano@fr.ibm.com>
Cc: Cedric Le Goater <clg@fr.ibm.com>
Cc: Pavel Emelyanov <xemul@openvz.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
2008-01-28 14:55:16 -08:00
Heiko Carstens 37e3a6ac5a [S390] appldata: remove unused binary sysctls.
Remove binary sysctls that never worked due to missing strategy functions.

Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: Gerald Schaefer <geraldsc@de.ibm.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2007-11-20 11:13:45 +01:00
Heiko Carstens 43ebbf119a [S390] cmm: remove unused binary sysctls.
Remove binary sysctls that never worked due to missing strategy functions.

Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2007-11-20 11:13:45 +01:00
Eric W. Biederman fc6cd25b73 sysctl: Error on bad sysctl tables
After going through the kernels sysctl tables several times it has become
clear that code review and testing is just not effective in prevent
problematic sysctl tables from being used in the stable kernel.  I certainly
can't seem to fix the problems as fast as they are introduced.

Therefore this patch adds sysctl_check_table which is called when a sysctl
table is registered and checks to see if we have a problematic sysctl table.

The biggest part of the code is the table of valid binary sysctl entries, but
since we have frozen our set of binary sysctls this table should not need to
change, and it makes it much easier to detect when someone unintentionally
adds a new binary sysctl value.

As best as I can determine all of the several hundred errors spewed on boot up
now are legitimate.

[bunk@kernel.org: kernel/sysctl_check.c must #include <linux/string.h>]
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Cc: Alexey Dobriyan <adobriyan@sw.ru>
Signed-off-by: Adrian Bunk <bunk@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-18 14:37:23 -07:00
Eric W. Biederman f429cd37a2 sysctl: properly register the irda binary sysctl numbers
Grumble.  These numbers should have been in sysctl.h from the beginning if we
ever expected anyone to use them.  Oh well put them there now so we can find
them and make maintenance easier.

Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Acked-by: Samuel Ortiz <samuel@sortiz.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-18 14:37:23 -07:00
Eric W. Biederman 49a0c45833 sysctl: Factor out sysctl_data.
There as been no easy way to wrap the default sysctl strategy routine except
for returning 0.  Which is not always what we want.  The few instances I have
seen that want different behaviour have written their own version of
sysctl_data.  While not too hard it is unnecessary code and has the potential
for extra bugs.

So to make these situations easier and make that part of sysctl more symetric
I have factord sysctl_data out of do_sysctl_strategy and exported as a
function everyone can use.

Further having sysctl_data be an explicit function makes checking for badly
formed sysctl tables much easier.

Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Cc: Alexey Dobriyan <adobriyan@sw.ru>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-18 14:37:22 -07:00
Eric W. Biederman d8217f076b sysctl core: Stop using the unnecessary ctl_table typedef
In sysctl.h the typedef struct ctl_table ctl_table violates coding style isn't
needed and is a bit of a nuisance because it makes it harder to recognize
ctl_table is a type name.

So this patch removes it from the generic sysctl code.  Hopefully I will have
enough energy to send the rest of my patches will follow and to remove it from
the rest of the kernel.

Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Cc: Alexey Dobriyan <adobriyan@sw.ru>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-18 14:37:22 -07:00
Alexey Dobriyan 0d0ed42e5c Add CTL_PROC back
commit eab03ac7bd aka
"[PATCH] Get rid of /proc/sys/proc" was good commit except strace(1) compile
breakage it introduced:

	system.c:1581: error: 'CTL_PROC' undeclared here (not in a function)

So, add dummy enum back.

Signed-off-by: Alexey Dobriyan <adobriyan@sw.ru>
Cc: Stephen Hemminger <shemminger@osdl.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-31 15:39:39 -07:00
Michael Milner 516299d2f5 [NETFILTER]: bridge-nf: filter bridged IPv4/IPv6 encapsulated in pppoe traffic
The attached patch by Michael Milner adds support for using iptables and
ip6tables on bridged traffic encapsulated in ppoe frames, similar to
what's already supported for vlan.

Signed-off-by: Michael Milner <milner@blissisland.ca>
Signed-off-by: Bart De Schuymer <bdschuym@pandora.be>
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2007-04-25 22:28:57 -07:00
Stephen Hemminger a2a316fd06 [NET]: Replace CONFIG_NET_DEBUG with sysctl.
Covert network warning messages from a compile time to runtime choice.
Removes kernel config option and replaces it with new /proc/sys/net/core/warnings.

Signed-off-by: Stephen Hemminger <shemminger@linux-foundation.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2007-04-25 22:24:05 -07:00
Ilpo Järvinen 3cfe3baaf0 [TCP]: Add two new spurious RTO responses to FRTO
New sysctl tcp_frto_response is added to select amongst these
responses:
	- Rate halving based; reuses CA_CWR state (default)
	- Very conservative; used to be the only one available (=1)
	- Undo cwr; undoes ssthresh and cwnd reductions (=2)

The response with rate halving requires a new parameter to
tcp_enter_cwr because FRTO has already reduced ssthresh and
doing a second reduction there has to be prevented. In addition,
to keep things nice on 80 cols screen, a local variable was
added.

Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi>
Signed-off-by: David S. Miller <davem@davemloft.net>
2007-04-25 22:23:23 -07:00
John Heffner 886236c124 [TCP]: Add RFC3742 Limited Slow-Start, controlled by variable sysctl_tcp_max_ssthresh.
Signed-off-by: John Heffner <jheffner@psc.edu>
Signed-off-by: David S. Miller <davem@davemloft.net>
2007-04-25 22:23:19 -07:00
YOSHIFUJI Hideaki 0bcbc92629 [IPV6]: Disallow RH0 by default.
A security issue is emerging.  Disallow Routing Header Type 0 by default
as we have been doing for IPv4.
Note: We allow RH2 by default because it is harmless.

Signed-off-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2007-04-24 14:58:30 -07:00
Eric W. Biederman 3fbfa98112 [PATCH] sysctl: remove the proc_dir_entry member for the sysctl tables
It isn't needed anymore, all of the users are gone, and all of the ctl_table
initializers have been converted to use explicit names of the fields they are
initializing.

[akpm@osdl.org: NTFS fix]
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Acked-by: Stephen Smalley <sds@tycho.nsa.gov>
Cc: James Morris <jmorris@namei.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-02-14 08:10:00 -08:00
Eric W. Biederman d912b0cc1a [PATCH] sysctl: add a parent entry to ctl_table and set the parent entry
Add a parent entry into the ctl_table so you can walk the list of parents and
find the entire path to a ctl_table entry.

Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Cc: Stephen Smalley <sds@tycho.nsa.gov>
Cc: James Morris <jmorris@namei.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-02-14 08:10:00 -08:00
Eric W. Biederman 77b14db502 [PATCH] sysctl: reimplement the sysctl proc support
With this change the sysctl inodes can be cached and nothing needs to be done
when removing a sysctl table.

For a cost of 2K code we will save about 4K of static tables (when we remove
de from ctl_table) and 70K in proc_dir_entries that we will not allocate, or
about half that on a 32bit arch.

The speed feels about the same, even though we can now cache the sysctl
dentries :(

We get the core advantage that we don't need to have a 1 to 1 mapping between
ctl table entries and proc files.  Making it possible to have /proc/sys vary
depending on the namespace you are in.  The currently merged namespaces don't
have an issue here but the network namespace under /proc/sys/net needs to have
different directories depending on which network adapters are visible.  By
simply being a cache different directories being visible depending on who you
are is trivial to implement.

[akpm@osdl.org: fix uninitialised var]
[akpm@osdl.org: fix ARM build]
[bunk@stusta.de: make things static]
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Cc: Russell King <rmk@arm.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-02-14 08:10:00 -08:00
Eric W. Biederman 1ff007eb8e [PATCH] sysctl: allow sysctl_perm to be called from outside of sysctl.c
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-02-14 08:09:59 -08:00
Eric W. Biederman 805b5d5e06 [PATCH] sysctl: factor out sysctl_head_next from do_sysctl
The current logic to walk through the list of sysctl table headers is slightly
painful and implement in a way it cannot be used by code outside sysctl.c

I am in the process of implementing a version of the sysctl proc support that
instead of using the proc generic non-caching monster, just uses the existing
sysctl data structure as backing store for building the dcache entries and for
doing directory reads.  To use the existing data structures however I need a
way to get at them.

[akpm@osdl.org: warning fix]
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-02-14 08:09:59 -08:00
Eric W. Biederman 0b4d414714 [PATCH] sysctl: remove insert_at_head from register_sysctl
The semantic effect of insert_at_head is that it would allow new registered
sysctl entries to override existing sysctl entries of the same name.  Which is
pain for caching and the proc interface never implemented.

I have done an audit and discovered that none of the current users of
register_sysctl care as (excpet for directories) they do not register
duplicate sysctl entries.

So this patch simply removes the support for overriding existing entries in
the sys_sysctl interface since no one uses it or cares and it makes future
enhancments harder.

Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Acked-by: Ralf Baechle <ralf@linux-mips.org>
Acked-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Russell King <rmk@arm.linux.org.uk>
Cc: David Howells <dhowells@redhat.com>
Cc: "Luck, Tony" <tony.luck@intel.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Andi Kleen <ak@muc.de>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Corey Minyard <minyard@acm.org>
Cc: Neil Brown <neilb@suse.de>
Cc: "John W. Linville" <linville@tuxdriver.com>
Cc: James Bottomley <James.Bottomley@steeleye.com>
Cc: Jan Kara <jack@ucw.cz>
Cc: Trond Myklebust <trond.myklebust@fys.uio.no>
Cc: Mark Fasheh <mark.fasheh@oracle.com>
Cc: David Chinner <dgc@sgi.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Patrick McHardy <kaber@trash.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-02-14 08:09:59 -08:00
Eric W. Biederman 6703ddfcce [PATCH] sysctl: remove support for CTL_ANY
There are currently no users in the kernel for CTL_ANY and it only has effect
on the binary interface which is practically unused.

So this complicates sysctl lookups for no good reason so just remove it.

Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-02-14 08:09:59 -08:00
Eric W. Biederman 0e03036c97 [PATCH] sysctl: register the ocfs2 sysctl numbers
ocfs2 was did not have the binary number it uses under CTL_FS registered in
sysctl.h.  Register it to avoid future conflicts, and change the name of the
definition to be in line with the rest of the sysctl numbers.

Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Acked-by: Mark Fasheh <mark.fasheh@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-02-14 08:09:58 -08:00
Eric W. Biederman 59fc5313b3 [PATCH] sysctl: register the sysctl number used by the arlan driver
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Cc: "John W. Linville" <linville@tuxdriver.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-02-14 08:09:57 -08:00
Eric W. Biederman feceb63ec5 [PATCH] sysctl: s390: move sysctl definitions to sysctl.h
We need to have the the definition of all top level sysctl directories
registers in sysctl.h so we don't conflict by accident and cause abi problems.

Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Acked-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-02-14 08:09:57 -08:00
Eric W. Biederman 77f6dfb129 [PATCH] sysctl: move CTL_FRV into sysctl.h where it belongs
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Acked-by: David Howells <dhowells@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-02-14 08:09:56 -08:00
Eric W. Biederman 462591b886 [PATCH] sysctl: move CTL_PM into sysctl.h where it belongs
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-02-14 08:09:56 -08:00
Eric W. Biederman 50d851f722 [PATCH] sysctl: move CTL_SUNRPC to sysctl.h where it belongs
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Cc: Trond Myklebust <trond.myklebust@fys.uio.no>
Cc: Neil Brown <neilb@cse.unsw.edu.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-02-14 08:09:55 -08:00
Andrew Hendry 39e21c0d34 [X.25]: Adds /proc/sys/net/x25/x25_forward to control forwarding.
echo "1" > /proc/sys/net/x25/x25_forward 
To turn on x25_forwarding, defaults to off
Requires the previous patch.

Signed-off-by: Andrew Hendry <andrew.hendry@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2007-02-08 13:34:36 -08:00
Rolf Eike Beer 93aec20400 Remove duplicate "have to" in comment
Introduced in commit 7cc13edc13.

Signed-off-by: Rolf Eike Beer <eike-kernel@sf-tec.de>
Acked-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: Adrian Bunk <bunk@stusta.de>
2006-12-12 19:23:02 +01:00
Alexey Dobriyan 1f29bcd739 [PATCH] sysctl: remove unused "context" param
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Andi Kleen <ak@suse.de>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: David Howells <dhowells@redhat.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-10 09:55:41 -08:00
Gerrit Renker 4384260443 [DCCP]: Remove allocation of sysctl numbers
This is in response to a request sent earlier by Eric W. Biederman
and replaces all sysctl numbers for net.dccp.default with CTL_UNNUMBERED.

It has been tested to compile and to work.

Commiter note: I've removed the use of CTL_UNNUMBERED, not setting .ctl_name
               sets it to 0, that is the what CTL_UNNUMBERED is, reason is
               to avoid unneeded source code cluttering.

Signed-off-by: Gerrit Renker  <gerrit@erg.abdn.ac.uk>
Signed-off-by: Ian McDonald <ian.mcdonald@jandi.co.nz>
Signed-off-by: Arnaldo Carvalho de Melo <acme@mandriva.com>
2006-12-02 21:30:56 -08:00
Ian McDonald 82e3ab9dbe [DCCP]: Adds the tx buffer sysctls
This one got lost on the way from Ian to Gerrit to me, fix it.

Signed-off-by: Ian McDonald <ian.mcdonald@jandi.co.nz>
Signed-off-by: Arnaldo Carvalho de Melo <acme@mandriva.com>
2006-12-02 21:24:42 -08:00
Gerrit Renker 2e2e9e92bd [DCCP]: Add sysctls to control retransmission behaviour
This adds 3 sysctls which govern the retransmission behaviour of DCCP control
packets (3way handshake, feature negotiation).

It removes 4 FIXMEs from the code.

The close resemblance of sysctl variables to their TCP analogues is emphasised
not only by their name, but also by giving them the same initial values.
This is useful since there is not much practical experience with DCCP yet.

Furthermore, with regard to the previous patch, it is now possible to limit
the number of keepalive-Responses by setting net.dccp.default.request_retries
(also a bit like in TCP).

Lastly, added documentation of all existing DCCP sysctls.

Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk>
Signed-off-by: Arnaldo Carvalho de Melo <acme@mandriva.com>
2006-12-02 21:22:18 -08:00
Stephen Hemminger ce7bc3bf15 [TCP]: Restrict congestion control choices.
Allow normal users to only choose among a restricted set of congestion
control choices.  The default is reno and what ever has been configured
as default. But the policy can be changed by administrator at any time.

For example, to allow any choice:
    cp /proc/sys/net/ipv4/tcp_available_congestion_control \
       /proc/sys/net/ipv4/tcp_allowed_congestion_control

Signed-off-by: Stephen Hemminger <shemminger@osdl.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2006-12-02 21:21:49 -08:00
Stephen Hemminger 3ff825b28d [TCP]: Add tcp_available_congestion_control sysctl.
Create /proc/sys/net/ipv4/tcp_available_congestion_control
that reflects currently available TCP choices.

Signed-off-by: Stephen Hemminger <shemminger@osdl.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2006-12-02 21:21:48 -08:00
Eric W. Biederman 7cc13edc13 [PATCH] sysctl: implement CTL_UNNUMBERED
This patch takes the CTL_UNNUMBERD concept from NFS and makes it available to
all new sysctl users.

At the same time the sysctl binary interface maintenance documentation is
updated to mention and to describe what is needed to successfully maintain the
sysctl binary interface.

Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Acked-by: Alan Cox <alan@redhat.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-11-06 01:46:23 -08:00
Eric W. Biederman d99f160ac5 [PATCH] sysctl: allow a zero ctl_name in the middle of a sysctl table
Since it is becoming clear that there are just enough users of the binary
sysctl interface that completely removing the binary interface from the kernel
will not be an option for foreseeable future, we need to find a way to address
the sysctl maintenance issues.

The basic problem is that sysctl requires one central authority to allocate
sysctl numbers, or else conflicts and ABI breakage occur.  The proc interface
to sysctl does not have that problem, as names are not densely allocated.

By not terminating a sysctl table until I have neither a ctl_name nor a
procname, it becomes simple to add sysctl entries that don't show up in the
binary sysctl interface.  Which allows people to avoid allocating a binary
sysctl value when not needed.

I have audited the kernel code and in my reading I have not found a single
sysctl table that wasn't terminated by a completely zero filled entry.  So
this change in behavior should not affect anything.

I think this mechanism eases the pain enough that combined with a little
disciple we can solve the reoccurring sysctl ABI breakage.

Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Acked-by: Alan Cox <alan@redhat.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-11-06 01:46:23 -08:00
Linus Torvalds b278240839 Merge branch 'for-linus' of git://one.firstfloor.org/home/andi/git/linux-2.6
* 'for-linus' of git://one.firstfloor.org/home/andi/git/linux-2.6: (225 commits)
  [PATCH] Don't set calgary iommu as default y
  [PATCH] i386/x86-64: New Intel feature flags
  [PATCH] x86: Add a cumulative thermal throttle event counter.
  [PATCH] i386: Make the jiffies compares use the 64bit safe macros.
  [PATCH] x86: Refactor thermal throttle processing
  [PATCH] Add 64bit jiffies compares (for use with get_jiffies_64)
  [PATCH] Fix unwinder warning in traps.c
  [PATCH] x86: Allow disabling early pci scans with pci=noearly or disallowing conf1
  [PATCH] x86: Move direct PCI scanning functions out of line
  [PATCH] i386/x86-64: Make all early PCI scans dependent on CONFIG_PCI
  [PATCH] Don't leak NT bit into next task
  [PATCH] i386/x86-64: Work around gcc bug with noreturn functions in unwinder
  [PATCH] Fix some broken white space in ia32_signal.c
  [PATCH] Initialize argument registers for 32bit signal handlers.
  [PATCH] Remove all traces of signal number conversion
  [PATCH] Don't synchronize time reading on single core AMD systems
  [PATCH] Remove outdated comment in x86-64 mmconfig code
  [PATCH] Use string instructions for Core2 copy/clear
  [PATCH] x86: - restore i8259A eoi status on resume
  [PATCH] i386: Split multi-line printk in oops output.
  ...
2006-09-26 13:07:55 -07:00
Christoph Lameter 0ff38490c8 [PATCH] zone_reclaim: dynamic slab reclaim
Currently one can enable slab reclaim by setting an explicit option in
/proc/sys/vm/zone_reclaim_mode.  Slab reclaim is then used as a final
option if the freeing of unmapped file backed pages is not enough to free
enough pages to allow a local allocation.

However, that means that the slab can grow excessively and that most memory
of a node may be used by slabs.  We have had a case where a machine with
46GB of memory was using 40-42GB for slab.  Zone reclaim was effective in
dealing with pagecache pages.  However, slab reclaim was only done during
global reclaim (which is a bit rare on NUMA systems).

This patch implements slab reclaim during zone reclaim.  Zone reclaim
occurs if there is a danger of an off node allocation.  At that point we

1. Shrink the per node page cache if the number of pagecache
   pages is more than min_unmapped_ratio percent of pages in a zone.

2. Shrink the slab cache if the number of the nodes reclaimable slab pages
   (patch depends on earlier one that implements that counter)
   are more than min_slab_ratio (a new /proc/sys/vm tunable).

The shrinking of the slab cache is a bit problematic since it is not node
specific.  So we simply calculate what point in the slab we want to reach
(current per node slab use minus the number of pages that neeed to be
allocated) and then repeately run the global reclaim until that is
unsuccessful or we have reached the limit.  I hope we will have zone based
slab reclaim at some point which will make that easier.

The default for the min_slab_ratio is 5%

Also remove the slab option from /proc/sys/vm/zone_reclaim_mode.

[akpm@osdl.org: cleanups]
Signed-off-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-09-26 08:48:51 -07:00