procfs: drop vmtruncate

Removed vmtruncate

Signed-off-by: Marco Stornelli <marco.stornelli@gmail.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

sysctl: Pass useful parameters to sysctl permissions

- Current is implicitly avaiable so passing current->nsproxy isn't useful.
- The ctl_table_header is needed to find how the sysctl table is conne

sysctl: Pass useful parameters to sysctl permissions

- Current is implicitly avaiable so passing current->nsproxy isn't useful.
- The ctl_table_header is needed to find how the sysctl table is connected
to the rest of sysctl.
- ctl_table_root is avaiable in the ctl_table_header so no need to it.

With these changes it becomes possible to write a version of
net_sysctl_permission that takes into account the network namespace of
the sysctl table, an important feature in extending the user namespace.

Acked-by: Serge Hallyn <serge.hallyn@canonical.com>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

show more ...

rbtree: fix incorrect rbtree node insertion in fs/proc/proc_sysctl.c

The recently added code to use rbtrees in sysctl did not follow the proper
rbtree interface on insertion - it was calling rb_link

rbtree: fix incorrect rbtree node insertion in fs/proc/proc_sysctl.c

The recently added code to use rbtrees in sysctl did not follow the proper
rbtree interface on insertion - it was calling rb_link_node() which
inserts a new node into the binary tree, but missed the call to
rb_insert_color() which properly balances the rbtree and establishes all
expected rbtree invariants.

I found out about this only because faulty commit also used
rb_init_node(), which I am removing within this patchset. But I think
it's an easy mistake to make, and it makes me wonder if we should change
the rbtree API so that insertions would be done with a single rb_insert()
call (even if its implementation could still inline the rb_link_node()
part and call a private __rb_insert_color function to do the rebalancing).

Signed-off-by: Michel Lespinasse <walken@google.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Acked-by: David Woodhouse <David.Woodhouse@intel.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Daniel Santos <daniel.santos@pobox.com>
Cc: Jens Axboe <axboe@kernel.dk>
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>

show more ...

rbtree: empty nodes have no color

Empty nodes have no color. We can make use of this property to simplify
the code emitted by the RB_EMPTY_NODE and RB_CLEAR_NODE macros. Also,
we can get rid of th

rbtree: empty nodes have no color

Empty nodes have no color. We can make use of this property to simplify
the code emitted by the RB_EMPTY_NODE and RB_CLEAR_NODE macros. Also,
we can get rid of the rb_init_node function which had been introduced by
commit 88d19cf37952 ("timers: Add rb_init_node() to allow for stack
allocated rb nodes") to avoid some issue with the empty node's color not
being initialized.

I'm not sure what the RB_EMPTY_NODE checks in rb_prev() / rb_next() are
doing there, though. axboe introduced them in commit 10fd48f2376d
("rbtree: fixed reversed RB_EMPTY_NODE and rb_next/prev"). The way I
see it, the 'empty node' abstraction is only used by rbtree users to
flag nodes that they haven't inserted in any rbtree, so asking the
predecessor or successor of such nodes doesn't make any sense.

One final rb_init_node() caller was recently added in sysctl code to
implement faster sysctl name lookups. This code doesn't make use of
RB_EMPTY_NODE at all, and from what I could see it only called
rb_init_node() under the mistaken assumption that such initialization was
required before node insertion.

[sfr@canb.auug.org.au: fix net/ceph/osd_client.c build]
Signed-off-by: Michel Lespinasse <walken@google.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Acked-by: David Woodhouse <David.Woodhouse@intel.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Daniel Santos <daniel.santos@pobox.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: John Stultz <john.stultz@linaro.org>
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

show more ...

proc_sysctl.c: use BUG_ON instead of BUG

The use of if (!head) BUG(); can be replaced with the single line
BUG_ON(!head).

Signed-off-by: Prasad Joshi <prasadjoshi.linux@gmail.com>
Signed-off-by: An

proc_sysctl.c: use BUG_ON instead of BUG

The use of if (!head) BUG(); can be replaced with the single line
BUG_ON(!head).

Signed-off-by: Prasad Joshi <prasadjoshi.linux@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

show more ...

fs/proc: fix potential unregister_sysctl_table hang

The unregister_sysctl_table() function hangs if all references to its
ctl_table_header structure are not dropped.

This can happen sometimes becau

fs/proc: fix potential unregister_sysctl_table hang

The unregister_sysctl_table() function hangs if all references to its
ctl_table_header structure are not dropped.

This can happen sometimes because of a leak in proc_sys_lookup():
proc_sys_lookup() gets a reference to the table via lookup_entry(), but
it does not release it when a subsequent call to sysctl_follow_link()
fails.

This patch fixes this leak by making sure the reference is always
dropped on return.

See also commit 076c3eed2c31 ("sysctl: Rewrite proc_sys_lookup
introducing find_entry and lookup_entry") which reorganized this code in
3.4.

Tested in Linux 3.4.4.

Signed-off-by: Francesco Ruggeri <fruggeri@aristanetworks.com>
Cc: stable@vger.kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

show more ...

stop passing nameidata to ->lookup()

Just the flags; only NFS cares even about that, but there are
legitimate uses for such argument. And getting rid of that
completely would require splitting ->lo

stop passing nameidata to ->lookup()

Just the flags; only NFS cares even about that, but there are
legitimate uses for such argument. And getting rid of that
completely would require splitting ->lookup() into a couple
of methods (at least), so let's leave that alone for now...

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

show more ...

stop passing nameidata * to ->d_revalidate()

Just the lookup flags. Die, bastard, die...

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

userns: Convert sysctl permission checks to use kuid and kgids.

Acked-by: Serge Hallyn <serge.hallyn@canonical.com>
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>

sysctl: protect poll() in entries that may go away

Protect code accessing ctl_table by grabbing the header with grab_header()
and after releasing with sysctl_head_finish(). This is needed if poll()

sysctl: protect poll() in entries that may go away

Protect code accessing ctl_table by grabbing the header with grab_header()
and after releasing with sysctl_head_finish(). This is needed if poll()
is called in entries created by modules: currently only hostname and
domainname support poll(), but this bug may be triggered when/if modules
use it and if user called poll() in a file that doesn't support it.

Dave Jones reported the following when using a syscall fuzzer while
hibernating/resuming:

RIP: 0010:[<ffffffff81233e3e>] [<ffffffff81233e3e>] proc_sys_poll+0x4e/0x90
RAX: 0000000000000145 RBX: ffff88020cab6940 RCX: 0000000000000000
RDX: ffffffff81233df0 RSI: 6b6b6b6b6b6b6b6b RDI: ffff88020cab6940
[ ... ]
Code: 00 48 89 fb 48 89 f1 48 8b 40 30 4c 8b 60 e8 b8 45 01 00 00 49 83
7c 24 28 00 74 2e 49 8b 74 24 30 48 85 f6 74 24 48 85 c9 75 32 <8b> 16
b8 45 01 00 00 48 63 d2 49 39 d5 74 10 8b 06 48 98 48 89

If an entry goes away while we are polling() it, ctl_table may not exist
anymore.

Reported-by: Dave Jones <davej@redhat.com>
Signed-off-by: Lucas De Marchi <lucas.demarchi@profusion.mobi>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: stable@vger.kernel.org
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>

show more ...

security: trim security.h

Trim security.h

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: James Morris <jmorris@namei.org>

sysctl: Don't call sysctl_follow_link unless we are a link.

There are no functional changes. Just code motion to make it
clear that we don't follow a link between sysctl roots unless the
directory

sysctl: Don't call sysctl_follow_link unless we are a link.

There are no functional changes. Just code motion to make it
clear that we don't follow a link between sysctl roots unless the
directory entry actually is a link.

Suggested-by: Lucian Adrian Grijincu <lucian.grijincu@gmail.com>
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>

show more ...

sysctl: Comments to make the code clearer.

Document get_subdir and that find_subdir alwasy takes a reference.

Suggested-by: Lucian Adrian Grijincu <lucian.grijincu@gmail.com>
Signed-off-by: Eric W

sysctl: Comments to make the code clearer.

Document get_subdir and that find_subdir alwasy takes a reference.

Suggested-by: Lucian Adrian Grijincu <lucian.grijincu@gmail.com>
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>

show more ...

sysctl: Correct error return from get_subdir

When insert_header fails ensure we return the proper error value
from get_subdir. In practice nothing cares, but there is no
need to be sloppy.

Reporte

sysctl: Correct error return from get_subdir

When insert_header fails ensure we return the proper error value
from get_subdir. In practice nothing cares, but there is no
need to be sloppy.

Reported-by: Lucian Adrian Grijincu <lucian.grijincu@gmail.com>
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>

show more ...

sysctl: An easier to read version of find_subdir

Suggested-by: Lucian Adrian Grijincu <lucian.grijincu@gmail.com>
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>

sysctl: fix memset parameters in setup_sysctl_set()

The current code is a nop.

Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>

sysctl: remove an unused variable

"links" is never used, so we can remove it.

Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>

sysctl: Add register_sysctl for normal sysctl users

The plan is to convert all callers of register_sysctl_table
and register_sysctl_paths to register_sysctl. The interface
to register_sysctl is eno

sysctl: Add register_sysctl for normal sysctl users

The plan is to convert all callers of register_sysctl_table
and register_sysctl_paths to register_sysctl. The interface
to register_sysctl is enough nicer this should make the callers
a bit more readable. Additionally after the conversion the
230 lines of backwards compatibility can be removed.

Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>

show more ...

sysctl: Index sysctl directories with rbtrees.

One of the most important jobs of sysctl is to export network stack
tunables. Several of those tunables are per network device. In
several instances

sysctl: Index sysctl directories with rbtrees.

One of the most important jobs of sysctl is to export network stack
tunables. Several of those tunables are per network device. In
several instances people are running with 1000+ network devices in
there network stacks, which makes the simple per directory linked list
in sysctl a scaling bottleneck. Replace O(N^2) sysctl insertion and
lookup times with O(NlogN) by using an rbtree to index the sysctl
directories.

Benchmark before:
make-dummies 0 999 -> 0.32s
rmmod dummy -> 0.12s
make-dummies 0 9999 -> 1m17s
rmmod dummy -> 17s

Benchmark after:
make-dummies 0 999 -> 0.074s
rmmod dummy -> 0.070s
make-dummies 0 9999 -> 3.4s
rmmod dummy -> 0.44s

Benchmark after (without dev_snmp6):
make-dummies 0 9999 -> 0.75s
rmmod dummy -> 0.44s
make-dummies 0 99999 -> 11s
rmmod dummy -> 4.3s

At 10,000 dummy devices the bottleneck becomes the time to add and
remove the files under /proc/sys/net/dev_snmp6. I have commented
out the code that adds and removes files under /proc/sys/net/dev_snmp6
and taken measurments of creating and destroying 100,000 dummies to
verify the sysctl continues to scale.

Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>

show more ...

sysctl: Make the header lists per directory.

Slightly enhance efficiency and clarity of the code by making the
header list per directory instead of per set.

Benchmark before:
make-dummies 0 999

sysctl: Make the header lists per directory.

Slightly enhance efficiency and clarity of the code by making the
header list per directory instead of per set.

Benchmark before:
make-dummies 0 999 -> 0.63s
rmmod dummy -> 0.12s
make-dummies 0 9999 -> 2m35s
rmmod dummy -> 18s

Benchmark after:
make-dummies 0 999 -> 0.32s
rmmod dummy -> 0.12s
make-dummies 0 9999 -> 1m17s
rmmod dummy -> 17s

Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>

show more ...

sysctl: Move sysctl_check_dups into insert_header

Simplify the callers of insert_header by removing explicit calls to check
for duplicates and instead have insert_header do the work.

This makes the

sysctl: Move sysctl_check_dups into insert_header

Simplify the callers of insert_header by removing explicit calls to check
for duplicates and instead have insert_header do the work.

This makes the code slightly more maintainable by enabling changes to
data structures where the insertion of new entries without duplicate
suppression is not possible.

There is not always a convenient path string where insert_header
is called so modify sysctl_check_dups to use sysctl_print_dir
when printing the full path when a duplicate is discovered.

Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>

show more ...

sysctl: Modify __register_sysctl_paths to take a set instead of a root and an nsproxy

An nsproxy argument here has always been awkard and now the nsproxy argument
is completely unnecessary so remove

sysctl: Modify __register_sysctl_paths to take a set instead of a root and an nsproxy

An nsproxy argument here has always been awkard and now the nsproxy argument
is completely unnecessary so remove it, replacing it with the set we want
the registered tables to show up in.

Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>

show more ...

sysctl: Replace root_list with links between sysctl_table_sets.

Piecing together directories by looking first in one directory
tree, than in another directory tree and finally in a third
directory t

sysctl: Replace root_list with links between sysctl_table_sets.

Piecing together directories by looking first in one directory
tree, than in another directory tree and finally in a third
directory tree makes it hard to verify that some directory
entries are not multiply defined and makes it hard to create
efficient implementations the sysctl filesystem.

Replace the sysctl wide list of roots with autogenerated
links from the core sysctl directory tree to the other
sysctl directory trees.

This simplifies sysctl directory reading and lookups as now
only entries in a single sysctl directory tree need to be
considered.

Benchmark before:
make-dummies 0 999 -> 0.44s
rmmod dummy -> 0.065s
make-dummies 0 9999 -> 1m36s
rmmod dummy -> 0.4s

Benchmark after:
make-dummies 0 999 -> 0.63s
rmmod dummy -> 0.12s
make-dummies 0 9999 -> 2m35s
rmmod dummy -> 18s

The slowdown is caused by the lookups used in insert_headers
and put_links to see if we need to add links or remove links.

Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>

show more ...

sysctl: Add sysctl_print_dir and use it in get_subdir

When there are errors it is very nice to know the full sysctl path.
Add a simple function that computes the sysctl path and prints it
out.

Sign

sysctl: Add sysctl_print_dir and use it in get_subdir

When there are errors it is very nice to know the full sysctl path.
Add a simple function that computes the sysctl path and prints it
out.

Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>

show more ...

sysctl: Stop requiring explicit management of sysctl directories

Simplify the code and the sysctl semantics by autogenerating
sysctl directories when a sysctl table is registered that needs
the dire

sysctl: Stop requiring explicit management of sysctl directories

Simplify the code and the sysctl semantics by autogenerating
sysctl directories when a sysctl table is registered that needs
the directories and autodeleting the directories when there are
no more sysctl tables registered that need them.

Autogenerating directories keeps sysctl tables from depending
on each other, removing all of the arcane register/unregister
ordering constraints and makes it impossible to get the order
wrong when reigsering and unregistering sysctl tables.

Autogenerating directories yields one unique entity that dentries
can point to, retaining the current effective use of the dcache.

Add struct ctl_dir as the type of these new autogenerated
directories.

The attached_by and attached_to fields in ctl_table_header are
removed as they are no longer needed.

The child field in ctl_table is no longer needed by the core of
the sysctl code. ctl_table.child can be removed once all of the
existing users have been updated.

Benchmark before:
make-dummies 0 999 -> 0.7s
rmmod dummy -> 0.07s
make-dummies 0 9999 -> 1m10s
rmmod dummy -> 0.4s

Benchmark after:
make-dummies 0 999 -> 0.44s
rmmod dummy -> 0.065s
make-dummies 0 9999 -> 1m36s
rmmod dummy -> 0.4s

Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>

show more ...