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path: root/fs/proc/proc_sysctl.c
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* switch all procfs directories ->iterate_shared()Al Viro2016-05-021-1/+1
| | | | Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* proc_sys_fill_cache(): switch to d_alloc_parallel()Al Viro2016-05-021-7/+8
| | | | | | make it usable with directory locked shared Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* fs: Drop unlikely before IS_ERR(_OR_NULL)Viresh Kumar2015-09-291-1/+1
| | | | | | | | | | | IS_ERR(_OR_NULL) already contain an 'unlikely' compiler flag and there is no need to do that again from its callers. Drop it. Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Reviewed-by: Jeff Layton <jlayton@poochiereds.net> Reviewed-by: David Howells <dhowells@redhat.com> Reviewed-by: Steve French <smfrench@gmail.com> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
* sysctl: Allow creating permanently empty directories that serve as mountpoints.Eric W. Biederman2015-07-011-0/+37
| | | | | | | | | | | | | | | Add a magic sysctl table sysctl_mount_point that when used to create a directory forces that directory to be permanently empty. Update the code to use make_empty_dir_inode when accessing permanently empty directories. Update the code to not allow adding to permanently empty directories. Update /proc/sys/fs/binfmt_misc to be a permanently empty directory. Cc: stable@vger.kernel.org Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
* VFS: normal filesystems (and lustre): d_inode() annotationsDavid Howells2015-04-151-6/+6
| | | | | | | that's the bulk of filesystem drivers dealing with inodes of their own Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* sysctl: remove typedef ctl_tableJoe Perches2014-08-081-1/+1
| | | | | | | | Remove the final user, and the typedef itself. Signed-off-by: Joe Perches <joe@perches.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Don't pass inode to ->d_hash() and ->d_compare()Linus Torvalds2013-06-291-3/+4
| | | | | | | | | | | | Instances either don't look at it at all (the majority of cases) or only want it to find the superblock (which can be had as dentry->d_sb). A few cases that want more are actually safe with dentry->d_inode - the only precaution needed is the check that it hadn't been replaced with NULL by rmdir() or by overwriting rename(), which case should be simply treated as cache miss. Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* [readdir] convert procfsAl Viro2013-06-291-44/+27
| | | | Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* fs/proc: clean up printksAndrew Morton2013-02-271-9/+10
| | | | | | | | | | | | - use pr_foo() throughout - remove a couple of duplicated KERN_WARNINGs, via WARN(KERN_WARNING "...") - nuke a few warnings which I've never seen happen, ever. Cc: Joe Perches <joe@perches.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* new helper: file_inode(file)Al Viro2013-02-221-2/+2
| | | | Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* procfs: drop vmtruncateMarco Stornelli2012-12-201-7/+0
| | | | | | | 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 permissionsEric W. Biederman2012-11-181-4/+5
| | | | | | | | | | | | | | | - 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>
* rbtree: fix incorrect rbtree node insertion in fs/proc/proc_sysctl.cMichel Lespinasse2012-10-091-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* rbtree: empty nodes have no colorMichel Lespinasse2012-10-091-3/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* proc_sysctl.c: use BUG_ON instead of BUGPrasad Joshi2012-10-061-2/+1
| | | | | | | | | 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>
* fs/proc: fix potential unregister_sysctl_table hangFrancesco Ruggeri2012-09-171-3/+2
| | | | | | | | | | | | | | | | | | | | | | | 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>
* stop passing nameidata to ->lookup()Al Viro2012-07-141-1/+1
| | | | | | | | | 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>
* stop passing nameidata * to ->d_revalidate()Al Viro2012-07-141-2/+2
| | | | | | 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.Eric W. Biederman2012-05-151-2/+2
| | | | | Acked-by: Serge Hallyn <serge.hallyn@canonical.com> Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
* Merge git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/sysctlLinus Torvalds2012-03-231-76/+1198
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Pull sysctl updates from Eric Biederman: - Rewrite of sysctl for speed and clarity. Insert/remove/Lookup in sysctl are all now O(NlogN) operations, and are no longer bottlenecks in the process of adding and removing network devices. sysctl is now focused on being a filesystem instead of system call and the code can all be found in fs/proc/proc_sysctl.c. Hopefully this means the code is now approachable. Much thanks is owed to Lucian Grinjincu for keeping at this until something was found that was usable. - The recent proc_sys_poll oops found by the fuzzer during hibernation is fixed. * git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/sysctl: (36 commits) sysctl: protect poll() in entries that may go away sysctl: Don't call sysctl_follow_link unless we are a link. sysctl: Comments to make the code clearer. sysctl: Correct error return from get_subdir sysctl: An easier to read version of find_subdir sysctl: fix memset parameters in setup_sysctl_set() sysctl: remove an unused variable sysctl: Add register_sysctl for normal sysctl users sysctl: Index sysctl directories with rbtrees. sysctl: Make the header lists per directory. sysctl: Move sysctl_check_dups into insert_header sysctl: Modify __register_sysctl_paths to take a set instead of a root and an nsproxy sysctl: Replace root_list with links between sysctl_table_sets. sysctl: Add sysctl_print_dir and use it in get_subdir sysctl: Stop requiring explicit management of sysctl directories sysctl: Add a root pointer to ctl_table_set sysctl: Rewrite proc_sys_readdir in terms of first_entry and next_entry sysctl: Rewrite proc_sys_lookup introducing find_entry and lookup_entry. sysctl: Normalize the root_table data structure. sysctl: Factor out insert_header and erase_header ...
| * sysctl: protect poll() in entries that may go awayLucas De Marchi2012-03-221-1/+16
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
| * sysctl: Don't call sysctl_follow_link unless we are a link.Eric W. Biederman2012-02-011-12/+12
| | | | | | | | | | | | | | | | | | 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>
| * sysctl: Comments to make the code clearer.Eric W. Biederman2012-02-011-0/+16
| | | | | | | | | | | | | | 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>
| * sysctl: Correct error return from get_subdirEric W. Biederman2012-02-011-1/+4
| | | | | | | | | | | | | | | | | | 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>
| * sysctl: An easier to read version of find_subdirEric W. Biederman2012-02-011-3/+3
| | | | | | | | | | 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()Dan Carpenter2012-01-301-1/+1
| | | | | | | | | | | | | | 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 variableDan Carpenter2012-01-301-2/+0
| | | | | | | | | | | | | | "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 usersEric W. Biederman2012-01-241-0/+17
| | | | | | | | | | | | | | | | | | | | 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>
| * sysctl: Index sysctl directories with rbtrees.Eric W. Biederman2012-01-241-90/+134
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
| * sysctl: Make the header lists per directory.Eric W. Biederman2012-01-241-17/+11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
| * sysctl: Move sysctl_check_dups into insert_headerEric W. Biederman2012-01-241-9/+11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
| * sysctl: Modify __register_sysctl_paths to take a set instead of a root and ↵Eric W. Biederman2012-01-241-18/+12
| | | | | | | | | | | | | | | | | | | | 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>
| * sysctl: Replace root_list with links between sysctl_table_sets.Eric W. Biederman2012-01-241-102/+295
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
| * sysctl: Add sysctl_print_dir and use it in get_subdirEric W. Biederman2012-01-241-1/+10
| | | | | | | | | | | | | | | | 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>
| * sysctl: Stop requiring explicit management of sysctl directoriesEric W. Biederman2012-01-241-199/+143
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
| * sysctl: Add a root pointer to ctl_table_setEric W. Biederman2012-01-241-0/+3
| | | | | | | | | | | | | | Add a ctl_table_root pointer to ctl_table set so it is easy to go from a ctl_table_set to a ctl_table_root. Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
| * sysctl: Rewrite proc_sys_readdir in terms of first_entry and next_entryEric W. Biederman2012-01-241-36/+62
| | | | | | | | | | | | | | | | | | | | | | | | | | Replace sysctl_head_next with first_entry and next_entry. These new iterators operate at the level of sysctl table entries and filter out any sysctl tables that should not be shown. Utilizing two specialized functions instead of a single function removes conditionals for handling awkward special cases that only come up at the beginning of iteration, making the iterators easier to read and understand. Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
| * sysctl: Rewrite proc_sys_lookup introducing find_entry and lookup_entry.Eric W. Biederman2012-01-241-26/+76
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Replace the helpers that proc_sys_lookup uses with helpers that work in terms of an entire sysctl directory. This is worse for sysctl_lock hold times but it is much better for code clarity and the code cleanups to come. find_in_table is no longer needed so it is removed. find_entry a general helper to find entries in a directory is added. lookup_entry is a simple wrapper around find_entry that takes the sysctl_lock increases the use count if an entry is found and drops the sysctl_lock. Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
| * sysctl: Normalize the root_table data structure.Eric W. Biederman2012-01-241-4/+11
| | | | | | | | | | | | | | Every other directory has a .child member and we look at the .child for our entries. Do the same for the root_table. Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
| * sysctl: Factor out insert_header and erase_headerEric W. Biederman2012-01-241-3/+13
| | | | | | | | Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
| * sysctl: Factor out init_header from __register_sysctl_pathsEric W. Biederman2012-01-241-8/+17
| | | | | | | | | | | | Factor out a routing to initialize the sysctl_table_header. Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
| * sysctl: Initial support for auto-unregistering sysctl tables.Eric W. Biederman2012-01-241-9/+19
| | | | | | | | | | | | | | | | | | | | Add nreg to ctl_table_header. When nreg drops to 0 the ctl_table_header will be unregistered. Factor out drop_sysctl_table from unregister_sysctl_table, and add the logic for decrementing nreg. Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
| * sysctl: A more obvious version of grab_header.Eric W. Biederman2012-01-241-4/+4
| | | | | | | | | | | | | | | | Instead of relying on sysct_head_next(NULL) to magically return the right header for the root directory instead explicitly transform NULL into the root directories header. Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
| * sysctl: Remove the now unused ctl_table parent field.Eric W. Biederman2012-01-241-11/+1
| | | | | | | | | | | | | | | | | | While useful at one time for selinux and the sysctl sanity checks those users no longer use the parent field and we can safely remove it. Inspired-by: Lucian Adrian Grijincu <lucian.grijincu@gmil.com> Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
| * sysctl: Improve the sysctl sanity checksEric W. Biederman2012-01-241-136/+86
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | - Stop validating subdirectories now that we only register leaf tables - Cleanup and improve the duplicate filename check. * Run the duplicate filename check under the sysctl_lock to guarantee we never add duplicate names. * Reduce the duplicate filename check to nearly O(M*N) where M is the number of entries in tthe table we are registering and N is the number of entries in the directory before we got there. - Move the duplicate filename check into it's own function and call it directtly from __register_sysctl_table - Kill the config option as the sanity checks are now cheap enough the config option is unnecessary. The original reason for the config option was because we had a huge table used to verify the proc filename to binary sysctl mapping. That table has now evolved into the binary_sysctl translation layer and is no longer part of the sysctl_check code. - Tighten up the permission checks. Guarnateeing that files only have read or write permissions. - Removed redudant check for parents having a procname as now everything has a procname. - Generalize the backtrace logic so that we print a backtrace from any failure of __register_sysctl_table that was not caused by a memmory allocation failure. The backtrace allows us to track down who erroneously registered a sysctl table. Bechmark before (CONFIG_SYSCTL_CHECK=y): make-dummies 0 999 -> 12s rmmod dummy -> 0.08s Bechmark before (CONFIG_SYSCTL_CHECK=n): make-dummies 0 999 -> 0.7s rmmod dummy -> 0.06s make-dummies 0 99999 -> 1m13s rmmod dummy -> 0.38s Benchmark after: make-dummies 0 999 -> 0.65s rmmod dummy -> 0.055s make-dummies 0 9999 -> 1m10s rmmod dummy -> 0.39s The sysctl sanity checks now impose no measurable cost. Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
| * sysctl: register only tables of sysctl filesEric W. Biederman2012-01-241-18/+147
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Split the registration of a complex ctl_table array which may have arbitrary numbers of directories (->child != NULL) and tables of files into a series of simpler registrations that only register tables of files. Graphically: register('dir', { + file-a + file-b + subdir1 + file-c + subdir2 + file-d + file-e }) is transformed into: wrapper->subheaders[0] = register('dir', {file1-a, file1-b}) wrapper->subheaders[1] = register('dir/subdir1', {file-c}) wrapper->subheaders[2] = register('dir/subdir2', {file-d, file-e}) return wrapper This guarantees that __register_sysctl_table will only see a simple ctl_table array with all entries having (->child == NULL). Care was taken to pass the original simple ctl_table arrays to __register_sysctl_table whenever possible. This change is derived from a similar patch written by Lucrian Grijincu. Inspired-by: Lucian Adrian Grijincu <lucian.grijincu@gmail.com> Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
| * sysctl: Add ctl_table chains into cstring pathsEric W. Biederman2012-01-241-0/+9
| | | | | | | | | | | | | | | | | | | | | | | | For any component of table passed to __register_sysctl_paths that actually serves as a path, add that to the cstring path that is passed to __register_sysctl_table. The result is that for most calls to __register_sysctl_paths we only pass a table to __register_sysctl_table that contains no child directories. Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
| * sysctl: Add support for register sysctl tables with a normal cstring path.Eric W. Biederman2012-01-241-10/+84
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Make __register_sysctl_table the core sysctl registration operation and make it take a char * string as path. Now that binary paths have been banished into the real of backwards compatibility in kernel/binary_sysctl.c where they can be safely ignored there is no longer a need to use struct ctl_path to represent path names when registering ctl_tables. Start the transition to using normal char * strings to represent pathnames when registering sysctl tables. Normal strings are easier to deal with both in the internal sysctl implementation and for programmers registering sysctl tables. __register_sysctl_paths is turned into a backwards compatibility wrapper that converts a ctl_path array into a normal char * string. Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
| * sysctl: Create local copies of directory names used in pathsEric W. Biederman2012-01-241-3/+8
| | | | | | | | | | | | | | | | | | | | | | | | | | | | Creating local copies of directory names is a good idea for two reasons. - The dynamic names used by callers must be copied into new strings by the callers today to ensure the strings do not change between register and unregister of the sysctl table. - Sysctl directories have a potentially different lifetime than the time between register and unregister of any particular sysctl table. Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
| * sysctl: Remove the unnecessary sysctl_set parent concept.Eric W. Biederman2012-01-241-3/+8
| | | | | | | | | | | | | | | | | | | | | | | | In sysctl_net register the two networking roots in the proper order. In register_sysctl walk the sysctl sets in the reverse order of the sysctl roots. Remove parent from ctl_table_set and setup_sysctl_set as it is no longer needed. Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
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