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path: root/fs/proc/proc_net.c
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* proc: stop using BKLAlexey Dobriyan2009-01-051-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | There are four BKL users in proc: de_put(), proc_lookup_de(), proc_readdir_de(), proc_root_readdir(), 1) de_put() ----------- de_put() is classic atomic_dec_and_test() refcount wrapper -- no BKL needed. BKL doesn't matter to possible refcount leak as well. 2) proc_lookup_de() ------------------- Walking PDE list is protected by proc_subdir_lock(), proc_get_inode() is potentially blocking, all callers of proc_lookup_de() eventually end up from ->lookup hooks which is protected by directory's ->i_mutex -- BKL doesn't protect anything. 3) proc_readdir_de() -------------------- "." and ".." part doesn't need BKL, walking PDE list is under proc_subdir_lock, calling filldir callback is potentially blocking because it writes to luserspace. All proc_readdir_de() callers eventually come from ->readdir hook which is under directory's ->i_mutex -- BKL doesn't protect anything. 4) proc_root_readdir_de() ------------------------- proc_root_readdir_de is ->readdir hook, see (3). Since readdir hooks doesn't use BKL anymore, switch to generic_file_llseek, since it also takes directory's i_mutex. Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
* netns: make get_proc_net() staticAdrian Bunk2008-07-221-6/+5
| | | | | | | | get_proc_net() can now become static. Signed-off-by: Adrian Bunk <bunk@kernel.org> Acked-by: Pavel Emelyanov <xemul@openvz.org> Signed-off-by: David S. Miller <davem@davemloft.net>
* proc: consolidate per-net single-release callersPavel Emelyanov2008-07-181-0/+8
| | | | | | | They are symmetrical to single_open ones :) Signed-off-by: Pavel Emelyanov <xemul@openvz.org> Signed-off-by: David S. Miller <davem@davemloft.net>
* proc: consolidate per-net single_open callersPavel Emelyanov2008-07-181-0/+24
| | | | | | | There are already 7 of them - time to kill some duplicate code. Signed-off-by: Pavel Emelyanov <xemul@openvz.org> Signed-off-by: David S. Miller <davem@davemloft.net>
* netns: assign PDE->data before gluing entry into /proc treeDenis V. Lunev2008-05-021-11/+0
| | | | | | | | | | In this unfortunate case, proc_mkdir_mode wrapper can't be used anymore and this is no way to reuse proc_create_data due to nlinks assignment. So, copy the code from proc_mkdir and assign PDE->data at the appropriate moment. Signed-off-by: Denis V. Lunev <den@openvz.org> Signed-off-by: David S. Miller <davem@davemloft.net>
* [NETNS]: Remove ifdef CONFIG_NET braces in fs/proc/proc_net.c.Denis V. Lunev2008-04-021-2/+0
| | | | | | | | They are redundant as this file is linked in iff CONFIG_NET is turned on. Signed-off-by: Denis V. Lunev <den@openvz.org> Signed-off-by: David S. Miller <davem@davemloft.net>
* [NETNS]: Compile NET /proc support only if CONFIG_NET is set.Denis V. Lunev2008-03-271-0/+2
| | | | | | | | | | This fix broken compilation for 'allnoconfig'. This was introduced by Introduced by commit 1218854afa6f659be90b748cf1bc7badee954a35 ("[NET] NETNS: Omit seq_net_private->net without CONFIG_NET_NS.") Signed-off-by: Denis V. Lunev <den@openvz.org> Acked-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org> Signed-off-by: David S. Miller <davem@davemloft.net>
* [NET] NETNS: Omit seq_net_private->net without CONFIG_NET_NS.YOSHIFUJI Hideaki2008-03-261-3/+3
| | | | | | | Without CONFIG_NET_NS, no namespace other than &init_net exists, no need to store net in seq_net_private. Signed-off-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
* [NET]: Make /proc/net a symlink on /proc/self/net (v3)Pavel Emelyanov2008-03-071-28/+89
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Current /proc/net is done with so called "shadows", but current implementation is broken and has little chances to get fixed. The problem is that dentries subtree of /proc/net directory has fancy revalidation rules to make processes living in different net namespaces see different entries in /proc/net subtree, but currently, tasks see in the /proc/net subdir the contents of any other namespace, depending on who opened the file first. The proposed fix is to turn /proc/net into a symlink, which points to /proc/self/net, which in turn shows what previously was in /proc/net - the network-related info, from the net namespace the appropriate task lives in. # ls -l /proc/net lrwxrwxrwx 1 root root 8 Mar 5 15:17 /proc/net -> self/net In other words - this behaves like /proc/mounts, but unlike "mounts", "net" is not a file, but a directory. Changes from v2: * Fixed discrepancy of /proc/net nlink count and selinux labeling screwup pointed out by Stephen. To get the correct nlink count the ->getattr callback for /proc/net is overridden to read one from the net->proc_net entry. To make selinux still work the net->proc_net entry is initialized properly, i.e. with the "net" name and the proc_net parent. Selinux fixes are Acked-by: Stephen Smalley <sds@tycho.nsa.gov> Changes from v1: * Fixed a task_struct leak in get_proc_task_net, pointed out by Paul. Signed-off-by: Pavel Emelyanov <xemul@openvz.org> Acked-by: "Eric W. Biederman" <ebiederm@xmission.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* proc: fix ->open'less usage due to ->proc_fops flipAlexey Dobriyan2008-02-081-6/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Typical PDE creation code looks like: pde = create_proc_entry("foo", 0, NULL); if (pde) pde->proc_fops = &foo_proc_fops; Notice that PDE is first created, only then ->proc_fops is set up to final value. This is a problem because right after creation a) PDE is fully visible in /proc , and b) ->proc_fops are proc_file_operations which do not have ->open callback. So, it's possible to ->read without ->open (see one class of oopses below). The fix is new API called proc_create() which makes sure ->proc_fops are set up before gluing PDE to main tree. Typical new code looks like: pde = proc_create("foo", 0, NULL, &foo_proc_fops); if (!pde) return -ENOMEM; Fix most networking users for a start. In the long run, create_proc_entry() for regular files will go. BUG: unable to handle kernel NULL pointer dereference at virtual address 00000024 printing eip: c1188c1b *pdpt = 000000002929e001 *pde = 0000000000000000 Oops: 0002 [#1] PREEMPT SMP DEBUG_PAGEALLOC last sysfs file: /sys/block/sda/sda1/dev Modules linked in: foo af_packet ipv6 cpufreq_ondemand loop serio_raw psmouse k8temp hwmon sr_mod cdrom Pid: 24679, comm: cat Not tainted (2.6.24-rc3-mm1 #2) EIP: 0060:[<c1188c1b>] EFLAGS: 00210002 CPU: 0 EIP is at mutex_lock_nested+0x75/0x25d EAX: 000006fe EBX: fffffffb ECX: 00001000 EDX: e9340570 ESI: 00000020 EDI: 00200246 EBP: e9340570 ESP: e8ea1ef8 DS: 007b ES: 007b FS: 00d8 GS: 0033 SS: 0068 Process cat (pid: 24679, ti=E8EA1000 task=E9340570 task.ti=E8EA1000) Stack: 00000000 c106f7ce e8ee05b4 00000000 00000001 458003d0 f6fb6f20 fffffffb 00000000 c106f7aa 00001000 c106f7ce 08ae9000 f6db53f0 00000020 00200246 00000000 00000002 00000000 00200246 00200246 e8ee05a0 fffffffb e8ee0550 Call Trace: [<c106f7ce>] seq_read+0x24/0x28a [<c106f7aa>] seq_read+0x0/0x28a [<c106f7ce>] seq_read+0x24/0x28a [<c106f7aa>] seq_read+0x0/0x28a [<c10818b8>] proc_reg_read+0x60/0x73 [<c1081858>] proc_reg_read+0x0/0x73 [<c105a34f>] vfs_read+0x6c/0x8b [<c105a6f3>] sys_read+0x3c/0x63 [<c10025f2>] sysenter_past_esp+0x5f/0xa5 [<c10697a7>] destroy_inode+0x24/0x33 ======================= INFO: lockdep is turned off. Code: 75 21 68 e1 1a 19 c1 68 87 00 00 00 68 b8 e8 1f c1 68 25 73 1f c1 e8 84 06 e9 ff e8 52 b8 e7 ff 83 c4 10 9c 5f fa e8 28 89 ea ff <f0> fe 4e 04 79 0a f3 90 80 7e 04 00 7e f8 eb f0 39 76 34 74 33 EIP: [<c1188c1b>] mutex_lock_nested+0x75/0x25d SS:ESP 0068:e8ea1ef8 [akpm@linux-foundation.org: coding-style fixes] Signed-off-by: Alexey Dobriyan <adobriyan@sw.ru> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Oleg Nesterov <oleg@tv-sign.ru> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* [ATM]: Oops reading net/atm/arpDenis V. Lunev2008-01-281-4/+13
| | | | | | | | | | | | | | cat /proc/net/atm/arp causes the NULL pointer dereference in the get_proc_net+0xc/0x3a. This happens as proc_get_net believes that the parent proc dir entry contains struct net. Fix this assumption for "net/atm" case. The problem is introduced by the commit c0097b07abf5f92ab135d024dd41bd2aada1512f from Eric W. Biederman/Daniel Lezcano. Signed-off-by: Denis V. Lunev <den@openvz.org> Signed-off-by: David S. Miller <davem@davemloft.net>
* [NET]: Consolidate net namespace related proc files creation.Denis V. Lunev2008-01-281-0/+38
| | | | | | Signed-off-by: Denis V. Lunev <den@openvz.org> Signed-off-by: Pavel Emelyanov <xemul@openvz.org> Signed-off-by: David S. Miller <davem@davemloft.net>
* [NETNS]: Fix /proc/net breakageEric W. Biederman2007-12-021-81/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Well I clearly goofed when I added the initial network namespace support for /proc/net. Currently things work but there are odd details visible to user space, even when we have a single network namespace. Since we do not cache proc_dir_entry dentries at the moment we can just modify ->lookup to return a different directory inode depending on the network namespace of the process looking at /proc/net, replacing the current technique of using a magic and fragile follow_link method. To accomplish that this patch: - introduces a shadow_proc method to allow different dentries to be returned from proc_lookup. - Removes the old /proc/net follow_link magic - Fixes a weakness in our not caching of proc generic dentries. As shadow_proc uses a task struct to decided which dentry to return we can go back later and fix the proc generic caching without modifying any code that uses the shadow_proc method. Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> Cc: "Rafael J. Wysocki" <rjw@sisk.pl> Cc: Pavel Machek <pavel@ucw.cz> Cc: Pavel Emelyanov <xemul@openvz.org> Cc: "David S. Miller" <davem@davemloft.net> Cc: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
* [NET]: Move unneeded data to initdata section.Denis V. Lunev2007-11-131-1/+1
| | | | | | | | | | This patch reverts Eric's commit 2b008b0a8e96b726c603c5e1a5a7a509b5f61e35 It diets .text & .data section of the kernel if CONFIG_NET_NS is not set. This is safe after list operations cleanup. Signed-of-by: Denis V. Lunev <den@openvz.org> Signed-off-by: David S. Miller <davem@davemloft.net>
* [NET]: Kill proc_net_create()David S. Miller2007-11-071-7/+0
| | | | | | There are no more users. Signed-off-by: David S. Miller <davem@davemloft.net>
* [NET]: Marking struct pernet_operations __net_initdata was inappropriateEric W. Biederman2007-10-261-1/+1
| | | | | | | | | | | | | | | | | | It is not safe to to place struct pernet_operations in a special section. We need struct pernet_operations to last until we call unregister_pernet_subsys. Which doesn't happen until module unload. So marking struct pernet_operations is a disaster for modules in two ways. - We discard it before we call the exit method it points to. - Because I keep struct pernet_operations on a linked list discarding it for compiled in code removes elements in the middle of a linked list and does horrible things for linked insert. So this looks safe assuming __exit_refok is not discarded for modules. Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* [NET] fs/proc/proc_net.c: make a struct staticAdrian Bunk2007-10-261-1/+1
| | | | | | | | Struct proc_net_ns_ops can become static. Signed-off-by: Adrian Bunk <bunk@kernel.org> Acked-by: "Eric W. Biederman" <ebiederm@xmission.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* [NETNS]: Move some code into __init section when CONFIG_NET_NS=nPavel Emelyanov2007-10-101-4/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | With the net namespaces many code leaved the __init section, thus making the kernel occupy more memory than it did before. Since we have a config option that prohibits the namespace creation, the functions that initialize/finalize some netns stuff are simply not needed and can be freed after the boot. Currently, this is almost not noticeable, since few calls are no longer in __init, but when the namespaces will be merged it will be possible to free more code. I propose to use the __net_init, __net_exit and __net_initdata "attributes" for functions/variables that are not used if the CONFIG_NET_NS is not set to save more space in memory. The exiting functions cannot just reside in the __exit section, as noticed by David, since the init section will have references on it and the compilation will fail due to modpost checks. These references can exist, since the init namespace never dies and the exit callbacks are never called. So I introduce the __exit_refok attribute just like it is already done with the __init_refok. Signed-off-by: Pavel Emelyanov <xemul@openvz.org> Signed-off-by: David S. Miller <davem@davemloft.net>
* [NET]: Fix race when opening a proc file while a network namespace is exiting.Eric W. Biederman2007-10-101-0/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | The problem: proc_net files remember which network namespace the are against but do not remember hold a reference count (as that would pin the network namespace). So we currently have a small window where the reference count on a network namespace may be incremented when opening a /proc file when it has already gone to zero. To fix this introduce maybe_get_net and get_proc_net. maybe_get_net increments the network namespace reference count only if it is greater then zero, ensuring we don't increment a reference count after it has gone to zero. get_proc_net handles all of the magic to go from a proc inode to the network namespace instance and call maybe_get_net on it. PROC_NET the old accessor is removed so that we don't get confused and use the wrong helper function. Then I fix up the callers to use get_proc_net and handle the case case where get_proc_net returns NULL. In that case I return -ENXIO because effectively the network namespace has already gone away so the files we are trying to access don't exist anymore. Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> Acked-by: Paul E. McKenney <paulmck@us.ibm.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* [NETNS]: Fix export symbols.Daniel Lezcano2007-10-101-1/+3
| | | | | | | | | | Add the appropriate EXPORT_SYMBOLS for proc_net_create, proc_net_fops_create and proc_net_remove to fix errors when compiling allmodconfig Signed-off-by: Mark Nelson <markn@au1.ibm.com> Acked-by: Benjamin Thery <benjamin.thery@bull.net> Signed-off-by: David S. Miller <davem@davemloft.net>
* [NET]: Fix missed addition of fs/proc/proc_net.cDavid S. Miller2007-10-101-0/+192
My bad. Signed-off-by: David S. Miller <davem@davemloft.net>
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