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* proc: stop using BKLAlexey Dobriyan2009-01-051-6/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* proc: use WARN() rather than printk+backtraceArjan van de Ven2008-10-231-2/+1
| | | | | | | | | | Use WARN() rather than a printk() + backtrace(); this gives a more standard format message as well as complete information (including line numbers etc) that will be collected by kerneloops.org Signed-off-by: Arjan van de Ven <arjan@linux.intel.com> Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
* proc: more debugging for "already registered" caseAlexey Dobriyan2008-09-131-2/+2
| | | | | | | | | | | | | Print parent directory name as well. The aim is to catch non-creation of parent directory when proc_mkdir will return NULL and all subsequent registrations go directly in /proc instead of intended directory. Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> [ Fixed insane printk string while at it. - Linus ] Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* [PATCH] proc: inode number fixletAlexey Dobriyan2008-08-251-0/+1
| | | | | | | | | | Ouch, if number taken from IDA is too big, the intent was to signal an error, not check for overflow and still do overflowing addition. One still needs 2^28 proc entries to notice this. Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* [PATCH 2/2] proc: switch inode number allocation to IDAAlexey Dobriyan2008-08-011-5/+5
| | | | | | | | | | | proc doesn't use "associate pointer with id" feature of IDR, so switch to IDA. NOTE, NOTE, NOTE: Do not apply if release_inode_number() still mantions MAX_ID_MASK! Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* [PATCH 1/2] proc: fix inode number bogorithmeticAlexey Dobriyan2008-08-011-12/+9
| | | | | | | | | | | | | | | | | | | Id which proc gets from IDR for inode number and id which proc removes from IDR do not match. E.g. 0x11a transforms into 0x8000011a. Which stayed unnoticed for a long time because, surprise, idr_remove() masks out that high bit before doing anything. All of this due to "| ~MAX_ID_MASK" in release_inode_number(). I still don't understand how it's supposed to work, because "| ~MASK" is not an inversion for "& MAX" operation. So, use just one nice, working addition. Make start offset unsigned int, while I'm at it. It's longness is not used anywhere. Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* Use WARN() in fs/proc/Arjan van de Ven2008-07-261-4/+1
| | | | | | | | | | | Use WARN() instead of a printk+WARN_ON() pair; this way the message becomes part of the warning section for better reporting/collection. This way, the entire if() {} section can collapse into the WARN() as well. Signed-off-by: Arjan van de Ven <arjan@linux.intel.com> Acked-by: Alexey Dobriyan <adobriyan@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* proc: always do ->releaseAlexey Dobriyan2008-07-251-0/+14
| | | | | | | | | | | | | | | | | | | | | | Current two-stage scheme of removing PDE emphasizes one bug in proc: open rmmod remove_proc_entry close ->release won't be called because ->proc_fops were cleared. In simple cases it's small memory leak. For every ->open, ->release has to be done. List of openers is introduced which is traversed at remove_proc_entry() if neeeded. Discussions with Al long ago (sigh). Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* netns: assign PDE->data before gluing entry into /proc treeDenis V. Lunev2008-05-021-0/+17
| | | | | | | | | | 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>
* proc: introduce proc_create_data to setup de->dataDenis V. Lunev2008-04-291-3/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This set of patches fixes an proc ->open'less usage due to ->proc_fops flip in the most part of the kernel code. The original OOPS is described in the commit 2d3a4e3666325a9709cc8ea2e88151394e8f20fc: 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. In addition to this, proc_create_data is introduced to fix reading from proc without PDE->data. The race is basically the same as above. create_proc_entries is replaced in the entire kernel code as new method is also simply better. This patch: The problem is the same as for de->proc_fops. Right now PDE becomes visible without data set. So, the entry could be looked up without data. This, in most cases, will simply OOPS. proc_create_data call is created to address this issue. proc_create now becomes a wrapper around it. Signed-off-by: Denis V. Lunev <den@openvz.org> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: "J. Bruce Fields" <bfields@fieldses.org> Cc: Alessandro Zummo <a.zummo@towertech.it> Cc: Alexey Dobriyan <adobriyan@gmail.com> Cc: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Bjorn Helgaas <bjorn.helgaas@hp.com> Cc: Chris Mason <chris.mason@oracle.com> Acked-by: David Howells <dhowells@redhat.com> Cc: Dmitry Torokhov <dtor@mail.ru> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Grant Grundler <grundler@parisc-linux.org> Cc: Greg Kroah-Hartman <gregkh@suse.de> Cc: Haavard Skinnemoen <hskinnemoen@atmel.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: James Bottomley <James.Bottomley@HansenPartnership.com> Cc: Jaroslav Kysela <perex@suse.cz> Cc: Jeff Garzik <jgarzik@pobox.com> Cc: Jeff Mahoney <jeffm@suse.com> Cc: Jesper Nilsson <jesper.nilsson@axis.com> Cc: Karsten Keil <kkeil@suse.de> Cc: Kyle McMartin <kyle@parisc-linux.org> Cc: Len Brown <lenb@kernel.org> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca> Cc: Matthew Wilcox <matthew@wil.cx> Cc: Mauro Carvalho Chehab <mchehab@infradead.org> Cc: Mikael Starvik <starvik@axis.com> Cc: Nadia Derbey <Nadia.Derbey@bull.net> Cc: Neil Brown <neilb@suse.de> Cc: Paul Mackerras <paulus@samba.org> Cc: Peter Osterlund <petero2@telia.com> Cc: Pierre Peiffer <peifferp@gmail.com> Cc: Russell King <rmk@arm.linux.org.uk> Cc: Takashi Iwai <tiwai@suse.de> Cc: Tony Luck <tony.luck@intel.com> Cc: Trond Myklebust <trond.myklebust@fys.uio.no> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* proc: remove ->get_info infrastructureAlexey Dobriyan2008-04-291-6/+1
| | | | | | | | | | | | | | | | Now that last dozen or so users of ->get_info were removed, ditch it too. Everyone sane shouldd have switched to seq_file interface long ago. P.S.: Co-existing 3 interfaces (->get_info/->read_proc/->proc_fops) for proc is long-standing crap, BTW, thus a) put ->read_proc/->write_proc/read_proc_entry() users on death row, b) new such users should be rejected, c) everyone is encouraged to convert his favourite ->read_proc user or I'll do it, lazy bastards. Signed-off-by: Alexey Dobriyan <adobriyan@sw.ru> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* proc: drop several "PDE valid/invalid" checksAlexey Dobriyan2008-04-291-19/+14
| | | | | | | | | | | proc-misc code is noticeably full of "if (de)" checks when PDE passed is always valid. Remove them. Addition of such check in proc_lookup_de() is for failed lookup case. Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* proc: less special case in xlate codeAlexey Dobriyan2008-04-291-3/+6
| | | | | | | | | | | | | | | | | | | | | | | | If valid "parent" is passed to proc_create/remove_proc_entry(), then name of PDE should consist of only one path component, otherwise creation or or removal will fail. However, if NULL is passed as parent then create/remove accept full path as a argument. This is arbitrary restriction -- all infrastructure is in place. So, patch allows the following to succeed: create_proc_entry("foo/bar", 0, pde_baz); remove_proc_entry("baz/foo/bar", &proc_root); Also makes the following to behave identically: create_proc_entry("foo/bar", 0, NULL); create_proc_entry("foo/bar", 0, &proc_root); Discrepancy noticed by Den Lunev (IIRC). Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* proc: simplify locking in remove_proc_entry()Alexey Dobriyan2008-04-291-42/+40
| | | | | | | | | | proc_subdir_lock protects only modifying and walking through PDE lists, so after we've found PDE to remove and actually removed it from lists, there is no need to hold proc_subdir_lock for the rest of operation. Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* proc: print more information when removing non-empty directoriesAlexey Dobriyan2008-04-291-1/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This usually saves one recompile to insert similar printk like below. :) Sample nastygram: remove_proc_entry: removing non-empty directory '/proc/foo', leaking at least 'bar' ------------[ cut here ]------------ WARNING: at fs/proc/generic.c:776 remove_proc_entry+0x18a/0x200() Modules linked in: foo(-) container fan battery dock sbs ac sbshc backlight ipv6 loop af_packet amd_rng sr_mod i2c_amd8111 i2c_amd756 cdrom i2c_core button thermal processor Pid: 3034, comm: rmmod Tainted: G M 2.6.25-rc1 #5 Call Trace: [<ffffffff80231974>] warn_on_slowpath+0x64/0x90 [<ffffffff80232a6e>] printk+0x4e/0x60 [<ffffffff802d6c8a>] remove_proc_entry+0x18a/0x200 [<ffffffff8045cd88>] mutex_lock_nested+0x1c8/0x2d0 [<ffffffff8025f0f0>] __try_stop_module+0x0/0x40 [<ffffffff8025effd>] sys_delete_module+0x14d/0x200 [<ffffffff8045df3d>] lockdep_sys_exit_thunk+0x35/0x67 [<ffffffff8031c307>] __up_read+0x27/0xa0 [<ffffffff8045decc>] trace_hardirqs_on_thunk+0x35/0x3a [<ffffffff8020b6ab>] system_call_after_swapgs+0x7b/0x80 ---[ end trace 10ef850597e89c54 ]--- Signed-off-by: Alexey Dobriyan <adobriyan@sw.ru> Cc: Arjan van de Ven <arjan@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* [NET]: Make /proc/net a symlink on /proc/self/net (v3)Pavel Emelyanov2008-03-071-9/+17
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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 Dobriyan2008-02-081-4/+36
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* proc: detect duplicate names on registrationZhang Rui2008-02-081-0/+10
| | | | | | | | | | | | | | | Print a warning if PDE is registered with a name which already exists in target directory. Bug report and a simple fix can be found here: http://bugzilla.kernel.org/show_bug.cgi?id=8798 [\n fixlet and no undescriptive variable usage --adobriyan] [akpm@linux-foundation.org: make printk comprehensible] Signed-off-by: Zhang Rui <rui.zhang@intel.com> Signed-off-by: Alexey Dobriyan <adobriyan@sw.ru> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* proc: remove useless check on symlink removalAlexey Dobriyan2008-02-081-1/+1
| | | | | | | | | proc symlinks always have valid ->data containing destination of symlink. No need to check it on removal -- proc_symlink() already done it. Signed-off-by: Alexey Dobriyan <adobriyan@sw.ru> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* proc: simplify function prototypesAlexey Dobriyan2008-02-081-12/+6
| | | | | | | | Move code around so as to reduce the number of forward-declarations. Signed-off-by: Alexey Dobriyan <adobriyan@sw.ru> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* proc: less LOCK operations during lookupAlexey Dobriyan2008-02-081-2/+2
| | | | | | | | | | | | | | | | | | | | | | | Pseudo-code for lookup effectively is: LOCK kernel LOCK proc_subdir_lock find PDE UNLOCK proc_subdir_lock get inode LOCK proc_subdir_lock goto unlock UNLOCK proc_subdir_lock UNLOCK kernel We can get rid of LOCK/UNLOCK pair after getting inode simply by jumping to unlock_kernel() directly. Signed-off-by: Alexey Dobriyan <adobriyan@sw.ru> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* proc: remove/Fix proc generic d_revalidateEric W. Biederman2007-12-101-7/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Ultimately to implement /proc perfectly we need an implementation of d_revalidate because files and directories can be removed behind the back of the VFS, and d_revalidate is the only way we can let the VFS know that this has happened. Unfortunately the linux VFS can not cope with anything in the path to a mount point going away. So a proper d_revalidate method that calls d_drop also needs to call have_submounts which is moderately expensive, so you really don't want a d_revalidate method that unconditionally calls it, but instead only calls it when the backing object has really gone away. proc generic entries only disappear on module_unload (when not counting the fledgling network namespace) so it is quite rare that we actually encounter that case and has not actually caused us real world trouble yet. So until we get a proper test for keeping dentries in the dcache fix the current d_revalidate method by completely removing it. This returns us to the current status quo. So with CONFIG_NETNS=n things should look as they have always looked. For CONFIG_NETNS=y things work most of the time but there are a few rare corner cases that don't behave properly. As the network namespace is barely present in 2.6.24 this should not be a problem. Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> Cc: "Rafael J. Wysocki" <rjw@sisk.pl> Cc: Pavel Emelyanov <xemul@openvz.org> Cc: "David S. Miller" <davem@davemloft.net> Cc: Herbert Xu <herbert@gondor.apana.org.au> Cc: Alexey Dobriyan <adobriyan@gmail.com> Cc: Trond Myklebust <trond.myklebust@fys.uio.no> 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>
* proc: fix proc_dir_entry refcountingAlexey Dobriyan2007-12-051-7/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Creating PDEs with refcount 0 and "deleted" flag has problems (see below). Switch to usual scheme: * PDE is created with refcount 1 * every de_get does +1 * every de_put() and remove_proc_entry() do -1 * once refcount reaches 0, PDE is freed. This elegantly fixes at least two following races (both observed) without introducing new locks, without abusing old locks, without spreading lock_kernel(): 1) PDE leak remove_proc_entry de_put ----------------- ------ [refcnt = 1] if (atomic_read(&de->count) == 0) if (atomic_dec_and_test(&de->count)) if (de->deleted) /* also not taken! */ free_proc_entry(de); else de->deleted = 1; [refcount=0, deleted=1] 2) use after free remove_proc_entry de_put ----------------- ------ [refcnt = 1] if (atomic_dec_and_test(&de->count)) if (atomic_read(&de->count) == 0) free_proc_entry(de); /* boom! */ if (de->deleted) free_proc_entry(de); BUG: unable to handle kernel paging request at virtual address 6b6b6b6b printing eip: c10acdda *pdpt = 00000000338f8001 *pde = 0000000000000000 Oops: 0000 [#1] PREEMPT SMP Modules linked in: af_packet ipv6 cpufreq_ondemand loop serio_raw psmouse k8temp hwmon sr_mod cdrom Pid: 23161, comm: cat Not tainted (2.6.24-rc2-8c0863403f109a43d7000b4646da4818220d501f #4) EIP: 0060:[<c10acdda>] EFLAGS: 00210097 CPU: 1 EIP is at strnlen+0x6/0x18 EAX: 6b6b6b6b EBX: 6b6b6b6b ECX: 6b6b6b6b EDX: fffffffe ESI: c128fa3b EDI: f380bf34 EBP: ffffffff ESP: f380be44 DS: 007b ES: 007b FS: 00d8 GS: 0033 SS: 0068 Process cat (pid: 23161, ti=f380b000 task=f38f2570 task.ti=f380b000) Stack: c10ac4f0 00000278 c12ce000 f43cd2a8 00000163 00000000 7da86067 00000400 c128fa20 00896b18 f38325a8 c128fe20 ffffffff 00000000 c11f291e 00000400 f75be300 c128fa20 f769c9a0 c10ac779 f380bf34 f7bfee70 c1018e6b f380bf34 Call Trace: [<c10ac4f0>] vsnprintf+0x2ad/0x49b [<c10ac779>] vscnprintf+0x14/0x1f [<c1018e6b>] vprintk+0xc5/0x2f9 [<c10379f1>] handle_fasteoi_irq+0x0/0xab [<c1004f44>] do_IRQ+0x9f/0xb7 [<c117db3b>] preempt_schedule_irq+0x3f/0x5b [<c100264e>] need_resched+0x1f/0x21 [<c10190ba>] printk+0x1b/0x1f [<c107c8ad>] de_put+0x3d/0x50 [<c107c8f8>] proc_delete_inode+0x38/0x41 [<c107c8c0>] proc_delete_inode+0x0/0x41 [<c1066298>] generic_delete_inode+0x5e/0xc6 [<c1065aa9>] iput+0x60/0x62 [<c1063c8e>] d_kill+0x2d/0x46 [<c1063fa9>] dput+0xdc/0xe4 [<c10571a1>] __fput+0xb0/0xcd [<c1054e49>] filp_close+0x48/0x4f [<c1055ee9>] sys_close+0x67/0xa5 [<c10026b6>] sysenter_past_esp+0x5f/0x85 ======================= Code: c9 74 0c f2 ae 74 05 bf 01 00 00 00 4f 89 fa 5f 89 d0 c3 85 c9 57 89 c7 89 d0 74 05 f2 ae 75 01 4f 89 f8 5f c3 89 c1 89 c8 eb 06 <80> 38 00 74 07 40 4a 83 fa ff 75 f4 29 c8 c3 90 90 90 57 83 c9 EIP: [<c10acdda>] strnlen+0x6/0x18 SS:ESP 0068:f380be44 Also, remove broken usage of ->deleted from reiserfs: if sget() succeeds, module is already pinned and remove_proc_entry() can't happen => nobody can mark PDE deleted. Dummy proc root in netns code is not marked with refcount 1. AFAICS, we never get it, it's just for proper /proc/net removal. I double checked CLONE_NETNS continues to work. Patch survives many hours of modprobe/rmmod/cat loops without new bugs which can be attributed to refcounting. Signed-off-by: Alexey Dobriyan <adobriyan@sw.ru> 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>
* Merge git://git.kernel.org/pub/scm/linux/kernel/git/herbert/net-2.6Linus Torvalds2007-12-031-1/+11
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | * git://git.kernel.org/pub/scm/linux/kernel/git/herbert/net-2.6: (27 commits) [INET]: Fix inet_diag dead-lock regression [NETNS]: Fix /proc/net breakage [TEXTSEARCH]: Do not allow zero length patterns in the textsearch infrastructure [NETFILTER]: fix forgotten module release in xt_CONNMARK and xt_CONNSECMARK [NETFILTER]: xt_TCPMSS: remove network triggerable WARN_ON [DECNET]: dn_nl_deladdr() almost always returns no error [IPV6]: Restore IPv6 when MTU is big enough [RXRPC]: Add missing select on CRYPTO mac80211: rate limit wep decrypt failed messages rfkill: fix double-mutex-locking mac80211: drop unencrypted frames if encryption is expected mac80211: Fix behavior of ieee80211_open and ieee80211_close ieee80211: fix unaligned access in ieee80211_copy_snap mac80211: free ifsta->extra_ie and clear IEEE80211_STA_PRIVACY_INVOKED SCTP: Fix build issues with SCTP AUTH. SCTP: Fix chunk acceptance when no authenticated chunks were listed. SCTP: Fix the supported extensions paramter SCTP: Fix SCTP-AUTH to correctly add HMACS paramter. SCTP: Fix the number of HB transmissions. [TCP] illinois: Incorrect beta usage ...
| * [NETNS]: Fix /proc/net breakageEric W. Biederman2007-12-021-1/+11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* | proc: fix NULL ->i_fop oopsAlexey Dobriyan2007-11-291-37/+0
|/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | proc_kill_inodes() can clear ->i_fop in the middle of vfs_readdir resulting in NULL dereference during "file->f_op->readdir(file, buf, filler)". The solution is to remove proc_kill_inodes() completely: a) we don't have tricky modules implementing their tricky readdir hooks which could keeping this revoke from hell. b) In a situation when module is gone but PDE still alive, standard readdir will return only "." and "..", because pde->next was cleared by remove_proc_entry(). c) the race proc_kill_inode() destined to prevent is not completely fixed, just race window made smaller, because vfs_readdir() is run without sb_lock held and without file_list_lock held. Effectively, ->i_fop is cleared at random moment, which can't fix properly anything. BUG: unable to handle kernel NULL pointer dereference at virtual address 00000018 printing eip: c1061205 *pdpt = 0000000005b22001 *pde = 0000000000000000 Oops: 0000 [#1] PREEMPT SMP Modules linked in: foo af_packet ipv6 cpufreq_ondemand loop serio_raw sr_mod k8temp cdrom hwmon amd_rng Pid: 2033, comm: find Not tainted (2.6.24-rc1-b1d08ac064268d0ae2281e98bf5e82627e0f0c56 #2) EIP: 0060:[<c1061205>] EFLAGS: 00010246 CPU: 0 EIP is at vfs_readdir+0x47/0x74 EAX: c6b6a780 EBX: 00000000 ECX: c1061040 EDX: c5decf94 ESI: c6b6a780 EDI: fffffffe EBP: c9797c54 ESP: c5decf78 DS: 007b ES: 007b FS: 00d8 GS: 0033 SS: 0068 Process find (pid: 2033, ti=c5dec000 task=c64bba90 task.ti=c5dec000) Stack: c5decf94 c1061040 fffffff7 0805ffbc 00000000 c6b6a780 c1061295 0805ffbc 00000000 00000400 00000000 00000004 0805ffbc 4588eff4 c5dec000 c10026ba 00000004 0805ffbc 00000400 0805ffbc 4588eff4 bfdc6c70 000000dc 0000007b Call Trace: [<c1061040>] filldir64+0x0/0xc5 [<c1061295>] sys_getdents64+0x63/0xa5 [<c10026ba>] sysenter_past_esp+0x5f/0x85 ======================= Code: 49 83 78 18 00 74 43 8d 6b 74 bf fe ff ff ff 89 e8 e8 b8 c0 12 00 f6 83 2c 01 00 00 10 75 22 8b 5e 10 8b 4c 24 04 89 f0 8b 14 24 <ff> 53 18 f6 46 1a 04 89 c7 75 0b 8b 56 0c 8b 46 08 e8 c8 66 00 EIP: [<c1061205>] vfs_readdir+0x47/0x74 SS:ESP 0068:c5decf78 hch: "Nice, getting rid of this is a very good step formwards. Unfortunately we have another copy of this junk in security/selinux/selinuxfs.c:sel_remove_entries() which would need the same treatment." Signed-off-by: Alexey Dobriyan <adobriyan@sw.ru> Acked-by: Christoph Hellwig <hch@infradead.org> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Stephen Smalley <sds@tycho.nsa.gov> Cc: James Morris <jmorris@namei.org> 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>
* proc: fix proc_kill_inodes to kill dentries on all proc superblocksEric W. Biederman2007-11-141-17/+22
| | | | | | | | | | | | | | It appears we overlooked support for removing generic proc files when we added support for multiple proc super blocks. Handle that now. [akpm@linux-foundation.org: coding-style cleanups] Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> Acked-by: Pavel Emelyanov <xemul@openvz.org> Cc: Alexey Dobriyan <adobriyan@sw.ru> Acked-by: Sukadev Bhattiprolu <sukadev@us.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Group short-lived and reclaimable kernel allocationsMel Gorman2007-10-161-1/+1
| | | | | | | | | | | | | | | | | | This patch marks a number of allocations that are either short-lived such as network buffers or are reclaimable such as inode allocations. When something like updatedb is called, long-lived and unmovable kernel allocations tend to be spread throughout the address space which increases fragmentation. This patch groups these allocations together as much as possible by adding a new MIGRATE_TYPE. The MIGRATE_RECLAIMABLE type is for allocations that can be reclaimed on demand, but not moved. i.e. they can be migrated by deleting them and re-reading the information from elsewhere. Signed-off-by: Mel Gorman <mel@csn.ul.ie> Cc: Andy Whitcroft <apw@shadowen.org> Cc: Christoph Lameter <clameter@sgi.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* procfs directory entry cleanupChangli Gao2007-07-161-13/+7
| | | | | | | | | | | Function proc_register() will assign proc_dir_operations and proc_dir_inode_operations to ent's members proc_fops and proc_iops correctly if ent is a directory. So the early assignment isn't necessary. Cc: Alexey Dobriyan <adobriyan@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Fix rmmod/read/write races in /proc entriesAlexey Dobriyan2007-07-161-1/+31
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Fix following races: =========================================== 1. Write via ->write_proc sleeps in copy_from_user(). Module disappears meanwhile. Or, more generically, system call done on /proc file, method supplied by module is called, module dissapeares meanwhile. pde = create_proc_entry() if (!pde) return -ENOMEM; pde->write_proc = ... open write copy_from_user pde = create_proc_entry(); if (!pde) { remove_proc_entry(); return -ENOMEM; /* module unloaded */ } *boom* ========================================== 2. bogo-revoke aka proc_kill_inodes() remove_proc_entry vfs_read proc_kill_inodes [check ->f_op validness] [check ->f_op->read validness] [verify_area, security permissions checks] ->f_op = NULL; if (file->f_op->read) /* ->f_op dereference, boom */ NOTE, NOTE, NOTE: file_operations are proxied for regular files only. Let's see how this scheme behaves, then extend if needed for directories. Directories creators in /proc only set ->owner for them, so proxying for directories may be unneeded. NOTE, NOTE, NOTE: methods being proxied are ->llseek, ->read, ->write, ->poll, ->unlocked_ioctl, ->ioctl, ->compat_ioctl, ->open, ->release. If your in-tree module uses something else, yell on me. Full audit pending. [akpm@linux-foundation.org: build fix] Signed-off-by: Alexey Dobriyan <adobriyan@sw.ru> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Fix race between proc_readdir and remove_proc_entryDarrick J. Wong2007-05-081-2/+9
| | | | | | | | | | | | | | | | | | | | | | | | Fix the following race: proc_readdir remove_proc_entry ============ ================= spin_lock(&proc_subdir_lock); [choose PDE to start filldir from] spin_unlock(&proc_subdir_lock); spin_lock(&proc_subdir_lock); [find PDE] [free PDE, refcount is 0] spin_unlock(&proc_subdir_lock); /* boom */ if (filldir(dirent, de->name, ... [de_put on error path --adobriyan] Signed-off-by: Darrick J. Wong <djwong@us.ibm.com> Signed-off-by: Alexey Dobriyan <adobriyan@sw.ru> 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>
* Fix race between proc_get_inode() and remove_proc_entry()Alexey Dobriyan2007-05-081-0/+2
| | | | | | | | | | | | | | | | | | | | | | proc_lookup remove_proc_entry =========== ================= lock_kernel(); spin_lock(&proc_subdir_lock); [find PDE with refcount 0] spin_unlock(&proc_subdir_lock); spin_lock(&proc_subdir_lock); [find PDE with refcount 0] [check refcount and free PDE] spin_unlock(&proc_subdir_lock); proc_get_inode: de_get(de); /* boom */ Signed-off-by: Alexey Dobriyan <adobriyan@openvz.org> 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>
* [PATCH] sysctl: reimplement the sysctl proc supportEric W. Biederman2007-02-141-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* [PATCH] mark struct inode_operations const 3Arjan van de Ven2007-02-121-3/+3
| | | | | | | | | | | Many struct inode_operations in the kernel can be "const". Marking them const moves these to the .rodata section, which avoids false sharing with potential dirty data. In addition it'll catch accidental writes at compile time to these shared resources. Signed-off-by: Arjan van de Ven <arjan@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* [PATCH] mark struct file_operations const 6Arjan van de Ven2007-02-121-2/+2
| | | | | | | | | | | Many struct file_operations in the kernel can be "const". Marking them const moves these to the .rodata section, which avoids false sharing with potential dirty data. In addition it'll catch accidental writes at compile time to these shared resources. Signed-off-by: Arjan van de Ven <arjan@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* [PATCH] proc: change uses of f_{dentry, vfsmnt} to use f_pathJosef "Jeff" Sipek2006-12-081-5/+5
| | | | | | | | | Change all the uses of f_{dentry,vfsmnt} to f_path.{dentry,mnt} in the proc filesystem code. Signed-off-by: Josef "Jeff" Sipek <jsipek@cs.sunysb.edu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] mark f_ops const in the inodeArjan van de Ven2006-03-281-1/+1
| | | | | | | | | | | Mark the f_ops members of inodes as const, as well as fix the ripple-through this causes by places that copy this f_ops and then "do stuff" with it. Signed-off-by: Arjan van de Ven <arjan@infradead.org> Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] protect remove_proc_entrySteven Rostedt2006-03-261-3/+29
| | | | | | | | | | | | | | | | | | | | | | | | | | It has been discovered that the remove_proc_entry has a race in the removing of entries in the proc file system that are siblings. There's no protection around the traversing and removing of elements that belong in the same subdirectory. This subdirectory list is protected in other areas by the BKL. So the BKL was at first used to protect this area too, but unfortunately, remove_proc_entry may be called with spinlocks held. The BKL may schedule, so this was not a solution. The final solution was to add a new global spin lock to protect this list, called proc_subdir_lock. This lock now protects the list in remove_proc_entry, and I also went around looking for other areas that this list is modified and added this protection there too. Care must be taken since these locations call several functions that may also schedule. Since I don't see any location that these functions that modify the subdirectory list are called by interrupts, the irqsave/restore versions of the spin lock was _not_ used. Signed-off-by: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] fs/proc/: function prototypes belong in header filesAdrian Bunk2006-01-081-0/+2
| | | | | | | | Function prototypes belong into header files. Signed-off-by: Adrian Bunk <bunk@stusta.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* Insanity avoidance in /procLinus Torvalds2005-12-301-24/+23
| | | | | | | | | | | | The old /proc interfaces were never updated to use loff_t, and are just generally broken. Now, we should be using the seq_file interface for all of the proc files, but converting the legacy functions is more work than most people care for and has little upside.. But at least we can make the non-LFS rules explicit, rather than just insanely wrapping the offset or something. Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] reduce sizeof(struct file)Eric Dumazet2005-10-301-1/+1
| | | | | | | | | | | | | | | Now that RCU applied on 'struct file' seems stable, we can place f_rcuhead in a memory location that is not anymore used at call_rcu(&f->f_rcuhead, file_free_rcu) time, to reduce the size of this critical kernel object. The trick I used is to move f_rcuhead and f_list in an union called f_u The callers are changed so that f_rcuhead becomes f_u.fu_rcuhead and f_list becomes f_u.f_list Signed-off-by: Eric Dumazet <dada1@cosmosbay.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] proc: link count fixMiklos Szeredi2005-09-071-0/+13
| | | | | | | | | | | | | | | | This patch fixes bug titled "sunrpc as module and bad proc/sys link count" reported by Jiri Slaby. The problem was, that only proc_dir_entry->nlink was updated and the corresponding inode->i_nlink was not. The fix is to implement the inode->getattr() method, and update i_nlink (if necessary). A quick audit of proc code shows that no other attribute changes after creation. Signed-off-by: Miklos Szeredi <miklos@szeredi.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] Fix up symlink function pointersAl Viro2005-08-191-2/+2
| | | | | | | | | | This fixes up the symlink functions for the calling convention change: * afs, autofs4, befs, devfs, freevxfs, jffs2, jfs, ncpfs, procfs, smbfs, sysvfs, ufs, xfs - prototype change for ->follow_link() * befs, smbfs, xfs - same for ->put_link() Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* Linux-2.6.12-rc2v2.6.12-rc2Linus Torvalds2005-04-161-0/+705
Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
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