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* sysfs: Remove sysfs_get/put_active_twoEric W. Biederman2010-03-071-25/+25
| | | | | | | | | | | | | | | | It turns out that holding an active reference on a directory is pointless. The purpose of the active references are to allows us to block when removing sysfs entries that have custom methods so we don't remove modules while running modular code and to keep those custom methods from accessing data structures after the files have been removed. Further sysfs_remove_dir remove all elements in the directory before removing the directory itself, so there is no chance we will remove a directory with active children. Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> Cc: Tejun Heo <tj@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* Driver core: bin_attribute parameters can often be const*Phil Carmody2009-12-231-2/+4
| | | | | | | | | | | Many struct bin_attribute descriptors are purely read-only structures, and there's no need to change them. Therefore make the promise not to, which will let those descriptors be put in a ro section. Signed-off-by: Phil Carmody <ext-phil.2.carmody@nokia.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* const: mark struct vm_struct_operationsAlexey Dobriyan2009-09-271-2/+2
| | | | | | | | | | | * mark struct vm_area_struct::vm_ops as const * mark vm_ops in AGP code But leave TTM code alone, something is fishy there with global vm_ops being used. Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Free the memory allocated by memdup_user() in fs/sysfs/bin.cCatalin Marinas2009-07-081-0/+1
| | | | | | | | | | Commit 1c8542c7bb replaced kmalloc() with memdup_user() in the write() function but also dropped the kfree(temp). The memdup_user() function allocates memory which is never freed. Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Cc: Parag Warudkar <parag.warudkar@gmail.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* sysfs: use memdup_user()Li Zefan2009-04-201-10/+3
| | | | | | | Remove open-coded memdup_user(). Signed-off-by: Li Zefan <lizf@cn.fujitsu.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* mm: page_mkwrite change prototype to match fault: fix sysfsHugh Dickins2009-04-011-4/+4
| | | | | | | | | | | | | | | | Fix warnings and return values in sysfs bin_page_mkwrite(), fixing fs/sysfs/bin.c: In function `bin_page_mkwrite': fs/sysfs/bin.c:250: warning: passing argument 2 of `bb->vm_ops->page_mkwrite' from incompatible pointer type fs/sysfs/bin.c: At top level: fs/sysfs/bin.c:280: warning: initialization from incompatible pointer type Expects to have my [PATCH next] sysfs: fix some bin_vm_ops errors Signed-off-by: Hugh Dickins <hugh@veritas.com> Cc: Nick Piggin <npiggin@suse.de> Cc: "Eric W. Biederman" <ebiederm@aristanetworks.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* sysfs: fix some bin_vm_ops errorsHugh Dickins2009-03-241-10/+79
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Commit 86c9508eb1c0ce5aa07b5cf1d36b60c54efc3d7a "sysfs: don't block indefinitely for unmapped files" in linux-next crashes the PowerMac G5 when X starts up. It's caught out by the way powerpc's pci_mmap of legacy_mem uses shmem_zero_setup(), substituting a new vma->vm_file whose private_data no longer points to the bin_buffer (substitution done because some versions of X crash if that mmap fails). The fix to this is straightforward: the original vm_file is fput() in that case, so this mmap won't block sysfs at all, so just don't switch over to bin_vm_ops if vm_file has changed. But more fixes made before realizing that was the problem:- It should not be an error if bin_page_mkwrite() finds no underlying page_mkwrite(). Check that a file already mmap'ed has the same underlying vm_ops _before_ pointing vma->vm_ops at bin_vm_ops. If the file being mmap'ed is a shmem/tmpfs file, don't fail the mmap on CONFIG_NUMA=y, just because that has a set_policy and get_policy: provide bin_set_policy, bin_get_policy and bin_migrate. Signed-off-by: Hugh Dickins <hugh@veritas.com> Acked-by: Eric Biederman <ebiederm@aristanetworks.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* sysfs: don't block indefinitely for unmapped files.Eric W. Biederman2009-03-241-13/+171
| | | | | | | | | | | | | | | | | | | | Modify sysfs bin files so that we can remove the bin file while they are still mapped. When the kobject is removed we unmap the bin file and arrange for future accesses to the mapping to receive SIGBUS. Implementing this prevents a nasty DOS when pci devices are hot plugged and unplugged. Where if any of their resources were mmaped the kernel could not free up their pci resources or release their pci data structures. [akpm@linux-foundation.org: remove unused var] Signed-off-by: Eric W. Biederman <ebiederm@aristanetworks.com> Cc: Jesse Barnes <jbarnes@virtuousgeek.org> Acked-by: Tejun Heo <tj@kernel.org> Cc: Kay Sievers <kay.sievers@vrfy.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* sysfs: fix problems with binary filesGreg Kroah-Hartman2009-01-201-0/+6
| | | | | | | | | | | | Some sysfs binary files don't like having 0 passed to them as a size. Fix this up at the root by just returning to the vfs if userspace asks us for a zero sized buffer. Thanks to Pavel Roskin for pointing this out. Reported-by: Pavel Roskin <proski@gnu.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* sysfs: fix deadlockNick Piggin2008-10-161-11/+31
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | On Thu, Sep 11, 2008 at 10:27:10AM +0200, Ingo Molnar wrote: > and it's working fine on most boxes. One testbox found this new locking > scenario: > > PM: Adding info for No Bus:vcsa7 > EDAC DEBUG: MC0: i82860_check() > > ======================================================= > [ INFO: possible circular locking dependency detected ] > 2.6.27-rc6-tip #1 > ------------------------------------------------------- > X/4873 is trying to acquire lock: > (&bb->mutex){--..}, at: [<c020ba20>] mmap+0x40/0xa0 > > but task is already holding lock: > (&mm->mmap_sem){----}, at: [<c0125a1e>] sys_mmap2+0x8e/0xc0 > > which lock already depends on the new lock. > > > the existing dependency chain (in reverse order) is: > > -> #1 (&mm->mmap_sem){----}: > [<c017dc96>] validate_chain+0xa96/0xf50 > [<c017ef2b>] __lock_acquire+0x2cb/0x5b0 > [<c017f299>] lock_acquire+0x89/0xc0 > [<c01aa8fb>] might_fault+0x6b/0x90 > [<c040b618>] copy_to_user+0x38/0x60 > [<c020bcfb>] read+0xfb/0x170 > [<c01c09a5>] vfs_read+0x95/0x110 > [<c01c1443>] sys_pread64+0x63/0x80 > [<c012146f>] sysenter_do_call+0x12/0x43 > [<ffffffff>] 0xffffffff > > -> #0 (&bb->mutex){--..}: > [<c017d8b7>] validate_chain+0x6b7/0xf50 > [<c017ef2b>] __lock_acquire+0x2cb/0x5b0 > [<c017f299>] lock_acquire+0x89/0xc0 > [<c0d6f2ab>] __mutex_lock_common+0xab/0x3c0 > [<c0d6f698>] mutex_lock_nested+0x38/0x50 > [<c020ba20>] mmap+0x40/0xa0 > [<c01b111e>] mmap_region+0x14e/0x450 > [<c01b170f>] do_mmap_pgoff+0x2ef/0x310 > [<c0125a3d>] sys_mmap2+0xad/0xc0 > [<c012146f>] sysenter_do_call+0x12/0x43 > [<ffffffff>] 0xffffffff > > other info that might help us debug this: > > 1 lock held by X/4873: > #0: (&mm->mmap_sem){----}, at: [<c0125a1e>] sys_mmap2+0x8e/0xc0 > > stack backtrace: > Pid: 4873, comm: X Not tainted 2.6.27-rc6-tip #1 > [<c017cd09>] print_circular_bug_tail+0x79/0xc0 > [<c017d8b7>] validate_chain+0x6b7/0xf50 > [<c017a5b5>] ? trace_hardirqs_off_caller+0x15/0xb0 > [<c017ef2b>] __lock_acquire+0x2cb/0x5b0 > [<c017f299>] lock_acquire+0x89/0xc0 > [<c020ba20>] ? mmap+0x40/0xa0 > [<c0d6f2ab>] __mutex_lock_common+0xab/0x3c0 > [<c020ba20>] ? mmap+0x40/0xa0 > [<c0d6f698>] mutex_lock_nested+0x38/0x50 > [<c020ba20>] ? mmap+0x40/0xa0 > [<c020ba20>] mmap+0x40/0xa0 > [<c01b111e>] mmap_region+0x14e/0x450 > [<c01afb88>] ? arch_get_unmapped_area_topdown+0xf8/0x160 > [<c01b170f>] do_mmap_pgoff+0x2ef/0x310 > [<c0125a3d>] sys_mmap2+0xad/0xc0 > [<c012146f>] sysenter_do_call+0x12/0x43 > [<c0120000>] ? __switch_to+0x130/0x220 > ======================= > evbug.c: Event. Dev: input3, Type: 20, Code: 0, Value: 500 > warning: `sudo' uses deprecated v2 capabilities in a way that may be insecure. > > i've attached the config. > > at first sight it looks like a genuine bug in fs/sysfs/bin.c? Yes, it is a real bug by the looks. bin.c takes bb->mutex under mmap_sem when it is mmapped, and then does its copy_*_user under bb->mutex too. Here is a basic fix for the sysfs lor. From: Nick Piggin <npiggin@suse.de> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* sysfs: add copyrightsTejun Heo2007-10-121-1/+7
| | | | | | | | | Sysfs has gone through considerable amount of reimplementation. Add copyrights. Any objections? :-) Signed-off-by: Tejun Heo <htejun@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* sysfs: make s_elem an anonymous unionTejun Heo2007-10-121-7/+7
| | | | | | | | | | Make s_elem an anonymous union. Prefixing with s_elem makes things needlessly longer without any advantage. Signed-off-by: Tejun Heo <htejun@gmail.com> Acked-by: Cornelia Huck <cornelia.huck@de.ibm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* sysfs: make bin attr open get active reference of parent tooTejun Heo2007-10-121-5/+5
| | | | | | | | | | | | All bin attr operations require active references of itself and its parent. There's no reason to allow open when its parent has been deactivated and allowing it is inconsistent with regular sysfs file. Use sysfs_get_active_two() in bin attribute open function. Signed-off-by: Tejun Heo <htejun@gmail.com> Acked-by: Cornelia Huck <cornelia.huck@de.ibm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* sysfs: kill unnecessary sysfs_get() in open pathsTejun Heo2007-10-121-3/+1
| | | | | | | | | | | | | There's no reason to get an extra reference to sysfs_dirent for an open file. Open file has a reference to the dentry which in turn has a reference to sysfs_dirent. This is fairly obvious as otherwise open itself won't be able to access the sysfs_dirent. Kill the extra sysfs_get() and matching sysfs_put(). Signed-off-by: Tejun Heo <htejun@gmail.com> Acked-by: Cornelia Huck <cornelia.huck@de.ibm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* sysfs: cleanup semaphore.hDave Young2007-10-121-1/+1
| | | | | | | | | Cleanup semaphore.h Signed-off-by: Dave Young <hidave.darkstar@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* sysfs: don't warn on removal of a nonexistent binary fileAlan Stern2007-08-221-6/+1
| | | | | | | | | | | | | | This patch (as960) removes the error message and stack dump logged by sysfs_remove_bin_file() when someone tries to remove a nonexistent file. The warning doesn't seem to be needed, since none of the other file-, symlink-, or directory-removal routines in sysfs complain in a comparable way. Signed-off-by: Alan Stern <stern@rowland.harvard.edu> Acked-by: Tejun Heo <htejun@gmail.com> Acked-by: Cornelia Huck <cornelia.huck@de.ibm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* sysfs: add parameter "struct bin_attribute *" in .read/.write methods for ↵Zhang Rui2007-07-111-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | sysfs binary attributes Well, first of all, I don't want to change so many files either. What I do: Adding a new parameter "struct bin_attribute *" in the .read/.write methods for the sysfs binary attributes. In fact, only the four lines change in fs/sysfs/bin.c and include/linux/sysfs.h do the real work. But I have to update all the files that use binary attributes to make them compatible with the new .read and .write methods. I'm not sure if I missed any. :( Why I do this: For a sysfs attribute, we can get a pointer pointing to the struct attribute in the .show/.store method, while we can't do this for the binary attributes. I don't know why this is different, but this does make it not so handy to use the binary attributes as the regular ones. So I think this patch is reasonable. :) Who benefits from it: The patch that exposes ACPI tables in sysfs requires such an improvement. All the table binary attributes share the same .read method. Parameter "struct bin_attribute *" is used to get the table signature and instance number which are used to distinguish different ACPI table binary attributes. Without this parameter, we need to offer different .read methods for different ACPI table binary attributes. This is impossible as there are various ACPI tables on different platforms, and we don't know what they are until they are loaded. Signed-off-by: Zhang Rui <rui.zhang@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* sysfs: make kobj point to sysfs_dirent instead of dentryTejun Heo2007-07-111-3/+3
| | | | | | | | | | | | As kobj sysfs dentries and inodes are gonna be made reclaimable, dentry can't be used as naming token for sysfs file/directory, replace kobj->dentry with kobj->sd. The only external interface change is shadow directory handling. All other changes are contained in kobj and sysfs. Signed-off-by: Tejun Heo <htejun@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* sysfs: kill unnecessary attribute->ownerTejun Heo2007-07-111-14/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | sysfs is now completely out of driver/module lifetime game. After deletion, a sysfs node doesn't access anything outside sysfs proper, so there's no reason to hold onto the attribute owners. Note that often the wrong modules were accounted for as owners leading to accessing removed modules. This patch kills now unnecessary attribute->owner. Note that with this change, userland holding a sysfs node does not prevent the backing module from being unloaded. For more info regarding lifetime rule cleanup, please read the following message. http://article.gmane.org/gmane.linux.kernel/510293 (tweaked by Greg to not delete the field just yet, to make it easier to merge things properly.) Signed-off-by: Tejun Heo <htejun@gmail.com> Cc: Cornelia Huck <cornelia.huck@de.ibm.com> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* sysfs: implement sysfs_dirent active reference and immediate disconnectTejun Heo2007-07-111-33/+62
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | sysfs: implement sysfs_dirent active reference and immediate disconnect Opening a sysfs node references its associated kobject, so userland can arbitrarily prolong lifetime of a kobject which complicates lifetime rules in drivers. This patch implements active reference and makes the association between kobject and sysfs immediately breakable. Now each sysfs_dirent has two reference counts - s_count and s_active. s_count is a regular reference count which guarantees that the containing sysfs_dirent is accessible. As long as s_count reference is held, all sysfs internal fields in sysfs_dirent are accessible including s_parent and s_name. The newly added s_active is active reference count. This is acquired by invoking sysfs_get_active() and it's the caller's responsibility to ensure sysfs_dirent itself is accessible (should be holding s_count one way or the other). Dereferencing sysfs_dirent to access objects out of sysfs proper requires active reference. This includes access to the associated kobjects, attributes and ops. The active references can be drained and denied by calling sysfs_deactivate(). All active sysfs_dirents must be deactivated after deletion but before the default reference is dropped. This enables immediate disconnect of sysfs nodes. Once a sysfs_dirent is deleted, it won't access any entity external to sysfs proper. Because attr/bin_attr ops access both the node itself and its parent for kobject, they need to hold active references to both. sysfs_get/put_active_two() helpers are provided to help grabbing both references. Parent's is acquired first and released last. Unlike other operations, mmapped area lingers on after mmap() is finished and the module implement implementing it and kobj need to stay referenced till all the mapped pages are gone. This is accomplished by holding one set of active references to the bin_attr and its parent if there have been any mmap during lifetime of an openfile. The references are dropped when the openfile is released. This change makes sysfs lifetime rules independent from both kobject's and module's. It not only fixes several race conditions caused by sysfs not holding onto the proper module when referencing kobject, but also helps fixing and simplifying lifetime management in driver model and drivers by taking sysfs out of the equation. Please read the following message for more info. http://article.gmane.org/gmane.linux.kernel/510293 Signed-off-by: Tejun Heo <htejun@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* sysfs: implement bin_bufferTejun Heo2007-07-111-15/+49
| | | | | | | | | | Implement bin_buffer which contains a mutex and pointer to PAGE_SIZE buffer to properly synchronize accesses to per-openfile buffer and prepare for immediate-kobj-disconnect. Signed-off-by: Tejun Heo <htejun@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* sysfs: make sysfs_dirent->s_element a unionTejun Heo2007-07-111-7/+11
| | | | | | | | | | | | | | | | | | | | | Make sd->s_element a union of sysfs_elem_{dir|symlink|attr|bin_attr} and rename it to s_elem. This is to achieve... * some level of type checking : changing symlink to point to sysfs_dirent instead of kobject is much safer and less painful now. * easier / standardized dereferencing * allow sysfs_elem_* to contain more than one entry Where possible, pointer is obtained by directly deferencing from sd instead of going through other entities. This reduces dependencies to dentry, inode and kobject. to_attr() and to_bin_attr() are unused now and removed. This is in preparation of object reference simplification. Signed-off-by: Tejun Heo <htejun@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* sysfs: fix error handling in binattr write()Tejun Heo2007-07-111-14/+9
| | | | | | | | | | | | | Error handling in fs/sysfs/bin.c:write() was wrong because size_t count is used to receive return value from flush_write() which is negative on failure. This patch updates write() such that int variable is used instead. read() is updated the same way for consistency. Signed-off-by: Tejun Heo <htejun@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* sysfs: printk format warningRandy Dunlap2007-05-021-1/+1
| | | | | | | | | Fix sysfs printk format warning: fs/sysfs/bin.c:62: warning: format '%d' expects type 'int', but argument 4 has type 'size_t' Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* sysfs: bin.c printk fixAndrew Morton2007-04-271-1/+1
| | | | | | | | | | | fs/sysfs/bin.c: In function 'read': fs/sysfs/bin.c:77: warning: format '%zd' expects type 'signed size_t', but argument 4 has type 'int' Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* sysfs: kobject_put cleanupMariusz Kozlowski2007-02-071-3/+2
| | | | | | | | | This patch removes redundant argument checks for kobject_put(). Signed-off-by: Mariusz Kozlowski <m.kozlowski@tuxland.pl> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* Driver core: fix race in sysfs between sysfs_remove_file() and read()/write()Oliver Neukum2007-02-071-0/+1
| | | | | | | | | | | | | | This patch prevents a race between IO and removing a file from sysfs. It introduces a list of sysfs_buffers associated with a file at the inode. Upon removal of a file the list is walked and the buffers marked orphaned. IO to orphaned buffers fails with -ENODEV. The driver can safely free associated data structures or be unloaded. Signed-off-by: Oliver Neukum <oliver@neukum.name> Acked-by: Maneesh Soni <maneesh@in.ibm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* [PATCH] sysfs: change uses of f_{dentry, vfsmnt} to use f_pathJosef "Jeff" Sipek2006-12-081-7/+7
| | | | | | | | | Change all the uses of f_{dentry,vfsmnt} to f_path.{dentry,mnt} in the sysfs 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>
* sysfs_remove_bin_file: no return value, dump_stack on errorRandy.Dunlap2006-09-251-5/+8
| | | | | | | | | | | | | | | | Make sysfs_remove_bin_file() void. If it detects an error, printk the file name and call dump_stack(). sysfs_hash_and_remove() now returns an error code indicating its success or failure so that sysfs_remove_bin_file() can know success/failure. Convert the only driver that checked the return value of sysfs_remove_bin_file(). Signed-off-by: Randy Dunlap <rdunlap@xenotime.net> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* [PATCH] Make most file operations structs in fs/ constArjan van de Ven2006-03-281-1/+1
| | | | | | | | | | | | | | This is a conversion to make the various file_operations structs in fs/ const. Basically a regexp job, with a few manual fixups The goal is both to increase correctness (harder to accidentally write to shared datastructures) and reducing the false sharing of cachelines with things that get dirty in .data (while .rodata is nicely read only and thus cache clean) Signed-off-by: Arjan van de Ven <arjan@infradead.org> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] sysfs: if show/store is missing return -EIODmitry Torokhov2005-06-201-2/+2
| | | | | | | | sysfs: if attribute does not implement show or store method read/write should return -EIO instead of 0 or -EINVAL. Signed-off-by: Dmitry Torokhov <dtor@mail.ru> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* Linux-2.6.12-rc2Linus Torvalds2005-04-161-0/+204
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!