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2019-05-21treewide: Add SPDX license identifier - Makefile/KconfigThomas Gleixner1-0/+1
Add SPDX license identifiers to all Make/Kconfig files which: - Have no license information of any form These files fall under the project license, GPL v2 only. The resulting SPDX license identifier is: GPL-2.0-only Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-07Merge branch 'work.dcache' of ↵Linus Torvalds1-1/+1
git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull misc dcache updates from Al Viro: "Most of this pile is putting name length into struct name_snapshot and making use of it. The beginning of this series ("ovl_lookup_real_one(): don't bother with strlen()") ought to have been split in two (separate switch of name_snapshot to struct qstr from overlayfs reaping the trivial benefits of that), but I wanted to avoid a rebase - by the time I'd spotted that it was (a) in -next and (b) close to 5.1-final ;-/" * 'work.dcache' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: audit_compare_dname_path(): switch to const struct qstr * audit_update_watch(): switch to const struct qstr * inotify_handle_event(): don't bother with strlen() fsnotify: switch send_to_group() and ->handle_event to const struct qstr * fsnotify(): switch to passing const struct qstr * for file_name switch fsnotify_move() to passing const struct qstr * for old_name ovl_lookup_real_one(): don't bother with strlen() sysv: bury the broken "quietly truncate the long filenames" logics nsfs: unobfuscate unexport d_alloc_pseudo()
2019-05-07Merge tag 'driver-core-5.2-rc1' of ↵Linus Torvalds1-42/+35
git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core Pull driver core/kobject updates from Greg KH: "Here is the "big" set of driver core patches for 5.2-rc1 There are a number of ACPI patches in here as well, as Rafael said they should go through this tree due to the driver core changes they required. They have all been acked by the ACPI developers. There are also a number of small subsystem-specific changes in here, due to some changes to the kobject core code. Those too have all been acked by the various subsystem maintainers. As for content, it's pretty boring outside of the ACPI changes: - spdx cleanups - kobject documentation updates - default attribute groups for kobjects - other minor kobject/driver core fixes All have been in linux-next for a while with no reported issues" * tag 'driver-core-5.2-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: (47 commits) kobject: clean up the kobject add documentation a bit more kobject: Fix kernel-doc comment first line kobject: Remove docstring reference to kset firmware_loader: Fix a typo ("syfs" -> "sysfs") kobject: fix dereference before null check on kobj Revert "driver core: platform: Fix the usage of platform device name(pdev->name)" init/config: Do not select BUILD_BIN2C for IKCONFIG Provide in-kernel headers to make extending kernel easier kobject: Improve doc clarity kobject_init_and_add() kobject: Improve docs for kobject_add/del driver core: platform: Fix the usage of platform device name(pdev->name) livepatch: Replace klp_ktype_patch's default_attrs with groups cpufreq: schedutil: Replace default_attrs field with groups padata: Replace padata_attr_type default_attrs field with groups irqdesc: Replace irq_kobj_type's default_attrs field with groups net-sysfs: Replace ktype default_attrs field with groups block: Replace all ktype default_attrs with groups samples/kobject: Replace foo_ktype's default_attrs field with groups kobject: Add support for default attribute groups to kobj_type driver core: Postpone DMA tear-down until after devres release for probe failure ...
2019-05-01debugfs: switch to ->free_inode()Al Viro1-8/+2
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2019-04-26switch fsnotify_move() to passing const struct qstr * for old_nameAl Viro1-1/+1
note that in the second (RENAME_EXCHANGE) call of fsnotify_move() in vfs_rename() the old_dentry->d_name is guaranteed to be unchanged throughout the evaluation of fsnotify_move() (by the fact that the parent directory is locked exclusive), so we don't need to fetch old_dentry->d_name.name in the caller. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2019-04-26ovl_lookup_real_one(): don't bother with strlen()Al Viro1-1/+1
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2019-04-25debugfs: update documented return values of debugfs helpersRonald Tschalär1-42/+35
Since commit ff9fb72bc077 ("debugfs: return error values, not NULL") these helper functions do not return NULL anymore (with the exception of debugfs_create_u32_array()). Fixes: ff9fb72bc077 ("debugfs: return error values, not NULL") Signed-off-by: Ronald Tschalär <ronald@innovation.ch> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-04-01debugfs: fix use-after-free on symlink traversalAl Viro1-4/+9
symlink body shouldn't be freed without an RCU delay. Switch debugfs to ->destroy_inode() and use of call_rcu(); free both the inode and symlink body in the callback. Similar to solution for bpf, only here it's even more obvious that ->evict_inode() can be dropped. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2019-02-11Merge 5.0-rc6 into driver-core-nextGreg Kroah-Hartman1-12/+24
We need the debugfs fixes in here as well. Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-01-30debugfs: debugfs_lookup() should return NULL if not foundGreg Kroah-Hartman1-5/+5
Lots of callers of debugfs_lookup() were just checking NULL to see if the file/directory was found or not. By changing this in ff9fb72bc077 ("debugfs: return error values, not NULL") we caused some subsystems to easily crash. Fixes: ff9fb72bc077 ("debugfs: return error values, not NULL") Reported-by: syzbot+b382ba6a802a3d242790@syzkaller.appspotmail.com Reported-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Cc: Omar Sandoval <osandov@fb.com> Cc: Jens Axboe <axboe@fb.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-01-29debugfs: return error values, not NULLGreg Kroah-Hartman1-17/+22
When an error happens, debugfs should return an error pointer value, not NULL. This will prevent the totally theoretical error where a debugfs call fails due to lack of memory, returning NULL, and that dentry value is then passed to another debugfs call, which would end up succeeding, creating a file at the root of the debugfs tree, but would then be impossible to remove (because you can not remove the directory NULL). So, to make everyone happy, always return errors, this makes the users of debugfs much simpler (they do not have to ever check the return value), and everyone can rest easy. Reported-by: Gary R Hook <ghook@amd.com> Reported-by: Heiko Carstens <heiko.carstens@de.ibm.com> Reported-by: Masami Hiramatsu <mhiramat@kernel.org> Reported-by: Michal Hocko <mhocko@kernel.org> Reported-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Reported-by: Ulf Hansson <ulf.hansson@linaro.org> Reviewed-by: Masami Hiramatsu <mhiramat@kernel.org> Reviewed-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-01-25debugfs: fix debugfs_rename parameter checkingGreg Kroah-Hartman1-0/+7
debugfs_rename() needs to check that the dentries passed into it really are valid, as sometimes they are not (i.e. if the return value of another debugfs call is passed into this one.) So fix this up by properly checking if the two parent directories are errors (they are allowed to be NULL), and if the dentry to rename is not NULL or an error. Cc: stable <stable@vger.kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-01-22debugfs: debugfs_use_start/finish do not exist anymoreSergey Senozhatsky1-2/+2
debugfs_use_file_start() and debugfs_use_file_finish() do not exist since commit c9afbec27089 ("debugfs: purge obsolete SRCU based removal protection"); tweak debugfs_create_file_unsafe() comment. Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Reviewed-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-06-12Revert "debugfs: inode: debugfs_create_dir uses mode permission from parent"Linus Torvalds1-3/+1
This reverts commit 95cde3c59966f6371b6bcd9e4e2da2ba64ee9775. The commit had good intentions, but it breaks kvm-tool and qemu-kvm. With it in place, "lkvm run" just fails with Error: KVM_CREATE_VM ioctl Warning: Failed init: kvm__init which isn't a wonderful error message, but bisection pinpointed the problematic commit. The problem is almost certainly due to the special kvm debugfs entries created dynamically by kvm under /sys/kernel/debug/kvm/. See kvm_create_vm_debugfs() Bisected-and-reported-by: Linus Torvalds <torvalds@linux-foundation.org> Cc: Wanpeng Li <kernellwp@gmail.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Thomas Richter <tmricht@linux.ibm.com> Cc: Kees Cook <keescook@chromium.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-05-14debugfs: inode: debugfs_create_dir uses mode permission from parentThomas Richter1-1/+3
Currently function debugfs_create_dir() creates a new directory in the debugfs (usually mounted /sys/kernel/debug) with permission rwxr-xr-x. This is hard coded. Change this to use the parent directory permission. Output before the patch: root@s8360047 ~]# tree -dp -L 1 /sys/kernel/debug/ /sys/kernel/debug/ ├── [drwxr-xr-x] bdi ├── [drwxr-xr-x] block ├── [drwxr-xr-x] dasd ├── [drwxr-xr-x] device_component ├── [drwxr-xr-x] extfrag ├── [drwxr-xr-x] hid ├── [drwxr-xr-x] kprobes ├── [drwxr-xr-x] kvm ├── [drwxr-xr-x] memblock ├── [drwxr-xr-x] pm_qos ├── [drwxr-xr-x] qdio ├── [drwxr-xr-x] s390 ├── [drwxr-xr-x] s390dbf └── [drwx------] tracing 14 directories [root@s8360047 linux]# Output after the patch: [root@s8360047 ~]# tree -dp -L 1 /sys/kernel/debug/ sys/kernel/debug/ ├── [drwx------] bdi ├── [drwx------] block ├── [drwx------] dasd ├── [drwx------] device_component ├── [drwx------] extfrag ├── [drwx------] hid ├── [drwx------] kprobes ├── [drwx------] kvm ├── [drwx------] memblock ├── [drwx------] pm_qos ├── [drwx------] qdio ├── [drwx------] s390 ├── [drwx------] s390dbf └── [drwx------] tracing 14 directories [root@s8360047 linux]# Here is the full diff output done with: [root@s8360047 ~]# diff -u treefull.before treefull.after | sed 's-^- # -' > treefull.diff # --- treefull.before 2018-04-27 13:22:04.532824564 +0200 # +++ treefull.after 2018-04-27 13:24:12.106182062 +0200 # @@ -1,55 +1,55 @@ # /sys/kernel/debug/ # -├── [drwxr-xr-x] bdi # -│   ├── [drwxr-xr-x] 1:0 # -│   ├── [drwxr-xr-x] 1:1 # -│   ├── [drwxr-xr-x] 1:10 # -│   ├── [drwxr-xr-x] 1:11 # -│   ├── [drwxr-xr-x] 1:12 # -│   ├── [drwxr-xr-x] 1:13 # -│   ├── [drwxr-xr-x] 1:14 # -│   ├── [drwxr-xr-x] 1:15 # -│   ├── [drwxr-xr-x] 1:2 # -│   ├── [drwxr-xr-x] 1:3 # -│   ├── [drwxr-xr-x] 1:4 # -│   ├── [drwxr-xr-x] 1:5 # -│   ├── [drwxr-xr-x] 1:6 # -│   ├── [drwxr-xr-x] 1:7 # -│   ├── [drwxr-xr-x] 1:8 # -│   ├── [drwxr-xr-x] 1:9 # -│   └── [drwxr-xr-x] 94:0 # -├── [drwxr-xr-x] block # -├── [drwxr-xr-x] dasd # -│   ├── [drwxr-xr-x] 0.0.e18a # -│   ├── [drwxr-xr-x] dasda # -│   └── [drwxr-xr-x] global # -├── [drwxr-xr-x] device_component # -├── [drwxr-xr-x] extfrag # -├── [drwxr-xr-x] hid # -├── [drwxr-xr-x] kprobes # -├── [drwxr-xr-x] kvm # -├── [drwxr-xr-x] memblock # -├── [drwxr-xr-x] pm_qos # -├── [drwxr-xr-x] qdio # -│   └── [drwxr-xr-x] 0.0.f5f2 # -├── [drwxr-xr-x] s390 # -│   └── [drwxr-xr-x] stsi # -├── [drwxr-xr-x] s390dbf # -│   ├── [drwxr-xr-x] 0.0.e18a # -│   ├── [drwxr-xr-x] cio_crw # -│   ├── [drwxr-xr-x] cio_msg # -│   ├── [drwxr-xr-x] cio_trace # -│   ├── [drwxr-xr-x] dasd # -│   ├── [drwxr-xr-x] kvm-trace # -│   ├── [drwxr-xr-x] lgr # -│   ├── [drwxr-xr-x] qdio_0.0.f5f2 # -│   ├── [drwxr-xr-x] qdio_error # -│   ├── [drwxr-xr-x] qdio_setup # -│   ├── [drwxr-xr-x] qeth_card_0.0.f5f0 # -│   ├── [drwxr-xr-x] qeth_control # -│   ├── [drwxr-xr-x] qeth_msg # -│   ├── [drwxr-xr-x] qeth_setup # -│   ├── [drwxr-xr-x] vmcp # -│   └── [drwxr-xr-x] vmur # +├── [drwx------] bdi # +│   ├── [drwx------] 1:0 # +│   ├── [drwx------] 1:1 # +│   ├── [drwx------] 1:10 # +│   ├── [drwx------] 1:11 # +│   ├── [drwx------] 1:12 # +│   ├── [drwx------] 1:13 # +│   ├── [drwx------] 1:14 # +│   ├── [drwx------] 1:15 # +│   ├── [drwx------] 1:2 # +│   ├── [drwx------] 1:3 # +│   ├── [drwx------] 1:4 # +│   ├── [drwx------] 1:5 # +│   ├── [drwx------] 1:6 # +│   ├── [drwx------] 1:7 # +│   ├── [drwx------] 1:8 # +│   ├── [drwx------] 1:9 # +│   └── [drwx------] 94:0 # +├── [drwx------] block # +├── [drwx------] dasd # +│   ├── [drwx------] 0.0.e18a # +│   ├── [drwx------] dasda # +│   └── [drwx------] global # +├── [drwx------] device_component # +├── [drwx------] extfrag # +├── [drwx------] hid # +├── [drwx------] kprobes # +├── [drwx------] kvm # +├── [drwx------] memblock # +├── [drwx------] pm_qos # +├── [drwx------] qdio # +│   └── [drwx------] 0.0.f5f2 # +├── [drwx------] s390 # +│   └── [drwx------] stsi # +├── [drwx------] s390dbf # +│   ├── [drwx------] 0.0.e18a # +│   ├── [drwx------] cio_crw # +│   ├── [drwx------] cio_msg # +│   ├── [drwx------] cio_trace # +│   ├── [drwx------] dasd # +│   ├── [drwx------] kvm-trace # +│   ├── [drwx------] lgr # +│   ├── [drwx------] qdio_0.0.f5f2 # +│   ├── [drwx------] qdio_error # +│   ├── [drwx------] qdio_setup # +│   ├── [drwx------] qeth_card_0.0.f5f0 # +│   ├── [drwx------] qeth_control # +│   ├── [drwx------] qeth_msg # +│   ├── [drwx------] qeth_setup # +│   ├── [drwx------] vmcp # +│   └── [drwx------] vmur # └── [drwx------] tracing # ├── [drwxr-xr-x] events # │   ├── [drwxr-xr-x] alarmtimer Fixes: edac65eaf8d5c ("debugfs: take mode-dependent parts of debugfs_get_inode() into callers") Signed-off-by: Thomas Richter <tmricht@linux.ibm.com> Reviewed-by: Kees Cook <keescook@chromium.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-05-14debugfs: Re-use kstrtobool_from_user()Andy Shevchenko1-8/+2
Re-use kstrtobool_from_user() instead of open coded variant. Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-03-29debugfs_lookup(): switch to lookup_one_len_unlocked()Al Viro1-4/+1
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2018-02-11vfs: do bulk POLL* -> EPOLL* replacementLinus Torvalds1-1/+1
This is the mindless scripted replacement of kernel use of POLL* variables as described by Al, done by this script: for V in IN OUT PRI ERR RDNORM RDBAND WRNORM WRBAND HUP RDHUP NVAL MSG; do L=`git grep -l -w POLL$V | grep -v '^t' | grep -v /um/ | grep -v '^sa' | grep -v '/poll.h$'|grep -v '^D'` for f in $L; do sed -i "-es/^\([^\"]*\)\(\<POLL$V\>\)/\\1E\\2/" $f; done done with de-mangling cleanups yet to come. NOTE! On almost all architectures, the EPOLL* constants have the same values as the POLL* constants do. But they keyword here is "almost". For various bad reasons they aren't the same, and epoll() doesn't actually work quite correctly in some cases due to this on Sparc et al. The next patch from Al will sort out the final differences, and we should be all done. Scripted-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-02-01use linux/poll.h instead of asm/poll.hAl Viro1-1/+1
The only place that has any business including asm/poll.h is linux/poll.h. Fortunately, asm/poll.h had only been included in 3 places beyond that one, and all of them are trivial to switch to using linux/poll.h. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2017-11-27fs: annotate ->poll() instancesAl Viro1-1/+1
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2017-11-27anntotate the places where ->poll() return values goAl Viro1-1/+1
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2017-11-07debugfs: Remove redundant license textGreg Kroah-Hartman3-15/+0
Now that the SPDX tag is in all debugfs files, that identifies the license in a specific and legally-defined manner. So the extra GPL text wording can be removed as it is no longer needed at all. This is done on a quest to remove the 700+ different ways that files in the kernel describe the GPL license text. And there's unneeded stuff like the address (sometimes incorrect) for the FSF which is never needed. No copyright headers or other non-license-description text was removed. Cc: Nicolai Stange <nicstange@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-11-07debugfs: add SPDX identifiers to all debugfs filesGreg Kroah-Hartman3-0/+3
It's good to have SPDX identifiers in all files to make it easier to audit the kernel tree for correct licenses. Update the debugfs files files with the correct SPDX license identifier based on the license text in the file itself. The SPDX identifier is a legally binding shorthand, which can be used instead of the full boiler plate text. This work is based on a script and data from Thomas Gleixner, Philippe Ombredanne, and Kate Stewart. Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Kate Stewart <kstewart@linuxfoundation.org> Cc: Philippe Ombredanne <pombredanne@nexb.com> Cc: Nicolai Stange <nicstange@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-11-07debugfs: defer debugfs_fsdata allocation to first usageNicolai Stange3-26/+73
Currently, __debugfs_create_file allocates one struct debugfs_fsdata instance for every file created. However, there are potentially many debugfs file around, most of which are never touched by userspace. Thus, defer the allocations to the first usage, i.e. to the first debugfs_file_get(). A dentry's ->d_fsdata starts out to point to the "real", user provided fops. After a debugfs_fsdata instance has been allocated (and the real fops pointer has been moved over into its ->real_fops member), ->d_fsdata is changed to point to it from then on. The two cases are distinguished by setting BIT(0) for the real fops case. struct debugfs_fsdata's foremost purpose is to track active users and to make debugfs_remove() block until they are done. Since no debugfs_fsdata instance means no active users, make debugfs_remove() return immediately in this case. Take care of possible races between debugfs_file_get() and debugfs_remove(): either debugfs_remove() must see a debugfs_fsdata instance and thus wait for possible active users or debugfs_file_get() must see a dead dentry and return immediately. Make a dentry's ->d_release(), i.e. debugfs_release_dentry(), check whether ->d_fsdata is actually a debugfs_fsdata instance before kfree()ing it. Similarly, make debugfs_real_fops() check whether ->d_fsdata is actually a debugfs_fsdata instance before returning it, otherwise emit a warning. The set of possible error codes returned from debugfs_file_get() has grown from -EIO to -EIO and -ENOMEM. Make open_proxy_open() and full_proxy_open() pass the -ENOMEM onwards to their callers. Signed-off-by: Nicolai Stange <nicstange@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-11-07debugfs: call debugfs_real_fops() only after debugfs_file_get()Nicolai Stange1-3/+4
The current implementation of debugfs_real_fops() relies on a debugfs_fsdata instance to be installed at ->d_fsdata. With future patches introducing lazy allocation of these, this requirement will be guaranteed to be fullfilled only inbetween a debugfs_file_get()/debugfs_file_put() pair. The full proxies' fops implemented by debugfs happen to be the only offenders. Fix them up by moving their debugfs_real_fops() calls past those to debugfs_file_get(). full_proxy_release() is special as it doesn't invoke debugfs_file_get() at all. Leave it alone for now. Signed-off-by: Nicolai Stange <nicstange@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-11-07debugfs: purge obsolete SRCU based removal protectionNicolai Stange2-55/+0
Purge the SRCU based file removal race protection in favour of the new, refcount based debugfs_file_get()/debugfs_file_put() API. Fixes: 49d200deaa68 ("debugfs: prevent access to removed files' private data") Signed-off-by: Nicolai Stange <nicstange@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-11-07debugfs: convert to debugfs_file_get() and -put()Nicolai Stange1-56/+50
Convert all calls to the now obsolete debugfs_use_file_start() and debugfs_use_file_finish() from the debugfs core itself to the new debugfs_file_get() and debugfs_file_put() API. Fixes: 49d200deaa68 ("debugfs: prevent access to removed files' private data") Signed-off-by: Nicolai Stange <nicstange@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-11-07debugfs: debugfs_real_fops(): drop __must_hold sparse annotationNicolai Stange1-5/+1
Currently, debugfs_real_fops() is annotated with a __must_hold(&debugfs_srcu) sparse annotation. With the conversion of the SRCU based protection of users against concurrent file removals to a per-file refcount based scheme, this becomes wrong. Drop this annotation. Signed-off-by: Nicolai Stange <nicstange@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-11-07debugfs: implement per-file removal protectionNicolai Stange3-6/+73
Since commit 49d200deaa68 ("debugfs: prevent access to removed files' private data"), accesses to a file's private data are protected from concurrent removal by covering all file_operations with a SRCU read section and sychronizing with those before returning from debugfs_remove() by means of synchronize_srcu(). As pointed out by Johannes Berg, there are debugfs files with forever blocking file_operations. Their corresponding SRCU read side sections would block any debugfs_remove() forever as well, even unrelated ones. This results in a livelock. Because a remover can't cancel any indefinite blocking within foreign files, this is a problem. Resolve this by introducing support for more granular protection on a per-file basis. This is implemented by introducing an 'active_users' refcount_t to the per-file struct debugfs_fsdata state. At file creation time, it is set to one and a debugfs_remove() will drop that initial reference. The new debugfs_file_get() and debugfs_file_put(), intended to be used in place of former debugfs_use_file_start() and debugfs_use_file_finish(), increment and decrement it respectively. Once the count drops to zero, debugfs_file_put() will signal a completion which is possibly being waited for from debugfs_remove(). Thus, as long as there is a debugfs_file_get() not yet matched by a corresponding debugfs_file_put() around, debugfs_remove() will block. Actual users of debugfs_use_file_start() and -finish() will get converted to the new debugfs_file_get() and debugfs_file_put() by followup patches. Fixes: 49d200deaa68 ("debugfs: prevent access to removed files' private data") Reported-by: Johannes Berg <johannes@sipsolutions.net> Signed-off-by: Nicolai Stange <nicstange@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-11-07debugfs: add support for more elaborate ->d_fsdataNicolai Stange3-3/+35
Currently, the user provided fops, "real_fops", are stored directly into ->d_fsdata. In order to be able to store more per-file state and thus prepare for more granular file removal protection, wrap the real_fops into a dynamically allocated container struct, debugfs_fsdata. A struct debugfs_fsdata gets allocated at file creation and freed from the newly intoduced ->d_release(). Finally, move the implementation of debugfs_real_fops() out of the public debugfs header such that struct debugfs_fsdata's declaration can be kept private. Signed-off-by: Nicolai Stange <nicstange@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-15Merge branch 'work.mount' of ↵Linus Torvalds1-2/+0
git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull ->s_options removal from Al Viro: "Preparations for fsmount/fsopen stuff (coming next cycle). Everything gets moved to explicit ->show_options(), killing ->s_options off + some cosmetic bits around fs/namespace.c and friends. Basically, the stuff needed to work with fsmount series with minimum of conflicts with other work. It's not strictly required for this merge window, but it would reduce the PITA during the coming cycle, so it would be nice to have those bits and pieces out of the way" * 'work.mount' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: isofs: Fix isofs_show_options() VFS: Kill off s_options and helpers orangefs: Implement show_options 9p: Implement show_options isofs: Implement show_options afs: Implement show_options affs: Implement show_options befs: Implement show_options spufs: Implement show_options bpf: Implement show_options ramfs: Implement show_options pstore: Implement show_options omfs: Implement show_options hugetlbfs: Implement show_options VFS: Don't use save/replace_mount_options if not using generic_show_options VFS: Provide empty name qstr VFS: Make get_filesystem() return the affected filesystem VFS: Clean up whitespace in fs/namespace.c and fs/super.c Provide a function to create a NUL-terminated string from unterminated data
2017-07-08Merge branch 'work.misc' of ↵Linus Torvalds1-5/+5
git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull misc filesystem updates from Al Viro: "Assorted normal VFS / filesystems stuff..." * 'work.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: dentry name snapshots Make statfs properly return read-only state after emergency remount fs/dcache: init in_lookup_hashtable minix: Deinline get_block, save 2691 bytes fs: Reorder inode_owner_or_capable() to avoid needless fs: warn in case userspace lied about modprobe return
2017-07-07dentry name snapshotsAl Viro1-5/+5
take_dentry_name_snapshot() takes a safe snapshot of dentry name; if the name is a short one, it gets copied into caller-supplied structure, otherwise an extra reference to external name is grabbed (those are never modified). In either case the pointer to stable string is stored into the same structure. dentry must be held by the caller of take_dentry_name_snapshot(), but may be freely dropped afterwards - the snapshot will stay until destroyed by release_dentry_name_snapshot(). Intended use: struct name_snapshot s; take_dentry_name_snapshot(&s, dentry); ... access s.name ... release_dentry_name_snapshot(&s); Replaces fsnotify_oldname_...(), gets used in fsnotify to obtain the name to pass down with event. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2017-07-06VFS: Don't use save/replace_mount_options if not using generic_show_optionsDavid Howells1-2/+0
btrfs, debugfs, reiserfs and tracefs call save_mount_options() and reiserfs calls replace_mount_options(), but they then implement their own ->show_options() methods and don't touch s_options, rendering the saved options unnecessary. I'm trying to eliminate s_options to make it easier to implement a context-based mount where the mount options can be passed individually over a file descriptor. Remove the calls to save/replace_mount_options() call in these cases. Signed-off-by: David Howells <dhowells@redhat.com> cc: Chris Mason <clm@fb.com> cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> cc: Steven Rostedt <rostedt@goodmis.org> cc: linux-btrfs@vger.kernel.org cc: reiserfs-devel@vger.kernel.org Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2017-05-16fs: fix the location of the kernel-api bookMauro Carvalho Chehab1-1/+1
The kernel-api book is now part of the core-api. Update its location. Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2017-05-16fs: update location of filesystems documentationMauro Carvalho Chehab1-1/+1
The filesystem documentation was moved from DocBook to Documentation/filesystems/. Update it at the sources. Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2017-04-26fs: constify tree_descr arrays passed to simple_fill_super()Eric Biggers1-1/+1
simple_fill_super() is passed an array of tree_descr structures which describe the files to create in the filesystem's root directory. Since these arrays are never modified intentionally, they should be 'const' so that they are placed in .rodata and benefit from memory protection. This patch updates the function signature and all users, and also constifies tree_descr.name. Signed-off-by: Eric Biggers <ebiggers@google.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2017-02-23Merge branch 'for-linus' of ↵Linus Torvalds1-4/+4
git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace Pull namespace updates from Eric Biederman: "There is a lot here. A lot of these changes result in subtle user visible differences in kernel behavior. I don't expect anything will care but I will revert/fix things immediately if any regressions show up. From Seth Forshee there is a continuation of the work to make the vfs ready for unpriviled mounts. We had thought the previous changes prevented the creation of files outside of s_user_ns of a filesystem, but it turns we missed the O_CREAT path. Ooops. Pavel Tikhomirov and Oleg Nesterov worked together to fix a long standing bug in the implemenation of PR_SET_CHILD_SUBREAPER where only children that are forked after the prctl are considered and not children forked before the prctl. The only known user of this prctl systemd forks all children after the prctl. So no userspace regressions will occur. Holding earlier forked children to the same rules as later forked children creates a semantic that is sane enough to allow checkpoing of processes that use this feature. There is a long delayed change by Nikolay Borisov to limit inotify instances inside a user namespace. Michael Kerrisk extends the API for files used to maniuplate namespaces with two new trivial ioctls to allow discovery of the hierachy and properties of namespaces. Konstantin Khlebnikov with the help of Al Viro adds code that when a network namespace exits purges it's sysctl entries from the dcache. As in some circumstances this could use a lot of memory. Vivek Goyal fixed a bug with stacked filesystems where the permissions on the wrong inode were being checked. I continue previous work on ptracing across exec. Allowing a file to be setuid across exec while being ptraced if the tracer has enough credentials in the user namespace, and if the process has CAP_SETUID in it's own namespace. Proc files for setuid or otherwise undumpable executables are now owned by the root in the user namespace of their mm. Allowing debugging of setuid applications in containers to work better. A bug I introduced with permission checking and automount is now fixed. The big change is to mark the mounts that the kernel initiates as a result of an automount. This allows the permission checks in sget to be safely suppressed for this kind of mount. As the permission check happened when the original filesystem was mounted. Finally a special case in the mount namespace is removed preventing unbounded chains in the mount hash table, and making the semantics simpler which benefits CRIU. The vfs fix along with related work in ima and evm I believe makes us ready to finish developing and merge fully unprivileged mounts of the fuse filesystem. The cleanups of the mount namespace makes discussing how to fix the worst case complexity of umount. The stacked filesystem fixes pave the way for adding multiple mappings for the filesystem uids so that efficient and safer containers can be implemented" * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace: proc/sysctl: Don't grab i_lock under sysctl_lock. vfs: Use upper filesystem inode in bprm_fill_uid() proc/sysctl: prune stale dentries during unregistering mnt: Tuck mounts under others instead of creating shadow/side mounts. prctl: propagate has_child_subreaper flag to every descendant introduce the walk_process_tree() helper nsfs: Add an ioctl() to return owner UID of a userns fs: Better permission checking for submounts exit: fix the setns() && PR_SET_CHILD_SUBREAPER interaction vfs: open() with O_CREAT should not create inodes with unknown ids nsfs: Add an ioctl() to return the namespace type proc: Better ownership of files for non-dumpable tasks in user namespaces exec: Remove LSM_UNSAFE_PTRACE_CAP exec: Test the ptracer's saved cred to see if the tracee can gain caps exec: Don't reset euid and egid when the tracee has CAP_SETUID inotify: Convert to using per-namespace limits
2017-02-02debugfs: add debugfs_lookup()Omar Sandoval1-0/+36
We don't always have easy access to the dentry of a file or directory we created in debugfs. Add a helper which allows us to get a dentry we previously created. The motivation for this change is a problem with blktrace and the blk-mq debugfs entries introduced in 07e4fead45e6 ("blk-mq: create debugfs directory tree"). Namely, in some cases, the directory that blktrace needs to create may already exist, but in other cases, it may not. We _could_ rely on a bunch of implied knowledge to decide whether to create the directory or not, but it's much cleaner on our end to just look it up. Signed-off-by: Omar Sandoval <osandov@fb.com> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Jens Axboe <axboe@fb.com>
2017-02-02fs: Better permission checking for submountsEric W. Biederman1-4/+4
To support unprivileged users mounting filesystems two permission checks have to be performed: a test to see if the user allowed to create a mount in the mount namespace, and a test to see if the user is allowed to access the specified filesystem. The automount case is special in that mounting the original filesystem grants permission to mount the sub-filesystems, to any user who happens to stumble across the their mountpoint and satisfies the ordinary filesystem permission checks. Attempting to handle the automount case by using override_creds almost works. It preserves the idea that permission to mount the original filesystem is permission to mount the sub-filesystem. Unfortunately using override_creds messes up the filesystems ordinary permission checks. Solve this by being explicit that a mount is a submount by introducing vfs_submount, and using it where appropriate. vfs_submount uses a new mount internal mount flags MS_SUBMOUNT, to let sget and friends know that a mount is a submount so they can take appropriate action. sget and sget_userns are modified to not perform any permission checks on submounts. follow_automount is modified to stop using override_creds as that has proven problemantic. do_mount is modified to always remove the new MS_SUBMOUNT flag so that we know userspace will never by able to specify it. autofs4 is modified to stop using current_real_cred that was put in there to handle the previous version of submount permission checking. cifs is modified to pass the mountpoint all of the way down to vfs_submount. debugfs is modified to pass the mountpoint all of the way down to trace_automount by adding a new parameter. To make this change easier a new typedef debugfs_automount_t is introduced to capture the type of the debugfs automount function. Cc: stable@vger.kernel.org Fixes: 069d5ac9ae0d ("autofs: Fix automounts by using current_real_cred()->uid") Fixes: aeaa4a79ff6a ("fs: Call d_automount with the filesystems creds") Reviewed-by: Trond Myklebust <trond.myklebust@primarydata.com> Reviewed-by: Seth Forshee <seth.forshee@canonical.com> Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2016-10-10Merge branch 'for-linus' of ↵Linus Torvalds1-2/+2
git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull more vfs updates from Al Viro: ">rename2() work from Miklos + current_time() from Deepa" * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: fs: Replace current_fs_time() with current_time() fs: Replace CURRENT_TIME_SEC with current_time() for inode timestamps fs: Replace CURRENT_TIME with current_time() for inode timestamps fs: proc: Delete inode time initializations in proc_alloc_inode() vfs: Add current_time() api vfs: add note about i_op->rename changes to porting fs: rename "rename2" i_op to "rename" vfs: remove unused i_op->rename fs: make remaining filesystems use .rename2 libfs: support RENAME_NOREPLACE in simple_rename() fs: support RENAME_NOREPLACE for local filesystems ncpfs: fix unused variable warning
2016-10-10Merge remote-tracking branch 'ovl/rename2' into for-linusAl Viro1-1/+1
2016-09-27fs: Replace current_fs_time() with current_time()Deepa Dinamani1-1/+1
current_fs_time() uses struct super_block* as an argument. As per Linus's suggestion, this is changed to take struct inode* as a parameter instead. This is because the function is primarily meant for vfs inode timestamps. Also the function was renamed as per Arnd's suggestion. Change all calls to current_fs_time() to use the new current_time() function instead. current_fs_time() will be deleted. Signed-off-by: Deepa Dinamani <deepa.kernel@gmail.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-09-27debugfs: propagate release() call resultEric Engestrom1-1/+1
The result was being ignored and 0 was always returned. Return the actual result instead. Signed-off-by: Eric Engestrom <eric.engestrom@imgtec.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-09-27libfs: support RENAME_NOREPLACE in simple_rename()Miklos Szeredi1-1/+1
This is trivial to do: - add flags argument to simple_rename() - check if flags doesn't have any other than RENAME_NOREPLACE - assign simple_rename() to .rename2 instead of .rename Filesystems converted: hugetlbfs, ramfs, bpf. Debugfs uses simple_rename() to implement debugfs_rename(), which is for debugfs instances to rename files internally, not for userspace filesystem access. For this case pass zero flags to simple_rename(). Signed-off-by: Miklos Szeredi <mszeredi@redhat.com> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Alexei Starovoitov <ast@kernel.org>
2016-09-21debugfs: introduce a public file_operations accessorChristian Lamparter1-8/+5
This patch introduces an accessor which can be used by the users of debugfs (drivers, fs, ...) to get the original file_operations struct. It also removes the REAL_FOPS_DEREF macro in file.c and converts the code to use the public version. Previously, REAL_FOPS_DEREF was only available within the file.c of debugfs. But having a public getter available for debugfs users is important as some drivers (carl9170 and b43) use the pointer of the original file_operations in conjunction with container_of() within their debugfs implementations. Reviewed-by: Nicolai Stange <nicstange@gmail.com> Signed-off-by: Christian Lamparter <chunkeey@gmail.com> Cc: stable <stable@vger.kernel.org> # 4.7+ Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-08-31debugfs: remove extra debugfs_create_file_unsafe() declarationNicolai Stange1-4/+0
debugfs_create_file_unsafe() is declared twice in exactly the same manner each: once in fs/debugfs/internal.h and once in include/linux/debugfs.h All files that include the former also include the latter and thus, the declaration in fs/debugfs/internal.h is superfluous. Remove it. Signed-off-by: Nicolai Stange <nicstange@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-06-30Merge branch 'd_real' of ↵Al Viro1-3/+4
git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/vfs into work.misc
2016-06-15debugfs: open_proxy_open(): avoid double fops releaseNicolai Stange1-1/+0
Debugfs' open_proxy_open(), the ->open() installed at all inodes created through debugfs_create_file_unsafe(), - grabs a reference to the original file_operations instance passed to debugfs_create_file_unsafe() via fops_get(), - installs it at the file's ->f_op by means of replace_fops() - and calls fops_put() on it. Since the semantics of replace_fops() are such that the reference's ownership is transferred, the subsequent fops_put() will result in a double release when the file is eventually closed. Currently, this is not an issue since fops_put() basically does a module_put() on the file_operations' ->owner only and there don't exist any modules calling debugfs_create_file_unsafe() yet. This is expected to change in the future though, c.f. commit c64688081490 ("debugfs: add support for self-protecting attribute file fops"). Remove the call to fops_put() from open_proxy_open(). Fixes: 9fd4dcece43a ("debugfs: prevent access to possibly dead file_operations at file open") Signed-off-by: Nicolai Stange <nicstange@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-06-15debugfs: full_proxy_open(): free proxy on ->open() failureNicolai Stange1-2/+4
Debugfs' full_proxy_open(), the ->open() installed at all inodes created through debugfs_create_file(), - grabs a reference to the original struct file_operations instance passed to debugfs_create_file(), - dynamically allocates a proxy struct file_operations instance wrapping the original - and installs this at the file's ->f_op. Afterwards, it calls the original ->open() and passes its return value back to the VFS layer. Now, if that return value indicates failure, the VFS layer won't ever call ->release() and thus, neither the reference to the original file_operations nor the memory for the proxy file_operations will get released, i.e. both are leaked. Upon failure of the original fops' ->open(), undo the proxy installation. That is: - Set the struct file ->f_op to what it had been when full_proxy_open() was entered. - Drop the reference to the original file_operations. - Free the memory holding the proxy file_operations. Fixes: 49d200deaa68 ("debugfs: prevent access to removed files' private data") Signed-off-by: Nicolai Stange <nicstange@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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