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2019-12-06Merge branch 'fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfsLinus Torvalds1-5/+1
Pull vfs d_inode/d_flags memory ordering fixes from Al Viro: "Fallout from tree-wide audit for ->d_inode/->d_flags barriers use. Basically, the problem is that negative pinned dentries require careful treatment - unless ->d_lock is locked or parent is held at least shared, another thread can make them positive right under us. Most of the uses turned out to be safe - the main surprises as far as filesystems are concerned were - race in dget_parent() fastpath, that might end up with the caller observing the returned dentry _negative_, due to insufficient barriers. It is positive in memory, but we could end up seeing the wrong value of ->d_inode in CPU cache. Fixed. - manual checks that result of lookup_one_len_unlocked() is positive (and rejection of negatives). Again, insufficient barriers (we might end up with inconsistent observed values of ->d_inode and ->d_flags). Fixed by switching to a new primitive that does the checks itself and returns ERR_PTR(-ENOENT) instead of a negative dentry. That way we get rid of boilerplate converting negatives into ERR_PTR(-ENOENT) in the callers and have a single place to deal with the barrier-related mess - inside fs/namei.c rather than in every caller out there. The guts of pathname resolution *do* need to be careful - the race found by Ritesh is real, as well as several similar races. Fortunately, it turns out that we can take care of that with fairly local changes in there. The tree-wide audit had not been fun, and I hate the idea of repeating it. I think the right approach would be to annotate the places where we are _not_ guaranteed ->d_inode/->d_flags stability and have sparse catch regressions. But I'm still not sure what would be the least invasive way of doing that and it's clearly the next cycle fodder" * 'fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: fs/namei.c: fix missing barriers when checking positivity fix dget_parent() fastpath race new helper: lookup_positive_unlocked() fs/namei.c: pull positivity check into follow_managed()
2019-11-15new helper: lookup_positive_unlocked()Al Viro1-5/+1
Most of the callers of lookup_one_len_unlocked() treat negatives are ERR_PTR(-ENOENT). Provide a helper that would do just that. Note that a pinned positive dentry remains positive - it's ->d_inode is stable, etc.; a pinned _negative_ dentry can become positive at any point as long as you are not holding its parent at least shared. So using lookup_one_len_unlocked() needs to be careful; lookup_positive_unlocked() is safer and that's what the callers end up open-coding anyway. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2019-11-03debugfs: remove return value of debugfs_create_atomic_t()Greg Kroah-Hartman1-5/+4
No one checks the return value of debugfs_create_atomic_t(), as it's not needed, so make the return value void, so that no one tries to do so in the future. Link: https://lore.kernel.org/r/20191016130332.GA28240@kroah.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-11-02debugfs: remove return value of debugfs_create_x8()Greg Kroah-Hartman1-3/+3
No one checks the return value of debugfs_create_x8(), as it's not needed, so make the return value void, so that no one tries to do so in the future. Link: https://lore.kernel.org/r/20191011132931.1186197-5-gregkh@linuxfoundation.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-10-16debugfs: remove return value of debugfs_create_x64()Greg Kroah-Hartman1-3/+3
No one checks the return value of debugfs_create_x64(), as it's not needed, so make the return value void, so that no one tries to do so in the future. Link: https://lore.kernel.org/r/20191011132931.1186197-8-gregkh@linuxfoundation.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-10-16debugfs: remove return value of debugfs_create_x32()Greg Kroah-Hartman1-3/+3
No one checks the return value of debugfs_create_x32(), as it's not needed, so make the return value void, so that no one tries to do so in the future. Link: https://lore.kernel.org/r/20191011132931.1186197-7-gregkh@linuxfoundation.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-10-16debugfs: remove return value of debugfs_create_x16()Greg Kroah-Hartman1-3/+3
No one checks the return value of debugfs_create_x16(), as it's not needed, so make the return value void, so that no one tries to do so in the future. Link: https://lore.kernel.org/r/20191011132931.1186197-6-gregkh@linuxfoundation.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-10-14debugfs: remove return value of debugfs_create_size_t()Greg Kroah-Hartman1-5/+4
No one checks the return value of debugfs_create_size_t(), as it's not needed, so make the return value void, so that no one tries to do so in the future. Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Link: https://lore.kernel.org/r/20191011132931.1186197-4-gregkh@linuxfoundation.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-10-14debugfs: remove return value of debugfs_create_u64()Greg Kroah-Hartman1-12/+3
No one checks the return value of debugfs_create_u64(), as it's not needed, so make the return value void, so that no one tries to do so in the future. Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Link: https://lore.kernel.org/r/20191011132931.1186197-3-gregkh@linuxfoundation.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-10-14debugfs: remove return value of debugfs_create_u16()Greg Kroah-Hartman1-12/+3
No one checks the return value of debugfs_create_u16(), as it's not needed, so make the return value void, so that no one tries to do so in the future. Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Link: https://lore.kernel.org/r/20191011132931.1186197-2-gregkh@linuxfoundation.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-10-14debugfs: remove return value of debugfs_create_u8()Greg Kroah-Hartman1-12/+3
No one checks the return value of debugfs_create_u8(), as it's not needed, so make the return value void, so that no one tries to do so in the future. Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Link: https://lore.kernel.org/r/20191011132931.1186197-1-gregkh@linuxfoundation.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-09-28Merge branch 'next-lockdown' of ↵Linus Torvalds2-2/+60
git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security Pull kernel lockdown mode from James Morris: "This is the latest iteration of the kernel lockdown patchset, from Matthew Garrett, David Howells and others. From the original description: This patchset introduces an optional kernel lockdown feature, intended to strengthen the boundary between UID 0 and the kernel. When enabled, various pieces of kernel functionality are restricted. Applications that rely on low-level access to either hardware or the kernel may cease working as a result - therefore this should not be enabled without appropriate evaluation beforehand. The majority of mainstream distributions have been carrying variants of this patchset for many years now, so there's value in providing a doesn't meet every distribution requirement, but gets us much closer to not requiring external patches. There are two major changes since this was last proposed for mainline: - Separating lockdown from EFI secure boot. Background discussion is covered here: https://lwn.net/Articles/751061/ - Implementation as an LSM, with a default stackable lockdown LSM module. This allows the lockdown feature to be policy-driven, rather than encoding an implicit policy within the mechanism. The new locked_down LSM hook is provided to allow LSMs to make a policy decision around whether kernel functionality that would allow tampering with or examining the runtime state of the kernel should be permitted. The included lockdown LSM provides an implementation with a simple policy intended for general purpose use. This policy provides a coarse level of granularity, controllable via the kernel command line: lockdown={integrity|confidentiality} Enable the kernel lockdown feature. If set to integrity, kernel features that allow userland to modify the running kernel are disabled. If set to confidentiality, kernel features that allow userland to extract confidential information from the kernel are also disabled. This may also be controlled via /sys/kernel/security/lockdown and overriden by kernel configuration. New or existing LSMs may implement finer-grained controls of the lockdown features. Refer to the lockdown_reason documentation in include/linux/security.h for details. The lockdown feature has had signficant design feedback and review across many subsystems. This code has been in linux-next for some weeks, with a few fixes applied along the way. Stephen Rothwell noted that commit 9d1f8be5cf42 ("bpf: Restrict bpf when kernel lockdown is in confidentiality mode") is missing a Signed-off-by from its author. Matthew responded that he is providing this under category (c) of the DCO" * 'next-lockdown' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security: (31 commits) kexec: Fix file verification on S390 security: constify some arrays in lockdown LSM lockdown: Print current->comm in restriction messages efi: Restrict efivar_ssdt_load when the kernel is locked down tracefs: Restrict tracefs when the kernel is locked down debugfs: Restrict debugfs when the kernel is locked down kexec: Allow kexec_file() with appropriate IMA policy when locked down lockdown: Lock down perf when in confidentiality mode bpf: Restrict bpf when kernel lockdown is in confidentiality mode lockdown: Lock down tracing and perf kprobes when in confidentiality mode lockdown: Lock down /proc/kcore x86/mmiotrace: Lock down the testmmiotrace module lockdown: Lock down module params that specify hardware parameters (eg. ioport) lockdown: Lock down TIOCSSERIAL lockdown: Prohibit PCMCIA CIS storage when the kernel is locked down acpi: Disable ACPI table override if the kernel is locked down acpi: Ignore acpi_rsdp kernel param when the kernel has been locked down ACPI: Limit access to custom_method when the kernel is locked down x86/msr: Restrict MSR access when the kernel is locked down x86: Lock down IO port access when the kernel is locked down ...
2019-08-19debugfs: Restrict debugfs when the kernel is locked downDavid Howells2-2/+60
Disallow opening of debugfs files that might be used to muck around when the kernel is locked down as various drivers give raw access to hardware through debugfs. Given the effort of auditing all 2000 or so files and manually fixing each one as necessary, I've chosen to apply a heuristic instead. The following changes are made: (1) chmod and chown are disallowed on debugfs objects (though the root dir can be modified by mount and remount, but I'm not worried about that). (2) When the kernel is locked down, only files with the following criteria are permitted to be opened: - The file must have mode 00444 - The file must not have ioctl methods - The file must not have mmap (3) When the kernel is locked down, files may only be opened for reading. Normal device interaction should be done through configfs, sysfs or a miscdev, not debugfs. Note that this makes it unnecessary to specifically lock down show_dsts(), show_devs() and show_call() in the asus-wmi driver. I would actually prefer to lock down all files by default and have the the files unlocked by the creator. This is tricky to manage correctly, though, as there are 19 creation functions and ~1600 call sites (some of them in loops scanning tables). Signed-off-by: David Howells <dhowells@redhat.com> cc: Andy Shevchenko <andy.shevchenko@gmail.com> cc: acpi4asus-user@lists.sourceforge.net cc: platform-driver-x86@vger.kernel.org cc: Matthew Garrett <mjg59@srcf.ucam.org> cc: Thomas Gleixner <tglx@linutronix.de> Cc: Greg KH <greg@kroah.com> Cc: Rafael J. Wysocki <rafael@kernel.org> Signed-off-by: Matthew Garrett <matthewgarrett@google.com> Signed-off-by: James Morris <jmorris@namei.org>
2019-07-12Merge tag 'driver-core-5.3-rc1' of ↵Linus Torvalds2-16/+32
git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core Pull driver core and debugfs updates from Greg KH: "Here is the "big" driver core and debugfs changes for 5.3-rc1 It's a lot of different patches, all across the tree due to some api changes and lots of debugfs cleanups. Other than the debugfs cleanups, in this set of changes we have: - bus iteration function cleanups - scripts/get_abi.pl tool to display and parse Documentation/ABI entries in a simple way - cleanups to Documenatation/ABI/ entries to make them parse easier due to typos and other minor things - default_attrs use for some ktype users - driver model documentation file conversions to .rst - compressed firmware file loading - deferred probe fixes All of these have been in linux-next for a while, with a bunch of merge issues that Stephen has been patient with me for" * tag 'driver-core-5.3-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: (102 commits) debugfs: make error message a bit more verbose orangefs: fix build warning from debugfs cleanup patch ubifs: fix build warning after debugfs cleanup patch driver: core: Allow subsystems to continue deferring probe drivers: base: cacheinfo: Ensure cpu hotplug work is done before Intel RDT arch_topology: Remove error messages on out-of-memory conditions lib: notifier-error-inject: no need to check return value of debugfs_create functions swiotlb: no need to check return value of debugfs_create functions ceph: no need to check return value of debugfs_create functions sunrpc: no need to check return value of debugfs_create functions ubifs: no need to check return value of debugfs_create functions orangefs: no need to check return value of debugfs_create functions nfsd: no need to check return value of debugfs_create functions lib: 842: no need to check return value of debugfs_create functions debugfs: provide pr_fmt() macro debugfs: log errors when something goes wrong drivers: s390/cio: Fix compilation warning about const qualifiers drivers: Add generic helper to match by of_node driver_find_device: Unify the match function with class_find_device() bus_find_device: Unify the match callback with class_find_device ...
2019-07-08debugfs: make error message a bit more verboseGreg Kroah-Hartman1-1/+6
When a file/directory is already present in debugfs, and it is attempted to be created again, be more specific about what file/directory is being created and where it is trying to be created to give a bit more help to developers to figure out the problem. Cc: Stephen Rothwell <sfr@canb.auug.org.au> Cc: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Cc: Mark Brown <broonie@kernel.org> Cc: Takashi Iwai <tiwai@suse.de> Reviewed-by: Mark Brown <broonie@kernel.org> Link: https://lore.kernel.org/r/20190706154256.GA2683@kroah.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-07-03debugfs: provide pr_fmt() macroGreg Kroah-Hartman1-1/+3
Use a common "debugfs: " prefix for all pr_* calls in a single place. Cc: Mark Brown <broonie@kernel.org> Reviewed-by: Takashi Iwai <tiwai@suse.de> Reviewed-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Link: https://lore.kernel.org/r/20190703071653.2799-1-gregkh@linuxfoundation.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-07-03debugfs: log errors when something goes wrongGreg Kroah-Hartman1-5/+20
As it is not recommended that debugfs calls be checked, it was pointed out that major errors should still be logged somewhere so that developers and users have a chance to figure out what went wrong. To help with this, error logging has been added to the debugfs core so that it is not needed to be present in every individual file that calls debugfs. Reported-by: Mark Brown <broonie@kernel.org> Reported-by: Takashi Iwai <tiwai@suse.de> Reviewed-by: Mark Brown <broonie@kernel.org> Reviewed-by: Takashi Iwai <tiwai@suse.de> Reviewed-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Link: https://lore.kernel.org/r/20190703071653.2799-2-gregkh@linuxfoundation.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-06-20debugfs: call fsnotify_{unlink,rmdir}() hooksAmir Goldstein1-0/+3
This will allow generating fsnotify delete events after the fsnotify_nameremove() hook is removed from d_delete(). Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Jan Kara <jack@suse.cz>
2019-06-20debugfs: simplify __debugfs_remove_file()Amir Goldstein1-12/+8
Move simple_unlink()+d_delete() from __debugfs_remove_file() into caller __debugfs_remove() and rename helper for post remove file to __debugfs_file_removed(). This will simplify adding fsnotify_unlink() hook. Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Jan Kara <jack@suse.cz>
2019-06-03debugfs: make debugfs_create_u32_array() return voidGreg Kroah-Hartman1-10/+4
The single user of debugfs_create_u32_array() does not care about the return value of it, so make it return void as there is no need to do anything with the return value. Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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>