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* Merge branch 'work.mount' of ↵Linus Torvalds2019-03-161-3/+5
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull vfs mount infrastructure fix from Al Viro: "Fixup for sysfs braino. Capabilities checks for sysfs mount do include those on netns, but only if CONFIG_NET_NS is enabled. Sorry, should've caught that earlier..." * 'work.mount' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: fix sysfs_init_fs_context() in !CONFIG_NET_NS case
| * fix sysfs_init_fs_context() in !CONFIG_NET_NS caseAl Viro2019-03-161-3/+5
| | | | | | | | | | | | | | | | | | Permission checks on current's netns should be done only when netns are enabled. Reported-by: Dominik Brodowski <linux@dominikbrodowski.net> Fixes: 23bf1b6be9c2 Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* | Merge branch 'work.mount' of ↵Linus Torvalds2019-03-121-19/+54
|\| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull vfs mount infrastructure updates from Al Viro: "The rest of core infrastructure; no new syscalls in that pile, but the old parts are switched to new infrastructure. At that point conversions of individual filesystems can happen independently; some are done here (afs, cgroup, procfs, etc.), there's also a large series outside of that pile dealing with NFS (quite a bit of option-parsing stuff is getting used there - it's one of the most convoluted filesystems in terms of mount-related logics), but NFS bits are the next cycle fodder. It got seriously simplified since the last cycle; documentation is probably the weakest bit at the moment - I considered dropping the commit introducing Documentation/filesystems/mount_api.txt (cutting the size increase by quarter ;-), but decided that it would be better to fix it up after -rc1 instead. That pile allows to do followup work in independent branches, which should make life much easier for the next cycle. fs/super.c size increase is unpleasant; there's a followup series that allows to shrink it considerably, but I decided to leave that until the next cycle" * 'work.mount' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (41 commits) afs: Use fs_context to pass parameters over automount afs: Add fs_context support vfs: Add some logging to the core users of the fs_context log vfs: Implement logging through fs_context vfs: Provide documentation for new mount API vfs: Remove kern_mount_data() hugetlbfs: Convert to fs_context cpuset: Use fs_context kernfs, sysfs, cgroup, intel_rdt: Support fs_context cgroup: store a reference to cgroup_ns into cgroup_fs_context cgroup1_get_tree(): separate "get cgroup_root to use" into a separate helper cgroup_do_mount(): massage calling conventions cgroup: stash cgroup_root reference into cgroup_fs_context cgroup2: switch to option-by-option parsing cgroup1: switch to option-by-option parsing cgroup: take options parsing into ->parse_monolithic() cgroup: fold cgroup1_mount() into cgroup1_get_tree() cgroup: start switching to fs_context ipc: Convert mqueue fs to fs_context proc: Add fs_context support to procfs ...
| * kernfs, sysfs, cgroup, intel_rdt: Support fs_contextDavid Howells2019-02-281-19/+54
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Make kernfs support superblock creation/mount/remount with fs_context. This requires that sysfs, cgroup and intel_rdt, which are built on kernfs, be made to support fs_context also. Notes: (1) A kernfs_fs_context struct is created to wrap fs_context and the kernfs mount parameters are moved in here (or are in fs_context). (2) kernfs_mount{,_ns}() are made into kernfs_get_tree(). The extra namespace tag parameter is passed in the context if desired (3) kernfs_free_fs_context() is provided as a destructor for the kernfs_fs_context struct, but for the moment it does nothing except get called in the right places. (4) sysfs doesn't wrap kernfs_fs_context since it has no parameters to pass, but possibly this should be done anyway in case someone wants to add a parameter in future. (5) A cgroup_fs_context struct is created to wrap kernfs_fs_context and the cgroup v1 and v2 mount parameters are all moved there. (6) cgroup1 parameter parsing error messages are now handled by invalf(), which allows userspace to collect them directly. (7) cgroup1 parameter cleanup is now done in the context destructor rather than in the mount/get_tree and remount functions. Weirdies: (*) cgroup_do_get_tree() calls cset_cgroup_from_root() with locks held, but then uses the resulting pointer after dropping the locks. I'm told this is okay and needs commenting. (*) The cgroup refcount web. This really needs documenting. (*) cgroup2 only has one root? Add a suggestion from Thomas Gleixner in which the RDT enablement code is placed into its own function. [folded a leak fix from Andrey Vagin] Signed-off-by: David Howells <dhowells@redhat.com> cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> cc: Tejun Heo <tj@kernel.org> cc: Li Zefan <lizefan@huawei.com> cc: Johannes Weiner <hannes@cmpxchg.org> cc: cgroups@vger.kernel.org cc: fenghua.yu@intel.com Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* | sysfs: remove unused include of kernfs-internal.hOndrej Mosnacek2019-02-081-1/+0
| | | | | | | | | | | | | | | | | | | | This include is not needed (fs/sysfs/file.c builds just fine without it). Remove it. Cc: Tejun Heo <tj@kernel.org> Signed-off-by: Ondrej Mosnacek <omosnace@redhat.com> Reviewed-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* | sysfs: fix blank line coding style warningStephen Martin2019-01-181-0/+1
|/ | | | | | | Fixed a coding style issue. Signed-off-by: Stephen Martin <lockwood@opperline.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* sysfs: convert BUG_ON to WARN_ONGreg Kroah-Hartman2019-01-074-5/+10
| | | | | | | | | | | | | It's rude to crash the system just because the developer did something wrong, as it prevents them from usually even seeing what went wrong. So convert the few BUG_ON() calls that have snuck into the sysfs code over the years to WARN_ON() to make it more "friendly". All of these are able to be recovered from, so it makes no sense to crash. Reported-by: Linus Torvalds <torvalds@linux-foundation.org> Reviewed-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* sysfs: constify sysfs create/remove files harderJani Nikula2018-12-031-2/+2
| | | | | | | | | | | | Let the passed in array be const (and thus placed in rodata) instead of a mutable array of const pointers. Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: "Rafael J. Wysocki" <rafael@kernel.org> Reviewed-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Jani Nikula <jani.nikula@intel.com> Link: https://patchwork.freedesktop.org/patch/msgid/20181004143750.30880-1-jani.nikula@intel.com
* Merge tag 'driver-core-4.19-rc1' of ↵Linus Torvalds2018-08-181-8/+22
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core Pull driver core updates from Greg KH: "Here are all of the driver core and related patches for 4.19-rc1. Nothing huge here, just a number of small cleanups and the ability to now stop the deferred probing after init happens. All of these have been in linux-next for a while with only a merge issue reported" * tag 'driver-core-4.19-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: (21 commits) base: core: Remove WARN_ON from link dependencies check drivers/base: stop new probing during shutdown drivers: core: Remove glue dirs from sysfs earlier driver core: remove unnecessary function extern declare sysfs.h: fix non-kernel-doc comment PM / Domains: Stop deferring probe at the end of initcall iommu: Remove IOMMU_OF_DECLARE iommu: Stop deferring probe at end of initcalls pinctrl: Support stopping deferred probe after initcalls dt-bindings: pinctrl: add a 'pinctrl-use-default' property driver core: allow stopping deferred probe after init driver core: add a debugfs entry to show deferred devices sysfs: Fix internal_create_group() for named group updates base: fix order of OF initialization linux/device.h: fix kernel-doc notation warning Documentation: update firmware loader fallback reference kobject: Replace strncpy with memcpy drivers: base: cacheinfo: use OF property_read_u32 instead of get_property,read_number kernfs: Replace strncpy with memcpy device: Add #define dev_fmt similar to #define pr_fmt ...
| * sysfs: Fix internal_create_group() for named group updatesRajat Jain2018-07-071-7/+22
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | There are a couple of problems with named group updates in the code today: * sysfs_update_group() will always fail for a named group, because internal_create_group() will try to create a new sysfs directory unconditionally, which will ofcourse fail with -EEXIST. * We can leak the kernfs_node for grp->name if some one tries to: - rename a group (change grp->name), or - update a named group, to an unnamed group It appears that the whole purpose of sysfs_update_group() was to allow changing the permissions or visibility of attributes and not the names. So make it clear in the comments, and allow it to update an existing named group. Signed-off-by: Rajat Jain <rajatja@google.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* | Merge tag 'scsi-misc' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsiLinus Torvalds2018-08-151-0/+44
|\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Pull SCSI updates from James Bottomley: "This is mostly updates to the usual drivers: mpt3sas, lpfc, qla2xxx, hisi_sas, smartpqi, megaraid_sas, arcmsr. In addition, with the continuing absence of Nic we have target updates for tcmu and target core (all with reviews and acks). The biggest observable change is going to be that we're (again) trying to switch to mulitqueue as the default (a user can still override the setting on the kernel command line). Other major core stuff is the removal of the remaining Microchannel drivers, an update of the internal timers and some reworks of completion and result handling" * tag 'scsi-misc' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi: (203 commits) scsi: core: use blk_mq_run_hw_queues in scsi_kick_queue scsi: ufs: remove unnecessary query(DM) UPIU trace scsi: qla2xxx: Fix issue reported by static checker for qla2x00_els_dcmd2_sp_done() scsi: aacraid: Spelling fix in comment scsi: mpt3sas: Fix calltrace observed while running IO & reset scsi: aic94xx: fix an error code in aic94xx_init() scsi: st: remove redundant pointer STbuffer scsi: qla2xxx: Update driver version to 10.00.00.08-k scsi: qla2xxx: Migrate NVME N2N handling into state machine scsi: qla2xxx: Save frame payload size from ICB scsi: qla2xxx: Fix stalled relogin scsi: qla2xxx: Fix race between switch cmd completion and timeout scsi: qla2xxx: Fix Management Server NPort handle reservation logic scsi: qla2xxx: Flush mailbox commands on chip reset scsi: qla2xxx: Fix unintended Logout scsi: qla2xxx: Fix session state stuck in Get Port DB scsi: qla2xxx: Fix redundant fc_rport registration scsi: qla2xxx: Silent erroneous message scsi: qla2xxx: Prevent sysfs access when chip is down scsi: qla2xxx: Add longer window for chip reset ...
| * | scsi: sysfs: Introduce sysfs_{un,}break_active_protection()Bart Van Assche2018-08-021-0/+44
| |/ | | | | | | | | | | | | | | | | | | | | Introduce these two functions and export them such that the next patch can add calls to these functions from the SCSI core. Signed-off-by: Bart Van Assche <bart.vanassche@wdc.com> Acked-by: Tejun Heo <tj@kernel.org> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: <stable@vger.kernel.org> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
* | sysfs: Fix regression when adding a file to an existing groupTyler Hicks2018-07-291-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | Commit 5f81880d5204 ("sysfs, kobject: allow creating kobject belonging to arbitrary users") incorrectly changed the argument passed as the parent parameter when calling sysfs_add_file_mode_ns(). This caused some sysfs attribute files to not be added correctly to certain groups. Fixes: 5f81880d5204 ("sysfs, kobject: allow creating kobject belonging to arbitrary users") Signed-off-by: Tyler Hicks <tyhicks@canonical.com> Reported-by: Heiner Kallweit <hkallweit1@gmail.com> Tested-by: Heiner Kallweit <hkallweit1@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* | sysfs, kobject: allow creating kobject belonging to arbitrary usersDmitry Torokhov2018-07-204-23/+44
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Normally kobjects and their sysfs representation belong to global root, however it is not necessarily the case for objects in separate namespaces. For example, objects in separate network namespace logically belong to the container's root and not global root. This change lays groundwork for allowing network namespace objects ownership to be transferred to container's root user by defining get_ownership() callback in ktype structure and using it in sysfs code to retrieve desired uid/gid when creating sysfs objects for given kobject. Co-Developed-by: Tyler Hicks <tyhicks@canonical.com> Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com> Signed-off-by: Tyler Hicks <tyhicks@canonical.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* | kernfs: allow creating kernfs objects with arbitrary uid/gidDmitry Torokhov2018-07-202-3/+6
|/ | | | | | | | | | | | | | | | This change allows creating kernfs files and directories with arbitrary uid/gid instead of always using GLOBAL_ROOT_UID/GID by extending kernfs_create_dir_ns() and kernfs_create_file_ns() with uid/gid arguments. The "simple" kernfs_create_file() and kernfs_create_dir() are left alone and always create objects belonging to the global root. When creating symlinks ownership (uid/gid) is taken from the target kernfs object. Co-Developed-by: Tyler Hicks <tyhicks@canonical.com> Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com> Signed-off-by: Tyler Hicks <tyhicks@canonical.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* unfuck sysfs_mount()Al Viro2018-05-211-3/+3
| | | | | | | | | | | | | new_sb is left uninitialized in case of early failures in kernfs_mount_ns(), and while IS_ERR(root) is true in all such cases, using IS_ERR(root) || !new_sb is not a solution - IS_ERR(root) is true in some cases when new_sb is true. Make sure new_sb is initialized (and matches the reality) in all cases and fix the condition for dropping kobj reference - we want it done precisely in those situations where the reference has not been transferred into a new super_block instance. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* sysfs: symlink: export sysfs_create_link_nowarn()Grygorii Strashko2018-03-191-0/+1
| | | | | | | | | | | | | The sysfs_create_link_nowarn() is going to be used in phylib framework in subsequent patch which can be built as module. Hence, export sysfs_create_link_nowarn() to avoid build errors. Cc: Florian Fainelli <f.fainelli@gmail.com> Cc: Andrew Lunn <andrew@lunn.ch> Fixes: a3995460491d ("net: phy: Relax error checking on sysfs_create_link()") Signed-off-by: Grygorii Strashko <grygorii.strashko@ti.com> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: David S. Miller <davem@davemloft.net>
* Merge branch 'for-linus' of ↵Linus Torvalds2018-02-011-3/+2
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/pmladek/printk Pull printk updates from Petr Mladek: - Add a console_msg_format command line option: The value "default" keeps the old "[time stamp] text\n" format. The value "syslog" allows to see the syslog-like "<log level>[timestamp] text" format. This feature was requested by people doing regression tests, for example, 0day robot. They want to have both filtered and full logs at hands. - Reduce the risk of softlockup: Pass the console owner in a busy loop. This is a new approach to the old problem. It was first proposed by Steven Rostedt on Kernel Summit 2017. It marks a context in which the console_lock owner calls console drivers and could not sleep. On the other side, printk() callers could detect this state and use a busy wait instead of a simple console_trylock(). Finally, the console_lock owner checks if there is a busy waiter at the end of the special context and eventually passes the console_lock to the waiter. The hand-off works surprisingly well and helps in many situations. Well, there is still a possibility of the softlockup, for example, when the flood of messages stops and the last owner still has too much to flush. There is increasing number of people having problems with printk-related softlockups. We might eventually need to get better solution. Anyway, this looks like a good start and promising direction. - Do not allow to schedule in console_unlock() called from printk(): This reverts an older controversial commit. The reschedule helped to avoid softlockups. But it also slowed down the console output. This patch is obsoleted by the new console waiter logic described above. In fact, the reschedule made the hand-off less effective. - Deprecate "%pf" and "%pF" format specifier: It was needed on ia64, ppc64 and parisc64 to dereference function descriptors and show the real function address. It is done transparently by "%ps" and "pS" format specifier now. Sergey Senozhatsky found that all the function descriptors were in a special elf section and could be easily detected. - Remove printk_symbol() API: It has been obsoleted by "%pS" format specifier, and this change helped to remove few continuous lines and a less intuitive old API. - Remove redundant memsets: Sergey removed unnecessary memset when processing printk.devkmsg command line option. * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/pmladek/printk: (27 commits) printk: drop redundant devkmsg_log_str memsets printk: Never set console_may_schedule in console_trylock() printk: Hide console waiter logic into helpers printk: Add console owner and waiter logic to load balance console writes kallsyms: remove print_symbol() function checkpatch: add pF/pf deprecation warning symbol lookup: introduce dereference_symbol_descriptor() parisc64: Add .opd based function descriptor dereference powerpc64: Add .opd based function descriptor dereference ia64: Add .opd based function descriptor dereference sections: split dereference_function_descriptor() openrisc: Fix conflicting types for _exext and _stext lib: do not use print_symbol() irq debug: do not use print_symbol() sysfs: do not use print_symbol() drivers: do not use print_symbol() x86: do not use print_symbol() unicore32: do not use print_symbol() sh: do not use print_symbol() mn10300: do not use print_symbol() ...
| * sysfs: do not use print_symbol()Sergey Senozhatsky2018-01-051-3/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | print_symbol() is a very old API that has been obsoleted by %pS format specifier in a normal printk() call. Replace print_symbol() with a direct printk("%pS") call. Link: http://lkml.kernel.org/r/20171211125025.2270-11-sergey.senozhatsky@gmail.com To: Andrew Morton <akpm@linux-foundation.org> To: Russell King <linux@armlinux.org.uk> To: Catalin Marinas <catalin.marinas@arm.com> To: Mark Salter <msalter@redhat.com> To: Tony Luck <tony.luck@intel.com> To: David Howells <dhowells@redhat.com> To: Yoshinori Sato <ysato@users.sourceforge.jp> To: Guan Xuetao <gxt@mprc.pku.edu.cn> To: Borislav Petkov <bp@alien8.de> To: Greg Kroah-Hartman <gregkh@linuxfoundation.org> To: Thomas Gleixner <tglx@linutronix.de> To: Peter Zijlstra <peterz@infradead.org> To: Vineet Gupta <vgupta@synopsys.com> To: Fengguang Wu <fengguang.wu@intel.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Petr Mladek <pmladek@suse.com> Cc: LKML <linux-kernel@vger.kernel.org> Cc: linux-arm-kernel@lists.infradead.org Cc: linux-c6x-dev@linux-c6x.org Cc: linux-ia64@vger.kernel.org Cc: linux-am33-list@redhat.com Cc: linux-sh@vger.kernel.org Cc: linux-edac@vger.kernel.org Cc: x86@kernel.org Cc: linux-snps-arc@lists.infradead.org Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> [pmladek@suse.com: updated commit message] Signed-off-by: Petr Mladek <pmladek@suse.com>
* | sysfs: remove DEBUG definesGreg Kroah-Hartman2018-01-232-3/+0
| | | | | | | | | | | | | | | | It isn't needed at all in these files, dynamic debug is the best way to enable this type of thing, if you really want it. As it is, these defines were not doing anything at all. Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* | sysfs: use SPDX identifiersGreg Kroah-Hartman2018-01-236-13/+6
| | | | | | | | | | | | | | | | Move the license "mark" of the sysfs files to be in SPDX form, instead of the custom text that it currently is in. This is in a quest to get rid of the 700+ different ways we say "GPLv2" in the kernel tree. Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* | sysfs: turn WARN() into pr_warn()Greg Kroah-Hartman2018-01-221-2/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | It's not good to crash the machine if panic_on_warn() is set just because someone made a stupid mistake of trying to create a sysfs file with the same name of an existing one. This makes the automated testing tools a lot harder to find the real bugs in the kernel. So just print a warning out and dump the stack to get the attention of the developer that they did something foolish. Then keep on trucking, as this should not be a fatal error at all. Reported-by: Dmitry Vyukov <dvyukov@google.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* | sysfs: Use PTR_ERR_OR_ZERO()Vasyl Gomonovych2017-12-181-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | Fix ptr_ret.cocci warnings: fs/sysfs/group.c:409:8-14: WARNING: PTR_ERR_OR_ZERO can be used Use PTR_ERR_OR_ZERO rather than if(IS_ERR(...)) + PTR_ERR Generated by: scripts/coccinelle/api/ptr_ret.cocci Signed-off-by: Vasyl Gomonovych <gomonovych@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* | Rename superblock flags (MS_xyz -> SB_xyz)Linus Torvalds2017-11-271-1/+1
|/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This is a pure automated search-and-replace of the internal kernel superblock flags. The s_flags are now called SB_*, with the names and the values for the moment mirroring the MS_* flags that they're equivalent to. Note how the MS_xyz flags are the ones passed to the mount system call, while the SB_xyz flags are what we then use in sb->s_flags. The script to do this was: # places to look in; re security/*: it generally should *not* be # touched (that stuff parses mount(2) arguments directly), but # there are two places where we really deal with superblock flags. FILES="drivers/mtd drivers/staging/lustre fs ipc mm \ include/linux/fs.h include/uapi/linux/bfs_fs.h \ security/apparmor/apparmorfs.c security/apparmor/include/lib.h" # the list of MS_... constants SYMS="RDONLY NOSUID NODEV NOEXEC SYNCHRONOUS REMOUNT MANDLOCK \ DIRSYNC NOATIME NODIRATIME BIND MOVE REC VERBOSE SILENT \ POSIXACL UNBINDABLE PRIVATE SLAVE SHARED RELATIME KERNMOUNT \ I_VERSION STRICTATIME LAZYTIME SUBMOUNT NOREMOTELOCK NOSEC BORN \ ACTIVE NOUSER" SED_PROG= for i in $SYMS; do SED_PROG="$SED_PROG -e s/MS_$i/SB_$i/g"; done # we want files that contain at least one of MS_..., # with fs/namespace.c and fs/pnode.c excluded. L=$(for i in $SYMS; do git grep -w -l MS_$i $FILES; done| sort|uniq|grep -v '^fs/namespace.c'|grep -v '^fs/pnode.c') for f in $L; do sed -i $f $SED_PROG; done Requested-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* sysfs: be careful of error returns from ops->show()NeilBrown2017-04-081-2/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | ops->show() can return a negative error code. Commit 65da3484d9be ("sysfs: correctly handle short reads on PREALLOC attrs.") (in v4.4) caused this to be stored in an unsigned 'size_t' variable, so errors would look like large numbers. As a result, if an error is returned, sysfs_kf_read() will return the value of 'count', typically 4096. Commit 17d0774f8068 ("sysfs: correctly handle read offset on PREALLOC attrs") (in v4.8) extended this error to use the unsigned large 'len' as a size for memmove(). Consequently, if ->show returns an error, then the first read() on the sysfs file will return 4096 and could return uninitialized memory to user-space. If the application performs a subsequent read, this will trigger a memmove() with extremely large count, and is likely to crash the machine is bizarre ways. This bug can currently only be triggered by reading from an md sysfs attribute declared with __ATTR_PREALLOC() during the brief period between when mddev_put() deletes an mddev from the ->all_mddevs list, and when mddev_delayed_delete() - which is scheduled on a workqueue - completes. Before this, an error won't be returned by the ->show() After this, the ->show() won't be called. I can reproduce it reliably only by putting delay like usleep_range(500000,700000); early in mddev_delayed_delete(). Then after creating an md device md0 run echo clear > /sys/block/md0/md/array_state; cat /sys/block/md0/md/array_state The bug can be triggered without the usleep. Fixes: 65da3484d9be ("sysfs: correctly handle short reads on PREALLOC attrs.") Fixes: 17d0774f8068 ("sysfs: correctly handle read offset on PREALLOC attrs") Cc: stable@vger.kernel.org Signed-off-by: NeilBrown <neilb@suse.com> Acked-by: Tejun Heo <tj@kernel.org> Reported-and-tested-by: Miroslav Benes <mbenes@suse.cz> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* Merge branch 'for-4.9' of ↵Linus Torvalds2016-10-141-3/+3
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup Pull cgroup updates from Tejun Heo: - tracepoints for basic cgroup management operations added - kernfs and cgroup path formatting functions updated to behave in the style of strlcpy() - non-critical bug fixes * 'for-4.9' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup: blkcg: Unlock blkcg_pol_mutex only once when cpd == NULL cgroup: fix error handling regressions in proc_cgroup_show() and cgroup_release_agent() cpuset: fix error handling regression in proc_cpuset_show() cgroup: add tracepoints for basic operations cgroup: make cgroup_path() and friends behave in the style of strlcpy() kernfs: remove kernfs_path_len() kernfs: make kernfs_path*() behave in the style of strlcpy() kernfs: add dummy implementation of kernfs_path_from_node()
| * kernfs: make kernfs_path*() behave in the style of strlcpy()Tejun Heo2016-08-101-3/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | kernfs_path*() functions always return the length of the full path but the path content is undefined if the length is larger than the provided buffer. This makes its behavior different from strlcpy() and requires error handling in all its users even when they don't care about truncation. In addition, the implementation can actully be simplified by making it behave properly in strlcpy() style. * Update kernfs_path_from_node_locked() to always fill up the buffer with path. If the buffer is not large enough, the output is truncated and terminated. * kernfs_path() no longer needs error handling. Make it a simple inline wrapper around kernfs_path_from_node(). * sysfs_warn_dup()'s use of kernfs_path() doesn't need error handling. Updated accordingly. * cgroup_path()'s use of kernfs_path() updated to retain the old behavior. Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Acked-by: Serge Hallyn <serge.hallyn@ubuntu.com>
* | sysfs print name of undiscoverable attribute groupJohannes Thumshirn2016-09-271-2/+2
| | | | | | | | | | | | | | | | Print the name of an undiscoverable attribute group and not the pointer's address. Signed-off-by: Johannes Thumshirn <jthumshirn@suse.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* | sysfs: correctly handle read offset on PREALLOC attrsKonstantin Khlebnikov2016-08-311-1/+7
|/ | | | | | | | | | | | | | | | | | Attributes declared with __ATTR_PREALLOC use sysfs_kf_read() which returns zero bytes for non-zero offset. This breaks script checkarray in mdadm tool in debian where /bin/sh is 'dash' because its builtin 'read' reads only one byte at a time. Script gets 'i' instead of 'idle' when reads current action from /sys/block/$dev/md/sync_action and as a result does nothing. This patch adds trivial implementation of partial read: generate whole string and move required part into buffer head. Signed-off-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru> Fixes: 4ef67a8c95f3 ("sysfs/kernfs: make read requests on pre-alloc files use the buffer.") Link: https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=787950 Cc: Stable <stable@vger.kernel.org> # v3.19+ Acked-by: Tejun Heo <tj@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* kernfs: The cgroup filesystem also benefits from SB_I_NOEXECEric W. Biederman2016-06-231-2/+1
| | | | | | | | | | | | | | The cgroup filesystem is in the same boat as sysfs. No one ever permits executables of any kind on the cgroup filesystem, and there is no reasonable future case to support executables in the future. Therefore move the setting of SB_I_NOEXEC which makes the code proof against future mistakes of accidentally creating executables from sysfs to kernfs itself. Making the code simpler and covering the sysfs, cgroup, and cgroup2 filesystems. Acked-by: Seth Forshee <seth.forshee@canonical.com> Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
* mnt: Refactor fs_fully_visible into mount_too_revealingEric W. Biederman2016-06-231-2/+2
| | | | | | | | | | | | | | | | | | | Replace the call of fs_fully_visible in do_new_mount from before the new superblock is allocated with a call of mount_too_revealing after the superblock is allocated. This winds up being a much better location for maintainability of the code. The first change this enables is the replacement of FS_USERNS_VISIBLE with SB_I_USERNS_VISIBLE. Moving the flag from struct filesystem_type to sb_iflags on the superblock. Unfortunately mount_too_revealing fundamentally needs to touch mnt_flags adding several MNT_LOCKED_XXX flags at the appropriate times. If the mnt_flags did not need to be touched the code could be easily moved into the filesystem specific mount code. Acked-by: Seth Forshee <seth.forshee@canonical.com> Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
* Merge tag 'chrome-platform-4.4' of ↵Linus Torvalds2015-11-131-2/+15
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/olof/chrome-platform Pull chrome platform updates from Olof Johansson: "Here's the branch of chrome platform changes for v4.4. Some have been queued up for the full 4.3 release cycle since I forgot to send them in for that round (rebased early on to deal with fixes conflicts). Most of these enable EC communication stuff -- Pixel 2015 support, enabling building for ARM64 platforms, and a few fixes for memory leaks. There's also a patch in here to allow reading/writing the verified boot context, which depends on a sysfs patch acked by Greg" * tag 'chrome-platform-4.4' of git://git.kernel.org/pub/scm/linux/kernel/git/olof/chrome-platform: platform/chrome: Fix i2c-designware adapter name platform/chrome: Support reading/writing the vboot context sysfs: Support is_visible() on binary attributes platform/chrome: cros_ec: Fix possible leak in led_rgb_store() platform/chrome: cros_ec: Fix leak in sequence_store() platform/chrome: Enable Chrome platforms on 64-bit ARM platform/chrome: cros_ec_dev - Add a platform device ID table platform/chrome: cros_ec_lpc - Add support for Google Pixel 2 platform/chrome: cros_ec_lpc - Use existing function to check EC result platform/chrome: Make depends on MFD_CROS_EC instead CROS_EC_PROTO Revert "platform/chrome: Don't make CHROME_PLATFORMS depends on X86 || ARM"
| * sysfs: Support is_visible() on binary attributesEmilio López2015-10-071-2/+15
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | According to the sysfs header file: "The returned value will replace static permissions defined in struct attribute or struct bin_attribute." but this isn't the case, as is_visible is only called on struct attribute only. This patch introduces a new is_bin_visible() function to implement the same functionality for binary attributes, and updates documentation accordingly. Note that to keep functionality and code similar to that of normal attributes, the mode is now checked as well to ensure it contains only read/write permissions or SYSFS_PREALLOC. Reviewed-by: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Emilio López <emilio.lopez@collabora.co.uk> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Olof Johansson <olof@lixom.net>
* | Merge branch 'next' of ↵Linus Torvalds2015-11-051-0/+44
|\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security Pull security subsystem update from James Morris: "This is mostly maintenance updates across the subsystem, with a notable update for TPM 2.0, and addition of Jarkko Sakkinen as a maintainer of that" * 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security: (40 commits) apparmor: clarify CRYPTO dependency selinux: Use a kmem_cache for allocation struct file_security_struct selinux: ioctl_has_perm should be static selinux: use sprintf return value selinux: use kstrdup() in security_get_bools() selinux: use kmemdup in security_sid_to_context_core() selinux: remove pointless cast in selinux_inode_setsecurity() selinux: introduce security_context_str_to_sid selinux: do not check open perm on ftruncate call selinux: change CONFIG_SECURITY_SELINUX_CHECKREQPROT_VALUE default KEYS: Merge the type-specific data with the payload data KEYS: Provide a script to extract a module signature KEYS: Provide a script to extract the sys cert list from a vmlinux file keys: Be more consistent in selection of union members used certs: add .gitignore to stop git nagging about x509_certificate_list KEYS: use kvfree() in add_key Smack: limited capability for changing process label TPM: remove unnecessary little endian conversion vTPM: support little endian guests char: Drop owner assignment from i2c_driver ...
| * | sysfs: added __compat_only_sysfs_link_entry_to_kobj()Jarkko Sakkinen2015-10-191-0/+44
| |/ | | | | | | | | | | | | | | | | | | Added a new function __compat_only_sysfs_link_group_to_kobj() that adds a symlink from attribute or group to a kobject. This needed for maintaining backwards compatibility with PPI attributes in the TPM driver. Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com> Signed-off-by: Peter Huewe <peterhuewe@gmx.de>
* / sysfs: correctly handle short reads on PREALLOC attrs.NeilBrown2015-10-041-1/+3
|/ | | | | | | | | | | | | | | attributes declared with __ATTR_PREALLOC use sysfs_kf_read() which ignores the 'count' arg. So a 1-byte read request can return more bytes than that. This is seen with the 'dash' shell when 'read' is used on some 'md' sysfs attributes. So only return the 'min' of count and the attribute length. Signed-off-by: NeilBrown <neilb@suse.com> Acked-by: Tejun Heo <tj@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* vfs: Commit to never having exectuables on proc and sysfs.Eric W. Biederman2015-07-101-0/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Today proc and sysfs do not contain any executable files. Several applications today mount proc or sysfs without noexec and nosuid and then depend on there being no exectuables files on proc or sysfs. Having any executable files show on proc or sysfs would cause a user space visible regression, and most likely security problems. Therefore commit to never allowing executables on proc and sysfs by adding a new flag to mark them as filesystems without executables and enforce that flag. Test the flag where MNT_NOEXEC is tested today, so that the only user visible effect will be that exectuables will be treated as if the execute bit is cleared. The filesystems proc and sysfs do not currently incoporate any executable files so this does not result in any user visible effects. This makes it unnecessary to vet changes to proc and sysfs tightly for adding exectuable files or changes to chattr that would modify existing files, as no matter what the individual file say they will not be treated as exectuable files by the vfs. Not having to vet changes to closely is important as without this we are only one proc_create call (or another goof up in the implementation of notify_change) from having problematic executables on proc. Those mistakes are all too easy to make and would create a situation where there are security issues or the assumptions of some program having to be broken (and cause userspace regressions). Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
* Merge branch 'for-linus' of ↵Linus Torvalds2015-07-032-4/+35
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace Pull user namespace updates from Eric Biederman: "Long ago and far away when user namespaces where young it was realized that allowing fresh mounts of proc and sysfs with only user namespace permissions could violate the basic rule that only root gets to decide if proc or sysfs should be mounted at all. Some hacks were put in place to reduce the worst of the damage could be done, and the common sense rule was adopted that fresh mounts of proc and sysfs should allow no more than bind mounts of proc and sysfs. Unfortunately that rule has not been fully enforced. There are two kinds of gaps in that enforcement. Only filesystems mounted on empty directories of proc and sysfs should be ignored but the test for empty directories was insufficient. So in my tree directories on proc, sysctl and sysfs that will always be empty are created specially. Every other technique is imperfect as an ordinary directory can have entries added even after a readdir returns and shows that the directory is empty. Special creation of directories for mount points makes the code in the kernel a smidge clearer about it's purpose. I asked container developers from the various container projects to help test this and no holes were found in the set of mount points on proc and sysfs that are created specially. This set of changes also starts enforcing the mount flags of fresh mounts of proc and sysfs are consistent with the existing mount of proc and sysfs. I expected this to be the boring part of the work but unfortunately unprivileged userspace winds up mounting fresh copies of proc and sysfs with noexec and nosuid clear when root set those flags on the previous mount of proc and sysfs. So for now only the atime, read-only and nodev attributes which userspace happens to keep consistent are enforced. Dealing with the noexec and nosuid attributes remains for another time. This set of changes also addresses an issue with how open file descriptors from /proc/<pid>/ns/* are displayed. Recently readlink of /proc/<pid>/fd has been triggering a WARN_ON that has not been meaningful since it was added (as all of the code in the kernel was converted) and is not now actively wrong. There is also a short list of issues that have not been fixed yet that I will mention briefly. It is possible to rename a directory from below to above a bind mount. At which point any directory pointers below the renamed directory can be walked up to the root directory of the filesystem. With user namespaces enabled a bind mount of the bind mount can be created allowing the user to pick a directory whose children they can rename to outside of the bind mount. This is challenging to fix and doubly so because all obvious solutions must touch code that is in the performance part of pathname resolution. As mentioned above there is also a question of how to ensure that developers by accident or with purpose do not introduce exectuable files on sysfs and proc and in doing so introduce security regressions in the current userspace that will not be immediately obvious and as such are likely to require breaking userspace in painful ways once they are recognized" * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace: vfs: Remove incorrect debugging WARN in prepend_path mnt: Update fs_fully_visible to test for permanently empty directories sysfs: Create mountpoints with sysfs_create_mount_point sysfs: Add support for permanently empty directories to serve as mount points. kernfs: Add support for always empty directories. proc: Allow creating permanently empty directories that serve as mount points sysctl: Allow creating permanently empty directories that serve as mountpoints. fs: Add helper functions for permanently empty directories. vfs: Ignore unlocked mounts in fs_fully_visible mnt: Modify fs_fully_visible to deal with locked ro nodev and atime mnt: Refactor the logic for mounting sysfs and proc in a user namespace
| * sysfs: Add support for permanently empty directories to serve as mount points.Eric W. Biederman2015-07-011-0/+34
| | | | | | | | | | | | | | | | | | | | | | | | Add two functions sysfs_create_mount_point and sysfs_remove_mount_point that hang a permanently empty directory off of a kobject or remove a permanently emptpy directory hanging from a kobject. Export these new functions so modular filesystems can use them. Cc: stable@vger.kernel.org Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
| * mnt: Refactor the logic for mounting sysfs and proc in a user namespaceEric W. Biederman2015-05-131-4/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Fresh mounts of proc and sysfs are a very special case that works very much like a bind mount. Unfortunately the current structure can not preserve the MNT_LOCK... mount flags. Therefore refactor the logic into a form that can be modified to preserve those lock bits. Add a new filesystem flag FS_USERNS_VISIBLE that requires some mount of the filesystem be fully visible in the current mount namespace, before the filesystem may be mounted. Move the logic for calling fs_fully_visible from proc and sysfs into fs/namespace.c where it has greater access to mount namespace state. Cc: stable@vger.kernel.org Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
* | fs: sysfs: don't pass count == 0 to bin file readersVladimir Zapolskiy2015-06-011-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | If count == 0 bytes are requested by a reader, sysfs_kf_bin_read() deliberately returns 0 without passing a potentially harmful value to some externally defined underlying battr->read() function. However in case of (pos == size && count) the next clause always sets count to 0 and this value is handed over to battr->read(). The change intends to make obsolete (and remove later) a redundant sanity check in battr->read(), if it is present, or add more protection to struct bin_attribute users, who does not care about input arguments. Signed-off-by: Vladimir Zapolskiy <vz@mleia.com> Acked-by: Tejun Heo <tj@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* | sysfs: disambiguate between "error code" and "failure" in commentsAntonio Ospite2015-05-241-3/+3
|/ | | | | | | | | | | | | The sentence "Returns 0 on success or error" might be misinterpreted as "the function will always returns 0", make it less ambiguous. Also, use the word "failure" as the contrary of "success". Signed-off-by: Antonio Ospite <ao2@ao2.it> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Jonathan Corbet <corbet@lwn.net> Cc: linux-doc@vger.kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* sysfs: Only accept read/write permissions for file attributesVivien Didelot2015-03-251-0/+6
| | | | | | | | | | | | | | | | For sysfs file attributes, only read and write permissions make sense. Mask provided attribute permissions accordingly and send a warning to the console if invalid permission bits are set. This patch is originally from Guenter [1] and includes the fixup explained in the thread, that is printing permissions in octal format and limiting the scope of attributes to SYSFS_PREALLOC | 0664. [1] https://lkml.org/lkml/2015/1/19/599 Signed-off-by: Vivien Didelot <vivien.didelot@savoirfairelinux.com> Reviewed-by: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* sysfs: Use only return value from is_visible for the file modeGuenter Roeck2015-03-251-3/+2
| | | | | | | | | | | | | | | | | | | | Up to now, is_visible can only be used to either remove visibility of a file entirely or to add permissions, but not to reduce permissions. This makes it impossible, for example, to use DEVICE_ATTR_RW to define file attributes and reduce permissions to read-only. This behavior is undesirable and unnecessarily complicates code which needs to reduce permissions; instead of just returning the desired permissions, it has to ensure that the permissions in the attribute variable declaration only reflect the minimal permissions ever needed. Change semantics of is_visible to only use the permissions returned from it instead of oring the returned value with the hard-coded permissions. Signed-off-by: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Vivien Didelot <vivien.didelot@savoirfairelinux.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* Merge tag 'driver-core-3.20-rc1' of ↵Linus Torvalds2015-02-151-1/+1
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core Pull driver core patches from Greg KH: "Really tiny set of patches for this kernel. Nothing major, all described in the shortlog and have been in linux-next for a while" * tag 'driver-core-3.20-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: sysfs: fix warning when creating a sysfs group without attributes firmware_loader: handle timeout via wait_for_completion_interruptible_timeout() firmware_loader: abort request if wait_for_completion is interrupted firmware: Correct function name in comment device: Change dev_<level> logging functions to return void device: Fix dev_dbg_once macro
| * sysfs: fix warning when creating a sysfs group without attributesJavi Merino2015-02-031-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | When attempting to create a gropu without attrs, the warning prints the name of the group. However, the check for name being a NULL pointer is wrong: it uses the pointer to the name when it's NULL. Fix it to use the name if present, otherwise just put an empty string. Cc: Bruno Prémont <bonbons@linux-vserver.org> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Javi Merino <javi.merino@arm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* | kernfs: remove KERNFS_STATIC_NAMETejun Heo2015-02-131-1/+1
|/ | | | | | | | | | | | | | | | | When a new kernfs node is created, KERNFS_STATIC_NAME is used to avoid making a separate copy of its name. It's currently only used for sysfs attributes whose filenames are required to stay accessible and unchanged. There are rare exceptions where these names are allocated and formatted dynamically but for the vast majority of cases they're consts in the rodata section. Now that kernfs is converted to use kstrdup_const() and kfree_const(), there's little point in keeping KERNFS_STATIC_NAME around. Remove it. Signed-off-by: Tejun Heo <tj@kernel.org> Cc: Andrzej Hajda <a.hajda@samsung.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* sysfs/kernfs: make read requests on pre-alloc files use the buffer.NeilBrown2014-11-071-4/+28
| | | | | | | | | | | | | | | | | | | | | | | To match the previous patch which used the pre-alloc buffer for writes, this patch causes reads to use the same buffer. This is not strictly necessary as the current seq_read() will allocate on first read, so user-space can trigger the required pre-alloc. But consistency is valuable. The read function is somewhat simpler than seq_read() and, for example, does not support reading from an offset into the file: reads must be at the start of the file. As seq_read() does not use the prealloc buffer, ->seq_show is incompatible with ->prealloc and caused an EINVAL return from open(). sysfs code which calls into kernfs always chooses the correct function. As the buffer is shared with writes and other reads, the mutex is extended to cover the copy_to_user. Signed-off-by: NeilBrown <neilb@suse.de> Reviewed-by: Tejun Heo <tj@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* sysfs/kernfs: allow attributes to request write buffer be pre-allocated.NeilBrown2014-11-071-7/+24
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | md/raid allows metadata management to be performed in user-space. A various times, particularly on device failure, the metadata needs to be updated before further writes can be permitted. This means that the user-space program which updates metadata much not block on writeout, and so must not allocate memory. mlockall(MCL_CURRENT|MCL_FUTURE) and pre-allocation can avoid all memory allocation issues for user-memory, but that does not help kernel memory. Several kernel objects can be pre-allocated. e.g. files opened before any writes to the array are permitted. However some kernel allocation happens in places that cannot be pre-allocated. In particular, writes to sysfs files (to tell md that it can now allow writes to the array) allocate a buffer using GFP_KERNEL. This patch allows attributes to be marked as "PREALLOC". In that case the maximal buffer is allocated when the file is opened, and then used on each write instead of allocating a new buffer. As the same buffer is now shared for all writes on the same file description, the mutex is extended to cover full use of the buffer including the copy_from_user(). The new __ATTR_PREALLOC() 'or's a new flag in to the 'mode', which is inspected by sysfs_add_file_mode_ns() to determine if the file should be marked as requiring prealloc. Despite the comment, we *do* use ->seq_show together with ->prealloc in this patch. The next patch fixes that. Signed-off-by: NeilBrown <neilb@suse.de> Reviewed-by: Tejun Heo <tj@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* fs: sysfs: return EGBIG on write if offset is larger than file sizeVladimir Zapolskiy2014-11-071-1/+1
| | | | | | | | | | | | | | | | | | According to the user expectations common utilities like dd or sh redirection operator > should work correctly over binary files from sysfs. At the moment doing excessive write can not be completed: write(1, "\0\0\0\0\0\0\0\0", 8) = 4 write(1, "\0\0\0\0", 4) = 0 write(1, "\0\0\0\0", 4) = 0 write(1, "\0\0\0\0", 4) = 0 ... Fix the problem by returning EFBIG described in man 2 write. Signed-off-by: Vladimir Zapolskiy <vladimir_zapolskiy@mentor.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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