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* xen: Drop un-informative message during bootPunit Agrawal2017-07-271-1/+0
| | | | | | | | | | | | | | | | On systems that are not booted as a Xen domain, the xenfs driver prints the following message during boot. [ 3.460595] xenfs: not registering filesystem on non-xen platform As the user chose not to boot a Xen domain, this message does not provide useful information. Drop this message. Signed-off-by: Punit Agrawal <punit.agrawal@arm.com> Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com> Cc: Juergen Gross <jgross@suse.com> Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Signed-off-by: Juergen Gross <jgross@suse.com>
* fs: constify tree_descr arrays passed to simple_fill_super()Eric Biggers2017-04-261-2/+2
| | | | | | | | | | | | simple_fill_super() is passed an array of tree_descr structures which describe the files to create in the filesystem's root directory. Since these arrays are never modified intentionally, they should be 'const' so that they are placed in .rodata and benefit from memory protection. This patch updates the function signature and all users, and also constifies tree_descr.name. Signed-off-by: Eric Biggers <ebiggers@google.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* xen: clean up xenbus internal headersJuergen Gross2017-02-092-2/+2
| | | | | | | | | | | | | | | | The xenbus driver has an awful mixture of internally and globally visible headers: some of the internally used only stuff is defined in the global header include/xen/xenbus.h while some stuff defined in internal headers is used by other drivers, too. Clean this up by moving the externally used symbols to include/xen/xenbus.h and the symbols used internally only to a new header drivers/xen/xenbus/xenbus.h replacing xenbus_comms.h and xenbus_probe.h Signed-off-by: Juergen Gross <jgross@suse.com> Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
* xen: audit usages of module.h ; remove unnecessary instancesPaul Gortmaker2016-03-211-1/+0
| | | | | | | | | | | | | | | | | | | Code that uses no modular facilities whatsoever should not be sourcing module.h at all, since that header drags in a bunch of other headers with it. Similarly, code that is not explicitly using modular facilities like module_init() but only is declaring module_param setup variables should be using moduleparam.h and not the larger module.h file for that. In making this change, we also uncover an implicit use of BUG() in inline fcns within arch/arm/include/asm/xen/hypercall.h so we explicitly source <linux/bug.h> for that file now. Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com> Reviewed-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com> Signed-off-by: David Vrabel <david.vrabel@citrix.com>
* xen: rename dom0_op to platform_opStefano Stabellini2015-12-211-2/+2
| | | | | | | | | The dom0_op hypercall has been renamed to platform_op since Xen 3.2, which is ancient, and modern upstream Linux kernels cannot run as dom0 and it anymore anyway. Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com> Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
* xen: xensyms supportBoris Ostrovsky2015-08-204-0/+157
| | | | | | | | | Export Xen symbols to dom0 via /proc/xen/xensyms (similar to /proc/kallsyms). Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Reviewed-by: David Vrabel <david.vrabel@citrix.com> Signed-off-by: David Vrabel <david.vrabel@citrix.com>
* xen: Convert printks to pr_<level>Joe Perches2013-06-281-1/+3
| | | | | | | | | | | | | | | | | Convert printks to pr_<level> (excludes printk(KERN_DEBUG...) to be more consistent throughout the xen subsystem. Add pr_fmt with KBUILD_MODNAME or "xen:" KBUILD_MODNAME Coalesce formats and add missing word spaces Add missing newlines Align arguments and reflow to 80 columns Remove DRV_NAME from formats as pr_fmt adds the same content This does change some of the prefixes of these messages but it also does make them more consistent. Signed-off-by: Joe Perches <joe@perches.com> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
* fs: Limit sys_mount to only request filesystem modules.Eric W. Biederman2013-03-031-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Modify the request_module to prefix the file system type with "fs-" and add aliases to all of the filesystems that can be built as modules to match. A common practice is to build all of the kernel code and leave code that is not commonly needed as modules, with the result that many users are exposed to any bug anywhere in the kernel. Looking for filesystems with a fs- prefix limits the pool of possible modules that can be loaded by mount to just filesystems trivially making things safer with no real cost. Using aliases means user space can control the policy of which filesystem modules are auto-loaded by editing /etc/modprobe.d/*.conf with blacklist and alias directives. Allowing simple, safe, well understood work-arounds to known problematic software. This also addresses a rare but unfortunate problem where the filesystem name is not the same as it's module name and module auto-loading would not work. While writing this patch I saw a handful of such cases. The most significant being autofs that lives in the module autofs4. This is relevant to user namespaces because we can reach the request module in get_fs_type() without having any special permissions, and people get uncomfortable when a user specified string (in this case the filesystem type) goes all of the way to request_module. After having looked at this issue I don't think there is any particular reason to perform any filtering or permission checks beyond making it clear in the module request that we want a filesystem module. The common pattern in the kernel is to call request_module() without regards to the users permissions. In general all a filesystem module does once loaded is call register_filesystem() and go to sleep. Which means there is not much attack surface exposed by loading a filesytem module unless the filesystem is mounted. In a user namespace filesystems are not mounted unless .fs_flags = FS_USERNS_MOUNT, which most filesystems do not set today. Acked-by: Serge Hallyn <serge.hallyn@canonical.com> Acked-by: Kees Cook <keescook@chromium.org> Reported-by: Kees Cook <keescook@google.com> Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
* xenfs: switch to pure simple_fill_super()Al Viro2013-02-221-55/+11
| | | | Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* userns: Convert xenfs to use kuid and kgid where appropriateEric W. Biederman2012-09-211-1/+2
| | | | | | | Cc: Ian Campbell <ian.campbell@citrix.com> Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Acked-by: Serge Hallyn <serge.hallyn@canonical.com> Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
* xen: Add xenbus device driverBastian Blank2011-12-164-596/+3
| | | | | | | | | Access to xenbus is currently handled via xenfs. This adds a device driver for xenbus and makes xenfs use this code. Signed-off-by: Bastian Blank <waldi@debian.org> Acked-by: Ian Campbell <ian.campbell@citrix.com> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
* xen: Add privcmd device driverBastian Blank2011-12-164-403/+3
| | | | | | | | | | Access to arbitrary hypercalls is currently provided via xenfs. This adds a standard character device to handle this. The support in xenfs remains for backward compatibility and uses the device driver code. Signed-off-by: Bastian Blank <waldi@debian.org> Acked-by: Ian Campbell <ian.campbell@citrix.com> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
* Merge branch 'xen/xenbus' of ↵Linus Torvalds2011-01-201-18/+13
|\ | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/jeremy/xen * 'xen/xenbus' of git://git.kernel.org/pub/scm/linux/kernel/git/jeremy/xen: xenbus: Fix memory leak on release xenbus: avoid zero returns from read() xenbus: add missing wakeup in concurrent read/write xenbus: allow any xenbus command over /proc/xen/xenbus xenfs/xenbus: report partial reads/writes correctly
| * xenbus: Fix memory leak on releaseDaniel De Graaf2010-12-201-0/+5
| | | | | | | | | | | | | | | | Pending responses were leaked on close. Signed-off-by: Daniel De Graaf <dgdegra@tycho.nsa.gov> Signed-off-by: Jan Beulich <jbeulich@novell.com> Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
| * xenbus: avoid zero returns from read()Daniel De Graaf2010-09-091-0/+3
| | | | | | | | | | | | | | | | | | | | It is possible to get a zero return from read() in instances where the queue is not empty but has no elements with data to deliver to the user. Since a zero return from read is an error indicator, resume waiting or return -EAGAIN (for a nonblocking fd) in this case. Signed-off-by: Daniel De Graaf <dgdegra@tycho.nsa.gov> Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
| * xenbus: add missing wakeup in concurrent read/writeDaniel De Graaf2010-09-081-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | If an application has a dedicated read thread watching xenbus and another thread writes an XS_WATCH message that generates a synthetic "OK" reply, this reply will be enqueued in the buffer without waking up the reader. This can cause a deadlock in the application if it then waits for the read thread to receive the queued message. Signed-off-by: Daniel De Graaf <dgdegra@tycho.nsa.gov> commit e752969f502a511e83f841aa01d6cd332e6d85a0 Author: Daniel De Graaf <dgdegra@tycho.nsa.gov> Date: Tue Sep 7 11:21:52 2010 -0400 xenbus: fix deadlock in concurrent read/write If an application has a dedicated read thread watching xenbus and another thread writes an XS_WATCH message that generates a synthetic "OK" reply, this reply will be enqueued in the buffer without waking up the reader. Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
| * xenbus: allow any xenbus command over /proc/xen/xenbusDiego Ongaro2010-09-011-16/+2
| | | | | | | | | | | | | | | | | | | | | | When xenstored is in another domain, we need to be able to send any command over xenbus. This doesn't pose a security problem because its up to xenstored to determine whether a given client is allowed to use a particular command anyway. From linux-2.5.18-xen.hg 68d582b0ad05. Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
| * xenfs/xenbus: report partial reads/writes correctlyJeremy Fitzhardinge2010-08-251-2/+2
| | | | | | | | | | | | | | | | copy_(to|from)_user return the number of uncopied bytes, so a successful return is 0, and any non-zero result indicates some degree of failure. Reported-by: "Jun Zhu (Intern)" <Jun.Zhu@citrix.com> Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
* | Merge branch 'upstream/for-linus' of ↵Linus Torvalds2010-11-242-47/+12
|\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/jeremy/xen * 'upstream/for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jeremy/xen: (23 commits) xen/events: Use PIRQ instead of GSI value when unmapping MSI/MSI-X irqs. xen: set IO permission early (before early_cpu_init()) xen: re-enable boot-time ballooning xen/balloon: make sure we only include remaining extra ram xen/balloon: the balloon_lock is useless xen: add extra pages to balloon xen: make evtchn's name less generic xen/evtchn: the evtchn device is non-seekable Revert "xen/privcmd: create address space to allow writable mmaps" xen/events: use locked set|clear_bit() for cpu_evtchn_mask xen/evtchn: clear secondary CPUs' cpu_evtchn_mask[] after restore xen/xenfs: update xenfs_mount for new prototype xen: fix header export to userspace xen: implement XENMEM_machphys_mapping xen: set vma flag VM_PFNMAP in the privcmd mmap file_op xen: xenfs: privcmd: check put_user() return code xen/evtchn: add missing static xen/evtchn: Fix name of Xen event-channel device xen/evtchn: don't do unbind_from_irqhandler under spinlock xen/evtchn: remove spurious barrier ...
| * | Revert "xen/privcmd: create address space to allow writable mmaps"Jeremy Fitzhardinge2010-11-181-36/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This reverts commit 24a89b5be4cf2b7f1b49b56b6cb4a7b71fccf241. We should no longer need an address space now that we're correctly setting VM_PFNMAP on our vmas. Conflicts: drivers/xen/xenfs/super.c Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
| * | xen/xenfs: update xenfs_mount for new prototypeJeremy Fitzhardinge2010-11-161-3/+3
| | | | | | | | | | | | | | | | | | .mount now returns a struct dentry *. Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
| * | Merge commit 'v2.6.37-rc2' into upstream/xenfsJeremy Fitzhardinge2010-11-162-4/+6
| |\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | * commit 'v2.6.37-rc2': (10093 commits) Linux 2.6.37-rc2 capabilities/syslog: open code cap_syslog logic to fix build failure i2c: Sanity checks on adapter registration i2c: Mark i2c_adapter.id as deprecated i2c: Drivers shouldn't include <linux/i2c-id.h> i2c: Delete unused adapter IDs i2c: Remove obsolete cleanup for clientdata include/linux/kernel.h: Move logging bits to include/linux/printk.h Fix gcc 4.5.1 miscompiling drivers/char/i8k.c (again) hwmon: (w83795) Check for BEEP pin availability hwmon: (w83795) Clear intrusion alarm immediately hwmon: (w83795) Read the intrusion state properly hwmon: (w83795) Print the actual temperature channels as sources hwmon: (w83795) List all usable temperature sources hwmon: (w83795) Expose fan control method hwmon: (w83795) Fix fan control mode attributes hwmon: (lm95241) Check validity of input values hwmon: Change mail address of Hans J. Koch PCI: sysfs: fix printk warnings GFS2: Fix inode deallocation race ...
| * | | xen: set vma flag VM_PFNMAP in the privcmd mmap file_opStefano Stabellini2010-11-111-2/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Set VM_PFNMAP in the privcmd mmap file_op, rather than later in xen_remap_domain_mfn_range when it is too late because vma_wants_writenotify has already been called and vm_page_prot has already been modified. Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com> Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
| * | | xen: xenfs: privcmd: check put_user() return codeVasiliy Kulikov2010-10-291-6/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | put_user() may fail. In this case propagate error code from privcmd_ioctl_mmap_batch(). Signed-off-by: Vasiliy Kulikov <segooon@gmail.com> Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
* | | | BKL: remove extraneous #include <smp_lock.h>Arnd Bergmann2010-11-171-1/+0
| |/ / |/| | | | | | | | | | | | | | | | | | | | | | | | | | The big kernel lock has been removed from all these files at some point, leaving only the #include. Remove this too as a cleanup. Signed-off-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | | convert get_sb_single() usersAl Viro2010-10-291-4/+4
| | | | | | | | | | | | Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
| | |
| \ \
*-. \ \ Merge branches 'upstream/xenfs' and 'upstream/core' of ↵Linus Torvalds2010-10-265-6/+567
|\ \ \ \ | | |/ / | |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/jeremy/xen * 'upstream/xenfs' of git://git.kernel.org/pub/scm/linux/kernel/git/jeremy/xen: xen/privcmd: make privcmd visible in domU xen/privcmd: move remap_domain_mfn_range() to core xen code and export. privcmd: MMAPBATCH: Fix error handling/reporting xenbus: export xen_store_interface for xenfs xen/privcmd: make sure vma is ours before doing anything to it xen/privcmd: print SIGBUS faults xen/xenfs: set_page_dirty is supposed to return true if it dirties xen/privcmd: create address space to allow writable mmaps xen: add privcmd driver xen: add variable hypercall caller xen: add xen_set_domain_pte() xen: add /proc/xen/xsd_{kva,port} to xenfs * 'upstream/core' of git://git.kernel.org/pub/scm/linux/kernel/git/jeremy/xen: (29 commits) xen: include xen/xen.h for definition of xen_initial_domain() xen: use host E820 map for dom0 xen: correctly rebuild mfn list list after migration. xen: improvements to VIRQ_DEBUG output xen: set up IRQ before binding virq to evtchn xen: ensure that all event channels start off bound to VCPU 0 xen/hvc: only notify if we actually sent something xen: don't add extra_pages for RAM after mem_end xen: add support for PAT xen: make sure xen_max_p2m_pfn is up to date xen: limit extra memory to a certain ratio of base xen: add extra pages for E820 RAM regions, even if beyond mem_end xen: make sure xen_extra_mem_start is beyond all non-RAM e820 xen: implement "extra" memory to reserve space for pages not present at boot xen: Use host-provided E820 map xen: don't map missing memory xen: defer building p2m mfn structures until kernel is mapped xen: add return value to set_phys_to_machine() xen: convert p2m to a 3 level tree xen: make install_p2mtop_page() static ... Fix up trivial conflict in arch/x86/xen/mmu.c, and fix the use of 'reserve_early()' - in the new memblock world order it is now 'memblock_x86_reserve_range()' instead. Pointed out by Jeremy.
| * | | xen/privcmd: make privcmd visible in domUJeremy Fitzhardinge2010-10-202-4/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | It has its uses in a domU as well as dom0. Xen will prevent an unprivileged domain from doing anything untoward. Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
| * | | xen/privcmd: move remap_domain_mfn_range() to core xen code and export.Ian Campbell2010-10-201-73/+8
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This allows xenfs to be built as a module, previously it required flush_tlb_all and arbitrary_virt_to_machine to be exported. Signed-off-by: Ian Campbell <ian.campbell@citrix.com> Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
| * | | privcmd: MMAPBATCH: Fix error handling/reportingIan Campbell2010-10-201-15/+41
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | On error IOCTL_PRIVCMD_MMAPBATCH is expected to set the top nibble of the effected MFN and return 0. Currently it leaves the MFN unmodified and returns the number of failures. Therefore: - reimplement remap_domain_mfn_range() using direct HYPERVISOR_mmu_update() calls and small batches. The xen_set_domain_pte() interface does not report errors and since some failures are expected/normal using the multicall infrastructure is too noisy. - return 0 as expected - writeback the updated MFN list to mmapbatch->arr not over mmapbatch, smashing the caller's stack. - remap_domain_mfn_range can be static. With this change I am able to start an HVM domain. Signed-off-by: Ian Campbell <ian.campbell@citrix.com> Cc: Jeremy Fitzhardinge <jeremy@goop.org> Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
| * | | xen/privcmd: make sure vma is ours before doing anything to itJeremy Fitzhardinge2010-10-201-0/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Test vma->vm_ops is our operations to make sure we created it. We don't want to stomp on other random vmas. [ Impact: bugfix; prevent ioctl from affecting other mappings ] Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
| * | | xen/privcmd: print SIGBUS faultsJeremy Fitzhardinge2010-10-201-0/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Print more detail about privcmd mapping faults for debugging. [ Impact: debug ] Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
| * | | xen/xenfs: set_page_dirty is supposed to return true if it dirtiesJeremy Fitzhardinge2010-10-201-3/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | I don't think it matters at all in this case (there's only one caller which checks the return value), but may as well be strictly correct. [ Impact: cleanup ] Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
| * | | xen/privcmd: create address space to allow writable mmapsJeremy Fitzhardinge2010-10-201-4/+38
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | These are necessary to allow writeable mmap of the privcmd node to succeed without being marked read-only for writenotify purposes. Which in turn is necessary to allow mappings of foreign guest pages [ Impact: bugfix: allow writable mappings ] Signed-off-by: Ian Campbell <ian.campbell@citrix.com> Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
| * | | xen: add privcmd driverJeremy Fitzhardinge2010-10-204-1/+440
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The privcmd interface in xenfs allows the tool stack in the privileged domain to get fairly direct access to the hypervisor in order to do various management things such as domain construction. [ Impact: new xenfs interface for privileged operations ] Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
| * | | xen: add /proc/xen/xsd_{kva,port} to xenfsIan Campbell2010-10-204-2/+125
| |/ / | | | | | | | | | | | | | | | | | | | | | | | | | | | These are used by the userspace xenstore daemon, which runs in dom0. Xenstored is what's behind the xenfs "xenbus" filesystem. [ Impact: provide mapping and port to usermode for xenstore ] Signed-off-by: Ian Campbell <ian.campbell@citrix.com> Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
* | | llseek: automatically add .llseek fopArnd Bergmann2010-10-152-0/+2
|/ / | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | All file_operations should get a .llseek operation so we can make nonseekable_open the default for future file operations without a .llseek pointer. The three cases that we can automatically detect are no_llseek, seq_lseek and default_llseek. For cases where we can we can automatically prove that the file offset is always ignored, we use noop_llseek, which maintains the current behavior of not returning an error from a seek. New drivers should normally not use noop_llseek but instead use no_llseek and call nonseekable_open at open time. Existing drivers can be converted to do the same when the maintainer knows for certain that no user code relies on calling seek on the device file. The generated code is often incorrectly indented and right now contains comments that clarify for each added line why a specific variant was chosen. In the version that gets submitted upstream, the comments will be gone and I will manually fix the indentation, because there does not seem to be a way to do that using coccinelle. Some amount of new code is currently sitting in linux-next that should get the same modifications, which I will do at the end of the merge window. Many thanks to Julia Lawall for helping me learn to write a semantic patch that does all this. ===== begin semantic patch ===== // This adds an llseek= method to all file operations, // as a preparation for making no_llseek the default. // // The rules are // - use no_llseek explicitly if we do nonseekable_open // - use seq_lseek for sequential files // - use default_llseek if we know we access f_pos // - use noop_llseek if we know we don't access f_pos, // but we still want to allow users to call lseek // @ open1 exists @ identifier nested_open; @@ nested_open(...) { <+... nonseekable_open(...) ...+> } @ open exists@ identifier open_f; identifier i, f; identifier open1.nested_open; @@ int open_f(struct inode *i, struct file *f) { <+... ( nonseekable_open(...) | nested_open(...) ) ...+> } @ read disable optional_qualifier exists @ identifier read_f; identifier f, p, s, off; type ssize_t, size_t, loff_t; expression E; identifier func; @@ ssize_t read_f(struct file *f, char *p, size_t s, loff_t *off) { <+... ( *off = E | *off += E | func(..., off, ...) | E = *off ) ...+> } @ read_no_fpos disable optional_qualifier exists @ identifier read_f; identifier f, p, s, off; type ssize_t, size_t, loff_t; @@ ssize_t read_f(struct file *f, char *p, size_t s, loff_t *off) { ... when != off } @ write @ identifier write_f; identifier f, p, s, off; type ssize_t, size_t, loff_t; expression E; identifier func; @@ ssize_t write_f(struct file *f, const char *p, size_t s, loff_t *off) { <+... ( *off = E | *off += E | func(..., off, ...) | E = *off ) ...+> } @ write_no_fpos @ identifier write_f; identifier f, p, s, off; type ssize_t, size_t, loff_t; @@ ssize_t write_f(struct file *f, const char *p, size_t s, loff_t *off) { ... when != off } @ fops0 @ identifier fops; @@ struct file_operations fops = { ... }; @ has_llseek depends on fops0 @ identifier fops0.fops; identifier llseek_f; @@ struct file_operations fops = { ... .llseek = llseek_f, ... }; @ has_read depends on fops0 @ identifier fops0.fops; identifier read_f; @@ struct file_operations fops = { ... .read = read_f, ... }; @ has_write depends on fops0 @ identifier fops0.fops; identifier write_f; @@ struct file_operations fops = { ... .write = write_f, ... }; @ has_open depends on fops0 @ identifier fops0.fops; identifier open_f; @@ struct file_operations fops = { ... .open = open_f, ... }; // use no_llseek if we call nonseekable_open //////////////////////////////////////////// @ nonseekable1 depends on !has_llseek && has_open @ identifier fops0.fops; identifier nso ~= "nonseekable_open"; @@ struct file_operations fops = { ... .open = nso, ... +.llseek = no_llseek, /* nonseekable */ }; @ nonseekable2 depends on !has_llseek @ identifier fops0.fops; identifier open.open_f; @@ struct file_operations fops = { ... .open = open_f, ... +.llseek = no_llseek, /* open uses nonseekable */ }; // use seq_lseek for sequential files ///////////////////////////////////// @ seq depends on !has_llseek @ identifier fops0.fops; identifier sr ~= "seq_read"; @@ struct file_operations fops = { ... .read = sr, ... +.llseek = seq_lseek, /* we have seq_read */ }; // use default_llseek if there is a readdir /////////////////////////////////////////// @ fops1 depends on !has_llseek && !nonseekable1 && !nonseekable2 && !seq @ identifier fops0.fops; identifier readdir_e; @@ // any other fop is used that changes pos struct file_operations fops = { ... .readdir = readdir_e, ... +.llseek = default_llseek, /* readdir is present */ }; // use default_llseek if at least one of read/write touches f_pos ///////////////////////////////////////////////////////////////// @ fops2 depends on !fops1 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @ identifier fops0.fops; identifier read.read_f; @@ // read fops use offset struct file_operations fops = { ... .read = read_f, ... +.llseek = default_llseek, /* read accesses f_pos */ }; @ fops3 depends on !fops1 && !fops2 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @ identifier fops0.fops; identifier write.write_f; @@ // write fops use offset struct file_operations fops = { ... .write = write_f, ... + .llseek = default_llseek, /* write accesses f_pos */ }; // Use noop_llseek if neither read nor write accesses f_pos /////////////////////////////////////////////////////////// @ fops4 depends on !fops1 && !fops2 && !fops3 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @ identifier fops0.fops; identifier read_no_fpos.read_f; identifier write_no_fpos.write_f; @@ // write fops use offset struct file_operations fops = { ... .write = write_f, .read = read_f, ... +.llseek = noop_llseek, /* read and write both use no f_pos */ }; @ depends on has_write && !has_read && !fops1 && !fops2 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @ identifier fops0.fops; identifier write_no_fpos.write_f; @@ struct file_operations fops = { ... .write = write_f, ... +.llseek = noop_llseek, /* write uses no f_pos */ }; @ depends on has_read && !has_write && !fops1 && !fops2 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @ identifier fops0.fops; identifier read_no_fpos.read_f; @@ struct file_operations fops = { ... .read = read_f, ... +.llseek = noop_llseek, /* read uses no f_pos */ }; @ depends on !has_read && !has_write && !fops1 && !fops2 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @ identifier fops0.fops; @@ struct file_operations fops = { ... +.llseek = noop_llseek, /* no read or write fn */ }; ===== End semantic patch ===== Signed-off-by: Arnd Bergmann <arnd@arndb.de> Cc: Julia Lawall <julia@diku.dk> Cc: Christoph Hellwig <hch@infradead.org>
* | Merge branch 'xen/xenbus' into upstream/xenJeremy Fitzhardinge2010-08-041-0/+3
|\ \ | |/ | | | | | | | | * xen/xenbus: implement O_NONBLOCK for /proc/xen/xenbus xenbus: do not hold transaction_mutex when returning to userspace
| * implement O_NONBLOCK for /proc/xen/xenbusPaolo Bonzini2010-07-261-0/+3
| | | | | | | | | | | | | | | | This patch implements O_NONBLOCK for /proc/xen/xenbus. It is a simple matter of returning -EAGAIN instead of waiting on a queue. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
* | xenfs: enable for HVM domains tooJeremy Fitzhardinge2010-07-261-2/+2
| | | | | | | | Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
* | include cleanup: Update gfp.h and slab.h includes to prepare for breaking ↵Tejun Heo2010-03-301-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | implicit slab.h inclusion from percpu.h percpu.h is included by sched.h and module.h and thus ends up being included when building most .c files. percpu.h includes slab.h which in turn includes gfp.h making everything defined by the two files universally available and complicating inclusion dependencies. percpu.h -> slab.h dependency is about to be removed. Prepare for this change by updating users of gfp and slab facilities include those headers directly instead of assuming availability. As this conversion needs to touch large number of source files, the following script is used as the basis of conversion. http://userweb.kernel.org/~tj/misc/slabh-sweep.py The script does the followings. * Scan files for gfp and slab usages and update includes such that only the necessary includes are there. ie. if only gfp is used, gfp.h, if slab is used, slab.h. * When the script inserts a new include, it looks at the include blocks and try to put the new include such that its order conforms to its surrounding. It's put in the include block which contains core kernel includes, in the same order that the rest are ordered - alphabetical, Christmas tree, rev-Xmas-tree or at the end if there doesn't seem to be any matching order. * If the script can't find a place to put a new include (mostly because the file doesn't have fitting include block), it prints out an error message indicating which .h file needs to be added to the file. The conversion was done in the following steps. 1. The initial automatic conversion of all .c files updated slightly over 4000 files, deleting around 700 includes and adding ~480 gfp.h and ~3000 slab.h inclusions. The script emitted errors for ~400 files. 2. Each error was manually checked. Some didn't need the inclusion, some needed manual addition while adding it to implementation .h or embedding .c file was more appropriate for others. This step added inclusions to around 150 files. 3. The script was run again and the output was compared to the edits from #2 to make sure no file was left behind. 4. Several build tests were done and a couple of problems were fixed. e.g. lib/decompress_*.c used malloc/free() wrappers around slab APIs requiring slab.h to be added manually. 5. The script was run on all .h files but without automatically editing them as sprinkling gfp.h and slab.h inclusions around .h files could easily lead to inclusion dependency hell. Most gfp.h inclusion directives were ignored as stuff from gfp.h was usually wildly available and often used in preprocessor macros. Each slab.h inclusion directive was examined and added manually as necessary. 6. percpu.h was updated not to include slab.h. 7. Build test were done on the following configurations and failures were fixed. CONFIG_GCOV_KERNEL was turned off for all tests (as my distributed build env didn't work with gcov compiles) and a few more options had to be turned off depending on archs to make things build (like ipr on powerpc/64 which failed due to missing writeq). * x86 and x86_64 UP and SMP allmodconfig and a custom test config. * powerpc and powerpc64 SMP allmodconfig * sparc and sparc64 SMP allmodconfig * ia64 SMP allmodconfig * s390 SMP allmodconfig * alpha SMP allmodconfig * um on x86_64 SMP allmodconfig 8. percpu.h modifications were reverted so that it could be applied as a separate patch and serve as bisection point. Given the fact that I had only a couple of failures from tests on step 6, I'm fairly confident about the coverage of this conversion patch. If there is a breakage, it's likely to be something in one of the arch headers which should be easily discoverable easily on most builds of the specific arch. Signed-off-by: Tejun Heo <tj@kernel.org> Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
* | xen: move Xen-testing predicates to common headerJeremy Fitzhardinge2009-11-041-0/+2
| | | | | | | | | | | | | | | | Move xen_domain and related tests out of asm-x86 to xen/xen.h so they can be included whenever they are necessary. Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com> Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
* | headers: remove sched.h from poll.hAlexey Dobriyan2009-10-041-0/+1
|/ | | | | Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* xen: add "capabilities" fileJeremy Fitzhardinge2009-03-301-1/+18
| | | | | | | | The xenfs capabilities file allows usermode to determine what capabilities the domain has. The only one at present is "control_d" in a privileged domain. Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
* xen: unitialised return value in xenbus_write_transactionIan Campbell2009-01-261-6/+5
| | | | | | | | The return value of xenbus_write_transaction can be uninitialised in the success case leading to the userspace xenstore utilities failing. Signed-off-by: Ian Campbell <ian.campbell@citrix.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* xen: add xenfs to allow usermode <-> Xen interactionAlex Zeffertt2009-01-084-0/+666
The xenfs filesystem exports various interfaces to usermode. Initially this exports a file to allow usermode to interact with xenbus/xenstore. Traditionally this appeared in /proc/xen. Rather than extending procfs, this patch adds a backward-compat mountpoint on /proc/xen, and provides a xenfs filesystem which can be mounted there. Signed-off-by: Alex Zeffertt <alex.zeffertt@eu.citrix.com> Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com> Cc: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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