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2021-11-18ftrace/samples: add missing Kconfig option for ftrace direct multi sampleHeiko Carstens
Currently it is not possible to build the ftrace direct multi example anymore due to broken config dependencies. Fix this by adding SAMPLE_FTRACE_DIRECT_MULTI config option. This broke when merging s390-5.16-1 due to an incorrect merge conflict resolution proposed by me. Also rename SAMPLE_FTRACE_MULTI_DIRECT to SAMPLE_FTRACE_DIRECT_MULTI so it matches the module name. Fixes: 0b707e572a19 ("Merge tag 's390-5.16-1' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux") Acked-by: Steven Rostedt (VMware) <rostedt@goodmis.org> Link: https://lore.kernel.org/r/20211115195614.3173346-2-hca@linux.ibm.com Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2021-11-06Merge tag 'fsnotify_for_v5.16-rc1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs Pull fsnotify updates from Jan Kara: "Support for reporting filesystem errors through fanotify so that system health monitoring daemons can watch for these and act instead of scraping system logs" * tag 'fsnotify_for_v5.16-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs: (34 commits) samples: remove duplicate include in fs-monitor.c samples: Fix warning in fsnotify sample docs: Fix formatting of literal sections in fanotify docs samples: Make fs-monitor depend on libc and headers docs: Document the FAN_FS_ERROR event samples: Add fs error monitoring example ext4: Send notifications on error fanotify: Allow users to request FAN_FS_ERROR events fanotify: Emit generic error info for error event fanotify: Report fid info for file related file system errors fanotify: WARN_ON against too large file handles fanotify: Add helpers to decide whether to report FID/DFID fanotify: Wrap object_fh inline space in a creator macro fanotify: Support merging of error events fanotify: Support enqueueing of error events fanotify: Pre-allocate pool of error events fanotify: Reserve UAPI bits for FAN_FS_ERROR fsnotify: Support FS_ERROR event type fanotify: Require fid_mode for any non-fd event fanotify: Encode empty file handle when no inode is provided ...
2021-11-06Merge tag 's390-5.16-1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux Pull s390 updates from Vasily Gorbik: - Add support for ftrace with direct call and ftrace direct call samples. - Add support for kernel command lines longer than current 896 bytes and make its length configurable. - Add support for BEAR enhancement facility to improve last breaking event instruction tracking. - Add kprobes sanity checks and testcases to prevent kprobe in the mid of an instruction. - Allow concurrent access to /dev/hwc for the CPUMF users. - Various ftrace / jump label improvements. - Convert unwinder tests to KUnit. - Add s390_iommu_aperture kernel parameter to tweak the limits on concurrently usable DMA mappings. - Add ap.useirq AP module option which can be used to disable interrupt use. - Add add_disk() error handling support to block device drivers. - Drop arch specific and use generic implementation of strlcpy and strrchr. - Several __pa/__va usages fixes. - Various cio, crypto, pci, kernel doc and other small fixes and improvements all over the code. [ Merge fixup as per https://lore.kernel.org/all/YXAqZ%2FEszRisunQw@osiris/ ] * tag 's390-5.16-1' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux: (63 commits) s390: make command line configurable s390: support command lines longer than 896 bytes s390/kexec_file: move kernel image size check s390/pci: add s390_iommu_aperture kernel parameter s390/spinlock: remove incorrect kernel doc indicator s390/string: use generic strlcpy s390/string: use generic strrchr s390/ap: function rework based on compiler warning s390/cio: make ccw_device_dma_* more robust s390/vfio-ap: s390/crypto: fix all kernel-doc warnings s390/hmcdrv: fix kernel doc comments s390/ap: new module option ap.useirq s390/cpumf: Allow multiple processes to access /dev/hwc s390/bitops: return true/false (not 1/0) from bool functions s390: add support for BEAR enhancement facility s390: introduce nospec_uses_trampoline() s390: rename last_break to pgm_last_break s390/ptrace: add last_break member to pt_regs s390/sclp: sort out physical vs virtual pointers usage s390/setup: convert start and end initrd pointers to virtual ...
2021-11-01samples: Make fs-monitor depend on libc and headersGabriel Krisman Bertazi
Prevent build errors when headers or libc are not available, such as on kernel build bots, like the below: samples/fanotify/fs-monitor.c:7:10: fatal error: errno.h: No such file or directory 7 | #include <errno.h> | ^~~~~~~~~ Link: https://lore.kernel.org/r/87fsslasgz.fsf@collabora.com Suggested-by: Guenter Roeck <linux@roeck-us.net> Tested-by: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Gabriel Krisman Bertazi <krisman@collabora.com> Signed-off-by: Jan Kara <jack@suse.cz>
2021-10-27samples: Add fs error monitoring exampleGabriel Krisman Bertazi
Introduce an example of a FAN_FS_ERROR fanotify user to track filesystem errors. Link: https://lore.kernel.org/r/20211025192746.66445-31-krisman@collabora.com Reviewed-by: Amir Goldstein <amir73il@gmail.com> Reviewed-by: Jan Kara <jack@suse.cz> Signed-off-by: Gabriel Krisman Bertazi <krisman@collabora.com> Signed-off-by: Jan Kara <jack@suse.cz>
2021-10-19samples: add HAVE_SAMPLE_FTRACE_DIRECT config optionHeiko Carstens
Add HAVE_SAMPLE_FTRACE_DIRECT config option which can be selected by architectures which have support for ftrace direct call samples. Acked-by: Ilya Leoshkevich <iii@linux.ibm.com> Reviewed-by: Sven Schnelle <svens@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com> Acked-by: Steven Rostedt (VMware) <rostedt@goodmis.org> Link: https://lore.kernel.org/r/20211012133802.2460757-4-hca@linux.ibm.com Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2021-06-21vfio/mdev: Remove CONFIG_VFIO_MDEV_DEVICEJason Gunthorpe
For some reason the vfio_mdev shim mdev_driver has its own module and kconfig. As the next patch requires access to it from mdev.ko merge the two modules together and remove VFIO_MDEV_DEVICE. A later patch deletes this driver entirely. Signed-off-by: Jason Gunthorpe <jgg@nvidia.com> Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Cornelia Huck <cohuck@redhat.com> Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Reviewed-by: Kirti Wankhede <kwankhede@nvidia.com> Link: https://lore.kernel.org/r/20210617142218.1877096-7-hch@lst.de Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2021-04-22samples/landlock: Add a sandbox manager exampleMickaël Salaün
Add a basic sandbox tool to launch a command which can only access a list of file hierarchies in a read-only or read-write way. Cc: James Morris <jmorris@namei.org> Cc: Serge E. Hallyn <serge@hallyn.com> Signed-off-by: Mickaël Salaün <mic@linux.microsoft.com> Reviewed-by: Jann Horn <jannh@google.com> Reviewed-by: Kees Cook <keescook@chromium.org> Link: https://lore.kernel.org/r/20210422154123.13086-12-mic@digikod.net Signed-off-by: James Morris <jamorris@linux.microsoft.com>
2021-01-21watch_queue: Drop references to /dev/watch_queueGabriel Krisman Bertazi
The merged API doesn't use a watch_queue device, but instead relies on pipes, so let the documentation reflect that. Fixes: f7e47677e39a ("watch_queue: Add a key/keyring notification facility") Signed-off-by: Gabriel Krisman Bertazi <krisman@collabora.com> Signed-off-by: David Howells <dhowells@redhat.com> Acked-by: Jarkko Sakkinen <jarkko@kernel.org> Reviewed-by: Ben Boeckel <mathstuf@gmail.com>
2020-06-22samples: watch_queue: build sample program for target architectureMasahiro Yamada
This userspace program includes UAPI headers exported to usr/include/. 'make headers' always works for the target architecture (i.e. the same architecture as the kernel), so the sample program should be built for the target as well. Kbuild now supports 'userprogs' for that. I also guarded the CONFIG option by 'depends on CC_CAN_LINK' because $(CC) may not provide libc. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2020-06-13Merge tag 'kbuild-v5.8-2' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild Pull more Kbuild updates from Masahiro Yamada: - fix build rules in binderfs sample - fix build errors when Kbuild recurses to the top Makefile - covert '---help---' in Kconfig to 'help' * tag 'kbuild-v5.8-2' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: treewide: replace '---help---' in Kconfig files with 'help' kbuild: fix broken builds because of GZIP,BZIP2,LZOP variables samples: binderfs: really compile this sample and fix build issues
2020-06-13Merge tag 'notifications-20200601' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs Pull notification queue from David Howells: "This adds a general notification queue concept and adds an event source for keys/keyrings, such as linking and unlinking keys and changing their attributes. Thanks to Debarshi Ray, we do have a pull request to use this to fix a problem with gnome-online-accounts - as mentioned last time: https://gitlab.gnome.org/GNOME/gnome-online-accounts/merge_requests/47 Without this, g-o-a has to constantly poll a keyring-based kerberos cache to find out if kinit has changed anything. [ There are other notification pending: mount/sb fsinfo notifications for libmount that Karel Zak and Ian Kent have been working on, and Christian Brauner would like to use them in lxc, but let's see how this one works first ] LSM hooks are included: - A set of hooks are provided that allow an LSM to rule on whether or not a watch may be set. Each of these hooks takes a different "watched object" parameter, so they're not really shareable. The LSM should use current's credentials. [Wanted by SELinux & Smack] - A hook is provided to allow an LSM to rule on whether or not a particular message may be posted to a particular queue. This is given the credentials from the event generator (which may be the system) and the watch setter. [Wanted by Smack] I've provided SELinux and Smack with implementations of some of these hooks. WHY === Key/keyring notifications are desirable because if you have your kerberos tickets in a file/directory, your Gnome desktop will monitor that using something like fanotify and tell you if your credentials cache changes. However, we also have the ability to cache your kerberos tickets in the session, user or persistent keyring so that it isn't left around on disk across a reboot or logout. Keyrings, however, cannot currently be monitored asynchronously, so the desktop has to poll for it - not so good on a laptop. This facility will allow the desktop to avoid the need to poll. DESIGN DECISIONS ================ - The notification queue is built on top of a standard pipe. Messages are effectively spliced in. The pipe is opened with a special flag: pipe2(fds, O_NOTIFICATION_PIPE); The special flag has the same value as O_EXCL (which doesn't seem like it will ever be applicable in this context)[?]. It is given up front to make it a lot easier to prohibit splice&co from accessing the pipe. [?] Should this be done some other way? I'd rather not use up a new O_* flag if I can avoid it - should I add a pipe3() system call instead? The pipe is then configured:: ioctl(fds[1], IOC_WATCH_QUEUE_SET_SIZE, queue_depth); ioctl(fds[1], IOC_WATCH_QUEUE_SET_FILTER, &filter); Messages are then read out of the pipe using read(). - It should be possible to allow write() to insert data into the notification pipes too, but this is currently disabled as the kernel has to be able to insert messages into the pipe *without* holding pipe->mutex and the code to make this work needs careful auditing. - sendfile(), splice() and vmsplice() are disabled on notification pipes because of the pipe->mutex issue and also because they sometimes want to revert what they just did - but one or more notification messages might've been interleaved in the ring. - The kernel inserts messages with the wait queue spinlock held. This means that pipe_read() and pipe_write() have to take the spinlock to update the queue pointers. - Records in the buffer are binary, typed and have a length so that they can be of varying size. This allows multiple heterogeneous sources to share a common buffer; there are 16 million types available, of which I've used just a few, so there is scope for others to be used. Tags may be specified when a watchpoint is created to help distinguish the sources. - Records are filterable as types have up to 256 subtypes that can be individually filtered. Other filtration is also available. - Notification pipes don't interfere with each other; each may be bound to a different set of watches. Any particular notification will be copied to all the queues that are currently watching for it - and only those that are watching for it. - When recording a notification, the kernel will not sleep, but will rather mark a queue as having lost a message if there's insufficient space. read() will fabricate a loss notification message at an appropriate point later. - The notification pipe is created and then watchpoints are attached to it, using one of: keyctl_watch_key(KEY_SPEC_SESSION_KEYRING, fds[1], 0x01); watch_mount(AT_FDCWD, "/", 0, fd, 0x02); watch_sb(AT_FDCWD, "/mnt", 0, fd, 0x03); where in both cases, fd indicates the queue and the number after is a tag between 0 and 255. - Watches are removed if either the notification pipe is destroyed or the watched object is destroyed. In the latter case, a message will be generated indicating the enforced watch removal. Things I want to avoid: - Introducing features that make the core VFS dependent on the network stack or networking namespaces (ie. usage of netlink). - Dumping all this stuff into dmesg and having a daemon that sits there parsing the output and distributing it as this then puts the responsibility for security into userspace and makes handling namespaces tricky. Further, dmesg might not exist or might be inaccessible inside a container. - Letting users see events they shouldn't be able to see. TESTING AND MANPAGES ==================== - The keyutils tree has a pipe-watch branch that has keyctl commands for making use of notifications. Proposed manual pages can also be found on this branch, though a couple of them really need to go to the main manpages repository instead. If the kernel supports the watching of keys, then running "make test" on that branch will cause the testing infrastructure to spawn a monitoring process on the side that monitors a notifications pipe for all the key/keyring changes induced by the tests and they'll all be checked off to make sure they happened. https://git.kernel.org/pub/scm/linux/kernel/git/dhowells/keyutils.git/log/?h=pipe-watch - A test program is provided (samples/watch_queue/watch_test) that can be used to monitor for keyrings, mount and superblock events. Information on the notifications is simply logged to stdout" * tag 'notifications-20200601' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs: smack: Implement the watch_key and post_notification hooks selinux: Implement the watch_key security hook keys: Make the KEY_NEED_* perms an enum rather than a mask pipe: Add notification lossage handling pipe: Allow buffers to be marked read-whole-or-error for notifications Add sample notification program watch_queue: Add a key/keyring notification facility security: Add hooks to rule on setting a watch pipe: Add general notification queue support pipe: Add O_NOTIFICATION_PIPE security: Add a hook for the point of notification insertion uapi: General notification queue definitions
2020-06-11samples: binderfs: really compile this sample and fix build issuesMasahiro Yamada
Even after commit c624adc9cb6e ("samples: fix binderfs sample"), this sample is never compiled. 'hostprogs' teaches Kbuild that this is a host program, but not enough to order to compile it. You must add it to 'always-y' to really compile it. Since this sample has never been compiled in upstream, various issues are left unnoticed. [1] compilers without <linux/android/binderfs.h> are still widely used <linux/android/binderfs.h> is only available since commit c13295ad219d ("binderfs: rename header to binderfs.h"), i.e., Linux 5.0 If your compiler is based on UAPI headers older than Linux 5.0, you will see the following error: samples/binderfs/binderfs_example.c:16:10: fatal error: linux/android/binderfs.h: No such file or directory #include <linux/android/binderfs.h> ^~~~~~~~~~~~~~~~~~~~~~~~~~ compilation terminated. You cannot rely on compilers having such a new header. The common approach is to install UAPI headers of this kernel into usr/include, and then add it to the header search path. I added 'depends on HEADERS_INSTALL' in Kconfig, and '-I usr/include' compiler flag in Makefile. [2] compile the sample for target architecture Because headers_install works for the target architecture, only the native compiler was able to build sample code that requires '-I usr/include'. Commit 7f3a59db274c ("kbuild: add infrastructure to build userspace programs") added the new syntax 'userprogs' to compile user-space programs for the target architecture. Use it, and then 'ifndef CROSS_COMPILE' will go away. I added 'depends on CC_CAN_LINK' because $(CC) is not necessarily capable of linking user-space programs. [3] use subdir-y to descend into samples/binderfs Since this directory does not contain any kernel-space code, it has no point in generating built-in.a or modules.order. Replace obj-$(CONFIG_...) with subdir-$(CONFIG_...). [4] -Wunused-variable warning If I compile this, I see the following warning. samples/binderfs/binderfs_example.c: In function 'main': samples/binderfs/binderfs_example.c:21:9: warning: unused variable 'len' [-Wunused-variable] 21 | size_t len; | ^~~ I removed the unused 'len'. [5] CONFIG_ANDROID_BINDERFS is not required Since this is a user-space standalone program, it is independent of the kernel configuration. Remove 'depends on ANDROID_BINDERFS'. Fixes: 9762dc1432e1 ("samples: add binderfs sample program") Fixes: c624adc9cb6e ("samples: fix binderfs sample") Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> Acked-by: Christian Brauner <christian.brauner@ubuntu.com>
2020-06-06Merge tag 'kbuild-v5.8' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild Pull Kbuild updates from Masahiro Yamada: - fix warnings in 'make clean' for ARCH=um, hexagon, h8300, unicore32 - ensure to rebuild all objects when the compiler is upgraded - exclude system headers from dependency tracking and fixdep processing - fix potential bit-size mismatch between the kernel and BPF user-mode helper - add the new syntax 'userprogs' to build user-space programs for the target architecture (the same arch as the kernel) - compile user-space sample code under samples/ for the target arch instead of the host arch - make headers_install fail if a CONFIG option is leaked to user-space - sanitize the output format of scripts/checkstack.pl - handle ARM 'push' instruction in scripts/checkstack.pl - error out before modpost if a module name conflict is found - error out when multiple directories are passed to M= because this feature is broken for a long time - add CONFIG_DEBUG_INFO_COMPRESSED to support compressed debug info - a lot of cleanups of modpost - dump vmlinux symbols out into vmlinux.symvers, and reuse it in the second pass of modpost - do not run the second pass of modpost if nothing in modules is updated - install modules.builtin(.modinfo) by 'make install' as well as by 'make modules_install' because it is useful even when CONFIG_MODULES=n - add new command line variables, GZIP, BZIP2, LZOP, LZMA, LZ4, and XZ to allow users to use alternatives such as pigz, pbzip2, etc. * tag 'kbuild-v5.8' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: (96 commits) kbuild: add variables for compression tools Makefile: install modules.builtin even if CONFIG_MODULES=n mksysmap: Fix the mismatch of '.L' symbols in System.map kbuild: doc: rename LDFLAGS to KBUILD_LDFLAGS modpost: change elf_info->size to size_t modpost: remove is_vmlinux() helper modpost: strip .o from modname before calling new_module() modpost: set have_vmlinux in new_module() modpost: remove mod->skip struct member modpost: add mod->is_vmlinux struct member modpost: remove is_vmlinux() call in check_for_{gpl_usage,unused}() modpost: remove mod->is_dot_o struct member modpost: move -d option in scripts/Makefile.modpost modpost: remove -s option modpost: remove get_next_text() and make {grab,release_}file static modpost: use read_text_file() and get_line() for reading text files modpost: avoid false-positive file open error modpost: fix potential mmap'ed file overrun in get_src_version() modpost: add read_text_file() and get_line() helpers modpost: do not call get_modinfo() for vmlinux(.o) ...
2020-05-19Add sample notification programDavid Howells
The sample program is run like: ./samples/watch_queue/watch_test and watches "/" for mount changes and the current session keyring for key changes: # keyctl add user a a @s 1035096409 # keyctl unlink 1035096409 @s producing: # ./watch_test read() = 16 NOTIFY[000]: ty=000001 sy=02 i=00000110 KEY 2ffc2e5d change=2[linked] aux=1035096409 read() = 16 NOTIFY[000]: ty=000001 sy=02 i=00000110 KEY 2ffc2e5d change=3[unlinked] aux=1035096409 Other events may be produced, such as with a failing disk: read() = 22 NOTIFY[000]: ty=000003 sy=02 i=00000416 USB 3-7.7 dev-reset e=0 r=0 read() = 24 NOTIFY[000]: ty=000002 sy=06 i=00000418 BLOCK 00800050 e=6[critical medium] s=64000ef8 This corresponds to: blk_update_request: critical medium error, dev sdf, sector 1677725432 op 0x0:(READ) flags 0x0 phys_seg 1 prio class 0 in dmesg. Signed-off-by: David Howells <dhowells@redhat.com>
2020-05-17samples: watchdog: use 'userprogs' syntaxMasahiro Yamada
Kbuild now supports the 'userprogs' syntax to compile userspace programs for the same architecture as the kernel. Add the entry to samples/Makefile to put this into the build bot coverage. I also added the CONFIG option guarded by 'depends on CC_CAN_LINK' because $(CC) may not provide libc. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> Acked-by: Sam Ravnborg <sam@ravnborg.org>
2020-05-17samples: timers: use 'userprogs' syntaxMasahiro Yamada
Kbuild now supports the 'userprogs' syntax to compile userspace programs for the same architecture as the kernel. Add the entry to samples/Makefile to put this into the build bot coverage. I also added the CONFIG option guarded by 'depends on CC_CAN_LINK' because $(CC) may not provide libc. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> Acked-by: Sam Ravnborg <sam@ravnborg.org>
2020-05-17samples: auxdisplay: use 'userprogs' syntaxMasahiro Yamada
Kbuild now supports the 'userprogs' syntax to compile userspace programs for the same architecture as the kernel. Add the entry to samples/Makefile to put this into the build bot coverage. I also added the CONFIG option guarded by 'depends on CC_CAN_LINK' because $(CC) may not provide libc. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> Acked-by: Miguel Ojeda <miguel.ojeda.sandonis@gmail.com> Acked-by: Sam Ravnborg <sam@ravnborg.org>
2020-05-17samples: mei: build sample program for target architectureMasahiro Yamada
This userspace program includes UAPI headers exported to usr/include/. 'make headers' always works for the target architecture (i.e. the same architecture as the kernel), so the sample program should be built for the target as well. Kbuild now supports 'userprogs' for that. I also guarded the CONFIG option by 'depends on CC_CAN_LINK' because $(CC) may not provide libc. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> Acked-by: Sam Ravnborg <sam@ravnborg.org>
2020-05-17samples: pidfd: build sample program for target architectureMasahiro Yamada
This userspace program includes UAPI headers exported to usr/include/. 'make headers' always works for the target architecture (i.e. the same architecture as the kernel), so the sample program should be built for the target as well. Kbuild now supports 'userprogs' for that. I also guarded the CONFIG option by 'depends on CC_CAN_LINK' because $(CC) may not provide libc. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> Acked-by: Sam Ravnborg <sam@ravnborg.org>
2020-05-17samples: vfs: build sample programs for target architectureMasahiro Yamada
These userspace programs include UAPI headers exported to usr/include/. 'make headers' always works for the target architecture (i.e. the same architecture as the kernel), so the sample programs should be built for the target as well. Kbuild now supports 'userprogs' for that. I also guarded the CONFIG option by 'depends on CC_CAN_LINK' because $(CC) may not provide libc. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> Acked-by: Sam Ravnborg <sam@ravnborg.org>
2020-05-17samples: hidraw: build sample program for target architectureMasahiro Yamada
This userspace program includes UAPI headers exported to usr/include/. 'make headers' always works for the target architecture (i.e. the same architecture as the kernel), so the sample program should be built for the target as well. Kbuild now supports 'userprogs' for that. I also guarded the CONFIG option by 'depends on CC_CAN_LINK' because $(CC) may not provide libc. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> Acked-by: Sam Ravnborg <sam@ravnborg.org>
2020-05-17samples: uhid: build sample program for target architectureMasahiro Yamada
This userspace program includes UAPI headers exported to usr/include/. 'make headers' always works for the target architecture (i.e. the same architecture as the kernel), so the sample program should be built for the target as well. Kbuild now supports 'userprogs' for that. Add the entry to samples/Makefile to put this into the build bot coverage. I also added the CONFIG option guarded by 'depends on CC_CAN_LINK' because $(CC) may not provide libc. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> Acked-by: Sam Ravnborg <sam@ravnborg.org>
2020-05-17samples: seccomp: build sample programs for target architectureMasahiro Yamada
These userspace programs include UAPI headers exported to usr/include/. 'make headers' always works for the target architecture (i.e. the same architecture as the kernel), so the sample programs should be built for the target as well. Kbuild now supports 'userprogs' for that. I also guarded the CONFIG option by 'depends on CC_CAN_LINK' because $(CC) may not provide libc. The 'ifndef CROSS_COMPILE' is no longer needed. BTW, the -m31 for s390 is left-over code. Commit 5a79859ae0f3 ("s390: remove 31 bit support") killed it. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> Acked-by: Sam Ravnborg <sam@ravnborg.org>
2020-05-05samples: fix binderfs sampleArnd Bergmann
A routine check for misspelled Kconfig symbols showed on instance from last year, the correct symbol name is CONFIG_ANDROID_BINDERFS, not CONFIG_CONFIG_ANDROID_BINDERFS, so the extra prefix must be removed in the Kconfig file to allow enabling the sample. As the actual sample fails to build as a kernel module, change the Makefile enough to get to build as a hostprog instead. Fixes: 9762dc1432e1 ("samples: add binderfs sample program") Signed-off-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Christian Brauner <christian.brauner@ubuntu.com> Link: https://lore.kernel.org/r/20200428212555.2806258-1-arnd@arndb.de Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2019-11-27Merge tag 'trace-v5.5' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace Pull tracing updates from Steven Rostedt: "New tracing features: - New PERMANENT flag to ftrace_ops when attaching a callback to a function. As /proc/sys/kernel/ftrace_enabled when set to zero will disable all attached callbacks in ftrace, this has a detrimental impact on live kernel tracing, as it disables all that it patched. If a ftrace_ops is registered to ftrace with the PERMANENT flag set, it will prevent ftrace_enabled from being disabled, and if ftrace_enabled is already disabled, it will prevent a ftrace_ops with PREMANENT flag set from being registered. - New register_ftrace_direct(). As eBPF would like to register its own trampolines to be called by the ftrace nop locations directly, without going through the ftrace trampoline, this function has been added. This allows for eBPF trampolines to live along side of ftrace, perf, kprobe and live patching. It also utilizes the ftrace enabled_functions file that keeps track of functions that have been modified in the kernel, to allow for security auditing. - Allow for kernel internal use of ftrace instances. Subsystems in the kernel can now create and destroy their own tracing instances which allows them to have their own tracing buffer, and be able to record events without worrying about other users from writing over their data. - New seq_buf_hex_dump() that lets users use the hex_dump() in their seq_buf usage. - Notifications now added to tracing_max_latency to allow user space to know when a new max latency is hit by one of the latency tracers. - Wider spread use of generic compare operations for use of bsearch and friends. - More synthetic event fields may be defined (32 up from 16) - Use of xarray for architectures with sparse system calls, for the system call trace events. This along with small clean ups and fixes" * tag 'trace-v5.5' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: (51 commits) tracing: Enable syscall optimization for MIPS tracing: Use xarray for syscall trace events tracing: Sample module to demonstrate kernel access to Ftrace instances. tracing: Adding new functions for kernel access to Ftrace instances tracing: Fix Kconfig indentation ring-buffer: Fix typos in function ring_buffer_producer ftrace: Use BIT() macro ftrace: Return ENOTSUPP when DYNAMIC_FTRACE_WITH_DIRECT_CALLS is not configured ftrace: Rename ftrace_graph_stub to ftrace_stub_graph ftrace: Add a helper function to modify_ftrace_direct() to allow arch optimization ftrace: Add helper find_direct_entry() to consolidate code ftrace: Add another check for match in register_ftrace_direct() ftrace: Fix accounting bug with direct->count in register_ftrace_direct() ftrace/selftests: Fix spelling mistake "wakeing" -> "waking" tracing: Increase SYNTH_FIELDS_MAX for synthetic_events ftrace/samples: Add a sample module that implements modify_ftrace_direct() ftrace: Add modify_ftrace_direct() tracing: Add missing "inline" in stub function of latency_fsnotify() tracing: Remove stray tab in TRACE_EVAL_MAP_FILE's help text tracing: Use seq_buf_hex_dump() to dump buffers ...
2019-11-22tracing: Sample module to demonstrate kernel access to Ftrace instances.Divya Indi
This is a sample module to demonstrate the use of the newly introduced and exported APIs to access Ftrace instances from within the kernel. Newly introduced APIs used here - 1. Create/Lookup a trace array with the given name. struct trace_array *trace_array_get_by_name(const char *name) 2. Destroy/Remove a trace array. int trace_array_destroy(struct trace_array *tr) 4. Enable/Disable trace events: int trace_array_set_clr_event(struct trace_array *tr, const char *system, const char *event, bool enable); Exported APIs - 1. trace_printk equivalent for instances. int trace_array_printk(struct trace_array *tr, unsigned long ip, const char *fmt, ...); 2. Helper function. void trace_printk_init_buffers(void); 3. To decrement the reference counter. void trace_array_put(struct trace_array *tr) Sample output(contents of /sys/kernel/tracing/instances/sample-instance) NOTE: Tracing disabled after ~5 sec) _-----=> irqs-off / _----=> need-resched | / _---=> hardirq/softirq || / _--=> preempt-depth ||| / delay TASK-PID CPU# |||| TIMESTAMP FUNCTION | | | |||| | | sample-instance-1452 [002] .... 49.430948: simple_thread: trace_array_printk: count=0 sample-instance-1452 [002] .... 49.430951: sample_event: count value=0 at jiffies=4294716608 sample-instance-1452 [002] .... 50.454847: simple_thread: trace_array_printk: count=1 sample-instance-1452 [002] .... 50.454849: sample_event: count value=1 at jiffies=4294717632 sample-instance-1452 [002] .... 51.478748: simple_thread: trace_array_printk: count=2 sample-instance-1452 [002] .... 51.478750: sample_event: count value=2 at jiffies=4294718656 sample-instance-1452 [002] .... 52.502652: simple_thread: trace_array_printk: count=3 sample-instance-1452 [002] .... 52.502655: sample_event: count value=3 at jiffies=4294719680 sample-instance-1452 [002] .... 53.526533: simple_thread: trace_array_printk: count=4 sample-instance-1452 [002] .... 53.526535: sample_event: count value=4 at jiffies=4294720704 sample-instance-1452 [002] .... 54.550438: simple_thread: trace_array_printk: count=5 sample-instance-1452 [002] .... 55.574336: simple_thread: trace_array_printk: count=6 Link: http://lkml.kernel.org/r/1574276919-11119-3-git-send-email-divya.indi@oracle.com Reviewed-by: Aruna Ramakrishna <aruna.ramakrishna@oracle.com> Signed-off-by: Divya Indi <divya.indi@oracle.com> [ Moved to samples/ftrace ] Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2019-11-13ftrace: Add sample module that uses register_ftrace_direct()Steven Rostedt (VMware)
Add a sample module that shows a simple use case for regsiter_ftrace_direct(), and how to use it. Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2019-10-21samples: mei: use hostprogs kbuild constructsTomas Winkler
Use hostprogs kbuild constructs to compile mei sample program mei-amt-version Add CONFIG_SAMPLE_INTEL_MEI option to enable/disable the feature. Signed-off-by: Tomas Winkler <tomas.winkler@intel.com> Link: https://lore.kernel.org/r/20191010132710.4075-1-tomas.winkler@intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-07-15docs: driver-api: add a series of orphaned documentsMauro Carvalho Chehab
There are lots of documents under Documentation/*.txt and a few other orphan documents elsehwere that belong to the driver-API book. Move them to their right place. Reviewed-by: Cornelia Huck <cohuck@redhat.com> # vfio-related parts Acked-by: Logan Gunthorpe <logang@deltatee.com> # switchtec Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
2019-07-15docs: connector: convert to ReST and rename to connector.rstMauro Carvalho Chehab
As it has some function definitions, move them to connector.h. The remaining conversion is actually: - add blank lines and identation in order to identify paragraphs; - fix tables markups; - add some lists markups; - mark literal blocks; - adjust title markups. At its new index.rst, let's add a :orphan: while this is not linked to the main index.rst file, in order to avoid build warnings. Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
2019-06-15kbuild: add CONFIG_HEADERS_INSTALL and loosen the dependency of samplesMasahiro Yamada
Commit 5318321d367c ("samples: disable CONFIG_SAMPLES for UML") used a big hammer to fix the build errors under the samples/ directory. Only some samples actually include uapi headers from usr/include. Introduce CONFIG_HEADERS_INSTALL since 'depends on HEADERS_INSTALL' is clearer than 'depends on !UML'. If this option is enabled, uapi headers are installed before starting directory descending. I added 'depends on HEADERS_INSTALL' to per-sample CONFIG options. This allows UML to compile some samples. $ make ARCH=um allmodconfig samples/ [ snip ] CC [M] samples/configfs/configfs_sample.o CC [M] samples/kfifo/bytestream-example.o CC [M] samples/kfifo/dma-example.o CC [M] samples/kfifo/inttype-example.o CC [M] samples/kfifo/record-example.o CC [M] samples/kobject/kobject-example.o CC [M] samples/kobject/kset-example.o CC [M] samples/trace_events/trace-events-sample.o CC [M] samples/trace_printk/trace-printk.o AR samples/vfio-mdev/built-in.a AR samples/built-in.a Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2019-05-21treewide: Add SPDX license identifier - Makefile/KconfigThomas Gleixner
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>
2019-05-08Merge tag 'kbuild-v5.2' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild Pull Kbuild updates from Masahiro Yamada: - allow users to invoke 'make' out of the source tree - refactor scripts/mkmakefile - deprecate KBUILD_SRC, which was used to track the source tree location for O= build. - fix recordmcount.pl in case objdump output is localized - turn unresolved symbols in external modules to errors from warnings by default; pass KBUILD_MODPOST_WARN=1 to get them back to warnings - generate modules.builtin.modinfo to collect .modinfo data from built-in modules - misc Makefile cleanups * tag 'kbuild-v5.2' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: (21 commits) .gitignore: add more all*.config patterns moduleparam: Save information about built-in modules in separate file Remove MODULE_ALIAS() calls that take undefined macro .gitignore: add leading and trailing slashes to generated directories scripts/tags.sh: fix direct execution of scripts/tags.sh scripts: override locale from environment when running recordmcount.pl samples: kobject: allow CONFIG_SAMPLE_KOBJECT to become y samples: seccomp: turn CONFIG_SAMPLE_SECCOMP into a bool option kbuild: move Documentation to vmlinux-alldirs kbuild: move samples/ to KBUILD_VMLINUX_OBJS modpost: make KBUILD_MODPOST_WARN also configurable for external modules kbuild: check arch/$(SRCARCH)/include/generated before out-of-tree build kbuild: remove unneeded dependency for include/config/kernel.release memory: squash drivers/memory/Makefile.asm-offsets kbuild: use $(srctree) instead of KBUILD_SRC to check out-of-tree build kbuild: mkmakefile: generate a simple wrapper of top Makefile kbuild: mkmakefile: do not check the generated Makefile marker kbuild: allow Kbuild to start from any directory kbuild: pass $(MAKECMDGOALS) to sub-make as is kbuild: fix warning "overriding recipe for target 'Makefile'" ...
2019-05-03samples: kobject: allow CONFIG_SAMPLE_KOBJECT to become yMasahiro Yamada
This sample works well as builtin. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2019-05-03samples: seccomp: turn CONFIG_SAMPLE_SECCOMP into a bool optionMasahiro Yamada
The prompt of CONFIG_SAMPLE_SECCOMP claims this is "loadable module only", which is invalid. samples/seccomp/ only contains host programs, so having it tristate is pointless. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2019-03-20vfs: Add a sample program for the new mount APIDavid Howells
Add a sample program to demonstrate fsopen/fsmount/move_mount to mount something. To make it compile on all arches, irrespective of whether or not syscall numbers are assigned, define the syscall number to -1 if it isn't to cause the kernel to return -ENOSYS. Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2019-01-14samples: add binderfs sample programChristian Brauner
This adds a simple sample program mounting binderfs and adding, then removing a binder device. Hopefully, it will be helpful to users who want to know how binderfs is supposed to be used. Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com> Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2018-10-11samples: disable CONFIG_SAMPLES for UMLMasahiro Yamada
Some samples require headers installation, so commit 3fca1700c4c3 ("kbuild: make samples really depend on headers_install") added such dependency in the top Makefile. However, UML fails to build with CONFIG_SAMPLES=y because UML does not support headers_install. Fixes: 3fca1700c4c3 ("kbuild: make samples really depend on headers_install") Reported-by: Kees Cook <keescook@chromium.org> Cc: David Howells <dhowells@redhat.com> Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2018-06-09samples: mbochs: add DMA_SHARED_BUFFER dependencyArnd Bergmann
The new bochs vbe sample fails to link when DMA_SHARED_BUFFER is disabled: ERROR: "dma_buf_export" [samples/vfio-mdev/mbochs.ko] undefined! ERROR: "dma_buf_fd" [samples/vfio-mdev/mbochs.ko] undefined! This uses a 'select' statement to enable that framework, like all other users do. Fixes: a5e6e6505f38 ("sample: vfio bochs vbe display (host device for bochs-drm)") Signed-off-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2018-06-08sample: vfio bochs vbe display (host device for bochs-drm)Gerd Hoffmann
Display device, demo-ing the vfio dmabuf display interface (VFIO_GFX_PLANE_TYPE_DMABUF). Compatible enough to qemu stdvga that bochs-drm.ko can be used as guest driver. Signed-off-by: Gerd Hoffmann <kraxel@redhat.com> Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2018-06-08sample: vfio mdev display - guest driverGerd Hoffmann
Guest fbdev driver for CONFIG_SAMPLE_VFIO_MDEV_MDPY. Signed-off-by: Gerd Hoffmann <kraxel@redhat.com> Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2018-06-08sample: vfio mdev display - host deviceGerd Hoffmann
Simple framebuffer display, demo-ing the vfio region display interface (VFIO_GFX_PLANE_TYPE_REGION). Signed-off-by: Gerd Hoffmann <kraxel@redhat.com> Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2018-04-10Merge tag 'rproc-v4.17' of git://github.com/andersson/remoteprocLinus Torvalds
Pull remoteproc updates from Bjorn Andersson: - add support for generating coredumps for remoteprocs using devcoredump - add the Qualcomm sysmon driver for intra-remoteproc crash handling - a number of fixes in Qualcomm and IMX drivers * tag 'rproc-v4.17' of git://github.com/andersson/remoteproc: remoteproc: fix null pointer dereference on glink only platforms soc: qcom: qmi: add CONFIG_NET dependency remoteproc: imx_rproc: Slightly simplify code in 'imx_rproc_probe()' remoteproc: imx_rproc: Re-use existing error handling path in 'imx_rproc_probe()' remoteproc: imx_rproc: Fix an error handling path in 'imx_rproc_probe()' samples: Introduce Qualcomm QMI sample client remoteproc: qcom: Introduce sysmon remoteproc: Pass type of shutdown to subdev remove remoteproc: qcom: Register segments for core dump soc: qcom: mdt-loader: Return relocation base remoteproc: Rename "load_rsc_table" to "parse_fw" remoteproc: Add remote processor coredump support remoteproc: Remove null character write of shared mem
2018-03-27soc: qcom: qmi: add CONFIG_NET dependencyArnd Bergmann
Access to the socket API and the root network namespace is only available when networking is enabled: ERROR: "kernel_sendmsg" [drivers/soc/qcom/qmi_helpers.ko] undefined! ERROR: "sock_release" [drivers/soc/qcom/qmi_helpers.ko] undefined! ERROR: "sock_create_kern" [drivers/soc/qcom/qmi_helpers.ko] undefined! ERROR: "kernel_getsockname" [drivers/soc/qcom/qmi_helpers.ko] undefined! ERROR: "init_net" [drivers/soc/qcom/qmi_helpers.ko] undefined! ERROR: "kernel_recvmsg" [drivers/soc/qcom/qmi_helpers.ko] undefined! Adding a dependency on CONFIG_NET lets us build it in all randconfig builds. Fixes: 9b8a11e82615 ("soc: qcom: Introduce QMI encoder/decoder") Acked-by: Andy Gross <andy.gross@linaro.org> Signed-off-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
2018-03-16arch: remove blackfin portArnd Bergmann
The Analog Devices Blackfin port was added in 2007 and was rather active for a while, but all work on it has come to a standstill over time, as Analog have changed their product line-up. Aaron Wu confirmed that the architecture port is no longer relevant, and multiple people suggested removing blackfin independently because of some of its oddities like a non-working SMP port, and the amount of duplication between the chip variants, which cause extra work when doing cross-architecture changes. Link: https://docs.blackfin.uclinux.org/ Acked-by: Aaron Wu <Aaron.Wu@analog.com> Acked-by: Bryan Wu <cooloney@gmail.com> Cc: Steven Miao <realmz6@gmail.com> Cc: Mike Frysinger <vapier@chromium.org> Signed-off-by: Arnd Bergmann <arnd@arndb.de>
2018-02-12samples: Introduce Qualcomm QMI sample clientBjorn Andersson
Introduce a sample driver that register for server notifications and spawn clients for each available test service (service 15). The spawned clients implements the interface for encoding "ping" and "data" requests and decode the responses from the remote. Acked-By: Chris Lew <clew@codeaurora.org> Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
2017-09-14livepatch: introduce shadow variable APIJoe Lawrence
Add exported API for livepatch modules: klp_shadow_get() klp_shadow_alloc() klp_shadow_get_or_alloc() klp_shadow_free() klp_shadow_free_all() that implement "shadow" variables, which allow callers to associate new shadow fields to existing data structures. This is intended to be used by livepatch modules seeking to emulate additions to data structure definitions. See Documentation/livepatch/shadow-vars.txt for a summary of the new shadow variable API, including a few common use cases. See samples/livepatch/livepatch-shadow-* for example modules that demonstrate shadow variables. [jkosina@suse.cz: fix __klp_shadow_get_or_alloc() comment as spotted by Josh] Signed-off-by: Joe Lawrence <joe.lawrence@redhat.com> Acked-by: Josh Poimboeuf <jpoimboe@redhat.com> Acked-by: Miroslav Benes <mbenes@suse.cz> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2017-03-02statx: Add a system call to make enhanced file info availableDavid Howells
Add a system call to make extended file information available, including file creation and some attribute flags where available through the underlying filesystem. The getattr inode operation is altered to take two additional arguments: a u32 request_mask and an unsigned int flags that indicate the synchronisation mode. This change is propagated to the vfs_getattr*() function. Functions like vfs_stat() are now inline wrappers around new functions vfs_statx() and vfs_statx_fd() to reduce stack usage. ======== OVERVIEW ======== The idea was initially proposed as a set of xattrs that could be retrieved with getxattr(), but the general preference proved to be for a new syscall with an extended stat structure. A number of requests were gathered for features to be included. The following have been included: (1) Make the fields a consistent size on all arches and make them large. (2) Spare space, request flags and information flags are provided for future expansion. (3) Better support for the y2038 problem [Arnd Bergmann] (tv_sec is an __s64). (4) Creation time: The SMB protocol carries the creation time, which could be exported by Samba, which will in turn help CIFS make use of FS-Cache as that can be used for coherency data (stx_btime). This is also specified in NFSv4 as a recommended attribute and could be exported by NFSD [Steve French]. (5) Lightweight stat: Ask for just those details of interest, and allow a netfs (such as NFS) to approximate anything not of interest, possibly without going to the server [Trond Myklebust, Ulrich Drepper, Andreas Dilger] (AT_STATX_DONT_SYNC). (6) Heavyweight stat: Force a netfs to go to the server, even if it thinks its cached attributes are up to date [Trond Myklebust] (AT_STATX_FORCE_SYNC). And the following have been left out for future extension: (7) Data version number: Could be used by userspace NFS servers [Aneesh Kumar]. Can also be used to modify fill_post_wcc() in NFSD which retrieves i_version directly, but has just called vfs_getattr(). It could get it from the kstat struct if it used vfs_xgetattr() instead. (There's disagreement on the exact semantics of a single field, since not all filesystems do this the same way). (8) BSD stat compatibility: Including more fields from the BSD stat such as creation time (st_btime) and inode generation number (st_gen) [Jeremy Allison, Bernd Schubert]. (9) Inode generation number: Useful for FUSE and userspace NFS servers [Bernd Schubert]. (This was asked for but later deemed unnecessary with the open-by-handle capability available and caused disagreement as to whether it's a security hole or not). (10) Extra coherency data may be useful in making backups [Andreas Dilger]. (No particular data were offered, but things like last backup timestamp, the data version number and the DOS archive bit would come into this category). (11) Allow the filesystem to indicate what it can/cannot provide: A filesystem can now say it doesn't support a standard stat feature if that isn't available, so if, for instance, inode numbers or UIDs don't exist or are fabricated locally... (This requires a separate system call - I have an fsinfo() call idea for this). (12) Store a 16-byte volume ID in the superblock that can be returned in struct xstat [Steve French]. (Deferred to fsinfo). (13) Include granularity fields in the time data to indicate the granularity of each of the times (NFSv4 time_delta) [Steve French]. (Deferred to fsinfo). (14) FS_IOC_GETFLAGS value. These could be translated to BSD's st_flags. Note that the Linux IOC flags are a mess and filesystems such as Ext4 define flags that aren't in linux/fs.h, so translation in the kernel may be a necessity (or, possibly, we provide the filesystem type too). (Some attributes are made available in stx_attributes, but the general feeling was that the IOC flags were to ext[234]-specific and shouldn't be exposed through statx this way). (15) Mask of features available on file (eg: ACLs, seclabel) [Brad Boyer, Michael Kerrisk]. (Deferred, probably to fsinfo. Finding out if there's an ACL or seclabal might require extra filesystem operations). (16) Femtosecond-resolution timestamps [Dave Chinner]. (A __reserved field has been left in the statx_timestamp struct for this - if there proves to be a need). (17) A set multiple attributes syscall to go with this. =============== NEW SYSTEM CALL =============== The new system call is: int ret = statx(int dfd, const char *filename, unsigned int flags, unsigned int mask, struct statx *buffer); The dfd, filename and flags parameters indicate the file to query, in a similar way to fstatat(). There is no equivalent of lstat() as that can be emulated with statx() by passing AT_SYMLINK_NOFOLLOW in flags. There is also no equivalent of fstat() as that can be emulated by passing a NULL filename to statx() with the fd of interest in dfd. Whether or not statx() synchronises the attributes with the backing store can be controlled by OR'ing a value into the flags argument (this typically only affects network filesystems): (1) AT_STATX_SYNC_AS_STAT tells statx() to behave as stat() does in this respect. (2) AT_STATX_FORCE_SYNC will require a network filesystem to synchronise its attributes with the server - which might require data writeback to occur to get the timestamps correct. (3) AT_STATX_DONT_SYNC will suppress synchronisation with the server in a network filesystem. The resulting values should be considered approximate. mask is a bitmask indicating the fields in struct statx that are of interest to the caller. The user should set this to STATX_BASIC_STATS to get the basic set returned by stat(). It should be noted that asking for more information may entail extra I/O operations. buffer points to the destination for the data. This must be 256 bytes in size. ====================== MAIN ATTRIBUTES RECORD ====================== The following structures are defined in which to return the main attribute set: struct statx_timestamp { __s64 tv_sec; __s32 tv_nsec; __s32 __reserved; }; struct statx { __u32 stx_mask; __u32 stx_blksize; __u64 stx_attributes; __u32 stx_nlink; __u32 stx_uid; __u32 stx_gid; __u16 stx_mode; __u16 __spare0[1]; __u64 stx_ino; __u64 stx_size; __u64 stx_blocks; __u64 __spare1[1]; struct statx_timestamp stx_atime; struct statx_timestamp stx_btime; struct statx_timestamp stx_ctime; struct statx_timestamp stx_mtime; __u32 stx_rdev_major; __u32 stx_rdev_minor; __u32 stx_dev_major; __u32 stx_dev_minor; __u64 __spare2[14]; }; The defined bits in request_mask and stx_mask are: STATX_TYPE Want/got stx_mode & S_IFMT STATX_MODE Want/got stx_mode & ~S_IFMT STATX_NLINK Want/got stx_nlink STATX_UID Want/got stx_uid STATX_GID Want/got stx_gid STATX_ATIME Want/got stx_atime{,_ns} STATX_MTIME Want/got stx_mtime{,_ns} STATX_CTIME Want/got stx_ctime{,_ns} STATX_INO Want/got stx_ino STATX_SIZE Want/got stx_size STATX_BLOCKS Want/got stx_blocks STATX_BASIC_STATS [The stuff in the normal stat struct] STATX_BTIME Want/got stx_btime{,_ns} STATX_ALL [All currently available stuff] stx_btime is the file creation time, stx_mask is a bitmask indicating the data provided and __spares*[] are where as-yet undefined fields can be placed. Time fields are structures with separate seconds and nanoseconds fields plus a reserved field in case we want to add even finer resolution. Note that times will be negative if before 1970; in such a case, the nanosecond fields will also be negative if not zero. The bits defined in the stx_attributes field convey information about a file, how it is accessed, where it is and what it does. The following attributes map to FS_*_FL flags and are the same numerical value: STATX_ATTR_COMPRESSED File is compressed by the fs STATX_ATTR_IMMUTABLE File is marked immutable STATX_ATTR_APPEND File is append-only STATX_ATTR_NODUMP File is not to be dumped STATX_ATTR_ENCRYPTED File requires key to decrypt in fs Within the kernel, the supported flags are listed by: KSTAT_ATTR_FS_IOC_FLAGS [Are any other IOC flags of sufficient general interest to be exposed through this interface?] New flags include: STATX_ATTR_AUTOMOUNT Object is an automount trigger These are for the use of GUI tools that might want to mark files specially, depending on what they are. Fields in struct statx come in a number of classes: (0) stx_dev_*, stx_blksize. These are local system information and are always available. (1) stx_mode, stx_nlinks, stx_uid, stx_gid, stx_[amc]time, stx_ino, stx_size, stx_blocks. These will be returned whether the caller asks for them or not. The corresponding bits in stx_mask will be set to indicate whether they actually have valid values. If the caller didn't ask for them, then they may be approximated. For example, NFS won't waste any time updating them from the server, unless as a byproduct of updating something requested. If the values don't actually exist for the underlying object (such as UID or GID on a DOS file), then the bit won't be set in the stx_mask, even if the caller asked for the value. In such a case, the returned value will be a fabrication. Note that there are instances where the type might not be valid, for instance Windows reparse points. (2) stx_rdev_*. This will be set only if stx_mode indicates we're looking at a blockdev or a chardev, otherwise will be 0. (3) stx_btime. Similar to (1), except this will be set to 0 if it doesn't exist. ======= TESTING ======= The following test program can be used to test the statx system call: samples/statx/test-statx.c Just compile and run, passing it paths to the files you want to examine. The file is built automatically if CONFIG_SAMPLES is enabled. Here's some example output. Firstly, an NFS directory that crosses to another FSID. Note that the AUTOMOUNT attribute is set because transiting this directory will cause d_automount to be invoked by the VFS. [root@andromeda ~]# /tmp/test-statx -A /warthog/data statx(/warthog/data) = 0 results=7ff Size: 4096 Blocks: 8 IO Block: 1048576 directory Device: 00:26 Inode: 1703937 Links: 125 Access: (3777/drwxrwxrwx) Uid: 0 Gid: 4041 Access: 2016-11-24 09:02:12.219699527+0000 Modify: 2016-11-17 10:44:36.225653653+0000 Change: 2016-11-17 10:44:36.225653653+0000 Attributes: 0000000000001000 (-------- -------- -------- -------- -------- -------- ---m---- --------) Secondly, the result of automounting on that directory. [root@andromeda ~]# /tmp/test-statx /warthog/data statx(/warthog/data) = 0 results=7ff Size: 4096 Blocks: 8 IO Block: 1048576 directory Device: 00:27 Inode: 2 Links: 125 Access: (3777/drwxrwxrwx) Uid: 0 Gid: 4041 Access: 2016-11-24 09:02:12.219699527+0000 Modify: 2016-11-17 10:44:36.225653653+0000 Change: 2016-11-17 10:44:36.225653653+0000 Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-12-30vfio-mdev: Fix mtty sample driver buildingAlex Williamson
This sample driver was originally under Documentation/ and was moved to samples, but build support was never adjusted for the new location. Signed-off-by: Alex Williamson <alex.williamson@redhat.com> Reviewed-by: Eric Auger <eric.auger@redhat.com> Tested-by: Eric Auger <eric.auger@redhat.com> Reviewed-by: Kirti Wankhede <kwankhede@nvidia.com>