Eric Lee / smarc-fsl-linux-kernel

03 Mar, 2017

1 commit

  • a528d35e8   statx: Add a system call to make enhanced file info available ... Browse Code »

    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
    Signed-off-by: Al Viro

    David Howells
     

30 Dec, 2016

1 commit

10 Oct, 2016

1 commit

  • 184892925   samples: move blackfin gptimers-example from Documentation ... Browse Code »

    Move blackfin gptimers-example to samples and remove it from Documentation
    Makefile. Update samples Kconfig and Makefile to build gptimers-example.

    blackfin is the last CONFIG_BUILD_DOCSRC target in Documentation/Makefile.
    Hence this patch also includes changes to remove CONFIG_BUILD_DOCSRC from
    Makefile and lib/Kconfig.debug and updates VIDEO_PCI_SKELETON dependency
    on BUILD_DOCSRC.

    Documentation/Makefile is not deleted to avoid braking make htmldocs and
    make distclean.

    Acked-by: Michal Marek
    Acked-by: Jonathan Corbet
    Reviewed-by: Kees Cook
    Reported-by: Valentin Rothberg
    Reported-by: Paul Gortmaker
    Signed-off-by: Shuah Khan

    Shuah Khan
     

30 Jul, 2016

1 commit

  • 7a1e8b80f   Merge branch 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security ... Browse Code »

    Pull security subsystem updates from James Morris:
    "Highlights:

    - TPM core and driver updates/fixes
    - IPv6 security labeling (CALIPSO)
    - Lots of Apparmor fixes
    - Seccomp: remove 2-phase API, close hole where ptrace can change
    syscall #"

    * 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security: (156 commits)
    apparmor: fix SECURITY_APPARMOR_HASH_DEFAULT parameter handling
    tpm: Add TPM 2.0 support to the Nuvoton i2c driver (NPCT6xx family)
    tpm: Factor out common startup code
    tpm: use devm_add_action_or_reset
    tpm2_i2c_nuvoton: add irq validity check
    tpm: read burstcount from TPM_STS in one 32-bit transaction
    tpm: fix byte-order for the value read by tpm2_get_tpm_pt
    tpm_tis_core: convert max timeouts from msec to jiffies
    apparmor: fix arg_size computation for when setprocattr is null terminated
    apparmor: fix oops, validate buffer size in apparmor_setprocattr()
    apparmor: do not expose kernel stack
    apparmor: fix module parameters can be changed after policy is locked
    apparmor: fix oops in profile_unpack() when policy_db is not present
    apparmor: don't check for vmalloc_addr if kvzalloc() failed
    apparmor: add missing id bounds check on dfa verification
    apparmor: allow SYS_CAP_RESOURCE to be sufficient to prlimit another task
    apparmor: use list_next_entry instead of list_entry_next
    apparmor: fix refcount race when finding a child profile
    apparmor: fix ref count leak when profile sha1 hash is read
    apparmor: check that xindex is in trans_table bounds
    ...

    Linus Torvalds
     

08 Jul, 2016

1 commit

  • f6041c1d8   samples/seccomp: Add standalone config option ... Browse Code »

    Add a separate Kconfig option for SAMPLES_SECCOMP.

    Main reason for this is that, just like other samples, it's forced to
    be a module.

    Without this, since the sample is a target only controlled by
    CONFIG_SECCOMP_FILTER, the samples will be built before include files are
    put in place properly. For example, from an arm64 allmodconfig built with
    "make -sk -j 32" (without specific target), the following happens:

    samples/seccomp/bpf-fancy.c:13:27: fatal error: linux/seccomp.h: No such file or directory
    samples/seccomp/bpf-helper.h:20:50: fatal error: linux/seccomp.h: No such file or directory
    samples/seccomp/dropper.c:20:27: fatal error: linux/seccomp.h: No such file or directory
    samples/seccomp/bpf-direct.c:21:27: fatal error: linux/seccomp.h: No such file or directory

    So, just stick to the same format as other samples.

    Signed-off-by: Olof Johansson
    Signed-off-by: Kees Cook

    Olof Johansson
     

20 Jun, 2016

1 commit

  • aad108aa9   tracing: Add trace_printk sample code ... Browse Code »

    Add sample code to test trace_printk(). The trace_printk() functions should
    never be used in production code. This makes testing it a bit more
    difficult. Having a sample module that can test use cases of trace_printk()
    can help out.

    Currently it just tests trace_printk() where it will be converted into:

    trace_bputs()
    trace_puts()
    trace_bprintk()

    as well as staying as the normal _trace_printk().

    It also tests its use in interrupt context as that will test the auxilery
    buffers.

    Signed-off-by: Steven Rostedt

    Steven Rostedt (Red Hat)
     

28 Apr, 2016

1 commit

  • 14fbff6b4   samples: connector: from Documentation to samples directory ... Browse Code »

    A small bug with the new autoksyms support showed that there are
    two kernel modules in the Documentation directory that qualify
    as samples, while all other samples are in the samples/ directory.

    This patch was originally meant as a workaround for that bug, but
    it has now been solved in a different way. However, I still think
    it makes sense as a cleanup to consolidate all sample code in
    one place.

    Signed-off-by: Arnd Bergmann
    Signed-off-by: Jonathan Corbet

    Arnd Bergmann
     

14 Oct, 2015

1 commit

  • 517982229   configfs: remove old API ... Browse Code »

    Remove the old show_attribute and store_attribute methods and update
    the documentation. Also replace the two C samples with a single new
    one in the proper samples directory where people expect to find it.

    Signed-off-by: Christoph Hellwig
    Signed-off-by: Nicholas Bellinger

    Christoph Hellwig
     

04 Feb, 2015

1 commit

22 Dec, 2014

1 commit

26 Jan, 2013

1 commit

  • d75f717e1   tracing: Remove tracepoint sample code ... Browse Code »

    The tracepoint sample code was used to teach developers how to
    create their own tracepoints. But now the trace_events have been
    added as a higher level that is used directly by developers today.

    Only the trace_event code should use the tracepoint interface
    directly and no new tracepoints should be added.

    Besides, the example had a race condition with the use of the
    ->d_name.name dentry field, as pointed out by Al Viro.

    Best just to remove the code so it wont be used by other developers.

    Link: http://lkml.kernel.org/r/20130123225523.GY4939@ZenIV.linux.org.uk

    Cc: Al Viro
    Acked-by: Mathieu Desnoyers
    Signed-off-by: Steven Rostedt

    Steven Rostedt
     

09 Feb, 2012

1 commit

  • 779b96d20   samples/rpmsg: add an rpmsg driver sample ... Browse Code »

    Add an rpmsg driver sample, which demonstrates how to communicate with
    an AMP-configured remote processor over the rpmsg bus.

    Note how once probed, the driver can immediately start sending messages
    using the rpmsg_send() API, without having to worry about creating endpoints
    or allocating rpmsg addresses: all that work is done by the rpmsg bus,
    and the required information is already embedded in the rpmsg channel
    that the driver is probed with.

    In this sample, the driver simply sends a "Hello World!" message to the remote
    processor repeatedly.

    Designed with Brian Swetland .

    Signed-off-by: Ohad Ben-Cohen
    Cc: Brian Swetland
    Cc: Arnd Bergmann
    Cc: Grant Likely
    Cc: Tony Lindgren
    Cc: Russell King
    Cc: Rusty Russell
    Cc: Andrew Morton
    Cc: Greg KH
    Cc: Stephen Boyd

    Ohad Ben-Cohen
     

01 Nov, 2011

1 commit

23 May, 2011

1 commit

21 Apr, 2011

1 commit

  • d431b2e33   HID: hid-example: fix some build issues ... Browse Code »

    samples/hid-example.o needs some Kconfig and Makefile additions in order
    to build. It should use headers from the build tree, so use
    HEADERS_CHECK to require that those header files be present.

    Change the kconfig symbol from tristate to bool since userspace cannot be
    built as loadable modules.

    However, I don't understand why the userspace header files are not present
    as reported in Andrew's build log, since it builds OK on x86_64 without
    any of these changes.

    Signed-off-by: Randy Dunlap
    Cc: Alan Ott
    Cc: Jiri Kosina
    Signed-off-by: Andrew Morton
    Signed-off-by: Jiri Kosina

    Randy Dunlap
     

31 Mar, 2011

1 commit

22 Mar, 2011

1 commit

30 Oct, 2010

1 commit

11 Aug, 2010

1 commit

  • 5bf2b1932   kfifo: add example files to the kernel sample directory ... Browse Code »

    Add four examples to the kernel sample directory.

    It shows how to handle:
    - a byte stream fifo
    - a integer type fifo
    - a dynamic record sized fifo
    - the fifo DMA functions

    [akpm@linux-foundation.org: coding-style fixes]
    Signed-off-by: Stefani Seibold
    Cc: Greg KH
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Stefani Seibold
     

08 Dec, 2009

1 commit

09 Nov, 2009

1 commit

18 Oct, 2009

1 commit

19 Sep, 2009

1 commit

  • fc5377668   tracing: Remove markers ... Browse Code »

    Now that the last users of markers have migrated to the event
    tracer we can kill off the (now orphan) support code.

    Signed-off-by: Christoph Hellwig
    Acked-by: Mathieu Desnoyers
    Cc: Steven Rostedt
    Cc: Frederic Weisbecker
    LKML-Reference:
    Signed-off-by: Ingo Molnar

    Christoph Hellwig
     

17 Jun, 2009

1 commit

  • eadb8a091   Merge branch 'linus' into tracing/hw-breakpoints ... Browse Code »

    Conflicts:
    arch/x86/Kconfig
    arch/x86/kernel/traps.c
    arch/x86/power/cpu.c
    arch/x86/power/cpu_32.c
    kernel/Makefile

    Semantic conflict:
    arch/x86/kernel/hw_breakpoint.c

    Merge reason: Resolve the conflicts, move from put_cpu_no_sched() to
    put_cpu() in arch/x86/kernel/hw_breakpoint.c.

    Signed-off-by: Ingo Molnar

    Ingo Molnar
     

16 Jun, 2009

1 commit

03 Jun, 2009

1 commit

06 May, 2009

1 commit

  • 96d17980f   tracing/events: make SAMPLE_TRACE_EVENTS default to n ... Browse Code »

    Normally a config should be default to n. This patch also makes the
    sample module-only, like SAMPLE_MARKERS and SAMPLE_TRACEPOINTS.

    [ Impact: don't build trace event sample by default ]

    Signed-off-by: Li Zefan
    Acked-by: Steven Rostedt
    Acked-by: Frederic Weisbecker
    LKML-Reference:
    Signed-off-by: Ingo Molnar

    Li Zefan
     

15 Apr, 2009

1 commit

14 Oct, 2008

1 commit

05 Mar, 2008

1 commit

  • 804defea1   Kprobes: move kprobe examples to samples/ ... Browse Code »

    Move kprobes examples from Documentation/kprobes.txt to under samples/.
    Patch originally by Randy Dunlap.

    o Updated the patch to apply on 2.6.25-rc3
    o Modified examples code to build on multiple architectures. Currently,
    the kprobe and jprobe examples code works for x86 and powerpc
    o Cleaned up unneeded #includes
    o Cleaned up Kconfig per Sam Ravnborg's suggestions to fix build break
    on archs that don't have kretprobes
    o Implemented suggestions by Mathieu Desnoyers on CONFIG_KRETPROBES
    o Included Andrew Morton's cleanup based on x86-git
    o Modified kretprobe_example to act as a arch-agnostic module to
    determine routine execution times:
    Use 'modprobe kretprobe_example func=' to determine
    execution time of func_name in nanoseconds.

    Signed-off-by: Randy Dunlap
    Signed-off-by: Ananth N Mavinakayanahalli
    Acked-by: Mathieu Desnoyers
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Ananth N Mavinakayanahalli
     

25 Jan, 2008

1 commit

20 Oct, 2007

2 commits

  • 31155bc03   Linux Kernel Markers - Samples ... Browse Code »

    Module example showing how to use the Linux Kernel Markers.

    [akpm@linux-foundation.org: coding-style fixes]
    Signed-off-by: Mathieu Desnoyers
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Mathieu Desnoyers
     
  • 267c4025f   markers: Add samples subdir ... Browse Code »

    Begin infrastructure for kernel code samples in the samples/ directory.
    Add its Kconfig and Kbuild files.
    Source its Kconfig file in all arch/ Kconfigs.

    Signed-off-by: Randy Dunlap
    Signed-off-by: Mathieu Desnoyers
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Mathieu Desnoyers