01 Sep, 2020

1 commit

  • While auditing all module notifiers I noticed a whole bunch of fail
    wrt the return value. Notifiers have a 'special' return semantics.

    As is; NOTIFY_DONE vs NOTIFY_OK is a bit vague; but
    notifier_from_errno(0) results in NOTIFY_OK and NOTIFY_DONE has a
    comment that says "Don't care".

    From this I've used NOTIFY_DONE when the function completely ignores
    the callback and notifier_to_error() isn't used.

    Signed-off-by: Peter Zijlstra (Intel)
    Signed-off-by: Ingo Molnar
    Reviewed-by: Mathieu Desnoyers
    Reviewed-by: Joel Fernandes (Google)
    Reviewed-by: Robert Richter
    Acked-by: Steven Rostedt (VMware)
    Link: https://lore.kernel.org/r/20200818135804.385360407@infradead.org

    Peter Zijlstra
     

16 Jun, 2020

1 commit

  • There is a regular need in the kernel to provide a way to declare having a
    dynamically sized set of trailing elements in a structure. Kernel code should
    always use “flexible array members”[1] for these cases. The older style of
    one-element or zero-length arrays should no longer be used[2].

    [1] https://en.wikipedia.org/wiki/Flexible_array_member
    [2] https://github.com/KSPP/linux/issues/21

    Signed-off-by: Gustavo A. R. Silva

    Gustavo A. R. Silva
     

10 Jun, 2020

2 commits

  • Convert comments that reference mmap_sem to reference mmap_lock instead.

    [akpm@linux-foundation.org: fix up linux-next leftovers]
    [akpm@linux-foundation.org: s/lockaphore/lock/, per Vlastimil]
    [akpm@linux-foundation.org: more linux-next fixups, per Michel]

    Signed-off-by: Michel Lespinasse
    Signed-off-by: Andrew Morton
    Reviewed-by: Vlastimil Babka
    Reviewed-by: Daniel Jordan
    Cc: Davidlohr Bueso
    Cc: David Rientjes
    Cc: Hugh Dickins
    Cc: Jason Gunthorpe
    Cc: Jerome Glisse
    Cc: John Hubbard
    Cc: Laurent Dufour
    Cc: Liam Howlett
    Cc: Matthew Wilcox
    Cc: Peter Zijlstra
    Cc: Ying Han
    Link: http://lkml.kernel.org/r/20200520052908.204642-13-walken@google.com
    Signed-off-by: Linus Torvalds

    Michel Lespinasse
     
  • This change converts the existing mmap_sem rwsem calls to use the new mmap
    locking API instead.

    The change is generated using coccinelle with the following rule:

    // spatch --sp-file mmap_lock_api.cocci --in-place --include-headers --dir .

    @@
    expression mm;
    @@
    (
    -init_rwsem
    +mmap_init_lock
    |
    -down_write
    +mmap_write_lock
    |
    -down_write_killable
    +mmap_write_lock_killable
    |
    -down_write_trylock
    +mmap_write_trylock
    |
    -up_write
    +mmap_write_unlock
    |
    -downgrade_write
    +mmap_write_downgrade
    |
    -down_read
    +mmap_read_lock
    |
    -down_read_killable
    +mmap_read_lock_killable
    |
    -down_read_trylock
    +mmap_read_trylock
    |
    -up_read
    +mmap_read_unlock
    )
    -(&mm->mmap_sem)
    +(mm)

    Signed-off-by: Michel Lespinasse
    Signed-off-by: Andrew Morton
    Reviewed-by: Daniel Jordan
    Reviewed-by: Laurent Dufour
    Reviewed-by: Vlastimil Babka
    Cc: Davidlohr Bueso
    Cc: David Rientjes
    Cc: Hugh Dickins
    Cc: Jason Gunthorpe
    Cc: Jerome Glisse
    Cc: John Hubbard
    Cc: Liam Howlett
    Cc: Matthew Wilcox
    Cc: Peter Zijlstra
    Cc: Ying Han
    Link: http://lkml.kernel.org/r/20200520052908.204642-5-walken@google.com
    Signed-off-by: Linus Torvalds

    Michel Lespinasse
     

16 Apr, 2020

1 commit

  • Open access to monitoring for CAP_PERFMON privileged process. Providing
    the access under CAP_PERFMON capability singly, without the rest of
    CAP_SYS_ADMIN credentials, excludes chances to misuse the credentials
    and makes operation more secure.

    CAP_PERFMON implements the principle of least privilege for performance
    monitoring and observability operations (POSIX IEEE 1003.1e 2.2.2.39
    principle of least privilege: A security design principle that states
    that a process or program be granted only those privileges (e.g.,
    capabilities) necessary to accomplish its legitimate function, and only
    for the time that such privileges are actually required)

    For backward compatibility reasons access to the monitoring remains open
    for CAP_SYS_ADMIN privileged processes but CAP_SYS_ADMIN usage for
    secure monitoring is discouraged with respect to CAP_PERFMON capability.

    Signed-off-by: Alexey Budankov
    Acked-by: James Morris
    Cc: Alexei Starovoitov
    Cc: Andi Kleen
    Cc: Igor Lubashev
    Cc: Jiri Olsa
    Cc: Namhyung Kim
    Cc: Peter Zijlstra
    Cc: Serge Hallyn
    Cc: Song Liu
    Cc: Stephane Eranian
    Cc: Thomas Gleixner
    Cc: intel-gfx@lists.freedesktop.org
    Cc: linux-doc@vger.kernel.org
    Cc: linux-man@vger.kernel.org
    Cc: linux-security-module@vger.kernel.org
    Cc: selinux@vger.kernel.org
    Link: http://lore.kernel.org/lkml/691f1096-b15f-9b12-50a0-c2b93918149e@linux.intel.com
    Signed-off-by: Arnaldo Carvalho de Melo

    Alexey Budankov
     

14 Jan, 2020

1 commit

  • As there's two struct ring_buffers in the kernel, it causes some confusion.
    The other one being the perf ring buffer. It was agreed upon that as neither
    of the ring buffers are generic enough to be used globally, they should be
    renamed as:

    perf's ring_buffer -> perf_buffer
    ftrace's ring_buffer -> trace_buffer

    This implements the changes to the ring buffer that ftrace uses.

    Link: https://lore.kernel.org/r/20191213140531.116b3200@gandalf.local.home

    Signed-off-by: Steven Rostedt (VMware)

    Steven Rostedt (VMware)
     

26 Nov, 2019

1 commit

  • Pull printk updates from Petr Mladek:

    - Allow to print symbolic error names via new %pe modifier.

    - Use pr_warn() instead of the remaining pr_warning() calls. Fix
    formatting of the related lines.

    - Add VSPRINTF entry to MAINTAINERS.

    * tag 'printk-for-5.5' of git://git.kernel.org/pub/scm/linux/kernel/git/pmladek/printk: (32 commits)
    checkpatch: don't warn about new vsprintf pointer extension '%pe'
    MAINTAINERS: Add VSPRINTF
    tools lib api: Renaming pr_warning to pr_warn
    ASoC: samsung: Use pr_warn instead of pr_warning
    lib: cpu_rmap: Use pr_warn instead of pr_warning
    trace: Use pr_warn instead of pr_warning
    dma-debug: Use pr_warn instead of pr_warning
    vgacon: Use pr_warn instead of pr_warning
    fs: afs: Use pr_warn instead of pr_warning
    sh/intc: Use pr_warn instead of pr_warning
    scsi: Use pr_warn instead of pr_warning
    platform/x86: intel_oaktrail: Use pr_warn instead of pr_warning
    platform/x86: asus-laptop: Use pr_warn instead of pr_warning
    platform/x86: eeepc-laptop: Use pr_warn instead of pr_warning
    oprofile: Use pr_warn instead of pr_warning
    of: Use pr_warn instead of pr_warning
    macintosh: Use pr_warn instead of pr_warning
    idsn: Use pr_warn instead of pr_warning
    ide: Use pr_warn instead of pr_warning
    crypto: n2: Use pr_warn instead of pr_warning
    ...

    Linus Torvalds
     

18 Oct, 2019

1 commit

  • As said in commit f2c2cbcc35d4 ("powerpc: Use pr_warn instead of
    pr_warning"), removing pr_warning so all logging messages use a
    consistent _warn style. Let's do it.

    Link: http://lkml.kernel.org/r/20191018031850.48498-17-wangkefeng.wang@huawei.com
    To: linux-kernel@vger.kernel.org
    Signed-off-by: Kefeng Wang
    Acked-by: Robert Richter
    Reviewed-by: Sergey Senozhatsky
    Signed-off-by: Petr Mladek

    Kefeng Wang
     

05 Jul, 2019

1 commit

  • Convert the oprofilefs filesystem to the new internal mount API as the old
    one will be obsoleted and removed. This allows greater flexibility in
    communication of mount parameters between userspace, the VFS and the
    filesystem.

    See Documentation/filesystems/mount_api.txt for more information.

    Signed-off-by: David Howells
    cc: Robert Richter
    cc: oprofile-list@lists.sf.net
    Signed-off-by: Al Viro

    David Howells
     

13 Jun, 2018

1 commit

  • The vmalloc() function has no 2-factor argument form, so multiplication
    factors need to be wrapped in array_size(). This patch replaces cases of:

    vmalloc(a * b)

    with:
    vmalloc(array_size(a, b))

    as well as handling cases of:

    vmalloc(a * b * c)

    with:

    vmalloc(array3_size(a, b, c))

    This does, however, attempt to ignore constant size factors like:

    vmalloc(4 * 1024)

    though any constants defined via macros get caught up in the conversion.

    Any factors with a sizeof() of "unsigned char", "char", and "u8" were
    dropped, since they're redundant.

    The Coccinelle script used for this was:

    // Fix redundant parens around sizeof().
    @@
    type TYPE;
    expression THING, E;
    @@

    (
    vmalloc(
    - (sizeof(TYPE)) * E
    + sizeof(TYPE) * E
    , ...)
    |
    vmalloc(
    - (sizeof(THING)) * E
    + sizeof(THING) * E
    , ...)
    )

    // Drop single-byte sizes and redundant parens.
    @@
    expression COUNT;
    typedef u8;
    typedef __u8;
    @@

    (
    vmalloc(
    - sizeof(u8) * (COUNT)
    + COUNT
    , ...)
    |
    vmalloc(
    - sizeof(__u8) * (COUNT)
    + COUNT
    , ...)
    |
    vmalloc(
    - sizeof(char) * (COUNT)
    + COUNT
    , ...)
    |
    vmalloc(
    - sizeof(unsigned char) * (COUNT)
    + COUNT
    , ...)
    |
    vmalloc(
    - sizeof(u8) * COUNT
    + COUNT
    , ...)
    |
    vmalloc(
    - sizeof(__u8) * COUNT
    + COUNT
    , ...)
    |
    vmalloc(
    - sizeof(char) * COUNT
    + COUNT
    , ...)
    |
    vmalloc(
    - sizeof(unsigned char) * COUNT
    + COUNT
    , ...)
    )

    // 2-factor product with sizeof(type/expression) and identifier or constant.
    @@
    type TYPE;
    expression THING;
    identifier COUNT_ID;
    constant COUNT_CONST;
    @@

    (
    vmalloc(
    - sizeof(TYPE) * (COUNT_ID)
    + array_size(COUNT_ID, sizeof(TYPE))
    , ...)
    |
    vmalloc(
    - sizeof(TYPE) * COUNT_ID
    + array_size(COUNT_ID, sizeof(TYPE))
    , ...)
    |
    vmalloc(
    - sizeof(TYPE) * (COUNT_CONST)
    + array_size(COUNT_CONST, sizeof(TYPE))
    , ...)
    |
    vmalloc(
    - sizeof(TYPE) * COUNT_CONST
    + array_size(COUNT_CONST, sizeof(TYPE))
    , ...)
    |
    vmalloc(
    - sizeof(THING) * (COUNT_ID)
    + array_size(COUNT_ID, sizeof(THING))
    , ...)
    |
    vmalloc(
    - sizeof(THING) * COUNT_ID
    + array_size(COUNT_ID, sizeof(THING))
    , ...)
    |
    vmalloc(
    - sizeof(THING) * (COUNT_CONST)
    + array_size(COUNT_CONST, sizeof(THING))
    , ...)
    |
    vmalloc(
    - sizeof(THING) * COUNT_CONST
    + array_size(COUNT_CONST, sizeof(THING))
    , ...)
    )

    // 2-factor product, only identifiers.
    @@
    identifier SIZE, COUNT;
    @@

    vmalloc(
    - SIZE * COUNT
    + array_size(COUNT, SIZE)
    , ...)

    // 3-factor product with 1 sizeof(type) or sizeof(expression), with
    // redundant parens removed.
    @@
    expression THING;
    identifier STRIDE, COUNT;
    type TYPE;
    @@

    (
    vmalloc(
    - sizeof(TYPE) * (COUNT) * (STRIDE)
    + array3_size(COUNT, STRIDE, sizeof(TYPE))
    , ...)
    |
    vmalloc(
    - sizeof(TYPE) * (COUNT) * STRIDE
    + array3_size(COUNT, STRIDE, sizeof(TYPE))
    , ...)
    |
    vmalloc(
    - sizeof(TYPE) * COUNT * (STRIDE)
    + array3_size(COUNT, STRIDE, sizeof(TYPE))
    , ...)
    |
    vmalloc(
    - sizeof(TYPE) * COUNT * STRIDE
    + array3_size(COUNT, STRIDE, sizeof(TYPE))
    , ...)
    |
    vmalloc(
    - sizeof(THING) * (COUNT) * (STRIDE)
    + array3_size(COUNT, STRIDE, sizeof(THING))
    , ...)
    |
    vmalloc(
    - sizeof(THING) * (COUNT) * STRIDE
    + array3_size(COUNT, STRIDE, sizeof(THING))
    , ...)
    |
    vmalloc(
    - sizeof(THING) * COUNT * (STRIDE)
    + array3_size(COUNT, STRIDE, sizeof(THING))
    , ...)
    |
    vmalloc(
    - sizeof(THING) * COUNT * STRIDE
    + array3_size(COUNT, STRIDE, sizeof(THING))
    , ...)
    )

    // 3-factor product with 2 sizeof(variable), with redundant parens removed.
    @@
    expression THING1, THING2;
    identifier COUNT;
    type TYPE1, TYPE2;
    @@

    (
    vmalloc(
    - sizeof(TYPE1) * sizeof(TYPE2) * COUNT
    + array3_size(COUNT, sizeof(TYPE1), sizeof(TYPE2))
    , ...)
    |
    vmalloc(
    - sizeof(TYPE1) * sizeof(THING2) * (COUNT)
    + array3_size(COUNT, sizeof(TYPE1), sizeof(TYPE2))
    , ...)
    |
    vmalloc(
    - sizeof(THING1) * sizeof(THING2) * COUNT
    + array3_size(COUNT, sizeof(THING1), sizeof(THING2))
    , ...)
    |
    vmalloc(
    - sizeof(THING1) * sizeof(THING2) * (COUNT)
    + array3_size(COUNT, sizeof(THING1), sizeof(THING2))
    , ...)
    |
    vmalloc(
    - sizeof(TYPE1) * sizeof(THING2) * COUNT
    + array3_size(COUNT, sizeof(TYPE1), sizeof(THING2))
    , ...)
    |
    vmalloc(
    - sizeof(TYPE1) * sizeof(THING2) * (COUNT)
    + array3_size(COUNT, sizeof(TYPE1), sizeof(THING2))
    , ...)
    )

    // 3-factor product, only identifiers, with redundant parens removed.
    @@
    identifier STRIDE, SIZE, COUNT;
    @@

    (
    vmalloc(
    - (COUNT) * STRIDE * SIZE
    + array3_size(COUNT, STRIDE, SIZE)
    , ...)
    |
    vmalloc(
    - COUNT * (STRIDE) * SIZE
    + array3_size(COUNT, STRIDE, SIZE)
    , ...)
    |
    vmalloc(
    - COUNT * STRIDE * (SIZE)
    + array3_size(COUNT, STRIDE, SIZE)
    , ...)
    |
    vmalloc(
    - (COUNT) * (STRIDE) * SIZE
    + array3_size(COUNT, STRIDE, SIZE)
    , ...)
    |
    vmalloc(
    - COUNT * (STRIDE) * (SIZE)
    + array3_size(COUNT, STRIDE, SIZE)
    , ...)
    |
    vmalloc(
    - (COUNT) * STRIDE * (SIZE)
    + array3_size(COUNT, STRIDE, SIZE)
    , ...)
    |
    vmalloc(
    - (COUNT) * (STRIDE) * (SIZE)
    + array3_size(COUNT, STRIDE, SIZE)
    , ...)
    |
    vmalloc(
    - COUNT * STRIDE * SIZE
    + array3_size(COUNT, STRIDE, SIZE)
    , ...)
    )

    // Any remaining multi-factor products, first at least 3-factor products
    // when they're not all constants...
    @@
    expression E1, E2, E3;
    constant C1, C2, C3;
    @@

    (
    vmalloc(C1 * C2 * C3, ...)
    |
    vmalloc(
    - E1 * E2 * E3
    + array3_size(E1, E2, E3)
    , ...)
    )

    // And then all remaining 2 factors products when they're not all constants.
    @@
    expression E1, E2;
    constant C1, C2;
    @@

    (
    vmalloc(C1 * C2, ...)
    |
    vmalloc(
    - E1 * E2
    + array_size(E1, E2)
    , ...)
    )

    Signed-off-by: Kees Cook

    Kees Cook
     

30 Mar, 2018

1 commit


02 Nov, 2017

1 commit

  • Many source files in the tree are missing licensing information, which
    makes it harder for compliance tools to determine the correct license.

    By default all files without license information are under the default
    license of the kernel, which is GPL version 2.

    Update the files which contain no license information with the 'GPL-2.0'
    SPDX license identifier. The SPDX identifier is a legally binding
    shorthand, which can be used instead of the full boiler plate text.

    This patch is based on work done by Thomas Gleixner and Kate Stewart and
    Philippe Ombredanne.

    How this work was done:

    Patches were generated and checked against linux-4.14-rc6 for a subset of
    the use cases:
    - file had no licensing information it it.
    - file was a */uapi/* one with no licensing information in it,
    - file was a */uapi/* one with existing licensing information,

    Further patches will be generated in subsequent months to fix up cases
    where non-standard license headers were used, and references to license
    had to be inferred by heuristics based on keywords.

    The analysis to determine which SPDX License Identifier to be applied to
    a file was done in a spreadsheet of side by side results from of the
    output of two independent scanners (ScanCode & Windriver) producing SPDX
    tag:value files created by Philippe Ombredanne. Philippe prepared the
    base worksheet, and did an initial spot review of a few 1000 files.

    The 4.13 kernel was the starting point of the analysis with 60,537 files
    assessed. Kate Stewart did a file by file comparison of the scanner
    results in the spreadsheet to determine which SPDX license identifier(s)
    to be applied to the file. She confirmed any determination that was not
    immediately clear with lawyers working with the Linux Foundation.

    Criteria used to select files for SPDX license identifier tagging was:
    - Files considered eligible had to be source code files.
    - Make and config files were included as candidates if they contained >5
    lines of source
    - File already had some variant of a license header in it (even if
    Reviewed-by: Philippe Ombredanne
    Reviewed-by: Thomas Gleixner
    Signed-off-by: Greg Kroah-Hartman

    Greg Kroah-Hartman
     

02 Mar, 2017

4 commits


25 Dec, 2016

1 commit


18 Dec, 2016

1 commit

  • Pull more vfs updates from Al Viro:
    "In this pile:

    - autofs-namespace series
    - dedupe stuff
    - more struct path constification"

    * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (40 commits)
    ocfs2: implement the VFS clone_range, copy_range, and dedupe_range features
    ocfs2: charge quota for reflinked blocks
    ocfs2: fix bad pointer cast
    ocfs2: always unlock when completing dio writes
    ocfs2: don't eat io errors during _dio_end_io_write
    ocfs2: budget for extent tree splits when adding refcount flag
    ocfs2: prohibit refcounted swapfiles
    ocfs2: add newlines to some error messages
    ocfs2: convert inode refcount test to a helper
    simple_write_end(): don't zero in short copy into uptodate
    exofs: don't mess with simple_write_{begin,end}
    9p: saner ->write_end() on failing copy into non-uptodate page
    fix gfs2_stuffed_write_end() on short copies
    fix ceph_write_end()
    nfs_write_end(): fix handling of short copies
    vfs: refactor clone/dedupe_file_range common functions
    fs: try to clone files first in vfs_copy_file_range
    vfs: misc struct path constification
    namespace.c: constify struct path passed to a bunch of primitives
    quota: constify struct path in quota_on
    ...

    Linus Torvalds
     

06 Dec, 2016

1 commit


02 Dec, 2016

1 commit


11 Oct, 2016

1 commit

  • Pull more vfs updates from Al Viro:
    ">rename2() work from Miklos + current_time() from Deepa"

    * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
    fs: Replace current_fs_time() with current_time()
    fs: Replace CURRENT_TIME_SEC with current_time() for inode timestamps
    fs: Replace CURRENT_TIME with current_time() for inode timestamps
    fs: proc: Delete inode time initializations in proc_alloc_inode()
    vfs: Add current_time() api
    vfs: add note about i_op->rename changes to porting
    fs: rename "rename2" i_op to "rename"
    vfs: remove unused i_op->rename
    fs: make remaining filesystems use .rename2
    libfs: support RENAME_NOREPLACE in simple_rename()
    fs: support RENAME_NOREPLACE for local filesystems
    ncpfs: fix unused variable warning

    Linus Torvalds
     

28 Sep, 2016

1 commit

  • CURRENT_TIME macro is not appropriate for filesystems as it
    doesn't use the right granularity for filesystem timestamps.
    Use current_time() instead.

    CURRENT_TIME is also not y2038 safe.

    This is also in preparation for the patch that transitions
    vfs timestamps to use 64 bit time and hence make them
    y2038 safe. As part of the effort current_time() will be
    extended to do range checks. Hence, it is necessary for all
    file system timestamps to use current_time(). Also,
    current_time() will be transitioned along with vfs to be
    y2038 safe.

    Note that whenever a single call to current_time() is used
    to change timestamps in different inodes, it is because they
    share the same time granularity.

    Signed-off-by: Deepa Dinamani
    Reviewed-by: Arnd Bergmann
    Acked-by: Felipe Balbi
    Acked-by: Steven Whitehouse
    Acked-by: Ryusuke Konishi
    Acked-by: David Sterba
    Signed-off-by: Al Viro

    Deepa Dinamani
     

20 Sep, 2016

1 commit

  • Install the callbacks via the state machine and let the core invoke
    the callbacks on the already online CPUs.
    Since the online target runs always on the target CPU we can drop
    smp_call_function_single(). The functions is invoked with interrupts off to
    keep the old calling convention. If the maintainer things that this function
    can be called with interrupts enabled then it can be removed :)

    Signed-off-by: Sebastian Andrzej Siewior
    Cc: Robert Richter
    Cc: Peter Zijlstra
    Cc: oprofile-list@lists.sf.net
    Cc: rt@linutronix.de
    Link: http://lkml.kernel.org/r/20160906170457.32393-10-bigeasy@linutronix.de
    Signed-off-by: Thomas Gleixner

    Sebastian Andrzej Siewior
     

05 Apr, 2016

1 commit

  • PAGE_CACHE_{SIZE,SHIFT,MASK,ALIGN} macros were introduced *long* time
    ago with promise that one day it will be possible to implement page
    cache with bigger chunks than PAGE_SIZE.

    This promise never materialized. And unlikely will.

    We have many places where PAGE_CACHE_SIZE assumed to be equal to
    PAGE_SIZE. And it's constant source of confusion on whether
    PAGE_CACHE_* or PAGE_* constant should be used in a particular case,
    especially on the border between fs and mm.

    Global switching to PAGE_CACHE_SIZE != PAGE_SIZE would cause to much
    breakage to be doable.

    Let's stop pretending that pages in page cache are special. They are
    not.

    The changes are pretty straight-forward:

    - << (PAGE_CACHE_SHIFT - PAGE_SHIFT) -> ;

    - >> (PAGE_CACHE_SHIFT - PAGE_SHIFT) -> ;

    - PAGE_CACHE_{SIZE,SHIFT,MASK,ALIGN} -> PAGE_{SIZE,SHIFT,MASK,ALIGN};

    - page_cache_get() -> get_page();

    - page_cache_release() -> put_page();

    This patch contains automated changes generated with coccinelle using
    script below. For some reason, coccinelle doesn't patch header files.
    I've called spatch for them manually.

    The only adjustment after coccinelle is revert of changes to
    PAGE_CAHCE_ALIGN definition: we are going to drop it later.

    There are few places in the code where coccinelle didn't reach. I'll
    fix them manually in a separate patch. Comments and documentation also
    will be addressed with the separate patch.

    virtual patch

    @@
    expression E;
    @@
    - E << (PAGE_CACHE_SHIFT - PAGE_SHIFT)
    + E

    @@
    expression E;
    @@
    - E >> (PAGE_CACHE_SHIFT - PAGE_SHIFT)
    + E

    @@
    @@
    - PAGE_CACHE_SHIFT
    + PAGE_SHIFT

    @@
    @@
    - PAGE_CACHE_SIZE
    + PAGE_SIZE

    @@
    @@
    - PAGE_CACHE_MASK
    + PAGE_MASK

    @@
    expression E;
    @@
    - PAGE_CACHE_ALIGN(E)
    + PAGE_ALIGN(E)

    @@
    expression E;
    @@
    - page_cache_get(E)
    + get_page(E)

    @@
    expression E;
    @@
    - page_cache_release(E)
    + put_page(E)

    Signed-off-by: Kirill A. Shutemov
    Acked-by: Michal Hocko
    Signed-off-by: Linus Torvalds

    Kirill A. Shutemov
     

23 Jan, 2016

1 commit

  • parallel to mutex_{lock,unlock,trylock,is_locked,lock_nested},
    inode_foo(inode) being mutex_foo(&inode->i_mutex).

    Please, use those for access to ->i_mutex; over the coming cycle
    ->i_mutex will become rwsem, with ->lookup() done with it held
    only shared.

    Signed-off-by: Al Viro

    Al Viro
     

27 Apr, 2015

1 commit

  • Pull fourth vfs update from Al Viro:
    "d_inode() annotations from David Howells (sat in for-next since before
    the beginning of merge window) + four assorted fixes"

    * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
    RCU pathwalk breakage when running into a symlink overmounting something
    fix I_DIO_WAKEUP definition
    direct-io: only inc/dec inode->i_dio_count for file systems
    fs/9p: fix readdir()
    VFS: assorted d_backing_inode() annotations
    VFS: fs/inode.c helpers: d_inode() annotations
    VFS: fs/cachefiles: d_backing_inode() annotations
    VFS: fs library helpers: d_inode() annotations
    VFS: assorted weird filesystems: d_inode() annotations
    VFS: normal filesystems (and lustre): d_inode() annotations
    VFS: security/: d_inode() annotations
    VFS: security/: d_backing_inode() annotations
    VFS: net/: d_inode() annotations
    VFS: net/unix: d_backing_inode() annotations
    VFS: kernel/: d_inode() annotations
    VFS: audit: d_backing_inode() annotations
    VFS: Fix up some ->d_inode accesses in the chelsio driver
    VFS: Cachefiles should perform fs modifications on the top layer only
    VFS: AF_UNIX sockets should call mknod on the top layer only

    Linus Torvalds
     

17 Apr, 2015

1 commit

  • sync_buffer() needs the mmap_sem for two distinct operations, both only
    occurring upon user context switch handling:

    1) Dealing with the exe_file.

    2) Adding the dcookie data as we need to lookup the vma that
    backs it. This is done via add_sample() and add_data().

    This patch isolates 1), for it will no longer need the mmap_sem for
    serialization. However, for now, make of the more standard
    get_mm_exe_file(), requiring only holding the mmap_sem to read the value,
    and relying on reference counting to make sure that the exe file won't
    dissappear underneath us while doing the get dcookie.

    As a consequence, for 2) we move the mmap_sem locking into where we really
    need it, in lookup_dcookie(). The benefits are twofold: reduce mmap_sem
    hold times, and cleaner code.

    [akpm@linux-foundation.org: export get_mm_exe_file for arch/x86/oprofile/oprofile.ko]
    Signed-off-by: Davidlohr Bueso
    Cc: Robert Richter
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Davidlohr Bueso
     

16 Apr, 2015

1 commit


27 Aug, 2014

1 commit


20 Mar, 2014

1 commit

  • Subsystems that want to register CPU hotplug callbacks, as well as perform
    initialization for the CPUs that are already online, often do it as shown
    below:

    get_online_cpus();

    for_each_online_cpu(cpu)
    init_cpu(cpu);

    register_cpu_notifier(&foobar_cpu_notifier);

    put_online_cpus();

    This is wrong, since it is prone to ABBA deadlocks involving the
    cpu_add_remove_lock and the cpu_hotplug.lock (when running concurrently
    with CPU hotplug operations).

    Instead, the correct and race-free way of performing the callback
    registration is:

    cpu_notifier_register_begin();

    for_each_online_cpu(cpu)
    init_cpu(cpu);

    /* Note the use of the double underscored version of the API */
    __register_cpu_notifier(&foobar_cpu_notifier);

    cpu_notifier_register_done();

    Fix the nmi-timer code in oprofile by using this latter form of callback
    registration.

    Cc: Robert Richter
    Cc: Ingo Molnar
    Signed-off-by: Srivatsa S. Bhat
    Signed-off-by: Rafael J. Wysocki

    Srivatsa S. Bhat
     

04 Sep, 2013

6 commits


15 Jul, 2013

1 commit

  • The __cpuinit type of throwaway sections might have made sense
    some time ago when RAM was more constrained, but now the savings
    do not offset the cost and complications. For example, the fix in
    commit 5e427ec2d0 ("x86: Fix bit corruption at CPU resume time")
    is a good example of the nasty type of bugs that can be created
    with improper use of the various __init prefixes.

    After a discussion on LKML[1] it was decided that cpuinit should go
    the way of devinit and be phased out. Once all the users are gone,
    we can then finally remove the macros themselves from linux/init.h.

    This removes all the remaining one-off uses of the __cpuinit macros
    from all C files in the drivers/* directory.

    [1] https://lkml.org/lkml/2013/5/20/589

    Cc: Greg Kroah-Hartman
    Acked-by: Greg Kroah-Hartman
    Signed-off-by: Paul Gortmaker

    Paul Gortmaker
     

04 Mar, 2013

1 commit

  • 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
    Acked-by: Kees Cook
    Reported-by: Kees Cook
    Signed-off-by: "Eric W. Biederman"

    Eric W. Biederman
     

23 Feb, 2013

1 commit


09 Oct, 2012

1 commit

  • Some security modules and oprofile still uses VM_EXECUTABLE for retrieving
    a task's executable file. After this patch they will use mm->exe_file
    directly. mm->exe_file is protected with mm->mmap_sem, so locking stays
    the same.

    Signed-off-by: Konstantin Khlebnikov
    Acked-by: Chris Metcalf [arch/tile]
    Acked-by: Tetsuo Handa [tomoyo]
    Cc: Alexander Viro
    Cc: Carsten Otte
    Cc: Cyrill Gorcunov
    Cc: Eric Paris
    Cc: H. Peter Anvin
    Cc: Hugh Dickins
    Cc: Ingo Molnar
    Acked-by: James Morris
    Cc: Jason Baron
    Cc: Kentaro Takeda
    Cc: Matt Helsley
    Cc: Nick Piggin
    Cc: Oleg Nesterov
    Cc: Peter Zijlstra
    Cc: Robert Richter
    Cc: Suresh Siddha
    Cc: Venkatesh Pallipadi
    Acked-by: Linus Torvalds
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Konstantin Khlebnikov