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8 years agopowerpc: implement the DMA_ATTR_NO_WARN attribute
Mauricio Faria de Oliveira [Tue, 11 Oct 2016 20:54:17 +0000 (13:54 -0700)]
powerpc: implement the DMA_ATTR_NO_WARN attribute

Add support for the DMA_ATTR_NO_WARN attribute on powerpc iommu code.

Link: http://lkml.kernel.org/r/1470092390-25451-3-git-send-email-mauricfo@linux.vnet.ibm.com
Signed-off-by: Mauricio Faria de Oliveira <mauricfo@linux.vnet.ibm.com>
Acked-by: Michael Ellerman <mpe@ellerman.id.au>
Cc: Keith Busch <keith.busch@intel.com>
Cc: Jens Axboe <axboe@fb.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Krzysztof Kozlowski <k.kozlowski@samsung.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
8 years agodma-mapping: introduce the DMA_ATTR_NO_WARN attribute
Mauricio Faria de Oliveira [Tue, 11 Oct 2016 20:54:14 +0000 (13:54 -0700)]
dma-mapping: introduce the DMA_ATTR_NO_WARN attribute

Introduce the DMA_ATTR_NO_WARN attribute, and document it.

Link: http://lkml.kernel.org/r/1470092390-25451-2-git-send-email-mauricfo@linux.vnet.ibm.com
Signed-off-by: Mauricio Faria de Oliveira <mauricfo@linux.vnet.ibm.com>
Cc: Keith Busch <keith.busch@intel.com>
Cc: Jens Axboe <axboe@fb.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Krzysztof Kozlowski <k.kozlowski@samsung.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
8 years agorandom: remove unused randomize_range()
Jason Cooper [Tue, 11 Oct 2016 20:54:11 +0000 (13:54 -0700)]
random: remove unused randomize_range()

All call sites for randomize_range have been updated to use the much
simpler and more robust randomize_addr().  Remove the now unnecessary
code.

Link: http://lkml.kernel.org/r/20160803233913.32511-8-jason@lakedaemon.net
Signed-off-by: Jason Cooper <jason@lakedaemon.net>
Acked-by: Kees Cook <keescook@chromium.org>
Cc: "Theodore Ts'o" <tytso@mit.edu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
8 years agounicore32: use simpler API for random address requests
Jason Cooper [Tue, 11 Oct 2016 20:54:08 +0000 (13:54 -0700)]
unicore32: use simpler API for random address requests

Currently, all callers to randomize_range() set the length to 0 and
calculate end by adding a constant to the start address.  We can simplify
the API to remove a bunch of needless checks and variables.

Use the new randomize_addr(start, range) call to set the requested
address.

Link: http://lkml.kernel.org/r/20160803233913.32511-7-jason@lakedaemon.net
Signed-off-by: Jason Cooper <jason@lakedaemon.net>
Acked-by: Kees Cook <keescook@chromium.org>
Cc: "Theodore Ts'o" <tytso@mit.edu>
Cc: Guan Xuetao <gxt@mprc.pku.edu.cn>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
8 years agotile: use simpler API for random address requests
Jason Cooper [Tue, 11 Oct 2016 20:54:05 +0000 (13:54 -0700)]
tile: use simpler API for random address requests

Currently, all callers to randomize_range() set the length to 0 and
calculate end by adding a constant to the start address.  We can simplify
the API to remove a bunch of needless checks and variables.

Use the new randomize_addr(start, range) call to set the requested
address.

Link: http://lkml.kernel.org/r/20160803233913.32511-6-jason@lakedaemon.net
Signed-off-by: Jason Cooper <jason@lakedaemon.net>
Acked-by: Kees Cook <keescook@chromium.org>
Cc: "Theodore Ts'o" <tytso@mit.edu>
Cc: Chris Metcalf <cmetcalf@mellanox.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
8 years agoarm64: use simpler API for random address requests
Jason Cooper [Tue, 11 Oct 2016 20:54:02 +0000 (13:54 -0700)]
arm64: use simpler API for random address requests

Currently, all callers to randomize_range() set the length to 0 and
calculate end by adding a constant to the start address.  We can simplify
the API to remove a bunch of needless checks and variables.

Use the new randomize_addr(start, range) call to set the requested
address.

Link: http://lkml.kernel.org/r/20160803233913.32511-5-jason@lakedaemon.net
Signed-off-by: Jason Cooper <jason@lakedaemon.net>
Acked-by: Will Deacon <will.deacon@arm.com>
Acked-by: Kees Cook <keescook@chromium.org>
Cc: "Russell King - ARM Linux" <linux@arm.linux.org.uk>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
8 years agoARM: use simpler API for random address requests
Jason Cooper [Tue, 11 Oct 2016 20:53:59 +0000 (13:53 -0700)]
ARM: use simpler API for random address requests

Currently, all callers to randomize_range() set the length to 0 and
calculate end by adding a constant to the start address.  We can simplify
the API to remove a bunch of needless checks and variables.

Use the new randomize_addr(start, range) call to set the requested
address.

Link: http://lkml.kernel.org/r/20160803233913.32511-4-jason@lakedaemon.net
Signed-off-by: Jason Cooper <jason@lakedaemon.net>
Acked-by: Kees Cook <keescook@chromium.org>
Cc: "Russell King - ARM Linux" <linux@arm.linux.org.uk>
Cc: "Theodore Ts'o" <tytso@mit.edu>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
8 years agox86: use simpler API for random address requests
Jason Cooper [Tue, 11 Oct 2016 20:53:56 +0000 (13:53 -0700)]
x86: use simpler API for random address requests

Currently, all callers to randomize_range() set the length to 0 and
calculate end by adding a constant to the start address.  We can simplify
the API to remove a bunch of needless checks and variables.

Use the new randomize_addr(start, range) call to set the requested
address.

Link: http://lkml.kernel.org/r/20160803233913.32511-3-jason@lakedaemon.net
Signed-off-by: Jason Cooper <jason@lakedaemon.net>
Acked-by: Kees Cook <keescook@chromium.org>
Cc: "Theodore Ts'o" <tytso@mit.edu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "H . Peter Anvin" <hpa@zytor.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
8 years agorandom: simplify API for random address requests
Jason Cooper [Tue, 11 Oct 2016 20:53:52 +0000 (13:53 -0700)]
random: simplify API for random address requests

To date, all callers of randomize_range() have set the length to 0, and
check for a zero return value.  For the current callers, the only way to
get zero returned is if end <= start.  Since they are all adding a
constant to the start address, this is unnecessary.

We can remove a bunch of needless checks by simplifying the API to do just
what everyone wants, return an address between [start, start + range).

While we're here, s/get_random_int/get_random_long/.  No current call site
is adversely affected by get_random_int(), since all current range
requests are < UINT_MAX.  However, we should match caller expectations to
avoid coming up short (ha!) in the future.

All current callers to randomize_range() chose to use the start address if
randomize_range() failed.  Therefore, we simplify things by just returning
the start address on error.

randomize_range() will be removed once all callers have been converted
over to randomize_addr().

Link: http://lkml.kernel.org/r/20160803233913.32511-2-jason@lakedaemon.net
Signed-off-by: Jason Cooper <jason@lakedaemon.net>
Acked-by: Kees Cook <keescook@chromium.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: "Roberts, William C" <william.c.roberts@intel.com>
Cc: Yann Droneaud <ydroneaud@opteya.com>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: "Theodore Ts'o" <tytso@mit.edu>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "H . Peter Anvin" <hpa@zytor.com>
Cc: Nick Kralevich <nnk@google.com>
Cc: Jeffrey Vander Stoep <jeffv@google.com>
Cc: Daniel Cashman <dcashman@android.com>
Cc: Chris Metcalf <cmetcalf@mellanox.com>
Cc: Guan Xuetao <gxt@mprc.pku.edu.cn>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
8 years agorapidio/rio_cm: use memdup_user() instead of duplicating code
Alexandre Bounine [Tue, 11 Oct 2016 20:53:49 +0000 (13:53 -0700)]
rapidio/rio_cm: use memdup_user() instead of duplicating code

Fix coccinelle warning about duplicating existing memdup_user function.

Link: http://lkml.kernel.org/r/20160811151737.20140-1-alexandre.bounine@idt.com
Link: https://lkml.org/lkml/2016/8/11/29
Signed-off-by: Alexandre Bounine <alexandre.bounine@idt.com>
Reported-by: kbuild test robot <fengguang.wu@intel.com>
Cc: Matt Porter <mporter@kernel.crashing.org>
Cc: Andre van Herk <andre.van.herk@prodrive-technologies.com>
Cc: Barry Wood <barry.wood@idt.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
8 years agoptrace: clear TIF_SYSCALL_TRACE on ptrace detach
Ales Novak [Tue, 11 Oct 2016 20:53:46 +0000 (13:53 -0700)]
ptrace: clear TIF_SYSCALL_TRACE on ptrace detach

On __ptrace_detach(), called from do_exit()->exit_notify()->
forget_original_parent()->exit_ptrace(), the TIF_SYSCALL_TRACE in
thread->flags of the tracee is not cleared up.  This results in the
tracehook_report_syscall_* being called (though there's no longer a tracer
listening to that) upon its further syscalls.

Example scenario - attach "strace" to a running process and kill it (the
strace) with SIGKILL.  You'll see that the syscall trace hooks are still
being called.

The clearing of this flag should be moved from ptrace_detach() to
__ptrace_detach().

Link: http://lkml.kernel.org/r/1472759493-20554-1-git-send-email-alnovak@suse.cz
Signed-off-by: Ales Novak <alnovak@suse.cz>
Acked-by: Oleg Nesterov <oleg@redhat.com>
Cc: Jiri Kosina <jkosina@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
8 years agopipe: cap initial pipe capacity according to pipe-max-size limit
Michael Kerrisk (man-pages) [Tue, 11 Oct 2016 20:53:43 +0000 (13:53 -0700)]
pipe: cap initial pipe capacity according to pipe-max-size limit

This is a patch that provides behavior that is more consistent, and
probably less surprising to users. I consider the change optional, and
welcome opinions about whether it should be applied.

By default, pipes are created with a capacity of 64 kiB.  However,
/proc/sys/fs/pipe-max-size may be set smaller than this value.  In this
scenario, an unprivileged user could thus create a pipe whose initial
capacity exceeds the limit. Therefore, it seems logical to cap the
initial pipe capacity according to the value of pipe-max-size.

The test program shown earlier in this patch series can be used to
demonstrate the effect of the change brought about with this patch:

    # cat /proc/sys/fs/pipe-max-size
    1048576
    # sudo -u mtk ./test_F_SETPIPE_SZ 1
    Initial pipe capacity: 65536
    # echo 10000 > /proc/sys/fs/pipe-max-size
    # cat /proc/sys/fs/pipe-max-size
    16384
    # sudo -u mtk ./test_F_SETPIPE_SZ 1
    Initial pipe capacity: 16384
    # ./test_F_SETPIPE_SZ 1
    Initial pipe capacity: 65536

The last two executions of 'test_F_SETPIPE_SZ' show that pipe-max-size
caps the initial allocation for a new pipe for unprivileged users, but
not for privileged users.

Link: http://lkml.kernel.org/r/31dc7064-2a17-9c5b-1df1-4e3012ee992c@gmail.com
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
Reviewed-by: Vegard Nossum <vegard.nossum@oracle.com>
Cc: Willy Tarreau <w@1wt.eu>
Cc: <socketpair@gmail.com>
Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Cc: Jens Axboe <axboe@fb.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
8 years agopipe: make account_pipe_buffers() return a value, and use it
Michael Kerrisk (man-pages) [Tue, 11 Oct 2016 20:53:40 +0000 (13:53 -0700)]
pipe: make account_pipe_buffers() return a value, and use it

This is an optional patch, to provide a small performance
improvement.  Alter account_pipe_buffers() so that it returns the
new value in user->pipe_bufs. This means that we can refactor
too_many_pipe_buffers_soft() and too_many_pipe_buffers_hard() to
avoid the costs of repeated use of atomic_long_read() to get the
value user->pipe_bufs.

Link: http://lkml.kernel.org/r/93e5f193-1e5e-3e1f-3a20-eae79b7e1310@gmail.com
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
Reviewed-by: Vegard Nossum <vegard.nossum@oracle.com>
Cc: Willy Tarreau <w@1wt.eu>
Cc: <socketpair@gmail.com>
Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Cc: Jens Axboe <axboe@fb.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
8 years agopipe: fix limit checking in alloc_pipe_info()
Michael Kerrisk (man-pages) [Tue, 11 Oct 2016 20:53:37 +0000 (13:53 -0700)]
pipe: fix limit checking in alloc_pipe_info()

The limit checking in alloc_pipe_info() (used by pipe(2) and when
opening a FIFO) has the following problems:

(1) When checking capacity required for the new pipe, the checks against
    the limit in /proc/sys/fs/pipe-user-pages-{soft,hard} are made
    against existing consumption, and exclude the memory required for
    the new pipe capacity. As a consequence: (1) the memory allocation
    throttling provided by the soft limit does not kick in quite as
    early as it should, and (2) the user can overrun the hard limit.

(2) As currently implemented, accounting and checking against the limits
    is done as follows:

    (a) Test whether the user has exceeded the limit.
    (b) Make new pipe buffer allocation.
    (c) Account new allocation against the limits.

    This is racey. Multiple processes may pass point (a) simultaneously,
    and then allocate pipe buffers that are accounted for only in step
    (c).  The race means that the user's pipe buffer allocation could be
    pushed over the limit (by an arbitrary amount, depending on how
    unlucky we were in the race). [Thanks to Vegard Nossum for spotting
    this point, which I had missed.]

This patch addresses the above problems as follows:

* Alter the checks against limits to include the memory required for the
  new pipe.
* Re-order the accounting step so that it precedes the buffer allocation.
  If the accounting step determines that a limit has been reached, revert
  the accounting and cause the operation to fail.

Link: http://lkml.kernel.org/r/8ff3e9f9-23f6-510c-644f-8e70cd1c0bd9@gmail.com
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
Reviewed-by: Vegard Nossum <vegard.nossum@oracle.com>
Cc: Willy Tarreau <w@1wt.eu>
Cc: <socketpair@gmail.com>
Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Cc: Jens Axboe <axboe@fb.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
8 years agopipe: simplify logic in alloc_pipe_info()
Michael Kerrisk (man-pages) [Tue, 11 Oct 2016 20:53:34 +0000 (13:53 -0700)]
pipe: simplify logic in alloc_pipe_info()

Replace an 'if' block that covers most of the code in this function
with a 'goto'. This makes the code a little simpler to read, and also
simplifies the next patch (fix limit checking in alloc_pipe_info())

Link: http://lkml.kernel.org/r/aef030c1-0257-98a9-4988-186efa48530c@gmail.com
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
Reviewed-by: Vegard Nossum <vegard.nossum@oracle.com>
Cc: Willy Tarreau <w@1wt.eu>
Cc: <socketpair@gmail.com>
Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Cc: Jens Axboe <axboe@fb.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
8 years agopipe: fix limit checking in pipe_set_size()
Michael Kerrisk (man-pages) [Tue, 11 Oct 2016 20:53:31 +0000 (13:53 -0700)]
pipe: fix limit checking in pipe_set_size()

The limit checking in pipe_set_size() (used by fcntl(F_SETPIPE_SZ))
has the following problems:

(1) When increasing the pipe capacity, the checks against the limits in
    /proc/sys/fs/pipe-user-pages-{soft,hard} are made against existing
    consumption, and exclude the memory required for the increased pipe
    capacity. The new increase in pipe capacity can then push the total
    memory used by the user for pipes (possibly far) over a limit. This
    can also trigger the problem described next.

(2) The limit checks are performed even when the new pipe capacity is
    less than the existing pipe capacity. This can lead to problems if a
    user sets a large pipe capacity, and then the limits are lowered,
    with the result that the user will no longer be able to decrease the
    pipe capacity.

(3) As currently implemented, accounting and checking against the
    limits is done as follows:

    (a) Test whether the user has exceeded the limit.
    (b) Make new pipe buffer allocation.
    (c) Account new allocation against the limits.

    This is racey. Multiple processes may pass point (a)
    simultaneously, and then allocate pipe buffers that are accounted
    for only in step (c).  The race means that the user's pipe buffer
    allocation could be pushed over the limit (by an arbitrary amount,
    depending on how unlucky we were in the race). [Thanks to Vegard
    Nossum for spotting this point, which I had missed.]

This patch addresses the above problems as follows:

* Perform checks against the limits only when increasing a pipe's
  capacity; an unprivileged user can always decrease a pipe's capacity.
* Alter the checks against limits to include the memory required for
  the new pipe capacity.
* Re-order the accounting step so that it precedes the buffer
  allocation. If the accounting step determines that a limit has
  been reached, revert the accounting and cause the operation to fail.

The program below can be used to demonstrate problems 1 and 2, and the
effect of the fix. The program takes one or more command-line arguments.
The first argument specifies the number of pipes that the program should
create. The remaining arguments are, alternately, pipe capacities that
should be set using fcntl(F_SETPIPE_SZ), and sleep intervals (in
seconds) between the fcntl() operations. (The sleep intervals allow the
possibility to change the limits between fcntl() operations.)

Problem 1
=========

Using the test program on an unpatched kernel, we first set some
limits:

    # echo 0 > /proc/sys/fs/pipe-user-pages-soft
    # echo 1000000000 > /proc/sys/fs/pipe-max-size
    # echo 10000 > /proc/sys/fs/pipe-user-pages-hard    # 40.96 MB

Then show that we can set a pipe with capacity (100MB) that is
over the hard limit

    # sudo -u mtk ./test_F_SETPIPE_SZ 1 100000000
    Initial pipe capacity: 65536
        Loop 1: set pipe capacity to 100000000 bytes
            F_SETPIPE_SZ returned 134217728

Now set the capacity to 100MB twice. The second call fails (which is
probably surprising to most users, since it seems like a no-op):

    # sudo -u mtk ./test_F_SETPIPE_SZ 1 100000000 0 100000000
    Initial pipe capacity: 65536
        Loop 1: set pipe capacity to 100000000 bytes
            F_SETPIPE_SZ returned 134217728
        Loop 2: set pipe capacity to 100000000 bytes
            Loop 2, pipe 0: F_SETPIPE_SZ failed: fcntl: Operation not permitted

With a patched kernel, setting a capacity over the limit fails at the
first attempt:

    # echo 0 > /proc/sys/fs/pipe-user-pages-soft
    # echo 1000000000 > /proc/sys/fs/pipe-max-size
    # echo 10000 > /proc/sys/fs/pipe-user-pages-hard
    # sudo -u mtk ./test_F_SETPIPE_SZ 1 100000000
    Initial pipe capacity: 65536
        Loop 1: set pipe capacity to 100000000 bytes
            Loop 1, pipe 0: F_SETPIPE_SZ failed: fcntl: Operation not permitted

There is a small chance that the change to fix this problem could
break user-space, since there are cases where fcntl(F_SETPIPE_SZ)
calls that previously succeeded might fail. However, the chances are
small, since (a) the pipe-user-pages-{soft,hard} limits are new (in
4.5), and the default soft/hard limits are high/unlimited.  Therefore,
it seems warranted to make these limits operate more precisely (and
behave more like what users probably expect).

Problem 2
=========

Running the test program on an unpatched kernel, we first set some limits:

    # getconf PAGESIZE
    4096
    # echo 0 > /proc/sys/fs/pipe-user-pages-soft
    # echo 1000000000 > /proc/sys/fs/pipe-max-size
    # echo 10000 > /proc/sys/fs/pipe-user-pages-hard    # 40.96 MB

Now perform two fcntl(F_SETPIPE_SZ) operations on a single pipe,
first setting a pipe capacity (10MB), sleeping for a few seconds,
during which time the hard limit is lowered, and then set pipe
capacity to a smaller amount (5MB):

    # sudo -u mtk ./test_F_SETPIPE_SZ 1 10000000 15 5000000 &
    [1] 748
    # Initial pipe capacity: 65536
        Loop 1: set pipe capacity to 10000000 bytes
            F_SETPIPE_SZ returned 16777216
            Sleeping 15 seconds

    # echo 1000 > /proc/sys/fs/pipe-user-pages-hard      # 4.096 MB
    #     Loop 2: set pipe capacity to 5000000 bytes
            Loop 2, pipe 0: F_SETPIPE_SZ failed: fcntl: Operation not permitted

In this case, the user should be able to lower the limit.

With a kernel that has the patch below, the second fcntl()
succeeds:

    # echo 0 > /proc/sys/fs/pipe-user-pages-soft
    # echo 1000000000 > /proc/sys/fs/pipe-max-size
    # echo 10000 > /proc/sys/fs/pipe-user-pages-hard
    # sudo -u mtk ./test_F_SETPIPE_SZ 1 10000000 15 5000000 &
    [1] 3215
    # Initial pipe capacity: 65536
    #     Loop 1: set pipe capacity to 10000000 bytes
            F_SETPIPE_SZ returned 16777216
            Sleeping 15 seconds

    # echo 1000 > /proc/sys/fs/pipe-user-pages-hard

    #     Loop 2: set pipe capacity to 5000000 bytes
            F_SETPIPE_SZ returned 8388608

8x---8x---8x---8x---8x---8x---8x---8x---8x---8x---8x---8x---8x---8x---

/* test_F_SETPIPE_SZ.c

   (C) 2016, Michael Kerrisk; licensed under GNU GPL version 2 or later

   Test operation of fcntl(F_SETPIPE_SZ) for setting pipe capacity
   and interactions with limits defined by /proc/sys/fs/pipe-* files.
*/

#define _GNU_SOURCE
#include <stdio.h>
#include <stdlib.h>
#include <fcntl.h>
#include <unistd.h>

int
main(int argc, char *argv[])
{
    int (*pfd)[2];
    int npipes;
    int pcap, rcap;
    int j, p, s, stime, loop;

    if (argc < 2) {
        fprintf(stderr, "Usage: %s num-pipes "
                "[pipe-capacity sleep-time]...\n", argv[0]);
        exit(EXIT_FAILURE);
    }

    npipes = atoi(argv[1]);

    pfd = calloc(npipes, sizeof (int [2]));
    if (pfd == NULL) {
        perror("calloc");
        exit(EXIT_FAILURE);
    }

    for (j = 0; j < npipes; j++) {
        if (pipe(pfd[j]) == -1) {
            fprintf(stderr, "Loop %d: pipe() failed: ", j);
            perror("pipe");
            exit(EXIT_FAILURE);
        }
    }

    printf("Initial pipe capacity: %d\n", fcntl(pfd[0][0], F_GETPIPE_SZ));

    for (j = 2; j < argc; j += 2 ) {
        loop = j / 2;
        pcap = atoi(argv[j]);
        printf("    Loop %d: set pipe capacity to %d bytes\n", loop, pcap);

        for (p = 0; p < npipes; p++) {
            s = fcntl(pfd[p][0], F_SETPIPE_SZ, pcap);
            if (s == -1) {
                fprintf(stderr, "        Loop %d, pipe %d: F_SETPIPE_SZ "
                        "failed: ", loop, p);
                perror("fcntl");
                exit(EXIT_FAILURE);
            }

            if (p == 0) {
                printf("        F_SETPIPE_SZ returned %d\n", s);
                rcap = s;
            } else {
                if (s != rcap) {
                    fprintf(stderr, "        Loop %d, pipe %d: F_SETPIPE_SZ "
                            "unexpected return: %d\n", loop, p, s);
                    exit(EXIT_FAILURE);
                }
            }

            stime = (j + 1 < argc) ? atoi(argv[j + 1]) : 0;
            if (stime > 0) {
                printf("        Sleeping %d seconds\n", stime);
                sleep(stime);
            }
        }
    }

    exit(EXIT_SUCCESS);
}

8x---8x---8x---8x---8x---8x---8x---8x---8x---8x---8x---8x---8x---8x---

Patch history:

v2
   * Switch order of test in 'if' statement to avoid function call
      (to capability()) in normal path. [This is a fix to a preexisting
      wart in the code. Thanks to Willy Tarreau]
    * Perform (size > pipe_max_size) check before calling
      account_pipe_buffers().  [Thanks to Vegard Nossum]
      Quoting Vegard:

        The potential problem happens if the user passes a very large number
        which will overflow pipe->user->pipe_bufs.

        On 32-bit, sizeof(int) == sizeof(long), so if they pass arg = INT_MAX
        then round_pipe_size() returns INT_MAX. Although it's true that the
        accounting is done in terms of pages and not bytes, so you'd need on
        the order of (1 << 13) = 8192 processes hitting the limit at the same
        time in order to make it overflow, which seems a bit unlikely.

        (See https://lkml.org/lkml/2016/8/12/215 for another discussion on the
        limit checking)

Link: http://lkml.kernel.org/r/1e464945-536b-2420-798b-e77b9c7e8593@gmail.com
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
Reviewed-by: Vegard Nossum <vegard.nossum@oracle.com>
Cc: Willy Tarreau <w@1wt.eu>
Cc: <socketpair@gmail.com>
Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Cc: Jens Axboe <axboe@fb.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
8 years agopipe: refactor argument for account_pipe_buffers()
Michael Kerrisk (man-pages) [Tue, 11 Oct 2016 20:53:28 +0000 (13:53 -0700)]
pipe: refactor argument for account_pipe_buffers()

This is a preparatory patch for following work. account_pipe_buffers()
performs accounting in the 'user_struct'. There is no need to pass a
pointer to a 'pipe_inode_info' struct (which is then dereferenced to
obtain a pointer to the 'user' field). Instead, pass a pointer directly
to the 'user_struct'. This change is needed in preparation for a
subsequent patch that the fixes the limit checking in alloc_pipe_info()
(and the resulting code is a little more logical).

Link: http://lkml.kernel.org/r/7277bf8c-a6fc-4a7d-659c-f5b145c981ab@gmail.com
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
Reviewed-by: Vegard Nossum <vegard.nossum@oracle.com>
Cc: Willy Tarreau <w@1wt.eu>
Cc: <socketpair@gmail.com>
Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Cc: Jens Axboe <axboe@fb.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
8 years agopipe: move limit checking logic into pipe_set_size()
Michael Kerrisk (man-pages) [Tue, 11 Oct 2016 20:53:25 +0000 (13:53 -0700)]
pipe: move limit checking logic into pipe_set_size()

This is a preparatory patch for following work. Move the F_SETPIPE_SZ
limit-checking logic from pipe_fcntl() into pipe_set_size().  This
simplifies the code a little, and allows for reworking required in
a later patch that fixes the limit checking in pipe_set_size()

Link: http://lkml.kernel.org/r/3701b2c5-2c52-2c3e-226d-29b9deb29b50@gmail.com
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
Reviewed-by: Vegard Nossum <vegard.nossum@oracle.com>
Cc: Willy Tarreau <w@1wt.eu>
Cc: <socketpair@gmail.com>
Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Cc: Jens Axboe <axboe@fb.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
8 years agopipe: relocate round_pipe_size() above pipe_set_size()
Michael Kerrisk (man-pages) [Tue, 11 Oct 2016 20:53:22 +0000 (13:53 -0700)]
pipe: relocate round_pipe_size() above pipe_set_size()

Patch series "pipe: fix limit handling", v2.

When changing a pipe's capacity with fcntl(F_SETPIPE_SZ), various limits
defined by /proc/sys/fs/pipe-* files are checked to see if unprivileged
users are exceeding limits on memory consumption.

While documenting and testing the operation of these limits I noticed
that, as currently implemented, these checks have a number of problems:

(1) When increasing the pipe capacity, the checks against the limits
    in /proc/sys/fs/pipe-user-pages-{soft,hard} are made against
    existing consumption, and exclude the memory required for the
    increased pipe capacity. The new increase in pipe capacity can then
    push the total memory used by the user for pipes (possibly far) over
    a limit. This can also trigger the problem described next.

(2) The limit checks are performed even when the new pipe capacity
    is less than the existing pipe capacity. This can lead to problems
    if a user sets a large pipe capacity, and then the limits are
    lowered, with the result that the user will no longer be able to
    decrease the pipe capacity.

(3) As currently implemented, accounting and checking against the
    limits is done as follows:

    (a) Test whether the user has exceeded the limit.
    (b) Make new pipe buffer allocation.
    (c) Account new allocation against the limits.

    This is racey. Multiple processes may pass point (a) simultaneously,
    and then allocate pipe buffers that are accounted for only in step
    (c).  The race means that the user's pipe buffer allocation could be
    pushed over the limit (by an arbitrary amount, depending on how
    unlucky we were in the race). [Thanks to Vegard Nossum for spotting
    this point, which I had missed.]

This patch series addresses these three problems.

This patch (of 8):

This is a minor preparatory patch.  After subsequent patches,
round_pipe_size() will be called from pipe_set_size(), so place
round_pipe_size() above pipe_set_size().

Link: http://lkml.kernel.org/r/91a91fdb-a959-ba7f-b551-b62477cc98a1@gmail.com
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
Reviewed-by: Vegard Nossum <vegard.nossum@oracle.com>
Cc: Willy Tarreau <w@1wt.eu>
Cc: <socketpair@gmail.com>
Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Cc: Jens Axboe <axboe@fb.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
8 years agoautofs: refactor ioctl fn vector in iookup_dev_ioctl()
Tomohiro Kusumi [Tue, 11 Oct 2016 20:53:19 +0000 (13:53 -0700)]
autofs: refactor ioctl fn vector in iookup_dev_ioctl()

cmd part of this struct is the same as an index of itself within
_ioctls[]. In fact this cmd is unused, so we can drop this part.

Link: http://lkml.kernel.org/r/20160831033414.9910.66697.stgit@pluto.themaw.net
Signed-off-by: Tomohiro Kusumi <kusumi.tomohiro@gmail.com>
Signed-off-by: Ian Kent <raven@themaw.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
8 years agoautofs: remove possibly misleading /* #define DEBUG */
Tomohiro Kusumi [Tue, 11 Oct 2016 20:53:16 +0000 (13:53 -0700)]
autofs: remove possibly misleading /* #define DEBUG */

Having this in autofs_i.h gives illusion that uncommenting this enables
pr_debug(), but it doesn't enable all the pr_debug() in autofs because
inclusion order matters.

XFS has the same DEBUG macro in its core header fs/xfs/xfs.h, however XFS
seems to have a rule to include this prior to other XFS headers as well as
kernel headers.  This is not the case with autofs, and DEBUG could be
enabled via Makefile, so autofs should just get rid of this comment to
make the code less confusing.  It's a comment, so there is literally no
functional difference.

Link: http://lkml.kernel.org/r/20160831033409.9910.77067.stgit@pluto.themaw.net
Signed-off-by: Tomohiro Kusumi <kusumi.tomohiro@gmail.com>
Signed-off-by: Ian Kent <raven@themaw.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
8 years agoautofs4: move linux/auto_dev-ioctl.h to uapi/linux
Ian Kent [Tue, 11 Oct 2016 20:53:13 +0000 (13:53 -0700)]
autofs4: move linux/auto_dev-ioctl.h to uapi/linux

Since linux/auto_dev-ioctl.h wasn't included in include/linux/Kbuild
it wasn't moved to uapi/linux as part of the uapi series.

Link: http://lkml.kernel.org/r/20160812024901.12352.10984.stgit@pluto.themaw.net
Signed-off-by: Ian Kent <raven@themaw.net>
Cc: Tomohiro Kusumi <kusumi.tomohiro@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
8 years agoautofs: move inclusion of linux/limits.h to uapi
Tomohiro Kusumi [Tue, 11 Oct 2016 20:53:10 +0000 (13:53 -0700)]
autofs: move inclusion of linux/limits.h to uapi

linux/limits.h should be included by uapi instead of linux/auto_fs.h
so as not to cause compile error in userspace.

 # cat << EOF > ./test1.c
 > #include <stdio.h>
 > #include <linux/auto_fs.h>
 > int main(void) {
 >     return 0;
 > }
 > EOF
 # gcc -Wall -g ./test1.c
 In file included from ./test1.c:2:0:
 /usr/include/linux/auto_fs.h:54:12: error: 'NAME_MAX' undeclared here (not in a function)
   char name[NAME_MAX+1];
             ^

Link: http://lkml.kernel.org/r/20160812024856.12352.24092.stgit@pluto.themaw.net
Signed-off-by: Tomohiro Kusumi <kusumi.tomohiro@gmail.com>
Signed-off-by: Ian Kent <ikent@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
8 years agoautofs: fix print format for ioctl warning message
Tomohiro Kusumi [Tue, 11 Oct 2016 20:53:08 +0000 (13:53 -0700)]
autofs: fix print format for ioctl warning message

All other warnings use "cmd(0x%08x)" and this is the only one with
"cmd(%d)".  (below comes from my userspace debug program, but not
automount daemon)

[ 1139.905676] autofs4:pid:1640:check_dev_ioctl_version: ioctl control interface version mismatch: kernel(1.0), user(0.0), cmd(-1072131215)

Link: http://lkml.kernel.org/r/20160812024851.12352.75458.stgit@pluto.themaw.net
Signed-off-by: Tomohiro Kusumi <kusumi.tomohiro@gmail.com>
Signed-off-by: Ian Kent <ikent@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
8 years agoautofs: add autofs_dev_ioctl_version() for AUTOFS_DEV_IOCTL_VERSION_CMD
Ian Kent [Tue, 11 Oct 2016 20:53:05 +0000 (13:53 -0700)]
autofs: add autofs_dev_ioctl_version() for AUTOFS_DEV_IOCTL_VERSION_CMD

No functional changes, based on the following justification.

1. Make the code more consistent using the ioctl vector _ioctls[],
   rather than assigning NULL only for this ioctl command.
2. Remove goto done; for better maintainability in the long run.
3. The existing code is based on the fact that validate_dev_ioctl()
   sets ioctl version for any command, but AUTOFS_DEV_IOCTL_VERSION_CMD
   should explicitly set it regardless of the default behavior.

Link: http://lkml.kernel.org/r/20160812024846.12352.9885.stgit@pluto.themaw.net
Signed-off-by: Tomohiro Kusumi <kusumi.tomohiro@gmail.com>
Signed-off-by: Ian Kent <ikent@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
8 years agoautofs: fix dev ioctl number range check
Ian Kent [Tue, 11 Oct 2016 20:53:02 +0000 (13:53 -0700)]
autofs: fix dev ioctl number range check

The count of miscellaneous device ioctls in fs/autofs4/autofs_i.h is wrong.

The number of ioctls is the difference between AUTOFS_DEV_IOCTL_VERSION_CMD
and AUTOFS_DEV_IOCTL_ISMOUNTPOINT_CMD (14) not the difference between
AUTOFS_IOC_COUNT and 11 (21).

[kusumi.tomohiro@gmail.com: fix typo that made the count macro negative]
Link: http://lkml.kernel.org/r/20160831033420.9910.16809.stgit@pluto.themaw.net
Link: http://lkml.kernel.org/r/20160812024841.12352.11975.stgit@pluto.themaw.net
Signed-off-by: Ian Kent <raven@themaw.net>
Cc: Tomohiro Kusumi <kusumi.tomohiro@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
8 years agoautofs: fix pr_debug() message
Tomohiro Kusumi [Tue, 11 Oct 2016 20:52:59 +0000 (13:52 -0700)]
autofs: fix pr_debug() message

This isn't a return value, so change the message to indicate the status is
the result of may_umount().

(or locate pr_debug() after put_user() with the same message)

Link: http://lkml.kernel.org/r/20160812024836.12352.74628.stgit@pluto.themaw.net
Signed-off-by: Tomohiro Kusumi <kusumi.tomohiro@gmail.com>
Signed-off-by: Ian Kent <ikent@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
8 years agoautofs: update struct autofs_dev_ioctl in Documentation
Tomohiro Kusumi [Tue, 11 Oct 2016 20:52:56 +0000 (13:52 -0700)]
autofs: update struct autofs_dev_ioctl in Documentation

Sync with changes made by commit 730c9eeca980 ("autofs4: improve
parameter usage") which introduced an union for various ioctl commands
instead of having statically named arg1,2.

This commit simply replaces arg1,2 with the corresponding fields without
changing semantics.

Link: http://lkml.kernel.org/r/20160812024831.12352.24667.stgit@pluto.themaw.net
Signed-off-by: Tomohiro Kusumi <kusumi.tomohiro@gmail.com>
Signed-off-by: Ian Kent <ikent@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
8 years agoautofs: fix Documentation regarding devid on ioctl
Tomohiro Kusumi [Tue, 11 Oct 2016 20:52:53 +0000 (13:52 -0700)]
autofs: fix Documentation regarding devid on ioctl

The explanation on how ioctl handles devid seems incorrect.  Userspace who
calls this ioctl has no input regarding devid, and ioctl implementation
retrieves devid via superblock.

Link: http://lkml.kernel.org/r/20160812024825.12352.13486.stgit@pluto.themaw.net
Signed-off-by: Tomohiro Kusumi <kusumi.tomohiro@gmail.com>
Signed-off-by: Ian Kent <ikent@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
8 years agoautofs: remove AUTOFS_DEVID_LEN
Tomohiro Kusumi [Tue, 11 Oct 2016 20:52:51 +0000 (13:52 -0700)]
autofs: remove AUTOFS_DEVID_LEN

This macro was never used by neither kernel nor userspace, and also
doesn't represent "devid length" in bytes.  (unless it was added to mean
something else).

Link: http://lkml.kernel.org/r/20160812024820.12352.21210.stgit@pluto.themaw.net
Signed-off-by: Tomohiro Kusumi <kusumi.tomohiro@gmail.com>
Signed-off-by: Ian Kent <ikent@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
8 years agoautofs: don't fail to free_dev_ioctl(param)
Tomohiro Kusumi [Tue, 11 Oct 2016 20:52:48 +0000 (13:52 -0700)]
autofs: don't fail to free_dev_ioctl(param)

Returning -ENOTTY here fails to free dynamically allocated param.

Link: http://lkml.kernel.org/r/20160812024815.12352.69153.stgit@pluto.themaw.net
Signed-off-by: Tomohiro Kusumi <kusumi.tomohiro@gmail.com>
Signed-off-by: Ian Kent <ikent@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
8 years agoautofs: remove obsolete sb fields
Tomohiro Kusumi [Tue, 11 Oct 2016 20:52:45 +0000 (13:52 -0700)]
autofs: remove obsolete sb fields

These two were left from commit aa55ddf340c9 ("autofs4: remove unused
ioctls") which removed unused ioctls.

Link: http://lkml.kernel.org/r/20160812024810.12352.96377.stgit@pluto.themaw.net
Signed-off-by: Tomohiro Kusumi <kusumi.tomohiro@gmail.com>
Signed-off-by: Ian Kent <ikent@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
8 years agoautofs: use autofs4_free_ino() to kfree dentry data
Tomohiro Kusumi [Tue, 11 Oct 2016 20:52:42 +0000 (13:52 -0700)]
autofs: use autofs4_free_ino() to kfree dentry data

kfree dentry data allocated by autofs4_new_ino() with autofs4_free_ino()
instead of raw kfree.  (since we have the interface to free autofs_info*)

This patch was modified to remove the need to set the dentry info field to
NULL dew to a change in the previous patch.

Link: http://lkml.kernel.org/r/20160812024805.12352.43650.stgit@pluto.themaw.net
Signed-off-by: Tomohiro Kusumi <kusumi.tomohiro@gmail.com>
Signed-off-by: Ian Kent <raven@themaw.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
8 years agoautofs: remove ino free in autofs4_dir_symlink()
Ian Kent [Tue, 11 Oct 2016 20:52:39 +0000 (13:52 -0700)]
autofs: remove ino free in autofs4_dir_symlink()

The inode allocation failure case in autofs4_dir_symlink() frees the
autofs dentry info of the dentry without setting ->d_fsdata to NULL.

That could lead to a double free so just get rid of the free and leave it
to ->d_release().

Link: http://lkml.kernel.org/r/20160812024759.12352.10653.stgit@pluto.themaw.net
Signed-off-by: Ian Kent <raven@themaw.net>
Cc: Tomohiro Kusumi <kusumi.tomohiro@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
8 years agoautofs: add WARN_ON(1) for non dir/link inode case
Tomohiro Kusumi [Tue, 11 Oct 2016 20:52:36 +0000 (13:52 -0700)]
autofs: add WARN_ON(1) for non dir/link inode case

It's invalid if the given mode is neither dir nor link, so warn on else
case.

Link: http://lkml.kernel.org/r/20160812024754.12352.8536.stgit@pluto.themaw.net
Signed-off-by: Tomohiro Kusumi <kusumi.tomohiro@gmail.com>
Signed-off-by: Ian Kent <raven@themaw.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
8 years agoautofs: fix autofs4_fill_super() error exit handling
Ian Kent [Tue, 11 Oct 2016 20:52:33 +0000 (13:52 -0700)]
autofs: fix autofs4_fill_super() error exit handling

Somewhere along the line the error handling gotos have become incorrect.

Link: http://lkml.kernel.org/r/20160812024749.12352.15100.stgit@pluto.themaw.net
Signed-off-by: Ian Kent <raven@themaw.net>
Cc: Tomohiro Kusumi <kusumi.tomohiro@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
8 years agoautofs: test autofs versions first on sb initialization
Tomohiro Kusumi [Tue, 11 Oct 2016 20:52:31 +0000 (13:52 -0700)]
autofs: test autofs versions first on sb initialization

This patch does what the below comment says.  It could be and it's
considered better to do this first before various functions get called
during initialization.

/* Couldn't this be tested earlier? */

Link: http://lkml.kernel.org/r/20160812024744.12352.43075.stgit@pluto.themaw.net
Signed-off-by: Tomohiro Kusumi <kusumi.tomohiro@gmail.com>
Signed-off-by: Ian Kent <raven@themaw.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
8 years agoautofs: drop unnecessary extern in autofs_i.h
Tomohiro Kusumi [Tue, 11 Oct 2016 20:52:28 +0000 (13:52 -0700)]
autofs: drop unnecessary extern in autofs_i.h

autofs4_kill_sb() doesn't need to be declared as extern, and no other
functions in .h are explicitly declared as extern.

Link: http://lkml.kernel.org/r/20160812024739.12352.99354.stgit@pluto.themaw.net
Signed-off-by: Tomohiro Kusumi <kusumi.tomohiro@gmail.com>
Signed-off-by: Ian Kent <raven@themaw.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
8 years agoautofs: fix typos in Documentation/filesystems/autofs4.txt
Tomohiro Kusumi [Tue, 11 Oct 2016 20:52:25 +0000 (13:52 -0700)]
autofs: fix typos in Documentation/filesystems/autofs4.txt

plus minor whitespace fixes.

Link: http://lkml.kernel.org/r/20160812024734.12352.17122.stgit@pluto.themaw.net
Signed-off-by: Tomohiro Kusumi <kusumi.tomohiro@gmail.com>
Signed-off-by: Ian Kent <raven@themaw.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
8 years agokprobes: include <asm/sections.h> instead of <asm-generic/sections.h>
Christoph Hellwig [Tue, 11 Oct 2016 20:52:22 +0000 (13:52 -0700)]
kprobes: include <asm/sections.h> instead of <asm-generic/sections.h>

asm-generic headers are generic implementations for architecture specific
code and should not be included by common code.  Thus use the asm/ version
of sections.h to get at the linker sections.

Link: http://lkml.kernel.org/r/1473602302-6208-1-git-send-email-hch@lst.de
Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
8 years agocheckpatch: improve the octal permissions tests
Joe Perches [Tue, 11 Oct 2016 20:52:19 +0000 (13:52 -0700)]
checkpatch: improve the octal permissions tests

The function calls with octal permissions commonly span multiple lines.
The current test is line oriented and fails to find some matches.

Make the test use the $stat variable instead of the $line variable to span
multiple lines.

Also add a few functions to the known functions with permissions list.

Move the SYMBOLIC_PERMS test to a separate section to find all the S_<FOO>
permissions in any form not just those that have specific function names.

This can now find and fix permissions uses like:
     .mode = S_<FOO> | S_<BAR>;

Link: http://lkml.kernel.org/r/b51bab60530912aae4ac420119d465c5b206f19f.1475030406.git.joe@perches.com
Signed-off-by: Joe Perches <joe@perches.com>
Tested-by: Ramiro Oliveira <roliveir@synopsys.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
8 years agocheckpatch: add warning for unnamed function definition arguments
Joe Perches [Tue, 11 Oct 2016 20:52:16 +0000 (13:52 -0700)]
checkpatch: add warning for unnamed function definition arguments

Function definitions without identifiers like
 int foo(int)
are not preferred.  Emit a warning when they occur.

Link: http://lkml.kernel.org/r/94fe6378504745991b650f48fc92bb4648f25706.1474925354.git.joe@perches.com
Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
8 years agocheckpatch: improve MACRO_ARG_PRECEDENCE test
Joe Perches [Tue, 11 Oct 2016 20:52:14 +0000 (13:52 -0700)]
checkpatch: improve MACRO_ARG_PRECEDENCE test

It is possible for a multiple line macro definition to have a false positive
report when an argument is used on a line after a continuation \.

This line might have a leading '+' as the initial character that could be
confused by checkpatch as an operator.

Avoid the leading character on multiple line macro definitions.

Link: http://lkml.kernel.org/r/60229d13399f9b6509db5a32e30d4c16951a60cd.1473836073.git.joe@perches.com
Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
8 years agocheckpatch: add --strict test for precedence challenged macro arguments
Joe Perches [Tue, 11 Oct 2016 20:52:11 +0000 (13:52 -0700)]
checkpatch: add --strict test for precedence challenged macro arguments

Add a test for macro arguents that have a non-comma leading or trailing
operator where the argument isn't parenthesized to avoid possible precedence
issues.

Link: http://lkml.kernel.org/r/47715508972f8d786f435e583ff881dbeee3a114.1473745855.git.joe@perches.com
Signed-off-by: Joe Perches <joe@perches.com>
Cc: Andy Whitcroft <apw@canonical.com>
Cc: Julia Lawall <julia.lawall@lip6.fr>
Cc: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
8 years agocheckpatch: add --strict test for macro argument reuse
Joe Perches [Tue, 11 Oct 2016 20:52:08 +0000 (13:52 -0700)]
checkpatch: add --strict test for macro argument reuse

If a macro argument is used multiple times in the macro definition, the
macro argument may have an unexpected side-effect.

Add a test (MACRO_ARG_REUSE) for that condition which is only
emitted with command-line option --strict.

Link: http://lkml.kernel.org/r/b6d67a87cafcafd15499e91780dc63b15dec0aa0.1473744906.git.joe@perches.com
Signed-off-by: Joe Perches <joe@perches.com>
Cc: Andy Whitcroft <apw@canonical.com>
Cc: Julia Lawall <julia.lawall@lip6.fr>
Cc: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
8 years agocheckpatch: improve the block comment * alignment test
Joe Perches [Tue, 11 Oct 2016 20:52:05 +0000 (13:52 -0700)]
checkpatch: improve the block comment * alignment test

An "uninitialized value" is emitted when a block comment starts on
the same line as a statement.

Fix this and make the test use a little fewer cpu cycles too.

Link: http://lkml.kernel.org/r/3c9993320c2182d37f53ac540878cfef59c3f62d.1473365956.git.joe@perches.com
Signed-off-by: Joe Perches <joe@perches.com>
Reported-by: Charlemagne Lasse <charlemagnelasse@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
8 years agocheckpatch: speed up checking for filenames in sections marked obsolete
Joe Perches [Tue, 11 Oct 2016 20:52:02 +0000 (13:52 -0700)]
checkpatch: speed up checking for filenames in sections marked obsolete

Adding -f to the get_maintainer.pl invocation means git isn't invoked
by get_maintainer.pl for known filenames.

This reduces the overall time to run checkpatch.

Link: http://lkml.kernel.org/r/22991e3a295aeb399b43af0478b6e5809106ccee.1472684066.git.joe@perches.com
Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
8 years agoconst_structs.checkpatch: add frequently used from Julia Lawall's list
Joe Perches [Tue, 11 Oct 2016 20:51:59 +0000 (13:51 -0700)]
const_structs.checkpatch: add frequently used from Julia Lawall's list

Using const is generally a good idea.

Julia Lawall has created a list of always const and almost always const
structs in the kernel sources.

Link: https://lkml.org/lkml/2016/8/28/95
Add the most frequently used (> 50 cases) that are almost always or
always const.

Link: http://lkml.kernel.org/r/1e16020f8027654db0095bbfbcc11da51025365c.1472664220.git.joe@perches.com
Signed-off-by: Joe Perches <joe@perches.com>
Acked-by: Kees Cook <keescook@chromium.org>
Cc: Julia Lawall <julia.lawall@lip6.fr>
Cc: Andy Whitcroft <apw@canonical.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
8 years agocheckpatch: externalize the structs that should be const
Joe Perches [Tue, 11 Oct 2016 20:51:56 +0000 (13:51 -0700)]
checkpatch: externalize the structs that should be const

Make it easier to add new structs that should be const.

Link: http://lkml.kernel.org/r/e5a8da43e7c11525bafbda1ca69a8323614dd942.1472664220.git.joe@perches.com
Signed-off-by: Joe Perches <joe@perches.com>
Cc: Julia Lawall <julia.lawall@lip6.fr>
Cc: Kees Cook <keescook@chromium.org>
Cc: Andy Whitcroft <apw@canonical.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
8 years agocheckpatch: don't test for prefer ether_addr_<foo>
Joe Perches [Tue, 11 Oct 2016 20:51:53 +0000 (13:51 -0700)]
checkpatch: don't test for prefer ether_addr_<foo>

< sigh > Comment these tests out.

These are just too enticing to people that don't verify that
both source and dest addresses really must be __aligned(2).

It helps make Dan Carpenter happy too.

Link: http://lkml.kernel.org/r/dc32ec66d24647f4cdf824c8dfbbc59aa7ce7b7d.1472665676.git.joe@perches.com
Signed-off-by: Joe Perches <joe@perches.com>
Cc: Dan Carpenter <dan.carpenter@oracle.com>
Cc: Greg <gvrose8192@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
8 years agocheckpatch: test multiple line block comment alignment
Joe Perches [Tue, 11 Oct 2016 20:51:50 +0000 (13:51 -0700)]
checkpatch: test multiple line block comment alignment

Warn when block comments are not aligned on the *

/*
 * block comment, no warning
 */

/*
  * block comment, emit warning
  */

Link: http://lkml.kernel.org/r/edb57bd330adfe024b95ec2a807d4aa7f0c8b112.1472261299.git.joe@perches.com
Signed-off-by: Joe Perches <joe@perches.com>
Reported-by: Sudip Mukherjee <sudipm.mukherjee@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
8 years agocheckpatch: look for symbolic permissions and suggest octal instead
Joe Perches [Tue, 11 Oct 2016 20:51:47 +0000 (13:51 -0700)]
checkpatch: look for symbolic permissions and suggest octal instead

S_<FOO> uses should be avoided where octal is more intelligible.

Linus didst say:

: It's *much* easier to parse and understand the octal numbers, while the
: symbolic macro names are just random line noise and hard as hell to
: understand.  You really have to think about it.
:
: So we should rather go the other way: convert existing bad symbolic
: permission bit macro use to just use the octal numbers.
:
: The symbolic names are good for the *other* bits (ie sticky bit, and the
: inode mode _type_ numbers etc), but for the permission bits, the symbolic
: names are just insane crap.  Nobody sane should ever use them.  Not in the
: kernel, not in user space.
(http://lkml.kernel.org/r/CA+55aFw5v23T-zvDZp-MmD_EYxF8WbafwwB59934FV7g21uMGQ@mail.gmail.com)

Link: http://lkml.kernel.org/r/7232ef011d05a92f4caa86a5e9830d87966a2eaf.1470180926.git.joe@perches.com
Signed-off-by: Joe Perches <joe@perches.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
8 years agocheckpatch: see if modified files are marked obsolete in MAINTAINERS
Joe Perches [Tue, 11 Oct 2016 20:51:44 +0000 (13:51 -0700)]
checkpatch: see if modified files are marked obsolete in MAINTAINERS

Use get_maintainer to check the status of individual files.  If
"obsolete", suggest leaving the files alone.

Link: http://lkml.kernel.org/r/7ceaa510dc9d2df05ec4b456baed7bb1415550b3.1471889575.git.joe@perches.com
Signed-off-by: Joe Perches <joe@perches.com>
Cc: SF Markus Elfring <elfring@users.sourceforge.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
8 years agolib/bitmap.c: enhance bitmap syntax
Noam Camus [Tue, 11 Oct 2016 20:51:35 +0000 (13:51 -0700)]
lib/bitmap.c: enhance bitmap syntax

Today there are platforms with many CPUs (up to 4K).  Trying to boot only
part of the CPUs may result in too long string.

For example lets take NPS platform that is part of arch/arc.  This
platform have SMP system with 256 cores each with 16 HW threads (SMT
machine) where HW thread appears as CPU to the kernel.  In this example
there is total of 4K CPUs.  When one tries to boot only part of the HW
threads from each core the string representing the map may be long...  For
example if for sake of performance we decided to boot only first half of
HW threads of each core the map will look like:
0-7,16-23,32-39,...,4080-4087

This patch introduce new syntax to accommodate with such use case.  I
added an optional postfix to a range of CPUs which will choose according
to given modulo the desired range of reminders i.e.:

    <cpus range>:sed_size/group_size

For example, above map can be described in new syntax like this:
0-4095:8/16

Note that this patch is backward compatible with current syntax.

[akpm@linux-foundation.org: rework documentation]
Link: http://lkml.kernel.org/r/1473579629-4283-1-git-send-email-noamca@mellanox.com
Signed-off-by: Noam Camus <noamca@mellanox.com>
Cc: David Decotigny <decot@googlers.com>
Cc: Ben Hutchings <ben@decadent.org.uk>
Cc: David S. Miller <davem@davemloft.net>
Cc: Pan Xinhui <xinhui@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
8 years agolib/kstrtox.c: smaller _parse_integer()
Alexey Dobriyan [Tue, 11 Oct 2016 20:51:32 +0000 (13:51 -0700)]
lib/kstrtox.c: smaller _parse_integer()

Set "overflow" bit upon encountering it instead of postponing to the end
of the conversion. Somehow gcc unwedges itself and generates better code:

$ ./scripts/bloat-o-meter ../vmlinux-000 ../obj/vmlinux
_parse_integer                      177     139     -38

Inspired by patch from Zhaoxiu Zeng.

Link: http://lkml.kernel.org/r/20160826221920.GA1909@p183.telecom.by
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
8 years agoinclude/linux/ctype.h: make isdigit() table lookupless
Alexey Dobriyan [Tue, 11 Oct 2016 20:51:30 +0000 (13:51 -0700)]
include/linux/ctype.h: make isdigit() table lookupless

Make isdigit into a simple range checking inline function:

return '0' <= c && c <= '9';

This code is 1 branch, not 2 because any reasonable compiler can
optimize this code into SUB+CMP, so the code

while (isdigit((c = *s++)))
...

remains 1 branch per iteration HOWEVER it suddenly doesn't do table
lookup priming cacheline nobody cares about.

Link: http://lkml.kernel.org/r/20160826190047.GA12536@p183.telecom.by
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
8 years agolib: harden strncpy_from_user
Mark Rutland [Tue, 11 Oct 2016 20:51:27 +0000 (13:51 -0700)]
lib: harden strncpy_from_user

The strncpy_from_user() accessor is effectively a copy_from_user()
specialised to copy strings, terminating early at a NUL byte if possible.
In other respects it is identical, and can be used to copy an arbitrarily
large buffer from userspace into the kernel.  Conceptually, it exposes a
similar attack surface.

As with copy_from_user(), we check the destination range when the kernel
is built with KASAN, but unlike copy_from_user() we do not check the
destination buffer when using HARDENED_USERCOPY.  As strncpy_from_user()
calls get_user() in a loop, we must call check_object_size() explicitly.

This patch adds this instrumentation to strncpy_from_user(), per the same
rationale as with the regular copy_from_user().  In the absence of
hardened usercopy this will have no impact as the instrumentation expands
to an empty static inline function.

Link: http://lkml.kernel.org/r/1472221903-31181-1-git-send-email-mark.rutland@arm.com
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Cc: Kees Cook <keescook@chromium.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
8 years agoradix-tree tests: properly initialize mutex
Ross Zwisler [Tue, 11 Oct 2016 20:51:24 +0000 (13:51 -0700)]
radix-tree tests: properly initialize mutex

The pthread_mutex_t in regression1.c wasn't being initialized properly.

Link: http://lkml.kernel.org/r/20160815194237.25967-4-ross.zwisler@linux.intel.com
Signed-off-by: Ross Zwisler <ross.zwisler@linux.intel.com>
Cc: Konstantin Khlebnikov <koct9i@gmail.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Shuah Khan <shuahkh@osg.samsung.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
8 years agoradix-tree tests: add iteration test
Ross Zwisler [Tue, 11 Oct 2016 20:51:21 +0000 (13:51 -0700)]
radix-tree tests: add iteration test

There are four cases I can see where we could end up with a NULL 'slot' in
radix_tree_next_slot().  This unit test exercises all four of them, making
sure that if in the future we have an unsafe path through
radix_tree_next_slot(), we'll catch it.

Here are details on the four cases:

1) radix_tree_iter_retry() via a non-tagged iteration like
radix_tree_for_each_slot().  In this case we currently aren't seeing a bug
because radix_tree_iter_retry() sets

    iter->next_index = iter->index;

which means that in in the else case in radix_tree_next_slot(), 'count' is
zero, so we skip over the while() loop and effectively just return NULL
without ever dereferencing 'slot'.

2) radix_tree_iter_retry() via tagged iteration like
radix_tree_for_each_tagged().  This case was giving us NULL pointer
dereferences in testing, and was fixed with this commit:

commit 3cb9185c6730 ("radix-tree: fix radix_tree_iter_retry() for tagged
iterators.")

This fix doesn't explicitly check for 'slot' being NULL, though, it works
around the NULL pointer dereference by instead zeroing iter->tags in
radix_tree_iter_retry(), which makes us bail out of the if() case in
radix_tree_next_slot() before we dereference 'slot'.

3) radix_tree_iter_next() via via a non-tagged iteration like
radix_tree_for_each_slot().  This currently happens in shmem_tag_pins()
and shmem_partial_swap_usage().

As with non-tagged iteration, 'count' in the else case of
radix_tree_next_slot() is zero, so we skip over the while() loop and
effectively just return NULL without ever dereferencing 'slot'.

4) radix_tree_iter_next() via tagged iteration like
radix_tree_for_each_tagged().  This happens in shmem_wait_for_pins().

radix_tree_iter_next() zeros out iter->tags, so we end up exiting
radix_tree_next_slot() here:

    if (flags & RADIX_TREE_ITER_TAGGED) {
    void *canon = slot;

    iter->tags >>= 1;
    if (unlikely(!iter->tags))
    return NULL;

Link: http://lkml.kernel.org/r/20160815194237.25967-3-ross.zwisler@linux.intel.com
Signed-off-by: Ross Zwisler <ross.zwisler@linux.intel.com>
Cc: Konstantin Khlebnikov <koct9i@gmail.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Shuah Khan <shuahkh@osg.samsung.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
8 years agoradix-tree: 'slot' can be NULL in radix_tree_next_slot()
Ross Zwisler [Tue, 11 Oct 2016 20:51:18 +0000 (13:51 -0700)]
radix-tree: 'slot' can be NULL in radix_tree_next_slot()

There are four cases I can see where we could end up with a NULL 'slot' in
radix_tree_next_slot().  Yet radix_tree_next_slot() never actually checks
whether 'slot' is NULL.  It just happens that for the cases where 'slot'
is NULL, some other combination of factors prevents us from dereferencing
it.

It would be very easy for someone to unwittingly change one of these
factors without realizing that we are implicitly depending on it to save
us from a NULL pointer dereference.

Add a comment documenting the things that allow 'slot' to be safely passed
as NULL to radix_tree_next_slot().

Here are details on the four cases:

1) radix_tree_iter_retry() via a non-tagged iteration like
radix_tree_for_each_slot().  In this case we currently aren't seeing a bug
because radix_tree_iter_retry() sets

iter->next_index = iter->index;

which means that in in the else case in radix_tree_next_slot(), 'count' is
zero, so we skip over the while() loop and effectively just return NULL
without ever dereferencing 'slot'.

2) radix_tree_iter_retry() via tagged iteration like
radix_tree_for_each_tagged().  This case was giving us NULL pointer
dereferences in testing, and was fixed with this commit:

commit 3cb9185c6730 ("radix-tree: fix radix_tree_iter_retry() for tagged
iterators.")

This fix doesn't explicitly check for 'slot' being NULL, though, it works
around the NULL pointer dereference by instead zeroing iter->tags in
radix_tree_iter_retry(), which makes us bail out of the if() case in
radix_tree_next_slot() before we dereference 'slot'.

3) radix_tree_iter_next() via via a non-tagged iteration like
radix_tree_for_each_slot().  This currently happens in shmem_tag_pins()
and shmem_partial_swap_usage().

As with non-tagged iteration, 'count' in the else case of
radix_tree_next_slot() is zero, so we skip over the while() loop and
effectively just return NULL without ever dereferencing 'slot'.

4) radix_tree_iter_next() via tagged iteration like
radix_tree_for_each_tagged().  This happens in shmem_wait_for_pins().

radix_tree_iter_next() zeros out iter->tags, so we end up exiting
radix_tree_next_slot() here:

if (flags & RADIX_TREE_ITER_TAGGED) {
void *canon = slot;

iter->tags >>= 1;
if (unlikely(!iter->tags))
return NULL;

Link: http://lkml.kernel.org/r/20160815194237.25967-2-ross.zwisler@linux.intel.com
Signed-off-by: Ross Zwisler <ross.zwisler@linux.intel.com>
Cc: Konstantin Khlebnikov <koct9i@gmail.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Shuah Khan <shuahkh@osg.samsung.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
8 years agofs/select: add vmalloc fallback for select(2)
Vlastimil Babka [Tue, 11 Oct 2016 20:51:14 +0000 (13:51 -0700)]
fs/select: add vmalloc fallback for select(2)

The select(2) syscall performs a kmalloc(size, GFP_KERNEL) where size grows
with the number of fds passed. We had a customer report page allocation
failures of order-4 for this allocation. This is a costly order, so it might
easily fail, as the VM expects such allocation to have a lower-order fallback.

Such trivial fallback is vmalloc(), as the memory doesn't have to be physically
contiguous and the allocation is temporary for the duration of the syscall
only. There were some concerns, whether this would have negative impact on the
system by exposing vmalloc() to userspace. Although an excessive use of vmalloc
can cause some system wide performance issues - TLB flushes etc. - a large
order allocation is not for free either and an excessive reclaim/compaction can
have a similar effect. Also note that the size is effectively limited by
RLIMIT_NOFILE which defaults to 1024 on the systems I checked. That means the
bitmaps will fit well within single page and thus the vmalloc() fallback could
be only excercised for processes where root allows a higher limit.

Note that the poll(2) syscall seems to use a linked list of order-0 pages, so
it doesn't need this kind of fallback.

[eric.dumazet@gmail.com: fix failure path logic]
[akpm@linux-foundation.org: use proper type for size]
Link: http://lkml.kernel.org/r/20160927084536.5923-1-vbabka@suse.cz
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Eric Dumazet <eric.dumazet@gmail.com>
Cc: David Laight <David.Laight@ACULAB.COM>
Cc: Hillf Danton <hillf.zj@alibaba-inc.com>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Jason Baron <jbaron@akamai.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
8 years agoblock: implement (some of) fallocate for block devices
Darrick J. Wong [Tue, 11 Oct 2016 20:51:11 +0000 (13:51 -0700)]
block: implement (some of) fallocate for block devices

After much discussion, it seems that the fallocate feature flag
FALLOC_FL_ZERO_RANGE maps nicely to SCSI WRITE SAME; and the feature
FALLOC_FL_PUNCH_HOLE maps nicely to the devices that have been whitelisted
for zeroing SCSI UNMAP.  Punch still requires that FALLOC_FL_KEEP_SIZE is
set.  A length that goes past the end of the device will be clamped to the
device size if KEEP_SIZE is set; or will return -EINVAL if not.  Both
start and length must be aligned to the device's logical block size.

Since the semantics of fallocate are fairly well established already, wire
up the two pieces.  The other fallocate variants (collapse range, insert
range, and allocate blocks) are not supported.

Link: http://lkml.kernel.org/r/147518379992.22791.8849838163218235007.stgit@birch.djwong.org
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Reviewed-by: Bart Van Assche <bart.vanassche@sandisk.com>
Cc: Theodore Ts'o <tytso@mit.edu>
Cc: Martin K. Petersen <martin.petersen@oracle.com>
Cc: Mike Snitzer <snitzer@redhat.com> # tweaked header
Cc: Brian Foster <bfoster@redhat.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Hannes Reinecke <hare@suse.de>
Cc: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
8 years agoblock: require write_same and discard requests align to logical block size
Darrick J. Wong [Tue, 11 Oct 2016 20:51:08 +0000 (13:51 -0700)]
block: require write_same and discard requests align to logical block size

Make sure that the offset and length arguments that we're using to
construct WRITE SAME and DISCARD requests are actually aligned to the
logical block size.  Failure to do this causes other errors in other parts
of the block layer or the SCSI layer because disks don't support partial
logical block writes.

Link: http://lkml.kernel.org/r/147518379026.22791.4437508871355153928.stgit@birch.djwong.org
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Bart Van Assche <bart.vanassche@sandisk.com>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Cc: Theodore Ts'o <tytso@mit.edu>
Cc: Mike Snitzer <snitzer@redhat.com> # tweaked header
Cc: Brian Foster <bfoster@redhat.com>
Cc: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
8 years agoblock: invalidate the page cache when issuing BLKZEROOUT
Darrick J. Wong [Tue, 11 Oct 2016 20:51:05 +0000 (13:51 -0700)]
block: invalidate the page cache when issuing BLKZEROOUT

Patch series "fallocate for block devices", v11.

This is a patchset to fix page cache coherency with BLKZEROOUT and
implement fallocate for block devices.

The first patch is a fix to the existing BLKZEROOUT ioctl to invalidate
the page cache if the zeroing command to the underlying device succeeds.
Without this patch we still have the pagecache coherence bug that's been
in the kernel forever.

The second patch changes the internal block device functions to reject
attempts to discard or zeroout that are not aligned to the logical block
size.  Previously, we only checked that the start/len parameters were
512-byte aligned, which caused kernel BUG_ONs for unaligned IOs to 4k-LBA
devices.

The third patch creates an fallocate handler for block devices, wires up
the FALLOC_FL_PUNCH_HOLE flag to zeroing-discard, and connects
FALLOC_FL_ZERO_RANGE to write-same so that we can have a consistent
fallocate interface between files and block devices.  It also allows the
combination of PUNCH_HOLE and NO_HIDE_STALE to invoke non-zeroing discard.

Test cases for the new block device fallocate are now in xfstests as
generic/349-351.

This patch (of 3):

Invalidate the page cache (as a regular O_DIRECT write would do) to avoid
returning stale cache contents at a later time.

Link: http://lkml.kernel.org/r/147518378313.22791.16649519283678515021.stgit@birch.djwong.org
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Reviewed-by: Bart Van Assche <bart.vanassche@sandisk.com>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Cc: Theodore Ts'o <tytso@mit.edu>
Cc: Mike Snitzer <snitzer@redhat.com>
Cc: Brian Foster <bfoster@redhat.com>
Cc: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
8 years agoocfs2: fix memory leak in dlm_migrate_request_handler()
Guozhonghua [Tue, 11 Oct 2016 20:51:01 +0000 (13:51 -0700)]
ocfs2: fix memory leak in dlm_migrate_request_handler()

In the dlm_migrate_request_handler(), when `ret' is -EEXIST, the mle
should be freed, otherwise the memory will be leaked.

Link: http://lkml.kernel.org/r/71604351584F6A4EBAE558C676F37CA4A3D3522A@H3CMLB12-EX.srv.huawei-3com.com
Signed-off-by: Guozhonghua <guozhonghua@h3c.com>
Reviewed-by: Mark Fasheh <mfasheh@versity.com>
Cc: Eric Ren <zren@suse.com>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Junxiao Bi <junxiao.bi@oracle.com>
Cc: Joseph Qi <joseph.qi@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
8 years agoFix off-by-one in __pipe_get_pages()
Al Viro [Tue, 11 Oct 2016 17:21:14 +0000 (18:21 +0100)]
Fix off-by-one in __pipe_get_pages()

it actually worked only when requested area ended on the page boundary...

Reported-by: Marco Grassi <marco.gra@gmail.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
8 years agoMerge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net
Linus Torvalds [Tue, 11 Oct 2016 15:10:19 +0000 (08:10 -0700)]
Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net

Pull networking fixes from David Miller:

 1) Netfilter list handling fix, from Linus.

 2) RXRPC/AFS bug fixes from David Howells (oops on call to serviceless
    endpoints, build warnings, missing notifications, etc.) From David
    Howells.

 3) Kernel log message missing newlines, from Colin Ian King.

 4) Don't enter direct reclaim in netlink dumps, the idea is to use a
    high order allocation first and fallback quickly to a 0-order
    allocation if such a high-order one cannot be done cheaply and
    without reclaim. From Eric Dumazet.

 5) Fix firmware download errors in btusb bluetooth driver, from Ethan
    Hsieh.

 6) Missing Kconfig deps for QCOM_EMAC, from Geert Uytterhoeven.

 7) Fix MDIO_XGENE dup Kconfig entry. From Laura Abbott.

 8) Constrain ipv6 rtr_solicits sysctl values properly, from Maciej
    Å»enczykowski.

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (65 commits)
  netfilter: Fix slab corruption.
  be2net: Enable VF link state setting for BE3
  be2net: Fix TX stats for TSO packets
  be2net: Update Copyright string in be_hw.h
  be2net: NCSI FW section should be properly updated with ethtool for BE3
  be2net: Provide an alternate way to read pf_num for BEx chips
  wan/fsl_ucc_hdlc: Fix size used in dma_free_coherent()
  net: macb: NULL out phydev after removing mdio bus
  xen-netback: make sure that hashes are not send to unaware frontends
  Fixing a bug in team driver due to incorrect 'unsigned int' to 'int' conversion
  MAINTAINERS: add myself as a maintainer of xen-netback
  ipv6 addrconf: disallow rtr_solicits < -1
  Bluetooth: btusb: Fix atheros firmware download error
  drivers: net: phy: Correct duplicate MDIO_XGENE entry
  ethernet: qualcomm: QCOM_EMAC should depend on HAS_DMA and HAS_IOMEM
  net: ethernet: mediatek: remove hwlro property in the device tree
  net: ethernet: mediatek: get hw lro capability by the chip id instead of by the dtsi
  net: ethernet: mediatek: get the chip id by ETHDMASYS registers
  net: bgmac: Fix errant feature flag check
  netlink: do not enter direct reclaim from netlink_dump()
  ...

8 years agonetfilter: Fix slab corruption.
Linus Torvalds [Tue, 11 Oct 2016 05:39:04 +0000 (22:39 -0700)]
netfilter: Fix slab corruption.

Use the correct pattern for singly linked list insertion and
deletion.  We can also calculate the list head outside of the
mutex.

Fixes: e3b37f11e6e4 ("netfilter: replace list_head with single linked list")
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Reviewed-by: Aaron Conole <aconole@bytheb.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
net/netfilter/core.c | 108 ++++++++++++++++-----------------------------------
 1 file changed, 33 insertions(+), 75 deletions(-)

8 years agoMerge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Linus Torvalds [Tue, 11 Oct 2016 03:16:43 +0000 (20:16 -0700)]
Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs

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

8 years agoMerge remote-tracking branch 'ovl/rename2' into for-linus
Al Viro [Tue, 11 Oct 2016 03:02:51 +0000 (23:02 -0400)]
Merge remote-tracking branch 'ovl/rename2' into for-linus

8 years agoMerge tag 'for-linus-20161008' of git://git.infradead.org/linux-mtd
Linus Torvalds [Tue, 11 Oct 2016 00:39:51 +0000 (17:39 -0700)]
Merge tag 'for-linus-20161008' of git://git.infradead.org/linux-mtd

Pull MTD updates from Brian Norris:
 "I've not been very active this cycle, so these are mostly from Boris,
  for the NAND flash subsystem.

  NAND:

   - Add the infrastructure to automate NAND timings configuration

   - Provide a generic DT property to maximize ECC strength

   - Some refactoring in the core bad block table handling, to help with
     improving some of the logic in error cases.

   - Minor cleanups and fixes

  MTD:

   - Add APIs for handling page pairing; this is necessary for reliably
     supporting MLC and TLC NAND flash, where paired-page disturbance
     affects reliability. Upper layers (e.g., UBI) should make use of
     these in the near future"

* tag 'for-linus-20161008' of git://git.infradead.org/linux-mtd: (35 commits)
  mtd: nand: fix trivial spelling error
  mtdpart: Propagate _get/put_device()
  mtd: nand: Provide nand_cleanup() function to free NAND related resources
  mtd: Kill the OF_MTD Kconfig option
  mtd: nand: mxc: Test CONFIG_OF instead of CONFIG_OF_MTD
  mtd: nand: Fix nand_command_lp() for 8bits opcodes
  mtd: nand: sunxi: Support ECC maximization
  mtd: nand: Support maximizing ECC when using software BCH
  mtd: nand: Add an option to maximize the ECC strength
  mtd: nand: mxc: Add timing setup for v2 controllers
  mtd: nand: mxc: implement onfi get/set features
  mtd: nand: sunxi: switch from manual to automated timing config
  mtd: nand: automate NAND timings selection
  mtd: nand: Expose data interface for ONFI mode 0
  mtd: nand: Add function to convert ONFI mode to data_interface
  mtd: nand: convert ONFI mode into data interface
  mtd: nand: Introduce nand_data_interface
  mtd: nand: Create a NAND reset function
  mtd: nand: remove unnecessary 'extern' from function declarations
  MAINTAINERS: Add maintainer entry for Ingenic JZ4780 NAND driver
  ...

8 years agoMerge branch 'work.xattr' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Linus Torvalds [Tue, 11 Oct 2016 00:11:50 +0000 (17:11 -0700)]
Merge branch 'work.xattr' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs

Pull vfs xattr updates from Al Viro:
 "xattr stuff from Andreas

  This completes the switch to xattr_handler ->get()/->set() from
  ->getxattr/->setxattr/->removexattr"

* 'work.xattr' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  vfs: Remove {get,set,remove}xattr inode operations
  xattr: Stop calling {get,set,remove}xattr inode operations
  vfs: Check for the IOP_XATTR flag in listxattr
  xattr: Add __vfs_{get,set,remove}xattr helpers
  libfs: Use IOP_XATTR flag for empty directory handling
  vfs: Use IOP_XATTR flag for bad-inode handling
  vfs: Add IOP_XATTR inode operations flag
  vfs: Move xattr_resolve_name to the front of fs/xattr.c
  ecryptfs: Switch to generic xattr handlers
  sockfs: Get rid of getxattr iop
  sockfs: getxattr: Fail with -EOPNOTSUPP for invalid attribute names
  kernfs: Switch to generic xattr handlers
  hfs: Switch to generic xattr handlers
  jffs2: Remove jffs2_{get,set,remove}xattr macros
  xattr: Remove unnecessary NULL attribute name check

8 years agoMerge branch 'linus' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6
Linus Torvalds [Mon, 10 Oct 2016 21:04:16 +0000 (14:04 -0700)]
Merge branch 'linus' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6

Pull crypto updates from Herbert Xu:
 "Here is the crypto update for 4.9:

  API:
   - The crypto engine code now supports hashes.

  Algorithms:
   - Allow keys >= 2048 bits in FIPS mode for RSA.

  Drivers:
   - Memory overwrite fix for vmx ghash.
   - Add support for building ARM sha1-neon in Thumb2 mode.
   - Reenable ARM ghash-ce code by adding import/export.
   - Reenable img-hash by adding import/export.
   - Add support for multiple cores in omap-aes.
   - Add little-endian support for sha1-powerpc.
   - Add Cavium HWRNG driver for ThunderX SoC"

* 'linus' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6: (137 commits)
  crypto: caam - treat SGT address pointer as u64
  crypto: ccp - Make syslog errors human-readable
  crypto: ccp - clean up data structure
  crypto: vmx - Ensure ghash-generic is enabled
  crypto: testmgr - add guard to dst buffer for ahash_export
  crypto: caam - Unmap region obtained by of_iomap
  crypto: sha1-powerpc - little-endian support
  crypto: gcm - Fix IV buffer size in crypto_gcm_setkey
  crypto: vmx - Fix memory corruption caused by p8_ghash
  crypto: ghash-generic - move common definitions to a new header file
  crypto: caam - fix sg dump
  hwrng: omap - Only fail if pm_runtime_get_sync returns < 0
  crypto: omap-sham - shrink the internal buffer size
  crypto: omap-sham - add support for export/import
  crypto: omap-sham - convert driver logic to use sgs for data xmit
  crypto: omap-sham - change the DMA threshold value to a define
  crypto: omap-sham - add support functions for sg based data handling
  crypto: omap-sham - rename sgl to sgl_tmp for deprecation
  crypto: omap-sham - align algorithms on word offset
  crypto: omap-sham - add context export/import stubs
  ...

8 years agoMerge tag 'dlm-4.9' of git://git.kernel.org/pub/scm/linux/kernel/git/teigland/linux-dlm
Linus Torvalds [Mon, 10 Oct 2016 20:58:06 +0000 (13:58 -0700)]
Merge tag 'dlm-4.9' of git://git.kernel.org/pub/scm/linux/kernel/git/teigland/linux-dlm

Pull dlm fix from David Teigland:
 "This includes a bug fix for a bad memory access during workqueue
  cleanup, which can happen while shutting down the dlm networking
  layer"

* tag 'dlm-4.9' of git://git.kernel.org/pub/scm/linux/kernel/git/teigland/linux-dlm:
  dlm: free workqueues after the connections

8 years agoMerge tag 'ceph-for-4.9-rc1' of git://github.com/ceph/ceph-client
Linus Torvalds [Mon, 10 Oct 2016 20:52:05 +0000 (13:52 -0700)]
Merge tag 'ceph-for-4.9-rc1' of git://github.com/ceph/ceph-client

Pull Ceph updates from Ilya Dryomov:
 "The big ticket item here is support for rbd exclusive-lock feature,
  with maintenance operations offloaded to userspace (Douglas Fuller,
  Mike Christie and myself). Another block device bullet is a series
  fixing up layering error paths (myself).

  On the filesystem side, we've got patches that improve our handling of
  buffered vs dio write races (Neil Brown) and a few assorted fixes from
  Zheng. Also included a couple of random cleanups and a minor CRUSH
  update"

* tag 'ceph-for-4.9-rc1' of git://github.com/ceph/ceph-client: (39 commits)
  crush: remove redundant local variable
  crush: don't normalize input of crush_ln iteratively
  libceph: ceph_build_auth() doesn't need ceph_auth_build_hello()
  libceph: use CEPH_AUTH_UNKNOWN in ceph_auth_build_hello()
  ceph: fix description for rsize and rasize mount options
  rbd: use kmalloc_array() in rbd_header_from_disk()
  ceph: use list_move instead of list_del/list_add
  ceph: handle CEPH_SESSION_REJECT message
  ceph: avoid accessing / when mounting a subpath
  ceph: fix mandatory flock check
  ceph: remove warning when ceph_releasepage() is called on dirty page
  ceph: ignore error from invalidate_inode_pages2_range() in direct write
  ceph: fix error handling of start_read()
  rbd: add rbd_obj_request_error() helper
  rbd: img_data requests don't own their page array
  rbd: don't call rbd_osd_req_format_read() for !img_data requests
  rbd: rework rbd_img_obj_exists_submit() error paths
  rbd: don't crash or leak on errors in rbd_img_obj_parent_read_full_callback()
  rbd: move bumping img_request refcount into rbd_obj_request_submit()
  rbd: mark the original request as done if stat request fails
  ...

8 years agoMerge branch 'work.splice_read' of git://git.kernel.org/pub/scm/linux/kernel/git...
Linus Torvalds [Mon, 10 Oct 2016 20:38:49 +0000 (13:38 -0700)]
Merge branch 'work.splice_read' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs

Pull splice fixups from Al Viro:
 "A couple of fixups for interaction of pipe-backed iov_iter with
  O_DIRECT reads + constification of a couple of primitives in uio.h
  missed by previous rounds.

  Kudos to davej - his fuzzing has caught those bugs"

* 'work.splice_read' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  [btrfs] fix check_direct_IO() for non-iovec iterators
  constify iov_iter_count() and iter_is_iovec()
  fix ITER_PIPE interaction with direct_IO

8 years agoMerge branch 'work.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Linus Torvalds [Mon, 10 Oct 2016 20:04:49 +0000 (13:04 -0700)]
Merge branch 'work.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs

Pull misc vfs updates from Al Viro:
 "Assorted misc bits and pieces.

  There are several single-topic branches left after this (rename2
  series from Miklos, current_time series from Deepa Dinamani, xattr
  series from Andreas, uaccess stuff from from me) and I'd prefer to
  send those separately"

* 'work.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (39 commits)
  proc: switch auxv to use of __mem_open()
  hpfs: support FIEMAP
  cifs: get rid of unused arguments of CIFSSMBWrite()
  posix_acl: uapi header split
  posix_acl: xattr representation cleanups
  fs/aio.c: eliminate redundant loads in put_aio_ring_file
  fs/internal.h: add const to ns_dentry_operations declaration
  compat: remove compat_printk()
  fs/buffer.c: make __getblk_slow() static
  proc: unsigned file descriptors
  fs/file: more unsigned file descriptors
  fs: compat: remove redundant check of nr_segs
  cachefiles: Fix attempt to read i_blocks after deleting file [ver #2]
  cifs: don't use memcpy() to copy struct iov_iter
  get rid of separate multipage fault-in primitives
  fs: Avoid premature clearing of capabilities
  fs: Give dentry to inode_change_ok() instead of inode
  fuse: Propagate dentry down to inode_change_ok()
  ceph: Propagate dentry down to inode_change_ok()
  xfs: Propagate dentry down to inode_change_ok()
  ...

8 years agoMerge branch 'pcmcia' of git://git.armlinux.org.uk/~rmk/linux-arm
Linus Torvalds [Mon, 10 Oct 2016 18:34:28 +0000 (11:34 -0700)]
Merge branch 'pcmcia' of git://git.armlinux.org.uk/~rmk/linux-arm

Pull ARM pcmcia updates from Russell King:
 "These updates lay the foundations for more generic soc_common PCMCIA
  support, which will result in several of the board specific drivers
  being elimated.

  As the dependencies for this are complex, the preliminary work is
  being submitted now, with the remainder scheduled for the next merge
  window"

* 'pcmcia' of git://git.armlinux.org.uk/~rmk/linux-arm:
  pcmcia: soc_common: add driver-data pointer
  pcmcia: soc_common: add support for voltage sense GPIOs
  pcmcia: soc_common: constify pcmcia_low_level ops pointer
  pcmcia: soc_common: switch to a per-socket cpufreq notifier
  pcmcia: soc_common: add support for Vcc and Vpp regulators
  pcmcia: soc_common: add CF socket state helper
  pcmcia: soc_common: restore previous socket state on error
  pcmcia: soc_common: add support for reset and bus enable GPIOs
  pcmcia: soc_common: request legacy detect GPIO with active low
  pcmcia: soc_common: ignore invalid interrupts
  pcmcia: soc_common: switch to using gpio_descs
  pcmcia: soc_common: use devm_gpio_request_one()

8 years agoMerge tag 'nios2-v4.9-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/lftan...
Linus Torvalds [Mon, 10 Oct 2016 18:31:19 +0000 (11:31 -0700)]
Merge tag 'nios2-v4.9-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/lftan/nios2

Pull nios2 update from Ley Foon Tan:
 "Use of_property_read_bool() instead of open-coding it"

* tag 'nios2-v4.9-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/lftan/nios2:
  nios2: use of_property_read_bool

8 years agoMerge tag 'cris-for-4.9' of git://git.kernel.org/pub/scm/linux/kernel/git/jesper...
Linus Torvalds [Mon, 10 Oct 2016 18:28:35 +0000 (11:28 -0700)]
Merge tag 'cris-for-4.9' of git://git.kernel.org/pub/scm/linux/kernel/git/jesper/cris

Pull CRIS updates from Jesper Nilsson.

* tag 'cris-for-4.9' of git://git.kernel.org/pub/scm/linux/kernel/git/jesper/cris:
  cris: return of class_create should be considered
  CRIS: defconfig: remove MTDRAM_ABS_POS
  CRIS v32: remove some double unlocks
  Fix typos
  cris: migrate exception table users off module.h and onto extable.h
  cris: v10: axisflashmap: remove unused ifdefs
  cris: use generic io.h
  cris: fix Kconfig mismatch when building with CONFIG_PCI
  cris: cardbus: fix header include path
  cris: add dev88_defconfig
  cris: irq: stop loop from accessing array out of bounds
  cris: fasttimer: fix mixed declarations and code compile warning
  cris: intmem: fix pointer comparison compile warning
  cris: intmem: fix device_initcall compile warning

8 years agoMerge branch 'mm-pkeys-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git...
Linus Torvalds [Mon, 10 Oct 2016 18:01:51 +0000 (11:01 -0700)]
Merge branch 'mm-pkeys-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull protection keys syscall interface from Thomas Gleixner:
 "This is the final step of Protection Keys support which adds the
  syscalls so user space can actually allocate keys and protect memory
  areas with them. Details and usage examples can be found in the
  documentation.

  The mm side of this has been acked by Mel"

* 'mm-pkeys-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/pkeys: Update documentation
  x86/mm/pkeys: Do not skip PKRU register if debug registers are not used
  x86/pkeys: Fix pkeys build breakage for some non-x86 arches
  x86/pkeys: Add self-tests
  x86/pkeys: Allow configuration of init_pkru
  x86/pkeys: Default to a restrictive init PKRU
  pkeys: Add details of system call use to Documentation/
  generic syscalls: Wire up memory protection keys syscalls
  x86: Wire up protection keys system calls
  x86/pkeys: Allocation/free syscalls
  x86/pkeys: Make mprotect_key() mask off additional vm_flags
  mm: Implement new pkey_mprotect() system call
  x86/pkeys: Add fault handling for PF_PK page fault bit

8 years agoMerge branch 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel...
Linus Torvalds [Mon, 10 Oct 2016 17:59:07 +0000 (10:59 -0700)]
Merge branch 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull x86 updates from Thomas Gleixner:
 "A pile of regression fixes and updates:

   - address the fallout of the patches which made the cpuid - nodeid
     relation permanent: Handling of invalid APIC ids and preventing
     pointless warning messages.

   - force eager FPU when protection keys are enabled. Protection keys
     are not generating FPU exceptions so they cannot work with the lazy
     FPU mechanism.

   - prevent force migration of interrupts which are not part of the CPU
     vector domain.

   - handle the fact that APIC ids are not updated in the ACPI/MADT
     tables on physical CPU hotplug

   - remove bash-isms from syscall table generator script

   - use the hypervisor supplied APIC frequency when running on VMware"

* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/pkeys: Make protection keys an "eager" feature
  x86/apic: Prevent pointless warning messages
  x86/acpi: Prevent LAPIC id 0xff from being accounted
  arch/x86: Handle non enumerated CPU after physical hotplug
  x86/unwind: Fix oprofile module link error
  x86/vmware: Skip lapic calibration on VMware
  x86/syscalls: Remove bash-isms in syscall table generator
  x86/irq: Prevent force migration of irqs which are not in the vector domain

8 years ago[btrfs] fix check_direct_IO() for non-iovec iterators
Al Viro [Mon, 10 Oct 2016 17:39:05 +0000 (13:39 -0400)]
[btrfs] fix check_direct_IO() for non-iovec iterators

looking for duplicate ->iov_base makes sense only for
iovec-backed iterators; for kvec-backed ones it's pointless,
for bvec-backed ones it's pointless and broken on 32bit (we
walk through an array of struct bio_vec accessing them as if
they were struct iovec; works by accident on 64bit, but on
32bit it'll blow up) and for pipe-backed ones it's pointless
and ends up oopsing.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
8 years agoconstify iov_iter_count() and iter_is_iovec()
Al Viro [Mon, 10 Oct 2016 17:57:37 +0000 (13:57 -0400)]
constify iov_iter_count() and iter_is_iovec()

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
8 years agofix ITER_PIPE interaction with direct_IO
Al Viro [Mon, 10 Oct 2016 17:26:27 +0000 (13:26 -0400)]
fix ITER_PIPE interaction with direct_IO

by making sure we call iov_iter_advance() on original
iov_iter even if direct_IO (done on its copy) has returned 0.
It's a no-op for old iov_iter flavours and does the right thing
(== truncation of the stuff we'd allocated, but not filled) in
ITER_PIPE case.  Failures (e.g. -EIO) get caught and dealt with
by cleanup in generic_file_read_iter().

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
8 years agoMerge branch 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel...
Linus Torvalds [Mon, 10 Oct 2016 17:33:58 +0000 (10:33 -0700)]
Merge branch 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull perf tooling updates from Thomas Gleixner:

 - handle uretprobe placement proper on little endian PPC64

 - fix buffer handling in libtraceevent

 - add a missing pointer derefence in perf probe

 - fix the build of host tools in cross builds

 - fix Intel PT timestamp handling

 - synchronize memcpy, cpufeatures and bpf headers with the kernel headers

 - support for vendor supplied JSON files describing PMU events

 - a new set of tool tips

 - initial work for clang/llvm support

 - address some style issues found by cppcheck

* 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (35 commits)
  tools build: Add feature detection for g++
  tools build: Support compiling C++ source file
  perf top/report: Add tips about a list option
  perf report/top: Add a tip about system-wide collection from all CPUs
  perf report/top: Add a tip about source line numbers with overhead
  tools: Synchronize tools/include/uapi/linux/bpf.h
  tools: Synchronize tools/arch/x86/include/asm/cpufeatures.h
  perf bench mem: Sync memcpy assembly sources with the kernel
  perf jevents: Fix Intel JSON fixed counter conversions
  tools lib traceevent: Fix kbuffer_read_at_offset()
  perf intel-pt: Fix MTC timestamp calculation for large MTC periods
  perf intel-pt: Fix estimated timestamps for cycle-accurate mode
  perf uretprobe ppc64le: Fix probe location
  perf pmu-events: Add Skylake frontend MSR support
  perf pmu-events: Fix fixed counters on Intel
  perf tools: Make alias matching case-insensitive
  perf tools: Allow period= in perf stat CPU event descriptions.
  perf tools: Add README for info on parsing JSON/map files
  perf list jevents: Add support for event list topics
  perf list: Support long jevents descriptions
  ...

8 years agoMerge branch 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel...
Linus Torvalds [Mon, 10 Oct 2016 17:29:59 +0000 (10:29 -0700)]
Merge branch 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull scheduler fix from Thomas Gleixner:
 "A revert of a commit which pointelessly widened a preempt disabled
  section which in turn caused might_sleep() to trigger.

  The patch intended to prevent usage of smp_processor_id() in
  preemptible context, but the usage in that case is fine because the
  thread is pinned on a single cpu and therefore cannot be migrated off"

* 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  Revert "sched/core: Do not use smp_processor_id() with preempt enabled in smpboot_thread_fn()"

8 years agoMerge branch 'irq-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel...
Linus Torvalds [Mon, 10 Oct 2016 17:24:41 +0000 (10:24 -0700)]
Merge branch 'irq-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull irq fixes from Thomas Gleixner:
 "Two small kerneldoc fixes from Julia Lawall"

* 'irq-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  irqchip/metag-ext: Improve function-level documentation
  irqchip/vic: Improve function-level documentation

8 years agoMerge branch 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel...
Linus Torvalds [Mon, 10 Oct 2016 17:23:18 +0000 (10:23 -0700)]
Merge branch 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull timer fix from Thomas Gleixner:
 "A single fix for a regression introduced in 4.8 which causes the
  trace/perf clock to return random nonsense if CONFIG_DEBUG_TIMEKEEPING
  is set"

* 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  timekeeping: Fix __ktime_get_fast_ns() regression

8 years agoMerge branch 'printk-cleanups'
Linus Torvalds [Mon, 10 Oct 2016 16:29:50 +0000 (09:29 -0700)]
Merge branch 'printk-cleanups'

Merge my system logging cleanups, triggered by the broken '\n' patches.

The line continuation handling has been broken basically forever, and
the code to handle the system log records was both confusing and
dubious.  And it would do entirely the wrong thing unless you always had
a terminating newline, partly because it couldn't actually see whether a
message was marked KERN_CONT or not (but partly because the LOG_CONT
handling in the recording code was rather confusing too).

This re-introduces a real semantically meaningful KERN_CONT, and fixes
the few places I noticed where it was missing.  There are probably more
missing cases, since KERN_CONT hasn't actually had any semantic meaning
for at least four years (other than the checkpatch meaning of "no log
level necessary, this is a continuation line").

This also allows the combination of KERN_CONT and a log level.  In that
case the log level will be ignored if the merging with a previous line
is successful, but if a new record is needed, that new record will now
get the right log level.

That also means that you can at least in theory combine KERN_CONT with
the "pr_info()" style helpers, although any use of pr_fmt() prefixing
would make that just result in a mess, of course (the prefix would end
up in the middle of a continuing line).

* printk-cleanups:
  printk: make reading the kernel log flush pending lines
  printk: re-organize log_output() to be more legible
  printk: split out core logging code into helper function
  printk: reinstate KERN_CONT for printing continuation lines

8 years agodlm: free workqueues after the connections
Marcelo Ricardo Leitner [Sat, 8 Oct 2016 13:14:37 +0000 (10:14 -0300)]
dlm: free workqueues after the connections

After backporting commit ee44b4bc054a ("dlm: use sctp 1-to-1 API")
series to a kernel with an older workqueue which didn't use RCU yet, it
was noticed that we are freeing the workqueues in dlm_lowcomms_stop()
too early as free_conn() will try to access that memory for canceling
the queued works if any.

This issue was introduced by commit 0d737a8cfd83 as before it such
attempt to cancel the queued works wasn't performed, so the issue was
not present.

This patch fixes it by simply inverting the free order.

Cc: stable@vger.kernel.org
Fixes: 0d737a8cfd83 ("dlm: fix race while closing connections")
Signed-off-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Signed-off-by: David Teigland <teigland@redhat.com>
8 years agoMerge git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6
Herbert Xu [Mon, 10 Oct 2016 03:19:47 +0000 (11:19 +0800)]
Merge git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6

Merge the crypto tree to pull in vmx ghash fix.

8 years agoMerge branch 'for-4.9/block-smp' of git://git.kernel.dk/linux-block
Linus Torvalds [Mon, 10 Oct 2016 00:32:20 +0000 (17:32 -0700)]
Merge branch 'for-4.9/block-smp' of git://git.kernel.dk/linux-block

Pull blk-mq CPU hotplug update from Jens Axboe:
 "This is the conversion of blk-mq to the new hotplug state machine"

* 'for-4.9/block-smp' of git://git.kernel.dk/linux-block:
  blk-mq: fixup "Convert to new hotplug state machine"
  blk-mq: Convert to new hotplug state machine
  blk-mq/cpu-notif: Convert to new hotplug state machine

8 years agoMerge branch 'for-4.9/block-irq' of git://git.kernel.dk/linux-block
Linus Torvalds [Mon, 10 Oct 2016 00:29:33 +0000 (17:29 -0700)]
Merge branch 'for-4.9/block-irq' of git://git.kernel.dk/linux-block

Pull blk-mq irq/cpu mapping updates from Jens Axboe:
 "This is the block-irq topic branch for 4.9-rc. It's mostly from
  Christoph, and it allows drivers to specify their own mappings, and
  more importantly, to share the blk-mq mappings with the IRQ affinity
  mappings. It's a good step towards making this work better out of the
  box"

* 'for-4.9/block-irq' of git://git.kernel.dk/linux-block:
  blk_mq: linux/blk-mq.h does not include all the headers it depends on
  blk-mq: kill unused blk_mq_create_mq_map()
  blk-mq: get rid of the cpumask in struct blk_mq_tags
  nvme: remove the post_scan callout
  nvme: switch to use pci_alloc_irq_vectors
  blk-mq: provide a default queue mapping for PCI device
  blk-mq: allow the driver to pass in a queue mapping
  blk-mq: remove ->map_queue
  blk-mq: only allocate a single mq_map per tag_set
  blk-mq: don't redistribute hardware queues on a CPU hotplug event

8 years agoMerge tag 'dm-4.9-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/device...
Linus Torvalds [Mon, 10 Oct 2016 00:16:18 +0000 (17:16 -0700)]
Merge tag 'dm-4.9-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm

Pull device mapper updates from Mike Snitzer:

 - various fixes and cleanups for request-based DM core

 - add support for delaying the requeue of requests; used by DM
   multipath when all paths have failed and 'queue_if_no_path' is
   enabled

 - DM cache improvements to speedup the loading metadata and the writing
   of the hint array

 - fix potential for a dm-crypt crash on device teardown

 - remove dm_bufio_cond_resched() and just using cond_resched()

 - change DM multipath to return a reservation conflict error
   immediately; rather than failing the path and retrying (potentially
   indefinitely)

* tag 'dm-4.9-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm: (24 commits)
  dm mpath: always return reservation conflict without failing over
  dm bufio: remove dm_bufio_cond_resched()
  dm crypt: fix crash on exit
  dm cache metadata: switch to using the new cursor api for loading metadata
  dm array: introduce cursor api
  dm btree: introduce cursor api
  dm cache policy smq: distribute entries to random levels when switching to smq
  dm cache: speed up writing of the hint array
  dm array: add dm_array_new()
  dm mpath: delay the requeue of blk-mq requests while all paths down
  dm mpath: use dm_mq_kick_requeue_list()
  dm rq: introduce dm_mq_kick_requeue_list()
  dm rq: reduce arguments passed to map_request() and dm_requeue_original_request()
  dm rq: add DM_MAPIO_DELAY_REQUEUE to delay requeue of blk-mq requests
  dm: convert wait loops to use autoremove_wake_function()
  dm: use signal_pending_state() in dm_wait_for_completion()
  dm: rename task state function arguments
  dm: add two lockdep_assert_held() statements
  dm rq: simplify dm_old_stop_queue()
  dm mpath: check if path's request_queue is dying in activate_path()
  ...

8 years agoMerge tag 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dledford/rdma
Linus Torvalds [Mon, 10 Oct 2016 00:04:33 +0000 (17:04 -0700)]
Merge tag 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dledford/rdma

Pull main rdma updates from Doug Ledford:
 "This is the main pull request for the rdma stack this release.  The
  code has been through 0day and I had it tagged for linux-next testing
  for a couple days.

  Summary:

   - updates to mlx5

   - updates to mlx4 (two conflicts, both minor and easily resolved)

   - updates to iw_cxgb4 (one conflict, not so obvious to resolve,
     proper resolution is to keep the code in cxgb4_main.c as it is in
     Linus' tree as attach_uld was refactored and moved into
     cxgb4_uld.c)

   - improvements to uAPI (moved vendor specific API elements to uAPI
     area)

   - add hns-roce driver and hns and hns-roce ACPI reset support

   - conversion of all rdma code away from deprecated
     create_singlethread_workqueue

   - security improvement: remove unsafe ib_get_dma_mr (breaks lustre in
     staging)"

* tag 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dledford/rdma: (75 commits)
  staging/lustre: Disable InfiniBand support
  iw_cxgb4: add fast-path for small REG_MR operations
  cxgb4: advertise support for FR_NSMR_TPTE_WR
  IB/core: correctly handle rdma_rw_init_mrs() failure
  IB/srp: Fix infinite loop when FMR sg[0].offset != 0
  IB/srp: Remove an unused argument
  IB/core: Improve ib_map_mr_sg() documentation
  IB/mlx4: Fix possible vl/sl field mismatch in LRH header in QP1 packets
  IB/mthca: Move user vendor structures
  IB/nes: Move user vendor structures
  IB/ocrdma: Move user vendor structures
  IB/mlx4: Move user vendor structures
  IB/cxgb4: Move user vendor structures
  IB/cxgb3: Move user vendor structures
  IB/mlx5: Move and decouple user vendor structures
  IB/{core,hw}: Add constant for node_desc
  ipoib: Make ipoib_warn ratelimited
  IB/mlx4/alias_GUID: Remove deprecated create_singlethread_workqueue
  IB/ipoib_verbs: Remove deprecated create_singlethread_workqueue
  IB/ipoib: Remove deprecated create_singlethread_workqueue
  ...

8 years agoMerge tag 'for-linus-2' of git://git.kernel.org/pub/scm/linux/kernel/git/dledford...
Linus Torvalds [Sun, 9 Oct 2016 23:30:03 +0000 (16:30 -0700)]
Merge tag 'for-linus-2' of git://git.kernel.org/pub/scm/linux/kernel/git/dledford/rdma

Pull more rdma updates from Doug Ledford:
 "Minor updates for rxe driver"

[ Starting to do merge window pulls again - the current -git tree does
  appear to have some netfilter use-after-free issues, but I've sent
  off the report to the proper channels, and I don't want to delay merge
  window activity any more ]

* tag 'for-linus-2' of git://git.kernel.org/pub/scm/linux/kernel/git/dledford/rdma:
  IB/rxe: improved debug prints & code cleanup
  rdma_rxe: Ensure rdma_rxe init occurs at correct time
  IB/rxe: Properly honor max IRD value for rd/atomic.
  IB/{rxe,core,rdmavt}: Fix kernel crash for reg MR
  IB/rxe: Fix sending out loopback packet on netdev interface.
  IB/rxe: Avoid scheduling tasklet for userspace QP

8 years agoprintk: make reading the kernel log flush pending lines
Linus Torvalds [Sun, 9 Oct 2016 19:16:57 +0000 (12:16 -0700)]
printk: make reading the kernel log flush pending lines

That will mean that any possible subsequent continuation will now be
broken up onto a line of its own (since reading the log has finalized
the beginning og the line), but if user space has activated system
logging (or if there's a kernel message dump going on) that is the right
thing to do.

And now that we actually get the continuation flags _right_ for this
all, the user space logger that is reading the kernel messages can
actually see the continuation marker.  Not that anybody seems to really
bother with it (or care), but in theory user space can do its own
message stitching.

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
8 years agoprintk: re-organize log_output() to be more legible
Linus Torvalds [Sun, 9 Oct 2016 18:53:00 +0000 (11:53 -0700)]
printk: re-organize log_output() to be more legible

Avoid some duplicate logic now that we can return early, and update the
comments for the new LOG_CONT world order.

This also stops the continuation flushing from just using random record
flags for the flushing action, instead taking the flags from the proper
original line and updating them as we add continuations to it.

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
8 years agoprintk: split out core logging code into helper function
Linus Torvalds [Sun, 9 Oct 2016 05:02:09 +0000 (22:02 -0700)]
printk: split out core logging code into helper function

The code that actually decides how to log the message (whether to put it
directly into the record log, whether to append it to an existing
buffered log, or whether to start a new buffered log) is fairly
non-obvious code in the middle of the vprintk_emit() function.

Splitting that code up into a helper function makes it easier to
understand, but perhaps more importantly also allows for the code to
just return early out of the helper function once it has made the
decision about where the new log content goes.

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>