Davidlohr Bueso [Tue, 11 Oct 2016 20:54:56 +0000 (13:54 -0700)]
ipc/msg: batch queue sender wakeups
Currently the use of wake_qs in sysv msg queues are only for the receiver
tasks that are blocked on the queue. But blocked sender tasks (due to
queue size constraints) still are awoken with the ipc object lock held,
which can be a problem particularly for small sized queues and far from
gracious for -rt (just like it was for the receiver side).
The paths that actually wakeup a sender are obviously related to when we
are either getting rid of the queue or after (some) space is freed-up
after a receiver takes the msg (msgrcv). Furthermore, with the exception
of msgrcv, we can always piggy-back on expunge_all that has its own tasks
lined-up for waking. Finally, upon unlinking the message, it should be no
problem delaying the wakeups a bit until after we've released the lock.
Link: http://lkml.kernel.org/r/1469748819-19484-3-git-send-email-dave@stgolabs.net Signed-off-by: Davidlohr Bueso <dbueso@suse.de> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Manfred Spraul <manfred@colorfullife.com> Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This patch moves the wakeup_process() invocation so it is not done under
the ipc global lock by making use of a lockless wake_q. With this change,
the waiter is woken up once the message has been assigned and it does not
need to loop on SMP if the message points to NULL. In the signal case we
still need to check the pointer under the lock to verify the state.
This change should also avoid the introduction of preempt_disable() in -RT
which avoids a busy-loop which pools for the NULL -> !NULL change if the
waiter has a higher priority compared to the waker.
By making use of wake_qs, the logic of sysv msg queues is greatly
simplified (and very well suited as we can batch lockless wakeups),
particularly around the lockless receive algorithm.
This has been tested with Manred's pmsg-shared tool on a "AMD A10-7800
Radeon R7, 12 Compute Cores 4C+8G":
Manfred Spraul [Tue, 11 Oct 2016 20:54:50 +0000 (13:54 -0700)]
ipc/sem.c: fix complex_count vs. simple op race
Commit 6d07b68ce16a ("ipc/sem.c: optimize sem_lock()") introduced a
race:
sem_lock has a fast path that allows parallel simple operations.
There are two reasons why a simple operation cannot run in parallel:
- a non-simple operations is ongoing (sma->sem_perm.lock held)
- a complex operation is sleeping (sma->complex_count != 0)
As both facts are stored independently, a thread can bypass the current
checks by sleeping in the right positions. See below for more details
(or kernel bugzilla 105651).
The patch fixes that by creating one variable (complex_mode)
that tracks both reasons why parallel operations are not possible.
The patch also updates stale documentation regarding the locking.
With regards to stable kernels:
The patch is required for all kernels that include the
commit 6d07b68ce16a ("ipc/sem.c: optimize sem_lock()") (3.10?)
The alternative is to revert the patch that introduced the race.
The patch is safe for backporting, i.e. it makes no assumptions
about memory barriers in spin_unlock_wait().
Background:
Here is the race of the current implementation:
Thread A: (simple op)
- does the first "sma->complex_count == 0" test
Thread B: (complex op)
- does sem_lock(): This includes an array scan. But the scan can't
find Thread A, because Thread A does not own sem->lock yet.
- the thread does the operation, increases complex_count,
drops sem_lock, sleeps
Thread A:
- spin_lock(&sem->lock), spin_is_locked(sma->sem_perm.lock)
- sleeps before the complex_count test
Thread C: (complex op)
- does sem_lock (no array scan, complex_count==1)
- wakes up Thread B.
- decrements complex_count
Thread A:
- does the complex_count test
Bug:
Now both thread A and thread C operate on the same array, without
any synchronization.
There's no point in collecting coverage from lib/stackdepot.c, as it is
not a function of syscall inputs. Disabling kcov instrumentation for that
file will reduce the coverage noise level.
Rob Herring [Tue, 11 Oct 2016 20:54:38 +0000 (13:54 -0700)]
config: android: move device mapper options to recommended
CONFIG_MD is in recommended, but other dependent options like DM_CRYPT and
DM_VERITY options are in base. The result is the options in base don't
get enabled when applying both base and recommended fragments. Move all
the options to recommended.
Link: http://lkml.kernel.org/r/20160908185934.18098-1-robh@kernel.org Signed-off-by: Rob Herring <robh@kernel.org> Acked-by: John Stultz <john.stultz@linaro.org> Cc: Amit Pundir <amit.pundir@linaro.org> Cc: Dmitry Shmidt <dimitrysh@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Peter Zijlstra [Tue, 11 Oct 2016 20:54:33 +0000 (13:54 -0700)]
relay: Use irq_work instead of plain timer for deferred wakeup
Relay avoids calling wake_up_interruptible() for doing the wakeup of
readers/consumers, waiting for the generation of new data, from the
context of a process which produced the data. This is apparently done to
prevent the possibility of a deadlock in case Scheduler itself is is
generating data for the relay, after acquiring rq->lock.
The following patch used a timer (to be scheduled at next jiffy), for
delegating the wakeup to another context.
commit 7c9cb38302e78d24e37f7d8a2ea7eed4ae5f2fa7
Author: Tom Zanussi <zanussi@comcast.net>
Date: Wed May 9 02:34:01 2007 -0700
relay: use plain timer instead of delayed work
relay doesn't need to use schedule_delayed_work() for waking readers
when a simple timer will do.
Scheduling a plain timer, at next jiffies boundary, to do the wakeup
causes a significant wakeup latency for the Userspace client, which makes
relay less suitable for the high-frequency low-payload use cases where the
data gets generated at a very high rate, like multiple sub buffers getting
filled within a milli second. Moreover the timer is re-scheduled on every
newly produced sub buffer so the timer keeps getting pushed out if sub
buffers are filled in a very quick succession (less than a jiffy gap
between filling of 2 sub buffers). As a result relay runs out of sub
buffers to store the new data.
By using irq_work it is ensured that wakeup of userspace client, blocked
in the poll call, is done at earliest (through self IPI or next timer
tick) enabling it to always consume the data in time. Also this makes
relay consistent with printk & ring buffers (trace), as they too use
irq_work for deferred wake up of readers.
[arnd@arndb.de: select CONFIG_IRQ_WORK] Link: http://lkml.kernel.org/r/20160912154035.3222156-1-arnd@arndb.de
[akpm@linux-foundation.org: coding-style fixes] Link: http://lkml.kernel.org/r/1472906487-1559-1-git-send-email-akash.goel@intel.com Signed-off-by: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Akash Goel <akash.goel@intel.com> Cc: Tom Zanussi <tzanussi@gmail.com> Cc: Chris Wilson <chris@chris-wilson.co.uk> Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com> Signed-off-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
pps: kc: fix non-tickless system config dependency
CONFIG_NO_HZ currently only sets the default value of dynticks config so
if PPS kernel consumer needs periodic timer ticks it should depend on
!CONFIG_NO_HZ_COMMON instead of !CONFIG_NO_HZ.
Otherwise it is possible to enable it even on tickless system which has
CONFIG_NO_HZ not set and CONFIG_NO_HZ_IDLE (or CONFIG_NO_HZ_FULL) set.
Link: http://lkml.kernel.org/r/57E2B769.50202@maciej.szmigiero.name Signed-off-by: Maciej S. Szmigiero <mail@maciej.szmigiero.name> Acked-by: Rodolfo Giometti <giometti@enneenne.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Hidehiro Kawai [Tue, 11 Oct 2016 20:54:26 +0000 (13:54 -0700)]
mips/panic: replace smp_send_stop() with kdump friendly version in panic path
Daniel Walker reported problems which happens when
crash_kexec_post_notifiers kernel option is enabled
(https://lkml.org/lkml/2015/6/24/44).
In that case, smp_send_stop() is called before entering kdump routines
which assume other CPUs are still online. As the result, kdump
routines fail to save other CPUs' registers. Additionally for MIPS
OCTEON, it misses to stop the watchdog timer.
To fix this problem, call a new kdump friendly function,
crash_smp_send_stop(), instead of the smp_send_stop() when
crash_kexec_post_notifiers is enabled. crash_smp_send_stop() is a
weak function, and it just call smp_send_stop(). Architecture
codes should override it so that kdump can work appropriately.
This patch provides MIPS version.
Fixes: f06e5153f4ae (kernel/panic.c: add "crash_kexec_post_notifiers" option) Link: http://lkml.kernel.org/r/20160810080950.11028.28000.stgit@sysi4-13.yrl.intra.hitachi.co.jp Signed-off-by: Hidehiro Kawai <hidehiro.kawai.ez@hitachi.com> Reported-by: Daniel Walker <dwalker@fifo99.com> Cc: Dave Young <dyoung@redhat.com> Cc: Baoquan He <bhe@redhat.com> Cc: Vivek Goyal <vgoyal@redhat.com> Cc: Eric Biederman <ebiederm@xmission.com> Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Daniel Walker <dwalker@fifo99.com> Cc: Xunlei Pang <xpang@redhat.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Borislav Petkov <bp@suse.de> Cc: David Vrabel <david.vrabel@citrix.com> Cc: Toshi Kani <toshi.kani@hpe.com> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: David Daney <david.daney@cavium.com> Cc: Aaro Koskinen <aaro.koskinen@iki.fi> Cc: "Steven J. Hill" <steven.hill@cavium.com> Cc: Corey Minyard <cminyard@mvista.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Hidehiro Kawai [Tue, 11 Oct 2016 20:54:23 +0000 (13:54 -0700)]
x86/panic: replace smp_send_stop() with kdump friendly version in panic path
Daniel Walker reported problems which happens when
crash_kexec_post_notifiers kernel option is enabled
(https://lkml.org/lkml/2015/6/24/44).
In that case, smp_send_stop() is called before entering kdump routines
which assume other CPUs are still online. As the result, for x86, kdump
routines fail to save other CPUs' registers and disable virtualization
extensions.
To fix this problem, call a new kdump friendly function,
crash_smp_send_stop(), instead of the smp_send_stop() when
crash_kexec_post_notifiers is enabled. crash_smp_send_stop() is a weak
function, and it just call smp_send_stop(). Architecture codes should
override it so that kdump can work appropriately. This patch only
provides x86-specific version.
For Xen's PV kernel, just keep the current behavior.
NOTES:
- Right solution would be to place crash_smp_send_stop() before
__crash_kexec() invocation in all cases and remove smp_send_stop(), but
we can't do that until all architectures implement own
crash_smp_send_stop()
- crash_smp_send_stop()-like work is still needed by
machine_crash_shutdown() because crash_kexec() can be called without
entering panic()
Fixes: f06e5153f4ae (kernel/panic.c: add "crash_kexec_post_notifiers" option) Link: http://lkml.kernel.org/r/20160810080948.11028.15344.stgit@sysi4-13.yrl.intra.hitachi.co.jp Signed-off-by: Hidehiro Kawai <hidehiro.kawai.ez@hitachi.com> Reported-by: Daniel Walker <dwalker@fifo99.com> Cc: Dave Young <dyoung@redhat.com> Cc: Baoquan He <bhe@redhat.com> Cc: Vivek Goyal <vgoyal@redhat.com> Cc: Eric Biederman <ebiederm@xmission.com> Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Daniel Walker <dwalker@fifo99.com> Cc: Xunlei Pang <xpang@redhat.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Borislav Petkov <bp@suse.de> Cc: David Vrabel <david.vrabel@citrix.com> Cc: Toshi Kani <toshi.kani@hpe.com> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: David Daney <david.daney@cavium.com> Cc: Aaro Koskinen <aaro.koskinen@iki.fi> Cc: "Steven J. Hill" <steven.hill@cavium.com> Cc: Corey Minyard <cminyard@mvista.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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>
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>
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>
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>
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>
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>
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().
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:
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.
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.
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.
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())
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:
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:
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):
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)
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).
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()
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().
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>
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>
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).
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>
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>
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>
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>
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>
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>
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)
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>
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.
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>
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>
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>
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>
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>
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>
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
Żenczykowski.
* 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()
...
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
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
...
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
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
...
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
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
...
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
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()
...
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()
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
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
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.
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().
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
...
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()"
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