Andrew Morton [Sat, 10 Sep 2016 10:34:30 +0000 (20:34 +1000)] 
relay-use-irq_work-instead-of-plain-timer-for-deferred-wakeup-checkpatch-fixes
ERROR: Please use git commit description style 'commit <12+ chars of sha1> ("<title line>")' - ie: 'commit
0123456789ab ("commit description")'
#12:
commit
7c9cb38302e78d24e37f7d8a2ea7eed4ae5f2fa7
WARNING: line over 80 characters
#87: FILE: kernel/relay.c:337:
+ struct rchan_buf *buf = container_of(work, struct rchan_buf, wakeup_work);
WARNING: waitqueue_active without comment
#119: FILE: kernel/relay.c:772:
+ if (waitqueue_active(&buf->read_wait)) {
total: 1 errors, 2 warnings, 70 lines checked
NOTE: For some of the reported defects, checkpatch may be able to
mechanically convert to the typical style using --fix or --fix-inplace.
./patches/relay-use-irq_work-instead-of-plain-timer-for-deferred-wakeup.patch has style problems, please review.
NOTE: If any of the errors are false positives, please report
them to the maintainer, see CHECKPATCH in MAINTAINERS.
Please run checkpatch prior to sending patches
Cc: Akash Goel <akash.goel@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Peter Zijlstra [Sat, 10 Sep 2016 10:34:30 +0000 (20:34 +1000)] 
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.
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: Andrew Morton <akpm@linux-foundation.org>
Hidehiro Kawai [Sat, 10 Sep 2016 10:34:30 +0000 (20:34 +1000)] 
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>
Hidehiro Kawai [Sat, 10 Sep 2016 10:34:30 +0000 (20:34 +1000)]
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>
Mauricio Faria de Oliveira [Sat, 10 Sep 2016 10:34:30 +0000 (20:34 +1000)] 
nvme: use the DMA_ATTR_NO_WARN attribute
Use the DMA_ATTR_NO_WARN attribute for the dma_map_sg() call of the nvme
driver that returns BLK_MQ_RQ_QUEUE_BUSY (not for BLK_MQ_RQ_QUEUE_ERROR).
Link: http://lkml.kernel.org/r/1470092390-25451-4-git-send-email-mauricfo@linux.vnet.ibm.com
Signed-off-by: Mauricio Faria de Oliveira <mauricfo@linux.vnet.ibm.com>
Reviewed-by: Gabriel Krisman Bertazi <krisman@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>
Mauricio Faria de Oliveira [Sat, 10 Sep 2016 10:34:30 +0000 (20:34 +1000)]
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>
Mauricio Faria de Oliveira [Sat, 10 Sep 2016 10:34:29 +0000 (20:34 +1000)]
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>
Jason Cooper [Sat, 10 Sep 2016 10:34:29 +0000 (20:34 +1000)] 
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>
Jason Cooper [Sat, 10 Sep 2016 10:34:29 +0000 (20:34 +1000)]
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>
Jason Cooper [Sat, 10 Sep 2016 10:34:29 +0000 (20:34 +1000)]
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>
Jason Cooper [Sat, 10 Sep 2016 10:34:29 +0000 (20:34 +1000)]
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>
Jason Cooper [Sat, 10 Sep 2016 10:34:28 +0000 (20:34 +1000)]
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>
Jason Cooper [Sat, 10 Sep 2016 10:34:28 +0000 (20:34 +1000)]
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>
Jason Cooper [Sat, 10 Sep 2016 10:34:28 +0000 (20:34 +1000)]
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>
Alexandre Bounine [Sat, 10 Sep 2016 10:34:28 +0000 (20:34 +1000)] 
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>
HATAYAMA Daisuke [Sat, 10 Sep 2016 10:34:28 +0000 (20:34 +1000)] 
kdump, vmcoreinfo: report actual value of phys_base
Currently, VMCOREINFO note information reports the virtual address of
phys_base that is assigned to symbol phys_base. But this doesn't make
sense because to refer to phys_base, it's necessary to get the value of
phys_base itself we are now about to refer to.
Userland tools related to kdump such as makedumpfile and crash utility so
far have made some efforts to calculate phys_base on crash dump formats
generated by mechanisms running outside Linux kernel, such as virtual
machine hypervisor such as qemu dump, which ordinary users use via virsh
dump, or ones implemented on vendor specific firmware.
That is, find a kernel data whose virtual and physical addresses are
available via its note information and calculate phys_base from it.
However, such data structure is not the one prepared for phys_base
purpose. There's no guarantee that other crash dump mechanisms include
such information that can be used to calculate phys_base similarly.
To get VMCOREINFO in vmcore, it's easy to use strings and grep commands
like this; VMCOREINFO consists of simple string:
$ strings vmcore-3.10.0-121.el7.x86_64 | grep -E ".*VMCOREINFO.*" -A 100
VMCOREINFO
OSRELEASE=3.10.0-121.el7.x86_64
PAGESIZE=4096
...
This is also useful to get value of phys_base in kdump 2nd kernel
contained in vmcore using the above-mentioned external crash dump
mechanism; kdump 2nd kernel is an inherently relocated kernel.
This commit doesn't remove VMCOREINFO_SYMBOL(phys_base) line because
makedumpfile refers to it and if removing it, old versions makedumpfile
doesn't work well.
Signed-off-by: HATAYAMA Daisuke <d.hatayama@jp.fujitsu.com>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Cc: Vivek Goyal <vgoyal@redhat.com>
Cc: Atsushi Kumagai <kumagai-atsushi@mxc.nes.nec.co.jp>
Cc: Dave Anderson <anderson@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Ales Novak [Sat, 10 Sep 2016 10:34:27 +0000 (20:34 +1000)] 
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>
Michael Kerrisk (man-pages) [Sat, 10 Sep 2016 10:34:27 +0000 (20:34 +1000)] 
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.
Patch history:
v2
* Switch order of tests in an 'if' statement to avoid a function
call (to capability()) in normal path. [Thanks to Willy Tarreau]
Link: http://lkml.kernel.org/r/31dc7064-2a17-9c5b-1df1-4e3012ee992c@gmail.com
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
Cc: Willy Tarreau <w@1wt.eu>
Cc: Vegard Nossum <vegard.nossum@oracle.com>
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>
Michael Kerrisk (man-pages) [Sat, 10 Sep 2016 10:34:27 +0000 (20:34 +1000)]
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>
Cc: Willy Tarreau <w@1wt.eu>
Cc: Vegard Nossum <vegard.nossum@oracle.com>
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>
Michael Kerrisk (man-pages) [Sat, 10 Sep 2016 10:34:27 +0000 (20:34 +1000)]
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.
Patch history:
v2
* Rework accounting checks to ensure that user cant get past
too_many_pipe_buffers_soft() before the accounting is done.
[Thanks to Vegard Nossum]
Link: http://lkml.kernel.org/r/8ff3e9f9-23f6-510c-644f-8e70cd1c0bd9@gmail.com
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
Cc: Willy Tarreau <w@1wt.eu>
Cc: Vegard Nossum <vegard.nossum@oracle.com>
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>
Michael Kerrisk (man-pages) [Sat, 10 Sep 2016 10:34:27 +0000 (20:34 +1000)]
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>
Cc: Willy Tarreau <w@1wt.eu>
Cc: Vegard Nossum <vegard.nossum@oracle.com>
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>
Michael Kerrisk (man-pages) [Sat, 10 Sep 2016 10:34:26 +0000 (20:34 +1000)]
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>
Cc: Willy Tarreau <w@1wt.eu>
Cc: Vegard Nossum <vegard.nossum@oracle.com>
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>
Michael Kerrisk (man-pages) [Sat, 10 Sep 2016 10:34:26 +0000 (20:34 +1000)]
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>
Cc: Willy Tarreau <w@1wt.eu>
Cc: Vegard Nossum <vegard.nossum@oracle.com>
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>
Michael Kerrisk (man-pages) [Sat, 10 Sep 2016 10:34:26 +0000 (20:34 +1000)]
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>
Cc: Willy Tarreau <w@1wt.eu>
Cc: Vegard Nossum <vegard.nossum@oracle.com>
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>
Michael Kerrisk (man-pages) [Sat, 10 Sep 2016 10:34:26 +0000 (20:34 +1000)]
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>
Cc: Willy Tarreau <w@1wt.eu>
Cc: Vegard Nossum <vegard.nossum@oracle.com>
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>
Tomohiro Kusumi [Sat, 10 Sep 2016 10:34:26 +0000 (20:34 +1000)] 
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>
Tomohiro Kusumi [Sat, 10 Sep 2016 10:34:26 +0000 (20:34 +1000)]
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>
Ian Kent [Sat, 10 Sep 2016 10:34:25 +0000 (20:34 +1000)] 
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>
Tomohiro Kusumi [Sat, 10 Sep 2016 10:34:25 +0000 (20:34 +1000)]
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>
Tomohiro Kusumi [Sat, 10 Sep 2016 10:34:25 +0000 (20:34 +1000)]
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>
Ian Kent [Sat, 10 Sep 2016 10:34:25 +0000 (20:34 +1000)]
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>
Tomohiro Kusumi [Sat, 10 Sep 2016 10:34:25 +0000 (20:34 +1000)]
autofs: fix "fix dev ioctl number range check"
102a340f had a typo that made the count macro negative (-13).
The acutal check used by ioctl is ((cmd - cmd_first) > COUNT),
so it needs to be positive (13).
*
102a340f is a commit in linux-next which hasn't been merged
to mainline upstream.
Link: http://lkml.kernel.org/r/20160831033420.9910.16809.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>
Ian Kent [Sat, 10 Sep 2016 10:34:25 +0000 (20:34 +1000)]
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).
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>
Tomohiro Kusumi [Sat, 10 Sep 2016 10:34:24 +0000 (20:34 +1000)]
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>
Tomohiro Kusumi [Sat, 10 Sep 2016 10:34:24 +0000 (20:34 +1000)]
autofs: update struct autofs_dev_ioctl in Documentation
Sync with changes made by
730c9eec 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>
Tomohiro Kusumi [Sat, 10 Sep 2016 10:34:24 +0000 (20:34 +1000)]
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>
Tomohiro Kusumi [Sat, 10 Sep 2016 10:34:24 +0000 (20:34 +1000)]
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>
Tomohiro Kusumi [Sat, 10 Sep 2016 10:34:24 +0000 (20:34 +1000)]
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>
Tomohiro Kusumi [Sat, 10 Sep 2016 10:34:24 +0000 (20:34 +1000)]
autofs: remove obsolete sb fields
These two were left from
aa55ddf3 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>
Tomohiro Kusumi [Sat, 10 Sep 2016 10:34:23 +0000 (20:34 +1000)]
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>
Ian Kent [Sat, 10 Sep 2016 10:34:23 +0000 (20:34 +1000)]
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>
Tomohiro Kusumi [Sat, 10 Sep 2016 10:34:23 +0000 (20:34 +1000)]
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>
Ian Kent [Sat, 10 Sep 2016 10:34:23 +0000 (20:34 +1000)]
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>
Tomohiro Kusumi [Sat, 10 Sep 2016 10:34:23 +0000 (20:34 +1000)]
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>
Tomohiro Kusumi [Sat, 10 Sep 2016 10:34:22 +0000 (20:34 +1000)]
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>
Tomohiro Kusumi [Sat, 10 Sep 2016 10:34:22 +0000 (20:34 +1000)]
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>
Joe Perches [Sat, 10 Sep 2016 10:34:22 +0000 (20:34 +1000)] 
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>
Joe Perches [Sat, 10 Sep 2016 10:34:22 +0000 (20:34 +1000)]
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>
Joe Perches [Sat, 10 Sep 2016 10:34:22 +0000 (20:34 +1000)]
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>
Joe Perches [Sat, 10 Sep 2016 10:34:22 +0000 (20:34 +1000)]
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>
Joe Perches [Sat, 10 Sep 2016 10:34:21 +0000 (20:34 +1000)]
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>
Joe Perches [Sat, 10 Sep 2016 10:34:21 +0000 (20:34 +1000)]
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>
Joe Perches [Sat, 10 Sep 2016 10:34:21 +0000 (20:34 +1000)]
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>
Joe Perches [Sat, 10 Sep 2016 10:34:21 +0000 (20:34 +1000)]
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>
Arnd Bergmann [Sat, 10 Sep 2016 10:34:21 +0000 (20:34 +1000)] 
compat: remove compat_printk()
After
7e8e385aaf6e ("x86/compat: Remove sys32_vm86_warning"), this
function has become unused, so we can remove it as well.
Link: http://lkml.kernel.org/r/20160617142903.3070388-1-arnd@arndb.de
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: "Theodore Ts'o" <tytso@mit.edu>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Marian Chereji [Sat, 10 Sep 2016 10:34:20 +0000 (20:34 +1000)] 
lib: Add CRC64 ECMA module
Add implementation of CRC64 ECMA checksum.
We have an IP Acceleration driver for Freescale network processors which
is using this CRC64. However, it still needs some work in order for it to
become upstreamable.
Signed-off-by: Marian Chereji <marian.chereji@freescale.com>
Reviewed-by: Varvara Andrei-B21317 <andrei.varvara@freescale.com>
Reviewed-by: Fleming Andrew-AFLEMING <AFLEMING@freescale.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Alexey Dobriyan [Sat, 10 Sep 2016 10:34:20 +0000 (20:34 +1000)] 
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>
Alexey Dobriyan [Sat, 10 Sep 2016 10:34:20 +0000 (20:34 +1000)]
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>
Mark Rutland [Sat, 10 Sep 2016 10:34:20 +0000 (20:34 +1000)] 
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>
Ross Zwisler [Sat, 10 Sep 2016 10:34:20 +0000 (20:34 +1000)] 
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>
Ross Zwisler [Sat, 10 Sep 2016 10:34:20 +0000 (20:34 +1000)]
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>
Ross Zwisler [Sat, 10 Sep 2016 10:34:19 +0000 (20:34 +1000)]
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>
Paul Burton [Sat, 10 Sep 2016 10:34:19 +0000 (20:34 +1000)] 
console: don't prefer first registered if DT specifies stdout-path
If a device tree specifies a preferred device for kernel console output
via the stdout-path or linux,stdout-path chosen node properties or the
stdout alias then the kernel ought to honor it & output the kernel console
to that device. As it stands, this isn't the case. Whilst we parse the
stdout-path properties & set an of_stdout variable from of_alias_scan(),
and use that from of_console_check() to determine whether to add a console
device as a preferred console whilst registering it, we also prefer the
first registered console if no other has been selected at the time of its
registration.
This means that if a console other than the one the device tree selects
via stdout-path is registered first, we will switch to using it & when the
stdout-path console is later registered the call to
add_preferred_console() via of_console_check() is too late to do anything
useful. In practice this seems to mean that we switch to the dummy
console device fairly early & see no further console output:
Console: colour dummy device 80x25
console [tty0] enabled
bootconsole [ns16550a0] disabled
Fix this by not automatically preferring the first registered console if
one is specified by the device tree. This allows consoles to be
registered but not enabled, and once the driver for the console selected
by stdout-path calls of_console_check() the driver will be added to the
list of preferred consoles before any other console has been enabled.
When that console is then registered via register_console() it will be
enabled as expected.
Link: http://lkml.kernel.org/r/20160809151937.26118-1-paul.burton@imgtec.com
Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Paul Burton <paul.burton@imgtec.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Cc: Jiri Slaby <jslaby@suse.cz>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Ivan Delalande <colona@arista.com>
Cc: Thierry Reding <treding@nvidia.com>
Cc: Borislav Petkov <bp@suse.de>
Cc: Jan Kara <jack@suse.com>
Cc: Petr Mladek <pmladek@suse.com>
Cc: Joe Perches <joe@perches.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Rob Herring <robh+dt@kernel.org>
Cc: Frank Rowand <frowand.list@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Alexey Dobriyan [Sat, 10 Sep 2016 10:34:19 +0000 (20:34 +1000)]
cred: simpler, 1D supplementary groups
Current supplementary groups code can massively overallocate memory and is
implemented in a way so that access to individual gid is done via 2D
array.
If number of gids is <= 32, memory allocation is more or less tolerable
(140/148 bytes). But if it is not, code allocates full page (!)
regardless and, what's even more fun, doesn't reuse small 32-entry array.
2D array means dependent shifts, loads and LEAs without possibility to
optimize them (gid is never known at compile time).
All of the above is unnecessary. Switch to the usual
trailing-zero-len-array scheme. Memory is allocated with
kmalloc/vmalloc() and only as much as needed. Accesses become simpler
(LEA 8(gi,idx,4) or even without displacement).
Maximum number of gids is 65536 which translates to 256KB+8 bytes. I
think kernel can handle such allocation.
On my usual desktop system with whole 9 (nine) aux groups,
struct group_info shrinks from 148 bytes to 44 bytes, yay!
Nice side effects:
* "gi->gid[i]" is shorter than "GROUP_AT(gi, i)", less typing,
* fix little mess in net/ipv4/ping.c
should have been using GROUP_AT macro but this point becomes moot,
* aux group allocation is persistent and should be accounted as such.
Link: http://lkml.kernel.org/r/20160817201927.GA2096@p183.telecom.by
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Vasily Kulikov <segoon@openwall.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Jean Delvare [Sat, 10 Sep 2016 10:34:19 +0000 (20:34 +1000)] 
.gitattributes: set git diff driver for C source code files
Git can be told to apply language-specific rules when generating diffs.
Enable this for C source code files (*.c and *.h) so that function names
are printed right. Specifically, doing so prevents "git diff" from
mistakenly considering unindented goto labels as function names.
Link: http://lkml.kernel.org/r/20160907143403.1449324f@endymion
Signed-off-by: Jean Delvare <jdelvare@suse.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Joe Perches <joe@perches.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Marcin Nowakowski [Sat, 10 Sep 2016 10:34:19 +0000 (20:34 +1000)] 
uprobes: remove function declarations from arch/{mips,s390}
The declarations of arch-specific functions have been moved to a common
header in commit
3820b4d2789f ('uprobes: Move function declarations out of
arch'), but MIPS and S390 has added them to their own trees later.
Remove the unnecessary duplicates.
Link: http://lkml.kernel.org/r/1472804384-17830-1-git-send-email-marcin.nowakowski@imgtec.com
Signed-off-by: Marcin Nowakowski <marcin.nowakowski@imgtec.com>
Acked-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Joe Perches [Sat, 10 Sep 2016 10:34:19 +0000 (20:34 +1000)]
spelling.txt: "modeled" is spelt correctly
No need to correct the correct.
Link: http://lkml.kernel.org/r/1472490791.3425.38.camel@perches.com
Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Chris Metcalf [Sat, 10 Sep 2016 10:34:18 +0000 (20:34 +1000)] 
nmi_backtrace: generate one-line reports for idle cpus
When doing an nmi backtrace of many cores, most of which are idle,
the output is a little overwhelming and very uninformative. Suppress
messages for cpus that are idling when they are interrupted and just
emit one line, "NMI backtrace for N skipped: idling at pc 0xNNN".
We do this by grouping all the cpuidle code together into a new
.cpuidle.text section, and then checking the address of the
interrupted PC to see if it lies within that section.
This commit suitably tags x86 and tile idle routines, and only
adds in the minimal framework for other architectures.
Link: http://lkml.kernel.org/r/1472487169-14923-5-git-send-email-cmetcalf@mellanox.com
Signed-off-by: Chris Metcalf <cmetcalf@mellanox.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Tested-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Tested-by: Daniel Thompson <daniel.thompson@linaro.org> [arm]
Tested-by: Petr Mladek <pmladek@suse.com>
Cc: Aaron Tomlin <atomlin@redhat.com>
Cc: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Chris Metcalf [Sat, 10 Sep 2016 10:34:18 +0000 (20:34 +1000)]
arch/tile: adopt the new nmi_backtrace framework
Previously tile was rolling its own method of capturing backtrace data in
the NMI handlers, but it was relying on running printk() from the NMI
handler, which is not always safe. So adopt the nmi_backtrace model (with
the new cpumask extension) instead.
So we can call the nmi_backtrace code directly from the nmi handler, move
the nmi_enter()/exit() into the top-level tile NMI handler.
The semantics of the routine change slightly since it is now synchronous
with the remote cores completing the backtraces. Previously it was
asynchronous, but with protection to avoid starting a new remote backtrace
if the old one was still in progress.
Link: http://lkml.kernel.org/r/1472487169-14923-4-git-send-email-cmetcalf@mellanox.com
Signed-off-by: Chris Metcalf <cmetcalf@mellanox.com>
Cc: Daniel Thompson <daniel.thompson@linaro.org> [arm]
Cc: Petr Mladek <pmladek@suse.com>
Cc: Aaron Tomlin <atomlin@redhat.com>
Cc: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Chris Metcalf [Sat, 10 Sep 2016 10:34:18 +0000 (20:34 +1000)]
nmi_backtrace: do a local dump_stack() instead of a self-NMI
Currently on arm there is code that checks whether it should call
dump_stack() explicitly, to avoid trying to raise an NMI when the current
context is not preemptible by the backtrace IPI. Similarly, the
forthcoming arch/tile support uses an IPI mechanism that does not support
generating an NMI to self.
Accordingly, move the code that guards this case into the generic
mechanism, and invoke it unconditionally whenever we want a backtrace of
the current cpu. It seems plausible that in all cases, dump_stack() will
generate better information than generating a stack from the NMI handler.
The register state will be missing, but that state is likely not
particularly helpful in any case.
Or, if we think it is helpful, we should be capturing and emitting the
current register state in all cases when regs == NULL is passed to
nmi_cpu_backtrace().
Link: http://lkml.kernel.org/r/1472487169-14923-3-git-send-email-cmetcalf@mellanox.com
Signed-off-by: Chris Metcalf <cmetcalf@mellanox.com>
Tested-by: Daniel Thompson <daniel.thompson@linaro.org> [arm]
Reviewed-by: Petr Mladek <pmladek@suse.com>
Acked-by: Aaron Tomlin <atomlin@redhat.com>
Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Chris Metcalf [Sat, 10 Sep 2016 10:34:18 +0000 (20:34 +1000)]
nmi_backtrace: add more trigger_*_cpu_backtrace() methods
Patch series "improvements to the nmi_backtrace code" v9.
This patch series modifies the trigger_xxx_backtrace() NMI-based remote
backtracing code to make it more flexible, and makes a few small
improvements along the way.
The motivation comes from the task isolation code, where there are
scenarios where we want to be able to diagnose a case where some cpu is
about to interrupt a task-isolated cpu. It can be helpful to see both
where the interrupting cpu is, and also an approximation of where the cpu
that is being interrupted is. The nmi_backtrace framework allows us to
discover the stack of the interrupted cpu.
I've tested that the change works as desired on tile, and build-tested
x86, arm, mips, and sparc64. For x86 I confirmed that the generic
cpuidle stuff as well as the architecture-specific routines are in the
new cpuidle section. For arm, mips, and sparc I just build-tested it
and made sure the generic cpuidle routines were in the new cpuidle
section, but I didn't attempt to figure out which the
platform-specific idle routines might be. That might be more usefully
done by someone with platform experience in follow-up patches.
This patch (of 4):
Currently you can only request a backtrace of either all cpus, or all cpus
but yourself. It can also be helpful to request a remote backtrace of a
single cpu, and since we want that, the logical extension is to support a
cpumask as the underlying primitive.
This change modifies the existing lib/nmi_backtrace.c code to take a
cpumask as its basic primitive, and modifies the linux/nmi.h code to use
the new "cpumask" method instead.
The existing clients of nmi_backtrace (arm and x86) are converted
to using the new cpumask approach in this change.
The other users of the backtracing API (sparc64 and mips) are converted to
use the cpumask approach rather than the all/allbutself approach. The
mips code ignored the "include_self" boolean but with this change it will
now also dump a local backtrace if requested.
Link: http://lkml.kernel.org/r/1472487169-14923-2-git-send-email-cmetcalf@mellanox.com
Signed-off-by: Chris Metcalf <cmetcalf@mellanox.com>
Tested-by: Daniel Thompson <daniel.thompson@linaro.org> [arm]
Reviewed-by: Aaron Tomlin <atomlin@redhat.com>
Reviewed-by: Petr Mladek <pmladek@suse.com>
Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: David Miller <davem@davemloft.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Johannes Berg [Sat, 10 Sep 2016 10:34:18 +0000 (20:34 +1000)] 
min/max: remove sparse warnings when they're nested
Currently, when min/max are nested within themselves, sparse will warn:
warning: symbol '_min1' shadows an earlier one
originally declared here
warning: symbol '_min1' shadows an earlier one
originally declared here
warning: symbol '_min2' shadows an earlier one
originally declared here
This also immediately happens when min3() or max3() are used.
Since sparse implements __COUNTER__, we can use __UNIQUE_ID() to generate
unique variable names, avoiding this.
Link: http://lkml.kernel.org/r/1471519773-29882-1-git-send-email-johannes@sipsolutions.net
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Cc: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Alexey Dobriyan [Sat, 10 Sep 2016 10:34:17 +0000 (20:34 +1000)]
proc: unsigned file descriptors
Make struct proc_inode::fd unsigned.
This allows better code generation on x86_64 (less sign extensions).
Link: http://lkml.kernel.org/r/20160901214202.GB7453@p183.telecom.by
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
John Stultz [Sat, 10 Sep 2016 10:34:17 +0000 (20:34 +1000)] 
proc: fix timerslack_ns CAP_SYS_NICE check when adjusting self
In changing from checking ptrace_may_access(p, PTRACE_MODE_ATTACH_FSCREDS)
to capable(CAP_SYS_NICE), I missed that ptrace_my_access succeeds when p
== current, but the CAP_SYS_NICE doesn't.
Thus while the previous commit was intended to loosen the needed
privileges to modify a processes timerslack, it needlessly restricted a
task modifying its own timerslack via the proc/<tid>/timerslack_ns (which
is permitted also via the PR_SET_TIMERSLACK method).
This patch corrects this by checking if p == current before checking
the CAP_SYS_NICE value.
This patch applies on top of my two previous patches currently in -mm
Link: http://lkml.kernel.org/r/1471906870-28624-1-git-send-email-john.stultz@linaro.org
Signed-off-by: John Stultz <john.stultz@linaro.org>
Acked-by: Kees Cook <keescook@chromium.org>
Cc: "Serge E. Hallyn" <serge@hallyn.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Arjan van de Ven <arjan@linux.intel.com>
Cc: Oren Laadan <orenl@cellrox.com>
Cc: Ruchi Kandoi <kandoiruchi@google.com>
Cc: Rom Lemarchand <romlem@android.com>
Cc: Todd Kjos <tkjos@google.com>
Cc: Colin Cross <ccross@android.com>
Cc: Nick Kralevich <nnk@google.com>
Cc: Dmitry Shmidt <dimitrysh@google.com>
Cc: Elliott Hughes <enh@google.com>
Cc: Android Kernel Team <kernel-team@android.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
John Stultz [Sat, 10 Sep 2016 10:34:17 +0000 (20:34 +1000)]
proc: add LSM hook checks to /proc/<tid>/timerslack_ns
As requested, this patch checks the existing LSM hooks
task_getscheduler/task_setscheduler when reading or modifying the task's
timerslack value.
Previous versions added new get/settimerslack LSM hooks, but since they
checked the same PROCESS__SET/GETSCHED values as existing hooks, it was
suggested we just use the existing ones.
Link: http://lkml.kernel.org/r/1469132667-17377-2-git-send-email-john.stultz@linaro.org
Signed-off-by: John Stultz <john.stultz@linaro.org>
Cc: Kees Cook <keescook@chromium.org>
Cc: "Serge E. Hallyn" <serge@hallyn.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Arjan van de Ven <arjan@linux.intel.com>
Cc: Oren Laadan <orenl@cellrox.com>
Cc: Ruchi Kandoi <kandoiruchi@google.com>
Cc: Rom Lemarchand <romlem@android.com>
Cc: Todd Kjos <tkjos@google.com>
Cc: Colin Cross <ccross@android.com>
Cc: Nick Kralevich <nnk@google.com>
Cc: Dmitry Shmidt <dimitrysh@google.com>
Cc: Elliott Hughes <enh@google.com>
Cc: James Morris <jmorris@namei.org>
Cc: Android Kernel Team <kernel-team@android.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
John Stultz [Sat, 10 Sep 2016 10:34:17 +0000 (20:34 +1000)]
proc: relax /proc/<tid>/timerslack_ns capability requirements
When an interface to allow a task to change another tasks timerslack was
first proposed, it was suggested that something greater then CAP_SYS_NICE
would be needed, as a task could be delayed further then what normally
could be done with nice adjustments.
So CAP_SYS_PTRACE was adopted instead for what became the
/proc/<tid>/timerslack_ns interface. However, for Android (where this
feature originates), giving the system_server CAP_SYS_PTRACE would allow
it to observe and modify all tasks memory. This is considered too high a
privilege level for only needing to change the timerslack.
After some discussion, it was realized that a CAP_SYS_NICE process can set
a task as SCHED_FIFO, so they could fork some spinning processes and set
them all SCHED_FIFO 99, in effect delaying all other tasks for an infinite
amount of time.
So as a CAP_SYS_NICE task can already cause trouble for other tasks, using
it as a required capability for accessing and modifying
/proc/<tid>/timerslack_ns seems sufficient.
Thus, this patch loosens the capability requirements to CAP_SYS_NICE and
removes CAP_SYS_PTRACE, simplifying some of the code flow as well.
This is technically an ABI change, but as the feature just landed in 4.6,
I suspect no one is yet using it.
Link: http://lkml.kernel.org/r/1469132667-17377-1-git-send-email-john.stultz@linaro.org
Signed-off-by: John Stultz <john.stultz@linaro.org>
Reviewed-by: Nick Kralevich <nnk@google.com>
Acked-by: Serge Hallyn <serge@hallyn.com>
Acked-by: Kees Cook <keescook@chromium.org>
Cc: Kees Cook <keescook@chromium.org>
Cc: "Serge E. Hallyn" <serge@hallyn.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Arjan van de Ven <arjan@linux.intel.com>
Cc: Oren Laadan <orenl@cellrox.com>
Cc: Ruchi Kandoi <kandoiruchi@google.com>
Cc: Rom Lemarchand <romlem@android.com>
Cc: Todd Kjos <tkjos@google.com>
Cc: Colin Cross <ccross@android.com>
Cc: Nick Kralevich <nnk@google.com>
Cc: Dmitry Shmidt <dimitrysh@google.com>
Cc: Elliott Hughes <enh@google.com>
Cc: Android Kernel Team <kernel-team@android.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Joe Perches [Sat, 10 Sep 2016 10:34:17 +0000 (20:34 +1000)]
meminfo: break apart a very long seq_printf with #ifdefs
Use a specific routine to emit most lines so that the code is
easier to read and maintain.
akpm:
text data bss dec hex filename
2976 8 0 2984 ba8 fs/proc/meminfo.o before
2669 8 0 2677 a75 fs/proc/meminfo.o after
Link: http://lkml.kernel.org/r/8fce7fdef2ba081a4ef531594e97da8a9feebb58.1470810406.git.joe@perches.com
Signed-off-by: Joe Perches <joe@perches.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Andrew Morton [Sat, 10 Sep 2016 10:34:17 +0000 (20:34 +1000)]
seq-proc-modify-seq_put_decimal_ll-to-take-a-const-char-not-char-fix
update vmstat_show(), per Joe
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Joe Perches <joe@perches.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Joe Perches [Sat, 10 Sep 2016 10:34:16 +0000 (20:34 +1000)]
seq/proc: modify seq_put_decimal_[u]ll to take a const char *, not char
Allow some seq_puts removals by taking a string instead of a single char.
Link: http://lkml.kernel.org/r/667e1cf3d436de91a5698170a1e98d882905e956.1470704995.git.joe@perches.com
Signed-off-by: Joe Perches <joe@perches.com>
Cc: Joe Perches <joe@perches.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Alexey Dobriyan [Sat, 10 Sep 2016 10:34:16 +0000 (20:34 +1000)]
proc: faster /proc/*/status
top(1) opens the following files for every PID:
/proc/*/stat
/proc/*/statm
/proc/*/status
This patch switches /proc/*/status away from seq_printf().
The result is 13.5% speedup.
Benchmark is open("/proc/self/status")+read+close 1.000.000 million times.
BEFORE
$ perf stat -r 10 taskset -c 3 ./proc-self-status
Performance counter stats for 'taskset -c 3 ./proc-self-status' (10 runs):
10748.474301 task-clock (msec) # 0.954 CPUs utilized ( +- 0.91% )
12 context-switches # 0.001 K/sec ( +- 1.09% )
1 cpu-migrations # 0.000 K/sec
104 page-faults # 0.010 K/sec ( +- 0.45% )
37,424,127,876 cycles # 3.482 GHz ( +- 0.04% )
8,453,010,029 stalled-cycles-frontend # 22.59% frontend cycles idle ( +- 0.12% )
3,747,609,427 stalled-cycles-backend # 10.01% backend cycles idle ( +- 0.68% )
65,632,764,147 instructions # 1.75 insn per cycle
# 0.13 stalled cycles per insn ( +- 0.00% )
13,981,324,775 branches # 1300.773 M/sec ( +- 0.00% )
138,967,110 branch-misses # 0.99% of all branches ( +- 0.18% )
11.
263885428 seconds time elapsed ( +- 0.04% )
^^^^^^^^^^^^
AFTER
$ perf stat -r 10 taskset -c 3 ./proc-self-status
Performance counter stats for 'taskset -c 3 ./proc-self-status' (10 runs):
9010.521776 task-clock (msec) # 0.925 CPUs utilized ( +- 1.54% )
11 context-switches # 0.001 K/sec ( +- 1.54% )
1 cpu-migrations # 0.000 K/sec ( +- 11.11% )
103 page-faults # 0.011 K/sec ( +- 0.60% )
32,352,310,603 cycles # 3.591 GHz ( +- 0.07% )
7,849,199,578 stalled-cycles-frontend # 24.26% frontend cycles idle ( +- 0.27% )
3,269,738,842 stalled-cycles-backend # 10.11% backend cycles idle ( +- 0.73% )
56,012,163,567 instructions # 1.73 insn per cycle
# 0.14 stalled cycles per insn ( +- 0.00% )
11,735,778,795 branches # 1302.453 M/sec ( +- 0.00% )
98,084,459 branch-misses # 0.84% of all branches ( +- 0.28% )
9.
741247736 seconds time elapsed ( +- 0.07% )
^^^^^^^^^^^
Link: http://lkml.kernel.org/r/20160806125608.GB1187@p183.telecom.by
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Joe Perches <joe@perches.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Alexey Dobriyan [Sat, 10 Sep 2016 10:34:16 +0000 (20:34 +1000)]
proc: much faster /proc/vmstat
Every current KDE system has process named ksysguardd polling files below
once in several seconds:
$ strace -e trace=open -p $(pidof ksysguardd)
Process 1812 attached
open("/etc/mtab", O_RDONLY|O_CLOEXEC) = 8
open("/etc/mtab", O_RDONLY|O_CLOEXEC) = 8
open("/proc/net/dev", O_RDONLY) = 8
open("/proc/net/wireless", O_RDONLY) = -1 ENOENT (No such file or directory)
open("/proc/stat", O_RDONLY) = 8
open("/proc/vmstat", O_RDONLY) = 8
Hell knows what it is doing but speed up reading /proc/vmstat by 33%!
Benchmark is open+read+close 1.000.000 times.
BEFORE
$ perf stat -r 10 taskset -c 3 ./proc-vmstat
Performance counter stats for 'taskset -c 3 ./proc-vmstat' (10 runs):
13146.768464 task-clock (msec) # 0.960 CPUs utilized ( +- 0.60% )
15 context-switches # 0.001 K/sec ( +- 1.41% )
1 cpu-migrations # 0.000 K/sec ( +- 11.11% )
104 page-faults # 0.008 K/sec ( +- 0.57% )
45,489,799,349 cycles # 3.460 GHz ( +- 0.03% )
9,970,175,743 stalled-cycles-frontend # 21.92% frontend cycles idle ( +- 0.10% )
2,800,298,015 stalled-cycles-backend # 6.16% backend cycles idle ( +- 0.32% )
79,241,190,850 instructions # 1.74 insn per cycle
# 0.13 stalled cycles per insn ( +- 0.00% )
17,616,096,146 branches # 1339.956 M/sec ( +- 0.00% )
176,106,232 branch-misses # 1.00% of all branches ( +- 0.18% )
13.
691078109 seconds time elapsed ( +- 0.03% )
^^^^^^^^^^^^
AFTER
$ perf stat -r 10 taskset -c 3 ./proc-vmstat
Performance counter stats for 'taskset -c 3 ./proc-vmstat' (10 runs):
8688.353749 task-clock (msec) # 0.950 CPUs utilized ( +- 1.25% )
10 context-switches # 0.001 K/sec ( +- 2.13% )
1 cpu-migrations # 0.000 K/sec
104 page-faults # 0.012 K/sec ( +- 0.56% )
30,384,010,730 cycles # 3.497 GHz ( +- 0.07% )
12,296,259,407 stalled-cycles-frontend # 40.47% frontend cycles idle ( +- 0.13% )
3,370,668,651 stalled-cycles-backend # 11.09% backend cycles idle ( +- 0.69% )
28,969,052,879 instructions # 0.95 insn per cycle
# 0.42 stalled cycles per insn ( +- 0.01% )
6,308,245,891 branches # 726.058 M/sec ( +- 0.00% )
214,685,502 branch-misses # 3.40% of all branches ( +- 0.26% )
9.
146081052 seconds time elapsed ( +- 0.07% )
^^^^^^^^^^^
vsnprintf() is slow because:
1. format_decode() is busy looking for format specifier: 2 branches
per character (not in this case, but in others)
2. approximately million branches while parsing format mini language
and everywhere
3. just look at what string() does /proc/vmstat is good case because
most of its content are strings
Link: http://lkml.kernel.org/r/20160806125455.GA1187@p183.telecom.by
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Joe Perches <joe@perches.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
zhong jiang [Sat, 10 Sep 2016 10:34:16 +0000 (20:34 +1000)] 
mm/vmstat.c: walk the zone in pageblock_nr_pages steps
when walking the zone, we can happens to the holes. we should not
align MAX_ORDER_NR_PAGES, so it can skip the normal memory.
In addition, pagetypeinfo_showmixedcount_print reflect fragmentization.
we hope to get more accurate data. therefore, I decide to fix it.
Link: http://lkml.kernel.org/r/1469502526-24486-2-git-send-email-zhongjiang@huawei.com
Signed-off-by: zhong jiang <zhongjiang@huawei.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
zhong jiang [Sat, 10 Sep 2016 10:34:16 +0000 (20:34 +1000)]
mm/page_owner: align with pageblock_nr pages
When pfn_valid(pfn) returns false, pfn should be aligned with
pageblock_nr_pages other than MAX_ORDER_NR_PAGES in init_pages_in_zone,
because the skipped 2M may be valid pfn, as a result, early allocated
count will not be accurate.
Link: http://lkml.kernel.org/r/1468938136-24228-1-git-send-email-zhongjiang@huawei.com
Signed-off-by: zhong jiang <zhongjiang@huawei.com>
Cc: Michal Hocko <mhocko@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Tetsuo Handa [Sat, 10 Sep 2016 10:34:15 +0000 (20:34 +1000)] 
mm: don't emit warning from pagefault_out_of_memory()
Commit
c32b3cbe0d067a9c ("oom, PM: make OOM detection in the freezer path
raceless") inserted a WARN_ON() into pagefault_out_of_memory() in order to
warn when we raced with disabling the OOM killer. But emitting same
backtrace forever after the OOM killer/reaper are disabled is pointless
because the system is already OOM livelocked.
Now, patch "oom, suspend: fix oom_killer_disable vs. pm suspend properly"
introduced a timeout for oom_killer_disable(). Even if we raced with
disabling the OOM killer and the system is OOM livelocked, the OOM killer
will be enabled eventually (in 20 seconds by default) and the OOM livelock
will be solved. Therefore, we no longer need to warn when we raced with
disabling the OOM killer.
Link: http://lkml.kernel.org/r/1473442120-7246-1-git-send-email-penguin-kernel@I-love.SAKURA.ne.jp
Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: David Rientjes <rientjes@google.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Vlastimil Babka [Sat, 10 Sep 2016 10:34:15 +0000 (20:34 +1000)] 
mm, compaction: make full priority ignore pageblock suitability
Several people have reported premature OOMs for order-2 allocations
(stack) due to OOM rework in 4.7. In the scenario (parallel kernel build
and dd writing to two drives) many pageblocks get marked as Unmovable and
compaction free scanner struggles to isolate free pages. Joonsoo Kim
pointed out that the free scanner skips pageblocks that are not movable to
prevent filling them and forcing non-movable allocations to fallback to
other pageblocks. Such heuristic makes sense to help prevent long-term
fragmentation, but premature OOMs are relatively more urgent problem. As
a compromise, this patch disables the heuristic only for the ultimate
compaction priority.
Link: http://lkml.kernel.org/r/20160906135258.18335-5-vbabka@suse.cz
Reported-by: Ralf-Peter Rohbeck <Ralf-Peter.Rohbeck@quantum.com>
Reported-by: Arkadiusz Miskiewicz <a.miskiewicz@gmail.com>
Reported-by: Olaf Hering <olaf@aepfle.de>
Suggested-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Vlastimil Babka [Sat, 10 Sep 2016 10:34:15 +0000 (20:34 +1000)]
mm, compaction: restrict full priority to non-costly orders
The new ultimate compaction priority disables some heuristics, which may
result in excessive cost. This is fine for non-costly orders where we
want to try hard before resulting for OOM, but might be disruptive for
costly orders which do not trigger OOM and should generally have some
fallback. Thus, we disable the full priority for costly orders.
Suggested-by: Michal Hocko <mhocko@kernel.org>
Link: http://lkml.kernel.org/r/20160906135258.18335-4-vbabka@suse.cz
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Vlastimil Babka [Sat, 10 Sep 2016 10:34:15 +0000 (20:34 +1000)]
mm, compaction: more reliably increase direct compaction priority
During reclaim/compaction loop, compaction priority can be increased by
the should_compact_retry() function, but the current code is not optimal.
Priority is only increased when compaction_failed() is true, which means
that compaction has scanned the whole zone. This may not happen even
after multiple attempts with a lower priority due to parallel activity, so
we might needlessly struggle on the lower priorities and possibly run out
of compaction retry attempts in the process.
After this patch we are guaranteed at least one attempt at the highest
compaction priority even if we exhaust all retries at the lower
priorities.
Link: http://lkml.kernel.org/r/20160906135258.18335-3-vbabka@suse.cz
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Vlastimil Babka [Sat, 10 Sep 2016 10:34:15 +0000 (20:34 +1000)]
Revert "mm, oom: prevent premature OOM killer invocation for high order request"
Patch series "reintroduce compaction feedback for OOM decisions".
After several people reported OOM's for order-2 allocations in 4.7 due to
Michal Hocko's OOM rework, he reverted the part that considered compaction
feedback [1] in the decisions to retry reclaim/compaction. This was to
provide a fix quickly for 4.8 rc and 4.7 stable series, while mmotm had an
almost complete solution that instead improved compaction reliability.
This series completes the mmotm solution and reintroduces the compaction
feedback into OOM decisions. The first two patches restore the state of
mmotm before the temporary solution was merged, the last patch should be
the missing piece for reliability. The third patch restricts the hardened
compaction to non-costly orders, since costly orders don't result in OOMs
in the first place.
[1] http://marc.info/?i=
20160822093249.GA14916%40dhcp22.suse.cz%3E
This patch (of 4):
Commit
6b4e3181d7bd ("mm, oom: prevent premature OOM killer invocation for
high order request") was intended as a quick fix of OOM regressions for
4.8 and stable 4.7.x kernels. For a better long-term solution, we still
want to consider compaction feedback, which should be possible after some
more improvements in the following patches.
This reverts commit
6b4e3181d7bd5ca5ab6f45929e4a5ffa7ab4ab7f.
Link: http://lkml.kernel.org/r/20160906135258.18335-2-vbabka@suse.cz
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Huang Ying [Sat, 10 Sep 2016 10:34:15 +0000 (20:34 +1000)] 
mm: Remove page_file_index
After using the offset of the swap entry as the key of the swap cache, the
page_index() becomes exactly same as page_file_index(). So the
page_file_index() is removed and the callers are changed to use
page_index() instead.
Link: http://lkml.kernel.org/r/1473270649-27229-2-git-send-email-ying.huang@intel.com
Signed-off-by: "Huang, Ying" <ying.huang@intel.com>
Cc: Trond Myklebust <trond.myklebust@primarydata.com>
Cc: Anna Schumaker <anna.schumaker@netapp.com>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Ross Zwisler <ross.zwisler@linux.intel.com>
Cc: Eric Dumazet <edumazet@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Huang Ying [Sat, 10 Sep 2016 10:34:14 +0000 (20:34 +1000)]
mm, swap: Use offset of swap entry as key of swap cache
This patch is to improve the performance of swap cache operations when the
type of the swap device is not 0. Originally, the whole swap entry value
is used as the key of the swap cache, even though there is one radix tree
for each swap device. If the type of the swap device is not 0, the height
of the radix tree of the swap cache will be increased unnecessary,
especially on 64bit architecture. For example, for a 1GB swap device on
the x86_64 architecture, the height of the radix tree of the swap cache is
11. But if the offset of the swap entry is used as the key of the swap
cache, the height of the radix tree of the swap cache is 4. The increased
height causes unnecessary radix tree descending and increased cache
footprint.
This patch reduces the height of the radix tree of the swap cache via
using the offset of the swap entry instead of the whole swap entry value
as the key of the swap cache. In 32 processes sequential swap out test
case on a Xeon E5 v3 system with RAM disk as swap, the lock contention for
the spinlock of the swap cache is reduced from 20.15% to 12.19%, when the
type of the swap device is 1.
Use the whole swap entry as key,
perf-profile.calltrace.cycles-pp._raw_spin_lock_irq.__add_to_swap_cache.add_to_swap_cache.add_to_swap.shrink_page_list: 10.37,
perf-profile.calltrace.cycles-pp._raw_spin_lock_irqsave.__remove_mapping.shrink_page_list.shrink_inactive_list.shrink_node_memcg: 9.78,
Use the swap offset as key,
perf-profile.calltrace.cycles-pp._raw_spin_lock_irq.__add_to_swap_cache.add_to_swap_cache.add_to_swap.shrink_page_list: 6.25,
perf-profile.calltrace.cycles-pp._raw_spin_lock_irqsave.__remove_mapping.shrink_page_list.shrink_inactive_list.shrink_node_memcg: 5.94,
Link: http://lkml.kernel.org/r/1473270649-27229-1-git-send-email-ying.huang@intel.com
Signed-off-by: "Huang, Ying" <ying.huang@intel.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Aaron Lu <aaron.lu@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Dan Williams [Sat, 10 Sep 2016 10:34:14 +0000 (20:34 +1000)] 
mm: fix cache mode tracking in vm_insert_mixed()
vm_insert_mixed() unlike vm_insert_pfn_prot() and vmf_insert_pfn_pmd(),
fails to check the pgprot_t it uses for the mapping against the one
recorded in the memtype tracking tree. Add the missing call to
track_pfn_insert() to preclude cases where incompatible aliased mappings
are established for a given physical address range.
Link: http://lkml.kernel.org/r/147328717909.35069.14256589123570653697.stgit@dwillia2-desk3.amr.corp.intel.com
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Cc: David Airlie <airlied@linux.ie>
Cc: Matthew Wilcox <mawilcox@microsoft.com>
Cc: Ross Zwisler <ross.zwisler@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reza Arbab [Sat, 10 Sep 2016 10:34:14 +0000 (20:34 +1000)] 
memory-hotplug: fix store_mem_state() return value
If store_mem_state() is called to online memory which is already online,
it will return 1, the value it got from device_online().
This is wrong because store_mem_state() is a device_attribute .store
function. Thus a non-negative return value represents input bytes read.
Set the return value to -EINVAL in this case.
Link: http://lkml.kernel.org/r/1472743777-24266-1-git-send-email-arbab@linux.vnet.ibm.com
Signed-off-by: Reza Arbab <arbab@linux.vnet.ibm.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Vitaly Kuznetsov <vkuznets@redhat.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Yaowei Bai <baiyaowei@cmss.chinamobile.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Xishi Qiu <qiuxishi@huawei.com>
Cc: David Vrabel <david.vrabel@citrix.com>
Cc: Chen Yucong <slaoub@gmail.com>
Cc: Andrew Banman <abanman@sgi.com>
Cc: Seth Jennings <sjenning@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
James Morse [Sat, 10 Sep 2016 10:34:14 +0000 (20:34 +1000)] 
mm/memcontrol.c: make the walk_page_range() limit obvious
mem_cgroup_count_precharge() and mem_cgroup_move_charge() both call
walk_page_range() on the range 0 to ~0UL, neither provide a pte_hole
callback, which causes the current implementation to skip non-vma
regions. This is all fine but follow up changes would like to make
walk_page_range more generic so it is better to be explicit about which
range to traverse so let's use highest_vm_end to explicitly traverse
only user mmaped memory.
[mhocko@kernel.org: rewrote changelog]
Link: http://lkml.kernel.org/r/1472655897-22532-1-git-send-email-james.morse@arm.com
Signed-off-by: James Morse <james.morse@arm.com>
Acked-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Vladimir Davydov <vdavydov@virtuozzo.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Aaron Lu [Sat, 10 Sep 2016 10:34:14 +0000 (20:34 +1000)] 
thp: reduce usage of huge zero page's atomic counter
The global zero page is used to satisfy an anonymous read fault. If
THP(Transparent HugePage) is enabled then the global huge zero page is
used. The global huge zero page uses an atomic counter for reference
counting and is allocated/freed dynamically according to its counter
value.
CPU time spent on that counter will greatly increase if there are a lot of
processes doing anonymous read faults. This patch proposes a way to
reduce the access to the global counter so that the CPU load can be
reduced accordingly.
To do this, a new flag of the mm_struct is introduced:
MMF_USED_HUGE_ZERO_PAGE. With this flag, the process only need to touch
the global counter in two cases:
1 The first time it uses the global huge zero page;
2 The time when mm_user of its mm_struct reaches zero.
Note that right now, the huge zero page is eligible to be freed as soon as
its last use goes away. With this patch, the page will not be eligible to
be freed until the exit of the last process from which it was ever used.
And with the use of mm_user, the kthread is not eligible to use huge zero
page either. Since no kthread is using huge zero page today, there is no
difference after applying this patch. But if that is not desired, I can
change it to when mm_count reaches zero.
Case used for test on Haswell EP:
usemem -n 72 --readonly -j 0x200000 100G
Which spawns 72 processes and each will mmap 100G anonymous space and
then do read only access to that space sequentially with a step of 2MB.
CPU cycles from perf report for base commit:
54.03% usemem [kernel.kallsyms] [k] get_huge_zero_page
CPU cycles from perf report for this commit:
0.11% usemem [kernel.kallsyms] [k] mm_get_huge_zero_page
Performance(throughput) of the workload for base commit:
1784430792
Performance(throughput) of the workload for this commit:
4726928591
164% increase.
Runtime of the workload for base commit: 707592 us
Runtime of the workload for this commit: 303970 us
50% drop.
Link: http://lkml.kernel.org/r/fe51a88f-446a-4622-1363-ad1282d71385@intel.com
Signed-off-by: Aaron Lu <aaron.lu@intel.com>
Cc: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Tim Chen <tim.c.chen@linux.intel.com>
Cc: Huang Ying <ying.huang@intel.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Jerome Marchand <jmarchan@redhat.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Ebru Akagunduz <ebru.akagunduz@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
James Morse [Sat, 10 Sep 2016 10:34:14 +0000 (20:34 +1000)]
fs/proc/task_mmu.c: make the task_mmu walk_page_range() limit in clear_refs_write() obvious
Trying to walk all of virtual memory requires architecture specific
knowledge. On x86_64, addresses must be sign extended from bit 48,
whereas on arm64 the top VA_BITS of address space have their own set of
page tables.
clear_refs_write() calls walk_page_range() on the range 0 to ~0UL, it
provides a test_walk() callback that only expects to be walking over VMAs.
Currently walk_pmd_range() will skip memory regions that don't have a
VMA, reporting them as a hole.
As this call only expects to walk user address space, make it walk 0 to
'highest_vm_end'.
Link: http://lkml.kernel.org/r/1472655792-22439-1-git-send-email-james.morse@arm.com
Signed-off-by: James Morse <james.morse@arm.com>
Acked-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Tim Chen [Sat, 10 Sep 2016 10:34:13 +0000 (20:34 +1000)] 
cpu: fix node state for whether it contains CPU
In current kernel code, we only call node_set_state(cpu_to_node(cpu),
N_CPU) when a cpu is hot plugged. But we do not set the node state for
N_CPU when the cpus are brought online during boot.
So this could lead to failure when we check to see if a node contains cpu
with node_state(node_id, N_CPU).
One use case is in the node_reclaime function:
/*
* Only run node reclaim on the local node or on nodes that do
* not
* have associated processors. This will favor the local
* processor
* over remote processors and spread off node memory allocations
* as wide as possible.
*/
if (node_state(pgdat->node_id, N_CPU) && pgdat->node_id !=
numa_node_id())
return NODE_RECLAIM_NOSCAN;
I instrumented the kernel to call this function after boot and it always
returns 0 on a x86 desktop machine until I apply the attached patch.
int num_cpu_node(void)
{
int i, nr_cpu_nodes = 0;
for_each_node(i) {
if (node_state(i, N_CPU))
++ nr_cpu_nodes;
}
return nr_cpu_nodes;
}
Fix this by checking each node for online CPU when we initialize
vmstat that's responsible for maintaining node state.
Link: http://lkml.kernel.org/r/20160829175922.GA21775@linux.intel.com
Signed-off-by: Tim Chen <tim.c.chen@linux.intel.com>
Acked-by: David Rientjes <rientjes@google.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Tim Chen <tim.c.chen@linux.intel.com>
Cc: <Huang@linux.intel.com>
Cc: Ying <ying.huang@intel.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Toshi Kani [Sat, 10 Sep 2016 10:34:13 +0000 (20:34 +1000)] 
ext2/4, xfs: call thp_get_unmapped_area() for pmd mappings
To support DAX pmd mappings with unmodified applications,
filesystems need to align an mmap address by the pmd size.
Call thp_get_unmapped_area() from f_op->get_unmapped_area.
Note, there is no change in behavior for a non-DAX file.
Link: http://lkml.kernel.org/r/1472497881-9323-3-git-send-email-toshi.kani@hpe.com
Signed-off-by: Toshi Kani <toshi.kani@hpe.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Matthew Wilcox <mawilcox@microsoft.com>
Cc: Ross Zwisler <ross.zwisler@linux.intel.com>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Theodore Ts'o <tytso@mit.edu>
Cc: Andreas Dilger <adilger.kernel@dilger.ca>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: "Kirill A. Shutemov" <kirill@shutemov.name>
Cc: Hugh Dickins <hughd@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Toshi Kani [Sat, 10 Sep 2016 10:34:13 +0000 (20:34 +1000)]
thp, dax: add thp_get_unmapped_area for pmd mappings
When CONFIG_FS_DAX_PMD is set, DAX supports mmap() using pmd page size.
This feature relies on both mmap virtual address and FS block (i.e.
physical address) to be aligned by the pmd page size. Users can use mkfs
options to specify FS to align block allocations. However, aligning mmap
address requires code changes to existing applications for providing a
pmd-aligned address to mmap().
For instance, fio with "ioengine=mmap" performs I/Os with mmap() [1]. It
calls mmap() with a NULL address, which needs to be changed to provide a
pmd-aligned address for testing with DAX pmd mappings. Changing all
applications that call mmap() with NULL is undesirable.
Add thp_get_unmapped_area(), which can be called by filesystem's
get_unmapped_area to align an mmap address by the pmd size for a DAX file.
It calls the default handler, mm->get_unmapped_area(), to find a range
and then aligns it for a DAX file.
The patch is based on Matthew Wilcox's change that allows adding support
of the pud page size easily.
[1]: https://github.com/axboe/fio/blob/master/engines/mmap.c
Link: http://lkml.kernel.org/r/1472497881-9323-2-git-send-email-toshi.kani@hpe.com
Signed-off-by: Toshi Kani <toshi.kani@hpe.com>
Reviewed-by: Dan Williams <dan.j.williams@intel.com>
Cc: Matthew Wilcox <mawilcox@microsoft.com>
Cc: Ross Zwisler <ross.zwisler@linux.intel.com>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Theodore Ts'o <tytso@mit.edu>
Cc: Andreas Dilger <adilger.kernel@dilger.ca>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: "Kirill A. Shutemov" <kirill@shutemov.name>
Cc: Hugh Dickins <hughd@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Simon Guo [Sat, 10 Sep 2016 10:34:13 +0000 (20:34 +1000)] 
selftests: expanding more mlock selftest
This patch will randomly perform mlock/mlock2 on a given memory region,
and verify the RLIMIT_MEMLOCK limitation works properly.
Suggested-by: David Rientjes <rientjes@google.com>
Link: http://lkml.kernel.org/r/1473325970-11393-4-git-send-email-wei.guo.simon@gmail.com
Signed-off-by: Simon Guo <wei.guo.simon@gmail.com>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Eric B Munson <emunson@akamai.com>
Cc: Simon Guo <wei.guo.simon@gmail.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Alexey Klimov <klimov.linux@gmail.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Thierry Reding <treding@nvidia.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Simon Guo [Sat, 10 Sep 2016 10:34:13 +0000 (20:34 +1000)]
selftest: move seek_to_smaps_entry() out of mlock2-tests.c
Function seek_to_smaps_entry() can be useful for other selftest
functionalities, so move it out to header file.
Link: http://lkml.kernel.org/r/1473325970-11393-3-git-send-email-wei.guo.simon@gmail.com
Signed-off-by: Simon Guo <wei.guo.simon@gmail.com>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Eric B Munson <emunson@akamai.com>
Cc: Simon Guo <wei.guo.simon@gmail.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Alexey Klimov <klimov.linux@gmail.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Thierry Reding <treding@nvidia.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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