commit bf7bd3e98b upstream.
This fixes a regression from 68a3396178
"nfsd4: shut down more of delegation earlier".
After that commit, nfs4_set_delegation() failures result in
nfs4_put_delegation being called, but nfs4_put_delegation doesn't free
the nfs4_file that has already been set by alloc_init_deleg().
This can result in an oops on later unmounting the exported filesystem.
Note also delaying the fi_had_conflict check we're able to return a
better error (hence give 4.1 clients a better idea why the delegation
failed; though note CONFLICT isn't an exact match here, as that's
supposed to indicate a current conflict, but all we know here is that
there was one recently).
Reported-by: Toralf Förster <toralf.foerster@gmx.de>
Tested-by: Toralf Förster <toralf.foerster@gmx.de>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
[tuomasjjrasanen: backported to 3.10
Conflicts fs/nfsd/nfs4state.c:
Delegation type flags have been removed from upstream code. In 3.10-series,
they still exists and therefore the commit caused few conflicts in function
signatures.
]
Signed-off-by: Tuomas Räsänen <tuomasjjrasanen@opinsys.fi>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit c6c15e1ed3 upstream.
The currect code for nfsd41_cb_get_slot() and nfsd4_cb_done() has no
locking in order to guarantee atomicity, and so allows for races of
the form.
Task 1 Task 2
====== ======
if (test_and_set_bit(0) != 0) {
clear_bit(0)
rpc_wake_up_next(queue)
rpc_sleep_on(queue)
return false;
}
This patch breaks the race condition by adding a retest of the bit
after the call to rpc_sleep_on().
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit cfd9167af1 upstream.
RT2800 and newer hardware require padding between header and payload if
header length is not multiple of 4.
For historical reasons we also align payload to to 4 bytes boundary, but
such alignment is not needed on modern H/W.
Patch fixes skb_under_panic problems reported from time to time:
https://bugzilla.kernel.org/show_bug.cgi?id=84911https://bugzilla.kernel.org/show_bug.cgi?id=72471http://marc.info/?l=linux-wireless&m=139108549530402&w=2https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1087591
Panic happened because we eat 4 bytes of skb headroom on each
(re)transmission when sending frame without the payload and the header
length not being multiple of 4 (i.e. QoS header has 26 bytes). On such
case because paylad_aling=2 is bigger than header_align=0 we increase
header_align by 4 bytes. To prevent that we could change the check to:
if (payload_length && payload_align > header_align)
header_align += 4;
but not aligning payload at all is more effective and alignment is not
really needed by H/W (that has been tested on OpenWrt project for few
years now).
Reported-and-tested-by: Antti S. Lankila <alankila@bel.fi>
Debugged-by: Antti S. Lankila <alankila@bel.fi>
Reported-by: Henrik Asp <solenskiner@gmail.com>
Originally-From: Helmut Schaa <helmut.schaa@googlemail.com>
Signed-off-by: Stanislaw Gruszka <sgruszka@redhat.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 0a8727e697 upstream.
An IOCTL call that calls spi_setup() and then dw_spi_setup() will
overwrite the persisted last transfer speed. On each transfer, the
SPI speed is compared to the last transfer speed to determine if the
clock divider registers need to be updated (did the speed change?).
This bug was observed with the spidev driver using spi-config to
update the max transfer speed.
This fix: Don't overwrite the persisted last transaction clock speed
when updating the SPI parameters in dw_spi_setup(). On the next
transaction, the new speed won't match the persisted last speed
and the hardware registers will be updated.
On initialization, the persisted last transaction clock
speed will be 0 but will be updated after the first SPI
transaction.
Move zeroed clock divider check into clock change test because
chip->clk_div is zero on startup and would cause a divide-by-zero
error. The calculation was wrong as well (can't support odd #).
Reported-by: Vlastimil Setka <setka@vsis.cz>
Signed-off-by: Vlastimil Setka <setka@vsis.cz>
Signed-off-by: Thor Thayer <tthayer@opensource.altera.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 3b726ae2de upstream.
In this case the cm_id->context is the isert_np, and the cm_id->qp
is NULL, so use that to distinct the cases.
Since we don't expect any other events on this cm_id we can
just return -1 for explicit termination of the cm_id by the
cma layer.
Signed-off-by: Sagi Grimberg <sagig@mellanox.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 885e7b0e18 upstream.
If an initiator sends a zero-length command (e.g. TEST UNIT READY) but
sets the transfer direction in the transport layer to indicate a
data-out phase, we still shouldn't try to transfer data. At best it's
a NOP, and depending on the transport, we might crash on an
uninitialized sg list.
Reported-by: Craig Watson <craig.watson@vanguard-rugged.com>
Signed-off-by: Roland Dreier <roland@purestorage.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit ab477c1ff5 upstream.
It is not guaranteed to that srp_sq_size is supported
by the HCA. So if we failed to create the QP with ENOMEM,
try with a smaller srp_sq_size. Keep it up until we hit
MIN_SRPT_SQ_SIZE, then fail the connection.
Reported-by: Mark Lehrer <lehrer@gmail.com>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Sagi Grimberg <sagig@mellanox.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit a1f9a40726 upstream.
The xpad wireless endpoint is not a bulk endpoint on my devices, but
rather an interrupt one, so the USB core complains when it is submitted.
I'm guessing that the author really did mean that this should be an
interrupt urb, but as there are a zillion different xpad devices out
there, let's cover out bases and handle both bulk and interrupt
endpoints just as easily.
Signed-off-by: "Pierre-Loup A. Griffais" <pgriffais@valvesoftware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 995ab5189d upstream.
Under extremely rare conditions, in an MPCore node consisting of at
least 3 CPUs, two CPUs trying to perform a STREX to data on the same
shared cache line can enter a livelock situation.
This patch enables the HW mechanism that overcomes the bug. This fixes
the incorrect setup of the STREX backoff delay bit due to a wrong
description in the specification.
Note that enabling the STREX backoff delay mechanism is done by
leaving the bit *cleared*, while the bit was currently being set by
the proc-v7.S code.
[Thomas: adapt to latest mainline, slightly reword the commit log, add
stable markers.]
Fixes: de4901933f ("arm: mm: Add support for PJ4B cpu and init routines")
Signed-off-by: Nadav Haklai <nadavh@marvell.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Acked-by: Gregory CLEMENT <gregory.clement@free-electrons.com>
Acked-by: Jason Cooper <jason@lakedaemon.net>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit ef59a20ba3 upstream.
According to the manuals I have, XScale auxiliary register should be
reached with opc_2 = 1 instead of crn = 1. cpu_xscale_proc_init
correctly uses c1, c0, 1 arguments, but cpu_xscale_do_suspend and
cpu_xscale_do_resume use c1, c1, 0. Correct suspend/resume functions to
also use c1, c0, 1.
The issue was primarily noticed thanks to qemu reporing "unsupported
instruction" on the pxa suspend path. Confirmed in PXA210/250 and PXA255
XScale Core manuals and in PXA270 and PXA320 Developers Guides.
Harware tested by me on tosa (pxa255). Robert confirmed on pxa270 board.
Tested-by: Robert Jarzmik <robert.jarzmik@free.fr>
Signed-off-by: Dmitry Eremin-Solenikov <dbaryshkov@gmail.com>
Acked-by: Robert Jarzmik <robert.jarzmik@free.fr>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 6e84a8d7ac upstream.
This patch adds a USB control message delay quirk for a few specific Marantz/Denon
devices. Without the delay the DACs will not work properly and produces the
following type of messages:
Nov 15 10:09:21 orwell kernel: [ 91.342880] usb 3-13: clock source 41 is not valid, cannot use
Nov 15 10:09:21 orwell kernel: [ 91.343775] usb 3-13: clock source 41 is not valid, cannot use
There are likely other Marantz/Denon devices using the same USB module which exhibit the
same problems. But as this cannot be verified I limited the patch to the devices
I could test.
The following two devices are covered by this path:
- Marantz SA-14S1
- Marantz HD-DAC1
Signed-off-by: Jurgen Kramer <gtmkramer@xs4all.nl>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit efbd50d2f6 upstream.
It seems struct esd_usb2 dev is not deallocated on disconnect. The patch adds
the missing deallocation.
Found by Linux Driver Verification project (linuxtesting.org).
Signed-off-by: Alexey Khoroshilov <khoroshilov@ispras.ru>
Acked-by: Matthias Fuchs <matthias.fuchs@esd.eu>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit c3492dbfa1 upstream.
A halted endpoint ring must first be reset, then move the ring
dequeue pointer past the problematic TRB. If we start the ring too
early after reset, but before moving the dequeue pointer we
will end up executing the same problematic TRB again.
As we always issue a set transfer dequeue command after a reset
endpoint command we can skip starting endpoint rings at reset endpoint
command completion.
Without this fix we end up trying to handle the same faulty TD for
contol endpoints. causing timeout, and failing testusb ctrl_out write
tests.
Fixes: e9df17e (USB: xhci: Correct assumptions about number of rings per endpoint.)
Tested-by: Felipe Balbi <balbi@ti.com>
Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 5d1678a33c upstream.
Fix handling of TTY error flags, which are not bitmasks and must
specifically not be ORed together as this prevents the line discipline
from recognising them.
Also insert null characters when reporting overrun errors as these are
not associated with the received character.
Fixes: 1da177e4c3 ("Linux-2.6.12-rc2")
Signed-off-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 855515a6d3 upstream.
Fix reporting of overrun errors, which are not associated with a
character. Instead insert a null character and report only once.
Fixes: 1da177e4c3 ("Linux-2.6.12-rc2")
Signed-off-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 75bcbf29c2 upstream.
Fix reporting of overrun errors, which should only be reported once
using the inserted null character.
Fixes: 6b8f1ca558 ("USB: ssu100: set tty_flags in ssu100_process_packet")
Signed-off-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit ccf54555da upstream.
The direction field is set on 7 bits, thus we need to AND it with 0111 111 mask
in order to retrieve it, that is 0x7F, not 0xCF as it is now.
Fixes: ade7ef7ba (staging:iio: Differential channel handling)
Signed-off-by: Cristina Ciocan <cristina.ciocan@intel.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 3b8a3c0109 upstream.
On pseries system (LPAR) xmon failed to enter when running in LE mode,
system is hunging. Inititating xmon will lead to such an output on the
console:
SysRq : Entering xmon
cpu 0x15: Vector: 0 at [c0000003f39ffb10]
pc: c00000000007ed7c: sysrq_handle_xmon+0x5c/0x70
lr: c00000000007ed7c: sysrq_handle_xmon+0x5c/0x70
sp: c0000003f39ffc70
msr: 8000000000009033
current = 0xc0000003fafa7180
paca = 0xc000000007d75e80 softe: 0 irq_happened: 0x01
pid = 14617, comm = bash
Bad kernel stack pointer fafb4b0 at eca7cc4
cpu 0x15: Vector: 300 (Data Access) at [c000000007f07d40]
pc: 000000000eca7cc4
lr: 000000000eca7c44
sp: fafb4b0
msr: 8000000000001000
dar: 10000000
dsisr: 42000000
current = 0xc0000003fafa7180
paca = 0xc000000007d75e80 softe: 0 irq_happened: 0x01
pid = 14617, comm = bash
cpu 0x15: Exception 300 (Data Access) in xmon, returning to main loop
xmon: WARNING: bad recursive fault on cpu 0x15
The root cause is that xmon is calling RTAS to turn off the surveillance
when entering xmon, and RTAS is requiring big endian parameters.
This patch is byte swapping the RTAS arguments when running in LE mode.
Signed-off-by: Laurent Dufour <ldufour@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 746c9e9f92 upstream.
We have a historical hack that treats missing ranges properties as the
equivalent of an empty one. This is needed for ancient PowerMac "bad"
device-trees, and shouldn't be enabled for any other PowerPC platform,
otherwise we get some nasty layout of devices in sysfs or even
duplication when a set of otherwise identically named devices is
created multiple times under a different parent node with no ranges
property.
This fix is needed for the PowerNV i2c busses to be exposed properly
and will fix a number of other embedded cases.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Acked-by: Grant Likely <grant.likely@linaro.org>
Signed-off-by: Rob Herring <robh@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 9da7a5a9fd upstream.
We should not free any buffers associated with writing out coefficients
to the DSP until all the async writes have completed. This patch updates
the out of memory path when allocating a new buffer to include a call to
regmap_async_complete.
Reported-by: JS Park <aitdark.park@samsung.com>
Signed-off-by: Charles Keepax <ckeepax@opensource.wolfsonmicro.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit c251ea7bd7 upstream.
On a mx28evk with a sgtl5000 codec we notice a loud 'click' sound to happen
5 seconds after the end of a playback.
The SMALL_POP bit should fix this, but its definition is incorrect:
according to the sgtl5000 manual it is bit 0 of CHIP_REF_CTRL register, not
bit 1.
Fix the definition accordingly and enable the bit as intended per the code
comment.
After applying this change, no loud 'click' sound is heard after playback
Signed-off-by: Fabio Estevam <fabio.estevam@freescale.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit f144d1496b upstream.
This can be set by quirks/drivers to be used by the architecture code
that assigns the MSI addresses.
We additionally add verification in the core MSI code that the values
assigned by the architecture do satisfy the limitation in order to fail
gracefully if they don't (ie. the arch hasn't been updated to deal with
that quirk yet).
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Acked-by: Bjorn Helgaas <bhelgaas@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit 01462405f0 ]
This fixes an old regression introduced by commit
b0d0d915 (ipx: remove the BKL).
When a recvmsg syscall blocks waiting for new data, no data can be sent on the
same socket with sendmsg because ipx_recvmsg() sleeps with the socket locked.
This breaks mars-nwe (NetWare emulator):
- the ncpserv process reads the request using recvmsg
- ncpserv forks and spawns nwconn
- ncpserv calls a (blocking) recvmsg and waits for new requests
- nwconn deadlocks in sendmsg on the same socket
Commit b0d0d915 has simply replaced BKL locking with
lock_sock/release_sock. Unlike now, BKL got unlocked while
sleeping, so a blocking recvmsg did not block a concurrent
sendmsg.
Only keep the socket locked while actually working with the socket data and
release it prior to calling skb_recv_datagram().
Signed-off-by: Jiri Bohac <jbohac@suse.cz>
Reviewed-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit a5f6fc28d6 ]
pptp_getname() only partially initializes the stack variable sa,
particularly only fills the pptp part of the sa_addr union. The code
thereby discloses 16 bytes of kernel stack memory via getsockname().
Fix this by memset(0)'ing the union before.
Cc: Dmitry Kozlov <xeb@mail.ru>
Signed-off-by: Mathias Krause <minipli@googlemail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit 8c2dd54485 ]
In case of any failure ieee802154fake_probe() just calls unregister_netdev().
But it does not look safe to unregister netdevice before it was registered.
The patch implements straightforward resource deallocation in case of
failure in ieee802154fake_probe().
Found by Linux Driver Verification project (linuxtesting.org).
Signed-off-by: Alexey Khoroshilov <khoroshilov@ispras.ru>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit 49dd18ba46 ]
Trying to add an unreachable route incorrectly returns -ESRCH if
if custom FIB rules are present:
[root@localhost ~]# ip route add 74.125.31.199 dev eth0 via 1.2.3.4
RTNETLINK answers: Network is unreachable
[root@localhost ~]# ip rule add to 55.66.77.88 table 200
[root@localhost ~]# ip route add 74.125.31.199 dev eth0 via 1.2.3.4
RTNETLINK answers: No such process
[root@localhost ~]#
Commit 83886b6b63 ("[NET]: Change "not found"
return value for rule lookup") changed fib_rules_lookup()
to use -ESRCH as a "not found" code internally, but for user space it
should be translated into -ENETUNREACH. Handle the translation centrally in
ipv4-specific fib_lookup(), leaving the DECnet case alone.
On a related note, commit b7a71b51ee
("ipv4: removed redundant conditional") removed a similar translation from
ip_route_input_slow() prematurely AIUI.
Fixes: b7a71b51ee ("ipv4: removed redundant conditional")
Signed-off-by: Panu Matilainen <pmatilai@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit 84bc88688e ]
There could be a signed overflow in the following code.
The expression, (32-logmask) is comprised between 0 and 31 included.
It may be equal to 31.
In such a case the left shift will produce a signed integer overflow.
According to the C99 Standard, this is an undefined behavior.
A simple fix is to replace the signed int 1 with the unsigned int 1U.
Signed-off-by: Vincent BENAYOUN <vincent.benayoun@trust-in-soft.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit 5a2b59d399 ]
We are reading the memory location, so we have to have a memory
constraint in there purely for the sake of showing the data flow
to the compiler.
Reported-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 82975bc6a6 upstream.
x86 call do_notify_resume on paranoid returns if TIF_UPROBE is set but
not on non-paranoid returns. I suspect that this is a mistake and that
the code only works because int3 is paranoid.
Setting _TIF_NOTIFY_RESUME in the uprobe code was probably a workaround
for the x86 bug. With that bug fixed, we can remove _TIF_NOTIFY_RESUME
from the uprobes code.
Reported-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Acked-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Andy Lutomirski <luto@amacapital.net>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 45e2a9d470 upstream.
When setting up permissions on kernel memory at boot, the end of the
PMD that was split from bss remained executable. It should be NX like
the rest. This performs a PMD alignment instead of a PAGE alignment to
get the correct span of memory.
Before:
---[ High Kernel Mapping ]---
...
0xffffffff8202d000-0xffffffff82200000 1868K RW GLB NX pte
0xffffffff82200000-0xffffffff82c00000 10M RW PSE GLB NX pmd
0xffffffff82c00000-0xffffffff82df5000 2004K RW GLB NX pte
0xffffffff82df5000-0xffffffff82e00000 44K RW GLB x pte
0xffffffff82e00000-0xffffffffc0000000 978M pmd
After:
---[ High Kernel Mapping ]---
...
0xffffffff8202d000-0xffffffff82200000 1868K RW GLB NX pte
0xffffffff82200000-0xffffffff82e00000 12M RW PSE GLB NX pmd
0xffffffff82e00000-0xffffffffc0000000 978M pmd
[ tglx: Changed it to roundup(_brk_end, PMD_SIZE) and added a comment.
We really should unmap the reminder along with the holes
caused by init,initdata etc. but thats a different issue ]
Signed-off-by: Kees Cook <keescook@chromium.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Toshi Kani <toshi.kani@hp.com>
Cc: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>
Cc: David Vrabel <david.vrabel@citrix.com>
Cc: Wang Nan <wangnan0@huawei.com>
Cc: Yinghai Lu <yinghai@kernel.org>
Link: http://lkml.kernel.org/r/20141114194737.GA3091@www.outflux.net
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 2cd3949f70 upstream.
We have some very similarly named command-line options:
arch/x86/kernel/cpu/common.c:__setup("noxsave", x86_xsave_setup);
arch/x86/kernel/cpu/common.c:__setup("noxsaveopt", x86_xsaveopt_setup);
arch/x86/kernel/cpu/common.c:__setup("noxsaves", x86_xsaves_setup);
__setup() is designed to match options that take arguments, like
"foo=bar" where you would have:
__setup("foo", x86_foo_func...);
The problem is that "noxsave" actually _matches_ "noxsaves" in
the same way that "foo" matches "foo=bar". If you boot an old
kernel that does not know about "noxsaves" with "noxsaves" on the
command line, it will interpret the argument as "noxsave", which
is not what you want at all.
This makes the "noxsave" handler only return success when it finds
an *exact* match.
[ tglx: We really need to make __setup() more robust. ]
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Dave Hansen <dave@sr71.net>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: x86@kernel.org
Link: http://lkml.kernel.org/r/20141111220133.FE053984@viggo.jf.intel.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit b645af2d59 upstream.
It's possible for iretq to userspace to fail. This can happen because
of a bad CS, SS, or RIP.
Historically, we've handled it by fixing up an exception from iretq to
land at bad_iret, which pretends that the failed iret frame was really
the hardware part of #GP(0) from userspace. To make this work, there's
an extra fixup to fudge the gs base into a usable state.
This is suboptimal because it loses the original exception. It's also
buggy because there's no guarantee that we were on the kernel stack to
begin with. For example, if the failing iret happened on return from an
NMI, then we'll end up executing general_protection on the NMI stack.
This is bad for several reasons, the most immediate of which is that
general_protection, as a non-paranoid idtentry, will try to deliver
signals and/or schedule from the wrong stack.
This patch throws out bad_iret entirely. As a replacement, it augments
the existing swapgs fudge into a full-blown iret fixup, mostly written
in C. It's should be clearer and more correct.
Signed-off-by: Andy Lutomirski <luto@amacapital.net>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 6f442be2fb upstream.
On a 32-bit kernel, this has no effect, since there are no IST stacks.
On a 64-bit kernel, #SS can only happen in user code, on a failed iret
to user space, a canonical violation on access via RSP or RBP, or a
genuine stack segment violation in 32-bit kernel code. The first two
cases don't need IST, and the latter two cases are unlikely fatal bugs,
and promoting them to double faults would be fine.
This fixes a bug in which the espfix64 code mishandles a stack segment
violation.
This saves 4k of memory per CPU and a tiny bit of code.
Signed-off-by: Andy Lutomirski <luto@amacapital.net>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit af726f21ed upstream.
There's nothing special enough about the espfix64 double fault fixup to
justify writing it in assembly. Move it to C.
This also fixes a bug: if the double fault came from an IST stack, the
old asm code would return to a partially uninitialized stack frame.
Fixes: 3891a04aaf
Signed-off-by: Andy Lutomirski <luto@amacapital.net>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 4942642080 upstream.
Commit 3812c8c8f3 ("mm: memcg: do not trap chargers with full
callstack on OOM") assumed that only a few places that can trigger a
memcg OOM situation do not return VM_FAULT_OOM, like optional page cache
readahead. But there are many more and it's impractical to annotate
them all.
First of all, we don't want to invoke the OOM killer when the failed
allocation is gracefully handled, so defer the actual kill to the end of
the fault handling as well. This simplifies the code quite a bit for
added bonus.
Second, since a failed allocation might not be the abrupt end of the
fault, the memcg OOM handler needs to be re-entrant until the fault
finishes for subsequent allocation attempts. If an allocation is
attempted after the task already OOMed, allow it to bypass the limit so
that it can quickly finish the fault and invoke the OOM killer.
Reported-by: azurIt <azurit@pobox.sk>
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 3812c8c8f3 upstream.
The memcg OOM handling is incredibly fragile and can deadlock. When a
task fails to charge memory, it invokes the OOM killer and loops right
there in the charge code until it succeeds. Comparably, any other task
that enters the charge path at this point will go to a waitqueue right
then and there and sleep until the OOM situation is resolved. The problem
is that these tasks may hold filesystem locks and the mmap_sem; locks that
the selected OOM victim may need to exit.
For example, in one reported case, the task invoking the OOM killer was
about to charge a page cache page during a write(), which holds the
i_mutex. The OOM killer selected a task that was just entering truncate()
and trying to acquire the i_mutex:
OOM invoking task:
mem_cgroup_handle_oom+0x241/0x3b0
mem_cgroup_cache_charge+0xbe/0xe0
add_to_page_cache_locked+0x4c/0x140
add_to_page_cache_lru+0x22/0x50
grab_cache_page_write_begin+0x8b/0xe0
ext3_write_begin+0x88/0x270
generic_file_buffered_write+0x116/0x290
__generic_file_aio_write+0x27c/0x480
generic_file_aio_write+0x76/0xf0 # takes ->i_mutex
do_sync_write+0xea/0x130
vfs_write+0xf3/0x1f0
sys_write+0x51/0x90
system_call_fastpath+0x18/0x1d
OOM kill victim:
do_truncate+0x58/0xa0 # takes i_mutex
do_last+0x250/0xa30
path_openat+0xd7/0x440
do_filp_open+0x49/0xa0
do_sys_open+0x106/0x240
sys_open+0x20/0x30
system_call_fastpath+0x18/0x1d
The OOM handling task will retry the charge indefinitely while the OOM
killed task is not releasing any resources.
A similar scenario can happen when the kernel OOM killer for a memcg is
disabled and a userspace task is in charge of resolving OOM situations.
In this case, ALL tasks that enter the OOM path will be made to sleep on
the OOM waitqueue and wait for userspace to free resources or increase
the group's limit. But a userspace OOM handler is prone to deadlock
itself on the locks held by the waiting tasks. For example one of the
sleeping tasks may be stuck in a brk() call with the mmap_sem held for
writing but the userspace handler, in order to pick an optimal victim,
may need to read files from /proc/<pid>, which tries to acquire the same
mmap_sem for reading and deadlocks.
This patch changes the way tasks behave after detecting a memcg OOM and
makes sure nobody loops or sleeps with locks held:
1. When OOMing in a user fault, invoke the OOM killer and restart the
fault instead of looping on the charge attempt. This way, the OOM
victim can not get stuck on locks the looping task may hold.
2. When OOMing in a user fault but somebody else is handling it
(either the kernel OOM killer or a userspace handler), don't go to
sleep in the charge context. Instead, remember the OOMing memcg in
the task struct and then fully unwind the page fault stack with
-ENOMEM. pagefault_out_of_memory() will then call back into the
memcg code to check if the -ENOMEM came from the memcg, and then
either put the task to sleep on the memcg's OOM waitqueue or just
restart the fault. The OOM victim can no longer get stuck on any
lock a sleeping task may hold.
Debugged by Michal Hocko.
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Reported-by: azurIt <azurit@pobox.sk>
Acked-by: Michal Hocko <mhocko@suse.cz>
Cc: David Rientjes <rientjes@google.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit fb2a6fc56b upstream.
The memcg OOM handler open-codes a sleeping lock for OOM serialization
(trylock, wait, repeat) because the required locking is so specific to
memcg hierarchies. However, it would be nice if this construct would be
clearly recognizable and not be as obfuscated as it is right now. Clean
up as follows:
1. Remove the return value of mem_cgroup_oom_unlock()
2. Rename mem_cgroup_oom_lock() to mem_cgroup_oom_trylock().
3. Pull the prepare_to_wait() out of the memcg_oom_lock scope. This
makes it more obvious that the task has to be on the waitqueue
before attempting to OOM-trylock the hierarchy, to not miss any
wakeups before going to sleep. It just didn't matter until now
because it was all lumped together into the global memcg_oom_lock
spinlock section.
4. Pull the mem_cgroup_oom_notify() out of the memcg_oom_lock scope.
It is proctected by the hierarchical OOM-lock.
5. The memcg_oom_lock spinlock is only required to propagate the OOM
lock in any given hierarchy atomically. Restrict its scope to
mem_cgroup_oom_(trylock|unlock).
6. Do not wake up the waitqueue unconditionally at the end of the
function. Only the lockholder has to wake up the next in line
after releasing the lock.
Note that the lockholder kicks off the OOM-killer, which in turn
leads to wakeups from the uncharges of the exiting task. But a
contender is not guaranteed to see them if it enters the OOM path
after the OOM kills but before the lockholder releases the lock.
Thus there has to be an explicit wakeup after releasing the lock.
7. Put the OOM task on the waitqueue before marking the hierarchy as
under OOM as that is the point where we start to receive wakeups.
No point in listening before being on the waitqueue.
8. Likewise, unmark the hierarchy before finishing the sleep, for
symmetry.
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Michal Hocko <mhocko@suse.cz>
Cc: David Rientjes <rientjes@google.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: azurIt <azurit@pobox.sk>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 3a13c4d761 upstream.
The x86 fault handler bails in the middle of error handling when the
task has a fatal signal pending. For a subsequent patch this is a
problem in OOM situations because it relies on pagefault_out_of_memory()
being called even when the task has been killed, to perform proper
per-task OOM state unwinding.
Shortcutting the fault like this is a rather minor optimization that
saves a few instructions in rare cases. Just remove it for
user-triggered faults.
Use the opportunity to split the fault retry handling from actual fault
errors and add locking documentation that reads suprisingly similar to
ARM's.
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Reviewed-by: Michal Hocko <mhocko@suse.cz>
Acked-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: David Rientjes <rientjes@google.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: azurIt <azurit@pobox.sk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
