commit 2084140594 upstream.
There are a few subtle races, between change_protection_range (used by
mprotect and change_prot_numa) on one side, and NUMA page migration and
compaction on the other side.
The basic race is that there is a time window between when the PTE gets
made non-present (PROT_NONE or NUMA), and the TLB is flushed.
During that time, a CPU may continue writing to the page.
This is fine most of the time, however compaction or the NUMA migration
code may come in, and migrate the page away.
When that happens, the CPU may continue writing, through the cached
translation, to what is no longer the current memory location of the
process.
This only affects x86, which has a somewhat optimistic pte_accessible.
All other architectures appear to be safe, and will either always flush,
or flush whenever there is a valid mapping, even with no permissions
(SPARC).
The basic race looks like this:
CPU A CPU B CPU C
load TLB entry
make entry PTE/PMD_NUMA
fault on entry
read/write old page
start migrating page
change PTE/PMD to new page
read/write old page [*]
flush TLB
reload TLB from new entry
read/write new page
lose data
[*] the old page may belong to a new user at this point!
The obvious fix is to flush remote TLB entries, by making sure that
pte_accessible aware of the fact that PROT_NONE and PROT_NUMA memory may
still be accessible if there is a TLB flush pending for the mm.
This should fix both NUMA migration and compaction.
[mgorman@suse.de: fix build]
Signed-off-by: Rik van Riel <riel@redhat.com>
Signed-off-by: Mel Gorman <mgorman@suse.de>
Cc: Alex Thorlton <athorlton@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit e0acd0a68e upstream.
This is only theoretical, but after try_to_wake_up(p) was changed
to check p->state under p->pi_lock the code like
__set_current_state(TASK_INTERRUPTIBLE);
schedule();
can miss a signal. This is the special case of wait-for-condition,
it relies on try_to_wake_up/schedule interaction and thus it does
not need mb() between __set_current_state() and if(signal_pending).
However, this __set_current_state() can move into the critical
section protected by rq->lock, now that try_to_wake_up() takes
another lock we need to ensure that it can't be reordered with
"if (signal_pending(current))" check inside that section.
The patch is actually one-liner, it simply adds smp_wmb() before
spin_lock_irq(rq->lock). This is what try_to_wake_up() already
does by the same reason.
We turn this wmb() into the new helper, smp_mb__before_spinlock(),
for better documentation and to allow the architectures to change
the default implementation.
While at it, kill smp_mb__after_lock(), it has no callers.
Perhaps we can also add smp_mb__before/after_spinunlock() for
prepare_to_wait().
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit c3a489cac3 upstream.
The anon_vma lock prevents parallel THP splits and any associated
complexity that arises when handling splits during THP migration. This
patch checks if the lock was successfully acquired and bails from THP
migration if it failed for any reason.
Signed-off-by: Mel Gorman <mgorman@suse.de>
Reviewed-by: Rik van Riel <riel@redhat.com>
Cc: Alex Thorlton <athorlton@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 67f87463d3 upstream.
On x86, PMD entries are similar to _PAGE_PROTNONE protection and are
handled as NUMA hinting faults. The following two page table protection
bits are what defines them
_PAGE_NUMA:set _PAGE_PRESENT:clear
A PMD is considered present if any of the _PAGE_PRESENT, _PAGE_PROTNONE,
_PAGE_PSE or _PAGE_NUMA bits are set. If pmdp_invalidate encounters a
pmd_numa, it clears the present bit leaving _PAGE_NUMA which will be
considered not present by the CPU but present by pmd_present. The
existing caller of pmdp_invalidate should handle it but it's an
inconsistent state for a PMD. This patch keeps the state consistent
when calling pmdp_invalidate.
Signed-off-by: Mel Gorman <mgorman@suse.de>
Reviewed-by: Rik van Riel <riel@redhat.com>
Cc: Alex Thorlton <athorlton@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 13fcca8f25 upstream.
This reverts commit e38c0a1fbc.
Nikita Yushchenko reports:
While trying to make freescale p2020ds and mpc8572ds boards working
with mainline kernel, I faced that commit e38c0a1f (Handle
Both these boards have uli1575 chip.
Corresponding part in device tree is something like
uli1575@0 {
reg = <0x0 0x0 0x0 0x0 0x0>;
#size-cells = <2>;
#address-cells = <3>;
ranges = <0x2000000 0x0 0x80000000
0x2000000 0x0 0x80000000
0x0 0x20000000
0x1000000 0x0 0x0
0x1000000 0x0 0x0
0x0 0x10000>;
isa@1e {
...
I.e. it has #address-cells = <3>
With commit e38c0a1f reverted, devices under uli1575 are registered
correctly, e.g. for rtc
OF: ** translation for device /pcie@ffe09000/pcie@0/uli1575@0/isa@1e/rtc@70 **
OF: bus is isa (na=2, ns=1) on /pcie@ffe09000/pcie@0/uli1575@0/isa@1e
OF: translating address: 00000001 00000070
OF: parent bus is default (na=3, ns=2) on /pcie@ffe09000/pcie@0/uli1575@0
OF: walking ranges...
OF: ISA map, cp=0, s=1000, da=70
OF: parent translation for: 01000000 00000000 00000000
OF: with offset: 70
OF: one level translation: 00000000 00000000 00000070
OF: parent bus is pci (na=3, ns=2) on /pcie@ffe09000/pcie@0
OF: walking ranges...
OF: default map, cp=a0000000, s=20000000, da=70
OF: default map, cp=0, s=10000, da=70
OF: parent translation for: 01000000 00000000 00000000
OF: with offset: 70
OF: one level translation: 01000000 00000000 00000070
OF: parent bus is pci (na=3, ns=2) on /pcie@ffe09000
OF: walking ranges...
OF: PCI map, cp=0, s=10000, da=70
OF: parent translation for: 01000000 00000000 00000000
OF: with offset: 70
OF: one level translation: 01000000 00000000 00000070
OF: parent bus is default (na=2, ns=2) on /
OF: walking ranges...
OF: PCI map, cp=0, s=10000, da=70
OF: parent translation for: 00000000 ffc10000
OF: with offset: 70
OF: one level translation: 00000000 ffc10070
OF: reached root node
With commit e38c0a1f in place, address translation fails:
OF: ** translation for device /pcie@ffe09000/pcie@0/uli1575@0/isa@1e/rtc@70 **
OF: bus is isa (na=2, ns=1) on /pcie@ffe09000/pcie@0/uli1575@0/isa@1e
OF: translating address: 00000001 00000070
OF: parent bus is default (na=3, ns=2) on /pcie@ffe09000/pcie@0/uli1575@0
OF: walking ranges...
OF: ISA map, cp=0, s=1000, da=70
OF: parent translation for: 01000000 00000000 00000000
OF: with offset: 70
OF: one level translation: 00000000 00000000 00000070
OF: parent bus is pci (na=3, ns=2) on /pcie@ffe09000/pcie@0
OF: walking ranges...
OF: default map, cp=a0000000, s=20000000, da=70
OF: default map, cp=0, s=10000, da=70
OF: not found !
Thierry Reding confirmed this commit was not needed after all:
"We ended up merging a different address representation for Tegra PCIe
and I've confirmed that reverting this commit doesn't cause any obvious
regressions. I think all other drivers in drivers/pci/host ended up
copying what we did on Tegra, so I wouldn't expect any other breakage
either."
There doesn't appear to be a simple way to support both behaviours, so
reverting this as nothing should be depending on the new behaviour.
Signed-off-by: Rob Herring <robh@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit bd02cd2549 upstream.
Evan Huus found (by fuzzing in wireshark) that the radiotap
iterator code can access beyond the length of the buffer if
the first bitmap claims an extension but then there's no
data at all. Fix this.
Reported-by: Evan Huus <eapache@gmail.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 85fbd722ad upstream.
Freezable kthreads and workqueues are fundamentally problematic in
that they effectively introduce a big kernel lock widely used in the
kernel and have already been the culprit of several deadlock
scenarios. This is the latest occurrence.
During resume, libata rescans all the ports and revalidates all
pre-existing devices. If it determines that a device has gone
missing, the device is removed from the system which involves
invalidating block device and flushing bdi while holding driver core
layer locks. Unfortunately, this can race with the rest of device
resume. Because freezable kthreads and workqueues are thawed after
device resume is complete and block device removal depends on
freezable workqueues and kthreads (e.g. bdi_wq, jbd2) to make
progress, this can lead to deadlock - block device removal can't
proceed because kthreads are frozen and kthreads can't be thawed
because device resume is blocked behind block device removal.
839a8e8660 ("writeback: replace custom worker pool implementation
with unbound workqueue") made this particular deadlock scenario more
visible but the underlying problem has always been there - the
original forker task and jbd2 are freezable too. In fact, this is
highly likely just one of many possible deadlock scenarios given that
freezer behaves as a big kernel lock and we don't have any debug
mechanism around it.
I believe the right thing to do is getting rid of freezable kthreads
and workqueues. This is something fundamentally broken. For now,
implement a funny workaround in libata - just avoid doing block device
hot[un]plug while the system is frozen. Kernel engineering at its
finest. :(
v2: Add EXPORT_SYMBOL_GPL(pm_freezing) for cases where libata is built
as a module.
v3: Comment updated and polling interval changed to 10ms as suggested
by Rafael.
v4: Add #ifdef CONFIG_FREEZER around the hack as pm_freezing is not
defined when FREEZER is not configured thus breaking build.
Reported by kbuild test robot.
Signed-off-by: Tejun Heo <tj@kernel.org>
Reported-by: Tomaž Šolc <tomaz.solc@tablix.org>
Reviewed-by: "Rafael J. Wysocki" <rjw@rjwysocki.net>
Link: https://bugzilla.kernel.org/show_bug.cgi?id=62801
Link: http://lkml.kernel.org/r/20131213174932.GA27070@htj.dyndns.org
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Len Brown <len.brown@intel.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: kbuild test robot <fengguang.wu@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 966fbe193f upstream.
Some device require DMADIR to be enabled, but are not detected as such
by atapi_id_dmadir. One such example is "Asus Serillel 2"
SATA-host-to-PATA-device bridge: the bridge itself requires DMADIR,
even if the bridged device does not.
As atapi_dmadir module parameter can cause problems with some devices
(as per Tejun Heo's memory), enabling it globally may not be possible
depending on the hardware.
This patch adds atapi_dmadir in the form of a "force" horkage value,
allowing global, per-bus and per-device control.
Signed-off-by: Vincent Pelletier <plr.vincent@gmail.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 87809942d3 upstream.
We've received multiple reports in Fedora via (BZ 907193)
that the Seagate Momentus SpinPoint M8 errors out when enabling AA:
[ 2.555905] ata2.00: failed to enable AA (error_mask=0x1)
[ 2.568482] ata2.00: failed to enable AA (error_mask=0x1)
Add the ATA_HORKAGE_BROKEN_FPDMA_AA for this specific harddisk.
Reported-by: Nicholas <arealityfarbetween@googlemail.com>
Signed-off-by: Michele Baldessari <michele@acksyn.org>
Tested-by: Nicholas <arealityfarbetween@googlemail.com>
Acked-by: Alan Cox <gnomes@lxorguk.ukuu.org.uk>
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit f447ef4a56 upstream.
If a user calls 'cpupower set --perf-bias 15', the process will end with
a SIGSEGV in libc because cpupower-set passes a NULL optarg to the atoi
call. This is because the getopt_long structure currently has all of
the options as having an optional_argument when they really have a
required argument. We change the structure to use required_argument to
match the short options and it resolves the issue.
This fixes https://bugzilla.redhat.com/show_bug.cgi?id=1000439
Signed-off-by: Josh Boyer <jwboyer@fedoraproject.org>
Cc: Dominik Brodowski <linux@dominikbrodowski.net>
Cc: Thomas Renninger <trenn@suse.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 286e4f90a7 upstream.
p_end is an 8 byte value embedded in the text section. This means it
is only 4 byte aligned when it should be 8 byte aligned. Fix this
by adding an explicit alignment.
This fixes an issue where POWER7 little endian builds with
CONFIG_RELOCATABLE=y fail to boot.
Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 90ff5d688e upstream.
In EXCEPTION_PROLOG_COMMON() we check to see if the stack pointer (r1)
is valid when coming from the kernel. If it's not valid, we die but
with a nice oops message.
Currently we allocate a stack frame (subtract INT_FRAME_SIZE) before we
check to see if the stack pointer is negative. Unfortunately, this
won't detect a bad stack where r1 is less than INT_FRAME_SIZE.
This patch fixes the check to compare the modified r1 with
-INT_FRAME_SIZE. With this, bad kernel stack pointers (including NULL
pointers) are correctly detected again.
Kudos to Paulus for finding this.
Signed-off-by: Michael Neuling <mikey@neuling.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit e66d2ae7c6 upstream.
Update arch.apic_base before triggering recalculate_apic_map. Otherwise
the recalculation will work against the previous state of the APIC and
will fail to build the correct map when an APIC is hardware-enabled
again.
This fixes a regression of 1e08ec4a13.
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 657eb17d87 upstream.
Pick the MAC address of the first virtual interface as the new hardware MAC
address. Set BSSID mask according to this MAC address. This fixes CVE-2013-4579.
Signed-off-by: Mathy Vanhoef <vanhoefm@gmail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 73f0b56a1f upstream.
This patch adds a driver workaround for a HW issue.
A race condition in the HW results in missing interrupts,
which can be avoided by a read/write with the ISR register.
All chips in the AR9002 series are affected by this bug - AR9003
and above do not have this problem.
Cc: Felix Fietkau <nbd@openwrt.org>
Signed-off-by: Sujith Manoharan <c_manoha@qca.qualcomm.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 4263c86dca upstream.
Certain dm962x revisions contain an bug, where if a USB bulk transfer retry
(E.G. if bulk crc mismatch) happens right after a transfer with odd or
maxpacket length, the internal tx hardware fifo gets out of sync causing
the interface to stop working.
Work around it by adding up to 3 bytes of padding to ensure this situation
cannot trigger.
This workaround also means we never pass multiple-of-maxpacket size skb's
to usbnet, so the length adjustment to handle usbnet's padding of those can
be removed.
Reported-by: Joseph Chang <joseph_chang@davicom.com.tw>
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 375679104a upstream.
The current driver assumes that an skb fragment can only be upto jumbo
size. Presumably this was a fast-path optimization. This assumption is
no longer true as fragments can be upto 32k.
v2: Remove unnecessary parantheses per Eric Dumazet.
Signed-off-by: Nithin Nayak Sujir <nsujir@broadcom.com>
Signed-off-by: Michael Chan <mchan@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 56f91aad69 upstream.
If the length of data to be read in readpage() is exactly
PAGE_CACHE_SIZE, the original code does not flush d-cache
for data consistency after finishing reading. This patches fixes
this.
Signed-off-by: Li Wang <liwang@ubuntukylin.com>
Signed-off-by: Sage Weil <sage@inktank.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
