If the owner died bit is set at futex_unlock_pi, we currently do not
cleanup the user space futex. So the owner TID of the current owner
(the unlocker) persists. That's observable inconsistant state,
especially when the ownership of the pi state got transferred.
Clean it up unconditionally.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Kees Cook <keescook@chromium.org>
Cc: Will Drewry <wad@chromium.org>
Cc: Darren Hart <dvhart@linux.intel.com>
Cc: stable@vger.kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
We need to protect the atomic acquisition in the kernel against rogue
user space which sets the user space futex to 0, so the kernel side
acquisition succeeds while there is existing state in the kernel
associated to the real owner.
Verify whether the futex has waiters associated with kernel state. If
it has, return -EINVAL. The state is corrupted already, so no point in
cleaning it up. Subsequent calls will fail as well. Not our problem.
[ tglx: Use futex_top_waiter() and explain why we do not need to try
restoring the already corrupted user space state. ]
Signed-off-by: Darren Hart <dvhart@linux.intel.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Will Drewry <wad@chromium.org>
Cc: stable@vger.kernel.org
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
If uaddr == uaddr2, then we have broken the rule of only requeueing from
a non-pi futex to a pi futex with this call. If we attempt this, then
dangling pointers may be left for rt_waiter resulting in an exploitable
condition.
This change brings futex_requeue() in line with futex_wait_requeue_pi()
which performs the same check as per commit 6f7b0a2a5c ("futex: Forbid
uaddr == uaddr2 in futex_wait_requeue_pi()")
[ tglx: Compare the resulting keys as well, as uaddrs might be
different depending on the mapping ]
Fixes CVE-2014-3153.
Reported-by: Pinkie Pie
Signed-off-by: Will Drewry <wad@chromium.org>
Signed-off-by: Kees Cook <keescook@chromium.org>
Cc: stable@vger.kernel.org
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Darren Hart <dvhart@linux.intel.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Pull powerpc fix from Ben Herrenschmidt:
"Here's just one trivial patch to wire up sys_renameat2 which I seem to
have completely missed so far.
(My test build scripts fwd me warnings but miss the ones generated for
missing syscalls)"
* 'merge' of git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc:
powerpc: Wire renameat2() syscall
Pull MIPS fixes from Ralf Baechle:
"A fair number of fixes across the field. Nothing terribly
complicated; the one liners in below changelog should be fairly
descriptive.
Noteworthy is the SB1 change which the result of changes to binutils
resulting in one big gas warning for most files being assembled as
well as the asid_cache and branch emulation fixes which fix corruption
or possible uninteded behaviour of kernel or application code. The
remainder of fixes are more platforms or subsystem specific"
* 'upstream' of git://git.linux-mips.org/pub/scm/ralf/upstream-linus:
MIPS: R46000: Fix Micro-assembler field overflow for R4600 V2
MIPS: ptrace: Avoid smp_processor_id() in preemptible code
MIPS: Lemote 2F: cs5536: mfgpt: use raw locks
MIPS: SB1: Fix excessive kernel warnings.
MIPS: RC32434: fix broken PCI resource initialization
MIPS: malta: memory.c: Initialize the 'memsize' variable
MIPS: Fix typo when reporting cache and ftlb errors for ImgTec cores
MIPS: Fix inconsistancy of __NR_Linux_syscalls value
MIPS: Fix branch emulation of branch likely instructions.
MIPS: Fix a typo error in AUDIT_ARCH definition
MIPS: Change type of asid_cache to unsigned long
Pull scheduler fixes from Ingo Molnar:
"Various fixlets, mostly related to the (root-only) SCHED_DEADLINE
policy, but also a hotplug bug fix and a fix for a NR_CPUS related
overallocation bug causing a suspend/resume regression"
* 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
sched: Fix hotplug vs. set_cpus_allowed_ptr()
sched/cpupri: Replace NR_CPUS arrays
sched/deadline: Replace NR_CPUS arrays
sched/deadline: Restrict user params max value to 2^63 ns
sched/deadline: Change sched_getparam() behaviour vs SCHED_DEADLINE
sched: Disallow sched_attr::sched_policy < 0
sched: Make sched_setattr() correctly return -EFBIG
Pull core futex/rtmutex fixes from Thomas Gleixner:
"Three fixlets for long standing issues in the futex/rtmutex code
unearthed by Dave Jones syscall fuzzer:
- Add missing early deadlock detection checks in the futex code
- Prevent user space from attaching a futex to kernel threads
- Make the deadlock detector of rtmutex work again
Looks large, but is more comments than code change"
* 'core-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
rtmutex: Fix deadlock detector for real
futex: Prevent attaching to kernel threads
futex: Add another early deadlock detection check
Pull drm fixes from Dave Airlie:
"Mostly quiet now:
i915:
fixing userspace visiblie issues, all stable marked
radeon:
one more pll fix, two crashers, one suspend/resume regression"
* 'drm-fixes' of git://people.freedesktop.org/~airlied/linux:
drm/radeon: Resume fbcon last
drm/radeon: only allocate necessary size for vm bo list
drm/radeon: don't allow RADEON_GEM_DOMAIN_CPU for command submission
drm/radeon: avoid crash if VM command submission isn't available
drm/radeon: lower the ref * post PLL maximum once more
drm/i915: Prevent negative relocation deltas from wrapping
drm/i915: Only copy back the modified fields to userspace from execbuffer
drm/i915: Fix dynamic allocation of physical handles
lock_parent() very much on purpose does nested locking of dentries, and
is careful to maintain the right order (lock parent first). But because
it didn't annotate the nested locking order, lockdep thought it might be
a deadlock on d_lock, and complained.
Add the proper annotation for the inner locking of the child dentry to
make lockdep happy.
Introduced by commit 046b961b45 ("shrink_dentry_list(): take parent's
->d_lock earlier").
Reported-and-tested-by: Josh Boyer <jwboyer@fedoraproject.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
So a few people complained that
commit 177cf92de4
Author: Daniel Vetter <daniel.vetter@ffwll.ch>
Date: Tue Apr 1 22:14:59 2014 +0200
drm/crtc-helpers: fix dpms on logic
which was merged into 3.15-rc1, broke resume on radeons. Strangely git
bisect lead everyone to
commit 25f397a429
Author: Daniel Vetter <daniel.vetter@ffwll.ch>
Date: Fri Jul 19 18:57:11 2013 +0200
drm/crtc-helper: explicit DPMS on after modeset
which was merged long ago and actually part of 3.14.
Digging deeper I've noticed (again) that the call to
drm_helper_resume_force_mode in the radeon resume handlers was a no-op
previously because everything gets shut down on suspend. radeon does
this with explicit calls to drm_helper_connector_dpms with DPMS_OFF.
But with 177c we now force the dpms state to ON, so suddenly
resume_force_mode actually forced the crtcs back on.
This is the intention of the change after all, the problem is that
radeon resumes the fbdev console layer _before_ restoring the display,
through calling fb_set_suspend. And fbcon does an immediate ->set_par,
which in turn causes the same forced mode restore to happen.
Two concurrent modeset operations didn't lead to happiness. Fix this
by delaying the fbcon resume until the end of the readeon resum
functions.
v2: Fix up a bit of the spelling fail.
References: https://lkml.org/lkml/2014/5/29/1043
References: https://lkml.org/lkml/2014/5/2/388
Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=74751
Tested-by: Ken Moffat <zarniwhoop@ntlworld.com>
Cc: Alex Deucher <alexdeucher@gmail.com>
Cc: Ken Moffat <zarniwhoop@ntlworld.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Dave Airlie <airlied@gmail.com>
this is the next pull request for stashed up radeon fixes for 3.15. This is finally calming down with only four patches in this pull request.
* 'drm-fixes-3.15' of git://people.freedesktop.org/~deathsimple/linux:
drm/radeon: only allocate necessary size for vm bo list
drm/radeon: don't allow RADEON_GEM_DOMAIN_CPU for command submission
drm/radeon: avoid crash if VM command submission isn't available
drm/radeon: lower the ref * post PLL maximum once more
Pull input subsystem fixes from Dmitry Torokhov:
"A couple of driver/build fixups and also redone quirk for Synaptics
touchpads on Lenovo boxes (now using PNP IDs instead of DMI data to
limit number of quirks)"
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input:
Input: synaptics - change min/max quirk table to pnp-id matching
Input: synaptics - add a matches_pnp_id helper function
Input: synaptics - T540p - unify with other LEN0034 models
Input: synaptics - add min/max quirk for the ThinkPad W540
Input: ambakmi - request a shared interrupt for AMBA KMI devices
Input: pxa27x-keypad - fix generating scancode
Input: atmel-wm97xx - only build for AVR32
Input: fix ps2/serio module dependency
because dm-cache cannot yet handle discards that span cache blocks.
Really fix a dm-mpath LOCKDEP warning that was introduced in -rc1.
Add a 'no_space_timeout' control to dm-thinp to restore the ability to
queue IO indefinitely when no data space is available. This fixes a
change in behavior that was introduced in -rc6 where the timeout
couldn't be disabled.
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Merge tag 'dm-3.15-fixes-3' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm
Pull device-mapper fixes from Mike Snitzer:
"A dm-cache stable fix to split discards on cache block boundaries
because dm-cache cannot yet handle discards that span cache blocks.
Really fix a dm-mpath LOCKDEP warning that was introduced in -rc1.
Add a 'no_space_timeout' control to dm-thinp to restore the ability to
queue IO indefinitely when no data space is available. This fixes a
change in behavior that was introduced in -rc6 where the timeout
couldn't be disabled"
* tag 'dm-3.15-fixes-3' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm:
dm mpath: really fix lockdep warning
dm cache: always split discards on cache block boundaries
dm thin: add 'no_space_timeout' dm-thin-pool module param
While I play inhouse patches with much memory pressure on qemu-kvm,
3.14 kernel was randomly crashed. The reason was kernel stack overflow.
When I investigated the problem, the callstack was a little bit deeper
by involve with reclaim functions but not direct reclaim path.
I tried to diet stack size of some functions related with alloc/reclaim
so did a hundred of byte but overflow was't disappeard so that I encounter
overflow by another deeper callstack on reclaim/allocator path.
Of course, we might sweep every sites we have found for reducing
stack usage but I'm not sure how long it saves the world(surely,
lots of developer start to add nice features which will use stack
agains) and if we consider another more complex feature in I/O layer
and/or reclaim path, it might be better to increase stack size(
meanwhile, stack usage on 64bit machine was doubled compared to 32bit
while it have sticked to 8K. Hmm, it's not a fair to me and arm64
already expaned to 16K. )
So, my stupid idea is just let's expand stack size and keep an eye
toward stack consumption on each kernel functions via stacktrace of ftrace.
For example, we can have a bar like that each funcion shouldn't exceed 200K
and emit the warning when some function consumes more in runtime.
Of course, it could make false positive but at least, it could make a
chance to think over it.
I guess this topic was discussed several time so there might be
strong reason not to increase kernel stack size on x86_64, for me not
knowing so Ccing x86_64 maintainers, other MM guys and virtio
maintainers.
Here's an example call trace using up the kernel stack:
Depth Size Location (51 entries)
----- ---- --------
0) 7696 16 lookup_address
1) 7680 16 _lookup_address_cpa.isra.3
2) 7664 24 __change_page_attr_set_clr
3) 7640 392 kernel_map_pages
4) 7248 256 get_page_from_freelist
5) 6992 352 __alloc_pages_nodemask
6) 6640 8 alloc_pages_current
7) 6632 168 new_slab
8) 6464 8 __slab_alloc
9) 6456 80 __kmalloc
10) 6376 376 vring_add_indirect
11) 6000 144 virtqueue_add_sgs
12) 5856 288 __virtblk_add_req
13) 5568 96 virtio_queue_rq
14) 5472 128 __blk_mq_run_hw_queue
15) 5344 16 blk_mq_run_hw_queue
16) 5328 96 blk_mq_insert_requests
17) 5232 112 blk_mq_flush_plug_list
18) 5120 112 blk_flush_plug_list
19) 5008 64 io_schedule_timeout
20) 4944 128 mempool_alloc
21) 4816 96 bio_alloc_bioset
22) 4720 48 get_swap_bio
23) 4672 160 __swap_writepage
24) 4512 32 swap_writepage
25) 4480 320 shrink_page_list
26) 4160 208 shrink_inactive_list
27) 3952 304 shrink_lruvec
28) 3648 80 shrink_zone
29) 3568 128 do_try_to_free_pages
30) 3440 208 try_to_free_pages
31) 3232 352 __alloc_pages_nodemask
32) 2880 8 alloc_pages_current
33) 2872 200 __page_cache_alloc
34) 2672 80 find_or_create_page
35) 2592 80 ext4_mb_load_buddy
36) 2512 176 ext4_mb_regular_allocator
37) 2336 128 ext4_mb_new_blocks
38) 2208 256 ext4_ext_map_blocks
39) 1952 160 ext4_map_blocks
40) 1792 384 ext4_writepages
41) 1408 16 do_writepages
42) 1392 96 __writeback_single_inode
43) 1296 176 writeback_sb_inodes
44) 1120 80 __writeback_inodes_wb
45) 1040 160 wb_writeback
46) 880 208 bdi_writeback_workfn
47) 672 144 process_one_work
48) 528 112 worker_thread
49) 416 240 kthread
50) 176 176 ret_from_fork
[ Note: the problem is exacerbated by certain gcc versions that seem to
generate much bigger stack frames due to apparently bad coalescing of
temporaries and generating too many spills. Rusty saw gcc-4.6.4 using
35% more stack on the virtio path than 4.8.2 does, for example.
Minchan not only uses such a bad gcc version (4.6.3 in his case), but
some of the stack use is due to debugging (CONFIG_DEBUG_PAGEALLOC is
what causes that kernel_map_pages() frame, for example). But we're
clearly getting too close.
The VM code also seems to have excessive stack frames partly for the
same compiler reason, triggered by excessive inlining and lots of
function arguments.
We need to improve on our stack use, but in the meantime let's do this
simple stack increase too. Unlike most earlier reports, there is
nothing simple that stands out as being really horribly wrong here,
apart from the fact that the stack frames are just bigger than they
should need to be. - Linus ]
Signed-off-by: Minchan Kim <minchan@kernel.org>
Cc: Peter Anvin <hpa@zytor.com>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Dave Jones <davej@redhat.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Rik van Riel <riel@redhat.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Hugh Dickins <hughd@google.com>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Michael S Tsirkin <mst@redhat.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: PJ Waskiewicz <pjwaskiewicz@gmail.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Pull vfs dcache livelock fix from Al Viro:
"Fixes for livelocks in shrink_dentry_list() introduced by fixes to
shrink list corruption; the root cause was that trylock of parent's
->d_lock could be disrupted by d_walk() happening on other CPUs,
resulting in shrink_dentry_list() making no progress *and* the same
d_walk() being called again and again for as long as
shrink_dentry_list() doesn't get past that mess.
The solution is to have shrink_dentry_list() treat that trylock
failure not as 'try to do the same thing again', but 'lock them in the
right order'"
* 'for-linus-2' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
dentry_kill() doesn't need the second argument now
dealing with the rest of shrink_dentry_list() livelock
shrink_dentry_list(): take parent's ->d_lock earlier
expand dentry_kill(dentry, 0) in shrink_dentry_list()
split dentry_kill()
lift the "already marked killed" case into shrink_dentry_list()
We have the same problem with ->d_lock order in the inner loop, where
we are dropping references to ancestors. Same solution, basically -
instead of using dentry_kill() we use lock_parent() (introduced in the
previous commit) to get that lock in a safe way, recheck ->d_count
(in case if lock_parent() has ended up dropping and retaking ->d_lock
and somebody managed to grab a reference during that window), trylock
the inode->i_lock and use __dentry_kill() to do the rest.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
The cause of livelocks there is that we are taking ->d_lock on
dentry and its parent in the wrong order, forcing us to use
trylock on the parent's one. d_walk() takes them in the right
order, and unfortunately it's not hard to create a situation
when shrink_dentry_list() can't make progress since trylock
keeps failing, and shrink_dcache_parent() or check_submounts_and_drop()
keeps calling d_walk() disrupting the very shrink_dentry_list() it's
waiting for.
Solution is straightforward - if that trylock fails, let's unlock
the dentry itself and take locks in the right order. We need to
stabilize ->d_parent without holding ->d_lock, but that's doable
using RCU. And we'd better do that in the very beginning of the
loop in shrink_dentry_list(), since the checks on refcount, etc.
would need to be redone anyway.
That deals with a half of the problem - killing dentries on the
shrink list itself. Another one (dropping their parents) is
in the next commit.
locking parent is interesting - it would be easy to do rcu_read_lock(),
lock whatever we think is a parent, lock dentry itself and check
if the parent is still the right one. Except that we need to check
that *before* locking the dentry, or we are risking taking ->d_lock
out of order. Fortunately, once the D1 is locked, we can check if
D2->d_parent is equal to D1 without the need to lock D2; D2->d_parent
can start or stop pointing to D1 only under D1->d_lock, so taking
D1->d_lock is enough. In other words, the right solution is
rcu_read_lock/lock what looks like parent right now/check if it's
still our parent/rcu_read_unlock/lock the child.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
It hangs the hardware.
Signed-off-by: Marek Olšák <marek.olsak@amd.com>
Reviewed-by: Christian König <christian.koenig@amd.com>
Cc: stable@vger.kernel.org
Pull ARM fixes from Russell King:
"The usual random collection of relatively small ARM fixes"
* 'fixes' of git://ftp.arm.linux.org.uk/~rmk/linux-arm:
ARM: 8063/1: bL_switcher: fix individual online status reporting of removed CPUs
ARM: 8064/1: fix v7-M signal return
ARM: 8057/1: amba: Add Qualcomm vendor ID.
ARM: 8052/1: unwind: Fix handling of "Pop r4-r[4+nnn],r14" opcode
ARM: 8051/1: put_user: fix possible data corruption in put_user
ARM: 8048/1: fix v7-M setup stack location
set_pte_at, which correctly handles PTE_WRITE and will mark the
resulting table entry as read-only where appropriate.
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Merge tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux
Pull arm64 fix from Will Deacon:
"Fix CoW regression for transparent hugepages by routing set_pmd_at to
set_pte_at, which correctly handles PTE_WRITE and will mark the
resulting table entry as read-only where appropriate"
* tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux:
arm64: mm: fix pmd_write CoW brokenness
- A workqueue is destroyed too early during the ACPI thermal driver
module unload which leads to a NULL pointer dereference in the
driver's remove callback. Fix from Aaron Lu.
- A wrong argument is passed to devm_regulator_get_optional() in
the probe routine of the cpu0 cpufreq driver which leads to
resource leaks if the driver is unbound from the cpufreq
platform device. Fix from Lucas Stach.
- A lock is missing in cpufreq_governor_dbs() which leads to
memory corruption and NULL pointer dereferences during
system suspend/resume, for example. Fix from Bibek Basu.
/
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Merge tag 'pm+acpi-3.15-rc8' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm
Pull ACPI and power management fixes from Rafael Wysocki:
"These are three stable-candidate fixes, one for the ACPI thermal
driver and two for cpufreq drivers.
Specifics:
- A workqueue is destroyed too early during the ACPI thermal driver
module unload which leads to a NULL pointer dereference in the
driver's remove callback. Fix from Aaron Lu.
- A wrong argument is passed to devm_regulator_get_optional() in the
probe routine of the cpu0 cpufreq driver which leads to resource
leaks if the driver is unbound from the cpufreq platform device.
Fix from Lucas Stach.
- A lock is missing in cpufreq_governor_dbs() which leads to memory
corruption and NULL pointer dereferences during system
suspend/resume, for example. Fix from Bibek Basu"
* tag 'pm+acpi-3.15-rc8' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
ACPI / thermal: fix workqueue destroy order
cpufreq: cpu0: drop wrong devm usage
cpufreq: remove race while accessing cur_policy
is a memory leak fix for an ST platform, an infinite Loop Of Doom fix
for the recent changes to the basic clock divider (hopefully the last
fix for those recent changes) and some Tegra PLL changes which keep PCI
from being hosed on that platform.
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Merge tag 'clk-fixes-for-linus' of git://git.linaro.org/people/mike.turquette/linux
Pull clock fixes from Mike Turquette:
"Small number of user-visible regression fixes for clock drivers.
There is a memory leak fix for an ST platform, an infinite Loop Of
Doom fix for the recent changes to the basic clock divider (hopefully
the last fix for those recent changes) and some Tegra PLL changes
which keep PCI from being hosed on that platform"
* tag 'clk-fixes-for-linus' of git://git.linaro.org/people/mike.turquette/linux:
clk: st: Fix memory leak
clk: divider: Fix table round up function
clk: tegra: Fix enabling of PLLE
clk: tegra: Introduce divider mask and shift helpers
clk: tegra: Fix PLLE programming
Undo a feature introduced in v3.14 by commit fcd46b3442
"firewire: Enable remote DMA above 4 GB". That change raised the
minimum address at which protocol drivers and user programs can register
for request reception from 0x0001'0000'0000 to 0x8000'0000'0000.
It turned out that at least one vendor-specific protocol exists which
uses lower addresses: https://bugzilla.kernel.org/show_bug.cgi?id=76921
For the time being, revert most of commit fcd46b3442 so that affected
protocols work like with kernel v3.13 and before. Just keep the valid
documentation parts from the regressing commit, and the ability to
identify controllers which could be programmed to accept >32 bit
physical DMA addresses. The rest of fcd46b3442 should probably be
brought back as an optional instead of default feature.
Reported-by: Fabien Spindler <fabien.spindler@inria.fr>
Cc: <stable@vger.kernel.org> # 3.14+
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
Result will be massaged to saner shape in the next commits. It is
ugly, no questions - the point of that one is to be a provably
equivalent transformation (and it might be worth splitting a bit
more).
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Commit 9c7e535fcc ("arm64: mm: Route pmd thp functions through pte
equivalents") changed the pmd manipulator and accessor functions to
convert the target pmd to a pte, process it with the pte functions, then
convert it back. Along the way, we gained support for PTE_WRITE, however
this is completely ignored by set_pmd_at, and so we fail to set the
PMD_SECT_RDONLY for PMDs, resulting in all sorts of lovely failures (like
CoW not working).
Partially reverting the offending commit (by making use of
PMD_SECT_RDONLY explicitly for pmd_{write,wrprotect,mkwrite} functions)
leads to further issues because pmd_write can then return potentially
incorrect values for page table entries marked as RDONLY, leading to
BUG_ON(pmd_write(entry)) tripping under some THP workloads.
This patch fixes the issue by routing set_pmd_at through set_pte_at,
which correctly takes the PTE_WRITE flag into account. Given that
THP mappings are always anonymous, the additional cache-flushing code
in __sync_icache_dcache won't impose any significant overhead as the
flush will be skipped.
Cc: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: Steve Capper <steve.capper@arm.com>
Tested-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Just two small stable fixes: an HD-audio fix for the new Intel chipsets
and a PM handling fix in PCM dmaengine core.
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Merge tag 'sound-3.15-rc8' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound
Pull sound fixes from Takashi Iwai:
"Just two small stable fixes: an HD-audio fix for the new Intel
chipsets and a PM handling fix in PCM dmaengine core"
* tag 'sound-3.15-rc8' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound:
ALSA: hda - Fix onboard audio on Intel H97/Z97 chipsets
ALSA: pcm_dmaengine: Add check during device suspend
Pull vfs fix from Al Viro:
"Oh, well... Still nothing useful on that livelock (I had something
that looked kinda-sorta like a non-invasive solution, but it
deadlocks), so it's just Miklos' vmsplice fix for now"
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
vfs: fix vmplice_to_user()
The content of /sys/devices/system/cpu/cpu*/online is still 1 for those
CPUs that the switcher has removed even though the global state in
/sys/devices/system/cpu/online is updated correctly.
It turns out that commit 0902a9044f ("Driver core: Use generic
offline/online for CPU offline/online") has changed the way those files
retrieve their content by relying on on the generic attribute handling
code. The switcher, by calling cpu_down() directly, bypasses this
handling and the attribute value doesn't get updated.
Fix this by calling device_offline()/device_online() instead.
Signed-off-by: Nicolas Pitre <nico@linaro.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
The current deadlock detection logic does not work reliably due to the
following early exit path:
/*
* Drop out, when the task has no waiters. Note,
* top_waiter can be NULL, when we are in the deboosting
* mode!
*/
if (top_waiter && (!task_has_pi_waiters(task) ||
top_waiter != task_top_pi_waiter(task)))
goto out_unlock_pi;
So this not only exits when the task has no waiters, it also exits
unconditionally when the current waiter is not the top priority waiter
of the task.
So in a nested locking scenario, it might abort the lock chain walk
and therefor miss a potential deadlock.
Simple fix: Continue the chain walk, when deadlock detection is
enabled.
We also avoid the whole enqueue, if we detect the deadlock right away
(A-A). It's an optimization, but also prevents that another waiter who
comes in after the detection and before the task has undone the damage
observes the situation and detects the deadlock and returns
-EDEADLOCK, which is wrong as the other task is not in a deadlock
situation.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Reviewed-by: Steven Rostedt <rostedt@goodmis.org>
Cc: Lai Jiangshan <laijs@cn.fujitsu.com>
Cc: stable@vger.kernel.org
Link: http://lkml.kernel.org/r/20140522031949.725272460@linutronix.de
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
The PPC fixes are important because they fix breakage that is new in 3.15.
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Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm
Pull kvm fixes from Paolo Bonzini:
"Small fixes for x86, slightly larger fixes for PPC, and a forgotten
s390 patch. The PPC fixes are important because they fix breakage
that is new in 3.15"
* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm:
KVM: s390: announce irqfd capability
KVM: x86: disable master clock if TSC is reset during suspend
KVM: vmx: disable APIC virtualization in nested guests
KVM guest: Make pv trampoline code executable
KVM: PPC: Book3S: ifdef on CONFIG_KVM_BOOK3S_32_HANDLER for 32bit
KVM: PPC: Book3S HV: Add missing code for transaction reclaim on guest exit
KVM: PPC: Book3S: HV: make _PAGE_NUMA take effect
Pull two powerpc fixes from Ben Herrenschmidt:
"Here's a pair of powerpc fixes for 3.15 which are also going to
stable.
One's a fix for building with newer binutils (the problem currently
only affects the BookE kernels but the affected macro might come back
into use on BookS platforms at any time). Unfortunately, the binutils
maintainer did a backward incompatible change to a construct that we
use so we have to add Makefile check.
The other one is a fix for CPUs getting stuck in kexec when running
single threaded. Since we routinely use kexec on power (including in
our newer bootloaders), I deemed that important enough"
* 'merge' of git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc:
powerpc, kexec: Fix "Processor X is stuck" issue during kexec from ST mode
powerpc: Fix 64 bit builds with binutils 2.24
It can happen only when dentry_kill() is called with unlock_on_failure
equal to 0 - other callers had dentry pinned until the moment they've
got ->d_lock and DCACHE_DENTRY_KILLED is set only after lockref_mark_dead().
IOW, only one of three call sites of dentry_kill() might end up reaching
that code. Just move it there.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
ptrace_{get,set}_watch_regs access current_cpu_data to get the watch
register count/masks, which calls smp_processor_id(). However they are
run in preemptible context and therefore trigger warnings like so:
[ 6340.092000] BUG: using smp_processor_id() in preemptible [00000000] code: gdb/367
[ 6340.092000] caller is ptrace_get_watch_regs+0x44/0x220
Since the watch register count/masks should be the same across all
CPUs, use boot_cpu_data instead. Note that this may need to change in
future should a heterogenous system be supported where the count/masks
are not the same across all CPUs (the current code is also incorrect
for this scenario - current_cpu_data here would not necessarily be
correct for the CPU that the target task will execute on).
Signed-off-by: Alex Smith <alex.smith@imgtec.com>
Reviewed-by: Paul Burton <paul.burton@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/6879/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
The lock is taken in the raw irq path and therefore a rawlock should be
used instead of a normal spinlock.
While here I drop the export symbol on that variable since there are no
other users.
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: linux-mips@linux-mips.org
Cc: Hua Yan <yanh@lemote.com>
Cc: Huacai Chen <chenhc@lemote.com>
Cc: Alex Smith <alex.smith@imgtec.com>
Cc: Hongliang Tao <taohl@lemote.com>
Cc: Wu Zhangjin <wuzhangjin@gmail.com>
Patchwork: https://patchwork.linux-mips.org/patch/6936/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
A kernel build with binutils 2.24 is going to emit warnings like
CC kernel/sys.o
{standard input}: Assembler messages:
{standard input}:701: Warning: the 32-bit MIPS architecture does not support the `mdmx' extension
{standard input}:701: Warning: the `mdmx' extension requires 64-bit FPRs
{standard input}:701: Warning: the `mips3d' extension requires MIPS32 revision 2 or greater
{standard input}:701: Warning: the `mips3d' extension requires 64-bit FPRs
for almost every file. This is caused by changes to gas' interpretation
of .set semantics. Fixed by explicitly disabling MIPS3D and MDMX for
Sibyte builds.
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Commit 6130f5315e "switch vmsplice_to_user() to copy_page_to_iter()" in
v3.15-rc1 broke vmsplice(2).
This patch fixes two bugs:
- count is not initialized to a proper value, which resulted in no data
being copied
- if rw_copy_check_uvector() returns negative then the iov might be leaked.
Tested OK.
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
If we try to perform a kexec when the machine is in ST (Single-Threaded) mode
(ppc64_cpu --smt=off), the kexec operation doesn't succeed properly, and we
get the following messages during boot:
[ 0.089866] POWER8 performance monitor hardware support registered
[ 0.089985] power8-pmu: PMAO restore workaround active.
[ 5.095419] Processor 1 is stuck.
[ 10.097933] Processor 2 is stuck.
[ 15.100480] Processor 3 is stuck.
[ 20.102982] Processor 4 is stuck.
[ 25.105489] Processor 5 is stuck.
[ 30.108005] Processor 6 is stuck.
[ 35.110518] Processor 7 is stuck.
[ 40.113369] Processor 9 is stuck.
[ 45.115879] Processor 10 is stuck.
[ 50.118389] Processor 11 is stuck.
[ 55.120904] Processor 12 is stuck.
[ 60.123425] Processor 13 is stuck.
[ 65.125970] Processor 14 is stuck.
[ 70.128495] Processor 15 is stuck.
[ 75.131316] Processor 17 is stuck.
Note that only the sibling threads are stuck, while the primary threads (0, 8,
16 etc) boot just fine. Looking closer at the previous step of kexec, we observe
that kexec tries to wakeup (bring online) the sibling threads of all the cores,
before performing kexec:
[ 9464.131231] Starting new kernel
[ 9464.148507] kexec: Waking offline cpu 1.
[ 9464.148552] kexec: Waking offline cpu 2.
[ 9464.148600] kexec: Waking offline cpu 3.
[ 9464.148636] kexec: Waking offline cpu 4.
[ 9464.148671] kexec: Waking offline cpu 5.
[ 9464.148708] kexec: Waking offline cpu 6.
[ 9464.148743] kexec: Waking offline cpu 7.
[ 9464.148779] kexec: Waking offline cpu 9.
[ 9464.148815] kexec: Waking offline cpu 10.
[ 9464.148851] kexec: Waking offline cpu 11.
[ 9464.148887] kexec: Waking offline cpu 12.
[ 9464.148922] kexec: Waking offline cpu 13.
[ 9464.148958] kexec: Waking offline cpu 14.
[ 9464.148994] kexec: Waking offline cpu 15.
[ 9464.149030] kexec: Waking offline cpu 17.
Instrumenting this piece of code revealed that the cpu_up() operation actually
fails with -EBUSY. Thus, only the primary threads of all the cores are online
during kexec, and hence this is a sure-shot receipe for disaster, as explained
in commit e8e5c2155b (powerpc/kexec: Fix orphaned offline CPUs across kexec),
as well as in the comment above wake_offline_cpus().
It turns out that cpu_up() was returning -EBUSY because the variable
'cpu_hotplug_disabled' was set to 1; and this disabling of CPU hotplug was done
by migrate_to_reboot_cpu() inside kernel_kexec().
Now, migrate_to_reboot_cpu() was originally written with the assumption that
any further code will not need to perform CPU hotplug, since we are anyway in
the reboot path. However, kexec is clearly not such a case, since we depend on
onlining CPUs, atleast on powerpc.
So re-enable cpu-hotplug after returning from migrate_to_reboot_cpu() in the
kexec path, to fix this regression in kexec on powerpc.
Also, wrap the cpu_up() in powerpc kexec code within a WARN_ON(), so that we
can catch such issues more easily in the future.
Fixes: c97102ba96 (kexec: migrate to reboot cpu)
Cc: stable@vger.kernel.org
Signed-off-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
With binutils 2.24, various 64 bit builds fail with relocation errors
such as
arch/powerpc/kernel/built-in.o: In function `exc_debug_crit_book3e':
(.text+0x165ee): relocation truncated to fit: R_PPC64_ADDR16_HI
against symbol `interrupt_base_book3e' defined in .text section
in arch/powerpc/kernel/built-in.o
arch/powerpc/kernel/built-in.o: In function `exc_debug_crit_book3e':
(.text+0x16602): relocation truncated to fit: R_PPC64_ADDR16_HI
against symbol `interrupt_end_book3e' defined in .text section
in arch/powerpc/kernel/built-in.o
The assembler maintainer says:
I changed the ABI, something that had to be done but unfortunately
happens to break the booke kernel code. When building up a 64-bit
value with lis, ori, shl, oris, ori or similar sequences, you now
should use @high and @higha in place of @h and @ha. @h and @ha
(and their associated relocs R_PPC64_ADDR16_HI and R_PPC64_ADDR16_HA)
now report overflow if the value is out of 32-bit signed range.
ie. @h and @ha assume you're building a 32-bit value. This is needed
to report out-of-range -mcmodel=medium toc pointer offsets in @toc@h
and @toc@ha expressions, and for consistency I did the same for all
other @h and @ha relocs.
Replacing @h with @high in one strategic location fixes the relocation
errors. This has to be done conditionally since the assembler either
supports @h or @high but not both.
Cc: <stable@vger.kernel.org>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Fixes from Chris, all cc: stable.
* tag 'drm-intel-fixes-2014-05-27' of git://anongit.freedesktop.org/drm-intel:
drm/i915: Prevent negative relocation deltas from wrapping
drm/i915: Only copy back the modified fields to userspace from execbuffer
drm/i915: Fix dynamic allocation of physical handles
Pull virtio_blk fix from Jens Axboe:
"There's a start/stop queue race in virtio_blk, which causes stalls and
erratic behaviour for some. I've had this queued up for 3.16 for a
while, but I think we should push it into the current series as well.
So I cherry picked the commit and added a stable marker as well, so it
can propagate down"
* 'for-linus' of git://git.kernel.dk/linux-block:
virtio_blk: fix race between start and stop queue
Thomas Gleixner