Jarkko Sakkinen [Tue, 15 Sep 2015 17:05:40 +0000 (20:05 +0300)]
tpm, tpm_crb: fix unaligned read of the command buffer address
The command buffer address must be read with exactly two 32-bit reads.
Otherwise, on some HW platforms, it seems that HW will abort the read
operation, which causes CPU to fill the read bytes with 1's. Therefore,
we cannot rely on memcpy_fromio() but must call ioread32() two times
instead.
Also, this matches the PC Client Platform TPM Profile specification,
which defines command buffer address with two 32-bit fields.
Cc: stable@kernel.org Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com> Reviewed-by: Peter Huewe <peterhuewe@gmx.de> Signed-off-by: Peter Huewe <peterhuewe@gmx.de>
vTPM: fix memory allocation flag for rtce buffer at kernel boot
At ibm vtpm initialzation, tpm_ibmvtpm_probe() registers its interrupt
handler, ibmvtpm_interrupt, which calls ibmvtpm_crq_process to allocate
memory for rtce buffer. The current code uses 'GFP_KERNEL' as the
type of kernel memory allocation, which resulted a warning at
kernel/lockdep.c. This patch uses 'GFP_ATOMIC' instead so that the
allocation is high-priority and does not sleep.
Cc: stable@kernel.org Signed-off-by: Hon Ching(Vicky) Lo <honclo@linux.vnet.ibm.com> Signed-off-by: Peter Huewe <peterhuewe@gmx.de>
tpm: Allow compile test of GPIO consumers if !GPIOLIB
The GPIO subsystem provides dummy GPIO consumer functions if GPIOLIB is
not enabled. Hence drivers that depend on GPIOLIB, but use GPIO consumer
functionality only, can still be compiled if GPIOLIB is not enabled.
Relax the dependency on GPIOLIB if COMPILE_TEST is enabled, where
appropriate.
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org> Acked-by: Linus Walleij <linus.walleij@linaro.org> Reviewed-by: Peter Huewe <peterhuewe@gmx.de> Signed-off-by: Peter Huewe <peterhuewe@gmx.de>
Linus Torvalds [Sun, 4 Oct 2015 15:31:13 +0000 (16:31 +0100)]
Merge branch 'strscpy' of git://git.kernel.org/pub/scm/linux/kernel/git/cmetcalf/linux-tile
Pull strscpy string copy function implementation from Chris Metcalf.
Chris sent this during the merge window, but I waffled back and forth on
the pull request, which is why it's going in only now.
The new "strscpy()" function is definitely easier to use and more secure
than either strncpy() or strlcpy(), both of which are horrible nasty
interfaces that have serious and irredeemable problems.
strncpy() has a useless return value, and doesn't NUL-terminate an
overlong result. To make matters worse, it pads a short result with
zeroes, which is a performance disaster if you have big buffers.
strlcpy(), by contrast, is a mis-designed "fix" for strlcpy(), lacking
the insane NUL padding, but having a differently broken return value
which returns the original length of the source string. Which means
that it will read characters past the count from the source buffer, and
you have to trust the source to be properly terminated. It also makes
error handling fragile, since the test for overflow is unnecessarily
subtle.
strscpy() avoids both these problems, guaranteeing the NUL termination
(but not excessive padding) if the destination size wasn't zero, and
making the overflow condition very obvious by returning -E2BIG. It also
doesn't read past the size of the source, and can thus be used for
untrusted source data too.
So why did I waffle about this for so long?
Every time we introduce a new-and-improved interface, people start doing
these interminable series of trivial conversion patches.
And every time that happens, somebody does some silly mistake, and the
conversion patch to the improved interface actually makes things worse.
Because the patch is mindnumbing and trivial, nobody has the attention
span to look at it carefully, and it's usually done over large swatches
of source code which means that not every conversion gets tested.
So I'm pulling the strscpy() support because it *is* a better interface.
But I will refuse to pull mindless conversion patches. Use this in
places where it makes sense, but don't do trivial patches to fix things
that aren't actually known to be broken.
* 'strscpy' of git://git.kernel.org/pub/scm/linux/kernel/git/cmetcalf/linux-tile:
tile: use global strscpy() rather than private copy
string: provide strscpy()
Make asm/word-at-a-time.h available on all architectures
Linus Torvalds [Sun, 4 Oct 2015 10:47:28 +0000 (11:47 +0100)]
Merge tag 'md/4.3-fixes' of git://neil.brown.name/md
Pull md fixes from Neil Brown:
"Assorted fixes for md in 4.3-rc.
Two tagged for -stable, and one is really a cleanup to match and
improve kmemcache interface.
* tag 'md/4.3-fixes' of git://neil.brown.name/md:
md/bitmap: don't pass -1 to bitmap_storage_alloc.
md/raid1: Avoid raid1 resync getting stuck
md: drop null test before destroy functions
md: clear CHANGE_PENDING in readonly array
md/raid0: apply base queue limits *before* disk_stack_limits
md/raid5: don't index beyond end of array in need_this_block().
raid5: update analysis state for failed stripe
md: wait for pending superblock updates before switching to read-only
Linus Torvalds [Sun, 4 Oct 2015 10:41:58 +0000 (11:41 +0100)]
Merge branch 'upstream' of git://git.linux-mips.org/pub/scm/ralf/upstream-linus
Pull MIPS updates from Ralf Baechle:
"This week's round of MIPS fixes:
- Fix JZ4740 build
- Fix fallback to GFP_DMA
- FP seccomp in case of ENOSYS
- Fix bootmem panic
- A number of FP and CPS fixes
- Wire up new syscalls
- Make sure BPF assembler objects can properly be disassembled
- Fix BPF assembler code for MIPS I"
* 'upstream' of git://git.linux-mips.org/pub/scm/ralf/upstream-linus:
MIPS: scall: Always run the seccomp syscall filters
MIPS: Octeon: Fix kernel panic on startup from memory corruption
MIPS: Fix R2300 FP context switch handling
MIPS: Fix octeon FP context switch handling
MIPS: BPF: Fix load delay slots.
MIPS: BPF: Do all exports of symbols with FEXPORT().
MIPS: Fix the build on jz4740 after removing the custom gpio.h
MIPS: CPS: #ifdef on CONFIG_MIPS_MT_SMP rather than CONFIG_MIPS_MT
MIPS: CPS: Don't include MT code in non-MT kernels.
MIPS: CPS: Stop dangling delay slot from has_mt.
MIPS: dma-default: Fix 32-bit fall back to GFP_DMA
MIPS: Wire up userfaultfd and membarrier syscalls.
Linus Torvalds [Sun, 4 Oct 2015 10:40:09 +0000 (11:40 +0100)]
Merge branch 'irq-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull irq fixes from Thomas Gleixner:
"This update contains:
- Fix for a long standing race affecting /proc/irq/NNN
- One line fix for ARM GICV3-ITS counting the wrong data
- Warning silencing in ARM GICV3-ITS. Another GCC trying to be
overly clever issue"
* 'irq-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
irqchip/gic-v3-its: Count additional LPIs for the aliased devices
irqchip/gic-v3-its: Silence warning when its_lpi_alloc_chunks gets inlined
genirq: Fix race in register_irq_proc()
MIPS: scall: Always run the seccomp syscall filters
The MIPS syscall handler code used to return -ENOSYS on invalid
syscalls. Whilst this is expected, it caused problems for seccomp
filters because the said filters never had the change to run since
the code returned -ENOSYS before triggering them. This caused
problems on the chromium testsuite for filters looking for invalid
syscalls. This has now changed and the seccomp filters are always
run even if the syscall is invalid. We return -ENOSYS once we
return from the seccomp filters. Moreover, similar codepaths have
been merged in the process which simplifies somewhat the overall
syscall code.
Linus Torvalds [Sat, 3 Oct 2015 14:53:05 +0000 (10:53 -0400)]
Merge branch 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 fixes from Ingo Molnar:
"Fixes all around the map: W+X kernel mapping fix, WCHAN fixes, two
build failure fixes for corner case configs, x32 header fix and a
speling fix"
* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/headers/uapi: Fix __BITS_PER_LONG value for x32 builds
x86/mm: Set NX on gap between __ex_table and rodata
x86/kexec: Fix kexec crash in syscall kexec_file_load()
x86/process: Unify 32bit and 64bit implementations of get_wchan()
x86/process: Add proper bound checks in 64bit get_wchan()
x86, efi, kasan: Fix build failure on !KASAN && KMEMCHECK=y kernels
x86/hyperv: Fix the build in the !CONFIG_KEXEC_CORE case
x86/cpufeatures: Correct spelling of the HWP_NOTIFY flag
Linus Torvalds [Sat, 3 Oct 2015 14:46:41 +0000 (10:46 -0400)]
Merge branch 'core-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull EFI fixes from Ingo Molnar:
"Two EFI fixes: one for x86, one for ARM, fixing a boot crash bug that
can trigger under newer EFI firmware"
* 'core-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
arm64/efi: Fix boot crash by not padding between EFI_MEMORY_RUNTIME regions
x86/efi: Fix boot crash by mapping EFI memmap entries bottom-up at runtime, instead of top-down
Linus Torvalds [Sat, 3 Oct 2015 14:39:31 +0000 (10:39 -0400)]
Merge branch 'drm-fixes' of git://people.freedesktop.org/~airlied/linux
Pull drm fixes from Dave Airlie:
"Bunch of fixes all over the place, all pretty small: amdgpu, i915,
exynos, one qxl and one vmwgfx.
There is also a bunch of mst fixes, I left some cleanups in the series
as I didn't think it was worth splitting up the tested series"
* 'drm-fixes' of git://people.freedesktop.org/~airlied/linux: (37 commits)
drm/dp/mst: add some defines for logical/physical ports
drm/dp/mst: drop cancel work sync in the mstb destroy path (v2)
drm/dp/mst: split connector registration into two parts (v2)
drm/dp/mst: update the link_address_sent before sending the link address (v3)
drm/dp/mst: fixup handling hotplug on port removal.
drm/dp/mst: don't pass port into the path builder function
drm/radeon: drop radeon_fb_helper_set_par
drm: handle cursor_set2 in restore_fbdev_mode
drm/exynos: Staticize local function in exynos_drm_gem.c
drm/exynos: fimd: actually disable dp clock
drm/exynos: dp: remove suspend/resume functions
drm/qxl: recreate the primary surface when the bo is not primary
drm/amdgpu: only print meaningful VM faults
drm/amdgpu/cgs: remove import_gpu_mem
drm/i915: Call non-locking version of drm_kms_helper_poll_enable(), v2
drm: Add a non-locking version of drm_kms_helper_poll_enable(), v2
drm/vmwgfx: Fix a command submission hang regression
drm/exynos: remove unused mode_fixup() code
drm/exynos: remove decon_mode_fixup()
drm/exynos: remove fimd_mode_fixup()
...
Linus Torvalds [Fri, 2 Oct 2015 21:53:25 +0000 (17:53 -0400)]
Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input
Pull input layer fixes from Dmitry Torokhov:
"Fixes for two recent regressions (in Synaptics PS/2 and uinput
drivers) and some more driver fixups"
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input:
Revert "Input: synaptics - fix handling of disabling gesture mode"
Input: psmouse - fix data race in __ps2_command
Input: elan_i2c - add all valid ic type for i2c/smbus
Input: zhenhua - ensure we have BITREVERSE
Input: omap4-keypad - fix memory leak
Input: serio - fix blocking of parport
Input: uinput - fix crash when using ABS events
Input: elan_i2c - expand maximum product_id form 0xFF to 0xFFFF
Input: elan_i2c - add ic type 0x03
Input: elan_i2c - don't require known iap version
Input: imx6ul_tsc - fix controller name
Input: imx6ul_tsc - use the preferred method for kzalloc()
Input: imx6ul_tsc - check for negative return value
Input: imx6ul_tsc - propagate the errors
Input: walkera0701 - fix abs() calculations on 64 bit values
Input: mms114 - remove unneded semicolons
Input: pm8941-pwrkey - remove unneded semicolon
Input: fix typo in MT documentation
Input: cyapa - fix address of Gen3 devices in device tree documentation
Linus Torvalds [Fri, 2 Oct 2015 18:51:46 +0000 (14:51 -0400)]
Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/geert/linux-m68k
Pull m68k updates from Geert Uytterhoeven:
"Summary:
- Fix for accidental modification of arguments of syscall functions
- Wire up new syscalls
- Update defconfigs"
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/geert/linux-m68k:
m68k/defconfig: Update defconfigs for v4.3-rc1
m68k: Define asmlinkage_protect
m68k: Wire up membarrier
m68k: Wire up userfaultfd
m68k: Wire up direct socket calls
Marc Zyngier [Fri, 2 Oct 2015 15:44:06 +0000 (16:44 +0100)]
irqchip/gic-v3-its: Count additional LPIs for the aliased devices
When configuring the interrupt mapping for a new device, we
iterate over all the possible aliases to account for their
maximum MSI allocation. This was introduced by e8137f4f5088
("irqchip: gicv3-its: Iterate over PCI aliases to generate ITS configuration").
Turns out that the code doing that is a bit braindead, and repeatedly
accounts for the same device over and over.
Fix this by counting the actual alias that is passed to us by the
core code.
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Cc: linux-arm-kernel@lists.infradead.org Cc: Alex Shi <alex.shi@linaro.org> Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org> Cc: David Daney <ddaney.cavm@gmail.com> Cc: Jason Cooper <jason@lakedaemon.net> Link: http://lkml.kernel.org/r/1443800646-8074-3-git-send-email-marc.zyngier@arm.com Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Marc Zyngier [Fri, 2 Oct 2015 15:44:05 +0000 (16:44 +0100)]
irqchip/gic-v3-its: Silence warning when its_lpi_alloc_chunks gets inlined
More agressive inlining in recent versions of GCC have uncovered
a new set of warnings:
drivers/irqchip/irq-gic-v3-its.c: In function its_msi_prepare:
drivers/irqchip/irq-gic-v3-its.c:1148:26: warning: lpi_base may be used
uninitialized in this function [-Wmaybe-uninitialized]
dev->event_map.lpi_base = lpi_base;
^
drivers/irqchip/irq-gic-v3-its.c:1116:6: note: lpi_base was declared here
int lpi_base;
^
drivers/irqchip/irq-gic-v3-its.c:1149:25: warning: nr_lpis may be used
uninitialized in this function [-Wmaybe-uninitialized]
dev->event_map.nr_lpis = nr_lpis;
^
drivers/irqchip/irq-gic-v3-its.c:1117:6: note: nr_lpis was declared here
int nr_lpis;
^
The warning is fairly benign (there is no code path that could
actually use uninitialized variables), but let's silence it anyway
by zeroing the variables on the error path.
Reported-by: Alex Shi <alex.shi@linaro.org> Tested-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Cc: linux-arm-kernel@lists.infradead.org Cc: David Daney <ddaney.cavm@gmail.com> Cc: Jason Cooper <jason@lakedaemon.net> Link: http://lkml.kernel.org/r/1443800646-8074-2-git-send-email-marc.zyngier@arm.com Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Linus Torvalds [Fri, 2 Oct 2015 18:46:15 +0000 (14:46 -0400)]
Merge tag 'dmaengine-fix-4.3-rc4' of git://git.infradead.org/users/vkoul/slave-dma
Pull dmaengine fixes from Vinod Koul:
"This contains fixes spread throughout the drivers, and also fixes one
more instance of privatecnt in dmaengine.
Driver fixes summary:
- bunch of pxa_dma fixes for reuse of descriptor issue, residue and
no-requestor
- odd fixes in xgene, idma, sun4i and zxdma
- at_xdmac fixes for cleaning descriptor and block addr mode"
* tag 'dmaengine-fix-4.3-rc4' of git://git.infradead.org/users/vkoul/slave-dma:
dmaengine: pxa_dma: fix residue corner case
dmaengine: pxa_dma: fix the no-requestor case
dmaengine: zxdma: Fix off-by-one for testing valid pchan request
dmaengine: at_xdmac: clean used descriptor
dmaengine: at_xdmac: change block increment addressing mode
dmaengine: dw: properly read DWC_PARAMS register
dmaengine: xgene-dma: Fix overwritting DMA tx ring
dmaengine: fix balance of privatecnt
dmaengine: sun4i: fix unsafe list iteration
dmaengine: idma64: improve residue estimation
dmaengine: xgene-dma: fix handling xgene_dma_get_ring_size result
dmaengine: pxa_dma: fix initial list move
Linus Torvalds [Fri, 2 Oct 2015 18:40:57 +0000 (14:40 -0400)]
Merge branch 'for-linus' of git://git.kernel.dk/linux-block
Pull block fixes from Jens Axboe:
"Another week, another round of fixes.
These have been brewing for a bit and in various iterations, but I
feel pretty comfortable about the quality of them. They fix real
issues. The pull request is mostly blk-mq related, and the only one
not fixing a real bug, is the tag iterator abstraction from Christoph.
But it's pretty trivial, and we'll need it for another fix soon.
Apart from the blk-mq fixes, there's an NVMe affinity fix from Keith,
and a single fix for xen-blkback from Roger fixing failure to free
requests on disconnect"
* 'for-linus' of git://git.kernel.dk/linux-block:
blk-mq: factor out a helper to iterate all tags for a request_queue
blk-mq: fix racy updates of rq->errors
blk-mq: fix deadlock when reading cpu_list
blk-mq: avoid inserting requests before establishing new mapping
blk-mq: fix q->mq_usage_counter access race
blk-mq: Fix use after of free q->mq_map
blk-mq: fix sysfs registration/unregistration race
blk-mq: avoid setting hctx->tags->cpumask before allocation
NVMe: Set affinity after allocating request queues
xen/blkback: free requests on disconnection
Dmitry Torokhov [Fri, 2 Oct 2015 17:31:32 +0000 (10:31 -0700)]
Revert "Input: synaptics - fix handling of disabling gesture mode"
This reverts commit e51e38494a8ecc18650efb0c840600637891de2c: we
actually do want the device to work in extended W mode, as this is the
mode that allows us receiving multiple contact information.
Matt Bennett [Wed, 30 Sep 2015 04:40:42 +0000 (17:40 +1300)]
MIPS: Octeon: Fix kernel panic on startup from memory corruption
During development it was found that a number of builds would panic
during the kernel init process, more specifically in 'delayed_fput()'.
The panic showed the kernel trying to access a memory address of
'0xb7fdc00' while traversing the 'delayed_fput_list' structure.
Comparing this memory address to the value of the pointer used on
builds that did not panic confirmed that the pointer on crashing
builds must have been corrupted at some stage earlier in the init
process.
By traversing the list earlier and earlier in the code it was found
that 'plat_mem_setup()' was responsible for corrupting the list.
Specifically the line:
Where 'new_ent_addr'=0x4800000 (the address of 'delayed_fput_list')
and the second argument (size)=0xb7fdc00 (the address causing the
kernel panic). The job of this part of 'plat_mem_setup()' is to
allocate chunks of memory for the kernel to use. At the start of
each chunk of memory the size of the chunk is written, hence the
value 0xb7fdc00 is written onto memory at 0x4800000, therefore the
kernel panics when it goes back to access 'delayed_fput_list' later
on in the initialisation process.
On builds that were not crashing it was found that the compiler had
placed 'delayed_fput_list' at 0x4800008, meaning it wasn't corrupted
(but something else in memory was overwritten).
As can be seen in the first function call above the code begins to
allocate chunks of memory beginning from the symbol '__init_end'.
The MIPS linker script (vmlinux.lds.S) however defines the .bss
section to begin after '__init_end'. Therefore memory within the
.bss section is allocated to the kernel to use (System.map shows
'delayed_fput_list' and other kernel structures to be in .bss).
To stop the kernel panic (and the .bss section being corrupted)
memory should begin being allocated from the symbol '_end'.
Signed-off-by: Matt Bennett <matt.bennett@alliedtelesis.co.nz> Acked-by: David Daney <david.daney@cavium.com> Cc: linux-mips@linux-mips.org Cc: aleksey.makarov@auriga.com
Patchwork: https://patchwork.linux-mips.org/patch/11251/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Paul Burton [Mon, 21 Sep 2015 17:07:42 +0000 (10:07 -0700)]
MIPS: Fix R2300 FP context switch handling
Commit 1a3d59579b9f ("MIPS: Tidy up FPU context switching") removed FP
context saving from the asm-written resume function in favour of reusing
existing code to perform the same task. However it only removed the FP
context saving code from the r4k_switch.S implementation of resume.
Remove it from the r2300_switch.S implementation too in order to prevent
attempting to save the FP context twice, which would likely lead to an
exception from the second save because the FPU had already been disabled
by the first save.
This patch has only been build tested, using rbtx49xx_defconfig.
Fixes: 1a3d59579b9f ("MIPS: Tidy up FPU context switching") Signed-off-by: Paul Burton <paul.burton@imgtec.com> Cc: linux-mips@linux-mips.org Cc: Maciej W. Rozycki <macro@linux-mips.org> Cc: linux-kernel@vger.kernel.org Cc: Manuel Lauss <manuel.lauss@gmail.com>
Patchwork: https://patchwork.linux-mips.org/patch/11167/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Paul Burton [Mon, 21 Sep 2015 17:07:41 +0000 (10:07 -0700)]
MIPS: Fix octeon FP context switch handling
Commit 1a3d59579b9f ("MIPS: Tidy up FPU context switching") removed FP
context saving from the asm-written resume function in favour of reusing
existing code to perform the same task. However it only removed the FP
context saving code from the r4k_switch.S implementation of resume.
Octeon uses its own implementation in octeon_switch.S, so remove FP
context saving there too in order to prevent attempting to save context
twice. That formerly led to an exception from the second save as follows
because the FPU had already been disabled by the first save:
Linus Torvalds [Fri, 2 Oct 2015 12:03:04 +0000 (08:03 -0400)]
Merge tag 'mmc-v4.3-rc3' of git://git.linaro.org/people/ulf.hansson/mmc
Pull MMC fixes from Ulf Hansson:
"Here are some mmc fixes intended for v4.3 rc4:
MMC core:
- Allow users of mmc_of_parse() to succeed when CONFIG_GPIOLIB is
unset
- Prevent infinite loop of re-tuning for CRC-errors for CMD19 and
CMD21
* tag 'mmc-v4.3-rc3' of git://git.linaro.org/people/ulf.hansson/mmc:
mmc: core: fix dead loop of mmc_retune
mmc: pxamci: fix card detect with slot-gpio API
mmc: sunxi: Fix clk-delay settings
mmc: core: Don't return an error for CD/WP GPIOs when GPIOLIB is unset
Linus Torvalds [Fri, 2 Oct 2015 11:59:29 +0000 (07:59 -0400)]
Merge git://git.infradead.org/intel-iommu
Pull IOVA fixes from David Woodhouse:
"The main fix here is the first one, fixing the over-allocation of
size-aligned requests. The other patches simply make the existing
IOVA code available to users other than the Intel VT-d driver, with no
functional change.
I concede the latter really *should* have been submitted during the
merge window, but since it's basically risk-free and people are
waiting to build on top of it and it's my fault I didn't get it in, I
(and they) would be grateful if you'd take it"
* git://git.infradead.org/intel-iommu:
iommu: Make the iova library a module
iommu: iova: Export symbols
iommu: iova: Move iova cache management to the iova library
iommu/iova: Avoid over-allocating when size-aligned
This is because when using function graph tracer, if the traced
function return value is in multi regs ([x0-x7]), return_to_handler
may corrupt them. So in return_to_handler, the parameter regs should
be protected properly.
Cc: <stable@vger.kernel.org> # 3.18+ Signed-off-by: Li Bin <huawei.libin@huawei.com> Acked-by: AKASHI Takahiro <takahiro.akashi@linaro.org> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Ralf Baechle [Fri, 2 Oct 2015 07:48:57 +0000 (09:48 +0200)]
MIPS: BPF: Fix load delay slots.
The entire bpf_jit_asm.S is written in noreorder mode because "we know
better" according to a comment. This also prevented the assembler from
throwing in the required NOPs for MIPS I processors which have no
load-use interlock, thus the load's consumer might end up using the
old value of the register from prior to the load.
Fixed by putting the assembler in reorder mode for just the affected
load instructions. This is not enough for gas to actually try to be
clever by looking at the next instruction and inserting a nop only
when needed but as the comment said "we know better", so getting gas
to unconditionally emit a NOP is just right in this case and prevents
adding further ifdefery.
Ben Hutchings [Thu, 1 Oct 2015 00:40:43 +0000 (01:40 +0100)]
x86/headers/uapi: Fix __BITS_PER_LONG value for x32 builds
On x32, gcc predefines __x86_64__ but long is only 32-bit. Use
__ILP32__ to distinguish x32.
Fixes this compiler error in perf:
tools/include/asm-generic/bitops/__ffs.h: In function '__ffs':
tools/include/asm-generic/bitops/__ffs.h:19:8: error: right shift count >= width of type [-Werror=shift-count-overflow]
word >>= 32;
^
This isn't sufficient to build perf for x32, though.
Signed-off-by: Ben Hutchings <ben@decadent.org.uk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-kernel@vger.kernel.org Link: http://lkml.kernel.org/r/1443660043.2730.15.camel@decadent.org.uk Signed-off-by: Ingo Molnar <mingo@kernel.org>
NeilBrown [Thu, 1 Oct 2015 06:03:38 +0000 (16:03 +1000)]
md/bitmap: don't pass -1 to bitmap_storage_alloc.
Passing -1 to bitmap_storage_alloc() causes page->index to be set to
-1, which is quite problematic.
So only pass ->cluster_slot if mddev_is_clustered().
Fixes: b97e92574c0b ("Use separate bitmaps for each nodes in the cluster") Cc: stable@vger.kernel.org (v4.1+) Signed-off-by: NeilBrown <neilb@suse.com>
close_sync() needs to set conf->next_resync to a large, but safe value
below MaxSector and use it to determine whether or not to set
start_next_window in wait_barrier()
Shaohua Li [Fri, 18 Sep 2015 17:20:12 +0000 (10:20 -0700)]
md: clear CHANGE_PENDING in readonly array
If faulty disks of an array are more than allowed degraded number, the
array enters error handling. It will be marked as read-only with
MD_CHANGE_PENDING/RECOVERY_NEEDED set. But currently recovery doesn't
clear CHANGE_PENDING bit for read-only array. If MD_CHANGE_PENDING is
set for a raid5 array, all returned IO will be hold on a list till the
bit is clear. But recovery nevery clears this bit, the IO is always in
pending state and nevery finish. This has bad effects like upper layer
can't get an IO error and the array can't be stopped.
Fixes: c3cce6cda162 ("md/raid5: ensure device failure recorded before write request returns.") Signed-off-by: Shaohua Li <shli@fb.com> Signed-off-by: NeilBrown <neilb@suse.com>
md/raid0: apply base queue limits *before* disk_stack_limits
Calling e.g. blk_queue_max_hw_sectors() after calls to
disk_stack_limits() discards the settings determined by
disk_stack_limits().
So we need to make those calls first.
Fixes: 199dc6ed5179 ("md/raid0: update queue parameter in a safer location.") Cc: stable@vger.kernel.org (v2.6.35+ - please apply with 199dc6ed5179). Reported-by: Jes Sorensen <Jes.Sorensen@redhat.com> Signed-off-by: NeilBrown <neilb@suse.com>
md/raid5: don't index beyond end of array in need_this_block().
When need_this_block probably shouldn't be called when there
are more than 2 failed devices, we really don't want it to try
indexing beyond the end of the failed_num[] of fdev[] arrays.
So limit the loops to at most 2 iterations.
Reported-by: Shaohua Li <shli@fb.com> Signed-off-by: NeilBrown <neilb@suse.de>
Shaohua Li [Fri, 18 Sep 2015 17:20:13 +0000 (10:20 -0700)]
raid5: update analysis state for failed stripe
handle_failed_stripe() makes the stripe fail, eg, all IO will return
with a failure, but it doesn't update stripe_head_state. Later
handle_stripe() has special handling for raid6 for handle_stripe_fill().
That check before handle_stripe_fill() doesn't skip the failed stripe
and we get a kernel crash in need_this_block. This patch clear the
analysis state to make sure no functions wrongly called after
handle_failed_stripe()
Signed-off-by: Shaohua Li <shli@fb.com> Signed-off-by: NeilBrown <neilb@suse.com>
md: wait for pending superblock updates before switching to read-only
If a superblock update is pending, wait for it to complete before
letting md_set_readonly() switch to readonly.
Otherwise we might lose important information about a device having
failed.
For external arrays, waiting for superblock updates can wait on
user-space, so in that case, just return an error.
Reported-and-tested-by: Shaohua Li <shli@fb.com> Signed-off-by: NeilBrown <neilb@suse.com>
Stephen Smalley [Thu, 1 Oct 2015 13:04:22 +0000 (09:04 -0400)]
x86/mm: Set NX on gap between __ex_table and rodata
Unused space between the end of __ex_table and the start of
rodata can be left W+x in the kernel page tables. Extend the
setting of the NX bit to cover this gap by starting from
text_end rather than rodata_start.
Before:
---[ High Kernel Mapping ]---
0xffffffff80000000-0xffffffff81000000 16M pmd
0xffffffff81000000-0xffffffff81600000 6M ro PSE GLB x pmd
0xffffffff81600000-0xffffffff81754000 1360K ro GLB x pte
0xffffffff81754000-0xffffffff81800000 688K RW GLB x pte
0xffffffff81800000-0xffffffff81a00000 2M ro PSE GLB NX pmd
0xffffffff81a00000-0xffffffff81b3b000 1260K ro GLB NX pte
0xffffffff81b3b000-0xffffffff82000000 4884K RW GLB NX pte
0xffffffff82000000-0xffffffff82200000 2M RW PSE GLB NX pmd
0xffffffff82200000-0xffffffffa0000000 478M pmd
After:
---[ High Kernel Mapping ]---
0xffffffff80000000-0xffffffff81000000 16M pmd
0xffffffff81000000-0xffffffff81600000 6M ro PSE GLB x pmd
0xffffffff81600000-0xffffffff81754000 1360K ro GLB x pte
0xffffffff81754000-0xffffffff81800000 688K RW GLB NX pte
0xffffffff81800000-0xffffffff81a00000 2M ro PSE GLB NX pmd
0xffffffff81a00000-0xffffffff81b3b000 1260K ro GLB NX pte
0xffffffff81b3b000-0xffffffff82000000 4884K RW GLB NX pte
0xffffffff82000000-0xffffffff82200000 2M RW PSE GLB NX pmd
0xffffffff82200000-0xffffffffa0000000 478M pmd
Signed-off-by: Stephen Smalley <sds@tycho.nsa.gov> Acked-by: Kees Cook <keescook@chromium.org> Cc: <stable@vger.kernel.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-kernel@vger.kernel.org Link: http://lkml.kernel.org/r/1443704662-3138-1-git-send-email-sds@tycho.nsa.gov Signed-off-by: Ingo Molnar <mingo@kernel.org>
x86/kexec: Fix kexec crash in syscall kexec_file_load()
The original bug is a page fault crash that sometimes happens
on big machines when preparing ELF headers:
BUG: unable to handle kernel paging request at ffffc90613fc9000
IP: [<ffffffff8103d645>] prepare_elf64_ram_headers_callback+0x165/0x260
The bug is caused by us under-counting the number of memory ranges
and subsequently not allocating enough ELF header space for them.
The bug is typically masked on smaller systems, because the ELF header
allocation is rounded up to the next page.
This patch modifies the code in fill_up_crash_elf_data() by using
walk_system_ram_res() instead of walk_system_ram_range() to correctly
count the max number of crash memory ranges. That's because the
walk_system_ram_range() filters out small memory regions that
reside in the same page, but walk_system_ram_res() does not.
Here's how I found the bug:
After tracing prepare_elf64_headers() and prepare_elf64_ram_headers_callback(),
the code uses walk_system_ram_res() to fill-in crash memory regions information
to the program header, so it counts those small memory regions that
reside in a page area.
But, when the kernel was using walk_system_ram_range() in
fill_up_crash_elf_data() to count the number of crash memory regions,
it filters out small regions.
I printed those small memory regions, for example:
kexec: Get nr_ram ranges. vaddr=0xffff880077592258 paddr=0x77592258, sz=0xdc0
Based on the code in walk_system_ram_range(), this memory region
will be filtered out:
So, the max_nr_ranges that's counted by the kernel doesn't include
small memory regions - causing us to under-allocate the required space.
That causes the page fault crash that happens in a later code path
when preparing ELF headers.
This bug is not easy to reproduce on small machines that have few
CPUs, because the allocated page aligned ELF buffer has more free
space to cover those small memory regions' PT_LOAD headers.
Signed-off-by: Lee, Chun-Yi <jlee@suse.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Baoquan He <bhe@redhat.com> Cc: Jiang Liu <jiang.liu@linux.intel.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stephen Rothwell <sfr@canb.auug.org.au> Cc: Takashi Iwai <tiwai@suse.de> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Viresh Kumar <viresh.kumar@linaro.org> Cc: Vivek Goyal <vgoyal@redhat.com> Cc: kexec@lists.infradead.org Cc: linux-kernel@vger.kernel.org Cc: <stable@vger.kernel.org> Link: http://lkml.kernel.org/r/1443531537-29436-1-git-send-email-jlee@suse.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
we validate the mstb structs in the work function, and doing
that takes a reference. So we should never get here with the
work function running using the mstb device, only if the work
function hasn't run yet or is running for another mstb.
So we don't need to sync the work here, this was causing
lockdep spew as below.
[ +0.000160] =============================================
[ +0.000001] [ INFO: possible recursive locking detected ]
[ +0.000002] 3.10.0-320.el7.rhel72.stable.backport.3.x86_64.debug #1 Tainted: G W ------------
[ +0.000001] ---------------------------------------------
[ +0.000001] kworker/4:2/1262 is trying to acquire lock:
[ +0.000001] ((&mgr->work)){+.+.+.}, at: [<ffffffff810b29a5>] flush_work+0x5/0x2e0
[ +0.000007]
but task is already holding lock:
[ +0.000001] ((&mgr->work)){+.+.+.}, at: [<ffffffff810b57e4>] process_one_work+0x1b4/0x710
[ +0.000004]
other info that might help us debug this:
[ +0.000001] Possible unsafe locking scenario:
Dave Airlie [Wed, 16 Sep 2015 07:55:23 +0000 (17:55 +1000)]
drm/dp/mst: split connector registration into two parts (v2)
In order to cache the EDID properly for tiled displays, we
need to retrieve it before we register the connector with
userspace, otherwise userspace can call get resources
and try and get the edid before we've even cached it.
This fixes some problems when hotplugging mst monitors,
with X/mutter running. As mutter seems to get 0 modes
for one of the monitors in the tile.
v2: fix warning in radeon
handle tile setting in cached path rather than
get edid path.
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch> Cc: stable@vger.kernel.org Signed-off-by: Dave Airlie <airlied@redhat.com>
Alex Deucher [Wed, 30 Sep 2015 18:47:38 +0000 (14:47 -0400)]
drm/radeon: drop radeon_fb_helper_set_par
It was just a wrapper around drm_fb_helper_set_par that
called cursor_set2 in addition. Now that the core handles
this, drop this radeon specific version.
Signed-off-by: Alex Deucher <alexander.deucher@amd.com> Reviewed-by: Christian König <christian.koenig@amd.com> Reviewed-by: Michel Dänzer <michel.daenzer@amd.com> Signed-off-by: Dave Airlie <airlied@redhat.com>
Alex Deucher [Wed, 30 Sep 2015 18:47:37 +0000 (14:47 -0400)]
drm: handle cursor_set2 in restore_fbdev_mode
If a driver uses the cursor_set2 crtc callback rather than
cursor_set, use that. This fixes the fbdev helper for drivers
that use cursor_set2.
Signed-off-by: Alex Deucher <alexander.deucher@amd.com> Reviewed-by: Christian König <christian.koenig@amd.com> Reviewed-by: Michel Dänzer <michel.daenzer@amd.com> Signed-off-by: Dave Airlie <airlied@redhat.com>
Linus Torvalds [Fri, 2 Oct 2015 02:20:11 +0000 (22:20 -0400)]
Merge branch 'akpm' (patches from Andrew)
Merge misc fixes from Andrew Morton:
"12 fixes"
* emailed patches from Andrew Morton <akpm@linux-foundation.org>:
dmapool: fix overflow condition in pool_find_page()
thermal: avoid division by zero in power allocator
memcg: remove pcp_counter_lock
kprobes: use _do_fork() in samples to make them work again
drivers/input/joystick/Kconfig: zhenhua.c needs BITREVERSE
memcg: make mem_cgroup_read_stat() unsigned
memcg: fix dirty page migration
dax: fix NULL pointer in __dax_pmd_fault()
mm: hugetlbfs: skip shared VMAs when unmapping private pages to satisfy a fault
mm/slab: fix unexpected index mapping result of kmalloc_size(INDEX_NODE+1)
userfaultfd: remove kernel header include from uapi header
arch/x86/include/asm/efi.h: fix build failure
Linus Torvalds [Fri, 2 Oct 2015 02:06:40 +0000 (22:06 -0400)]
Merge tag 'pm+acpi-4.3-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm
Pull power management and ACPI fixes from Rafael Wysocki:
"These are fixes mostly, for a few changes made in this cycle (the
intel_idle driver, the OPP library, the ACPI EC driver, turbostat) and
for some issues that have just been discovered (ACPI PCI IRQ
management, PCI power management documentation, turbostat), with a
couple of cleanups on top of them.
Specifics:
- intel_idle driver fixup for the recently added Skylake chips
support (Len Brown).
- Operating Performance Points (OPP) library fix related to the
recently added support for new DT bindings and a fix for a typo in
a comment (Viresh Kumar, Stephen Boyd).
- ACPI EC driver fix for a recently introduced memory leak in an
error code path (Lv Zheng).
- ACPI PCI IRQ management fix for the issue where an ISA IRQ is
shared with a PCI device which requires it to be configured in a
different way and may cause an interrupt storm to happen as a
result with an extra ACPI SCI IRQ handling simplification on top of
it (Jiang Liu).
- Update of the PCI power management documentation that became
outdated and started to actively confuse the readers to make it
actually reflect the code (Rafael J Wysocki).
- turbostat fixes including an IVB Xeon regression fix (related to
the --debug command line option), Skylake adjustment for the TSC
running at a frequency that doesn't match the base one exactly, and
a Knights Landing quirk to account for the fact that it only
updates APERF and MPERF every 1024 clock cycles plus bumping up the
turbostat version number (Len Brown, Hubert Chrzaniuk)"
* tag 'pm+acpi-4.3-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
tools/power turbosat: update version number
tools/power turbostat: SKL: Adjust for TSC difference from base frequency
tools/power turbostat: KNL workaround for %Busy and Avg_MHz
tools/power turbostat: IVB Xeon: fix --debug regression
ACPI / PCI: Remove duplicated penalty on SCI IRQ
ACPI, PCI, irq: Do not share PCI IRQ with ISA IRQ
ACPI / EC: Fix a memory leak issue in acpi_ec_query()
PM / OPP: Fix typo modifcation -> modification
PCI / PM: Update runtime PM documentation for PCI devices
PM / OPP: of_property_count_u32_elems() can return errors
intel_idle: Skylake Client Support - updated
1) Fix regression in SKB partial checksum handling, from Pravin B
Shalar.
2) Fix VLAN inside of VXLAN handling in i40e driver, from Jesse
Brandeburg.
3) Cure softlockups during accept() in SCTP, from Karl Heiss.
4) MSG_PEEK should return multiple SKBs worth of data in AF_UNIX, from
Aaron Conole.
5) IPV6 erroneously ignores output interface specifier in lookup key for
route lookups, fix from David Ahern.
6) In Marvell DSA driver, forward unknown frames to CPU port, from
Andrew Lunn.
7) Mission flow flag initializations in some code paths, from David
Ahern.
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net:
net: Initialize flow flags in input path
net: dsa: fix preparation of a port STP update
testptp: Silence compiler warnings on ppc64
net/mlx4: Handle return codes in mlx4_qp_attach_common
dsa: mv88e6xxx: Enable forwarding for unknown to the CPU port
skbuff: Fix skb checksum partial check.
net: ipv6: Add RT6_LOOKUP_F_IFACE flag if oif is set
net sysfs: Print link speed as signed integer
bna: fix error handling
af_unix: return data from multiple SKBs on recv() with MSG_PEEK flag
af_unix: Convert the unix_sk macro to an inline function for type safety
net: sctp: Don't use 64 kilobyte lookup table for four elements
l2tp: protect tunnel->del_work by ref_count
net/ibm/emac: bump version numbers for correct work with ethtool
sctp: Prevent soft lockup when sctp_accept() is called during a timeout event
sctp: Whitespace fix
i40e/i40evf: check for stopped admin queue
i40e: fix VLAN inside VXLAN
r8169: fix handling rtl_readphy result
net: hisilicon: fix handling platform_get_irq result
Robin Murphy [Thu, 1 Oct 2015 22:37:19 +0000 (15:37 -0700)]
dmapool: fix overflow condition in pool_find_page()
If a DMA pool lies at the very top of the dma_addr_t range (as may
happen with an IOMMU involved), the calculated end address of the pool
wraps around to zero, and page lookup always fails.
Tweak the relevant calculation to be overflow-proof.
Signed-off-by: Robin Murphy <robin.murphy@arm.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Marek Szyprowski <m.szyprowski@samsung.com> Cc: Sumit Semwal <sumit.semwal@linaro.org> Cc: Sakari Ailus <sakari.ailus@iki.fi> Cc: Russell King <rmk+kernel@arm.linux.org.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Greg Thelen [Thu, 1 Oct 2015 22:37:13 +0000 (15:37 -0700)]
memcg: remove pcp_counter_lock
Commit 733a572e66d2 ("memcg: make mem_cgroup_read_{stat|event}() iterate
possible cpus instead of online") removed the last use of the per memcg
pcp_counter_lock but forgot to remove the variable.
Kill the vestigial variable.
Signed-off-by: Greg Thelen <gthelen@google.com> Acked-by: Michal Hocko <mhocko@suse.com> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Greg Thelen [Thu, 1 Oct 2015 22:37:05 +0000 (15:37 -0700)]
memcg: make mem_cgroup_read_stat() unsigned
mem_cgroup_read_stat() returns a page count by summing per cpu page
counters. The summing is racy wrt. updates, so a transient negative
sum is possible. Callers don't want negative values:
- mem_cgroup_wb_stats() doesn't want negative nr_dirty or nr_writeback.
This could confuse dirty throttling.
- oom reports and memory.stat shouldn't show confusing negative usage.
- tree_usage() already avoids negatives.
Avoid returning negative page counts from mem_cgroup_read_stat() and
convert it to unsigned.
[akpm@linux-foundation.org: fix old typo while we're in there] Signed-off-by: Greg Thelen <gthelen@google.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Acked-by: Michal Hocko <mhocko@suse.com> Cc: <stable@vger.kernel.org> [4.2+] Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Greg Thelen [Thu, 1 Oct 2015 22:37:02 +0000 (15:37 -0700)]
memcg: fix dirty page migration
The problem starts with a file backed dirty page which is charged to a
memcg. Then page migration is used to move oldpage to newpage.
Migration:
- copies the oldpage's data to newpage
- clears oldpage.PG_dirty
- sets newpage.PG_dirty
- uncharges oldpage from memcg
- charges newpage to memcg
Clearing oldpage.PG_dirty decrements the charged memcg's dirty page
count.
However, because newpage is not yet charged, setting newpage.PG_dirty
does not increment the memcg's dirty page count. After migration
completes newpage.PG_dirty is eventually cleared, often in
account_page_cleaned(). At this time newpage is charged to a memcg so
the memcg's dirty page count is decremented which causes underflow
because the count was not previously incremented by migration. This
underflow causes balance_dirty_pages() to see a very large unsigned
number of dirty memcg pages which leads to aggressive throttling of
buffered writes by processes in non root memcg.
This issue:
- can harm performance of non root memcg buffered writes.
- can report too small (even negative) values in
memory.stat[(total_)dirty] counters of all memcg, including the root.
To avoid polluting migrate.c with #ifdef CONFIG_MEMCG checks, introduce
page_memcg() and set_page_memcg() helpers.
Test:
0) setup and enter limited memcg
mkdir /sys/fs/cgroup/test
echo 1G > /sys/fs/cgroup/test/memory.limit_in_bytes
echo $$ > /sys/fs/cgroup/test/cgroup.procs
Notice that unpatched baseline performance (1) fell after
migration (3): 841 -> 114 MB/s. In the patched kernel, post
migration performance matches baseline.
Fixes: c4843a7593a9 ("memcg: add per cgroup dirty page accounting") Signed-off-by: Greg Thelen <gthelen@google.com> Reported-by: Dave Hansen <dave.hansen@intel.com> Acked-by: Michal Hocko <mhocko@suse.com> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Cc: <stable@vger.kernel.org> [4.2+] Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Ross Zwisler [Thu, 1 Oct 2015 22:36:59 +0000 (15:36 -0700)]
dax: fix NULL pointer in __dax_pmd_fault()
Commit 46c043ede471 ("mm: take i_mmap_lock in unmap_mapping_range() for
DAX") moved some code in __dax_pmd_fault() that was responsible for
zeroing newly allocated PMD pages. The new location didn't properly set
up 'kaddr', so when run this code resulted in a NULL pointer BUG.
Fix this by getting the correct 'kaddr' via bdev_direct_access().
Signed-off-by: Ross Zwisler <ross.zwisler@linux.intel.com> Reported-by: Dan Williams <dan.j.williams@intel.com> Reviewed-by: Dan Williams <dan.j.williams@intel.com> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Matthew Wilcox <willy@linux.intel.com> Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> Cc: Dave Chinner <david@fromorbit.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
I think I find a linux bug, I have the test cases is constructed. I
can stable recurring problems in fedora22(4.0.4) kernel version,
arch for x86_64. I construct transparent huge page, when the parent
and child process with MAP_SHARE, MAP_PRIVATE way to access the same
huge page area, it has the opportunity to lead to huge page copy on
write failure, and then it will munmap the child corresponding mmap
area, but then the child mmap area with VM_MAYSHARE attributes, child
process munmap this area can trigger VM_BUG_ON in set_vma_resv_flags
functions (vma - > vm_flags & VM_MAYSHARE).
There were a number of problems with the report (e.g. it's hugetlbfs that
triggers this, not transparent huge pages) but it was fundamentally
correct in that a VM_BUG_ON in set_vma_resv_flags() can be triggered that
looks like this
vma ffff8804651fd0d0 start 00007fc474e00000 end 00007fc475e00000
next ffff8804651fd018 prev ffff8804651fd188 mm ffff88046b1b1800
prot 8000000000000027 anon_vma (null) vm_ops ffffffff8182a7a0
pgoff 0 file ffff88106bdb9800 private_data (null)
flags: 0x84400fb(read|write|shared|mayread|maywrite|mayexec|mayshare|dontexpand|hugetlb)
------------
kernel BUG at mm/hugetlb.c:462!
SMP
Modules linked in: xt_pkttype xt_LOG xt_limit [..]
CPU: 38 PID: 26839 Comm: map Not tainted 4.0.4-default #1
Hardware name: Dell Inc. PowerEdge R810/0TT6JF, BIOS 2.7.4 04/26/2012
set_vma_resv_flags+0x2d/0x30
The VM_BUG_ON is correct because private and shared mappings have
different reservation accounting but the warning clearly shows that the
VMA is shared.
When a private COW fails to allocate a new page then only the process
that created the VMA gets the page -- all the children unmap the page.
If the children access that data in the future then they get killed.
The problem is that the same file is mapped shared and private. During
the COW, the allocation fails, the VMAs are traversed to unmap the other
private pages but a shared VMA is found and the bug is triggered. This
patch identifies such VMAs and skips them.
Kernels after v3.9 use kmalloc_size(INDEX_NODE + 1) to get the next
larger cache size than the size index INDEX_NODE mapping. In kernels
3.9 and earlier we used malloc_sizes[INDEX_L3 + 1].cs_size.
However, sometimes we can't get the right output we expected via
kmalloc_size(INDEX_NODE + 1), causing a BUG().
The mapping table in the latest kernel is like:
index = {0, 1, 2 , 3, 4, 5, 6, n}
size = {0, 96, 192, 8, 16, 32, 64, 2^n}
The mapping table before 3.10 is like this:
index = {0 , 1 , 2, 3, 4 , 5 , 6, n}
size = {32, 64, 96, 128, 192, 256, 512, 2^(n+3)}
The problem on my mips64 machine is as follows:
(1) When configured DEBUG_SLAB && DEBUG_PAGEALLOC && DEBUG_LOCK_ALLOC
&& DEBUG_SPINLOCK, the sizeof(struct kmem_cache_node) will be "150",
and the macro INDEX_NODE turns out to be "2": #define INDEX_NODE
kmalloc_index(sizeof(struct kmem_cache_node))
(2) Then the result of kmalloc_size(INDEX_NODE + 1) is 8.
(3) Then "if(size >= kmalloc_size(INDEX_NODE + 1)" will lead to "size
= PAGE_SIZE".
(4) Then "if ((size >= (PAGE_SIZE >> 3))" test will be satisfied and
"flags |= CFLGS_OFF_SLAB" will be covered.
(5) if (flags & CFLGS_OFF_SLAB)" test will be satisfied and will go to
"cachep->slabp_cache = kmalloc_slab(slab_size, 0u)", and the result
here may be NULL while kernel bootup.
(6) Finally,"BUG_ON(ZERO_OR_NULL_PTR(cachep->slabp_cache));" causes the
BUG info as the following shows (may be only mips64 has this problem):
This patch fixes the problem of kmalloc_size(INDEX_NODE + 1) and removes
the BUG by adding 'size >= 256' check to guarantee that all necessary
small sized slabs are initialized regardless sequence of slab size in
mapping table.
Fixes: e33660165c90 ("slab: Use common kmalloc_index/kmalloc_size...") Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com> Reported-by: Liuhailong <liu.hailong6@zte.com.cn> Acked-by: Christoph Lameter <cl@linux.com> Cc: Pekka Enberg <penberg@kernel.org> Cc: David Rientjes <rientjes@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Andre Przywara [Thu, 1 Oct 2015 22:36:51 +0000 (15:36 -0700)]
userfaultfd: remove kernel header include from uapi header
As include/uapi/linux/userfaultfd.h is a user visible header file, it
should not include kernel-exclusive header files.
So trying to build the userfaultfd test program from the selftests
directory fails, since it contains a reference to linux/compiler.h. As
it turns out, that header is not really needed there, so we can simply
remove it to fix that issue.
Signed-off-by: Andre Przywara <andre.przywara@arm.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Shuah Khan <shuahkh@osg.samsung.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Andrey Ryabinin [Thu, 1 Oct 2015 22:36:48 +0000 (15:36 -0700)]
arch/x86/include/asm/efi.h: fix build failure
With KMEMCHECK=y, KASAN=n:
arch/x86/platform/efi/efi.c:673:3: error: implicit declaration of function `memcpy' [-Werror=implicit-function-declaration]
arch/x86/platform/efi/efi_64.c:139:2: error: implicit declaration of function `memcpy' [-Werror=implicit-function-declaration]
arch/x86/include/asm/desc.h:121:2: error: implicit declaration of function `memcpy' [-Werror=implicit-function-declaration]
Dave Airlie [Fri, 2 Oct 2015 00:47:29 +0000 (10:47 +1000)]
Merge tag 'drm-intel-fixes-2015-10-01' of git://anongit.freedesktop.org/drm-intel into drm-fixes
a few i915 fixes for v4.3.
* tag 'drm-intel-fixes-2015-10-01' of git://anongit.freedesktop.org/drm-intel:
drm/i915: Call non-locking version of drm_kms_helper_poll_enable(), v2
drm: Add a non-locking version of drm_kms_helper_poll_enable(), v2
drm/i915: Consider HW CSB write pointer before resetting the sw read pointer
drm/i915/skl: Don't call intel_prepare_ddi when encoder list isn't yet initialized.
Dave Airlie [Fri, 2 Oct 2015 00:46:18 +0000 (10:46 +1000)]
Merge branch 'exynos-drm-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/daeinki/drm-exynos into drm-fixes
This pull request includes regression fixups, build warnings, and
trivial cleanups which mostly remove some codes not used anymore.
* 'exynos-drm-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/daeinki/drm-exynos:
drm/exynos: Staticize local function in exynos_drm_gem.c
drm/exynos: fimd: actually disable dp clock
drm/exynos: dp: remove suspend/resume functions
drm/exynos: remove unused mode_fixup() code
drm/exynos: remove decon_mode_fixup()
drm/exynos: remove fimd_mode_fixup()
drm/exynos: rotator: Clock control is unused if !PM
drm/exynos: fimc: Clock control is unused if !PM
drm/exynos: Suspend/resume is unused if !PM
drm/exynos: create a fake mmap offset with gem creation
drm/exynos: remove call to drm_gem_free_mmap_offset()
drm/exynos: Remove useless EXPORT_SYMBOL_GPLs
drm/exynos: cleanup line feed in exynos_drm_gem_get_ioctl
drm/exynos: cleanup function calling written twice
drm/exynos: staticize exynos_drm_gem_init()
drm/exynos: remove unnecessary NULL assignment
drm/exynos: fix missed calling of drm_prime_gem_destroy()
drm/exynos: fix layering violation of address
Linus Torvalds [Thu, 1 Oct 2015 20:43:25 +0000 (16:43 -0400)]
Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm
Pull KVM fixes from Paolo Bonzini:
"(Relatively) a lot of reverts, mostly.
Bugs have trickled in for a new feature in 4.2 (MTRR support in
guests) so I'm reverting it all; let's not make this -rc period busier
for KVM than it's been so far. This covers the four reverts from me.
The fifth patch is being reverted because Radim found a bug in the
implementation of stable scheduler clock, *but* also managed to
implement the feature entirely without hypervisor support. So instead
of fixing the hypervisor side we can remove it completely; 4.4 will
get the new implementation"
* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm:
Use WARN_ON_ONCE for missing X86_FEATURE_NRIPS
Update KVM homepage Url
Revert "KVM: SVM: use NPT page attributes"
Revert "KVM: svm: handle KVM_X86_QUIRK_CD_NW_CLEARED in svm_get_mt_mask"
Revert "KVM: SVM: Sync g_pat with guest-written PAT value"
Revert "KVM: x86: apply guest MTRR virtualization on host reserved pages"
Revert "KVM: x86: zero kvmclock_offset when vcpu0 initializes kvmclock system MSR"
Linus Torvalds [Thu, 1 Oct 2015 20:38:52 +0000 (16:38 -0400)]
Merge tag 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dledford/rdma
Pull rdma fixes from Doug Ledford:
- Fixes for mlx5 related issues
- Fixes for ipoib multicast handling
* tag 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dledford/rdma:
IB/ipoib: increase the max mcast backlog queue
IB/ipoib: Make sendonly multicast joins create the mcast group
IB/ipoib: Expire sendonly multicast joins
IB/mlx5: Remove pa_lkey usages
IB/mlx5: Remove support for IB_DEVICE_LOCAL_DMA_LKEY
IB/iser: Add module parameter for always register memory
xprtrdma: Replace global lkey with lkey local to PD
* pm-tools:
tools/power turbosat: update version number
tools/power turbostat: SKL: Adjust for TSC difference from base frequency
tools/power turbostat: KNL workaround for %Busy and Avg_MHz
tools/power turbostat: IVB Xeon: fix --debug regression
Steve Capper [Thu, 1 Oct 2015 12:06:07 +0000 (13:06 +0100)]
arm64: Fix THP protection change logic
6910fa1 ("arm64: enable PTE type bit in the mask for pte_modify") fixes
a problem whereby a large block of PROT_NONE mapped memory is
incorrectly mapped as block descriptors when mprotect is called.
Unfortunately, a subtle bug was introduced by this fix to the THP logic.
If one mmaps a large block of memory, then faults it such that it is
collapsed into THPs; resulting calls to mprotect on this area of memory
will lead to incorrect table descriptors being written instead of block
descriptors. This is because pmd_modify calls pte_modify which is now
allowed to modify the type of the page table entry.
This patch reverts commit 6910fa16dbe142f6a0fd0fd7c249f9883ff7fc8a, and
fixes the problem it was trying to address by adjusting PAGE_NONE to
represent a table entry. Thus no change in pte type is required when
moving from PROT_NONE to a different protection.
Fixes: 6910fa16dbe1 ("arm64: enable PTE type bit in the mask for pte_modify") Cc: <stable@vger.kernel.org> # 4.0+ Cc: Feng Kan <fkan@apm.com> Reported-by: Ganapatrao Kulkarni <Ganapatrao.Kulkarni@caviumnetworks.com> Tested-by: Ganapatrao Kulkarni <gkulkarni@caviumnetworks.com> Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Steve Capper <steve.capper@linaro.org> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Ralf Baechle [Thu, 1 Oct 2015 13:45:44 +0000 (15:45 +0200)]
MIPS: BPF: Do all exports of symbols with FEXPORT().
FEXPORT also marks the symbol as code using .type symbol, @function.
Without objdump -d will output only a hexdump for code following the
affected symbols.
Dirk Müller [Thu, 1 Oct 2015 11:43:42 +0000 (13:43 +0200)]
Use WARN_ON_ONCE for missing X86_FEATURE_NRIPS
The cpu feature flags are not ever going to change, so warning
everytime can cause a lot of kernel log spam
(in our case more than 10GB/hour).
The warning seems to only occur when nested virtualization is
enabled, so it's probably triggered by a KVM bug. This is a
sensible and safe change anyway, and the KVM bug fix might not
be suitable for stable releases anyway.
Cc: stable@vger.kernel.org Signed-off-by: Dirk Mueller <dmueller@suse.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Linus Torvalds [Thu, 1 Oct 2015 11:57:27 +0000 (07:57 -0400)]
Merge tag 'upstream-4.3-rc4' of git://git.infradead.org/linux-ubifs
Pull UBI/UBIFS fixes from Richard Weinberger:
"This contains three bug fixes for both UBI and UBIFS"
* tag 'upstream-4.3-rc4' of git://git.infradead.org/linux-ubifs:
UBI: return ENOSPC if no enough space available
UBI: Validate data_size
UBIFS: Kill unneeded locking in ubifs_init_security
Linus Torvalds [Thu, 1 Oct 2015 11:50:08 +0000 (07:50 -0400)]
Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security
Pull key signing fixes from James Morris:
"Keyrings and modsign fixes from David Howells"
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security:
MODSIGN: Change from CMS to PKCS#7 signing if the openssl is too old
X.509: Don't strip leading 00's from key ID when constructing key description
KEYS: Remove unnecessary header #inclusions from extract-cert.c
KEYS: Fix race between key destruction and finding a keyring by name
Paolo Bonzini [Thu, 1 Oct 2015 11:20:22 +0000 (13:20 +0200)]
Revert "KVM: SVM: use NPT page attributes"
This reverts commit 3c2e7f7de3240216042b61073803b61b9b3cfb22.
Initializing the mapping from MTRR to PAT values was reported to
fail nondeterministically, and it also caused extremely slow boot
(due to caching getting disabled---bug 103321) with assigned devices.
Reported-by: Markus Trippelsdorf <markus@trippelsdorf.de> Reported-by: Sebastian Schuette <dracon@ewetel.net> Cc: stable@vger.kernel.org # 4.2+ Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
arm64/efi: Fix boot crash by not padding between EFI_MEMORY_RUNTIME regions
The new Properties Table feature introduced in UEFIv2.5 may
split memory regions that cover PE/COFF memory images into
separate code and data regions. Since these regions only differ
in the type (runtime code vs runtime data) and the permission
bits, but not in the memory type attributes (UC/WC/WT/WB), the
spec does not require them to be aligned to 64 KB.
Since the relative offset of PE/COFF .text and .data segments
cannot be changed on the fly, this means that we can no longer
pad out those regions to be mappable using 64 KB pages.
Unfortunately, there is no annotation in the UEFI memory map
that identifies data regions that were split off from a code
region, so we must apply this logic to all adjacent runtime
regions whose attributes only differ in the permission bits.
So instead of rounding each memory region to 64 KB alignment at
both ends, only round down regions that are not directly
preceded by another runtime region with the same type
attributes. Since the UEFI spec does not mandate that the memory
map be sorted, this means we also need to sort it first.
Note that this change will result in all EFI_MEMORY_RUNTIME
regions whose start addresses are not aligned to the OS page
size to be mapped with executable permissions (i.e., on kernels
compiled with 64 KB pages). However, since these mappings are
only active during the time that UEFI Runtime Services are being
invoked, the window for abuse is rather small.
Tested-by: Mark Salter <msalter@redhat.com> Tested-by: Mark Rutland <mark.rutland@arm.com> [UEFI 2.4 only] Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: Matt Fleming <matt.fleming@intel.com> Reviewed-by: Mark Salter <msalter@redhat.com> Reviewed-by: Mark Rutland <mark.rutland@arm.com> Cc: <stable@vger.kernel.org> # v4.0+ Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Leif Lindholm <leif.lindholm@linaro.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Will Deacon <will.deacon@arm.com> Cc: linux-kernel@vger.kernel.org Link: http://lkml.kernel.org/r/1443218539-7610-3-git-send-email-matt@codeblueprint.co.uk Signed-off-by: Ingo Molnar <mingo@kernel.org>
Matt Fleming [Fri, 25 Sep 2015 22:02:18 +0000 (23:02 +0100)]
x86/efi: Fix boot crash by mapping EFI memmap entries bottom-up at runtime, instead of top-down
Beginning with UEFI v2.5 EFI_PROPERTIES_TABLE was introduced
that signals that the firmware PE/COFF loader supports splitting
code and data sections of PE/COFF images into separate EFI
memory map entries. This allows the kernel to map those regions
with strict memory protections, e.g. EFI_MEMORY_RO for code,
EFI_MEMORY_XP for data, etc.
Unfortunately, an unwritten requirement of this new feature is
that the regions need to be mapped with the same offsets
relative to each other as observed in the EFI memory map. If
this is not done crashes like this may occur,
Here 0xfffffffefe6086dd refers to an address the firmware
expects to be mapped but which the OS never claimed was mapped.
The issue is that included in these regions are relative
addresses to other regions which were emitted by the firmware
toolchain before the "splitting" of sections occurred at
runtime.
Needless to say, we don't satisfy this unwritten requirement on
x86_64 and instead map the EFI memory map entries in reverse
order. The above crash is almost certainly triggerable with any
kernel newer than v3.13 because that's when we rewrote the EFI
runtime region mapping code, in commit d2f7cbe7b26a ("x86/efi:
Runtime services virtual mapping"). For kernel versions before
v3.13 things may work by pure luck depending on the
fragmentation of the kernel virtual address space at the time we
map the EFI regions.
Instead of mapping the EFI memory map entries in reverse order,
where entry N has a higher virtual address than entry N+1, map
them in the same order as they appear in the EFI memory map to
preserve this relative offset between regions.
This patch has been kept as small as possible with the intention
that it should be applied aggressively to stable and
distribution kernels. It is very much a bugfix rather than
support for a new feature, since when EFI_PROPERTIES_TABLE is
enabled we must map things as outlined above to even boot - we
have no way of asking the firmware not to split the code/data
regions.
In fact, this patch doesn't even make use of the more strict
memory protections available in UEFI v2.5. That will come later.
Suggested-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Reported-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: Matt Fleming <matt.fleming@intel.com> Cc: <stable@vger.kernel.org> Cc: Borislav Petkov <bp@suse.de> Cc: Chun-Yi <jlee@suse.com> Cc: Dave Young <dyoung@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: James Bottomley <JBottomley@Odin.com> Cc: Lee, Chun-Yi <jlee@suse.com> Cc: Leif Lindholm <leif.lindholm@linaro.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Matthew Garrett <mjg59@srcf.ucam.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Jones <pjones@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-kernel@vger.kernel.org Link: http://lkml.kernel.org/r/1443218539-7610-2-git-send-email-matt@codeblueprint.co.uk Signed-off-by: Ingo Molnar <mingo@kernel.org>
Ben Hutchings [Sat, 26 Sep 2015 11:23:56 +0000 (12:23 +0100)]
genirq: Fix race in register_irq_proc()
Per-IRQ directories in procfs are created only when a handler is first
added to the irqdesc, not when the irqdesc is created. In the case of
a shared IRQ, multiple tasks can race to create a directory. This
race condition seems to have been present forever, but is easier to
hit with async probing.
blk-mq: factor out a helper to iterate all tags for a request_queue
And replace the blk_mq_tag_busy_iter with it - the driver use has been
replaced with a new helper a while ago, and internal to the block we
only need the new version.
Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@fb.com>
blk_mq_complete_request may be a no-op if the request has already
been completed by others means (e.g. a timeout or cancellation), but
currently drivers have to set rq->errors before calling
blk_mq_complete_request, which might leave us with the wrong error value.
Add an error parameter to blk_mq_complete_request so that we can
defer setting rq->errors until we known we won the race to complete the
request.
Alban Bedel [Fri, 4 Sep 2015 12:29:16 +0000 (14:29 +0200)]
MIPS: Fix the build on jz4740 after removing the custom gpio.h
Somehow the wrong version of the patch to remove the use of custom
gpio.h on mips has been merged. This patch add the missing fixes for a
build error on jz4740 because linux/gpio.h doesn't provide any machine
specfics definitions anymore.
Signed-off-by: Alban Bedel <albeu@free.fr> Cc: Paul Burton <paul.burton@imgtec.com> Cc: Lars-Peter Clausen <lars@metafoo.de> Cc: Brian Norris <computersforpeace@gmail.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Linus Walleij <linus.walleij@linaro.org> Cc: linux-mips@linux-mips.org Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/11089/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Robert Jarzmik [Wed, 30 Sep 2015 17:42:15 +0000 (19:42 +0200)]
dmaengine: pxa_dma: fix residue corner case
A very tiny temporal window exists in the residue calculation where :
- upon entering residue calculation, the transfer is ongoing
- when reading the current transfer pointer, it just changed to
the "finisher/linker" descriptor
In this case, the residue returned is the whole transfer length instead
of 0. Fix it.
This appears almost in one extreme case, where the driver is used
by older clients which inquire for residue in interrupt context, such
as the smsc91x ethernet driver, in a tight loop :
interrupt_handler()
dmaengine_submit()
do {
dmaengine_tx_status()
} while (residue > 0 || status != DMA_ERROR)
Signed-off-by: Robert Jarzmik <robert.jarzmik@free.fr> Signed-off-by: Vinod Koul <vinod.koul@intel.com>
Robert Jarzmik [Wed, 30 Sep 2015 17:42:14 +0000 (19:42 +0200)]
dmaengine: pxa_dma: fix the no-requestor case
A very small number of devices don't use the flow control offered by
requestor lines. In these specific cases, the pxa dma driver should be
aware of that and not try to use a requestor line.
Signed-off-by: Robert Jarzmik <robert.jarzmik@free.fr> Signed-off-by: Vinod Koul <vinod.koul@intel.com>
When putting back a descriptor to the free descs list, some fields are
not set to 0, it can cause bugs if someone uses it without having this
in mind.
Descriptor are not put back one by one so it is easier to clean
descriptors when we request them.
The addressing mode we were using was not only incrementing the address at
each microblock, but also at each data boundary, which was severely slowing
the transfer, without any benefit since we were not using the data stride.
Switch to the micro block increment only in order to get back to an
acceptable performance level.
Thomas Gleixner [Wed, 30 Sep 2015 08:38:22 +0000 (08:38 +0000)]
x86/process: Add proper bound checks in 64bit get_wchan()
Dmitry Vyukov reported the following using trinity and the memory
error detector AddressSanitizer
(https://code.google.com/p/address-sanitizer/wiki/AddressSanitizerForKernel).
[ 124.575597] ERROR: AddressSanitizer: heap-buffer-overflow on
address ffff88002e280000
[ 124.576801] ffff88002e280000 is located 131938492886538 bytes to
the left of 28857600-byte region [ffffffff81282e0a, ffffffff82e0830a)
[ 124.578633] Accessed by thread T10915:
[ 124.579295] inlined in describe_heap_address
./arch/x86/mm/asan/report.c:164
[ 124.579295] #0 ffffffff810dd277 in asan_report_error
./arch/x86/mm/asan/report.c:278
[ 124.580137] #1 ffffffff810dc6a0 in asan_check_region
./arch/x86/mm/asan/asan.c:37
[ 124.581050] #2 ffffffff810dd423 in __tsan_read8 ??:0
[ 124.581893] #3 ffffffff8107c093 in get_wchan
./arch/x86/kernel/process_64.c:444
The address checks in the 64bit implementation of get_wchan() are
wrong in several ways:
- The lower bound of the stack is not the start of the stack
page. It's the start of the stack page plus sizeof (struct
thread_info)
The 2 * sizeof(unsigned long) is required because the stack pointer
points at the frame pointer. The layout on the stack is: ... IP FP
... IP FP. So we need to make sure that both IP and FP are in the
bounds.
Fix the bound checks and get rid of the mix of numeric constants, u64
and unsigned long. Making all unsigned long allows us to use the same
function for 32bit as well.
Use READ_ONCE() when accessing the stack. This does not prevent a
concurrent wakeup of the task and the stack changing, but at least it
avoids TOCTOU.
Also check task state at the end of the loop. Again that does not
prevent concurrent changes, but it avoids walking for nothing.