On old ARM chips, unaligned accesses to memory are not trapped and
fixed.  On module load, symbols are relocated, and the relocation of
__bug_table symbols is done on a u32 basis. Yet the section is not
aligned to a multiple of 4 address, but to a multiple of 2.

This triggers an Oops on pxa architecture, where address 0xbf0021ea
is the first relocation in the __bug_table section :
  apply_relocate(): pxa3xx_nand: section 13 reloc 0 sym ''
  Unable to handle kernel paging request at virtual address bf0021ea
  pgd = e1cd0000
  [bf0021ea] *pgd=c1cce851, *pte=c1cde04f, *ppte=c1cde01f
  Internal error: Oops: 23 [#1] ARM
  Modules linked in:
  CPU: 0 PID: 606 Comm: insmod Not tainted 4.2.0-rc8-next-20150828-cm-x300+ #887
  Hardware name: CM-X300 module
  task: e1c68700 ti: e1c3e000 task.ti: e1c3e000
  PC is at apply_relocate+0x2f4/0x3d4
  LR is at 0xbf0021ea
  pc : [<c000e7c8>]    lr : [<bf0021ea>]    psr: 80000013
  sp : e1c3fe30  ip : 60000013  fp : e49e8c60
  r10: e49e8fa8  r9 : 00000000  r8 : e49e7c58
  r7 : e49e8c38  r6 : e49e8a58  r5 : e49e8920  r4 : e49e8918
  r3 : bf0021ea  r2 : bf007034  r1 : 00000000  r0 : bf000000
  Flags: Nzcv  IRQs on  FIQs on  Mode SVC_32  ISA ARM  Segment none
  Control: 0000397f  Table: c1cd0018  DAC: 00000051
  Process insmod (pid: 606, stack limit = 0xe1c3e198)
  [<c000e7c8>] (apply_relocate) from [<c005ce5c>] (load_module+0x1248/0x1f5c)
  [<c005ce5c>] (load_module) from [<c005dc54>] (SyS_init_module+0xe4/0x170)
  [<c005dc54>] (SyS_init_module) from [<c000a420>] (ret_fast_syscall+0x0/0x38)

Fix this by ensuring entries in __bug_table are all aligned to at least
of multiple of 4. This transforms a module section  __bug_table as :
-   [12] __bug_table       PROGBITS        00000000 002232 000018 00   A  0   0  1
+   [12] __bug_table       PROGBITS        00000000 002232 000018 00   A  0   0  4
Signed-off-by: Robert Jarzmik <robert.jarzmik@free.fr>
Reviewed-by: Dave Martin <Dave.Martin@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

While working on the 32-bit ARM port of UEFI, I noticed a strange
corruption in the kernel log. The following snprintf() statement
(in drivers/firmware/efi/efi.c:efi_md_typeattr_format())

	snprintf(pos, size, "|%3s|%2s|%2s|%2s|%3s|%2s|%2s|%2s|%2s]",

was producing the following output in the log:

	|    |   |   |   |    |WB|WT|WC|UC]
	|    |   |   |   |    |WB|WT|WC|UC]
	|    |   |   |   |    |WB|WT|WC|UC]
	|RUN|   |   |   |    |WB|WT|WC|UC]*
	|RUN|   |   |   |    |WB|WT|WC|UC]*
	|    |   |   |   |    |WB|WT|WC|UC]
	|RUN|   |   |   |    |WB|WT|WC|UC]*
	|    |   |   |   |    |WB|WT|WC|UC]
	|RUN|   |   |   |    |   |   |   |UC]
	|RUN|   |   |   |    |   |   |   |UC]

As it turns out, this is caused by incorrect code being emitted for
the string() function in lib/vsprintf.c. The following code

	if (!(spec.flags & LEFT)) {
		while (len < spec.field_width--) {
			if (buf < end)
				*buf = ' ';
			++buf;
		}
	}
	for (i = 0; i < len; ++i) {
		if (buf < end)
			*buf = *s;
		++buf; ++s;
	}
	while (len < spec.field_width--) {
		if (buf < end)
			*buf = ' ';
		++buf;
	}

when called with len == 0, triggers an issue in the GCC SRA optimization
pass (Scalar Replacement of Aggregates), which handles promotion of signed
struct members incorrectly. This is a known but as yet unresolved issue.
(https://gcc.gnu.org/bugzilla/show_bug.cgi?id=65932). In this particular
case, it is causing the second while loop to be executed erroneously a
single time, causing the additional space characters to be printed.

So disable the optimization by passing -fno-ipa-sra.

Cc: <stable@vger.kernel.org>
Acked-by: Nicolas Pitre <nico@linaro.org>
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

U-Boot is often used to boot the kernel on ARM boards, but uImage
is not built by "make all", so we are often inclined to do
"make all uImage" to generate DTBs, modules and uImage in a single
command, but we should notice a pitfall behind it.  In fact,
"make all uImage" could generate an invalid uImage if it is run with
the parallel option (-j).

You can reproduce this problem with the following procedure:

[1] First, build "all" and "uImage" separately.
    You will get a valid uImage

  $ git clean -f -x -d
  $ export CROSS_COMPILE=<your-tools-prefix>
  $ make -s -j8 ARCH=arm multi_v7_defconfig
  $ make -s -j8 ARCH=arm all
  $ make -j8 ARCH=arm UIMAGE_LOADADDR=0x80208000 uImage
    CHK     include/config/kernel.release
    CHK     include/generated/uapi/linux/version.h
    CHK     include/generated/utsrelease.h
  make[1]: `include/generated/mach-types.h' is up to date.
    CHK     include/generated/timeconst.h
    CHK     include/generated/bounds.h
    CHK     include/generated/asm-offsets.h
    CALL    scripts/checksyscalls.sh
    CHK     include/generated/compile.h
    Kernel: arch/arm/boot/Image is ready
    Kernel: arch/arm/boot/zImage is ready
    UIMAGE  arch/arm/boot/uImage
  Image Name:   Linux-4.2.0-rc5-00156-gdd2384a7-d
  Created:      Sat Aug  8 23:21:35 2015
  Image Type:   ARM Linux Kernel Image (uncompressed)
  Data Size:    6138648 Bytes = 5994.77 kB = 5.85 MB
  Load Address: 80208000
  Entry Point:  80208000
    Image arch/arm/boot/uImage is ready
  $ ls -l arch/arm/boot/*Image
  -rwxrwxr-x 1 masahiro masahiro 13766656 Aug  8 23:20 arch/arm/boot/Image
  -rw-rw-r-- 1 masahiro masahiro  6138712 Aug  8 23:21 arch/arm/boot/uImage
  -rwxrwxr-x 1 masahiro masahiro  6138648 Aug  8 23:20 arch/arm/boot/zImage

[2] Update some source file(s)

  $ touch init/main.c

[3] Then, re-build "all" and "uImage" simultaneously.
    You will get an invalid uImage at random.

  $ make -j8 ARCH=arm UIMAGE_LOADADDR=0x80208000 all uImage
    CHK     include/config/kernel.release
    CHK     include/generated/uapi/linux/version.h
    CHK     include/generated/utsrelease.h
  make[1]: `include/generated/mach-types.h' is up to date.
    CHK     include/generated/timeconst.h
    CHK     include/generated/bounds.h
    CHK     include/generated/asm-offsets.h
    CALL    scripts/checksyscalls.sh
    CC      init/main.o
    CHK     include/generated/compile.h
    LD      init/built-in.o
    LINK    vmlinux
    LD      vmlinux.o
    MODPOST vmlinux.o
    GEN     .version
    CHK     include/generated/compile.h
    UPD     include/generated/compile.h
    CC      init/version.o
    LD      init/built-in.o
    KSYM    .tmp_kallsyms1.o
    KSYM    .tmp_kallsyms2.o
    LD      vmlinux
    SORTEX  vmlinux
    SYSMAP  System.map
    OBJCOPY arch/arm/boot/Image
    Building modules, stage 2.
    Kernel: arch/arm/boot/Image is ready
    GZIP    arch/arm/boot/compressed/piggy.gzip
    AS      arch/arm/boot/compressed/piggy.gzip.o
    Kernel: arch/arm/boot/Image is ready
    LD      arch/arm/boot/compressed/vmlinux
    GZIP    arch/arm/boot/compressed/piggy.gzip
    OBJCOPY arch/arm/boot/zImage
    Kernel: arch/arm/boot/zImage is ready
    UIMAGE  arch/arm/boot/uImage
  Image Name:   Linux-4.2.0-rc5-00156-gdd2384a7-d
  Created:      Sat Aug  8 23:23:14 2015
  Image Type:   ARM Linux Kernel Image (uncompressed)
  Data Size:    26472 Bytes = 25.85 kB = 0.03 MB
  Load Address: 80208000
  Entry Point:  80208000
    Image arch/arm/boot/uImage is ready
    MODPOST 192 modules
    AS      arch/arm/boot/compressed/piggy.gzip.o
    LD      arch/arm/boot/compressed/vmlinux
    OBJCOPY arch/arm/boot/zImage
    Kernel: arch/arm/boot/zImage is ready
  $ ls -l arch/arm/boot/*Image
  -rwxrwxr-x 1 masahiro masahiro 13766656 Aug  8 23:23 arch/arm/boot/Image
  -rw-rw-r-- 1 masahiro masahiro    26536 Aug  8 23:23 arch/arm/boot/uImage
  -rwxrwxr-x 1 masahiro masahiro  6138648 Aug  8 23:23 arch/arm/boot/zImage

Please notice the uImage is extremely small when this issue is
encountered.  Besides, "Kernel: arch/arm/boot/zImage is ready" is
displayed twice, before and after the uImage log.

The root cause of this is the race condition between zImage and
uImage.  Actually, uImage depends on zImage, but the dependency
between the two is only described in arch/arm/boot/Makefile.
Because arch/arm/boot/Makefile is not included from the top-level
Makefile, it cannot know the dependency between zImage and uImage.

Consequently, when we run make with the parallel option, Kbuild
updates vmlinux first, and then two different threads descends into
the arch/arm/boot/Makefile almost at the same time, one for updating
zImage and the other for uImage.  While one thread is re-generating
zImage, the other also tries to update zImage before creating uImage
on top of that.  zImage is overwritten by the slower thread and then
uImage is created based on the half-written zImage.

This is the reason why "Kernel: arch/arm/boot/zImage is ready" is
displayed twice, and a broken uImage is created.

The same problem could happen on bootpImage.

This commit adds dependencies among Image, zImage, uImage, and
bootpImage to arch/arm/Makefile, which is included from the
top-level Makefile.
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

The mmap semaphore should not be taken when page faults are disabled.
Since pagefault_disable() no longer disables preemption, we now need
to use faulthandler_disabled() in place of in_atomic().
Signed-off-by: Nicolas Pitre <nico@linaro.org>
Tested-by: Mark Salter <msalter@redhat.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

Since 906c5557 ("timekeeping: Copy the shadow-timekeeper over the
real timekeeper last") it has become possible on ARM to:

- Obtain a CLOCK_MONOTONIC_COARSE or CLOCK_REALTIME_COARSE timestamp
  via syscall.
- Subsequently obtain a timestamp for the same clock ID via VDSO which
  predates the first timestamp (by one jiffy).

This is because ARM's update_vsyscall is deriving the coarse time
using the __current_kernel_time interface, when it should really be
using the timekeeper object provided to it by the timekeeping core.
It happened to work before only because __current_kernel_time would
access the same timekeeper object which had been passed to
update_vsyscall.  This is no longer the case.

Cc: stable@vger.kernel.org
Fixes: 906c5557 ("timekeeping: Copy the shadow-timekeeper over the real timekeeper last")
Signed-off-by: Nathan Lynch <nathan_lynch@mentor.com>
Acked-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

ret_fast_syscall runs when user space makes a syscall. However it
needs to be marked as such so the ELF information is correct. Before
it was:

   101: 8000f300     0 NOTYPE  LOCAL  DEFAULT    2 ret_fast_syscall

But with this change it correctly shows as:

   101: 8000f300    96 FUNC    LOCAL  DEFAULT    2 ret_fast_syscall

I see this function when using perf to unwind call stacks from kernel
space to user space. Without this change I would need to add some
special case logic when using the vmlinux ELF information.
Signed-off-by: Drew Richardson <drew.richardson@arm.com>
Acked-by: Nicolas Pitre <nico@linaro.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

Since the commit "b2c3e38a ARM: redo TTBR setup code for LPAE",
the setup code had been reworked. As a result the secondary CPUs
failed to come online in Big Endian.

As explained by Russell, the new code expected the value in r4/r5 to
be the least significant 32bits in r4 and the most significant 32bits
in r5. However, in the secondary code, we load this using ldrd, which
on BE reverses that.

This patch swap r4/r5 after the ldrd. It is done using the xor
instructions in order to not use a temporary register.
Signed-off-by: Gregory CLEMENT <gregory.clement@free-electrons.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

The Sourcery CodeBench Lite 2014.05 toolchain (gcc 4.8.3, binutils
2.24.51) has a GCC which implements -fuse-ld, and it doesn't include
the gold linker, but it lacks an ld.bfd executable in its
installation.  This means that passing -fuse-ld=bfd fails with:

      VDSO    arch/arm/vdso/vdso.so.raw
    collect2: fatal error: cannot find 'ld'

Arguably this is a deficiency in the toolchain, but I suspect it's
commonly used enough that it's worth accommodating: just use

cc-ldoption (to cause a link attempt) instead of cc-option to test
whether we can use -fuse-ld.  So -fuse-ld=bfd won't be used with this
toolchain, but the build will rightly succeed, just as it does for
toolchains which don't implement -fuse-ld (and don't use gold as the
default linker).

Note: this will change the failure mode for a corner case I was trying
to handle in d2b30cd4, where the toolchain defaults to the gold
linker and the BFD linker is not found in PATH, from:

      VDSO    arch/arm/vdso/vdso.so.raw
    collect2: fatal error: cannot find 'ld'

i.e. the BFD linker is not found, to:

      OBJCOPY arch/arm/vdso/vdso.so
    BFD: arch/arm/vdso/vdso.so: Not enough room for program headers, try
    linking with -N

that is, we fail to prevent gold from being used as the linker, and it
produces an object that objcopy can't digest.
Reported-by: Baruch Siach <baruch@tkos.co.il>
Tested-by: Baruch Siach <baruch@tkos.co.il>
Tested-by: Raphaël Poggi <poggi.raph@gmail.com>
Fixes: d2b30cd4 ("ARM: 8384/1: VDSO: force use of BFD linker")
Cc: stable@vger.kernel.org
Signed-off-by: Nathan Lynch <nathan_lynch@mentor.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

Fengguang Wu reports that building ARM with !MMU results in the
following build error:

   arch/arm/kernel/built-in.o: In function `__soft_restart':
>> :(.text+0x1624): undefined reference to `arch_virt_to_idmap'

Fix this by adding an appropriate IS_ENABLED(CONFIG_MMU) into the
__virt_to_idmap() inline function.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

We must invalidate the L1 cache before enabling coherency, otherwise
secondary CPUs can inject invalid cache lines into the coherent CPU
cluster, which could then be migrated to other CPUs.  This fixes a
recent regression with SoCFPGA randomly failing to boot.

Fixes: 02b4e275 ("ARM: v7 setup function should invalidate L1 cache")
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

nr_bitmaps member of mapping structure stores the number of already
allocated bitmaps and it is interpreted as loop iterator (it starts from
0 not from 1), so a comparison against number of possible bitmap
extensions should include this fact. This patch fixes this by changing
the extension failure condition. This issue has been introduced by
commit 4d852ef8 ("arm: dma-mapping: Add
support to extend DMA IOMMU mappings").
Reported-by: Hyungwon Hwang <human.hwang@samsung.com>
Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Reviewed-by: Hyungwon Hwang <human.hwang@samsung.com>
Cc: stable@vger.kernel.org  # v3.15+
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

It's possible, albeit unlikely, that using the of_node here will
reference freed memory. Call of_node_put() after printing the
name to be safe.
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

This patch is to get correct physical address of the reset function for
PAE systems, which use aliased physical memory for booting.

See the "ARM: mm: Introduce virt_to_idmap() with an arch hook" for details.
Signed-off-by: Vitaly Andrianov <vitalya@ti.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

This reverts commit dec4f799.

Jörg Otte reports a NULL pointder dereference due to this commit, as
'crtc_state' very much can be NULL:

        crtc_state = state->base.state ?
                intel_atomic_get_crtc_state(state->base.state, intel_crtc) : NULL;

So the change to test 'crtc_state->base.active' cannot possibly be
correct as-is.

There may be some other minimal fix (like just checking crtc_state for
NULL), but I'm just reverting it now for the rc2 release, and people
like Daniel Vetter who actually know this code will figure out what the
right solution is in the longer term.
Reported-and-bisected-by: Jörg Otte <jrg.otte@gmail.com>
Cc: Ander Conselvan de Oliveira <ander.conselvan.de.oliveira@intel.com>
Cc: Jani Nikula <jani.nikula@linux.intel.com>
Cc: Daniel Vetter <daniel.vetter@intel.com>
CC: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Pull VFS fixes from Al Viro:
 "Fixes for this cycle regression in overlayfs and a couple of
  long-standing (== all the way back to 2.6.12, at least) bugs"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  freeing unlinked file indefinitely delayed
  fix a braino in ovl_d_select_inode()
  9p: don't leave a half-initialized inode sitting around

Pull MIPS fixes from Ralf Baechle:
 "A fair number of 4.2 fixes also because Markos opened the flood gates.

   - Patch up the math used calculate the location for the page bitmap.

   - The FDC (Not what you think, FDC stands for Fast Debug Channel) IRQ
     around was causing issues on non-Malta platforms, so move the code
     to a Malta specific location.

   - A spelling fix replicated through several files.

   - Fix to the emulation of an R2 instruction for R6 cores.

   - Fix the JR emulation for R6.

   - Further patching of mindless 64 bit issues.

   - Ensure the kernel won't crash on CPUs with L2 caches with >= 8
     ways.

   - Use compat_sys_getsockopt for O32 ABI on 64 bit kernels.

   - Fix cache flushing for multithreaded cores.

   - A build fix"

* 'upstream' of git://git.linux-mips.org/pub/scm/ralf/upstream-linus:
  MIPS: O32: Use compat_sys_getsockopt.
  MIPS: c-r4k: Extend way_string array
  MIPS: Pistachio: Support CDMM & Fast Debug Channel
  MIPS: Malta: Make GIC FDC IRQ workaround Malta specific
  MIPS: c-r4k: Fix cache flushing for MT cores
  Revert "MIPS: Kconfig: Disable SMP/CPS for 64-bit"
  MIPS: cps-vec: Use macros for various arithmetics and memory operations
  MIPS: kernel: cps-vec: Replace KSEG0 with CKSEG0
  MIPS: kernel: cps-vec: Use ta0-ta3 pseudo-registers for 64-bit
  MIPS: kernel: cps-vec: Replace mips32r2 ISA level with mips64r2
  MIPS: kernel: cps-vec: Replace 'la' macro with PTR_LA
  MIPS: kernel: smp-cps: Fix 64-bit compatibility errors due to pointer casting
  MIPS: Fix erroneous JR emulation for MIPS R6
  MIPS: Fix branch emulation for BLTC and BGEC instructions
  MIPS: kernel: traps: Fix broken indentation
  MIPS: bootmem: Don't use memory holes for page bitmap
  MIPS: O32: Do not handle require 32 bytes from the stack to be readable.
  MIPS, CPUFREQ: Fix spelling of Institute.
  MIPS: Lemote 2F: Fix build caused by recent mass rename.

Pull x86 fixes from Thomas Gleixner:

 - the high latency PIT detection fix, which slipped through the cracks
   for rc1

 - a regression fix for the early printk mechanism

 - the x86 part to plug irq/vector related hotplug races

 - move the allocation of the espfix pages on cpu hotplug to non atomic
   context.  The current code triggers a might_sleep() warning.

 - a series of KASAN fixes addressing boot crashes and usability

 - a trivial typo fix for Kconfig help text

* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/kconfig: Fix typo in the CONFIG_CMDLINE_BOOL help text
  x86/irq: Retrieve irq data after locking irq_desc
  x86/irq: Use proper locking in check_irq_vectors_for_cpu_disable()
  x86/irq: Plug irq vector hotplug race
  x86/earlyprintk: Allow early_printk() to use console style parameters like '115200n8'
  x86/espfix: Init espfix on the boot CPU side
  x86/espfix: Add 'cpu' parameter to init_espfix_ap()
  x86/kasan: Move KASAN_SHADOW_OFFSET to the arch Kconfig
  x86/kasan: Add message about KASAN being initialized
  x86/kasan: Fix boot crash on AMD processors
  x86/kasan: Flush TLBs after switching CR3
  x86/kasan: Fix KASAN shadow region page tables
  x86/init: Clear 'init_level4_pgt' earlier
  x86/tsc: Let high latency PIT fail fast in quick_pit_calibrate()

Pull timer fixes from Thomas Gleixner:
 "This update from the timer departement contains:

   - A series of patches which address a shortcoming in the tick
     broadcast code.

     If the broadcast device is not available or an hrtimer emulated
     broadcast device, some of the original assumptions lead to boot
     failures.  I rather plugged all of the corner cases instead of only
     addressing the issue reported, so the change got a little larger.

     Has been extensivly tested on x86 and arm.

   - Get rid of the last holdouts using do_posix_clock_monotonic_gettime()

   - A regression fix for the imx clocksource driver

   - An update to the new state callbacks mechanism for clockevents.
     This is required to simplify the conversion, which will take place
     in 4.3"

* 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  tick/broadcast: Prevent NULL pointer dereference
  time: Get rid of do_posix_clock_monotonic_gettime
  cris: Replace do_posix_clock_monotonic_gettime()
  tick/broadcast: Unbreak CONFIG_GENERIC_CLOCKEVENTS=n build
  tick/broadcast: Handle spurious interrupts gracefully
  tick/broadcast: Check for hrtimer broadcast active early
  tick/broadcast: Return busy when IPI is pending
  tick/broadcast: Return busy if periodic mode and hrtimer broadcast
  tick/broadcast: Move the check for periodic mode inside state handling
  tick/broadcast: Prevent deep idle if no broadcast device available
  tick/broadcast: Make idle check independent from mode and config
  tick/broadcast: Sanity check the shutdown of the local clock_event
  tick/broadcast: Prevent hrtimer recursion
  clockevents: Allow set-state callbacks to be optional
  clocksource/imx: Define clocksource for mx27

Pull irq fix from Thomas Gleixner:
 "A single fix for a cpu hotplug race vs. interrupt descriptors:

  Prevent irq setup/teardown across the cpu starting/dying parts of cpu
  hotplug so that the starting/dying cpu has a stable view of the
  descriptor space.  This has been an issue for all architectures in the
  cpu dying phase, where interrupts are migrated away from the dying
  cpu.  In the starting phase its mostly a x86 issue vs the vector space
  update"

* 'irq-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  hotplug: Prevent alloc/free of irq descriptors during cpu up/down

	Normally opening a file, unlinking it and then closing will have
the inode freed upon close() (provided that it's not otherwise busy and
has no remaining links, of course).  However, there's one case where that
does *not* happen.  Namely, if you open it by fhandle with cold dcache,
then unlink() and close().

	In normal case you get d_delete() in unlink(2) notice that dentry
is busy and unhash it; on the final dput() it will be forcibly evicted from
dcache, triggering iput() and inode removal.  In this case, though, we end
up with *two* dentries - disconnected (created by open-by-fhandle) and
regular one (used by unlink()).  The latter will have its reference to inode
dropped just fine, but the former will not - it's considered hashed (it
is on the ->s_anon list), so it will stay around until the memory pressure
will finally do it in.  As the result, we have the final iput() delayed
indefinitely.  It's trivial to reproduce -

void flush_dcache(void)
{
        system("mount -o remount,rw /");
}

static char buf[20 * 1024 * 1024];

main()
{
        int fd;
        union {
                struct file_handle f;
                char buf[MAX_HANDLE_SZ];
        } x;
        int m;

        x.f.handle_bytes = sizeof(x);
        chdir("/root");
        mkdir("foo", 0700);
        fd = open("foo/bar", O_CREAT | O_RDWR, 0600);
        close(fd);
        name_to_handle_at(AT_FDCWD, "foo/bar", &x.f, &m, 0);
        flush_dcache();
        fd = open_by_handle_at(AT_FDCWD, &x.f, O_RDWR);
        unlink("foo/bar");
        write(fd, buf, sizeof(buf));
        system("df .");			/* 20Mb eaten */
        close(fd);
        system("df .");			/* should've freed those 20Mb */
        flush_dcache();
        system("df .");			/* should be the same as #2 */
}

will spit out something like
Filesystem     1K-blocks   Used Available Use% Mounted on
/dev/root         322023 303843      1131 100% /
Filesystem     1K-blocks   Used Available Use% Mounted on
/dev/root         322023 303843      1131 100% /
Filesystem     1K-blocks   Used Available Use% Mounted on
/dev/root         322023 283282     21692  93% /
- inode gets freed only when dentry is finally evicted (here we trigger
than by remount; normally it would've happened in response to memory
pressure hell knows when).

Cc: stable@vger.kernel.org # v2.6.38+; earlier ones need s/kill_it/unhash_it/
Acked-by: J. Bruce Fields <bfields@fieldses.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

when opening a directory we want the overlayfs inode, not one from
the topmost layer.
Reported-By: Andrey Jr. Melnikov <temnota.am@gmail.com>
Tested-By: Andrey Jr. Melnikov <temnota.am@gmail.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

Cc: stable@vger.kernel.org # all branches
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

Pull libnvdimm fixes from Dan Williams:
 "1) Fixes for a handful of smatch reports (Thanks Dan C.!) and minor
     bug fixes (patches 1-6)

  2) Correctness fixes to the BLK-mode nvdimm driver (patches 7-10).

     Granted these are slightly large for a -rc update.  They have been
     out for review in one form or another since the end of May and were
     deferred from the merge window while we settled on the "PMEM API"
     for the PMEM-mode nvdimm driver (ie memremap_pmem, memcpy_to_pmem,
     and wmb_pmem).

     Now that those apis are merged we implement them in the BLK driver
     to guarantee that mmio aperture moves stay ordered with respect to
     incoming read/write requests, and that writes are flushed through
     those mmio-windows and platform-buffers to be persistent on media.

  These pass the sub-system unit tests with the updates to
  tools/testing/nvdimm, and have received a successful build-report from
  the kbuild robot (468 configs).

  With acks from Rafael for the touches to drivers/acpi/"

* 'libnvdimm-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/djbw/nvdimm:
  nfit: add support for NVDIMM "latch" flag
  nfit: update block I/O path to use PMEM API
  tools/testing/nvdimm: add mock acpi_nfit_flush_address entries to nfit_test
  tools/testing/nvdimm: fix return code for unimplemented commands
  tools/testing/nvdimm: mock ioremap_wt
  pmem: add maintainer for include/linux/pmem.h
  nfit: fix smatch "use after null check" report
  nvdimm: Fix return value of nvdimm_bus_init() if class_create() fails
  libnvdimm: smatch cleanups in __nd_ioctl
  sparse: fix misplaced __pmem definition

Pull i2c fixes from Wolfram Sang:
 "Mostly slight adjusments for new drivers, but also one core fix for
  which finally the dependencies are now available as well"

* 'i2c/for-current' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux:
  i2c: Mark instantiated device nodes with OF_POPULATE
  i2c: jz4780: Fix return value if probe fails
  i2c: xgene-slimpro: Fix missing mbox_free_channel call in probe error path
  i2c: I2C_MT65XX should depend on HAS_DMA

Pull input fixes from Dmitry Torokhov:
 "A fix (revert) for a recent regression in Synaptics driver and a fix
  for Elan i2c touchpad driver"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input:
  Revert "Input: synaptics - allocate 3 slots to keep stability in image sensors"
  Input: elan_i2c - change the hover event from MT to ST

Pull clk fixes from Stephen Boyd:
 "A small set of fixes for problems found by smatch in new drivers that
  we added this rc and a handful of driver fixes that came in during the
  merge window"

* tag 'clk-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/clk/linux:
  drivers: clk: st: Incorrect register offset used for lock_status
  clk: mediatek: mt8173: Fix enabling of critical clocks
  drivers: clk: st: Fix mux bit-setting for Cortex A9 clocks
  drivers: clk: st: Add CLK_GET_RATE_NOCACHE flag to clocks
  drivers: clk: st: Fix flexgen lock init
  drivers: clk: st: Fix FSYN channel values
  drivers: clk: st: Remove unused code
  clk: qcom: Use parent rate when set rate to pixel RCG clock
  clk: at91: do not leak resources
  clk: stm32: Fix out-by-one error path in the index lookup
  clk: iproc: fix bit manipulation arithmetic
  clk: iproc: fix memory leak from clock name

Pull drm fixes from Dave Airlie:
 "A bunch of fixes for radeon, intel, omap and one amdkfd fix.

  Radeon fixes are all over, but it does fix some cursor corruption
  across suspend/resume.  i915 should fix the second warn you were
  seeing, so let us know if not.  omap is a bunch of small fixes"

* 'drm-fixes' of git://people.freedesktop.org/~airlied/linux: (28 commits)
  drm/radeon: disable vce init on cayman (v2)
  drm/amdgpu: fix timeout calculation
  drm/radeon: check if BO_VA is set before adding it to the invalidation list
  drm/radeon: allways add the VM clear duplicate
  Revert "Revert "drm/radeon: dont switch vt on suspend""
  drm/radeon: Fold radeon_set_cursor() into radeon_show_cursor()
  drm/radeon: unpin cursor BOs on suspend and pin them again on resume (v2)
  drm/radeon: Clean up reference counting and pinning of the cursor BOs
  drm/amdkfd: validate pdd where it acquired first
  Revert "drm/i915: Allocate context objects from stolen"
  drm/i915: Declare the swizzling unknown for L-shaped configurations
  drm/radeon: fix underflow in r600_cp_dispatch_texture()
  drm/radeon: default to 2048 MB GART size on SI+
  drm/radeon: fix HDP flushing
  drm/radeon: use RCU query for GEM_BUSY syscall
  drm/amdgpu: Handle irqs only based on irq ring, not irq status regs.
  drm/radeon: Handle irqs only based on irq ring, not irq status regs.
  drm/i915: Use crtc_state->active in primary check_plane func
  drm/i915: Check crtc->active in intel_crtc_disable_planes
  drm/i915: Restore all GGTT VMAs on resume
  ...

Pull selinux fixes from James Morris.

* 'for-linus2' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security:
  selinux: fix mprotect PROT_EXEC regression caused by mm change
  selinux: don't waste ebitmap space when importing NetLabel categories

Pull btrfs fixes from Chris Mason:
 "This is an assortment of fixes.  Most of the commits are from Filipe
  (fsync, the inode allocation cache and a few others).  Mark kicked in
  a series fixing corners in the extent sharing ioctls, and everyone
  else fixed up on assorted other problems"

* 'for-linus-4.2' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs:
  Btrfs: fix wrong check for btrfs_force_chunk_alloc()
  Btrfs: fix warning of bytes_may_use
  Btrfs: fix hang when failing to submit bio of directIO
  Btrfs: fix a comment in inode.c:evict_inode_truncate_pages()
  Btrfs: fix memory corruption on failure to submit bio for direct IO
  btrfs: don't update mtime/ctime on deduped inodes
  btrfs: allow dedupe of same inode
  btrfs: fix deadlock with extent-same and readpage
  btrfs: pass unaligned length to btrfs_cmp_data()
  Btrfs: fix fsync after truncate when no_holes feature is enabled
  Btrfs: fix fsync xattr loss in the fast fsync path
  Btrfs: fix fsync data loss after append write
  Btrfs: fix crash on close_ctree() if cleaner starts new transaction
  Btrfs: fix race between caching kthread and returning inode to inode cache
  Btrfs: use kmem_cache_free when freeing entry in inode cache
  Btrfs: fix race between balance and unused block group deletion
  btrfs: add error handling for scrub_workers_get()
  btrfs: cleanup noused initialization of dev in btrfs_end_bio()
  btrfs: qgroup: allow user to clear the limitation on qgroup

Pull ARM SoC fixes from Kevin Hilman:
 "A fairly random colletion of fixes based on -rc1 for OMAP, sunxi and
  prima2 as well as a few arm64-specific DT fixes.

  This series also includes a late to support a new Allwinner (sunxi)
  SoC, but since it's rather simple and isolated to the
  platform-specific code, it's included it for this -rc"

* tag 'armsoc-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc:
  arm64: dts: add device tree for ARM SMM-A53x2 on LogicTile Express 20MG
  arm: dts: vexpress: add missing CCI PMU device node to TC2
  arm: dts: vexpress: describe all PMUs in TC2 dts
  GICv3: Add ITS entry to THUNDER dts
  arm64: dts: Add poweroff button device node for APM X-Gene platform
  ARM: dts: am4372.dtsi: disable rfbi
  ARM: dts: am57xx-beagle-x15: Provide supply for usb2_phy2
  ARM: dts: am4372: Add emif node
  Revert "ARM: dts: am335x-boneblack: disable RTC-only sleep"
  ARM: sunxi: Enable simplefb in the defconfig
  ARM: Remove deprecated symbol from defconfig files
  ARM: sunxi: Add Machine support for A33
  ARM: sunxi: Introduce Allwinner H3 support
  Documentation: sunxi: Update Allwinner SoC documentation
  ARM: prima2: move to use REGMAP APIs for rtciobrg
  ARM: dts: atlas7: add pinctrl and gpio descriptions
  ARM: OMAP2+: Remove unnessary return statement from the void function, omap2_show_dma_caps
  memory: omap-gpmc: Fix parsing of devices

Dan reported that the recent changes to the broadcast code introduced
a potential NULL dereference.

Add the proper check.

Fixes: e0454311 "tick/broadcast: Sanity check the shutdown of the local clock_event"
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

Pull parisc fixes from Helge Deller:
 "We have one important patch from Dave Anglin and myself which fixes
  PTE/TLB race conditions which caused random segmentation faults on our
  debian buildd servers, and one patch from Alex Ivanov which speeds up
  the graphical text console on the STI framebuffer driver"

* 'parisc-4.2-1' of git://git.kernel.org/pub/scm/linux/kernel/git/deller/parisc-linux:
  parisc: Fix some PTE/TLB race conditions and optimize __flush_tlb_range based on timing results
  stifb: Implement hardware accelerated copyarea

commit 66fc1303 ("mm: shmem_zero_setup
skip security check and lockdep conflict with XFS") caused a regression
for SELinux by disabling any SELinux checking of mprotect PROT_EXEC on
shared anonymous mappings.  However, even before that regression, the
checking on such mprotect PROT_EXEC calls was inconsistent with the
checking on a mmap PROT_EXEC call for a shared anonymous mapping.  On a
mmap, the security hook is passed a NULL file and knows it is dealing
with an anonymous mapping and therefore applies an execmem check and no
file checks.  On a mprotect, the security hook is passed a vma with a
non-NULL vm_file (as this was set from the internally-created shmem
file during mmap) and therefore applies the file-based execute check
and no execmem check.  Since the aforementioned commit now marks the
shmem zero inode with the S_PRIVATE flag, the file checks are disabled
and we have no checking at all on mprotect PROT_EXEC.  Add a test to
the mprotect hook logic for such private inodes, and apply an execmem
check in that case.  This makes the mmap and mprotect checking
consistent for shared anonymous mappings, as well as for /dev/zero and
ashmem.

Cc: <stable@vger.kernel.org> # 4.1.x
Signed-off-by: Stephen Smalley <sds@tycho.nsa.gov>
Signed-off-by: Paul Moore <pmoore@redhat.com>

Pull arm64 fixes and clean-up from Catalin Marinas:
 - ACPI fix when checking the validity of the GICC MADT subtable
 - handle debug exceptions in the el*_inv exception entries
 - remove pointless register assignment in two compat syscall wrappers
 - unnecessary include path
 - defconfig update

* tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux:
  arm64: entry32: remove pointless register assignment
  arm64: entry: handle debug exceptions in el*_inv
  arm64: Keep the ARM64 Kconfig selects sorted
  ACPI / ARM64 : use the new BAD_MADT_GICC_ENTRY macro
  ACPI / ARM64: add BAD_MADT_GICC_ENTRY() macro
  arm64: defconfig: Add Ceva ahci to the defconfig
  arm64: remove another unnecessary libfdt include path

The increased use of pdtlb/pitlb instructions seemed to increase the
frequency of random segmentation faults building packages. Further, we
had a number of cases where TLB inserts would repeatedly fail and all
forward progress would stop. The Haskell ghc package caused a lot of
trouble in this area. The final indication of a race in pte handling was
this syslog entry on sibaris (C8000):

 swap_free: Unused swap offset entry 00000004
 BUG: Bad page map in process mysqld  pte:00000100 pmd:019bbec5
 addr:00000000ec464000 vm_flags:00100073 anon_vma:0000000221023828 mapping: (null) index:ec464
 CPU: 1 PID: 9176 Comm: mysqld Not tainted 4.0.0-2-parisc64-smp #1 Debian 4.0.5-1
 Backtrace:
  [<0000000040173eb0>] show_stack+0x20/0x38
  [<0000000040444424>] dump_stack+0x9c/0x110
  [<00000000402a0d38>] print_bad_pte+0x1a8/0x278
  [<00000000402a28b8>] unmap_single_vma+0x3d8/0x770
  [<00000000402a4090>] zap_page_range+0xf0/0x198
  [<00000000402ba2a4>] SyS_madvise+0x404/0x8c0

Note that the pte value is 0 except for the accessed bit 0x100. This bit
shouldn't be set without the present bit.

It should be noted that the madvise system call is probably a trigger for many
of the random segmentation faults.

In looking at the kernel code, I found the following problems:

1) The pte_clear define didn't take TLB lock when clearing a pte.
2) We didn't test pte present bit inside lock in exception support.
3) The pte and tlb locks needed to merged in order to ensure consistency
between page table and TLB. This also has the effect of serializing TLB
broadcasts on SMP systems.

The attached change implements the above and a few other tweaks to try
to improve performance. Based on the timing code, TLB purges are very
slow (e.g., ~ 209 cycles per page on rp3440). Thus, I think it
beneficial to test the split_tlb variable to avoid duplicate purges.
Probably, all PA 2.0 machines have combined TLBs.

I dropped using __flush_tlb_range in flush_tlb_mm as I realized all
applications and most threads have a stack size that is too large to
make this useful. I added some comments to this effect.

Since implementing 1 through 3, I haven't had any random segmentation
faults on mx3210 (rp3440) in about one week of building code and running
as a Debian buildd.
Signed-off-by: John David Anglin <dave.anglin@bell.net>
Cc: stable@vger.kernel.org # v3.18+
Signed-off-by: Helge Deller <deller@gmx.de>

This patch adds hardware assisted scrolling. The code is based upon the
following investigation: https://parisc.wiki.kernel.org/index.php/NGLE#Blitter

A simple 'time ls -la /usr/bin' test shows 1.6x speed increase over soft
copy and 2.3x increase over FBINFO_READS_FAST (prefer soft copy over
screen redraw) on Artist framebuffer.
Signed-off-by: Alex Ivanov <lausgans@gmail.com>
Signed-off-by: Helge Deller <deller@gmx.de>

Pull powerpc fixes from Michael Ellerman:
 - opal-prd mmap fix from Vaidy
 - set kernel taint for MCEs from Daniel
 - alignment exception description from Anton
 - ppc4xx_hsta_msi build fix from Daniel
 - opal-elog interrupt fix from Alistair
 - core_idle_state race fix from Shreyas
 - hv-24x7 lockdep fix from Sukadev
 - multiple cxl fixes from Daniel, Ian, Mikey & Maninder
 - update MAINTAINERS to point at shared tree

* tag 'powerpc-4.2-2' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux:
  cxl: Check if afu is not null in cxl_slbia
  powerpc: Update MAINTAINERS to point at shared tree
  powerpc/perf/24x7: Fix lockdep warning
  cxl: Fix off by one error allowing subsequent mmap page to be accessed
  cxl: Fail mmap if requested mapping is larger than assigned problem state area
  cxl: Fix refcounting in kernel API
  powerpc/powernv: Fix race in updating core_idle_state
  powerpc/powernv: Fix opal-elog interrupt handler
  powerpc/ppc4xx_hsta_msi: Include ppc-pci.h to fix reference to hose_list
  powerpc: Add plain English description for alignment exception oopses
  cxl: Test the correct mmio space before unmapping
  powerpc: Set the correct kernel taint on machine check errors
  cxl/vphb.c: Use phb pointer after NULL check
  powerpc/powernv: Fix vma page prot flags in opal-prd driver

Add support in the NFIT BLK I/O path for the "latch" flag
defined in the "Get Block NVDIMM Flags" _DSM function:

http://pmem.io/documents/NVDIMM_DSM_Interface_Example.pdf

This flag requires the driver to read back the command register after it
is written in the block I/O path.  This ensures that the hardware has
fully processed the new command and moved the aperture appropriately.
Signed-off-by: Ross Zwisler <ross.zwisler@linux.intel.com>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>