Checkin:

b3b42ac2 x86-64, modify_ldt: Ban 16-bit segments on 64-bit kernels

disabled 16-bit segments on 64-bit kernels due to an information
leak.  However, it does seem that people are genuinely using Wine to
run old 16-bit Windows programs on Linux.

A proper fix for this ("espfix64") is coming in the upcoming merge
window, but as a temporary fix, create a sysctl to allow the
administrator to re-enable support for 16-bit segments.

It adds a "/proc/sys/abi/ldt16" sysctl that defaults to zero (off). If
you hit this issue and care about your old Windows program more than
you care about a kernel stack address information leak, you can do

   echo 1 > /proc/sys/abi/ldt16

as root (add it to your startup scripts), and you should be ok.

The sysctl table is only added if you have COMPAT support enabled on
x86-64, but I assume anybody who runs old windows binaries very much
does that ;)
Signed-off-by: NH. Peter Anvin <hpa@linux.intel.com>
Link: http://lkml.kernel.org/r/CA%2B55aFw9BPoD10U1LfHbOMpHWZkvJTkMcfCs9s3urPr1YyWBxw@mail.gmail.com
Cc: <stable@vger.kernel.org>

The invalidation is required in order to maintain proper semantics
under CoW conditions. In scenarios where a process clones several
threads, a thread operating on a core whose DTLB entry for a
particular hugepage has not been invalidated, will be reading from
the hugepage that belongs to the forked child process, even after
hugetlb_cow().

The thread will not see the updated page as long as the stale DTLB
entry remains cached, the thread attempts to write into the page,
the child process exits, or the thread gets migrated to a different
processor.
Signed-off-by: NAnthony Iliopoulos <anthony.iliopoulos@huawei.com>
Link: http://lkml.kernel.org/r/20140514092948.GA17391@server-36.huawei.corpSuggested-by: NShay Goikhman <shay.goikhman@huawei.com>
Acked-by: NDave Hansen <dave.hansen@intel.com>
Signed-off-by: NH. Peter Anvin <hpa@linux.intel.com>
Cc: <stable@vger.kernel.org> # v2.6.16+ (!)

virt_to_pfn has been defined in arch/arm/include/asm/memory.h by commit
e26a9e00 "ARM: Better virt_to_page() handling" and Xen has come to rely
on it.  Introduce virt_to_pfn on arm64 too.
Signed-off-by: NStefano Stabellini <stefano.stabellini@eu.citrix.com>
Acked-by: NCatalin Marinas <catalin.marinas@arm.com>

One can logically expect that when the user has specified "nordrand",
the user doesn't want any use of the CPU random number generator,
neither RDRAND nor RDSEED, so disable both.
Reported-by: NStephan Mueller <smueller@chronox.de>
Cc: Theodore Ts'o <tytso@mit.edu>
Link: http://lkml.kernel.org/r/21542339.0lFnPSyGRS@myon.chronox.deSigned-off-by: NH. Peter Anvin <hpa@linux.intel.com>

The IPU register space is 128MB, not 2GB.

Fixes: abed9a6b 'ARM i.MX53: Add IPU support'
Signed-off-by: NSascha Hauer <s.hauer@pengutronix.de>
Acked-by: NShawn Guo <shawn.guo@freescale.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: NOlof Johansson <olof@lixom.net>

With tk->wall_to_monotonic.tv_nsec being a 32-bit value on 32-bit
systems, (tk->wall_to_monotonic.tv_nsec << tk->shift) in update_vsyscall()
may lose upper bits or, worse, add them since compiler will do this:
	(u64)(tk->wall_to_monotonic.tv_nsec << tk->shift)
instead of
	((u64)tk->wall_to_monotonic.tv_nsec << tk->shift)

So if, for example, tv_nsec is 0x800000 and shift is 8 we will end up
with 0xffffffff80000000 instead of 0x80000000. And then we are stuck in
the subsequent 'while' loop.

We need an explicit cast.
Signed-off-by: NBoris Ostrovsky <boris.ostrovsky@oracle.com>
Link: http://lkml.kernel.org/r/1399648287-15178-1-git-send-email-boris.ostrovsky@oracle.comAcked-by: NKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: <stable@vger.kernel.org> # v3.14
Signed-off-by: NH. Peter Anvin <hpa@zytor.com>

The spuriously added semicolon didn't have any effect because the
macro isn't currently in use.

c0a639adSigned-off-by: NAndres Freund <andres@anarazel.de>
Link: http://lkml.kernel.org/r/1399598957-7011-3-git-send-email-andres@anarazel.de
Cc: Borislav Petkov <bp@suse.de>
Signed-off-by: NH. Peter Anvin <hpa@zytor.com>

Due to a typo the msr accessor function introduced in
22085a66 didn't have any lasting
effects because they accidentally wrote the old value back.

After c0a639ad this at the very least
this causes cpuid limits not to be lifted on some cpus leading to
missing capabilities for those.
Signed-off-by: NAndres Freund <andres@anarazel.de>
Link: http://lkml.kernel.org/r/1399598957-7011-2-git-send-email-andres@anarazel.de
Cc: Borislav Petkov <bp@suse.de>
Signed-off-by: NH. Peter Anvin <hpa@zytor.com>

HPET on current Baytrail platform has accuracy problem to be
used as reliable clocksource/clockevent, so add a early quirk to
disable it.
Signed-off-by: NFeng Tang <feng.tang@intel.com>
Cc: Clemens Ladisch <clemens@ladisch.de>
Cc: John Stultz <john.stultz@linaro.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: http://lkml.kernel.org/r/1398327498-13163-2-git-send-email-feng.tang@intel.comSigned-off-by: NIngo Molnar <mingo@kernel.org>

HPET on some platform has accuracy problem. Making
"boot_hpet_disable" extern so that we can runtime disable
the HPET timer by using quirk to check the platform.
Signed-off-by: NFeng Tang <feng.tang@intel.com>
Cc: Clemens Ladisch <clemens@ladisch.de>
Cc: John Stultz <john.stultz@linaro.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: http://lkml.kernel.org/r/1398327498-13163-1-git-send-email-feng.tang@intel.comSigned-off-by: NIngo Molnar <mingo@kernel.org>

If you are using a 64-bit kernel with 32-bit userland, then
scripts/gcc-x86_64-has-stack-protector.sh invokes 32-bit gcc
with -mcmodel=kernel, which produces:

<stdin>:1:0: error: code model 'kernel' not supported in the 32 bit mode

and trips the "broken compiler" test at arch/x86/Makefile:120.

There are several places a fix is possible, but the following seems
cleanest.  (But it's minimal; it would also be possible to factor
out a bunch of stuff from the two branches of the if.)
Signed-off-by: NGeorge Spelvin <linux@horizon.com>
Link: http://lkml.kernel.org/r/20140507210552.7581.qmail@ns.horizon.com
Cc: <stable@vger.kernel.org> # v3.14
Signed-off-by: NH. Peter Anvin <hpa@linux.intel.com>

Certec BPC600 needs reboot=pci to actually reboot.
Signed-off-by: NChristian Gmeiner <christian.gmeiner@gmail.com>
Cc: Matthew Garrett <mjg59@srcf.ucam.org>
Cc: Li Aubrey <aubrey.li@linux.intel.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Dave Jones <davej@redhat.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: http://lkml.kernel.org/r/1399446114-2147-1-git-send-email-christian.gmeiner@gmail.comSigned-off-by: NIngo Molnar <mingo@kernel.org>

As requested by Linus add explicit __visible to the asmlinkage users.
This marks all functions visible to assembler.

Tree sweep for arch/x86/*
Signed-off-by: NAndi Kleen <ak@linux.intel.com>
Link: http://lkml.kernel.org/r/1398984278-29319-3-git-send-email-andi@firstfloor.orgSigned-off-by: NH. Peter Anvin <hpa@linux.intel.com>

arch/x86/crypto/sha1_avx2_x86_64_asm.S introduced _end as a local
symbol, which broke the build under certain circumstances.  Although
the wisdom of _end as a local symbol can definitely be questioned, the
build should not break for that reason.

Thus, filter the output of nm to only get global symbols of
appropriate type.
Reported-by: NAndy Lutomirski <luto@amacapital.net>
Cc: Chandramouli Narayanan <mouli@linux.intel.com>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: NH. Peter Anvin <hpa@linux.intel.com>
Link: http://lkml.kernel.org/n/tip-uxm3j3w3odglcwhafwq5tjqu@git.kernel.org

Build console support only when CONFIG_TTY is selected.
This restores ISS as the default platform for allnoconfig builds.
Signed-off-by: NMax Filippov <jcmvbkbc@gmail.com>
Signed-off-by: NChris Zankel <chris@zankel.net>

Commit 54397d85
 ("ARM: kirkwood: Relocate PCIe device tree nodes")

moved the pcie-controller nodes for the Kirkwood SoCs to the mbus
bus node. For some reason, two boards were not properly converted
and have their pci-controller nodes still in the ocp bus node.

As the corresponding SoC pcie-controller does not exist anymore,
it is likely that pcie is broken on those boards since above commit.
Fix it by moving the pcie related nodes to the correct location.
Signed-off-by: NSebastian Hesselbarth <sebastian.hesselbarth@gmail.com>
Fixes: 54397d85 ("ARM: kirkwood: Relocate PCIe device tree nodes")
Cc: <stable@vger.kernel.org> # v3.12+
Acked-by: NAndrew Lunn <andrew@lunn.ch>
Link: https://lkml.kernel.org/r/1398862602-29595-2-git-send-email-sebastian.hesselbarth@gmail.comSigned-off-by: NJason Cooper <jason@lakedaemon.net>

pte_ERROR() is not used anywhere, delete it.

For pgd_ERROR() and pmd_ERROR(), output something similar to x86, giving the address
of the pgd/pmd as well as it's value.

Also provide the caller, since these macros are invoked from pgd_clear_bad() and
pmd_clear_bad() which provides little context as to what high level operation was
occuring when the BAD state was detected.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Instead of returning false we should at least check the most basic
things, otherwise page table corruptions will be very difficult to
debug.

PMD and PTE tables are of size PAGE_SIZE, so none of the sub-PAGE_SIZE
bits should be set.

We also complement this with a check that the physical address the
pud/pmd points to is valid memory.

PowerPC was used as a guide while implementating this.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Signed-off-by: NDavid S. Miller <davem@davemloft.net>

In commit b2d43834 ("sparc64: Make
PAGE_OFFSET variable."), the MAX_PHYS_ADDRESS_BITS value was increased
(to 47).

This constant reference to '41UL' was missed.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Make get_user_insn() able to cope with huge PMDs.

Next, make do_fault_siginfo() more robust when get_user_insn() can't
actually fetch the instruction.  In particular, use the MMU announced
fault address when that happens, instead of calling
compute_effective_address() and computing garbage.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

If we have a 32-bit task we must chop off the top 32-bits of the
64-bit value just as the cpu would.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Signed-off-by: NDavid S. Miller <davem@davemloft.net>

When _PAGE_SPECIAL and _PAGE_PMD_HUGE were added to the mask, the
comment was not updated.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The large PMD path needs to check _PAGE_VALID not _PAGE_PRESENT, to
decide if it needs to bail and return 0.

pmd_large() should therefore just check _PAGE_PMD_HUGE.

Calls to gup_huge_pmd() are guarded with a check of pmd_large(), so we
just need to add a valid bit check.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

On sparc64 "present" and "valid" are seperate PTE bits, this allows us to
naturally distinguish between the user explicitly asking for PROT_NONE
with mprotect() and other situations.

However we weren't handling this properly in the huge PMD paths.

First of all, the page table walker in the TSB miss path only checks
for _PAGE_PMD_HUGE.  So the generic pmdp_invalidate() would clear
_PAGE_PRESENT but the TLB miss paths would still load it into the TLB
as a valid huge PMD.

Fix this by clearing the valid bit in pmdp_invalidate(), and also
checking the valid bit in USER_PGTABLE_CHECK_PMD_HUGE using "brgez"
since _PAGE_VALID is bit 63 in both the sun4u and sun4v pte layouts.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This code was mistakenly using the exec bit from the PMD in all
cases, even when the PMD isn't a huge PMD.

If it's not a huge PMD, test the exec bit in the individual ptes down
in tlb_batch_pmd_scan().
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Bring this code in line with the perf based generic NMI watchdog
in kernel/watchdog.c (which we should convert over to at some
point).

In particular, don't do anything super fancy when the watchdog
triggers, and specifically don't do a do_exit() which only makes
things worse.

Either panic(), or WARN().  The latter of which will do all of
the actions such as give us a stack backtrace.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Since the default DMA ops for arm64 are non-coherent, mark the X-Gene
controller explicitly as dma-coherent to avoid additional cache
maintenance.
Signed-off-by: NCatalin Marinas <catalin.marinas@arm.com>
Cc: Loc Ho <lho@apm.com>

Recently, the default DMA ops have been changed to non-coherent for
alignment with 32-bit ARM platforms (and DT files). This patch adds bus
notifiers to be able to set the coherent DMA ops (with no cache
maintenance) for devices explicitly marked as coherent via the
"dma-coherent" DT property.
Signed-off-by: NCatalin Marinas <catalin.marinas@arm.com>

Currently arm64 dma_ops is by default made coherent which makes it
opposite in default policy from arm.

Make default dma_ops to be noncoherent (same as arm), as currently there
aren't any dma-capable drivers which assumes coherent ops
Signed-off-by: NRitesh Harjani <ritesh.harjani@gmail.com>
Acked-by: NWill Deacon <will.deacon@arm.com>
Signed-off-by: NCatalin Marinas <catalin.marinas@arm.com>

Commit d57c33c5 (add generic fixmap.h) added (among other
similar things) set_fixmap_io to deal with early ioremap of devices.

More recently, commit bf4b558e (arm64: add early_ioremap support)
converted the arm64 earlyprintk to use set_fixmap_io. A side effect of
this conversion is that my virtual machines have stopped booting when
I pass "earlyprintk=uart8250-8bit,0x3f8" to the guest kernel.

Turns out that the new earlyprintk code doesn't care at all about
sub-page offsets, and just assumes that the earlyprintk device will
be page-aligned. Obviously, that doesn't play well with the above example.

Further investigation shows that set_fixmap_io uses __set_fixmap instead
of __set_fixmap_offset. A fix is to introduce a set_fixmap_offset_io that
uses the latter, and to remove the superflous call to fix_to_virt
(which only returns the value that set_fixmap_io has already given us).

With this applied, my VMs are back in business. Tested on a Cortex-A57
platform with kvmtool as platform emulation.

Cc: Will Deacon <will.deacon@arm.com>
Acked-by: NMark Salter <msalter@redhat.com>
Acked-by: NArnd Bergmann <arnd@arndb.de>
Signed-off-by: NMarc Zyngier <marc.zyngier@arm.com>
Signed-off-by: NCatalin Marinas <catalin.marinas@arm.com>

Fix for the arm64 kern_addr_valid() function to recognize
virtual addresses in the kernel logical memory map.  The
function fails as written because it does not check whether
the addresses in that region are mapped at the pmd level to
2MB or 512MB pages, continues the page table walk to the
pte level, and issues a garbage value to pfn_valid().

Tested on 4K-page and 64K-page kernels.
Signed-off-by: NDave Anderson <anderson@redhat.com>
Signed-off-by: NCatalin Marinas <catalin.marinas@arm.com>

earlyprintk=efi,keep will cause kernel hangs while freeing initmem like
below:

  VFS: Mounted root (ext4 filesystem) readonly on device 254:2.
  devtmpfs: mounted
  Freeing unused kernel memory: 880K (ffffffff817d4000 - ffffffff818b0000)

It is caused by efi earlyprintk use __init function which will be freed
later.  Such as early_efi_write is marked as __init, also it will use
early_ioremap which is init function as well.

To fix this issue, I added early initcall early_efi_map_fb which maps
the whole efi fb for later use. OTOH, adding a wrapper function
early_efi_map which calls early_ioremap before ioremap is available.

With this patch applied efi boot ok with earlyprintk=efi,keep console=efi
Signed-off-by: NDave Young <dyoung@redhat.com>
Signed-off-by: NMatt Fleming <matt.fleming@intel.com>

One more place where we must not be able
to be preempted or to be interrupted in RT.

Always actually disable interrupts during
synchronization cycle.
Signed-off-by: NKirill Tkhai <tkhai@yandex.ru>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Only the second argument, 'op', is signed.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Since the support of the GMAC has been merged, we're using it as the ethernet
controller on the A20 devices.

However, sunxi_defconfig wasn't selecting it hence breaking the NFS boot.
Signed-off-by: NMaxime Ripard <maxime.ripard@free-electrons.com>

Signed-off-by: NHelge Deller <deller@gmx.de>

There are only a couple of architectures that override _STK_LIM_MAX to
a non-infinity value. This changes the stack allocation semantics in
subtle ways. For example, GNU make changes its stack allocation to the
hard maximum defined by _STK_LIM_MAX. As a results, threads executed
by processes running under make are allocated a stack size of
_STK_LIM_MAX rather than a sensible default value. This causes various
thread stress tests to fail when they can't muster more than about 50
threads.

The attached change implements the default behavior used by the
majority of architectures.
Signed-off-by: NJohn David Anglin <dave.anglin@bell.net>
Reviewed-by: NCarlos O'Donell <carlos@systemhalted.org>
Cc: stable@vger.kernel.org # 3.14
Signed-off-by: NHelge Deller <deller@gmx.de>

Commit 93ea02bb ("arch: Clean up asm/barrier.h implementations")
wired generic barrier.h for hexagon, but failed to delete the existing
file.

Cc: Richard Kuo <rkuo@codeaurora.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: NVineet Gupta <vgupta@synopsys.com>
Compile-tested-by: NGuenter Roeck <linux@roeck-us.net>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>