The 'move_paghes()' system call was introduced long long ago with the
same permission checks as for sending a signal (except using
CAP_SYS_NICE instead of CAP_SYS_KILL for the overriding capability).

That turns out to not be a great choice - while the system call really
only moves physical page allocations around (and you need other
capabilities to do a lot of it), you can check the return value to map
out some the virtual address choices and defeat ASLR of a binary that
still shares your uid.

So change the access checks to the more common 'ptrace_may_access()'
model instead.

This tightens the access checks for the uid, and also effectively
changes the CAP_SYS_NICE check to CAP_SYS_PTRACE, but it's unlikely that
anybody really _uses_ this legacy system call any more (we hav ebetter
NUMA placement models these days), so I expect nobody to notice.

Famous last words.

Reported-by: Otto Ebeling <otto.ebeling@iki.fi>
Acked-by: Eric W. Biederman <ebiederm@xmission.com>
Cc: Willy Tarreau <w@1wt.eu>
Cc: stable@kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Pull x86 fixes from Thomas Gleixner:
"Another pile of small fixes and updates for x86:

- Plug a hole in the SMAP implementation which misses to clear AC on
NMI entry

- Fix the norandmaps/ADDR_NO_RANDOMIZE logic so the command line
parameter works correctly again

- Use the proper accessor in the startup64 code for next_early_pgt to
prevent accessing of invalid addresses and faulting in the early
boot code.

- Prevent CPU hotplug lock recursion in the MTRR code

- Unbreak CPU0 hotplugging

- Rename overly long CPUID bits which got introduced in this cycle

- Two commits which mark data 'const' and restrict the scope of data
and functions to file scope by making them 'static'"

* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86: Constify attribute_group structures
x86/boot/64/clang: Use fixup_pointer() to access 'next_early_pgt'
x86/elf: Remove the unnecessary ADDR_NO_RANDOMIZE checks
x86: Fix norandmaps/ADDR_NO_RANDOMIZE
x86/mtrr: Prevent CPU hotplug lock recursion
x86: Mark various structures and functions as 'static'
x86/cpufeature, kvm/svm: Rename (shorten) the new "virtualized VMSAVE/VMLOAD" CPUID flag
x86/smpboot: Unbreak CPU0 hotplug
x86/asm/64: Clear AC on NMI entries

Pull timer fixes from Thomas Gleixner:
"A few small fixes for timer drivers:

- Prevent infinite recursion in the arm architected timer driver with
ftrace

- Propagate error codes to the caller in case of failure in EM STI
driver

- Adjust a bogus loop iteration in the arm architected timer driver

- Add a missing Kconfig dependency to the pistachio clocksource to
prevent build failures

- Correctly check for IS_ERR() instead of NULL in the shared timer-of
code"

* 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
clocksource/drivers/arm_arch_timer: Avoid infinite recursion when ftrace is enabled
clocksource/drivers/Kconfig: Fix CLKSRC_PISTACHIO dependencies
clocksource/drivers/timer-of: Checking for IS_ERR() instead of NULL
clocksource/drivers/em_sti: Fix error return codes in em_sti_probe()
clocksource/drivers/arm_arch_timer: Fix mem frame loop initialization

attribute_groups are not supposed to change at runtime and none of the
groups is modified.

Mark the non-const structs as const.

[ tglx: Folded into one big patch ]

Signed-off-by: Arvind Yadav <arvind.yadav.cs@gmail.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: tony.luck@intel.com
Cc: bp@alien8.de
Link: http://lkml.kernel.org/r/1500550238-15655-2-git-send-email-arvind.yadav.cs@gmail.com

Pull perf fixes from Thomas Gleixner:
"Two fixes for the perf subsystem:

- Fix an inconsistency of RDPMC mm struct tagging across exec() which
causes RDPMC to fault.

- Correct the timestamp mechanics across IOC_DISABLE/ENABLE which
causes incorrect timestamps and total time calculations"

* 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
perf/core: Fix time on IOC_ENABLE
perf/x86: Fix RDPMC vs. mm_struct tracking

Pull clockevents fixes from Daniel Lezcano:

" - Fix error check against IS_ERR() instead of NULL for the timer-of code (Dan Carpenter)
- Fix infinite recusion with ftrace for the ARM architected timer (Ding Tianhong)
- Fix the error code return in the em_sti's probe function (Gustavo A. R. Silva)
- Fix Kconfig dependency for the pistachio driver (Matt Redfearn)
- Fix mem frame loop initialization for the ARM architected timer (Matthias Kaehlcke)"

Signed-off-by: Ingo Molnar <mingo@kernel.org>

__startup_64() is normally using fixup_pointer() to access globals in a
position-independent fashion. However 'next_early_pgt' was accessed
directly, which wasn't guaranteed to work.

Luckily GCC was generating a R_X86_64_PC32 PC-relative relocation for
'next_early_pgt', but Clang emitted a R_X86_64_32S, which led to
accessing invalid memory and rebooting the kernel.

Signed-off-by: Alexander Potapenko <glider@google.com>
Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Michael Davidson <md@google.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Fixes: c88d71508e36 ("x86/boot/64: Rewrite startup_64() in C")
Link: http://lkml.kernel.org/r/20170816190808.131748-1-glider@google.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>

Pull irq fixes from Thomas Gleixner:
"A pile of smallish changes all over the place:

- Add a missing ISB in the GIC V1 driver

- Remove an ACPI version check in the GIC V3 ITS driver

- Add the missing irq_pm_shutdown function for BRCMSTB-L2 to avoid
spurious wakeups

- Remove the artifical limitation of ITS instances to the number of
NUMA nodes which prevents utilizing the ITS hardware correctly

- Prevent a infinite parsing loop in the GIC-V3 ITS/MSI code

- Honour the force affinity argument in the GIC-V3 driver which is
required to make perf work correctly

- Correctly report allocation failures in GIC-V2/V3 to avoid using
half allocated and initialized interrupts.

- Fixup checks against nr_cpu_ids in the generic IPI code"

* 'irq-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
genirq/ipi: Fixup checks against nr_cpu_ids
genirq: Restore trigger settings in irq_modify_status()
MAINTAINERS: Remove Jason Cooper's irqchip git tree
irqchip/gic-v3-its-platform-msi: Fix msi-parent parsing loop
irqchip/gic-v3-its: Allow GIC ITS number more than MAX_NUMNODES
irqchip: brcmstb-l2: Define an irq_pm_shutdown function
irqchip/gic: Ensure we have an ISB between ack and ->handle_irq
irqchip/gic-v3-its: Remove ACPICA version check for ACPI NUMA
irqchip/gic-v3: Honor forced affinity setting
irqchip/gic-v3: Report failures in gic_irq_domain_alloc
irqchip/gic-v2: Report failures in gic_irq_domain_alloc
irqchip/atmel-aic: Remove root argument from ->fixup() prototype
irqchip/atmel-aic: Fix unbalanced refcount in aic_common_rtc_irq_fixup()
irqchip/atmel-aic: Fix unbalanced of_node_put() in aic_common_irq_fixup()

Vince reported that when we do IOC_ENABLE/IOC_DISABLE while the task
is SIGSTOP'ed state the timestamps go wobbly.

It turns out we indeed fail to correctly account time while in 'OFF'
state and doing IOC_ENABLE without getting scheduled in exposes the
problem.

Further thinking about this problem, it occurred to me that we can
suffer a similar fate when we migrate an uncore event between CPUs.
The perf_event_install() on the 'new' CPU will do add_event_to_ctx()
which will reset all the time stamp, resulting in a subsequent
update_event_times() to overwrite the total_time_* fields with smaller
values.

Reported-by: Vince Weaver <vincent.weaver@maine.edu>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@kernel.org>

Pull NFS client fixes from Anna Schumaker:
"A few more NFS client bugfixes from me for rc5.

Dros has a stable fix for flexfiles to prevent leaking the
nfs4_ff_ds_version arrays when freeing a layout, Trond fixed a
potential recovery loop situation with the TEST_STATEID operation, and
Christoph fixed up the pNFS blocklayout Kconfig options to prevent
unsafe use with kernels that don't have large block device support.
Summary:

Stable fix:
- fix leaking nfs4_ff_ds_version array

Other fixes:
- improve TEST_STATEID OLD_STATEID handling to prevent recovery loop

- require 64-bit sector_t for pNFS blocklayout to prevent 32-bit
compile errors"

* tag 'nfs-for-4.13-5' of git://git.linux-nfs.org/projects/anna/linux-nfs:
pnfs/blocklayout: require 64-bit sector_t
NFSv4: Ignore NFS4ERR_OLD_STATEID in nfs41_check_open_stateid()
nfs/flexfiles: fix leak of nfs4_ff_ds_version arrays

On platforms with an arch timer erratum workaround, it's possible for
arch_timer_reg_read_stable() to recurse into itself when certain
tracing options are enabled, leading to stack overflows and related
problems.

For example, when PREEMPT_TRACER and FUNCTION_GRAPH_TRACER are
selected, it's possible to trigger this with:

$ mount -t debugfs nodev /sys/kernel/debug/
$ echo function_graph > /sys/kernel/debug/tracing/current_tracer

The problem is that in such cases, preempt_disable() instrumentation
attempts to acquire a timestamp via trace_clock(), resulting in a call
back to arch_timer_reg_read_stable(), and hence recursion.

This patch changes arch_timer_reg_read_stable() to use
preempt_{disable,enable}_notrace(), which avoids this.

This problem is similar to the fixed by upstream commit 96b3d28bf4
("sched/clock: Prevent tracing recursion in sched_clock_cpu()").

Fixes: 6acc71ccac71 ("arm64: arch_timer: Allows a CPU-specific erratum to only affect a subset of CPUs")
Signed-off-by: Ding Tianhong <dingtianhong@huawei.com>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>

The ADDR_NO_RANDOMIZE checks in stack_maxrandom_size() and
randomize_stack_top() are not required.

PF_RANDOMIZE is set by load_elf_binary() only if ADDR_NO_RANDOMIZE is not
set, no need to re-check after that.

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Dmitry Safonov <dsafonov@virtuozzo.com>
Cc: stable@vger.kernel.org
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Borislav Petkov <bp@suse.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Link: http://lkml.kernel.org/r/20170815154011.GB1076@redhat.com

Pull watchdog fix from Thomas Gleixner:
"A fix for the hardlockup watchdog to prevent false positives with
extreme Turbo-Modes which make the perf/NMI watchdog fire faster than
the hrtimer which is used to verify.

Slightly larger than the minimal fix, which just would increase the
hrtimer frequency, but comes with extra overhead of more watchdog
timer interrupts and thread wakeups for all users.

With this change we restrict the overhead to the extreme Turbo-Mode
systems"

* 'core-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
kernel/watchdog: Prevent false positives with turbo modes