When low memory doesn't reach HIGHMEM_START (e.g. up to 256MB at PA=0 is
common) and highmem is present above HIGHMEM_START (e.g. on Malta the
RAM overlayed by the IO region is aliased at PA=0x90000000), max_low_pfn
will be initially calculated very large and then clipped down to
HIGHMEM_START.

This causes crashes when reading /sys/kernel/mm/page_idle/bitmap
(i.e. CONFIG_IDLE_PAGE_TRACKING=y) when highmem is disabled. pfn_valid()
will compare against max_mapnr which is derived from max_low_pfn when
there is no highend_pfn set up, and will return true for PFNs right up
to HIGHMEM_START, even though they are beyond the end of low memory and
no page structs will actually exist for these PFNs.

This is fixed by skipping high memory regions when initially calculating
max_low_pfn if highmem is disabled, so it doesn't get clipped too high.
We also clip regions which overlap the highmem boundary when highmem is
disabled, so that max_pfn doesn't extend into highmem either.
Signed-off-by: NJames Hogan <james.hogan@imgtec.com>
Cc: Paul Burton <paul.burton@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/14490/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

Complement commit 80cbfad7 ("MIPS: Correct MIPS I FP context
layout") and correct the way Floating Point General registers are stored
in a signal context with MIPS I hardware.

Use the S.D and L.D assembly macros to have pairs of SWC1 instructions
and pairs of LWC1 instructions produced, respectively, in an arrangement
which makes the memory representation of floating-point data passed
compatible with that used by hardware SDC1 and LDC1 instructions, where
available, regardless of the hardware endianness used.  This matches the
layout used by r4k_fpu.S, ensuring run-time compatibility for MIPS I
software across all o32 hardware platforms.

Define an EX2 macro to handle exceptions from both hardware instructions
implicitly produced from S.D and L.D assembly macros.
Signed-off-by: NMaciej W. Rozycki <macro@imgtec.com>
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/14477/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

Fix a regression introduced with commit 2db9ca0a ("MIPS: Use struct
mips_abi offsets to save FP context") for MIPS I/I FP signal contexts,
by converting save/restore code to the updated internal API.  Start FGR
offsets from 0 rather than SC_FPREGS from $a0 and use $a1 rather than
the offset of SC_FPC_CSR from $a0 for the Floating Point Control/Status
Register (FCSR).

Document the new internal API and adjust assembly code formatting for
consistency.
Signed-off-by: NMaciej W. Rozycki <macro@imgtec.com>
Cc: Paul Burton <paul.burton@imgtec.com>
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/14476/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

Complement commit e50c0a8f ("Support the MIPS32 / MIPS64 DSP ASE.")
and remove the Floating Point Implementation Register (FIR) from the FP
register set recorded in a signal context with MIPS I processors too, in
line with the change applied to r4k_fpu.S.

The `sc_fpc_eir' slot is unused according to our current ABI and the FIR
register is read-only and always directly accessible from user software.

[ralf@linux-mips.org: This is also required because the next commit depends
on it.]
Signed-off-by: NMaciej W. Rozycki <macro@imgtec.com>
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/14475/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

Complement commit 0ae8dceaebe3 ("Merge with 2.3.10.") and use the local
`fault' handler to recover from FP sigcontext access violation faults,
like corresponding code does in r4k_fpu.S.  The `bad_stack' handler is
in syscall.c and is not suitable here as we want to propagate the error
condition up through the caller rather than killing the thread outright.
Signed-off-by: NMaciej W. Rozycki <macro@imgtec.com>
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/14474/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

Sanitize FCSR Cause bit handling, following a trail of past attempts:

* commit 42495484 ("MIPS: ptrace: Fix FP context restoration FCSR
regression"),

* commit 443c4403 ("MIPS: Always clear FCSR cause bits after
emulation"),

* commit 64bedffe ("MIPS: Clear [MSA]FPE CSR.Cause after
notify_die()"),

* commit b1442d39 ("MIPS: Prevent user from setting FCSR cause
bits"),

* commit b54d2901517d ("Properly handle branch delay slots in connection
with signals.").

Specifically do not mask these bits out in ptrace(2) processing and send
a SIGFPE signal instead whenever a matching pair of an FCSR Cause and
Enable bit is seen as execution of an affected context is about to
resume.  Only then clear Cause bits, and even then do not clear any bits
that are set but masked with the respective Enable bits.  Adjust Cause
bit clearing throughout code likewise, except within the FPU emulator
proper where they are set according to IEEE 754 exceptions raised as the
operation emulated executed.  Do so so that any IEEE 754 exceptions
subject to their default handling are recorded like with operations
executed by FPU hardware.
Signed-off-by: NMaciej W. Rozycki <macro@imgtec.com>
Cc: Paul Burton <paul.burton@imgtec.com>
Cc: James Hogan <james.hogan@imgtec.com>
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/14460/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

Complement commit ac9ad83b ("MIPS: prevent FP context set via ptrace
being discarded") and also initialize the FP context whenever FCSR alone
is written with a PTRACE_POKEUSR request addressing FPC_CSR, rather than
along with the full FPU register set in the case of the PTRACE_SETFPREGS
request.
Signed-off-by: NMaciej W. Rozycki <macro@imgtec.com>
Cc: Paul Burton <paul.burton@imgtec.com>
Cc: James Hogan <james.hogan@imgtec.com>
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/14459/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

Since commit 4bcc595c ("printk: reinstate KERN_CONT for printing
continuation lines") the output from TLB dumps on MIPS has been
pretty unreadable due to the lack of KERN_CONT markers. Use pr_cont to
provide the appropriate markers & restore the expected output.

Continuation is also used for the second line of each TLB entry printed
in dump_tlb.c even though it has a newline, since it is a continuation
of the interpretation of the same TLB entry. For example:

[   46.371884] Index:  0 pgmask=16kb va=77654000 asid=73 gid=00
        [ri=0 xi=0 pa=ffc18000 c=5 d=0 v=1 g=0] [ri=0 xi=0 pa=ffc1c000 c=5 d=0 v=1 g=0]
[   46.385380] Index: 12 pgmask=16kb va=004b4000 asid=73 gid=00
        [ri=0 xi=0 pa=00000000 c=0 d=0 v=0 g=0] [ri=0 xi=0 pa=ffb00000 c=5 d=1 v=1 g=0]
Signed-off-by: NJames Hogan <james.hogan@imgtec.com>
Cc: Maciej W. Rozycki <macro@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/14444/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

Since commit 4bcc595c ("printk: reinstate KERN_CONT for printing
continuation lines") the output from __show_regs() on MIPS has been
pretty unreadable due to the lack of KERN_CONT markers. Use pr_cont to
provide the appropriate markers & restore the expected register output.
Signed-off-by: NPaul Burton <paul.burton@imgtec.com>
Signed-off-by: NMatt Redfearn <matt.redfearn@imgtec.com>
Cc: Maciej W. Rozycki <macro@imgtec.com>
Cc: James Hogan <james.hogan@imgtec.com>
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/14432/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

Since commit 4bcc595c ("printk: reinstate KERN_CONT for printing
continuation lines") the output from show_code on MIPS has been
pretty unreadable due to the lack of KERN_CONT markers. Use pr_cont to
provide the appropriate markers & restore the expected output.
Signed-off-by: NMatt Redfearn <matt.redfearn@imgtec.com>
Cc: Maciej W. Rozycki <macro@imgtec.com>
Cc: James Hogan <james.hogan@imgtec.com>
Cc: Paul Burton <paul.burton@imgtec.com>
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/14431/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

Since commit 4bcc595c ("printk: reinstate KERN_CONT for printing
continuation lines") the output from show_stacktrace on MIPS has been
pretty unreadable due to the lack of KERN_CONT markers. Use pr_cont to
provide the appropriate markers & restore the expected output. Also
start a new line with printk such that the presence of timing
information does not interfere with output.
Signed-off-by: NMatt Redfearn <matt.redfearn@imgtec.com>
Cc: Maciej W. Rozycki <macro@imgtec.com>
Cc: James Hogan <james.hogan@imgtec.com>
Cc: Paul Burton <paul.burton@imgtec.com>
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/14430/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

Since commit 4bcc595c ("printk: reinstate KERN_CONT for printing
continuation lines") the output from show_backtrace on MIPS has been
pretty unreadable due to the lack of KERN_CONT markers. Use pr_cont to
provide the appropriate markers & restore the expected output.
Signed-off-by: NMatt Redfearn <matt.redfearn@imgtec.com>
Cc: Maciej W. Rozycki <macro@imgtec.com>
Cc: James Hogan <james.hogan@imgtec.com>
Cc: Paul Burton <paul.burton@imgtec.com>
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/14429/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

Changes introduced to arch/mips/Makefile for the generic kernel resulted
in build errors when making a compressed image if platform-y has multiple
values, like this:

make[2]: *** No rule to make target `alchemy/'.
make[1]: *** [vmlinuz] Error 2
make[1]: Target `_all' not remade because of errors.
make: *** [sub-make] Error 2
make: Target `_all' not remade because of errors.

Fix this by quoting $(platform-y) as it is passed to the Makefile in
arch/mips/boot/compressed/Makefile
Reported-by: Nkernelci.org bot <bot@kernelci.org>
Link: https://storage.kernelci.org/next/next-20161017/mips-gpr_defconfig/build.logSigned-off-by: NMatt Redfearn <matt.redfearn@imgtec.com>
Reviewed-by: NPaul Burton <paul.burton@imgtec.com>
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/14405/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

The KASLR code requires that the plat_get_fdt() function return the
address of the device tree, and it must be available early in the boot,
before prom_init() is called. Move the code determining the address of
the device tree into plat_get_fdt, and call that from prom_init().

The fdt pointer will be set up by plat_get_fdt() called from
relocate_kernel initially and once the relocated kernel has started,
prom_init() will use it again to determine the address in the relocated
image.

Fixes: eed0eabd ("MIPS: generic: Introduce generic DT-based board support")
Signed-off-by: NMatt Redfearn <matt.redfearn@imgtec.com>
Reviewed-by: NJames Hogan <james.hogan@imgtec.com>
Reviewed-by: NPaul Burton <paul.burton@imgtec.com>
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/14415/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

If platform code returns a NULL pointer to the FDT, initial_boot_params
will not get set to a valid pointer and attempting to find the /chosen
node in it will cause a NULL pointer dereference and the kernel to crash
immediately on startup - with no output to the console.

Fix this by checking that initial_boot_params is valid before using it.

Fixes: 405bc8fd ("MIPS: Kernel: Implement KASLR using CONFIG_RELOCATABLE")
Cc: stable@vger.kernel.org # 4.7+
Signed-off-by: NMatt Redfearn <matt.redfearn@imgtec.com>
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/14414/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

Commit 10b6ea09 ("MIPS: Malta: Use syscon-reboot driver to reboot")
converted the Malta board to use the generic syscon-reboot driver to
handle reboots, but incorrectly used the value 0x4d rather than 0x42 as
the magic to write to the reboot register.

I also incorrectly believed that syscon/regmap would default to native
endianness, but this isn't the case. Force this by specifying with a
native-endian property in the devicetree.
Signed-off-by: NPaul Burton <paul.burton@imgtec.com>
Fixes: 10b6ea09 ("MIPS: Malta: Use syscon-reboot driver to reboot")
Reported-by: NGuenter Roeck <linux@roeck-us.net>
Cc: linux-mips@linux-mips.org
Tested-by: NGuenter Roeck <linux@roeck-us.net>
Tested-by: NMaciej W. Rozycki <macro@imgtec.com>
Patchwork: https://patchwork.linux-mips.org/patch/14396/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

Provide a default implementation of mips_cpc_default_phys_base() which
simply returns 0, and adjust mips_cpc_phys_base() to allow for
mips_cpc_default_phys_base() returning 0. This allows kernels which
include CPC support to be built without platform code & simply ignore
the CPC if it wasn't already enabled by the bootloader.

This fixes link failures such as the following from generic defconfigs:

   arch/mips/built-in.o: In function `mips_cpc_phys_base':
   arch/mips/kernel/mips-cpc.c:47: undefined reference to `mips_cpc_default_phys_base'

[ralf@linux-mips.org: changed prototype for coding style compliance.]
Signed-off-by: NPaul Burton <paul.burton@imgtec.com>
Reported-by: Nkbuild test robot <fengguang.wu@intel.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/14401/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

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

LINUX_GATEWAY_ADDR is defined in unistd.h. Let's use it.
Signed-off-by: NHelge Deller <deller@gmx.de>

We have one critical section in the syscall entry path in which we switch from
the userspace stack to kernel stack. In the event of an external interrupt, the
interrupt code distinguishes between those two states by analyzing the value of
sr7. If sr7 is zero, it uses the kernel stack. Therefore it's important, that
the value of sr7 is in sync with the currently enabled stack.

This patch now disables interrupts while executing the critical section.  This
prevents the interrupt handler to possibly see an inconsistent state which in
the worst case can lead to crashes.

Interestingly, in the syscall exit path interrupts were already disabled in the
critical section which switches back to the userspace stack.

Cc: <stable@vger.kernel.org>
Signed-off-by: NJohn David Anglin <dave.anglin@bell.net>
Signed-off-by: NHelge Deller <deller@gmx.de>

There is no need to trash sr2 and sr3 in the Light-weight syscall (LWS).  sr2
already points to kernel space (it's zero in userspace, otherwise syscalls
wouldn't work), and since the LWS code is executed in userspace, we can simply
ignore to preload sr3.
Signed-off-by: NJohn David Anglin <dave.anglin@bell.net>
Signed-off-by: NHelge Deller <deller@gmx.de>

Recent changes to printk require KERN_CONT uses to continue logging messages.
So add KERN_CONT to output of device inventory.
Signed-off-by: NHelge Deller <deller@gmx.de>

Commit 01cfbad7 "ipv4: Update parameters for csum_tcpudp_magic to their
original types" changed parameters for csum_tcpudp_magic and
csum_tcpudp_nofold for many platforms but not for PowerPC.

Fixes: 01cfbad7 "ipv4: Update parameters for csum_tcpudp_magic to their original types"
Cc: Alexander Duyck <aduyck@mirantis.com>
Signed-off-by: NIvan Vecera <ivecera@redhat.com>
Acked-by: NAlexander Duyck <alexander.h.duyck@intel.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The recent changes, which forced the registration of the boot cpu on UP
systems, which do not have ACPI tables, have been fixed for systems w/o
local APIC, but left a wreckage for systems which have neither ACPI nor
mptables, but the CPU has an APIC, e.g. virtualbox.

The boot process crashes in prefill_possible_map() as it wants to register
the boot cpu, which needs to access the local apic, but the local APIC is
not yet mapped.

There is no reason why init_apic_mapping() can't be invoked before
prefill_possible_map(). So instead of playing another silly early mapping
game, as the ACPI/mptables code does, we just move init_apic_mapping()
before the call to prefill_possible_map().

In hindsight, I should have noticed that combination earlier.

Sorry for the churn (also in stable)!

Fixes: ff856051 ("x86/boot/smp: Don't try to poke disabled/non-existent APIC")
Reported-and-debugged-by: NMichal Necasek <michal.necasek@oracle.com>
Reported-and-tested-by: NWolfgang Bauer <wbauer@tmo.at>
Cc: prarit@redhat.com
Cc: ville.syrjala@linux.intel.com
Cc: michael.thayer@oracle.com
Cc: knut.osmundsen@oracle.com
Cc: frank.mehnert@oracle.com
Cc: Borislav Petkov <bp@alien8.de>
Cc: stable@vger.kernel.org
Link: http://lkml.kernel.org/r/alpine.DEB.2.20.1610282114380.5053@nanosSigned-off-by: NThomas Gleixner <tglx@linutronix.de>

Now that we have referece to section name string table in
apply_relocate_add(), use it to

 - print the name of section being relocated
 - print symbol with NULL name (since it refers to a section)

before

| Section to fixup 7000a060
| =========================================================
| rela->r_off | rela->addend | sym->st_value | ADDR | VALUE
| =========================================================
|	1c		0		7000e000  7000a07c 7000e000 []
|	40		0		7000a000  7000a0a0 7000a000 []

after

| Section to fixup .eh_frame @7000a060
| =========================================================
| r_off	r_add	st_value ADDRESS  VALUE
| =========================================================
|    1c	0	7000e000 7000a07c 7000e000 [.init.text]
|    40	0	7000a000 7000a0a0 7000a000 [.exit.text]
Signed-off-by: NVineet Gupta <vgupta@synopsys.com>

The loop was really needed in .debug_frame regime where wanted make it
as SH_ALLOC so that apply_relocate_add() would process it. That's not
needed for .eh_frame, so we check this in apply_relocate_add() which
gets called for each section.

Note that we need to save reference to "section name strings" section in
module_frob_arch_sections() since apply_relocate_add() doesn't get that
Signed-off-by: NVineet Gupta <vgupta@synopsys.com>

... given that we have perf counters abel to do the same thing non
intrusively
Signed-off-by: NVineet Gupta <vgupta@synopsys.com>

These are really ancient toggles and tools no longer require them to be
passed. This paves way for deprecating them in long run.
Signed-off-by: NVineet Gupta <vgupta@synopsys.com>

The motivation is to identify ARC750 vs. ARC770 (we currently print
generic "ARC700").

A given ARC700 release could be 750 or 770, with same ARCNUM (or family
identifier which is unfortunate). The existing arc_cpu_tbl[] kept a single
concatenated string for core name and release which thus doesn't work
for 750 vs. 770 identification.

So split this into 2 tables, one with core names and other with release.
And while we are at it, get rid of the range checking for family numbers.
We just document the known to exist cores running Linux and ditch
others.

With this in place, we add detection of ARC750 which is
 - cores 0x33 and before
 - cores 0x34 and later with MMUv2
Signed-off-by: NVineet Gupta <vgupta@synopsys.com>

Signed-off-by: NVineet Gupta <vgupta@synopsys.com>

This came to light when helping a customer with oldish ARC750 core who
were getting instruction errors because of lack of SWAPE but boot log
was incorrectly printing it as being present
Signed-off-by: NVineet Gupta <vgupta@synopsys.com>

On older arc700 cores, some of the features configured were not present
in Build config registers. To print about them at boot, we just use the
Kconfig option i.e. whether linux is built to use them or not.
So yes this seems bogus, but what else can be done. Moreover if linux is
booting with these enabled, then the Kconfig info is a good indicator
anyways.

Over time these "hacks" accumulated in read_arc_build_cfg_regs() as well
as arc_cpu_mumbojumbo(). so refactor and move all of those in a single
place: read_arc_build_cfg_regs(). This causes some code redcution too:

| bloat-o-meter2 arch/arc/kernel/setup.o.0 arch/arc/kernel/setup.o.1
| add/remove: 0/0 grow/shrink: 2/1 up/down: 64/-132 (-68)
| function                                     old     new   delta
| setup_processor                              610     670     +60
| cpuinfo_arc700                                76      80      +4
| arc_cpu_mumbojumbo                           752     620    -132
Signed-off-by: NVineet Gupta <vgupta@synopsys.com>

Previously we would not print the case when IOC existed but was not
enabled.

And while at it, reduce one line off boot printing by consolidating
the Peripheral address space and IO-Coherency which in a way
applies to them
Signed-off-by: NVineet Gupta <vgupta@synopsys.com>

perf doesn't seem to honour the number of fixed counters specified by CPUID
leaf 0xa. It always assumes that Intel CPUs have at least 3 fixed counters.

So if some of the fixed counters are masked out by the hypervisor, it still
tries to check/set them.

This patch makes perf behave nicer when the kernel is running under a
hypervisor that doesn't expose all the counters.

This patch contains some ideas from Matt Wilson.
Signed-off-by: NImre Palik <imrep@amazon.de>
Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: NAndi Kleen <ak@linux.intel.com>
Cc: Alexander Kozyrev <alexander.kozyrev@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Artyom Kuanbekov <artyom.kuanbekov@intel.com>
Cc: David Carrillo-Cisneros <davidcc@google.com>
Cc: David Woodhouse <dwmw@amazon.co.uk>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Kan Liang <kan.liang@intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Matt Wilson <msw@amazon.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1477037939-15605-1-git-send-email-imrep.amz@gmail.comSigned-off-by: NIngo Molnar <mingo@kernel.org>

The trinity syscall fuzzer triggered following WARN() on powerpc:

  WARNING: CPU: 9 PID: 2998 at arch/powerpc/kernel/hw_breakpoint.c:278
  ...
  NIP [c00000000093aedc] .hw_breakpoint_handler+0x28c/0x2b0
  LR [c00000000093aed8] .hw_breakpoint_handler+0x288/0x2b0
  Call Trace:
  [c0000002f7933580] [c00000000093aed8] .hw_breakpoint_handler+0x288/0x2b0 (unreliable)
  [c0000002f7933630] [c0000000000f671c] .notifier_call_chain+0x7c/0xf0
  [c0000002f79336d0] [c0000000000f6abc] .__atomic_notifier_call_chain+0xbc/0x1c0
  [c0000002f7933780] [c0000000000f6c40] .notify_die+0x70/0xd0
  [c0000002f7933820] [c00000000001a74c] .do_break+0x4c/0x100
  [c0000002f7933920] [c0000000000089fc] handle_dabr_fault+0x14/0x48

Followed by a lockdep warning:

  ===============================
  [ INFO: suspicious RCU usage. ]
  4.8.0-rc5+ #7 Tainted: G        W
  -------------------------------
  ./include/linux/rcupdate.h:556 Illegal context switch in RCU read-side critical section!

  other info that might help us debug this:

  rcu_scheduler_active = 1, debug_locks = 0
  2 locks held by ls/2998:
   #0:  (rcu_read_lock){......}, at: [<c0000000000f6a00>] .__atomic_notifier_call_chain+0x0/0x1c0
   #1:  (rcu_read_lock){......}, at: [<c00000000093ac50>] .hw_breakpoint_handler+0x0/0x2b0

  stack backtrace:
  CPU: 9 PID: 2998 Comm: ls Tainted: G        W       4.8.0-rc5+ #7
  Call Trace:
  [c0000002f7933150] [c00000000094b1f8] .dump_stack+0xe0/0x14c (unreliable)
  [c0000002f79331e0] [c00000000013c468] .lockdep_rcu_suspicious+0x138/0x180
  [c0000002f7933270] [c0000000001005d8] .___might_sleep+0x278/0x2e0
  [c0000002f7933300] [c000000000935584] .mutex_lock_nested+0x64/0x5a0
  [c0000002f7933410] [c00000000023084c] .perf_event_ctx_lock_nested+0x16c/0x380
  [c0000002f7933500] [c000000000230a80] .perf_event_disable+0x20/0x60
  [c0000002f7933580] [c00000000093aeec] .hw_breakpoint_handler+0x29c/0x2b0
  [c0000002f7933630] [c0000000000f671c] .notifier_call_chain+0x7c/0xf0
  [c0000002f79336d0] [c0000000000f6abc] .__atomic_notifier_call_chain+0xbc/0x1c0
  [c0000002f7933780] [c0000000000f6c40] .notify_die+0x70/0xd0
  [c0000002f7933820] [c00000000001a74c] .do_break+0x4c/0x100
  [c0000002f7933920] [c0000000000089fc] handle_dabr_fault+0x14/0x48

While it looks like the first WARN() is probably valid, the other one is
triggered by disabling event via perf_event_disable() from atomic context.

The event is disabled here in case we were not able to emulate
the instruction that hit the breakpoint. By disabling the event
we unschedule the event and make sure it's not scheduled back.

But we can't call perf_event_disable() from atomic context, instead
we need to use the event's pending_disable irq_work method to disable it.
Reported-by: NJan Stancek <jstancek@redhat.com>
Signed-off-by: NJiri Olsa <jolsa@kernel.org>
Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Huang Ying <ying.huang@intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Michael Neuling <mikey@neuling.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20161026094824.GA21397@kravaSigned-off-by: NIngo Molnar <mingo@kernel.org>

We needed the physical address of the container in order to compute the
offset within the relocated ramdisk. And we did this by doing __pa() on
the virtual address.

However, __pa() does checks whether the physical address is within
PAGE_OFFSET and __START_KERNEL_map - see __phys_addr() - which fail
if we have CONFIG_RANDOMIZE_MEMORY enabled: we feed a virtual address
which *doesn't* have the randomization offset into a function which uses
PAGE_OFFSET which *does* have that offset.

This makes this check fire:

	VIRTUAL_BUG_ON((x > y) || !phys_addr_valid(x));
			^^^^^^

due to the randomization offset.

The fix is as simple as using __pa_nodebug() because we do that
randomization offset accounting later in that function ourselves.
Reported-by: NBob Peterson <rpeterso@redhat.com>
Tested-by: NBob Peterson <rpeterso@redhat.com>
Signed-off-by: NBorislav Petkov <bp@suse.de>
Cc: Andreas Gruenbacher <agruenba@redhat.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Whitehouse <swhiteho@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-mm <linux-mm@kvack.org>
Cc: stable@vger.kernel.org # 4.9
Link: http://lkml.kernel.org/r/20161027123623.j2jri5bandimboff@pd.tnicSigned-off-by: NIngo Molnar <mingo@kernel.org>

It makes the result hard to interpret correctly if a base 10 number is
prefixed by 0x.  So change to a hex number.

Link: http://lkml.kernel.org/r/20161026125658.25728-6-u.kleine-koenig@pengutronix.deSigned-off-by: NUwe Kleine-König <u.kleine-koenig@pengutronix.de>
Cc: Mikael Starvik <starvik@axis.com>
Cc: Jesper Nilsson <jesper.nilsson@axis.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The use of config_enabled() is ambiguous.  For config options,
IS_ENABLED(), IS_REACHABLE(), etc.  will make intention clearer.
Sometimes config_enabled() has been used for non-config options because
it is useful to check whether the given symbol is defined or not.

I have been tackling on deprecating config_enabled(), and now is the
time to finish this work.

Some new users have appeared for v4.9-rc1, but it is trivial to replace
them:

 - arch/x86/mm/kaslr.c
  replace config_enabled() with IS_ENABLED() because
  CONFIG_X86_ESPFIX64 and CONFIG_EFI are boolean.

 - include/asm-generic/export.h
  replace config_enabled() with __is_defined().

Then, config_enabled() can be removed now.

Going forward, please use IS_ENABLED(), IS_REACHABLE(), etc. for config
options, and __is_defined() for non-config symbols.

Link: http://lkml.kernel.org/r/1476616078-32252-1-git-send-email-yamada.masahiro@socionext.comSigned-off-by: NMasahiro Yamada <yamada.masahiro@socionext.com>
Acked-by: NIngo Molnar <mingo@kernel.org>
Acked-by: NNicolas Pitre <nicolas.pitre@linaro.org>
Cc: Peter Oberparleiter <oberpar@linux.vnet.ibm.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Kees Cook <keescook@chromium.org>
Cc: Michal Marek <mmarek@suse.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Thomas Garnier <thgarnie@google.com>
Cc: Paul Bolle <pebolle@tiscali.nl>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Back in commit f56141e3 ("all arches, signal: move restart_block to
struct task_struct"), all architectures and core code were changed to
use task_struct::restart_block.  However, when h8300 support was
subsequently restored in v4.2, it was not updated to account for this,
and maintains thread_info::restart_block, which is not kept in sync.

This patch drops the redundant restart_block from thread_info, and moves
h8300 to the common one in task_struct, ensuring that syscall restarting
always works as expected.

Fixes: f56141e3 ("all arches, signal: move restart_block to struct task_struct")
Link: http://lkml.kernel.org/r/1476714934-11635-1-git-send-email-mark.rutland@arm.comSigned-off-by: NMark Rutland <mark.rutland@arm.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Cc: uclinux-h8-devel@lists.sourceforge.jp
Cc: <stable@vger.kernel.org>	[4.2+]
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

When the vmalloc area gets fragmented, and because the firmware
mapping area sits between where modules live and the vmalloc area, we
can sometimes receive requests for enormous kernel TLB range flushes.

When this happens the cpu just spins flushing billions of pages and
this triggers the NMI watchdog and other problems.

We took care of this on the TSB side by doing a linear scan of the
table once we pass a certain threshold.

Do something similar for the TLB flush, however we are limited by
the TLB flush facilities provided by the different chip variants.

First of all we use an (mostly arbitrary) cut-off of 256K which is
about 32 pages.  This can be tuned in the future.

The huge range code path for each chip works as follows:

1) On spitfire we flush all non-locked TLB entries using diagnostic
   acceses.

2) On cheetah we use the "flush all" TLB flush.

3) On sun4v/hypervisor we do a TLB context flush on context 0, which
   unlike previous chips does not remove "permanent" or locked
   entries.

We could probably do something better on spitfire, such as limiting
the flush to kernel TLB entries or even doing range comparisons.
However that probably isn't worth it since those chips are old and
the TLB only had 64 entries.
Reported-by: NJames Clarke <jrtc27@jrtc27.com>
Tested-by: NJames Clarke <jrtc27@jrtc27.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>