Most of the machinery is now in place to enable 52-bit kernel VAs that
are detectable at boot time.

This patch adds a Kconfig option for 52-bit user and kernel addresses
and plumbs in the requisite CONFIG_ macros as well as sets TCR.T1SZ,
physvirt_offset and vmemmap at early boot.

To simplify things this patch also removes the 52-bit user/48-bit kernel
kconfig option.
Signed-off-by: NSteve Capper <steve.capper@arm.com>
Reviewed-by: NCatalin Marinas <catalin.marinas@arm.com>
Signed-off-by: NWill Deacon <will@kernel.org>

In a later patch we will need to have a slightly larger VMEMMAP region
to accommodate boot time selection between 48/52-bit kernel VAs.

This patch modifies the formula for computing VMEMMAP_SIZE to depend
explicitly on the PAGE_OFFSET and start of kernel addressable memory.
(This allows for a slightly larger direct linear map in future).
Signed-off-by: NSteve Capper <steve.capper@arm.com>
Reviewed-by: NCatalin Marinas <catalin.marinas@arm.com>
Signed-off-by: NWill Deacon <will@kernel.org>

vmemmap is a preprocessor definition that depends on a variable,
memstart_addr. In a later patch we will need to expand the size of
the VMEMMAP region and optionally modify vmemmap depending upon
whether or not hardware support is available for 52-bit virtual
addresses.

This patch changes vmemmap to be a variable. As the old definition
depended on a variable load, this should not affect performance
noticeably.
Signed-off-by: NSteve Capper <steve.capper@arm.com>
Reviewed-by: NCatalin Marinas <catalin.marinas@arm.com>
Signed-off-by: NWill Deacon <will@kernel.org>

When running with a 52-bit userspace VA and a 48-bit kernel VA we offset
ttbr1_el1 to allow the kernel pagetables with a 52-bit PTRS_PER_PGD to
be used for both userspace and kernel.

Moving on to a 52-bit kernel VA we no longer require this offset to
ttbr1_el1 should we be running on a system with HW support for 52-bit
VAs.

This patch introduces conditional logic to offset_ttbr1 to query
SYS_ID_AA64MMFR2_EL1 whenever 52-bit VAs are selected. If there is HW
support for 52-bit VAs then the ttbr1 offset is skipped.

We choose to read a system register rather than vabits_actual because
offset_ttbr1 can be called in places where the kernel data is not
actually mapped.

Calls to offset_ttbr1 appear to be made from rarely called code paths so
this extra logic is not expected to adversely affect performance.
Signed-off-by: NSteve Capper <steve.capper@arm.com>
Reviewed-by: NCatalin Marinas <catalin.marinas@arm.com>
Signed-off-by: NWill Deacon <will@kernel.org>

In order to support 52-bit kernel addresses detectable at boot time, one
needs to know the actual VA_BITS detected. A new variable vabits_actual
is introduced in this commit and employed for the KVM hypervisor layout,
KASAN, fault handling and phys-to/from-virt translation where there
would normally be compile time constants.

In order to maintain performance in phys_to_virt, another variable
physvirt_offset is introduced.
Reviewed-by: NCatalin Marinas <catalin.marinas@arm.com>
Signed-off-by: NSteve Capper <steve.capper@arm.com>
Signed-off-by: NWill Deacon <will@kernel.org>

In order to support 52-bit kernel addresses detectable at boot time, the
kernel needs to know the most conservative VA_BITS possible should it
need to fall back to this quantity due to lack of hardware support.

A new compile time constant VA_BITS_MIN is introduced in this patch and
it is employed in the KASAN end address, KASLR, and EFI stub.

For Arm, if 52-bit VA support is unavailable the fallback is to 48-bits.

In other words: VA_BITS_MIN = min (48, VA_BITS)
Reviewed-by: NCatalin Marinas <catalin.marinas@arm.com>
Signed-off-by: NSteve Capper <steve.capper@arm.com>
Signed-off-by: NWill Deacon <will@kernel.org>

The kernel page table dumper assumes that the placement of VA regions is
constant and determined at compile time. As we are about to introduce
variable VA logic, we need to be able to determine certain regions at
boot time.

Specifically the VA_START and KASAN_SHADOW_START will depend on whether
or not the system is booted with 52-bit kernel VAs.

This patch adds logic to the kernel page table dumper s.t. these regions
can be computed at boot time.
Signed-off-by: NSteve Capper <steve.capper@arm.com>
Reviewed-by: NCatalin Marinas <catalin.marinas@arm.com>
Signed-off-by: NWill Deacon <will@kernel.org>

KASAN_SHADOW_OFFSET is a constant that is supplied to gcc as a command
line argument and affects the codegen of the inline address sanetiser.

Essentially, for an example memory access:
    *ptr1 = val;
The compiler will insert logic similar to the below:
    shadowValue = *(ptr1 >> KASAN_SHADOW_SCALE_SHIFT + KASAN_SHADOW_OFFSET)
    if (somethingWrong(shadowValue))
        flagAnError();

This code sequence is inserted into many places, thus
KASAN_SHADOW_OFFSET is essentially baked into many places in the kernel
text.

If we want to run a single kernel binary with multiple address spaces,
then we need to do this with KASAN_SHADOW_OFFSET fixed.

Thankfully, due to the way the KASAN_SHADOW_OFFSET is used to provide
shadow addresses we know that the end of the shadow region is constant
w.r.t. VA space size:
    KASAN_SHADOW_END = ~0 >> KASAN_SHADOW_SCALE_SHIFT + KASAN_SHADOW_OFFSET

This means that if we increase the size of the VA space, the start of
the KASAN region expands into lower addresses whilst the end of the
KASAN region is fixed.

Currently the arm64 code computes KASAN_SHADOW_OFFSET at build time via
build scripts with the VA size used as a parameter. (There are build
time checks in the C code too to ensure that expected values are being
derived). It is sufficient, and indeed is a simplification, to remove
the build scripts (and build time checks) entirely and instead provide
KASAN_SHADOW_OFFSET values.

This patch removes the logic to compute the KASAN_SHADOW_OFFSET in the
arm64 Makefile, and instead we adopt the approach used by x86 to supply
offset values in kConfig. To help debug/develop future VA space changes,
the Makefile logic has been preserved in a script file in the arm64
Documentation folder.
Reviewed-by: NCatalin Marinas <catalin.marinas@arm.com>
Signed-off-by: NSteve Capper <steve.capper@arm.com>
Signed-off-by: NWill Deacon <will@kernel.org>

In order to allow for a KASAN shadow that changes size at boot time, one
must fix the KASAN_SHADOW_END for both 48 & 52-bit VAs and "grow" the
start address. Also, it is highly desirable to maintain the same
function addresses in the kernel .text between VA sizes. Both of these
requirements necessitate us to flip the kernel address space halves s.t.
the direct linear map occupies the lower addresses.

This patch puts the direct linear map in the lower addresses of the
kernel VA range and everything else in the higher ranges.

We need to adjust:
 *) KASAN shadow region placement logic,
 *) KASAN_SHADOW_OFFSET computation logic,
 *) virt_to_phys, phys_to_virt checks,
 *) page table dumper.

These are all small changes, that need to take place atomically, so they
are bundled into this commit.

As part of the re-arrangement, a guard region of 2MB (to preserve
alignment for fixed map) is added after the vmemmap. Otherwise the
vmemmap could intersect with IS_ERR pointers.
Reviewed-by: NCatalin Marinas <catalin.marinas@arm.com>
Signed-off-by: NSteve Capper <steve.capper@arm.com>
Signed-off-by: NWill Deacon <will@kernel.org>

Currently there are assumptions about the alignment of VMEMMAP_START
and PAGE_OFFSET that won't be valid after this series is applied.

These assumptions are in the form of bitwise operators being used
instead of addition and subtraction when calculating addresses.

This patch replaces these bitwise operators with addition/subtraction.
Signed-off-by: NSteve Capper <steve.capper@arm.com>
Reviewed-by: NCatalin Marinas <catalin.marinas@arm.com>
Signed-off-by: NWill Deacon <will@kernel.org>

Make debug exceptions visible from RCU so that synchronize_rcu()
correctly track the debug exception handler.

This also introduces sanity checks for user-mode exceptions as same
as x86's ist_enter()/ist_exit().

The debug exception can interrupt in idle task. For example, it warns
if we put a kprobe on a function called from idle task as below.
The warning message showed that the rcu_read_lock() caused this
problem. But actually, this means the RCU is lost the context which
is already in NMI/IRQ.

  /sys/kernel/debug/tracing # echo p default_idle_call >> kprobe_events
  /sys/kernel/debug/tracing # echo 1 > events/kprobes/enable
  /sys/kernel/debug/tracing # [  135.122237]
  [  135.125035] =============================
  [  135.125310] WARNING: suspicious RCU usage
  [  135.125581] 5.2.0-08445-g9187c508bdc7 #20 Not tainted
  [  135.125904] -----------------------------
  [  135.126205] include/linux/rcupdate.h:594 rcu_read_lock() used illegally while idle!
  [  135.126839]
  [  135.126839] other info that might help us debug this:
  [  135.126839]
  [  135.127410]
  [  135.127410] RCU used illegally from idle CPU!
  [  135.127410] rcu_scheduler_active = 2, debug_locks = 1
  [  135.128114] RCU used illegally from extended quiescent state!
  [  135.128555] 1 lock held by swapper/0/0:
  [  135.128944]  #0: (____ptrval____) (rcu_read_lock){....}, at: call_break_hook+0x0/0x178
  [  135.130499]
  [  135.130499] stack backtrace:
  [  135.131192] CPU: 0 PID: 0 Comm: swapper/0 Not tainted 5.2.0-08445-g9187c508bdc7 #20
  [  135.131841] Hardware name: linux,dummy-virt (DT)
  [  135.132224] Call trace:
  [  135.132491]  dump_backtrace+0x0/0x140
  [  135.132806]  show_stack+0x24/0x30
  [  135.133133]  dump_stack+0xc4/0x10c
  [  135.133726]  lockdep_rcu_suspicious+0xf8/0x108
  [  135.134171]  call_break_hook+0x170/0x178
  [  135.134486]  brk_handler+0x28/0x68
  [  135.134792]  do_debug_exception+0x90/0x150
  [  135.135051]  el1_dbg+0x18/0x8c
  [  135.135260]  default_idle_call+0x0/0x44
  [  135.135516]  cpu_startup_entry+0x2c/0x30
  [  135.135815]  rest_init+0x1b0/0x280
  [  135.136044]  arch_call_rest_init+0x14/0x1c
  [  135.136305]  start_kernel+0x4d4/0x500
  [  135.136597]

So make debug exception visible to RCU can fix this warning.
Reported-by: NNaresh Kamboju <naresh.kamboju@linaro.org>
Acked-by: NPaul E. McKenney <paulmck@linux.ibm.com>
Signed-off-by: NMasami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: NWill Deacon <will@kernel.org>

kprobes manipulates the interrupted PSTATE for single step, and
doesn't restore it. Thus, if we put a kprobe where the pstate.D
(debug) masked, the mask will be cleared after the kprobe hits.

Moreover, in the most complicated case, this can lead a kernel
crash with below message when a nested kprobe hits.

[  152.118921] Unexpected kernel single-step exception at EL1

When the 1st kprobe hits, do_debug_exception() will be called.
At this point, debug exception (= pstate.D) must be masked (=1).
But if another kprobes hits before single-step of the first kprobe
(e.g. inside user pre_handler), it unmask the debug exception
(pstate.D = 0) and return.
Then, when the 1st kprobe setting up single-step, it saves current
DAIF, mask DAIF, enable single-step, and restore DAIF.
However, since "D" flag in DAIF is cleared by the 2nd kprobe, the
single-step exception happens soon after restoring DAIF.

This has been introduced by commit 7419333f ("arm64: kprobe:
Always clear pstate.D in breakpoint exception handler")

To solve this issue, this stores all DAIF bits and restore it
after single stepping.
Reported-by: NNaresh Kamboju <naresh.kamboju@linaro.org>
Fixes: 7419333f ("arm64: kprobe: Always clear pstate.D in breakpoint exception handler")
Reviewed-by: NJames Morse <james.morse@arm.com>
Tested-by: NJames Morse <james.morse@arm.com>
Signed-off-by: NMasami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: NWill Deacon <will@kernel.org>

When CONFIG_KASAN_SW_TAGS=n, set_tag() is compiled away. GCC throws a
warning,

mm/kasan/common.c: In function '__kasan_kmalloc':
mm/kasan/common.c:464:5: warning: variable 'tag' set but not used
[-Wunused-but-set-variable]
  u8 tag = 0xff;
     ^~~

Fix it by making __tag_set() a static inline function the same as
arch_kasan_set_tag() in mm/kasan/kasan.h for consistency because there
is a macro in arch/arm64/include/asm/kasan.h,

 #define arch_kasan_set_tag(addr, tag) __tag_set(addr, tag)

However, when CONFIG_DEBUG_VIRTUAL=n and CONFIG_SPARSEMEM_VMEMMAP=y,
page_to_virt() will call __tag_set() with incorrect type of a
parameter, so fix that as well. Also, still let page_to_virt() return
"void *" instead of "const void *", so will not need to add a similar
cast in lowmem_page_address().
Signed-off-by: NQian Cai <cai@lca.pw>
Signed-off-by: NWill Deacon <will@kernel.org>

GCC throws a warning,

arch/arm64/mm/mmu.c: In function 'pud_free_pmd_page':
arch/arm64/mm/mmu.c:1033:8: warning: variable 'pud' set but not used
[-Wunused-but-set-variable]
  pud_t pud;
        ^~~

because pud_table() is a macro and compiled away. Fix it by making it a
static inline function and for pud_sect() as well.
Signed-off-by: NQian Cai <cai@lca.pw>
Signed-off-by: NWill Deacon <will@kernel.org>

Remove rcu_read_lock()/rcu_read_unlock() from debug exception
handlers since we are sure those are not preemptible and
interrupts are off.
Acked-by: NPaul E. McKenney <paulmck@linux.ibm.com>
Signed-off-by: NMasami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: NWill Deacon <will@kernel.org>

Prohibit probing on return_address() and subroutines which
is called from return_address(), since the it is invoked from
trace_hardirqs_off() which is also kprobe blacklisted.
Reported-by: NNaresh Kamboju <naresh.kamboju@linaro.org>
Signed-off-by: NMasami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: NWill Deacon <will@kernel.org>

On a system with two security states, if SCR_EL3.FIQ is cleared,
non-secure IRQ priorities get shifted to fit the secure view but
priority masks aren't.

On such system, it turns out that GIC_PRIO_IRQON masks the priority of
normal interrupts, which obviously ends up in a hang.

Increase GIC_PRIO_IRQON value (i.e. lower priority) to make sure
interrupts are not blocked by it.

Cc: Oleg Nesterov <oleg@redhat.com>
Fixes: bd82d4bd ("arm64: Fix incorrect irqflag restore for priority masking")
Acked-by: NMarc Zyngier <marc.zyngier@arm.com>
Signed-off-by: NJulien Thierry <julien.thierry.kdev@gmail.com>
Signed-off-by: NCatalin Marinas <catalin.marinas@arm.com>
[will: fixed Fixes: tag]
Signed-off-by: NWill Deacon <will@kernel.org>

GCC throws out this warning on arm64.

drivers/firmware/efi/libstub/arm-stub.c: In function 'efi_entry':
drivers/firmware/efi/libstub/arm-stub.c:132:22: warning: variable 'si'
set but not used [-Wunused-but-set-variable]

Fix it by making free_screen_info() a static inline function.
Acked-by: NWill Deacon <will@kernel.org>
Signed-off-by: NQian Cai <cai@lca.pw>
Signed-off-by: NCatalin Marinas <catalin.marinas@arm.com>

If CTR_EL0.{CWG,ERG} are 0b0000 then they must be interpreted to have
their architecturally maximum values, which defeats the use of
FTR_HIGHER_SAFE when sanitising CPU ID registers on heterogeneous
machines.

Introduce FTR_HIGHER_OR_ZERO_SAFE so that these fields effectively
saturate at zero.

Fixes: 3c739b57 ("arm64: Keep track of CPU feature registers")
Cc: <stable@vger.kernel.org> # 4.4.x-
Reviewed-by: NSuzuki K Poulose <suzuki.poulose@arm.com>
Acked-by: NMark Rutland <mark.rutland@arm.com>
Signed-off-by: NWill Deacon <will@kernel.org>
Signed-off-by: NCatalin Marinas <catalin.marinas@arm.com>

Using an old .config in combination with "make oldconfig" can cause
an incorrect detection of the compat compiler:

$ grep CROSS_COMPILE_COMPAT .config
CONFIG_CROSS_COMPILE_COMPAT_VDSO=""

$ make oldconfig && make
arch/arm64/Makefile:58: gcc not found, check CROSS_COMPILE_COMPAT.
Stop.

Accordingly to the section 7.2 of the GNU Make manual "Syntax of
Conditionals", "When the value results from complex expansions of
variables and functions, expansions you would consider empty may
actually contain whitespace characters and thus are not seen as
empty. However, you can use the strip function to avoid interpreting
whitespace as a non-empty value."

Fix the issue adding strip to the CROSS_COMPILE_COMPAT string
evaluation.
Reported-by: NMatteo Croce <mcroce@redhat.com>
Tested-by: NMatteo Croce <mcroce@redhat.com>
Acked-by: NWill Deacon <will@kernel.org>
Signed-off-by: NVincenzo Frascino <vincenzo.frascino@arm.com>
Signed-off-by: NCatalin Marinas <catalin.marinas@arm.com>

The generic VDSO implementation uses the Y2038 safe clock_gettime64() and
clock_getres_time64() syscalls as fallback for 32bit VDSO. This breaks
seccomp setups because these syscalls might be not (yet) allowed.

Implement the 32bit variants which use the legacy syscalls and select the
variant in the core library.

The 64bit time variants are not removed because they are required for the
time64 based vdso accessors.

Fixes: 00b26474 ("lib/vdso: Provide generic VDSO implementation")
Reported-by: NSean Christopherson <sean.j.christopherson@intel.com>
Reported-by: NPaul Bolle <pebolle@tiscali.nl>
Suggested-by: NAndy Lutomirski <luto@kernel.org>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Tested-by: NVincenzo Frascino <vincenzo.frascino@arm.com>
Reviewed-by: NVincenzo Frascino <vincenzo.frascino@arm.com>
Link: https://lkml.kernel.org/r/20190728131648.971361611@linutronix.de

When fall-through warnings was enabled by default the following warnings
was starting to show up:

../arch/arm64/kernel/module.c: In function ‘apply_relocate_add’:
../arch/arm64/kernel/module.c:316:19: warning: this statement may fall
 through [-Wimplicit-fallthrough=]
    overflow_check = false;
    ~~~~~~~~~~~~~~~^~~~~~~
../arch/arm64/kernel/module.c:317:3: note: here
   case R_AARCH64_MOVW_UABS_G0:
   ^~~~
../arch/arm64/kernel/module.c:322:19: warning: this statement may fall
 through [-Wimplicit-fallthrough=]
    overflow_check = false;
    ~~~~~~~~~~~~~~~^~~~~~~
../arch/arm64/kernel/module.c:323:3: note: here
   case R_AARCH64_MOVW_UABS_G1:
   ^~~~

Rework so that the compiler doesn't warn about fall-through.

Fixes: d93512ef0f0e ("Makefile: Globally enable fall-through warning")
Signed-off-by: NAnders Roxell <anders.roxell@linaro.org>
Signed-off-by: NWill Deacon <will@kernel.org>

When fall-through warnings was enabled by default the following warning
was starting to show up:

In file included from ../include/linux/kernel.h:15,
                 from ../include/linux/list.h:9,
                 from ../include/linux/kobject.h:19,
                 from ../include/linux/of.h:17,
                 from ../include/linux/irqdomain.h:35,
                 from ../include/linux/acpi.h:13,
                 from ../arch/arm64/kernel/smp.c:9:
../arch/arm64/kernel/smp.c: In function ‘__cpu_up’:
../include/linux/printk.h:302:2: warning: this statement may fall
 through [-Wimplicit-fallthrough=]
  printk(KERN_CRIT pr_fmt(fmt), ##__VA_ARGS__)
  ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
../arch/arm64/kernel/smp.c:156:4: note: in expansion of macro ‘pr_crit’
    pr_crit("CPU%u: may not have shut down cleanly\n", cpu);
    ^~~~~~~
../arch/arm64/kernel/smp.c:157:3: note: here
   case CPU_STUCK_IN_KERNEL:
   ^~~~

Rework so that the compiler doesn't warn about fall-through.

Fixes: d93512ef0f0e ("Makefile: Globally enable fall-through warning")
Signed-off-by: NAnders Roxell <anders.roxell@linaro.org>
Signed-off-by: NWill Deacon <will@kernel.org>

Now that -Wimplicit-fallthrough is passed to GCC by default, the kernel
build has suddenly got noisy. Annotate the two fall-through cases in our
hw_breakpoint implementation, since they are both intentional.
Reported-by: NAnders Roxell <anders.roxell@linaro.org>
Signed-off-by: NWill Deacon <will@kernel.org>

Commit d968d2b8 ("ARM: 7497/1: hw_breakpoint: allow single-byte
watchpoints on all addresses") changed the validation requirements for
hardware watchpoints on arch/arm/. Update our compat layer to implement
the same relaxation.

Cc: <stable@vger.kernel.org>
Signed-off-by: NWill Deacon <will@kernel.org>

UAPI headers licensed under GPL are supposed to have exception
"WITH Linux-syscall-note" so that they can be included into non-GPL
user space application code.

The exception note is missing in some UAPI headers.

Some of them slipped in by the treewide conversion commit b2441318
("License cleanup: add SPDX GPL-2.0 license identifier to files with
no license"). Just run:

  $ git show --oneline b2441318 -- arch/x86/include/uapi/asm/

I believe they are not intentional, and should be fixed too.

This patch was generated by the following script:

  git grep -l --not -e Linux-syscall-note --and -e SPDX-License-Identifier \
    -- :arch/*/include/uapi/asm/*.h :include/uapi/ :^*/Kbuild |
  while read file
  do
          sed -i -e '/[[:space:]]OR[[:space:]]/s/\(GPL-[^[:space:]]*\)/(\1 WITH Linux-syscall-note)/g' \
          -e '/[[:space:]]or[[:space:]]/s/\(GPL-[^[:space:]]*\)/(\1 WITH Linux-syscall-note)/g' \
          -e '/[[:space:]]OR[[:space:]]/!{/[[:space:]]or[[:space:]]/!s/\(GPL-[^[:space:]]*\)/\1 WITH Linux-syscall-note/g}' $file
  done

After this patch is applied, there are 5 UAPI headers that do not contain
"WITH Linux-syscall-note". They are kept untouched since this exception
applies only to GPL variants.

  $ git grep --not -e Linux-syscall-note --and -e SPDX-License-Identifier \
    -- :arch/*/include/uapi/asm/*.h :include/uapi/ :^*/Kbuild
  include/uapi/drm/panfrost_drm.h:/* SPDX-License-Identifier: MIT */
  include/uapi/linux/batman_adv.h:/* SPDX-License-Identifier: MIT */
  include/uapi/linux/qemu_fw_cfg.h:/* SPDX-License-Identifier: BSD-3-Clause */
  include/uapi/linux/vbox_err.h:/* SPDX-License-Identifier: MIT */
  include/uapi/linux/virtio_iommu.h:/* SPDX-License-Identifier: BSD-3-Clause */
Signed-off-by: NMasahiro Yamada <yamada.masahiro@socionext.com>
Reviewed-by: NThomas Gleixner <tglx@linutronix.de>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

The i.MX8M SAI block is not compatible with the i.MX6SX one, as the
register layout has changed due to two version registers being added
at the beginning of the address map. Remove the bogus compatible.

Fixes: 8c61538d ("arm64: dts: imx8mq: Add SAI2 node")
Signed-off-by: NLucas Stach <l.stach@pengutronix.de>
Reviewed-by: NDaniel Baluta <daniel.baluta@nxp.com>
Signed-off-by: NShawn Guo <shawnguo@kernel.org>

According to i.MX8MM reference manual Rev.1, 03/2019:

SAI3_RXC pin's mux option #1 should be GPT1_CLK, NOT GPT1_CAPTURE2;
SAI3_TXFS pin's mux option #1 should be GPT1_CAPTURE2, NOT GPT1_CLK.

Fixes: c1c9d413 ("dt-bindings: imx: Add pinctrl binding doc for imx8mm")
Signed-off-by: NAnson Huang <Anson.Huang@nxp.com>
Signed-off-by: NShawn Guo <shawnguo@kernel.org>

Comparing the arm-arm's  pseudocode for AArch64.PCAlignmentFault() with
AArch64.SPAlignmentFault() shows that SP faults don't copy the faulty-SP
to FAR_EL1, but this is where we read from, and the address we provide
to user-space with the BUS_ADRALN signal.

For user-space this value will be UNKNOWN due to the previous ERET to
user-space. If the last value is preserved, on systems with KASLR or KPTI
this will be the user-space link-register left in FAR_EL1 by tramp_exit().
Fix this to retrieve the original sp_el0 value, and pass this to
do_sp_pc_fault().

SP alignment faults from EL1 will cause us to take the fault again when
trying to store the pt_regs. This eventually takes us to the overflow
stack. Remove the ESR_ELx_EC_SP_ALIGN check as we will never make it
this far.

Fixes: 60ffc30d ("arm64: Exception handling")
Signed-off-by: NJames Morse <james.morse@arm.com>
[will: change label name and fleshed out comment]
Signed-off-by: NWill Deacon <will@kernel.org>

On a CPU that doesn't support SSBS, PSTATE[12] is RES0.  In a system
where only some of the CPUs implement SSBS, we end-up losing track of
the SSBS bit across task migration.

To address this issue, let's force the SSBS bit on context switch.

Fixes: 8f04e8e6 ("arm64: ssbd: Add support for PSTATE.SSBS rather than trapping to EL3")
Signed-off-by: NMarc Zyngier <marc.zyngier@arm.com>
[will: inverted logic and added comments]
Signed-off-by: NWill Deacon <will@kernel.org>

This helper is required from generic huge_pte_alloc() which is available
when arch subscribes ARCH_WANT_GENERAL_HUGETLB. arm64 implements it's own
huge_pte_alloc() and does not depend on the generic definition. Drop this
helper which is redundant on arm64.

Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Steve Capper <Steve.Capper@arm.com>
Acked-by: NCatalin Marinas <catalin.marinas@arm.com>
Signed-off-by: NAnshuman Khandual <anshuman.khandual@arm.com>
Signed-off-by: NWill Deacon <will@kernel.org>

There are some hand-written instances of "32" to express the number
of SVE Z-registers.

Since this code was written a #define was added for this, so
convert trivial instances of this magic number as appropriate.

No functional change.
Reviewed-by: NJulien Grall <julien.grall@arm.com>
Acked-by: NCatalin Marinas <catalin.marinas@arm.com>
Signed-off-by: NDave Martin <Dave.Martin@arm.com>
Signed-off-by: NWill Deacon <will@kernel.org>

Currently we convert from FPSIMD to SVE register state in memory in
two places.

To ease future maintenance, let's consolidate this in one place.
Reviewed-by: NJulien Grall <julien.grall@arm.com>
Acked-by: NCatalin Marinas <catalin.marinas@arm.com>
Signed-off-by: NDave Martin <Dave.Martin@arm.com>
Signed-off-by: NWill Deacon <will@kernel.org>

The arm64 stacktrace code is careful to only dereference frame records
in valid stack ranges, ensuring that a corrupted frame record won't
result in a faulting access.

However, it's still possible for corrupt frame records to result in
infinite loops in the stacktrace code, which is also undesirable.

This patch ensures that we complete a stacktrace in finite time, by
keeping track of which stacks we have already completed unwinding, and
verifying that if the next frame record is on the same stack, it is at a
higher address.

As this has turned out to be particularly subtle, comments are added to
explain the procedure.
Signed-off-by: NMark Rutland <mark.rutland@arm.com>
Reviewed-by: NJames Morse <james.morse@arm.com>
Tested-by: NJames Morse <james.morse@arm.com>
Acked-by: NDave Martin <Dave.Martin@arm.com>
Acked-by: NCatalin Marinas <catalin.marinas@arm.com>
Cc: Tengfei Fan <tengfeif@codeaurora.org>
Signed-off-by: NWill Deacon <will@kernel.org>

Some common code is required by each stacktrace user to initialise
struct stackframe before the first call to unwind_frame().

In preparation for adding to the common code, this patch factors it
out into a separate function start_backtrace(), and modifies the
stacktrace callers appropriately.

No functional change.
Signed-off-by: NDave Martin <dave.martin@arm.com>
[Mark: drop tsk argument, update more callsites]
Signed-off-by: NMark Rutland <mark.rutland@arm.com>
Reviewed-by: NJames Morse <james.morse@arm.com>
Acked-by: NCatalin Marinas <catalin.marinas@arm.com>
Signed-off-by: NWill Deacon <will@kernel.org>

on_accessible_stack() and on_task_stack() shouldn't (and don't)
modify their task argument, so it can be const.

This patch adds the appropriate modifiers. Whitespace violations in the
parameter lists are fixed at the same time.

No functional change.
Acked-by: NCatalin Marinas <catalin.marinas@arm.com>
Signed-off-by: NDave Martin <dave.martin@arm.com>
[Mark: fixup const location, whitespace]
Signed-off-by: NMark Rutland <mark.rutland@arm.com>
Signed-off-by: NWill Deacon <will@kernel.org>

The recent changes to the vdso library for arm64 and the introduction of
the compat vdso library have generated some misalignment in the
Makefiles.

Cleanup the Makefiles for vdso and vdso32 libraries:
  * Removing unused rules.
  * Unifying the displayed compilation messages.
  * Simplifying the generic library inclusion path for
    arm64 vdso.

Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: NVincenzo Frascino <vincenzo.frascino@arm.com>
Signed-off-by: NWill Deacon <will@kernel.org>

Running "make" on an already compiled kernel tree will rebuild the kernel
even without any modifications:

$ make ARCH=arm64 CROSS_COMPILE=/usr/bin/aarch64-unknown-linux-gnu-
arch/arm64/Makefile:58: CROSS_COMPILE_COMPAT not defined or empty, the compat vDSO will not be built
  CALL    scripts/checksyscalls.sh
  CALL    scripts/atomic/check-atomics.sh
  VDSOCHK arch/arm64/kernel/vdso/vdso.so.dbg
  VDSOSYM include/generated/vdso-offsets.h
  CHK     include/generated/compile.h
  CC      arch/arm64/kernel/signal.o
  CC      arch/arm64/kernel/vdso.o
  CC      arch/arm64/kernel/signal32.o
  LD      arch/arm64/kernel/vdso/vdso.so.dbg
  OBJCOPY arch/arm64/kernel/vdso/vdso.so
  AS      arch/arm64/kernel/vdso/vdso.o
  AR      arch/arm64/kernel/vdso/built-in.a
  AR      arch/arm64/kernel/built-in.a
  GEN     .version
  CHK     include/generated/compile.h
  UPD     include/generated/compile.h
  CC      init/version.o
  AR      init/built-in.a
  LD      vmlinux.o

This is the same bug fixed in commit 92a47286 ("x86/boot: Fix
if_changed build flip/flop bug"). We cannot use two "if_changed" in one
target. Fix this build bug by merging two commands into one function.

Fixes: a7f71a2c ("arm64: compat: Add vDSO")
Fixes: 28b1a824 ("arm64: vdso: Substitute gettimeofday() with C implementation")
Reviewed-by: NMasahiro Yamada <yamada.masahiro@socionext.com>
Reviewed-by: NVincenzo Frascino <vincenzo.frascino@arm.com>
Tested-by: NVincenzo Frascino <vincenzo.frascino@arm.com>
Co-developed-by: NVincenzo Frascino <vincenzo.frascino@arm.com>
Signed-off-by: NVincenzo Frascino <vincenzo.frascino@arm.com>
Signed-off-by: NNaohiro Aota <naohiro.aota@wdc.com>
[will: merged in compat fix from Vincenzo and made rule names consistent]
Signed-off-by: NWill Deacon <will@kernel.org>

Prior to the introduction of Unified vDSO support and compat layer for
vDSO on arm64, AT_SYSINFO_EHDR was not defined for compat tasks.
In the current implementation, AT_SYSINFO_EHDR is defined even if the
compat vdso layer is not built, which has been shown to break Android
applications using bionic:

 | 01-01 01:22:14.097   755   755 F libc    : Fatal signal 11 (SIGSEGV),
 | code 1 (SEGV_MAPERR), fault addr 0x3cf2c96c in tid 755 (cameraserver),
 | pid 755 (cameraserver)
 | 01-01 01:22:14.112   759   759 F libc    : Fatal signal 11 (SIGSEGV),
 | code 1 (SEGV_MAPERR), fault addr 0x3cf2c96c in tid 759
 | (android.hardwar), pid 759 (android.hardwar)
 | 01-01 01:22:14.120   756   756 F libc    : Fatal signal 11 (SIGSEGV)
 | code 1 (SEGV_MAPERR), fault addr 0x3cf2c96c in tid 756 (drmserver),
 | pid 756 (drmserver)

Restore the old behaviour by making sure that AT_SYSINFO_EHDR for compat
tasks is defined only when CONFIG_COMPAT_VDSO is enabled.
Reported-by: NJohn Stultz <john.stultz@linaro.org>
Tested-by: NJohn Stultz <john.stultz@linaro.org>
Signed-off-by: NVincenzo Frascino <vincenzo.frascino@arm.com>
Signed-off-by: NWill Deacon <will@kernel.org>

We want to improve error handling while adding memory by allowing to use
arch_remove_memory() and __remove_pages() even if
CONFIG_MEMORY_HOTREMOVE is not set to e.g., implement something like:

	arch_add_memory()
	rc = do_something();
	if (rc) {
		arch_remove_memory();
	}

We won't get rid of CONFIG_MEMORY_HOTREMOVE for now, as it will require
quite some dependencies for memory offlining.

Link: http://lkml.kernel.org/r/20190527111152.16324-7-david@redhat.comSigned-off-by: NDavid Hildenbrand <david@redhat.com>
Reviewed-by: NPavel Tatashin <pasha.tatashin@soleen.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Cc: Rich Felker <dalias@libc.org>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Borislav Petkov <bp@alien8.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: "Rafael J. Wysocki" <rafael@kernel.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Oscar Salvador <osalvador@suse.com>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Alex Deucher <alexander.deucher@amd.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Mark Brown <broonie@kernel.org>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Christophe Leroy <christophe.leroy@c-s.fr>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Rob Herring <robh@kernel.org>
Cc: Masahiro Yamada <yamada.masahiro@socionext.com>
Cc: "mike.travis@hpe.com" <mike.travis@hpe.com>
Cc: Andrew Banman <andrew.banman@hpe.com>
Cc: Arun KS <arunks@codeaurora.org>
Cc: Qian Cai <cai@lca.pw>
Cc: Mathieu Malaterre <malat@debian.org>
Cc: Baoquan He <bhe@redhat.com>
Cc: Logan Gunthorpe <logang@deltatee.com>
Cc: Anshuman Khandual <anshuman.khandual@arm.com>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Chintan Pandya <cpandya@codeaurora.org>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Jun Yao <yaojun8558363@gmail.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mike Rapoport <rppt@linux.vnet.ibm.com>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Robin Murphy <robin.murphy@arm.com>
Cc: Wei Yang <richard.weiyang@gmail.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Yu Zhao <yuzhao@google.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>