Commit Graph

120 Commits

Author SHA1 Message Date
Mark Rutland 8286824789 arm64: kasan: mte: use a constant kernel GCR_EL1 value
When KASAN_HW_TAGS is selected, KASAN is enabled at boot time, and the
hardware supports MTE, we'll initialize `kernel_gcr_excl` with a value
dependent on KASAN_TAG_MAX. While the resulting value is a constant
which depends on KASAN_TAG_MAX, we have to perform some runtime work to
generate the value, and have to read the value from memory during the
exception entry path. It would be better if we could generate this as a
constant at compile-time, and use it as such directly.

Early in boot within __cpu_setup(), we initialize GCR_EL1 to a safe
value, and later override this with the value required by KASAN. If
CONFIG_KASAN_HW_TAGS is not selected, or if KASAN is disabeld at boot
time, the kernel will not use IRG instructions, and so the initial value
of GCR_EL1 is does not matter to the kernel. Thus, we can instead have
__cpu_setup() initialize GCR_EL1 to a value consistent with
KASAN_TAG_MAX, and avoid the need to re-initialize it during hotplug and
resume form suspend.

This patch makes arem64 use a compile-time constant KERNEL_GCR_EL1
value, which is compatible with KASAN_HW_TAGS when this is selected.
This removes the need to re-initialize GCR_EL1 dynamically, and acts as
an optimization to the entry assembly, which no longer needs to load
this value from memory. The redundant initialization hooks are removed.

In order to do this, KASAN_TAG_MAX needs to be visible outside of the
core KASAN code. To do this, I've moved the KASAN_TAG_* values into
<linux/kasan-tags.h>.

There should be no functional change as a result of this patch.

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Konovalov <andreyknvl@gmail.com>
Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Peter Collingbourne <pcc@google.com>
Cc: Vincenzo Frascino <vincenzo.frascino@arm.com>
Cc: Will Deacon <will@kernel.org>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Reviewed-by: Andrey Konovalov <andreyknvl@gmail.com>
Tested-by: Andrey Konovalov <andreyknvl@gmail.com>
Link: https://lore.kernel.org/r/20210714143843.56537-3-mark.rutland@arm.com
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2021-08-02 18:14:21 +01:00
Will Deacon fdceddb06a Merge branch 'for-next/mte' into for-next/core
KASAN optimisations for the hardware tagging (MTE) implementation.

* for-next/mte:
  kasan: disable freed user page poisoning with HW tags
  arm64: mte: handle tags zeroing at page allocation time
  kasan: use separate (un)poison implementation for integrated init
  mm: arch: remove indirection level in alloc_zeroed_user_highpage_movable()
  kasan: speed up mte_set_mem_tag_range
2021-06-24 14:05:25 +01:00
Will Deacon 81ad4bb1fe Merge branch 'for-next/mm' into for-next/core
Lots of cleanup to our various page-table definitions, but also some
non-critical fixes and removal of some unnecessary memory types. The
most interesting change here is the reduction of ARCH_DMA_MINALIGN back
to 64 bytes, since we're not aware of any machines that need a higher
value with the way the code is structured (only needed for non-coherent
DMA).

* for-next/mm:
  arm64: tlb: fix the TTL value of tlb_get_level
  arm64/mm: Rename ARM64_SWAPPER_USES_SECTION_MAPS
  arm64: head: fix code comments in set_cpu_boot_mode_flag
  arm64: mm: drop unused __pa(__idmap_text_start)
  arm64: mm: fix the count comments in compute_indices
  arm64/mm: Fix ttbr0 values stored in struct thread_info for software-pan
  arm64: mm: Pass original fault address to handle_mm_fault()
  arm64/mm: Drop SECTION_[SHIFT|SIZE|MASK]
  arm64/mm: Use CONT_PMD_SHIFT for ARM64_MEMSTART_SHIFT
  arm64/mm: Drop SWAPPER_INIT_MAP_SIZE
  arm64: mm: decode xFSC in mem_abort_decode()
  arm64: mm: Add is_el1_data_abort() helper
  arm64: cache: Lower ARCH_DMA_MINALIGN to 64 (L1_CACHE_BYTES)
  arm64: mm: Remove unused support for Normal-WT memory type
  arm64: acpi: Map EFI_MEMORY_WT memory as Normal-NC
  arm64: mm: Remove unused support for Device-GRE memory type
  arm64: mm: Use better bitmap_zalloc()
  arm64/mm: Make vmemmap_free() available only with CONFIG_MEMORY_HOTPLUG
  arm64/mm: Remove [PUD|PMD]_TABLE_BIT from [pud|pmd]_bad()
  arm64/mm: Validate CONFIG_PGTABLE_LEVELS
2021-06-24 14:04:33 +01:00
Peter Collingbourne 013bb59dbb arm64: mte: handle tags zeroing at page allocation time
Currently, on an anonymous page fault, the kernel allocates a zeroed
page and maps it in user space. If the mapping is tagged (PROT_MTE),
set_pte_at() additionally clears the tags. It is, however, more
efficient to clear the tags at the same time as zeroing the data on
allocation. To avoid clearing the tags on any page (which may not be
mapped as tagged), only do this if the vma flags contain VM_MTE. This
requires introducing a new GFP flag that is used to determine whether
to clear the tags.

The DC GZVA instruction with a 0 top byte (and 0 tag) requires
top-byte-ignore. Set the TCR_EL1.{TBI1,TBID1} bits irrespective of
whether KASAN_HW is enabled.

Signed-off-by: Peter Collingbourne <pcc@google.com>
Co-developed-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Link: https://linux-review.googlesource.com/id/Id46dc94e30fe11474f7e54f5d65e7658dbdddb26
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Reviewed-by: Andrey Konovalov <andreyknvl@gmail.com>
Link: https://lore.kernel.org/r/20210602235230.3928842-4-pcc@google.com
Signed-off-by: Will Deacon <will@kernel.org>
2021-06-04 19:32:21 +01:00
Will Deacon 21cfe6edba arm64: mm: Remove unused support for Normal-WT memory type
The Normal-WT memory type is unused, so remove it and reclaim a MAIR.

Cc: Christoph Hellwig <hch@lst.de>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Link: https://lore.kernel.org/r/20210527110319.22157-4-will@kernel.org
Signed-off-by: Will Deacon <will@kernel.org>
2021-06-01 18:53:53 +01:00
Will Deacon 58cc6b72a2 arm64: mm: Remove unused support for Device-GRE memory type
The Device-GRE memory type is unused, so remove it and reclaim a MAIR.

Cc: Christoph Hellwig <hch@lst.de>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Suggested-by: Catalin Marinas <catalin.marinas@arm.com>
Link: https://lore.kernel.org/r/20210505180228.GA3874@arm.com
Link: https://lore.kernel.org/r/20210527110319.22157-2-will@kernel.org
Signed-off-by: Will Deacon <will@kernel.org>
2021-06-01 18:53:53 +01:00
Mark Rutland e176e2677c arm64: assembler: add set_this_cpu_offset
There should be no functional change as a result of this patch.

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Cc: Ard Biesheuvel <ardb@kernel.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: James Morse <james.morse@arm.com>
Cc: Marc Zyngier <maz@kernel.org>
Cc: Suzuki Poulose <suzuki.poulose@arm.com>
Cc: Will Deacon <will@kernel.org>
Reviewed-by: Ard Biesheuvel <ardb@kernel.org>
Link: https://lore.kernel.org/r/20210520115031.18509-3-mark.rutland@arm.com
Signed-off-by: Will Deacon <will@kernel.org>
2021-05-26 22:45:45 +01:00
Peter Collingbourne 37a8024d26 arm64: mte: initialize RGSR_EL1.SEED in __cpu_setup
A valid implementation choice for the ChooseRandomNonExcludedTag()
pseudocode function used by IRG is to behave in the same way as with
GCR_EL1.RRND=0. This would mean that RGSR_EL1.SEED is used as an LFSR
which must have a non-zero value in order for IRG to properly produce
pseudorandom numbers. However, RGSR_EL1 is reset to an UNKNOWN value
on soft reset and thus may reset to 0. Therefore we must initialize
RGSR_EL1.SEED to a non-zero value in order to ensure that IRG behaves
as expected.

Signed-off-by: Peter Collingbourne <pcc@google.com>
Fixes: 3b714d24ef ("arm64: mte: CPU feature detection and initial sysreg configuration")
Cc: <stable@vger.kernel.org> # 5.10
Link: https://linux-review.googlesource.com/id/I2b089b6c7d6f17ee37e2f0db7df5ad5bcc04526c
Acked-by: Mark Rutland <mark.rutland@arm.com>
Link: https://lore.kernel.org/r/20210507185905.1745402-1-pcc@google.com
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2021-05-10 18:56:25 +01:00
Mark Rutland 5cd6fa6de5 arm64: setup: name `tcr` register
In __cpu_setup we conditionally manipulate the TCR_EL1 value in x10
after previously using x10 as a scratch register for unrelated temporary
variables.

To make this a bit clearer, let's move the TCR_EL1 value into a named
register `tcr`. To simplify the register allocation, this is placed in
the highest available caller-saved scratch register, tcr.

Following the example of `mair`, we initialise the register with the
default value prior to any feature discovery, and write it to MAIR_EL1
after all feature discovery is complete, which allows us to simplify the
featuere discovery code.

The existing `mte_tcr` register is no longer needed, and is replaced by
the use of x10 as a temporary, matching the rest of the MTE feature
discovery assembly in __cpu_setup. As x20 is no longer used, the
function is now AAPCS compliant, as we've generally aimed for in our
assembly functions.

There should be no functional change as as a result of this patch.

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Cc: Marc Zyngier <maz@kernel.org>
Cc: Will Deacon <will@kernel.org>
Link: https://lore.kernel.org/r/20210326180137.43119-3-mark.rutland@arm.com
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2021-03-28 18:23:01 +01:00
Mark Rutland 776e49af60 arm64: setup: name `mair` register
In __cpu_setup we conditionally manipulate the MAIR_EL1 value in x5
before later reusing x5 as a scratch register for unrelated temporary
variables.

To make this a bit clearer, let's move the MAIR_EL1 value into a named
register `mair`. To simplify the register allocation, this is placed in
the highest available caller-saved scratch register, x17. As it is no
longer clobbered by other usage, we can write the value to MAIR_EL1 at
the end of the function as we do for TCR_EL1 rather than part-way though
feature discovery.

There should be no functional change as as a result of this patch.

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Cc: Marc Zyngier <maz@kernel.org>
Cc: Will Deacon <will@kernel.org>
Link: https://lore.kernel.org/r/20210326180137.43119-2-mark.rutland@arm.com
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2021-03-28 18:23:01 +01:00
Marc Zyngier 8cc8a32415 arm64: Turn the MMU-on sequence into a macro
Turning the MMU on is a popular sport in the arm64 kernel, and
we do it more than once, or even twice. As we are about to add
even more, let's turn it into a macro.

No expected functional change.

Signed-off-by: Marc Zyngier <maz@kernel.org>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: David Brazdil <dbrazdil@google.com>
Link: https://lore.kernel.org/r/20210208095732.3267263-4-maz@kernel.org
Signed-off-by: Will Deacon <will@kernel.org>
2021-02-08 12:51:26 +00:00
Marc Zyngier b161f92482 arm64: Fix outdated TCR setup comment
The arm64 kernel has long be able to use more than 39bit VAs.
Since day one, actually. Let's rewrite the offending comment.

Signed-off-by: Marc Zyngier <maz@kernel.org>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: David Brazdil <dbrazdil@google.com>
Link: https://lore.kernel.org/r/20210208095732.3267263-3-maz@kernel.org
Signed-off-by: Will Deacon <will@kernel.org>
2021-02-08 12:51:26 +00:00
Catalin Marinas f34d93f30d arm64: kasan: Set TCR_EL1.TBID1 when KASAN_HW_TAGS is enabled
Commit 49b3cf035e ("kasan: arm64: set TCR_EL1.TBID1 when enabled") set
the TBID1 bit for the KASAN_SW_TAGS configuration, freeing up 8 bits to
be used by PAC. With in-kernel MTE now in mainline, also set this bit
for the KASAN_HW_TAGS configuration.

Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Cc: Peter Collingbourne <pcc@google.com>
Acked-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Acked-by: Andrey Konovalov <andreyknvl@google.com>
2021-01-05 17:52:19 +00:00
Vincenzo Frascino bfc62c5985 arm64: kasan: allow enabling in-kernel MTE
Hardware tag-based KASAN relies on Memory Tagging Extension (MTE) feature
and requires it to be enabled.  MTE supports

This patch adds a new mte_enable_kernel() helper, that enables MTE in
Synchronous mode in EL1 and is intended to be called from KASAN runtime
during initialization.

The Tag Checking operation causes a synchronous data abort as a
consequence of a tag check fault when MTE is configured in synchronous
mode.

As part of this change enable match-all tag for EL1 to allow the kernel to
access user pages without faulting.  This is required because the kernel
does not have knowledge of the tags set by the user in a page.

Note: For MTE, the TCF bit field in SCTLR_EL1 affects only EL1 in a
similar way as TCF0 affects EL0.

MTE that is built on top of the Top Byte Ignore (TBI) feature hence we
enable it as part of this patch as well.

Link: https://lkml.kernel.org/r/7352b0a0899af65c2785416c8ca6bf3845b66fa1.1606161801.git.andreyknvl@google.com
Signed-off-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Co-developed-by: Andrey Konovalov <andreyknvl@google.com>
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Tested-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Branislav Rankov <Branislav.Rankov@arm.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Evgenii Stepanov <eugenis@google.com>
Cc: Kevin Brodsky <kevin.brodsky@arm.com>
Cc: Marco Elver <elver@google.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-12-22 12:55:07 -08:00
Catalin Marinas ba4259a6f8 Merge branch 'for-next/misc' into for-next/core
* for-next/misc:
  : Miscellaneous patches
  arm64: vmlinux.lds.S: Drop redundant *.init.rodata.*
  kasan: arm64: set TCR_EL1.TBID1 when enabled
  arm64: mte: optimize asynchronous tag check fault flag check
  arm64/mm: add fallback option to allocate virtually contiguous memory
  arm64/smp: Drop the macro S(x,s)
  arm64: consistently use reserved_pg_dir
  arm64: kprobes: Remove redundant kprobe_step_ctx

# Conflicts:
#	arch/arm64/kernel/vmlinux.lds.S
2020-12-09 18:04:48 +00:00
Mark Rutland 2ffac9e3fd arm64: head.S: cleanup SCTLR_ELx initialization
Let's make SCTLR_ELx initialization a bit clearer by using meaningful
names for the initialization values, following the same scheme for
SCTLR_EL1 and SCTLR_EL2.

These definitions will be used more widely in subsequent patches.

There should be no functional change as a result of this patch.

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: James Morse <james.morse@arm.com>
Cc: Will Deacon <will@kernel.org>
Link: https://lore.kernel.org/r/20201113124937.20574-5-mark.rutland@arm.com
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2020-12-02 19:44:03 +00:00
Peter Collingbourne 49b3cf035e kasan: arm64: set TCR_EL1.TBID1 when enabled
On hardware supporting pointer authentication, we previously ended up
enabling TBI on instruction accesses when tag-based ASAN was enabled,
but this was costing us 8 bits of PAC entropy, which was unnecessary
since tag-based ASAN does not require TBI on instruction accesses. Get
them back by setting TCR_EL1.TBID1.

Signed-off-by: Peter Collingbourne <pcc@google.com>
Reviewed-by: Andrey Konovalov <andreyknvl@google.com>
Link: https://linux-review.googlesource.com/id/I3dded7824be2e70ea64df0aabab9598d5aebfcc4
Link: https://lore.kernel.org/r/20f64e26fc8a1309caa446fffcb1b4e2fe9e229f.1605952129.git.pcc@google.com
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2020-11-25 16:53:19 +00:00
Mark Rutland 833be850f1 arm64: consistently use reserved_pg_dir
Depending on configuration options and specific code paths, we either
use the empty_zero_page or the configuration-dependent reserved_ttbr0
as a reserved value for TTBR{0,1}_EL1.

To simplify this code, let's always allocate and use the same
reserved_pg_dir, replacing reserved_ttbr0. Note that this is allocated
(and hence pre-zeroed), and is also marked as read-only in the kernel
Image mapping.

Keeping this separate from the empty_zero_page potentially helps with
robustness as the empty_zero_page is used in a number of cases where a
failure to map it read-only could allow it to become corrupted.

The (presently unused) swapper_pg_end symbol is also removed, and
comments are added wherever we rely on the offsets between the
pre-allocated pg_dirs to keep these cases easily identifiable.

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Cc: Will Deacon <will@kernel.org>
Link: https://lore.kernel.org/r/20201103102229.8542-1-mark.rutland@arm.com
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2020-11-10 17:30:40 +00:00
Vincenzo Frascino 3b714d24ef arm64: mte: CPU feature detection and initial sysreg configuration
Add the cpufeature and hwcap entries to detect the presence of MTE. Any
secondary CPU not supporting the feature, if detected on the boot CPU,
will be parked.

Add the minimum SCTLR_EL1 and HCR_EL2 bits for enabling MTE. The Normal
Tagged memory type is configured in MAIR_EL1 before the MMU is enabled
in order to avoid disrupting other CPUs in the CnP domain.

Signed-off-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Co-developed-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will@kernel.org>
Cc: Suzuki K Poulose <Suzuki.Poulose@arm.com>
2020-09-03 17:26:32 +01:00
Catalin Marinas 0178dc7613 arm64: mte: Use Normal Tagged attributes for the linear map
Once user space is given access to tagged memory, the kernel must be
able to clear/save/restore tags visible to the user. This is done via
the linear mapping, therefore map it as such. The new MT_NORMAL_TAGGED
index for MAIR_EL1 is initially mapped as Normal memory and later
changed to Normal Tagged via the cpufeature infrastructure. From a
mismatched attribute aliases perspective, the Tagged memory is
considered a permission and it won't lead to undefined behaviour.

Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will@kernel.org>
Cc: Suzuki K Poulose <Suzuki.Poulose@arm.com>
2020-09-03 17:26:31 +01:00
Mike Rapoport 65fddcfca8 mm: reorder includes after introduction of linux/pgtable.h
The replacement of <asm/pgrable.h> with <linux/pgtable.h> made the include
of the latter in the middle of asm includes.  Fix this up with the aid of
the below script and manual adjustments here and there.

	import sys
	import re

	if len(sys.argv) is not 3:
	    print "USAGE: %s <file> <header>" % (sys.argv[0])
	    sys.exit(1)

	hdr_to_move="#include <linux/%s>" % sys.argv[2]
	moved = False
	in_hdrs = False

	with open(sys.argv[1], "r") as f:
	    lines = f.readlines()
	    for _line in lines:
		line = _line.rstrip('
')
		if line == hdr_to_move:
		    continue
		if line.startswith("#include <linux/"):
		    in_hdrs = True
		elif not moved and in_hdrs:
		    moved = True
		    print hdr_to_move
		print line

Signed-off-by: Mike Rapoport <rppt@linux.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Cain <bcain@codeaurora.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Chris Zankel <chris@zankel.net>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Greentime Hu <green.hu@gmail.com>
Cc: Greg Ungerer <gerg@linux-m68k.org>
Cc: Guan Xuetao <gxt@pku.edu.cn>
Cc: Guo Ren <guoren@kernel.org>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Helge Deller <deller@gmx.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Ley Foon Tan <ley.foon.tan@intel.com>
Cc: Mark Salter <msalter@redhat.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Matt Turner <mattst88@gmail.com>
Cc: Max Filippov <jcmvbkbc@gmail.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Michal Simek <monstr@monstr.eu>
Cc: Nick Hu <nickhu@andestech.com>
Cc: Paul Walmsley <paul.walmsley@sifive.com>
Cc: Richard Weinberger <richard@nod.at>
Cc: Rich Felker <dalias@libc.org>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Stafford Horne <shorne@gmail.com>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Vincent Chen <deanbo422@gmail.com>
Cc: Vineet Gupta <vgupta@synopsys.com>
Cc: Will Deacon <will@kernel.org>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Link: http://lkml.kernel.org/r/20200514170327.31389-4-rppt@kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-06-09 09:39:13 -07:00
Mike Rapoport ca5999fde0 mm: introduce include/linux/pgtable.h
The include/linux/pgtable.h is going to be the home of generic page table
manipulation functions.

Start with moving asm-generic/pgtable.h to include/linux/pgtable.h and
make the latter include asm/pgtable.h.

Signed-off-by: Mike Rapoport <rppt@linux.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Cain <bcain@codeaurora.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Chris Zankel <chris@zankel.net>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Greentime Hu <green.hu@gmail.com>
Cc: Greg Ungerer <gerg@linux-m68k.org>
Cc: Guan Xuetao <gxt@pku.edu.cn>
Cc: Guo Ren <guoren@kernel.org>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Helge Deller <deller@gmx.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Ley Foon Tan <ley.foon.tan@intel.com>
Cc: Mark Salter <msalter@redhat.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Matt Turner <mattst88@gmail.com>
Cc: Max Filippov <jcmvbkbc@gmail.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Michal Simek <monstr@monstr.eu>
Cc: Nick Hu <nickhu@andestech.com>
Cc: Paul Walmsley <paul.walmsley@sifive.com>
Cc: Richard Weinberger <richard@nod.at>
Cc: Rich Felker <dalias@libc.org>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Stafford Horne <shorne@gmail.com>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Vincent Chen <deanbo422@gmail.com>
Cc: Vineet Gupta <vgupta@synopsys.com>
Cc: Will Deacon <will@kernel.org>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Link: http://lkml.kernel.org/r/20200514170327.31389-3-rppt@kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-06-09 09:39:13 -07:00
Will Deacon 082af5ec50 Merge branch 'for-next/scs' into for-next/core
Support for Clang's Shadow Call Stack in the kernel
(Sami Tolvanen and Will Deacon)
* for-next/scs:
  arm64: entry-ftrace.S: Update comment to indicate that x18 is live
  scs: Move DEFINE_SCS macro into core code
  scs: Remove references to asm/scs.h from core code
  scs: Move scs_overflow_check() out of architecture code
  arm64: scs: Use 'scs_sp' register alias for x18
  scs: Move accounting into alloc/free functions
  arm64: scs: Store absolute SCS stack pointer value in thread_info
  efi/libstub: Disable Shadow Call Stack
  arm64: scs: Add shadow stacks for SDEI
  arm64: Implement Shadow Call Stack
  arm64: Disable SCS for hypervisor code
  arm64: vdso: Disable Shadow Call Stack
  arm64: efi: Restore register x18 if it was corrupted
  arm64: Preserve register x18 when CPU is suspended
  arm64: Reserve register x18 from general allocation with SCS
  scs: Disable when function graph tracing is enabled
  scs: Add support for stack usage debugging
  scs: Add page accounting for shadow call stack allocations
  scs: Add support for Clang's Shadow Call Stack (SCS)
2020-05-28 18:03:40 +01:00
Sami Tolvanen 6d37d81f44 arm64: Preserve register x18 when CPU is suspended
Don't lose the current task's shadow stack when the CPU is suspended.

Signed-off-by: Sami Tolvanen <samitolvanen@google.com>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Mark Rutland <mark.rutland@arm.com>
Acked-by: Will Deacon <will@kernel.org>
Signed-off-by: Will Deacon <will@kernel.org>
2020-05-15 16:35:50 +01:00
Mark Rutland 62a679cb28 arm64: simplify ptrauth initialization
Currently __cpu_setup conditionally initializes the address
authentication keys and enables them in SCTLR_EL1, doing so differently
for the primary CPU and secondary CPUs, and skipping this work for CPUs
returning from an idle state. For the latter case, cpu_do_resume
restores the keys and SCTLR_EL1 value after the MMU has been enabled.

This flow is rather difficult to follow, so instead let's move the
primary and secondary CPU initialization into their respective boot
paths. By following the example of cpu_do_resume and doing so once the
MMU is enabled, we can always initialize the keys from the values in
thread_struct, and avoid the machinery necessary to pass the keys in
secondary_data or open-coding initialization for the boot CPU.

This means we perform an additional RMW of SCTLR_EL1, but we already do
this in the cpu_do_resume path, and for other features in cpufeature.c,
so this isn't a major concern in a bringup path. Note that even while
the enable bits are clear, the key registers are accessible.

As this now renders the argument to __cpu_setup redundant, let's also
remove that entirely. Future extensions can follow a similar approach to
initialize values that differ for primary/secondary CPUs.

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Tested-by: Amit Daniel Kachhap <amit.kachhap@arm.com>
Reviewed-by: Amit Daniel Kachhap <amit.kachhap@arm.com>
Cc: Amit Daniel Kachhap <amit.kachhap@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: James Morse <james.morse@arm.com>
Cc: Suzuki K Poulose <suzuki.poulose@arm.com>
Cc: Will Deacon <will@kernel.org>
Link: https://lore.kernel.org/r/20200423101606.37601-3-mark.rutland@arm.com
Signed-off-by: Will Deacon <will@kernel.org>
2020-04-28 11:23:21 +01:00
Mark Rutland d0055da526 arm64: remove ptrauth_keys_install_kernel sync arg
The 'sync' argument to ptrauth_keys_install_kernel macro is somewhat
opaque at callsites, so instead lets have regular and _nosync variants
of the macro to make this a little more obvious.

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Cc: Amit Daniel Kachhap <amit.kachhap@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will@kernel.org>
Link: https://lore.kernel.org/r/20200423101606.37601-2-mark.rutland@arm.com
Signed-off-by: Will Deacon <will@kernel.org>
2020-04-28 11:23:21 +01:00
Catalin Marinas 44ca0e00b6 Merge branch 'for-next/kernel-ptrauth' into for-next/core
* for-next/kernel-ptrauth:
  : Return address signing - in-kernel support
  arm64: Kconfig: verify binutils support for ARM64_PTR_AUTH
  lkdtm: arm64: test kernel pointer authentication
  arm64: compile the kernel with ptrauth return address signing
  kconfig: Add support for 'as-option'
  arm64: suspend: restore the kernel ptrauth keys
  arm64: __show_regs: strip PAC from lr in printk
  arm64: unwind: strip PAC from kernel addresses
  arm64: mask PAC bits of __builtin_return_address
  arm64: initialize ptrauth keys for kernel booting task
  arm64: initialize and switch ptrauth kernel keys
  arm64: enable ptrauth earlier
  arm64: cpufeature: handle conflicts based on capability
  arm64: cpufeature: Move cpu capability helpers inside C file
  arm64: ptrauth: Add bootup/runtime flags for __cpu_setup
  arm64: install user ptrauth keys at kernel exit time
  arm64: rename ptrauth key structures to be user-specific
  arm64: cpufeature: add pointer auth meta-capabilities
  arm64: cpufeature: Fix meta-capability cpufeature check
2020-03-25 11:11:08 +00:00
Catalin Marinas 806dc825f0 Merge branch 'for-next/asm-cleanups' into for-next/core
* for-next/asm-cleanups:
  : Various asm clean-ups (alignment, mov_q vs ldr, .idmap)
  arm64: move kimage_vaddr to .rodata
  arm64: use mov_q instead of literal ldr
2020-03-25 11:10:51 +00:00
Catalin Marinas da12d2739f Merge branches 'for-next/memory-hotremove', 'for-next/arm_sdei', 'for-next/amu', 'for-next/final-cap-helper', 'for-next/cpu_ops-cleanup', 'for-next/misc' and 'for-next/perf' into for-next/core
* for-next/memory-hotremove:
  : Memory hot-remove support for arm64
  arm64/mm: Enable memory hot remove
  arm64/mm: Hold memory hotplug lock while walking for kernel page table dump

* for-next/arm_sdei:
  : SDEI: fix double locking on return from hibernate and clean-up
  firmware: arm_sdei: clean up sdei_event_create()
  firmware: arm_sdei: Use cpus_read_lock() to avoid races with cpuhp
  firmware: arm_sdei: fix possible double-lock on hibernate error path
  firmware: arm_sdei: fix double-lock on hibernate with shared events

* for-next/amu:
  : ARMv8.4 Activity Monitors support
  clocksource/drivers/arm_arch_timer: validate arch_timer_rate
  arm64: use activity monitors for frequency invariance
  cpufreq: add function to get the hardware max frequency
  Documentation: arm64: document support for the AMU extension
  arm64/kvm: disable access to AMU registers from kvm guests
  arm64: trap to EL1 accesses to AMU counters from EL0
  arm64: add support for the AMU extension v1

* for-next/final-cap-helper:
  : Introduce cpus_have_final_cap_helper(), migrate arm64 KVM to it
  arm64: kvm: hyp: use cpus_have_final_cap()
  arm64: cpufeature: add cpus_have_final_cap()

* for-next/cpu_ops-cleanup:
  : cpu_ops[] access code clean-up
  arm64: Introduce get_cpu_ops() helper function
  arm64: Rename cpu_read_ops() to init_cpu_ops()
  arm64: Declare ACPI parking protocol CPU operation if needed

* for-next/misc:
  : Various fixes and clean-ups
  arm64: define __alloc_zeroed_user_highpage
  arm64/kernel: Simplify __cpu_up() by bailing out early
  arm64: remove redundant blank for '=' operator
  arm64: kexec_file: Fixed code style.
  arm64: add blank after 'if'
  arm64: fix spelling mistake "ca not" -> "cannot"
  arm64: entry: unmask IRQ in el0_sp()
  arm64: efi: add efi-entry.o to targets instead of extra-$(CONFIG_EFI)
  arm64: csum: Optimise IPv6 header checksum
  arch/arm64: fix typo in a comment
  arm64: remove gratuitious/stray .ltorg stanzas
  arm64: Update comment for ASID() macro
  arm64: mm: convert cpu_do_switch_mm() to C
  arm64: fix NUMA Kconfig typos

* for-next/perf:
  : arm64 perf updates
  arm64: perf: Add support for ARMv8.5-PMU 64-bit counters
  KVM: arm64: limit PMU version to PMUv3 for ARMv8.1
  arm64: cpufeature: Extract capped perfmon fields
  arm64: perf: Clean up enable/disable calls
  perf: arm-ccn: Use scnprintf() for robustness
  arm64: perf: Support new DT compatibles
  arm64: perf: Refactor PMU init callbacks
  perf: arm_spe: Remove unnecessary zero check on 'nr_pages'
2020-03-25 11:10:32 +00:00
Remi Denis-Courmont dc374b477f arm64: use mov_q instead of literal ldr
In practice, this requires only 2 instructions, or even only 1 for
the idmap_pg_dir size (with 4 or 64 KiB pages). Only the MAIR values
needed more than 2 instructions and it was already converted to mov_q
by 95b3f74bec.

Signed-off-by: Remi Denis-Courmont <remi.denis.courmont@huawei.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: Mark Rutland <mark.rutland@arm.com>
2020-03-24 11:48:24 +00:00
Amit Daniel Kachhap e51f5f56dd arm64: suspend: restore the kernel ptrauth keys
This patch restores the kernel keys from current task during cpu resume
after the mmu is turned on and ptrauth is enabled.

A flag is added in macro ptrauth_keys_install_kernel to check if isb
instruction needs to be executed.

Signed-off-by: Amit Daniel Kachhap <amit.kachhap@arm.com>
Reviewed-by: Vincenzo Frascino <Vincenzo.Frascino@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2020-03-18 09:50:21 +00:00
Kristina Martsenko 33e4523498 arm64: initialize and switch ptrauth kernel keys
Set up keys to use pointer authentication within the kernel. The kernel
will be compiled with APIAKey instructions, the other keys are currently
unused. Each task is given its own APIAKey, which is initialized during
fork. The key is changed during context switch and on kernel entry from
EL0.

The keys for idle threads need to be set before calling any C functions,
because it is not possible to enter and exit a function with different
keys.

Reviewed-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Reviewed-by: Vincenzo Frascino <Vincenzo.Frascino@arm.com>
Signed-off-by: Kristina Martsenko <kristina.martsenko@arm.com>
[Amit: Modified secondary cores key structure, comments]
Signed-off-by: Amit Daniel Kachhap <amit.kachhap@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2020-03-18 09:50:20 +00:00
Kristina Martsenko 6982934e19 arm64: enable ptrauth earlier
When the kernel is compiled with pointer auth instructions, the boot CPU
needs to start using address auth very early, so change the cpucap to
account for this.

Pointer auth must be enabled before we call C functions, because it is
not possible to enter a function with pointer auth disabled and exit it
with pointer auth enabled. Note, mismatches between architected and
IMPDEF algorithms will still be caught by the cpufeature framework (the
separate *_ARCH and *_IMP_DEF cpucaps).

Note the change in behavior: if the boot CPU has address auth and a
late CPU does not, then the late CPU is parked by the cpufeature
framework. This is possible as kernel will only have NOP space intructions
for PAC so such mismatched late cpu will silently ignore those
instructions in C functions. Also, if the boot CPU does not have address
auth and the late CPU has then the late cpu will still boot but with
ptrauth feature disabled.

Leave generic authentication as a "system scope" cpucap for now, since
initially the kernel will only use address authentication.

Reviewed-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Reviewed-by: Vincenzo Frascino <Vincenzo.Frascino@arm.com>
Signed-off-by: Kristina Martsenko <kristina.martsenko@arm.com>
[Amit: Re-worked ptrauth setup logic, comments]
Signed-off-by: Amit Daniel Kachhap <amit.kachhap@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2020-03-18 09:50:19 +00:00
Amit Daniel Kachhap df3551011b arm64: ptrauth: Add bootup/runtime flags for __cpu_setup
This patch allows __cpu_setup to be invoked with one of these flags,
ARM64_CPU_BOOT_PRIMARY, ARM64_CPU_BOOT_SECONDARY or ARM64_CPU_RUNTIME.
This is required as some cpufeatures need different handling during
different scenarios.

The input parameter in x0 is preserved till the end to be used inside
this function.

There should be no functional change with this patch and is useful
for the subsequent ptrauth patch which utilizes it. Some upcoming
arm cpufeatures can also utilize these flags.

Suggested-by: James Morse <james.morse@arm.com>
Signed-off-by: Amit Daniel Kachhap <amit.kachhap@arm.com>
Reviewed-by: Vincenzo Frascino <Vincenzo.Frascino@arm.com>
Reviewed-by: James Morse <james.morse@arm.com>
Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2020-03-18 09:50:19 +00:00
Ionela Voinescu 87a1f06346 arm64: trap to EL1 accesses to AMU counters from EL0
The activity monitors extension is an optional extension introduced
by the ARMv8.4 CPU architecture. In order to access the activity
monitors counters safely, if desired, the kernel should detect the
presence of the extension through the feature register, and mediate
the access.

Therefore, disable direct accesses to activity monitors counters
from EL0 (userspace) and trap them to EL1 (kernel).

To be noted that the ARM64_AMU_EXTN kernel config does not have an
effect on this code. Given that the amuserenr_el0 resets to an
UNKNOWN value, setting the trap of EL0 accesses to EL1 is always
attempted for safety and security considerations. Therefore firmware
should still ensure accesses to AMU registers are not trapped in
EL2/EL3 as this code cannot be bypassed if the CPU implements the
Activity Monitors Unit.

Signed-off-by: Ionela Voinescu <ionela.voinescu@arm.com>
Reviewed-by: James Morse <james.morse@arm.com>
Reviewed-by: Valentin Schneider <valentin.schneider@arm.com>
Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Cc: Steve Capper <steve.capper@arm.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Will Deacon <will@kernel.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2020-03-06 16:02:50 +00:00
Mark Rutland 25b92693a1 arm64: mm: convert cpu_do_switch_mm() to C
There's no reason that cpu_do_switch_mm() needs to be written as an
assembly function, and having it as a C function would make it easier to
maintain.

This patch converts cpu_do_switch_mm() to C, removing code that this
change makes redundant (e.g. the mmid macro). Since the header comment
was stale and the prototype now implies all the necessary information,
this comment is removed. The 'pgd_phys' argument is made a phys_addr_t
to match the return type of virt_to_phys().

At the same time, post_ttbr_update_workaround() is updated to use
IS_ENABLED(), which allows the compiler to figure out it can elide calls
for !CONFIG_CAVIUM_ERRATUM_27456 builds.

There should be no functional change as a result of this patch.

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Cc: Will Deacon <will@kernel.org>
[catalin.marinas@arm.com: change comments from asm-style to C-style]
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2020-02-27 14:30:50 +00:00
Will Deacon aa246c056c Merge branch 'for-next/asm-annotations' into for-next/core
* for-next/asm-annotations: (6 commits)
  arm64: kernel: Correct annotation of end of el0_sync
  ...
2020-01-22 11:34:21 +00:00
Will Deacon 4f6cdf296c Merge branches 'for-next/acpi', 'for-next/cpufeatures', 'for-next/csum', 'for-next/e0pd', 'for-next/entry', 'for-next/kbuild', 'for-next/kexec/cleanup', 'for-next/kexec/file-kdump', 'for-next/misc', 'for-next/nofpsimd', 'for-next/perf' and 'for-next/scs' into for-next/core
* for-next/acpi:
  ACPI/IORT: Fix 'Number of IDs' handling in iort_id_map()

* for-next/cpufeatures: (2 commits)
  arm64: Introduce ID_ISAR6 CPU register
  ...

* for-next/csum: (2 commits)
  arm64: csum: Fix pathological zero-length calls
  ...

* for-next/e0pd: (7 commits)
  arm64: kconfig: Fix alignment of E0PD help text
  ...

* for-next/entry: (5 commits)
  arm64: entry: cleanup sp_el0 manipulation
  ...

* for-next/kbuild: (4 commits)
  arm64: kbuild: remove compressed images on 'make ARCH=arm64 (dist)clean'
  ...

* for-next/kexec/cleanup: (11 commits)
  Revert "arm64: kexec: make dtb_mem always enabled"
  ...

* for-next/kexec/file-kdump: (2 commits)
  arm64: kexec_file: add crash dump support
  ...

* for-next/misc: (12 commits)
  arm64: entry: Avoid empty alternatives entries
  ...

* for-next/nofpsimd: (7 commits)
  arm64: nofpsmid: Handle TIF_FOREIGN_FPSTATE flag cleanly
  ...

* for-next/perf: (2 commits)
  perf/imx_ddr: Fix cpu hotplug state cleanup
  ...

* for-next/scs: (6 commits)
  arm64: kernel: avoid x18 in __cpu_soft_restart
  ...
2020-01-22 11:32:31 +00:00
Catalin Marinas 95b3f74bec arm64: Use macros instead of hard-coded constants for MAIR_EL1
Currently, the arm64 __cpu_setup has hard-coded constants for the memory
attributes that go into the MAIR_EL1 register. Define proper macros in
asm/sysreg.h and make use of them in proc.S.

Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Will Deacon <will@kernel.org>
2020-01-17 12:48:33 +00:00
Sami Tolvanen e3ec6582d1 arm64: mm: avoid x18 in idmap_kpti_install_ng_mappings
idmap_kpti_install_ng_mappings uses x18 as a temporary register, which
will result in a conflict when x18 is reserved. Use x16 and x17 instead
where needed.

Signed-off-by: Sami Tolvanen <samitolvanen@google.com>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Reviewed-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Will Deacon <will@kernel.org>
2020-01-16 17:32:56 +00:00
Mark Brown f4659254a3 arm64: mm: Use modern annotations for assembly functions
In an effort to clarify and simplify the annotation of assembly functions
in the kernel new macros have been introduced. These replace ENTRY and
ENDPROC and also add a new annotation for static functions which previously
had no ENTRY equivalent. Update the annotations in the mm code to the
new macros. Even the functions called from non-standard environments
like idmap have no special requirements on their environments so can be
treated like regular functions.

Signed-off-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Will Deacon <will@kernel.org>
2020-01-08 12:23:38 +00:00
Will Deacon ac12cf85d6 Merge branches 'for-next/52-bit-kva', 'for-next/cpu-topology', 'for-next/error-injection', 'for-next/perf', 'for-next/psci-cpuidle', 'for-next/rng', 'for-next/smpboot', 'for-next/tbi' and 'for-next/tlbi' into for-next/core
* for-next/52-bit-kva: (25 commits)
  Support for 52-bit virtual addressing in kernel space

* for-next/cpu-topology: (9 commits)
  Move CPU topology parsing into core code and add support for ACPI 6.3

* for-next/error-injection: (2 commits)
  Support for function error injection via kprobes

* for-next/perf: (8 commits)
  Support for i.MX8 DDR PMU and proper SMMUv3 group validation

* for-next/psci-cpuidle: (7 commits)
  Move PSCI idle code into a new CPUidle driver

* for-next/rng: (4 commits)
  Support for 'rng-seed' property being passed in the devicetree

* for-next/smpboot: (3 commits)
  Reduce fragility of secondary CPU bringup in debug configurations

* for-next/tbi: (10 commits)
  Introduce new syscall ABI with relaxed requirements for pointer tags

* for-next/tlbi: (6 commits)
  Handle spurious page faults arising from kernel space
2019-08-30 12:46:12 +01:00
Mark Rutland f32c7a8e45 arm64: kpti: ensure patched kernel text is fetched from PoU
While the MMUs is disabled, I-cache speculation can result in
instructions being fetched from the PoC. During boot we may patch
instructions (e.g. for alternatives and jump labels), and these may be
dirty at the PoU (and stale at the PoC).

Thus, while the MMU is disabled in the KPTI pagetable fixup code we may
load stale instructions into the I-cache, potentially leading to
subsequent crashes when executing regions of code which have been
modified at runtime.

Similarly to commit:

  8ec4198743 ("arm64: mm: ensure patched kernel text is fetched from PoU")

... we can invalidate the I-cache after enabling the MMU to prevent such
issues.

The KPTI pagetable fixup code itself should be clean to the PoC per the
boot protocol, so no maintenance is required for this code.

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Reviewed-by: James Morse <james.morse@arm.com>
Signed-off-by: Will Deacon <will@kernel.org>
2019-08-28 13:40:08 +01:00
Steve Capper 2c624fe687 arm64: mm: Remove vabits_user
Previous patches have enabled 52-bit kernel + user VAs and there is no
longer any scenario where user VA != kernel VA size.

This patch removes the, now redundant, vabits_user variable and replaces
usage with vabits_actual where appropriate.

Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Steve Capper <steve.capper@arm.com>
Signed-off-by: Will Deacon <will@kernel.org>
2019-08-09 11:17:27 +01:00
Steve Capper b6d00d47e8 arm64: mm: Introduce 52-bit Kernel VAs
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: Steve Capper <steve.capper@arm.com>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Will Deacon <will@kernel.org>
2019-08-09 11:17:26 +01:00
Steve Capper c812026c54 arm64: mm: Logic to make offset_ttbr1 conditional
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: Steve Capper <steve.capper@arm.com>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Will Deacon <will@kernel.org>
2019-08-09 11:17:24 +01:00
Thomas Gleixner caab277b1d treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 234
Based on 1 normalized pattern(s):

  this program is free software you can redistribute it and or modify
  it under the terms of the gnu general public license version 2 as
  published by the free software foundation this program is
  distributed in the hope that it will be useful but without any
  warranty without even the implied warranty of merchantability or
  fitness for a particular purpose see the gnu general public license
  for more details you should have received a copy of the gnu general
  public license along with this program if not see http www gnu org
  licenses

extracted by the scancode license scanner the SPDX license identifier

  GPL-2.0-only

has been chosen to replace the boilerplate/reference in 503 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Alexios Zavras <alexios.zavras@intel.com>
Reviewed-by: Allison Randal <allison@lohutok.net>
Reviewed-by: Enrico Weigelt <info@metux.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190602204653.811534538@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-06-19 17:09:07 +02:00
Jean-Philippe Brucker 827a108e35 arm64: Save and restore OSDLR_EL1 across suspend/resume
When the CPU comes out of suspend, the firmware may have modified the OS
Double Lock Register. Save it in an unused slot of cpu_suspend_ctx, and
restore it on resume.

Cc: <stable@vger.kernel.org>
Signed-off-by: Jean-Philippe Brucker <jean-philippe.brucker@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
2019-04-09 12:39:13 +01:00
Zhang Lei 3e32131abc arm64: Add workaround for Fujitsu A64FX erratum 010001
On the Fujitsu-A64FX cores ver(1.0, 1.1), memory access may cause
an undefined fault (Data abort, DFSC=0b111111). This fault occurs under
a specific hardware condition when a load/store instruction performs an
address translation. Any load/store instruction, except non-fault access
including Armv8 and SVE might cause this undefined fault.

The TCR_ELx.NFD1 bit is used by the kernel when CONFIG_RANDOMIZE_BASE
is enabled to mitigate timing attacks against KASLR where the kernel
address space could be probed using the FFR and suppressed fault on
SVE loads.

Since this erratum causes spurious exceptions, which may corrupt
the exception registers, we clear the TCR_ELx.NFDx=1 bits when
booting on an affected CPU.

Signed-off-by: Zhang Lei <zhang.lei@jp.fujitsu.com>
[Generated MIDR value/mask for __cpu_setup(), removed spurious-fault handler
 and always disabled the NFDx bits on affected CPUs]
Signed-off-by: James Morse <james.morse@arm.com>
Tested-by: zhang.lei <zhang.lei@jp.fujitsu.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2019-02-28 16:24:25 +00:00
Julien Thierry a9806aa259 arm64: Unmask PMR before going idle
CPU does not received signals for interrupts with a priority masked by
ICC_PMR_EL1. This means the CPU might not come back from a WFI
instruction.

Make sure ICC_PMR_EL1 does not mask interrupts when doing a WFI.

Since the logic of cpu_do_idle is becoming a bit more complex than just
two instructions, lets turn it from ASM to C.

Signed-off-by: Julien Thierry <julien.thierry@arm.com>
Suggested-by: Daniel Thompson <daniel.thompson@linaro.org>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Reviewed-by: Marc Zyngier <marc.zyngier@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2019-02-06 10:05:18 +00:00