Commit graph

856120 commits

Author SHA1 Message Date
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
Joakim Zhang
3724e186fe docs/perf: Add documentation for the i.MX8 DDR PMU
Add some documentation describing the DDR PMU residing in the Freescale
i.MDX SoC and its perf driver implementation in Linux.

Signed-off-by: Joakim Zhang <qiangqing.zhang@nxp.com>
Signed-off-by: Will Deacon <will@kernel.org>
2019-08-28 14:32:00 +01:00
Joakim Zhang
c12c0288e3 perf/imx_ddr: Add support for AXI ID filtering
AXI filtering is used by events 0x41 and 0x42 to count reads or writes
with an ARID or AWID matching a specified filter. The filter is exposed
to userspace as an (ID, MASK) pair, where each set bit in the mask
causes the corresponding bit in the ID to be ignored when matching
against the ID of memory transactions for the purposes of incrementing
the counter.

For example:

  # perf stat -a -e imx8_ddr0/axid-read,axi_mask=0xff,axi_id=0x800/ cmd

will count all read transactions from AXI IDs 0x800 - 0x8ff. If the
'axi_mask' is omitted, then it is treated as 0x0 which means that the
'axi_id' will be matched exactly.

Signed-off-by: Joakim Zhang <qiangqing.zhang@nxp.com>
Signed-off-by: Will Deacon <will@kernel.org>
2019-08-28 14:16:55 +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
Mark Rutland
b333b0ba23 arm64: fix fixmap copy for 16K pages and 48-bit VA
With 16K pages and 48-bit VAs, the PGD level of table has two entries,
and so the fixmap shares a PGD with the kernel image. Since commit:

  f9040773b7 ("arm64: move kernel image to base of vmalloc area")

... we copy the existing fixmap to the new fine-grained page tables at
the PUD level in this case. When walking to the new PUD, we forgot to
offset the PGD entry and always used the PGD entry at index 0, but this
worked as the kernel image and fixmap were in the low half of the TTBR1
address space.

As of commit:

  14c127c957 ("arm64: mm: Flip kernel VA space")

... the kernel image and fixmap are in the high half of the TTBR1
address space, and hence use the PGD at index 1, but we didn't update
the fixmap copying code to account for this.

Thus, we'll erroneously try to copy the fixmap slots into a PUD under
the PGD entry at index 0. At the point we do so this PGD entry has not
been initialised, and thus we'll try to write a value to a small offset
from physical address 0, causing a number of potential problems.

Fix this be correctly offsetting the PGD. This is split over a few steps
for legibility.

Fixes: 14c127c957 ("arm64: mm: Flip kernel VA space")
Reported-by: Anshuman Khandual <anshuman.khandual@arm.com>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Acked-by: Marc Zyngier <maz@kernel.org>
Tested-by: Marc Zyngier <maz@kernel.org>
Acked-by: Steve Capper <Steve.Capper@arm.com>
Tested-by: Steve Capper <Steve.Capper@arm.com>
Tested-by: Anshuman Khandual <anshuman.khandual@arm.com>
Signed-off-by: Will Deacon <will@kernel.org>
2019-08-28 12:10:03 +01:00
Robin Murphy
3c9347351a perf/smmuv3: Validate groups for global filtering
With global filtering, it becomes possible for users to construct
self-contradictory groups with conflicting filters. Make sure we
cover that when initially validating events.

Signed-off-by: Robin Murphy <robin.murphy@arm.com>
Signed-off-by: Will Deacon <will@kernel.org>
2019-08-27 19:37:04 +01:00
Robin Murphy
33e84ea433 perf/smmuv3: Validate group size
Ensure that a group will actually fit into the available counters.

Signed-off-by: Robin Murphy <robin.murphy@arm.com>
Signed-off-by: Will Deacon <will@kernel.org>
2019-08-27 19:37:04 +01:00
Vincenzo Frascino
92af2b6961 arm64: Relax Documentation/arm64/tagged-pointers.rst
On AArch64 the TCR_EL1.TBI0 bit is set by default, allowing userspace
(EL0) to perform memory accesses through 64-bit pointers with a non-zero
top byte. However, such pointers were not allowed at the user-kernel
syscall ABI boundary.

With the Tagged Address ABI patchset, it is now possible to pass tagged
pointers to the syscalls. Relax the requirements described in
tagged-pointers.rst to be compliant with the behaviours guaranteed by
the AArch64 Tagged Address ABI.

Cc: Will Deacon <will.deacon@arm.com>
Cc: Szabolcs Nagy <szabolcs.nagy@arm.com>
Cc: Kevin Brodsky <kevin.brodsky@arm.com>
Acked-by: Andrey Konovalov <andreyknvl@google.com>
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>
Signed-off-by: Will Deacon <will@kernel.org>
2019-08-27 18:16:20 +01:00
Will Deacon
5c062ef415 arm64: kvm: Replace hardcoded '1' with SYS_PAR_EL1_F
Now that we have a definition for the 'F' field of PAR_EL1, use that
instead of coding the immediate directly.

Acked-by: Marc Zyngier <maz@kernel.org>
Reviewed-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Will Deacon <will@kernel.org>
2019-08-27 17:38:41 +01:00
Will Deacon
42f91093b0 arm64: mm: Ignore spurious translation faults taken from the kernel
Thanks to address translation being performed out of order with respect to
loads and stores, it is possible for a CPU to take a translation fault when
accessing a page that was mapped by a different CPU.

For example, in the case that one CPU maps a page and then sets a flag to
tell another CPU:

	CPU 0
	-----

	MOV	X0, <valid pte>
	STR	X0, [Xptep]	// Store new PTE to page table
	DSB	ISHST
	ISB
	MOV	X1, #1
	STR	X1, [Xflag]	// Set the flag

	CPU 1
	-----

loop:	LDAR	X0, [Xflag]	// Poll flag with Acquire semantics
	CBZ	X0, loop
	LDR	X1, [X2]	// Translates using the new PTE

then the final load on CPU 1 can raise a translation fault because the
translation can be performed speculatively before the read of the flag and
marked as "faulting" by the CPU. This isn't quite as bad as it sounds
since, in reality, code such as:

	CPU 0				CPU 1
	-----				-----
	spin_lock(&lock);		spin_lock(&lock);
	*ptr = vmalloc(size);		if (*ptr)
	spin_unlock(&lock);			foo = **ptr;
					spin_unlock(&lock);

will not trigger the fault because there is an address dependency on CPU 1
which prevents the speculative translation. However, more exotic code where
the virtual address is known ahead of time, such as:

	CPU 0				CPU 1
	-----				-----
	spin_lock(&lock);		spin_lock(&lock);
	set_fixmap(0, paddr, prot);	if (mapped)
	mapped = true;				foo = *fix_to_virt(0);
	spin_unlock(&lock);		spin_unlock(&lock);

could fault. This can be avoided by any of:

	* Introducing broadcast TLB maintenance on the map path
	* Adding a DSB;ISB sequence after checking a flag which indicates
	  that a virtual address is now mapped
	* Handling the spurious fault

Given that we have never observed a problem due to this under Linux and
future revisions of the architecture are being tightened so that
translation table walks are effectively ordered in the same way as explicit
memory accesses, we no longer treat spurious kernel faults as fatal if an
AT instruction indicates that the access does not trigger a translation
fault.

Reviewed-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Will Deacon <will@kernel.org>
2019-08-27 17:38:36 +01:00
Will Deacon
e8620cff99 arm64: sysreg: Add some field definitions for PAR_EL1
PAR_EL1 is a mysterious creature, but sometimes it's necessary to read
it when translating addresses in situations where we cannot walk the
page table directly.

Add a couple of system register definitions for the fault indication
field ('F') and the fault status code ('FST').

Reviewed-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Will Deacon <will@kernel.org>
2019-08-27 17:38:33 +01:00
Will Deacon
eb6a4dcce3 arm64: mm: Add ISB instruction to set_pgd()
Commit 6a4cbd63c25a ("Revert "arm64: Remove unnecessary ISBs from
set_{pte,pmd,pud}"") reintroduced ISB instructions to some of our
page table setter functions in light of a recent clarification to the
Armv8 architecture. Although 'set_pgd()' isn't currently used to update
a live page table, add the ISB instruction there too for consistency
with the other macros and to provide some future-proofing if we use it
on live tables in the future.

Reported-by: Mark Rutland <mark.rutland@arm.com>
Reviewed-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Will Deacon <will@kernel.org>
2019-08-27 17:38:30 +01:00
Will Deacon
51696d346c arm64: tlb: Ensure we execute an ISB following walk cache invalidation
05f2d2f83b ("arm64: tlbflush: Introduce __flush_tlb_kernel_pgtable")
added a new TLB invalidation helper which is used when freeing
intermediate levels of page table used for kernel mappings, but is
missing the required ISB instruction after completion of the TLBI
instruction.

Add the missing barrier.

Cc: <stable@vger.kernel.org>
Fixes: 05f2d2f83b ("arm64: tlbflush: Introduce __flush_tlb_kernel_pgtable")
Reviewed-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Will Deacon <will@kernel.org>
2019-08-27 17:38:26 +01:00
Will Deacon
d0b7a302d5 Revert "arm64: Remove unnecessary ISBs from set_{pte,pmd,pud}"
This reverts commit 24fe1b0efa.

Commit 24fe1b0efa ("arm64: Remove unnecessary ISBs from
set_{pte,pmd,pud}") removed ISB instructions immediately following updates
to the page table, on the grounds that they are not required by the
architecture and a DSB alone is sufficient to ensure that subsequent data
accesses use the new translation:

  DDI0487E_a, B2-128:

  | ... no instruction that appears in program order after the DSB
  | instruction can alter any state of the system or perform any part of
  | its functionality until the DSB completes other than:
  |
  | * Being fetched from memory and decoded
  | * Reading the general-purpose, SIMD and floating-point,
  |   Special-purpose, or System registers that are directly or indirectly
  |   read without causing side-effects.

However, the same document also states the following:

  DDI0487E_a, B2-125:

  | DMB and DSB instructions affect reads and writes to the memory system
  | generated by Load/Store instructions and data or unified cache
  | maintenance instructions being executed by the PE. Instruction fetches
  | or accesses caused by a hardware translation table access are not
  | explicit accesses.

which appears to claim that the DSB alone is insufficient.  Unfortunately,
some CPU designers have followed the second clause above, whereas in Linux
we've been relying on the first. This means that our mapping sequence:

	MOV	X0, <valid pte>
	STR	X0, [Xptep]	// Store new PTE to page table
	DSB	ISHST
	LDR	X1, [X2]	// Translates using the new PTE

can actually raise a translation fault on the load instruction because the
translation can be performed speculatively before the page table update and
then marked as "faulting" by the CPU. For user PTEs, this is ok because we
can handle the spurious fault, but for kernel PTEs and intermediate table
entries this results in a panic().

Revert the offending commit to reintroduce the missing barriers.

Cc: <stable@vger.kernel.org>
Fixes: 24fe1b0efa ("arm64: Remove unnecessary ISBs from set_{pte,pmd,pud}")
Reviewed-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Will Deacon <will@kernel.org>
2019-08-27 17:38:15 +01:00
Will Deacon
ebef746543 arm64: smp: Treat unknown boot failures as being 'stuck in kernel'
When we fail to bring a secondary CPU online and it fails in an unknown
state, we should assume the worst and increment 'cpus_stuck_in_kernel'
so that things like kexec() are disabled.

Reviewed-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Will Deacon <will@kernel.org>
2019-08-27 17:37:05 +01:00
Will Deacon
5b1cfe3a0b arm64: smp: Don't enter kernel with NULL stack pointer or task struct
Although SMP bringup is inherently racy, we can significantly reduce
the window during which secondary CPUs can unexpectedly enter the
kernel by sanity checking the 'stack' and 'task' fields of the
'secondary_data' structure. If the booting CPU gave up waiting for us,
then they will have been cleared to NULL and we should spin in a WFE; WFI
loop instead.

Reviewed-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Will Deacon <will@kernel.org>
2019-08-27 17:37:02 +01:00
Will Deacon
0e1645557d arm64: smp: Increase secondary CPU boot timeout value
When many debug options are enabled simultaneously (e.g. PROVE_LOCKING,
KMEMLEAK, DEBUG_PAGE_ALLOC, KASAN etc), it is possible for us to timeout
when attempting to boot a secondary CPU and give up. Unfortunately, the
CPU will /eventually/ appear, and sit in the background happily stuck
in a recursive exception due to a NULL stack pointer.

Increase the timeout to 5s, which will of course be enough for anybody.

Reviewed-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Will Deacon <will@kernel.org>
2019-08-27 17:36:50 +01:00
Hsin-Yi Wang
dd753d961c fdt: Update CRC check for rng-seed
Commit 428826f535 ("fdt: add support for rng-seed") moves of_fdt_crc32
from early_init_dt_verify() to early_init_dt_scan() since
early_init_dt_scan_chosen() may modify fdt to erase rng-seed.

However, arm and some other arch won't call early_init_dt_scan(), they
call early_init_dt_verify() then early_init_dt_scan_nodes().

Restore of_fdt_crc32 to early_init_dt_verify() then update it in
early_init_dt_scan_chosen() if fdt if updated.

Fixes: 428826f535 ("fdt: add support for rng-seed")
Reported-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Hsin-Yi Wang <hsinyi@chromium.org>
Tested-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Will Deacon <will@kernel.org>
2019-08-27 12:27:07 +01:00
Hsin-Yi Wang
7f591fa7a6 arm64: kexec_file: add rng-seed support
Adding "rng-seed" to dtb. It's fine to add this property if original
fdt doesn't contain it. Since original seed will be wiped after
read, so use a default size 128 bytes here.

Signed-off-by: Hsin-Yi Wang <hsinyi@chromium.org>
Reviewed-by: Stephen Boyd <swboyd@chromium.org>
Signed-off-by: Will Deacon <will@kernel.org>
2019-08-23 16:40:14 +01:00
Hsin-Yi Wang
428826f535 fdt: add support for rng-seed
Introducing a chosen node, rng-seed, which is an entropy that can be
passed to kernel called very early to increase initial device
randomness. Bootloader should provide this entropy and the value is
read from /chosen/rng-seed in DT.

Obtain of_fdt_crc32 for CRC check after early_init_dt_scan_nodes(),
since early_init_dt_scan_chosen() would modify fdt to erase rng-seed.

Add a new interface add_bootloader_randomness() for rng-seed use case.
Depends on whether the seed is trustworthy, rng seed would be passed to
add_hwgenerator_randomness(). Otherwise it would be passed to
add_device_randomness(). Decision is controlled by kernel config
RANDOM_TRUST_BOOTLOADER.

Signed-off-by: Hsin-Yi Wang <hsinyi@chromium.org>
Reviewed-by: Stephen Boyd <swboyd@chromium.org>
Reviewed-by: Rob Herring <robh@kernel.org>
Reviewed-by: Theodore Ts'o <tytso@mit.edu> # drivers/char/random.c
Signed-off-by: Will Deacon <will@kernel.org>
2019-08-23 16:39:26 +01:00
Hsin-Yi Wang
e112b032a7 arm64: map FDT as RW for early_init_dt_scan()
Currently in arm64, FDT is mapped to RO before it's passed to
early_init_dt_scan(). However, there might be some codes
(eg. commit "fdt: add support for rng-seed") that need to modify FDT
during init. Map FDT to RO after early fixups are done.

Signed-off-by: Hsin-Yi Wang <hsinyi@chromium.org>
Reviewed-by: Stephen Boyd <swboyd@chromium.org>
Reviewed-by: Mike Rapoport <rppt@linux.ibm.com>
Signed-off-by: Will Deacon <will@kernel.org>
2019-08-23 16:39:16 +01:00
Vincenzo Frascino
1243cb6a67 arm64: Add tagged-address-abi.rst to index.rst
Documentation/arm64/tagged-address-abi.rst introduces the
relaxation of the syscall ABI that allows userspace to pass
certain tagged pointers to kernel syscalls.

Add the document to index.rst for a correct generation of the
table of content.

Cc: Will Deacon <will@kernel.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Signed-off-by: Will Deacon <will@kernel.org>
2019-08-22 18:22:57 +01:00
Vincenzo Frascino
e1b832503e arm64: Define Documentation/arm64/tagged-address-abi.rst
On AArch64 the TCR_EL1.TBI0 bit is set by default, allowing userspace
(EL0) to perform memory accesses through 64-bit pointers with a non-zero
top byte. Introduce the document describing the relaxation of the
syscall ABI that allows userspace to pass certain tagged pointers to
kernel syscalls.

Cc: Will Deacon <will.deacon@arm.com>
Cc: Szabolcs Nagy <szabolcs.nagy@arm.com>
Acked-by: Kevin Brodsky <kevin.brodsky@arm.com>
Acked-by: Andrey Konovalov <andreyknvl@google.com>
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>
Signed-off-by: Will Deacon <will@kernel.org>
2019-08-22 12:32:26 +01:00
Masahiro Yamada
6bfa3134bd arm64: add arch/arm64/Kbuild
Use the standard obj-y form to specify the sub-directories under
arch/arm64/. No functional change intended.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Will Deacon <will@kernel.org>
2019-08-21 18:47:15 +01:00
James Morse
2671828c3f arm64: entry: Move ct_user_exit before any other exception
When taking an SError or Debug exception from EL0, we run the C
handler for these exceptions before updating the context tracking
code and unmasking lower priority interrupts.

When booting with nohz_full lockdep tells us we got this wrong:
| =============================
| WARNING: suspicious RCU usage
| 5.3.0-rc2-00010-gb4b5e9dcb11b-dirty #11271 Not tainted
| -----------------------------
| include/linux/rcupdate.h:643 rcu_read_unlock() used illegally wh!
|
| other info that might help us debug this:
|
|
| RCU used illegally from idle CPU!
| rcu_scheduler_active = 2, debug_locks = 1
| RCU used illegally from extended quiescent state!
| 1 lock held by a.out/432:
|  #0: 00000000c7a79515 (rcu_read_lock){....}, at: brk_handler+0x00
|
| stack backtrace:
| CPU: 1 PID: 432 Comm: a.out Not tainted 5.3.0-rc2-00010-gb4b5e9d1
| Hardware name: ARM LTD ARM Juno Development Platform/ARM Juno De8
| Call trace:
|  dump_backtrace+0x0/0x140
|  show_stack+0x14/0x20
|  dump_stack+0xbc/0x104
|  lockdep_rcu_suspicious+0xf8/0x108
|  brk_handler+0x164/0x1b0
|  do_debug_exception+0x11c/0x278
|  el0_dbg+0x14/0x20

Moving the ct_user_exit calls to be before do_debug_exception() means
they are also before trace_hardirqs_off() has been updated. Add a new
ct_user_exit_irqoff macro to avoid the context-tracking code using
irqsave/restore before we've updated trace_hardirqs_off(). To be
consistent, do this everywhere.

The C helper is called enter_from_user_mode() to match x86 in the hope
we can merge them into kernel/context_tracking.c later.

Cc: Masami Hiramatsu <mhiramat@kernel.org>
Fixes: 6c81fe7925 ("arm64: enable context tracking")
Signed-off-by: James Morse <james.morse@arm.com>
Signed-off-by: Will Deacon <will@kernel.org>
2019-08-21 18:45:52 +01:00
Catalin Marinas
413235fced arm64: Change the tagged_addr sysctl control semantics to only prevent the opt-in
First rename the sysctl control to abi.tagged_addr_disabled and make it
default off (zero). When abi.tagged_addr_disabled == 1, only block the
enabling of the TBI ABI via prctl(PR_SET_TAGGED_ADDR_CTRL, PR_TAGGED_ADDR_ENABLE).
Getting the status of the ABI or disabling it is still allowed.

Acked-by: Andrey Konovalov <andreyknvl@google.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Will Deacon <will@kernel.org>
2019-08-20 18:18:10 +01:00
Catalin Marinas
3e91ec89f5 arm64: Tighten the PR_{SET, GET}_TAGGED_ADDR_CTRL prctl() unused arguments
Require that arg{3,4,5} of the PR_{SET,GET}_TAGGED_ADDR_CTRL prctl and
arg2 of the PR_GET_TAGGED_ADDR_CTRL prctl() are zero rather than ignored
for future extensions.

Acked-by: Andrey Konovalov <andreyknvl@google.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Will Deacon <will@kernel.org>
2019-08-20 18:17:55 +01:00
Raphael Gault
d91cc2f46a arm64: perf_event: Add missing header needed for smp_processor_id()
In perf_event.c we use smp_processor_id(), but we haven't included
<linux/smp.h> where it is defined, and rely on this being pulled in
via a transitive include. Let's make this more robust by including
<linux.smp.h> explicitly.

Acked-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Raphael Gault <raphael.gault@arm.com>
Signed-off-by: Will Deacon <will@kernel.org>
2019-08-20 17:10:05 +01:00
Will Deacon
2d12294248 Revert "init/Kconfig: Fix infinite Kconfig recursion on PPC"
This reverts commit 71c67a31f0.

Commit 117acf5c29 ("powerpc/Makefile: Always pass --synthetic to nm if
supported") removed the only conditional definition of $(NM), so we can
revert our temporary bodge to avoid Kconfig recursion and go back to
passing $(NM) through to the 'tools-support-relr.sh' when detecting
support for RELR relocations.

Signed-off-by: Will Deacon <will@kernel.org>
2019-08-20 10:11:54 +01:00
Michael Ellerman
117acf5c29 powerpc/Makefile: Always pass --synthetic to nm if supported
Back in 2004 we added logic to arch/ppc64/Makefile to pass
the --synthetic option to nm, if it was supported by nm.

Then in 2005 when arch/ppc64 and arch/ppc were merged, the logic to
add --synthetic was moved inside an #ifdef CONFIG_PPC64 block within
arch/powerpc/Makefile, and has remained there since.

That was fine, though crufty, until recently when a change to
init/Kconfig added a config time check that uses $(NM). On powerpc
that leads to an infinite loop because Kconfig uses $(NM) to calculate
some values, then the powerpc Makefile changes $(NM), which Kconfig
notices and restarts.

The original commit that added --synthetic simply said:
  On new toolchains we need to use nm --synthetic or we miss code
  symbols.

And the nm man page says that the --synthetic option causes nm to:
  Include synthetic symbols in the output. These are special symbols
  created by the linker for various purposes.

So it seems safe to always pass --synthetic if nm supports it, ie. on
32-bit and 64-bit, it just means 32-bit kernels might have more
symbols reported (and in practice I see no extra symbols). Making it
unconditional avoids the #ifdef CONFIG_PPC64, which in turn avoids the
infinite loop.

Debugged-by: Peter Collingbourne <pcc@google.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Will Deacon <will@kernel.org>
2019-08-20 10:01:18 +01:00
Andrey Konovalov
74585fcb7b selftests, arm64: fix uninitialized symbol in tags_test.c
Fix tagged_ptr not being initialized when TBI is not enabled.

Link: https://www.spinics.net/lists/linux-kselftest/msg09446.html
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Signed-off-by: Will Deacon <will@kernel.org>
2019-08-19 16:25:32 +01:00
Mark Rutland
34b5560db4 kasan/arm64: fix CONFIG_KASAN_SW_TAGS && KASAN_INLINE
The generic Makefile.kasan propagates CONFIG_KASAN_SHADOW_OFFSET into
KASAN_SHADOW_OFFSET, but only does so for CONFIG_KASAN_GENERIC.

Since commit:

  6bd1d0be0e ("arm64: kasan: Switch to using KASAN_SHADOW_OFFSET")

... arm64 defines CONFIG_KASAN_SHADOW_OFFSET in Kconfig rather than
defining KASAN_SHADOW_OFFSET in a Makefile. Thus, if
CONFIG_KASAN_SW_TAGS && KASAN_INLINE are selected, we get build time
splats due to KASAN_SHADOW_OFFSET not being set:

| [mark@lakrids:~/src/linux]% usellvm 8.0.1 usekorg 8.1.0  make ARCH=arm64 CROSS_COMPILE=aarch64-linux- CC=clang
| scripts/kconfig/conf  --syncconfig Kconfig
|   CC      scripts/mod/empty.o
| clang (LLVM option parsing): for the -hwasan-mapping-offset option: '' value invalid for uint argument!
| scripts/Makefile.build:273: recipe for target 'scripts/mod/empty.o' failed
| make[1]: *** [scripts/mod/empty.o] Error 1
| Makefile:1123: recipe for target 'prepare0' failed
| make: *** [prepare0] Error 2

Let's fix this by always propagating CONFIG_KASAN_SHADOW_OFFSET into
KASAN_SHADOW_OFFSET if CONFIG_KASAN is selected, moving the existing
common definition of +CFLAGS_KASAN_NOSANITIZE to the top of
Makefile.kasan.

Cc: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Acked-by: Andrey Ryabinin <aryabinin@virtuozzo.com>
Tested-by Steve Capper <steve.capper@arm.com>
Signed-off-by: Will Deacon <will@kernel.org>
2019-08-15 13:24:04 +01:00
Christoph Hellwig
d225bb8d8a arm64: unexport set_memory_x and set_memory_nx
No module currently messed with clearing or setting the execute
permission of kernel memory, and none really should.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Will Deacon <will@kernel.org>
2019-08-15 12:58:26 +01:00
Sudeep Holla
d55c5f28af arm64: smp: disable hotplug on trusted OS resident CPU
The trusted OS may reject CPU_OFF calls to its resident CPU, so we must
avoid issuing those. We never migrate a Trusted OS and we already take
care to prevent CPU_OFF PSCI call. However, this is not reflected
explicitly to the userspace. Any user can attempt to hotplug trusted OS
resident CPU. The entire motion of going through the various state
transitions in the CPU hotplug state machine gets executed and the
PSCI layer finally refuses to make CPU_OFF call.

This results is unnecessary unwinding of CPU hotplug state machine in
the kernel. Instead we can mark the trusted OS resident CPU as not
available for hotplug, so that the user attempt or request to do the
same will get immediately rejected.

Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
Signed-off-by: Will Deacon <will@kernel.org>
2019-08-15 11:12:03 +01:00
Kees Cook
90776dd1c4 arm64/efi: Move variable assignments after SECTIONS
It seems that LLVM's linker does not correctly handle variable assignments
involving section positions that are updated during the SECTIONS
parsing. Commit aa69fb62be ("arm64/efi: Mark __efistub_stext_offset as
an absolute symbol explicitly") ran into this too, but found a different
workaround.

However, this was not enough, as other variables were also miscalculated
which manifested as boot failures under UEFI where __efistub__end was
not taking the correct _end value (they should be the same):

$ ld.lld -EL -maarch64elf --no-undefined -X -shared \
	-Bsymbolic -z notext -z norelro --no-apply-dynamic-relocs \
	-o vmlinux.lld -T poc.lds --whole-archive vmlinux.o && \
  readelf -Ws vmlinux.lld | egrep '\b(__efistub_|)_end\b'
368272: ffff000002218000     0 NOTYPE  LOCAL  HIDDEN    38 __efistub__end
368322: ffff000012318000     0 NOTYPE  GLOBAL DEFAULT   38 _end

$ aarch64-linux-gnu-ld.bfd -EL -maarch64elf --no-undefined -X -shared \
	-Bsymbolic -z notext -z norelro --no-apply-dynamic-relocs \
	-o vmlinux.bfd -T poc.lds --whole-archive vmlinux.o && \
  readelf -Ws vmlinux.bfd | egrep '\b(__efistub_|)_end\b'
338124: ffff000012318000     0 NOTYPE  LOCAL  DEFAULT  ABS __efistub__end
383812: ffff000012318000     0 NOTYPE  GLOBAL DEFAULT 15325 _end

To work around this, all of the __efistub_-prefixed variable assignments
need to be moved after the linker script's SECTIONS entry. As it turns
out, this also solves the problem fixed in commit aa69fb62be, so those
changes are reverted here.

Link: https://github.com/ClangBuiltLinux/linux/issues/634
Link: https://bugs.llvm.org/show_bug.cgi?id=42990
Acked-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Will Deacon <will@kernel.org>
2019-08-14 17:18:15 +01:00
Mark Brown
38d1666760 arm64: Clarify when cpu_enable() is called
Strengthen the wording in the documentation for cpu_enable() to make it
more obvious to readers not already familiar with the code when the core
will call this callback and that this is intentional.

Signed-off-by: Mark Brown <broonie@kernel.org>
Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com>
[will: minor tweak to emphasis in the comment]
Signed-off-by: Will Deacon <will@kernel.org>
2019-08-14 17:12:53 +01:00
Mark Rutland
77ad4ce693 arm64: memory: rename VA_START to PAGE_END
Prior to commit:

  14c127c957 ("arm64: mm: Flip kernel VA space")

... VA_START described the start of the TTBR1 address space for a given
VA size described by VA_BITS, where all kernel mappings began.

Since that commit, VA_START described a portion midway through the
address space, where the linear map ends and other kernel mappings
begin.

To avoid confusion, let's rename VA_START to PAGE_END, making it clear
that it's not the start of the TTBR1 address space and implying that
it's related to PAGE_OFFSET. Comments and other mnemonics are updated
accordingly, along with a typo fix in the decription of VMEMMAP_SIZE.

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

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Tested-by: Steve Capper <steve.capper@arm.com>
Reviewed-by: Steve Capper <steve.capper@arm.com>
Signed-off-by: Will Deacon <will@kernel.org>
2019-08-14 17:06:58 +01:00
Mark Rutland
233947ef16 arm64: memory: fix flipped VA space fallout
VA_START used to be the start of the TTBR1 address space, but now it's a
point midway though. In a couple of places we still use VA_START to get
the start of the TTBR1 address space, so let's fix these up to use
PAGE_OFFSET instead.

Fixes: 14c127c957 ("arm64: mm: Flip kernel VA space")
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Tested-by: Steve Capper <steve.capper@arm.com>
Reviewed-by: Steve Capper <steve.capper@arm.com>
Signed-off-by: Will Deacon <will@kernel.org>
2019-08-14 17:05:11 +01:00
Will Deacon
d0b3c32ed9 arm64: memory: Cosmetic cleanups
Cleanup memory.h so that the indentation is consistent, remove pointless
line-wrapping and use consistent parameter names for different versions
of the same macro.

Reviewed-by: Steve Capper <steve.capper@arm.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Reviewed-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Will Deacon <will@kernel.org>
2019-08-14 13:09:45 +01:00
Will Deacon
68933aa973 arm64: memory: Add comments to end of non-trivial #ifdef blocks
Commenting the #endif of a multi-statement #ifdef block with the
condition which guards it is useful and can save having to scroll back
through the file to figure out which set of Kconfig options apply to
a particular piece of code.

Reviewed-by: Steve Capper <steve.capper@arm.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Reviewed-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Will Deacon <will@kernel.org>
2019-08-14 13:09:24 +01:00
Will Deacon
6bbd497f02 arm64: memory: Implement __tag_set() as common function
There's no need for __tag_set() to be a complicated macro when
CONFIG_KASAN_SW_TAGS=y and a simple static inline otherwise. Rewrite
the thing as a common static inline function.

Tested-by: Steve Capper <steve.capper@arm.com>
Reviewed-by: Steve Capper <steve.capper@arm.com>
Tested-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Reviewed-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Will Deacon <will@kernel.org>
2019-08-14 13:08:44 +01:00
Will Deacon
a5ac40f53b arm64: memory: Simplify _VA_START and _PAGE_OFFSET definitions
Rather than subtracting from -1 and then adding 1, we can simply
subtract from 0.

Tested-by: Steve Capper <steve.capper@arm.com>
Reviewed-by: Steve Capper <steve.capper@arm.com>
Tested-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Will Deacon <will@kernel.org>
2019-08-14 13:08:40 +01:00
Will Deacon
9ba33dcc6b arm64: memory: Simplify virt_to_page() implementation
Build virt_to_page() on top of virt_to_pfn() so we can avoid the need
for explicit shifting.

Tested-by: Steve Capper <steve.capper@arm.com>
Reviewed-by: Steve Capper <steve.capper@arm.com>
Tested-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Reviewed-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Will Deacon <will@kernel.org>
2019-08-14 13:07:49 +01:00
Will Deacon
96628f0fb1 arm64: memory: Rewrite default page_to_virt()/virt_to_page()
The default implementations of page_to_virt() and virt_to_page() are
fairly confusing to read and the former evaluates its 'page' parameter
twice in the macro

Rewrite them so that the computation is expressed as 'base + index' in
both cases and the parameter is always evaluated exactly once.

Tested-by: Steve Capper <steve.capper@arm.com>
Reviewed-by: Steve Capper <steve.capper@arm.com>
Tested-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Will Deacon <will@kernel.org>
2019-08-14 13:05:35 +01:00
Will Deacon
577c2b3528 arm64: memory: Ensure address tag is masked in conversion macros
When converting a linear virtual address to a physical address, pfn or
struct page *, we must make sure that the tag bits are masked before the
calculation otherwise we end up with corrupt pointers when running with
CONFIG_KASAN_SW_TAGS=y:

  | Unable to handle kernel paging request at virtual address 0037fe0007580d08
  | [0037fe0007580d08] address between user and kernel address ranges

Mask out the tag in __virt_to_phys_nodebug() and virt_to_page().

Reported-by: Qian Cai <cai@lca.pw>
Reported-by: Geert Uytterhoeven <geert@linux-m68k.org>
Tested-by: Steve Capper <steve.capper@arm.com>
Reviewed-by: Steve Capper <steve.capper@arm.com>
Tested-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Reviewed-by: Mark Rutland <mark.rutland@arm.com>
Fixes: 9cb1c5ddd2 ("arm64: mm: Remove bit-masking optimisations for PAGE_OFFSET and VMEMMAP_START")
Signed-off-by: Will Deacon <will@kernel.org>
2019-08-14 13:04:46 +01:00
Will Deacon
68dd8ef321 arm64: memory: Fix virt_addr_valid() using __is_lm_address()
virt_addr_valid() is intended to test whether or not the passed address
is a valid linear map address. Unfortunately, it relies on
_virt_addr_is_linear() which is broken because it assumes the linear
map is at the top of the address space, which it no longer is.

Reimplement virt_addr_valid() using __is_lm_address() and remove
_virt_addr_is_linear() entirely. At the same time, ensure we evaluate
the macro parameter only once and move it within the __ASSEMBLY__ block.

Reported-by: Qian Cai <cai@lca.pw>
Reported-by: Geert Uytterhoeven <geert@linux-m68k.org>
Tested-by: Steve Capper <steve.capper@arm.com>
Reviewed-by: Steve Capper <steve.capper@arm.com>
Tested-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Reviewed-by: Mark Rutland <mark.rutland@arm.com>
Fixes: 14c127c957 ("arm64: mm: Flip kernel VA space")
Signed-off-by: Will Deacon <will@kernel.org>
2019-08-14 13:00:57 +01:00
Will Deacon
d06fa5a118 Merge tag 'common/for-v5.4-rc1/cpu-topology' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux into for-next/cpu-topology
Pull in generic CPU topology changes from Paul Walmsley (RISC-V).

* tag 'common/for-v5.4-rc1/cpu-topology' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux:
  MAINTAINERS: Add an entry for generic architecture topology
  base: arch_topology: update Kconfig help description
  RISC-V: Parse cpu topology during boot.
  arm: Use common cpu_topology structure and functions.
  cpu-topology: Move cpu topology code to common code.
  dt-binding: cpu-topology: Move cpu-map to a common binding.
  Documentation: DT: arm: add support for sockets defining package boundaries
2019-08-14 10:07:00 +01:00
Mark Rutland
37143dcc44 arm64: constify sys64_hook instances
All instances of struct sys64_hook contain compile-time constant data,
and are never inentionally modified, so let's make them all const.

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Will Deacon <will@kernel.org>
2019-08-13 18:32:17 +01:00
Mark Rutland
0da23df2ff arm64: constify aarch64_insn_encoding_class[]
The aarch64_insn_encoding_class[] array contains compile-time constant
data, and is never intentionally modified, so let's mark it as const.

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Will Deacon <will@kernel.org>
2019-08-13 18:32:17 +01:00
Mark Rutland
0bf136a8cf arm64: constify icache_policy_str[]
The icache_policy_str[] array contains compile-time constant data, and
is never intentionally modified, so let's mark it as const.

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Will Deacon <will@kernel.org>
2019-08-13 18:32:17 +01:00