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825,598 commits

Author SHA1 Message Date
Will Deacon
50abbe1962 Merge branch 'for-next/mitigations' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux into for-next/core 2019-05-01 15:34:56 +01:00
Will Deacon
9431ac2bf6 Merge branch 'for-next/futex' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux into for-next/core 2019-05-01 15:34:17 +01:00
Josh Poimboeuf
4ad499c942 Documentation: Add ARM64 to kernel-parameters.rst
Add ARM64 to the legend of architectures.  It's already used in several
places in kernel-parameters.txt.

Suggested-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
2019-05-01 14:48:08 +01:00
Josh Poimboeuf
a111b7c0f2 arm64/speculation: Support 'mitigations=' cmdline option
Configure arm64 runtime CPU speculation bug mitigations in accordance
with the 'mitigations=' cmdline option.  This affects Meltdown, Spectre
v2, and Speculative Store Bypass.

The default behavior is unchanged.

Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
[will: reorder checks so KASLR implies KPTI and SSBS is affected by cmdline]
Signed-off-by: Will Deacon <will.deacon@arm.com>
2019-05-01 14:48:07 +01:00
Will Deacon
eb337cdfcd arm64: ssbs: Don't treat CPUs with SSBS as unaffected by SSB
SSBS provides a relatively cheap mitigation for SSB, but it is still a
mitigation and its presence does not indicate that the CPU is unaffected
by the vulnerability.

Tweak the mitigation logic so that we report the correct string in sysfs.

Signed-off-by: Will Deacon <will.deacon@arm.com>
2019-05-01 14:48:06 +01:00
Mian Yousaf Kaukab
61ae1321f0 arm64: enable generic CPU vulnerabilites support
Enable CPU vulnerabilty show functions for spectre_v1, spectre_v2,
meltdown and store-bypass.

Signed-off-by: Mian Yousaf Kaukab <ykaukab@suse.de>
Signed-off-by: Jeremy Linton <jeremy.linton@arm.com>
Reviewed-by: Andre Przywara <andre.przywara@arm.com>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Tested-by: Stefan Wahren <stefan.wahren@i2se.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
2019-05-01 14:48:06 +01:00
Jeremy Linton
526e065dbc arm64: add sysfs vulnerability show for speculative store bypass
Return status based on ssbd_state and __ssb_safe. If the
mitigation is disabled, or the firmware isn't responding then
return the expected machine state based on a whitelist of known
good cores.

Given a heterogeneous machine, the overall machine vulnerability
defaults to safe but is reset to unsafe when we miss the whitelist
and the firmware doesn't explicitly tell us the core is safe.
In order to make that work we delay transitioning to vulnerable
until we know the firmware isn't responding to avoid a case
where we miss the whitelist, but the firmware goes ahead and
reports the core is not vulnerable. If all the cores in the
machine have SSBS, then __ssb_safe will remain true.

Tested-by: Stefan Wahren <stefan.wahren@i2se.com>
Signed-off-by: Jeremy Linton <jeremy.linton@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
2019-05-01 14:47:55 +01:00
Arun KS
61cf61d81e arm64: Fix size of __early_cpu_boot_status
__early_cpu_boot_status is of type long. Use quad
assembler directive to allocate proper size.

Acked-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Arun KS <arunks@codeaurora.org>
Signed-off-by: Will Deacon <will.deacon@arm.com>
2019-05-01 14:39:26 +01:00
Qian Cai
5fbbeedb9a arm64: mm: Remove pte_unmap_nested()
As of commit ece0e2b640 ("mm: remove pte_*map_nested()"),
pte_unmap_nested() is no longer used and can be removed from the arm64
code.

Signed-off-by: Qian Cai <cai@lca.pw>
[will: also remove pte_offset_map_nested()]
Signed-off-by: Will Deacon <will.deacon@arm.com>
2019-04-30 12:02:20 +01:00
Qian Cai
74dd022f9e arm64: Fix compiler warning from pte_unmap() with -Wunused-but-set-variable
When building with -Wunused-but-set-variable, the compiler shouts about
a number of pte_unmap() users, since this expands to an empty macro on
arm64:

  | mm/gup.c: In function 'gup_pte_range':
  | mm/gup.c:1727:16: warning: variable 'ptem' set but not used
  | [-Wunused-but-set-variable]
  | mm/gup.c: At top level:
  | mm/memory.c: In function 'copy_pte_range':
  | mm/memory.c:821:24: warning: variable 'orig_dst_pte' set but not used
  | [-Wunused-but-set-variable]
  | mm/memory.c:821:9: warning: variable 'orig_src_pte' set but not used
  | [-Wunused-but-set-variable]
  | mm/swap_state.c: In function 'swap_ra_info':
  | mm/swap_state.c:641:15: warning: variable 'orig_pte' set but not used
  | [-Wunused-but-set-variable]
  | mm/madvise.c: In function 'madvise_free_pte_range':
  | mm/madvise.c:318:9: warning: variable 'orig_pte' set but not used
  | [-Wunused-but-set-variable]

Rewrite pte_unmap() as a static inline function, which silences the
warnings.

Signed-off-by: Qian Cai <cai@lca.pw>
Signed-off-by: Will Deacon <will.deacon@arm.com>
2019-04-30 11:58:28 +01:00
Vincenzo Frascino
359db57c34 arm64: compat: Reduce address limit for 64K pages
With the introduction of the config option that allows to enable kuser
helpers, it is now possible to reduce TASK_SIZE_32 when these are
disabled and 64K pages are enabled. This extends the compliance with
the section 6.5.8 of the C standard (C99).

Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Reported-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
2019-04-30 11:04:50 +01:00
Will Deacon
75a19a0202 arm64: arch_timer: Ensure counter register reads occur with seqlock held
When executing clock_gettime(), either in the vDSO or via a system call,
we need to ensure that the read of the counter register occurs within
the seqlock reader critical section. This ensures that updates to the
clocksource parameters (e.g. the multiplier) are consistent with the
counter value and therefore avoids the situation where time appears to
go backwards across multiple reads.

Extend the vDSO logic so that the seqlock critical section covers the
read of the counter register as well as accesses to the data page. Since
reads of the counter system registers are not ordered by memory barrier
instructions, introduce dependency ordering from the counter read to a
subsequent memory access so that the seqlock memory barriers apply to
the counter access in both the vDSO and the system call paths.

Cc: <stable@vger.kernel.org>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Tested-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Link: https://lore.kernel.org/linux-arm-kernel/alpine.DEB.2.21.1902081950260.1662@nanos.tec.linutronix.de/
Reported-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Will Deacon <will.deacon@arm.com>
2019-04-30 11:04:23 +01:00
Xiongfeng Wang
2f1d4e24d9 firmware: arm_sdei: Prohibit probing in '_sdei_handler'
Functions called in '_sdei_handler' are needed to be marked as
'nokprobe'. Because these functions are called in NMI context and
neither the arch-code's debug infrastructure nor kprobes core supports
this.

Signed-off-by: Xiongfeng Wang <wangxiongfeng2@huawei.com>
Reviewed-by: James Morse <james.morse@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
2019-04-29 16:50:48 +01:00
Boyang Zhou
f08cae2f28 arm64: mmap: Ensure file offset is treated as unsigned
The file offset argument to the arm64 sys_mmap() implementation is
scaled from bytes to pages by shifting right by PAGE_SHIFT.
Unfortunately, the offset is passed in as a signed 'off_t' type and
therefore large offsets (i.e. with the top bit set) are incorrectly
sign-extended by the shift. This has been observed to cause false mmap()
failures when mapping GPU doorbells on an arm64 server part.

Change the type of the file offset argument to sys_mmap() from 'off_t'
to 'unsigned long' so that the shifting scales the value as expected.

Cc: <stable@vger.kernel.org>
Signed-off-by: Boyang Zhou <zhouby_cn@126.com>
[will: rewrote commit message]
Signed-off-by: Will Deacon <will.deacon@arm.com>
2019-04-29 15:27:41 +01:00
Will Deacon
bc15cf701f arm64: Kconfig: Tidy up errata workaround help text
The nature of silicon errata means that the Kconfig help text for our
various software workarounds has been written by many different people.
Along the way, we've accumulated typos and inconsistencies which make
the options needlessly difficult to read.

Fix up minor issues with the help text.

Signed-off-by: Will Deacon <will.deacon@arm.com>
2019-04-29 14:21:11 +01:00
Jeremy Linton
d42281b6e4 arm64: Always enable ssb vulnerability detection
Ensure we are always able to detect whether or not the CPU is affected
by SSB, so that we can later advertise this to userspace.

Signed-off-by: Jeremy Linton <jeremy.linton@arm.com>
Reviewed-by: Andre Przywara <andre.przywara@arm.com>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Tested-by: Stefan Wahren <stefan.wahren@i2se.com>
[will: Use IS_ENABLED instead of #ifdef]
Signed-off-by: Will Deacon <will.deacon@arm.com>
2019-04-26 16:32:45 +01:00
Jeremy Linton
d2532e27b5 arm64: add sysfs vulnerability show for spectre-v2
Track whether all the cores in the machine are vulnerable to Spectre-v2,
and whether all the vulnerable cores have been mitigated. We then expose
this information to userspace via sysfs.

Signed-off-by: Jeremy Linton <jeremy.linton@arm.com>
Reviewed-by: Andre Przywara <andre.przywara@arm.com>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Tested-by: Stefan Wahren <stefan.wahren@i2se.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
2019-04-26 16:31:36 +01:00
Jeremy Linton
8c1e3d2bb4 arm64: Always enable spectre-v2 vulnerability detection
Ensure we are always able to detect whether or not the CPU is affected
by Spectre-v2, so that we can later advertise this to userspace.

Signed-off-by: Jeremy Linton <jeremy.linton@arm.com>
Reviewed-by: Andre Przywara <andre.przywara@arm.com>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Tested-by: Stefan Wahren <stefan.wahren@i2se.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
2019-04-26 16:30:18 +01:00
Marc Zyngier
517953c2c4 arm64: Use firmware to detect CPUs that are not affected by Spectre-v2
The SMCCC ARCH_WORKAROUND_1 service can indicate that although the
firmware knows about the Spectre-v2 mitigation, this particular
CPU is not vulnerable, and it is thus not necessary to call
the firmware on this CPU.

Let's use this information to our benefit.

Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Jeremy Linton <jeremy.linton@arm.com>
Reviewed-by: Andre Przywara <andre.przywara@arm.com>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Tested-by: Stefan Wahren <stefan.wahren@i2se.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
2019-04-26 16:30:11 +01:00
Marc Zyngier
73f3816609 arm64: Advertise mitigation of Spectre-v2, or lack thereof
We currently have a list of CPUs affected by Spectre-v2, for which
we check that the firmware implements ARCH_WORKAROUND_1. It turns
out that not all firmwares do implement the required mitigation,
and that we fail to let the user know about it.

Instead, let's slightly revamp our checks, and rely on a whitelist
of cores that are known to be non-vulnerable, and let the user know
the status of the mitigation in the kernel log.

Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Jeremy Linton <jeremy.linton@arm.com>
Reviewed-by: Andre Przywara <andre.przywara@arm.com>
Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Tested-by: Stefan Wahren <stefan.wahren@i2se.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
2019-04-26 16:29:15 +01:00
Jeremy Linton
1b3ccf4be0 arm64: add sysfs vulnerability show for meltdown
We implement page table isolation as a mitigation for meltdown.
Report this to userspace via sysfs.

Signed-off-by: Jeremy Linton <jeremy.linton@arm.com>
Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Reviewed-by: Andre Przywara <andre.przywara@arm.com>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Tested-by: Stefan Wahren <stefan.wahren@i2se.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
2019-04-26 16:28:12 +01:00
Mian Yousaf Kaukab
3891ebccac arm64: Add sysfs vulnerability show for spectre-v1
spectre-v1 has been mitigated and the mitigation is always active.
Report this to userspace via sysfs

Signed-off-by: Mian Yousaf Kaukab <ykaukab@suse.de>
Signed-off-by: Jeremy Linton <jeremy.linton@arm.com>
Reviewed-by: Andre Przywara <andre.przywara@arm.com>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Tested-by: Stefan Wahren <stefan.wahren@i2se.com>
Acked-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
2019-04-26 16:27:10 +01:00
Jeremy Linton
e5ce5e7267 arm64: Provide a command line to disable spectre_v2 mitigation
There are various reasons, such as benchmarking, to disable spectrev2
mitigation on a machine. Provide a command-line option to do so.

Signed-off-by: Jeremy Linton <jeremy.linton@arm.com>
Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Reviewed-by: Andre Przywara <andre.przywara@arm.com>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Tested-by: Stefan Wahren <stefan.wahren@i2se.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: linux-doc@vger.kernel.org
Signed-off-by: Will Deacon <will.deacon@arm.com>
2019-04-26 16:26:42 +01:00
Will Deacon
4275035197 futex: Update comments and docs about return values of arch futex code
The architecture implementations of 'arch_futex_atomic_op_inuser()' and
'futex_atomic_cmpxchg_inatomic()' are permitted to return only -EFAULT,
-EAGAIN or -ENOSYS in the case of failure.

Update the comments in the asm-generic/ implementation and also a stray
reference in the robust futex documentation.

Signed-off-by: Will Deacon <will.deacon@arm.com>
2019-04-26 13:57:55 +01:00
Will Deacon
8e4e0ac02b arm64: futex: Avoid copying out uninitialised stack in failed cmpxchg()
Returning an error code from futex_atomic_cmpxchg_inatomic() indicates
that the caller should not make any use of *uval, and should instead act
upon on the value of the error code. Although this is implemented
correctly in our futex code, we needlessly copy uninitialised stack to
*uval in the error case, which can easily be avoided.

Signed-off-by: Will Deacon <will.deacon@arm.com>
2019-04-26 13:57:49 +01:00
Will Deacon
03110a5cb2 arm64: futex: Bound number of LDXR/STXR loops in FUTEX_WAKE_OP
Our futex implementation makes use of LDXR/STXR loops to perform atomic
updates to user memory from atomic context. This can lead to latency
problems if we end up spinning around the LL/SC sequence at the expense
of doing something useful.

Rework our futex atomic operations so that we return -EAGAIN if we fail
to update the futex word after 128 attempts. The core futex code will
reschedule if necessary and we'll try again later.

Cc: <stable@kernel.org>
Fixes: 6170a97460 ("arm64: Atomic operations")
Signed-off-by: Will Deacon <will.deacon@arm.com>
2019-04-26 13:57:43 +01:00
Will Deacon
6b4f4bc9cb locking/futex: Allow low-level atomic operations to return -EAGAIN
Some futex() operations, including FUTEX_WAKE_OP, require the kernel to
perform an atomic read-modify-write of the futex word via the userspace
mapping. These operations are implemented by each architecture in
arch_futex_atomic_op_inuser() and futex_atomic_cmpxchg_inatomic(), which
are called in atomic context with the relevant hash bucket locks held.

Although these routines may return -EFAULT in response to a page fault
generated when accessing userspace, they are expected to succeed (i.e.
return 0) in all other cases. This poses a problem for architectures
that do not provide bounded forward progress guarantees or fairness of
contended atomic operations and can lead to starvation in some cases.

In these problematic scenarios, we must return back to the core futex
code so that we can drop the hash bucket locks and reschedule if
necessary, much like we do in the case of a page fault.

Allow architectures to return -EAGAIN from their implementations of
arch_futex_atomic_op_inuser() and futex_atomic_cmpxchg_inatomic(), which
will cause the core futex code to reschedule if necessary and return
back to the architecture code later on.

Cc: <stable@kernel.org>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Will Deacon <will.deacon@arm.com>
2019-04-26 13:57:31 +01:00
Will Deacon
84ff7a09c3 arm64: futex: Fix FUTEX_WAKE_OP atomic ops with non-zero result value
Rather embarrassingly, our futex() FUTEX_WAKE_OP implementation doesn't
explicitly set the return value on the non-faulting path and instead
leaves it holding the result of the underlying atomic operation. This
means that any FUTEX_WAKE_OP atomic operation which computes a non-zero
value will be reported as having failed. Regrettably, I wrote the buggy
code back in 2011 and it was upstreamed as part of the initial arm64
support in 2012.

The reasons we appear to get away with this are:

  1. FUTEX_WAKE_OP is rarely used and therefore doesn't appear to get
     exercised by futex() test applications

  2. If the result of the atomic operation is zero, the system call
     behaves correctly

  3. Prior to version 2.25, the only operation used by GLIBC set the
     futex to zero, and therefore worked as expected. From 2.25 onwards,
     FUTEX_WAKE_OP is not used by GLIBC at all.

Fix the implementation by ensuring that the return value is either 0
to indicate that the atomic operation completed successfully, or -EFAULT
if we encountered a fault when accessing the user mapping.

Cc: <stable@kernel.org>
Fixes: 6170a97460 ("arm64: Atomic operations")
Signed-off-by: Will Deacon <will.deacon@arm.com>
2019-04-26 13:57:04 +01:00
Will Deacon
cbafee55b5 Merge branch 'core/speculation' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip into for-next/mitigations
Pull in core support for the "mitigations=" cmdline option from Thomas
Gleixner via -tip, which we can build on top of when we expose our
mitigation state via sysfs.
2019-04-26 13:32:20 +01:00
Kees Cook
be604c616c arm64: sysreg: Make mrs_s and msr_s macros work with Clang and LTO
Clang's integrated assembler does not allow assembly macros defined
in one inline asm block using the .macro directive to be used across
separate asm blocks. LLVM developers consider this a feature and not a
bug, recommending code refactoring:

  https://bugs.llvm.org/show_bug.cgi?id=19749

As binutils doesn't allow macros to be redefined, this change uses
UNDEFINE_MRS_S and UNDEFINE_MSR_S to define corresponding macros
in-place and workaround gcc and clang limitations on redefining macros
across different assembler blocks.

Specifically, the current state after preprocessing looks like this:

asm volatile(".macro mXX_s ... .endm");
void f()
{
	asm volatile("mXX_s a, b");
}

With GCC, it gives macro redefinition error because sysreg.h is included
in multiple source files, and assembler code for all of them is later
combined for LTO (I've seen an intermediate file with hundreds of
identical definitions).

With clang, it gives macro undefined error because clang doesn't allow
sharing macros between inline asm statements.

I also seem to remember catching another sort of undefined error with
GCC due to reordering of macro definition asm statement and generated
asm code for function that uses the macro.

The solution with defining and undefining for each use, while certainly
not elegant, satisfies both GCC and clang, LTO and non-LTO.

Co-developed-by: Alex Matveev <alxmtvv@gmail.com>
Co-developed-by: Yury Norov <ynorov@caviumnetworks.com>
Co-developed-by: Sami Tolvanen <samitolvanen@google.com>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Reviewed-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Will Deacon <will.deacon@arm.com>
2019-04-25 14:59:49 +01:00
Dave Martin
06a916feca arm64: Expose SVE2 features for userspace
This patch provides support for reporting the presence of SVE2 and
its optional features to userspace.

This will also enable visibility of SVE2 for guests, when KVM
support for SVE-enabled guests is available.

Signed-off-by: Dave Martin <Dave.Martin@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
2019-04-23 18:02:00 +01:00
Will Deacon
dd523791c9 arm64: Kconfig: Make CONFIG_COMPAT a menuconfig entry
Make CONFIG_COMPAT a menuconfig entry so that we can place
CONFIG_KUSER_HELPERS and CONFIG_ARMV8_DEPRECATED underneath it.

Signed-off-by: Will Deacon <will.deacon@arm.com>
2019-04-23 18:01:59 +01:00
Vincenzo Frascino
af1b3cf2c2 arm64: compat: Add KUSER_HELPERS config option
When kuser helpers are enabled the kernel maps the relative code at
a fixed address (0xffff0000). Making configurable the option to disable
them means that the kernel can remove this mapping and any access to
this memory area results in a sigfault.

Add a KUSER_HELPERS config option that can be used to disable the
mapping when it is turned off.

This option can be turned off if and only if the applications are
designed specifically for the platform and they do not make use of the
kuser helpers code.

Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
[will: Use IS_ENABLED() instead of #ifdef]
Signed-off-by: Will Deacon <will.deacon@arm.com>
2019-04-23 18:01:58 +01:00
Vincenzo Frascino
1255a7341b arm64: compat: Refactor aarch32_alloc_vdso_pages()
aarch32_alloc_vdso_pages() needs to be refactored to make it
easier to disable kuser helpers.

Divide the function in aarch32_alloc_kuser_vdso_page() and
aarch32_alloc_sigreturn_vdso_page().

Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
[will: Inlined sigpage allocation to simplify error paths]
Signed-off-by: Will Deacon <will.deacon@arm.com>
2019-04-23 18:01:58 +01:00
Vincenzo Frascino
d1e5ca64d5 arm64: compat: Split kuser32
To make it possible to disable kuser helpers in aarch32 we need to
divide the kuser and the sigreturn functionalities.

Split the current version of kuser32 in kuser32 (for kuser helpers)
and sigreturn32 (for sigreturn helpers).

Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
2019-04-23 18:01:57 +01:00
Vincenzo Frascino
0d747f6585 arm64: compat: Alloc separate pages for vectors and sigpage
For AArch32 tasks, we install a special "[vectors]" page that contains
the sigreturn trampolines and kuser helpers, which is mapped at a fixed
address specified by the kuser helpers ABI.

Having the sigreturn trampolines in the same page as the kuser helpers
makes it impossible to disable the kuser helpers independently.

Follow the Arm implementation, by moving the signal trampolines out of
the "[vectors]" page and into their own "[sigpage]".

Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
[will: tweaked comments and fixed sparse warning]
Signed-off-by: Will Deacon <will.deacon@arm.com>
2019-04-23 18:01:31 +01:00
Josh Poimboeuf
0336e04a65 s390/speculation: Support 'mitigations=' cmdline option
Configure s390 runtime CPU speculation bug mitigations in accordance
with the 'mitigations=' cmdline option.  This affects Spectre v1 and
Spectre v2.

The default behavior is unchanged.

Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Jiri Kosina <jkosina@suse.cz> (on x86)
Reviewed-by: Jiri Kosina <jkosina@suse.cz>
Cc: Borislav Petkov <bp@alien8.de>
Cc: "H . Peter Anvin" <hpa@zytor.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Jiri Kosina <jikos@kernel.org>
Cc: Waiman Long <longman@redhat.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Jon Masters <jcm@redhat.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: linuxppc-dev@lists.ozlabs.org
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: linux-s390@vger.kernel.org
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-arch@vger.kernel.org
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Tyler Hicks <tyhicks@canonical.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Steven Price <steven.price@arm.com>
Cc: Phil Auld <pauld@redhat.com>
Link: https://lkml.kernel.org/r/e4a161805458a5ec88812aac0307ae3908a030fc.1555085500.git.jpoimboe@redhat.com
2019-04-17 21:37:29 +02:00
Josh Poimboeuf
782e69efb3 powerpc/speculation: Support 'mitigations=' cmdline option
Configure powerpc CPU runtime speculation bug mitigations in accordance
with the 'mitigations=' cmdline option.  This affects Meltdown, Spectre
v1, Spectre v2, and Speculative Store Bypass.

The default behavior is unchanged.

Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Jiri Kosina <jkosina@suse.cz> (on x86)
Reviewed-by: Jiri Kosina <jkosina@suse.cz>
Cc: Borislav Petkov <bp@alien8.de>
Cc: "H . Peter Anvin" <hpa@zytor.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Jiri Kosina <jikos@kernel.org>
Cc: Waiman Long <longman@redhat.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Jon Masters <jcm@redhat.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: linuxppc-dev@lists.ozlabs.org
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: linux-s390@vger.kernel.org
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-arch@vger.kernel.org
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Tyler Hicks <tyhicks@canonical.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Steven Price <steven.price@arm.com>
Cc: Phil Auld <pauld@redhat.com>
Link: https://lkml.kernel.org/r/245a606e1a42a558a310220312d9b6adb9159df6.1555085500.git.jpoimboe@redhat.com
2019-04-17 21:37:29 +02:00
Josh Poimboeuf
d68be4c4d3 x86/speculation: Support 'mitigations=' cmdline option
Configure x86 runtime CPU speculation bug mitigations in accordance with
the 'mitigations=' cmdline option.  This affects Meltdown, Spectre v2,
Speculative Store Bypass, and L1TF.

The default behavior is unchanged.

Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Jiri Kosina <jkosina@suse.cz> (on x86)
Reviewed-by: Jiri Kosina <jkosina@suse.cz>
Cc: Borislav Petkov <bp@alien8.de>
Cc: "H . Peter Anvin" <hpa@zytor.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Jiri Kosina <jikos@kernel.org>
Cc: Waiman Long <longman@redhat.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Jon Masters <jcm@redhat.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: linuxppc-dev@lists.ozlabs.org
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: linux-s390@vger.kernel.org
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-arch@vger.kernel.org
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Tyler Hicks <tyhicks@canonical.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Steven Price <steven.price@arm.com>
Cc: Phil Auld <pauld@redhat.com>
Link: https://lkml.kernel.org/r/6616d0ae169308516cfdf5216bedd169f8a8291b.1555085500.git.jpoimboe@redhat.com
2019-04-17 21:37:28 +02:00
Josh Poimboeuf
98af845294 cpu/speculation: Add 'mitigations=' cmdline option
Keeping track of the number of mitigations for all the CPU speculation
bugs has become overwhelming for many users.  It's getting more and more
complicated to decide which mitigations are needed for a given
architecture.  Complicating matters is the fact that each arch tends to
have its own custom way to mitigate the same vulnerability.

Most users fall into a few basic categories:

a) they want all mitigations off;

b) they want all reasonable mitigations on, with SMT enabled even if
   it's vulnerable; or

c) they want all reasonable mitigations on, with SMT disabled if
   vulnerable.

Define a set of curated, arch-independent options, each of which is an
aggregation of existing options:

- mitigations=off: Disable all mitigations.

- mitigations=auto: [default] Enable all the default mitigations, but
  leave SMT enabled, even if it's vulnerable.

- mitigations=auto,nosmt: Enable all the default mitigations, disabling
  SMT if needed by a mitigation.

Currently, these options are placeholders which don't actually do
anything.  They will be fleshed out in upcoming patches.

Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Jiri Kosina <jkosina@suse.cz> (on x86)
Reviewed-by: Jiri Kosina <jkosina@suse.cz>
Cc: Borislav Petkov <bp@alien8.de>
Cc: "H . Peter Anvin" <hpa@zytor.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Jiri Kosina <jikos@kernel.org>
Cc: Waiman Long <longman@redhat.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Jon Masters <jcm@redhat.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: linuxppc-dev@lists.ozlabs.org
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: linux-s390@vger.kernel.org
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-arch@vger.kernel.org
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Tyler Hicks <tyhicks@canonical.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Steven Price <steven.price@arm.com>
Cc: Phil Auld <pauld@redhat.com>
Link: https://lkml.kernel.org/r/b07a8ef9b7c5055c3a4637c87d07c296d5016fe0.1555085500.git.jpoimboe@redhat.com
2019-04-17 21:37:28 +02:00
Kefeng Wang
36a2ba0775 ACPI/IORT: Reject platform device creation on NUMA node mapping failure
In a system where, through IORT firmware mappings, the SMMU device is
mapped to a NUMA node that is not online, the kernel bootstrap results
in the following crash:

  Unable to handle kernel paging request at virtual address 0000000000001388
  Mem abort info:
    ESR = 0x96000004
    Exception class = DABT (current EL), IL = 32 bits
    SET = 0, FnV = 0
    EA = 0, S1PTW = 0
  Data abort info:
    ISV = 0, ISS = 0x00000004
    CM = 0, WnR = 0
  [0000000000001388] user address but active_mm is swapper
  Internal error: Oops: 96000004 [#1] SMP
  Modules linked in:
  CPU: 5 PID: 1 Comm: swapper/0 Not tainted 5.0.0 #15
  pstate: 80c00009 (Nzcv daif +PAN +UAO)
  pc : __alloc_pages_nodemask+0x13c/0x1068
  lr : __alloc_pages_nodemask+0xdc/0x1068
  ...
  Process swapper/0 (pid: 1, stack limit = 0x(____ptrval____))
  Call trace:
   __alloc_pages_nodemask+0x13c/0x1068
   new_slab+0xec/0x570
   ___slab_alloc+0x3e0/0x4f8
   __slab_alloc+0x60/0x80
   __kmalloc_node_track_caller+0x10c/0x478
   devm_kmalloc+0x44/0xb0
   pinctrl_bind_pins+0x4c/0x188
   really_probe+0x78/0x2b8
   driver_probe_device+0x64/0x110
   device_driver_attach+0x74/0x98
   __driver_attach+0x9c/0xe8
   bus_for_each_dev+0x84/0xd8
   driver_attach+0x30/0x40
   bus_add_driver+0x170/0x218
   driver_register+0x64/0x118
   __platform_driver_register+0x54/0x60
   arm_smmu_driver_init+0x24/0x2c
   do_one_initcall+0xbc/0x328
   kernel_init_freeable+0x304/0x3ac
   kernel_init+0x18/0x110
   ret_from_fork+0x10/0x1c
  Code: f90013b5 b9410fa1 1a9f0694 b50014c2 (b9400804)
  ---[ end trace dfeaed4c373a32da ]--

Change the dev_set_proximity() hook prototype so that it returns a
value and make it return failure if the PXM->NUMA-node mapping
corresponds to an offline node, fixing the crash.

Acked-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Link: https://lore.kernel.org/linux-arm-kernel/20190315021940.86905-1-wangkefeng.wang@huawei.com/
Signed-off-by: Will Deacon <will.deacon@arm.com>
2019-04-16 18:16:24 +01:00
Vincenzo Frascino
81fb8736dd arm64: vdso: Fix clock_getres() for CLOCK_REALTIME
clock_getres() in the vDSO library has to preserve the same behaviour
of posix_get_hrtimer_res().

In particular, posix_get_hrtimer_res() does:

    sec = 0;
    ns = hrtimer_resolution;

where 'hrtimer_resolution' depends on whether or not high resolution
timers are enabled, which is a runtime decision.

The vDSO incorrectly returns the constant CLOCK_REALTIME_RES. Fix this
by exposing 'hrtimer_resolution' in the vDSO datapage and returning that
instead.

Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
[will: Use WRITE_ONCE(), move adr off COARSE path, renumber labels, use 'w' reg]
Signed-off-by: Will Deacon <will.deacon@arm.com>
2019-04-16 18:15:56 +01:00
Nishad Kamdar
22e6c8087e arm64: Use the correct style for SPDX License Identifier
This patch corrects the SPDX License Identifier style
in the arm64 Hardware Architecture related files.

Suggested-by: Joe Perches <joe@perches.com>
Signed-off-by: Nishad Kamdar <nishadkamdar@gmail.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
2019-04-16 16:28:01 +01:00
Mark Rutland
131e135f7f arm64: instrument smp_{load_acquire,store_release}
Our __smp_store_release() and __smp_load_acquire() macros use inline
assembly, which is opaque to kasan. This means that kasan can't catch
erroneous use of these.

This patch adds kasan instrumentation to both.

Cc: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
[will: consistently use *p as argument to sizeof]
Signed-off-by: Will Deacon <will.deacon@arm.com>
2019-04-16 16:28:00 +01:00
Miles Chen
eea1bb2248 arm64: mm: check virtual addr in virt_to_page() if CONFIG_DEBUG_VIRTUAL=y
This change uses the original virt_to_page() (the one with __pa()) to
check the given virtual address if CONFIG_DEBUG_VIRTUAL=y.

Recently, I worked on a bug: a driver passes a symbol address to
dma_map_single() and the virt_to_page() (called by dma_map_single())
does not work for non-linear addresses after commit 9f2875912d
("arm64: mm: restrict virt_to_page() to the linear mapping").

I tried to trap the bug by enabling CONFIG_DEBUG_VIRTUAL but it
did not work - bacause the commit removes the __pa() from
virt_to_page() but CONFIG_DEBUG_VIRTUAL checks the virtual address
in __pa()/__virt_to_phys().

A simple solution is to use the original virt_to_page()
(the one with__pa()) if CONFIG_DEBUG_VIRTUAL=y.

Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Miles Chen <miles.chen@mediatek.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
2019-04-16 16:27:59 +01:00
Andrew Murray
b9585f53bc arm64: Advertise ARM64_HAS_DCPODP cpu feature
Advertise ARM64_HAS_DCPODP when both DC CVAP and DC CVADP are supported.

Even though we don't use this feature now, we provide it for consistency
with DCPOP and anticipate it being used in the future.

Signed-off-by: Andrew Murray <andrew.murray@arm.com>
Reviewed-by: Dave Martin <Dave.Martin@arm.com>
Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
2019-04-16 16:27:59 +01:00
Andrew Murray
04a1438e56 arm64: add CVADP support to the cache maintenance helper
Allow users of dcache_by_line_op to specify cvadp as an op.

Signed-off-by: Andrew Murray <andrew.murray@arm.com>
Reviewed-by: Dave Martin <Dave.Martin@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
2019-04-16 16:27:58 +01:00
Andrew Murray
671db58181 arm64: Expose DC CVADP to userspace
ARMv8.5 builds upon the ARMv8.2 DC CVAP instruction by introducing a DC
CVADP instruction which cleans the data cache to the point of deep
persistence. Let's expose this support via the arm64 ELF hwcaps.

Signed-off-by: Andrew Murray <andrew.murray@arm.com>
Reviewed-by: Dave Martin <Dave.Martin@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
2019-04-16 16:27:56 +01:00
Andrew Murray
d16ed4105f arm64: Handle trapped DC CVADP
The ARMv8.5 DC CVADP instruction may be trapped to EL1 via
SCTLR_EL1.UCI therefore let's provide a handler for it.

Just like the CVAP instruction we use a 'sys' instruction instead of
the 'dc' alias to avoid build issues with older toolchains.

Signed-off-by: Andrew Murray <andrew.murray@arm.com>
Reviewed-by: Mark Rutland <mark.rutland@arm.com>
Reviewed-by: Dave Martin <Dave.Martin@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
2019-04-16 16:27:36 +01:00
Andrew Murray
aec0bff757 arm64: HWCAP: encapsulate elf_hwcap
The introduction of AT_HWCAP2 introduced accessors which ensure that
hwcap features are set and tested appropriately.

Let's now mandate access to elf_hwcap via these accessors by making
elf_hwcap static within cpufeature.c.

Signed-off-by: Andrew Murray <andrew.murray@arm.com>
Reviewed-by: Dave Martin <Dave.Martin@arm.com>
Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
2019-04-16 16:27:35 +01:00