Commit Graph

2480 Commits

Author SHA1 Message Date
Torsten Duwe
3b23e4991f arm64: implement ftrace with regs
This patch implements FTRACE_WITH_REGS for arm64, which allows a traced
function's arguments (and some other registers) to be captured into a
struct pt_regs, allowing these to be inspected and/or modified. This is
a building block for live-patching, where a function's arguments may be
forwarded to another function. This is also necessary to enable ftrace
and in-kernel pointer authentication at the same time, as it allows the
LR value to be captured and adjusted prior to signing.

Using GCC's -fpatchable-function-entry=N option, we can have the
compiler insert a configurable number of NOPs between the function entry
point and the usual prologue. This also ensures functions are AAPCS
compliant (e.g. disabling inter-procedural register allocation).

For example, with -fpatchable-function-entry=2, GCC 8.1.0 compiles the
following:

| unsigned long bar(void);
|
| unsigned long foo(void)
| {
|         return bar() + 1;
| }

... to:

| <foo>:
|         nop
|         nop
|         stp     x29, x30, [sp, #-16]!
|         mov     x29, sp
|         bl      0 <bar>
|         add     x0, x0, #0x1
|         ldp     x29, x30, [sp], #16
|         ret

This patch builds the kernel with -fpatchable-function-entry=2,
prefixing each function with two NOPs. To trace a function, we replace
these NOPs with a sequence that saves the LR into a GPR, then calls an
ftrace entry assembly function which saves this and other relevant
registers:

| mov	x9, x30
| bl	<ftrace-entry>

Since patchable functions are AAPCS compliant (and the kernel does not
use x18 as a platform register), x9-x18 can be safely clobbered in the
patched sequence and the ftrace entry code.

There are now two ftrace entry functions, ftrace_regs_entry (which saves
all GPRs), and ftrace_entry (which saves the bare minimum). A PLT is
allocated for each within modules.

Signed-off-by: Torsten Duwe <duwe@suse.de>
[Mark: rework asm, comments, PLTs, initialization, commit message]
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Reviewed-by: Amit Daniel Kachhap <amit.kachhap@arm.com>
Reviewed-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Reviewed-by: Torsten Duwe <duwe@suse.de>
Tested-by: Amit Daniel Kachhap <amit.kachhap@arm.com>
Tested-by: Torsten Duwe <duwe@suse.de>
Cc: AKASHI Takahiro <takahiro.akashi@linaro.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Julien Thierry <jthierry@redhat.com>
Cc: Will Deacon <will@kernel.org>
2019-11-06 14:17:35 +00:00
Mark Rutland
1f377e043b arm64: asm-offsets: add S_FP
So that assembly code can more easily manipulate the FP (x29) within a
pt_regs, add an S_FP asm-offsets definition.

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Reviewed-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Reviewed-by: Torsten Duwe <duwe@suse.de>
Tested-by: Amit Daniel Kachhap <amit.kachhap@arm.com>
Tested-by: Torsten Duwe <duwe@suse.de>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will@kernel.org>
2019-11-06 14:17:34 +00:00
Mark Rutland
e3bf8a67f7 arm64: insn: add encoder for MOV (register)
For FTRACE_WITH_REGS, we're going to want to generate a MOV (register)
instruction as part of the callsite intialization. As MOV (register) is
an alias for ORR (shifted register), we can generate this with
aarch64_insn_gen_logical_shifted_reg(), but it's somewhat verbose and
difficult to read in-context.

Add a aarch64_insn_gen_move_reg() wrapper for this case so that we can
write callers in a more straightforward way.

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Reviewed-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Reviewed-by: Torsten Duwe <duwe@suse.de>
Tested-by: Amit Daniel Kachhap <amit.kachhap@arm.com>
Tested-by: Torsten Duwe <duwe@suse.de>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will@kernel.org>
2019-11-06 14:17:33 +00:00
Mark Rutland
f1a54ae9af arm64: module/ftrace: intialize PLT at load time
Currently we lazily-initialize a module's ftrace PLT at runtime when we
install the first ftrace call. To do so we have to apply a number of
sanity checks, transiently mark the module text as RW, and perform an
IPI as part of handling Neoverse-N1 erratum #1542419.

We only expect the ftrace trampoline to point at ftrace_caller() (AKA
FTRACE_ADDR), so let's simplify all of this by intializing the PLT at
module load time, before the module loader marks the module RO and
performs the intial I-cache maintenance for the module.

Thus we can rely on the module having been correctly intialized, and can
simplify the runtime work necessary to install an ftrace call in a
module. This will also allow for the removal of module_disable_ro().

Tested by forcing ftrace_make_call() to use the module PLT, and then
loading up a module after setting up ftrace with:

| echo ":mod:<module-name>" > set_ftrace_filter;
| echo function > current_tracer;
| modprobe <module-name>

Since FTRACE_ADDR is only defined when CONFIG_DYNAMIC_FTRACE is
selected, we wrap its use along with most of module_init_ftrace_plt()
with ifdeffery rather than using IS_ENABLED().

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Reviewed-by: Amit Daniel Kachhap <amit.kachhap@arm.com>
Reviewed-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Reviewed-by: Torsten Duwe <duwe@suse.de>
Tested-by: Amit Daniel Kachhap <amit.kachhap@arm.com>
Tested-by: Torsten Duwe <duwe@suse.de>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: James Morse <james.morse@arm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Will Deacon <will@kernel.org>
2019-11-06 14:17:32 +00:00
Mark Rutland
bd8b21d3dd arm64: module: rework special section handling
When we load a module, we have to perform some special work for a couple
of named sections. To do this, we iterate over all of the module's
sections, and perform work for each section we recognize.

To make it easier to handle the unexpected absence of a section, and to
make the section-specific logic easer to read, let's factor the section
search into a helper. Similar is already done in the core module loader,
and other architectures (and ideally we'd unify these in future).

If we expect a module to have an ftrace trampoline section, but it
doesn't have one, we'll now reject loading the module. When
ARM64_MODULE_PLTS is selected, any correctly built module should have
one (and this is assumed by arm64's ftrace PLT code) and the absence of
such a section implies something has gone wrong at build time.

Subsequent patches will make use of the new helper.

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Reviewed-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Reviewed-by: Torsten Duwe <duwe@suse.de>
Tested-by: Amit Daniel Kachhap <amit.kachhap@arm.com>
Tested-by: Torsten Duwe <duwe@suse.de>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: James Morse <james.morse@arm.com>
Cc: Will Deacon <will@kernel.org>
2019-11-06 14:17:31 +00:00
Rich Wiley
918e1946c8 arm64: kpti: Add NVIDIA's Carmel core to the KPTI whitelist
NVIDIA Carmel CPUs don't implement ID_AA64PFR0_EL1.CSV3 but
aren't susceptible to Meltdown, so add Carmel to kpti_safe_list[].

Signed-off-by: Rich Wiley <rwiley@nvidia.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2019-11-06 11:31:03 +00:00
Kees Cook
19f6bc32c6 arm64: Move EXCEPTION_TABLE to RO_DATA segment
Since the EXCEPTION_TABLE is read-only, collapse it into RO_DATA. Also
removes the redundant ALIGN, which is already present at the end of the
RO_DATA macro.

Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Borislav Petkov <bp@suse.de>
Acked-by: Will Deacon <will@kernel.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: linux-alpha@vger.kernel.org
Cc: linux-arch@vger.kernel.org
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-c6x-dev@linux-c6x.org
Cc: linux-ia64@vger.kernel.org
Cc: linuxppc-dev@lists.ozlabs.org
Cc: linux-s390@vger.kernel.org
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Michal Simek <monstr@monstr.eu>
Cc: Peter Collingbourne <pcc@google.com>
Cc: Rick Edgecombe <rick.p.edgecombe@intel.com>
Cc: Segher Boessenkool <segher@kernel.crashing.org>
Cc: x86-ml <x86@kernel.org>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Link: https://lkml.kernel.org/r/20191029211351.13243-19-keescook@chromium.org
2019-11-04 18:02:35 +01:00
Kees Cook
c9174047b4 vmlinux.lds.h: Replace RW_DATA_SECTION with RW_DATA
Rename RW_DATA_SECTION to RW_DATA. (Calling this a "section" is a lie,
since it's multiple sections and section flags cannot be applied to
the macro.)

Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Borislav Petkov <bp@suse.de>
Acked-by: Heiko Carstens <heiko.carstens@de.ibm.com> # s390
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org> # m68k
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: linux-alpha@vger.kernel.org
Cc: linux-arch@vger.kernel.org
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-c6x-dev@linux-c6x.org
Cc: linux-ia64@vger.kernel.org
Cc: linux-s390@vger.kernel.org
Cc: linuxppc-dev@lists.ozlabs.org
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Michal Simek <monstr@monstr.eu>
Cc: Rick Edgecombe <rick.p.edgecombe@intel.com>
Cc: Segher Boessenkool <segher@kernel.crashing.org>
Cc: Will Deacon <will@kernel.org>
Cc: x86-ml <x86@kernel.org>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Link: https://lkml.kernel.org/r/20191029211351.13243-14-keescook@chromium.org
2019-11-04 15:57:41 +01:00
Kees Cook
eaf937075c vmlinux.lds.h: Move NOTES into RO_DATA
The .notes section should be non-executable read-only data. As such,
move it to the RO_DATA macro instead of being per-architecture defined.

Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Borislav Petkov <bp@suse.de>
Acked-by: Heiko Carstens <heiko.carstens@de.ibm.com> # s390
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: linux-alpha@vger.kernel.org
Cc: linux-arch@vger.kernel.org
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-c6x-dev@linux-c6x.org
Cc: linux-ia64@vger.kernel.org
Cc: linux-s390@vger.kernel.org
Cc: linuxppc-dev@lists.ozlabs.org
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Michal Simek <monstr@monstr.eu>
Cc: Rick Edgecombe <rick.p.edgecombe@intel.com>
Cc: Segher Boessenkool <segher@kernel.crashing.org>
Cc: Will Deacon <will@kernel.org>
Cc: x86-ml <x86@kernel.org>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Link: https://lkml.kernel.org/r/20191029211351.13243-11-keescook@chromium.org
2019-11-04 15:34:41 +01:00
Shaokun Zhang
9ef8567ccf arm64: perf: Simplify the ARMv8 PMUv3 event attributes
For each PMU event, there is a ARMV8_EVENT_ATTR(xx, XX) and
&armv8_event_attr_xx.attr.attr. Let's redefine the ARMV8_EVENT_ATTR
to simplify the armv8_pmuv3_event_attrs.

Cc: Will Deacon <will@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Shaokun Zhang <zhangshaokun@hisilicon.com>
[will: Dropped unnecessary array syntax]
Signed-off-by: Will Deacon <will@kernel.org>
2019-11-01 14:51:19 +00:00
Florian Fainelli
1cf45b8fdb arm64: apply ARM64_ERRATUM_843419 workaround for Brahma-B53 core
The Broadcom Brahma-B53 core is susceptible to the issue described by
ARM64_ERRATUM_843419 so this commit enables the workaround to be applied
when executing on that core.

Since there are now multiple entries to match, we must convert the
existing ARM64_ERRATUM_843419 into an erratum list and use
cpucap_multi_entry_cap_matches to match our entries.

Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: Will Deacon <will@kernel.org>
2019-11-01 10:47:37 +00:00
Florian Fainelli
e059770cb1 arm64: Brahma-B53 is SSB and spectre v2 safe
Add the Brahma-B53 CPU (all versions) to the whitelists of CPUs for the
SSB and spectre v2 mitigations.

Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: Will Deacon <will@kernel.org>
2019-11-01 10:47:37 +00:00
Doug Berger
bfc97f9f19 arm64: apply ARM64_ERRATUM_845719 workaround for Brahma-B53 core
The Broadcom Brahma-B53 core is susceptible to the issue described by
ARM64_ERRATUM_845719 so this commit enables the workaround to be applied
when executing on that core.

Since there are now multiple entries to match, we must convert the
existing ARM64_ERRATUM_845719 into an erratum list.

Signed-off-by: Doug Berger <opendmb@gmail.com>
Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: Will Deacon <will@kernel.org>
2019-11-01 10:47:37 +00:00
Bjorn Andersson
36c602dcdd arm64: cpufeature: Enable Qualcomm Falkor errata 1009 for Kryo
The Kryo cores share errata 1009 with Falkor, so add their model
definitions and enable it for them as well.

Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
[will: Update entry in silicon-errata.rst]
Signed-off-by: Will Deacon <will@kernel.org>
2019-10-31 13:22:12 +00:00
Bjorn Andersson
d4af3c4b81 arm64: cpufeature: Enable Qualcomm Falkor/Kryo errata 1003
With the introduction of 'cce360b54ce6 ("arm64: capabilities: Filter the
entries based on a given mask")' the Qualcomm Falkor/Kryo errata 1003 is
no long applied.

The result of not applying errata 1003 is that MSM8996 runs into various
RCU stalls and fails to boot most of the times.

Give 1003 a "type" to ensure they are not filtered out in
update_cpu_capabilities().

Fixes: cce360b54c ("arm64: capabilities: Filter the entries based on a given mask")
Cc: stable@vger.kernel.org
Reported-by: Mark Brown <broonie@kernel.org>
Suggested-by: Will Deacon <will@kernel.org>
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Signed-off-by: Will Deacon <will@kernel.org>
2019-10-29 17:18:50 +00:00
Catalin Marinas
8301ae822d Merge branch 'for-next/entry-s-to-c' into for-next/core
Move the synchronous exception paths from entry.S into a C file to
improve the code readability.

* for-next/entry-s-to-c:
  arm64: entry-common: don't touch daif before bp-hardening
  arm64: Remove asmlinkage from updated functions
  arm64: entry: convert el0_sync to C
  arm64: entry: convert el1_sync to C
  arm64: add local_daif_inherit()
  arm64: Add prototypes for functions called by entry.S
  arm64: remove __exception annotations
2019-10-28 17:02:56 +00:00
Catalin Marinas
346f6a4636 Merge branch 'kvm-arm64/erratum-1319367' of git://git.kernel.org/pub/scm/linux/kernel/git/maz/arm-platforms into for-next/core
Similarly to erratum 1165522 that affects Cortex-A76, A57 and A72
respectively suffer from errata 1319537 and 1319367, potentially
resulting in TLB corruption if the CPU speculates an AT instruction
while switching guests.

The fix is slightly more involved since we don't have VHE to help us
here, but the idea is the same: when switching a guest in, we must
prevent any speculated AT from being able to parse the page tables
until S2 is up and running. Only at this stage can we allow AT to take
place.

For this, we always restore the guest sysregs first, except for its
SCTLR and TCR registers, which must be set with SCTLR.M=1 and
TCR.EPD{0,1} = {1, 1}, effectively disabling the PTW and TLB
allocation. Once S2 is setup, we restore the guest's SCTLR and
TCR. Similar things must be done on TLB invalidation...

* 'kvm-arm64/erratum-1319367' of git://git.kernel.org/pub/scm/linux/kernel/git/maz/arm-platforms:
  arm64: Enable and document ARM errata 1319367 and 1319537
  arm64: KVM: Prevent speculative S1 PTW when restoring vcpu context
  arm64: KVM: Disable EL1 PTW when invalidating S2 TLBs
  arm64: KVM: Reorder system register restoration and stage-2 activation
  arm64: Add ARM64_WORKAROUND_1319367 for all A57 and A72 versions
2019-10-28 16:22:49 +00:00
Catalin Marinas
6a036afb55 Merge branch 'for-next/neoverse-n1-stale-instr' into for-next/core
Neoverse-N1 cores with the 'COHERENT_ICACHE' feature may fetch stale
instructions when software depends on prefetch-speculation-protection
instead of explicit synchronization. [0]

The workaround is to trap I-Cache maintenance and issue an
inner-shareable TLBI. The affected cores have a Coherent I-Cache, so the
I-Cache maintenance isn't necessary. The core tells user-space it can
skip it with CTR_EL0.DIC. We also have to trap this register to hide the
bit forcing DIC-aware user-space to perform the maintenance.

To avoid trapping all cache-maintenance, this workaround depends on
a firmware component that only traps I-cache maintenance from EL0 and
performs the workaround.

For user-space, the kernel's work is to trap CTR_EL0 to hide DIC, and
produce a fake IminLine. EL3 traps the now-necessary I-Cache maintenance
and performs the inner-shareable-TLBI that makes everything better.

[0] https://developer.arm.com/docs/sden885747/latest/arm-neoverse-n1-mp050-software-developer-errata-notice

* for-next/neoverse-n1-stale-instr:
  arm64: Silence clang warning on mismatched value/register sizes
  arm64: compat: Workaround Neoverse-N1 #1542419 for compat user-space
  arm64: Fake the IminLine size on systems affected by Neoverse-N1 #1542419
  arm64: errata: Hide CTR_EL0.DIC on systems affected by Neoverse-N1 #1542419
2019-10-28 16:12:40 +00:00
James Morse
bfe298745a arm64: entry-common: don't touch daif before bp-hardening
The previous patches mechanically transformed the assembly version of
entry.S to entry-common.c for synchronous exceptions.

The C version of local_daif_restore() doesn't quite do the same thing
as the assembly versions if pseudo-NMI is in use. In particular,
| local_daif_restore(DAIF_PROCCTX_NOIRQ)
will still allow pNMI to be delivered. This is not the behaviour
do_el0_ia_bp_hardening() and do_sp_pc_abort() want as it should not
be possible for the PMU handler to run as an NMI until the bp-hardening
sequence has run.

The bp-hardening calls were placed where they are because this was the
first C code to run after the relevant exceptions. As we've now moved
that point earlier, move the checks and calls earlier too.

This makes it clearer that this stuff runs before any kind of exception,
and saves modifying PSTATE twice.

Signed-off-by: James Morse <james.morse@arm.com>
Reviewed-by: Mark Rutland <mark.rutland@arm.com>
Cc: Julien Thierry <julien.thierry.kdev@gmail.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2019-10-28 11:22:54 +00:00
James Morse
afa7c0e5b9 arm64: Remove asmlinkage from updated functions
Now that the callers of these functions have moved into C, they no longer
need the asmlinkage annotation. Remove it.

Signed-off-by: James Morse <james.morse@arm.com>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2019-10-28 11:22:51 +00:00
Mark Rutland
582f95835a arm64: entry: convert el0_sync to C
This is largely a 1-1 conversion of asm to C, with a couple of caveats.

The el0_sync{_compat} switches explicitly handle all the EL0 debug
cases, so el0_dbg doesn't have to try to bail out for unexpected EL1
debug ESR values. This also means that an unexpected vector catch from
AArch32 is routed to el0_inv.

We *could* merge the native and compat switches, which would make the
diffstat negative, but I've tried to stay as close to the existing
assembly as possible for the moment.

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
[split out of a bigger series, added nokprobes. removed irq trace
 calls as the C helpers do this. renamed el0_dbg's use of FAR]
Signed-off-by: James Morse <james.morse@arm.com>
Reviewed-by: Mark Rutland <mark.rutland@arm.com>
Cc: Julien Thierry <julien.thierry.kdev@gmail.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2019-10-28 11:22:49 +00:00
Mark Rutland
ed3768db58 arm64: entry: convert el1_sync to C
This patch converts the EL1 sync entry assembly logic to C code.

Doing this will allow us to make changes in a slightly more
readable way. A case in point is supporting kernel-first RAS.
do_sea() should be called on the CPU that took the fault.

Largely the assembly code is converted to C in a relatively
straightforward manner.

Since all sync sites share a common asm entry point, the ASM_BUG()
instances are no longer required for effective backtraces back to
assembly, and we don't need similar BUG() entries.

The ESR_ELx.EC codes for all (supported) debug exceptions are now
checked in the el1_sync_handler's switch statement, which renders the
check in el1_dbg redundant. This both simplifies the el1_dbg handler,
and makes the EL1 exception handling more robust to
currently-unallocated ESR_ELx.EC encodings.

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
[split out of a bigger series, added nokprobes, moved prototypes]
Signed-off-by: James Morse <james.morse@arm.com>
Reviewed-by: Mark Rutland <mark.rutland@arm.com>
Cc: Julien Thierry <julien.thierry.kdev@gmail.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2019-10-28 11:22:47 +00:00
James Morse
b6e43c0e31 arm64: remove __exception annotations
Since commit 7326749801 ("arm64: unwind: reference pt_regs via embedded
stack frame") arm64 has not used the __exception annotation to dump
the pt_regs during stack tracing. in_exception_text() has no callers.

This annotation is only used to blacklist kprobes, it means the same as
__kprobes.

Section annotations like this require the functions to be grouped
together between the start/end markers, and placed according to
the linker script. For kprobes we also have NOKPROBE_SYMBOL() which
logs the symbol address in a section that kprobes parses and
blacklists at boot.

Using NOKPROBE_SYMBOL() instead lets kprobes publish the list of
blacklisted symbols, and saves us from having an arm64 specific
spelling of __kprobes.

do_debug_exception() already has a NOKPROBE_SYMBOL() annotation.

Signed-off-by: James Morse <james.morse@arm.com>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2019-10-28 11:22:38 +00:00
Catalin Marinas
27a22fbdee arm64: Silence clang warning on mismatched value/register sizes
Clang reports a warning on the __tlbi(aside1is, 0) macro expansion since
the value size does not match the register size specified in the inline
asm. Construct the ASID value using the __TLBI_VADDR() macro.

Fixes: 222fc0c850 ("arm64: compat: Workaround Neoverse-N1 #1542419 for compat user-space")
Reported-by: Nathan Chancellor <natechancellor@gmail.com>
Cc: James Morse <james.morse@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2019-10-28 09:13:21 +00:00
James Morse
222fc0c850 arm64: compat: Workaround Neoverse-N1 #1542419 for compat user-space
Compat user-space is unable to perform ICIMVAU instructions from
user-space. Instead it uses a compat-syscall. Add the workaround for
Neoverse-N1 #1542419 to this code path.

Signed-off-by: James Morse <james.morse@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2019-10-25 17:48:44 +01:00
James Morse
ee9d90be9d arm64: Fake the IminLine size on systems affected by Neoverse-N1 #1542419
Systems affected by Neoverse-N1 #1542419 support DIC so do not need to
perform icache maintenance once new instructions are cleaned to the PoU.
For the errata workaround, the kernel hides DIC from user-space, so that
the unnecessary cache maintenance can be trapped by firmware.

To reduce the number of traps, produce a fake IminLine value based on
PAGE_SIZE.

Signed-off-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>
2019-10-25 17:48:44 +01:00
James Morse
05460849c3 arm64: errata: Hide CTR_EL0.DIC on systems affected by Neoverse-N1 #1542419
Cores affected by Neoverse-N1 #1542419 could execute a stale instruction
when a branch is updated to point to freshly generated instructions.

To workaround this issue we need user-space to issue unnecessary
icache maintenance that we can trap. Start by hiding CTR_EL0.DIC.

Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: James Morse <james.morse@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2019-10-25 17:46:40 +01:00
Yunfeng Ye
bfcef4ab1d arm64: psci: Reduce the waiting time for cpu_psci_cpu_kill()
In cases like suspend-to-disk and suspend-to-ram, a large number of CPU
cores need to be shut down. At present, the CPU hotplug operation is
serialised, and the CPU cores can only be shut down one by one. In this
process, if PSCI affinity_info() does not return LEVEL_OFF quickly,
cpu_psci_cpu_kill() needs to wait for 10ms. If hundreds of CPU cores
need to be shut down, it will take a long time.

Normally, there is no need to wait 10ms in cpu_psci_cpu_kill(). So
change the wait interval from 10 ms to max 1 ms and use usleep_range()
instead of msleep() for more accurate timer.

In addition, reducing the time interval will increase the messages
output, so remove the "Retry ..." message, instead, track time and
output to the the sucessful message.

Signed-off-by: Yunfeng Ye <yeyunfeng@huawei.com>
Reviewed-by: Sudeep Holla <sudeep.holla@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2019-10-25 16:29:11 +01:00
Shaokun Zhang
7db3e57e6a arm64: cpufeature: Fix typos in comment
Fix up one typos: CTR_E0 -> CTR_EL0

Cc: Will Deacon <will@kernel.org>
Acked-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Shaokun Zhang <zhangshaokun@hisilicon.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2019-10-25 16:19:44 +01:00
Steven Price
e0685fa228 arm64: Retrieve stolen time as paravirtualized guest
Enable paravirtualization features when running under a hypervisor
supporting the PV_TIME_ST hypercall.

For each (v)CPU, we ask the hypervisor for the location of a shared
page which the hypervisor will use to report stolen time to us. We set
pv_time_ops to the stolen time function which simply reads the stolen
value from the shared page for a VCPU. We guarantee single-copy
atomicity using READ_ONCE which means we can also read the stolen
time for another VCPU than the currently running one while it is
potentially being updated by the hypervisor.

Signed-off-by: Steven Price <steven.price@arm.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
2019-10-21 19:20:31 +01:00
Steven Price
ce4d5ca2b9 arm/arm64: Make use of the SMCCC 1.1 wrapper
Rather than directly choosing which function to use based on
psci_ops.conduit, use the new arm_smccc_1_1 wrapper instead.

In some cases we still need to do some operations based on the
conduit, but the code duplication is removed.

No functional change.

Signed-off-by: Steven Price <steven.price@arm.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
2019-10-21 19:20:30 +01:00
Marc Zyngier
f75e2294a4 arm64: Add ARM64_WORKAROUND_1319367 for all A57 and A72 versions
Rework the EL2 vector hardening that is only selected for A57 and A72
so that the table can also be used for ARM64_WORKAROUND_1319367.

Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
2019-10-18 12:36:56 +01:00
Kefeng Wang
a74ec64af2 arm64: Use pr_warn instead of pr_warning
As said in commit f2c2cbcc35 ("powerpc: Use pr_warn instead of
pr_warning"), removing pr_warning so all logging messages use a
consistent <prefix>_warn style. Let's do it.

Link: http://lkml.kernel.org/r/20191018031850.48498-2-wangkefeng.wang@huawei.com
To: linux-kernel@vger.kernel.org
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Acked-by: Will Deacon <will@kernel.org>
Reviewed-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Signed-off-by: Petr Mladek <pmladek@suse.com>
2019-10-18 10:28:33 +02:00
Will Deacon
777d062e5b Merge branch 'errata/tx2-219' into for-next/fixes
Workaround for Cavium/Marvell ThunderX2 erratum #219.

* errata/tx2-219:
  arm64: Allow CAVIUM_TX2_ERRATUM_219 to be selected
  arm64: Avoid Cavium TX2 erratum 219 when switching TTBR
  arm64: Enable workaround for Cavium TX2 erratum 219 when running SMT
  arm64: KVM: Trap VM ops when ARM64_WORKAROUND_CAVIUM_TX2_219_TVM is set
2019-10-17 13:42:42 -07:00
Will Deacon
597399d0cb arm64: tags: Preserve tags for addresses translated via TTBR1
Sign-extending TTBR1 addresses when converting to an untagged address
breaks the documented POSIX semantics for mlock() in some obscure error
cases where we end up returning -EINVAL instead of -ENOMEM as a direct
result of rewriting the upper address bits.

Rework the untagged_addr() macro to preserve the upper address bits for
TTBR1 addresses and only clear the tag bits for user addresses. This
matches the behaviour of the 'clear_address_tag' assembly macro, so
rename that and align the implementations at the same time so that they
use the same instruction sequences for the tag manipulation.

Link: https://lore.kernel.org/stable/20191014162651.GF19200@arrakis.emea.arm.com/
Reported-by: Jan Stancek <jstancek@redhat.com>
Tested-by: Jan Stancek <jstancek@redhat.com>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Tested-by: Catalin Marinas <catalin.marinas@arm.com>
Reviewed-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Tested-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Reviewed-by: Andrey Konovalov <andreyknvl@google.com>
Signed-off-by: Will Deacon <will@kernel.org>
2019-10-16 10:11:38 -07:00
Julien Thierry
19c95f261c arm64: entry.S: Do not preempt from IRQ before all cpufeatures are enabled
Preempting from IRQ-return means that the task has its PSTATE saved
on the stack, which will get restored when the task is resumed and does
the actual IRQ return.

However, enabling some CPU features requires modifying the PSTATE. This
means that, if a task was scheduled out during an IRQ-return before all
CPU features are enabled, the task might restore a PSTATE that does not
include the feature enablement changes once scheduled back in.

* Task 1:

PAN == 0 ---|                          |---------------
            |                          |<- return from IRQ, PSTATE.PAN = 0
            | <- IRQ                   |
            +--------+ <- preempt()  +--
                                     ^
                                     |
                                     reschedule Task 1, PSTATE.PAN == 1
* Init:
        --------------------+------------------------
                            ^
                            |
                            enable_cpu_features
                            set PSTATE.PAN on all CPUs

Worse than this, since PSTATE is untouched when task switching is done,
a task missing the new bits in PSTATE might affect another task, if both
do direct calls to schedule() (outside of IRQ/exception contexts).

Fix this by preventing preemption on IRQ-return until features are
enabled on all CPUs.

This way the only PSTATE values that are saved on the stack are from
synchronous exceptions. These are expected to be fatal this early, the
exception is BRK for WARN_ON(), but as this uses do_debug_exception()
which keeps IRQs masked, it shouldn't call schedule().

Signed-off-by: Julien Thierry <julien.thierry@arm.com>
[james: Replaced a really cool hack, with an even simpler static key in C.
 expanded commit message with Julien's cover-letter ascii art]
Signed-off-by: James Morse <james.morse@arm.com>
Signed-off-by: Will Deacon <will@kernel.org>
2019-10-16 09:51:43 -07:00
Marc Zyngier
f226650494 arm64: Relax ICC_PMR_EL1 accesses when ICC_CTLR_EL1.PMHE is clear
The GICv3 architecture specification is incredibly misleading when it
comes to PMR and the requirement for a DSB. It turns out that this DSB
is only required if the CPU interface sends an Upstream Control
message to the redistributor in order to update the RD's view of PMR.

This message is only sent when ICC_CTLR_EL1.PMHE is set, which isn't
the case in Linux. It can still be set from EL3, so some special care
is required. But the upshot is that in the (hopefuly large) majority
of the cases, we can drop the DSB altogether.

This relies on a new static key being set if the boot CPU has PMHE
set. The drawback is that this static key has to be exported to
modules.

Cc: Will Deacon <will@kernel.org>
Cc: James Morse <james.morse@arm.com>
Cc: Julien Thierry <julien.thierry.kdev@gmail.com>
Cc: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2019-10-15 12:26:09 +01:00
Pavel Tatashin
8c551f919a arm64: hibernate: check pgd table allocation
There is a bug in create_safe_exec_page(), when page table is allocated
it is not checked that table is allocated successfully:

But it is dereferenced in: pgd_none(READ_ONCE(*pgdp)).  Check that
allocation was successful.

Fixes: 82869ac57b ("arm64: kernel: Add support for hibernate/suspend-to-disk")
Reviewed-by: James Morse <james.morse@arm.com>
Signed-off-by: Pavel Tatashin <pasha.tatashin@soleen.com>
Signed-off-by: Will Deacon <will@kernel.org>
2019-10-14 17:57:29 -07:00
Julien Grall
ec52c7134b arm64: cpufeature: Treat ID_AA64ZFR0_EL1 as RAZ when SVE is not enabled
If CONFIG_ARM64_SVE=n then we fail to report ID_AA64ZFR0_EL1 as 0 when
read by userspace, despite being required by the architecture. Although
this is theoretically a change in ABI, userspace will first check for
the presence of SVE via the HWCAP or the ID_AA64PFR0_EL1.SVE field
before probing the ID_AA64ZFR0_EL1 register. Given that these are
reported correctly for this configuration, we can safely tighten up the
current behaviour.

Ensure ID_AA64ZFR0_EL1 is treated as RAZ when CONFIG_ARM64_SVE=n.

Signed-off-by: Julien Grall <julien.grall@arm.com>
Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Reviewed-by: Mark Rutland <mark.rutland@arm.com>
Reviewed-by: Dave Martin <dave.martin@arm.com>
Fixes: 06a916feca ("arm64: Expose SVE2 features for userspace")
Signed-off-by: Will Deacon <will@kernel.org>
2019-10-14 17:56:57 -07:00
Mark Rutland
e6ea46511b firmware: arm_sdei: use common SMCCC_CONDUIT_*
Now that we have common definitions for SMCCC conduits, move the SDEI
code over to them, and remove the SDEI-specific definitions.

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

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Acked-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Acked-by: James Morse <james.morse@arm.com>
Acked-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2019-10-14 10:55:14 +01:00
Mark Rutland
c98bd29917 arm64: errata: use arm_smccc_1_1_get_conduit()
Now that we have arm_smccc_1_1_get_conduit(), we can hide the PSCI
implementation details from the arm64 cpu errata code, so let's do so.

As arm_smccc_1_1_get_conduit() implicitly checks that the SMCCC version
is at least SMCCC_VERSION_1_1, we no longer need to check this
explicitly where switch statements have a default case, e.g. in
has_ssbd_mitigation().

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

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Cc: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Cc: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2019-10-14 10:55:13 +01:00
Christian Brauner
fefad9ef58 seccomp: simplify secure_computing()
Afaict, the struct seccomp_data argument to secure_computing() is unused
by all current callers. So let's remove it.
The argument was added in [1]. It was added because having the arch
supply the syscall arguments used to be faster than having it done by
secure_computing() (cf. Andy's comment in [2]). This is not true anymore
though.

/* References */
[1]: 2f275de5d1 ("seccomp: Add a seccomp_data parameter secure_computing()")
[2]: https://lore.kernel.org/r/CALCETrU_fs_At-hTpr231kpaAd0z7xJN4ku-DvzhRU6cvcJA_w@mail.gmail.com

Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Will Drewry <wad@chromium.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-parisc@vger.kernel.org
Cc: linux-s390@vger.kernel.org
Cc: linux-um@lists.infradead.org
Cc: x86@kernel.org
Acked-by: Borislav Petkov <bp@suse.de>
Acked-by: Andy Lutomirski <luto@kernel.org>
Link: https://lore.kernel.org/r/20190924064420.6353-1-christian.brauner@ubuntu.com
Signed-off-by: Kees Cook <keescook@chromium.org>
2019-10-10 14:55:24 -07:00
Yunfeng Ye
3e7c93bd04 arm64: armv8_deprecated: Checking return value for memory allocation
There are no return value checking when using kzalloc() and kcalloc() for
memory allocation. so add it.

Signed-off-by: Yunfeng Ye <yeyunfeng@huawei.com>
Signed-off-by: Will Deacon <will@kernel.org>
2019-10-08 13:34:04 +01:00
Marc Zyngier
9405447ef7 arm64: Avoid Cavium TX2 erratum 219 when switching TTBR
As a PRFM instruction racing against a TTBR update can have undesirable
effects on TX2, NOP-out such PRFM on cores that are affected by
the TX2-219 erratum.

Cc: <stable@vger.kernel.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Will Deacon <will@kernel.org>
2019-10-08 12:25:25 +01:00
Marc Zyngier
93916beb70 arm64: Enable workaround for Cavium TX2 erratum 219 when running SMT
It appears that the only case where we need to apply the TX2_219_TVM
mitigation is when the core is in SMT mode. So let's condition the
enabling on detecting a CPU whose MPIDR_EL1.Aff0 is non-zero.

Cc: <stable@vger.kernel.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Will Deacon <will@kernel.org>
2019-10-08 12:25:25 +01:00
Will Deacon
eff9cb67be arm64: vdso32: Rename COMPATCC to CC_COMPAT
For consistency with CROSS_COMPILE_COMPAT, mechanically rename COMPATCC
to CC_COMPAT so that specifying aspects of the compat vDSO toolchain in
the environment isn't needlessly confusing.

Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Will Deacon <will@kernel.org>
2019-10-07 13:32:13 +01:00
Will Deacon
7424ee2b16 arm64: vdso32: Pass '--target' option to clang via VDSO_CAFLAGS
Directly passing the '--target' option to clang by appending to
COMPATCC does not work if COMPATCC has been specified explicitly as
an argument to Make unless the 'override' directive is used, which is
ugly and different to what is done in the top-level Makefile.

Move the '--target' option for clang out of COMPATCC and into
VDSO_CAFLAGS, where it will be picked up when compiling and assembling
the 32-bit vDSO under clang.

Reported-by: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Will Deacon <will@kernel.org>
2019-10-07 13:32:09 +01:00
Will Deacon
c71e88c437 arm64: vdso32: Don't use KBUILD_CPPFLAGS unconditionally
KBUILD_CPPFLAGS is defined differently depending on whether the main
compiler is clang or not. This means that it is not possible to build
the compat vDSO with GCC if the rest of the kernel is built with clang.

Define VDSO_CPPFLAGS directly to break this dependency and allow a clang
kernel to build a compat vDSO with GCC:

  $ make ARCH=arm64 CROSS_COMPILE=aarch64-linux-gnu- \
    CROSS_COMPILE_COMPAT=arm-linux-gnueabihf- CC=clang \
    COMPATCC=arm-linux-gnueabihf-gcc

Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Will Deacon <will@kernel.org>
2019-10-07 13:32:05 +01:00
Will Deacon
bcaf9b57e4 arm64: vdso32: Move definition of COMPATCC into vdso32/Makefile
There's no need to export COMPATCC, so just define it locally in the
vdso32/Makefile, which is the only place where it is used.

Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Will Deacon <will@kernel.org>
2019-10-07 13:32:02 +01:00
Vincenzo Frascino
a7f93103f8 arm64: vdso32: Remove jump label config option in Makefile
The jump labels are not used in vdso32 since it is not possible to run
runtime patching on them.

Remove the configuration option from the Makefile.

Cc: Will Deacon <will@kernel.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Tested-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Will Deacon <will@kernel.org>
2019-10-07 11:07:17 +01:00