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I don't think it is really possible to have a system where CPUID
enumerates support for XSAVE but that it does not have FP/SSE
(they are "legacy" features and always present).
But, I did manage to hit this case in qemu when I enabled its
somewhat shaky XSAVE support. The bummer is that the FPU is set
up before we parse the command-line or have *any* console support
including earlyprintk. That turned what should have been an easy
thing to debug in to a bit more of an odyssey.
So a BUG() here is worthless. All it does it guarantee that
if/when we hit this case we have an empty console. So, remove
the BUG() and try to limp along by disabling XSAVE and trying to
continue. Add a comment on why we are doing this, and also add
a common "out_disable" path for leaving fpu__init_system_xstate().
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Dave Hansen <dave@sr71.net>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Quentin Casasnovas <quentin.casasnovas@oracle.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20160720194551.63BB2B58@viggo.jf.intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Passing "nosmp" should boot the kernel with a single processor, without
provision to enable secondary CPUs even if they are present. "nosmp" is
implemented by setting maxcpus=0. At the moment we still mark the secondary
CPUs present even with nosmp, which allows the userspace to bring them
up. This patch corrects the smp_prepare_cpus() to honor the maxcpus == 0.
Commit 44dbcc93ab67145 ("arm64: Fix behavior of maxcpus=N") fixed the
behavior for maxcpus >= 1, but broke maxcpus = 0.
Fixes: 44dbcc93ab67 ("arm64: Fix behavior of maxcpus=N")
Cc: <stable@vger.kernel.org> # 4.7+
Cc: Will Deacon <will.deacon@arm.com>
Cc: James Morse <james.morse@arm.com>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Acked-by: Mark Rutland <mark.rutland@arm.com>
[catalin.marinas@arm.com: updated code comment]
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
In smp_prepare_boot_cpu(), we invoke cpuinfo_store_boot_cpu to store
the cpuinfo in a per-cpu ptr, before initialising the per-cpu offset for
the boot CPU. This patch reorders the sequence to make sure we initialise
the per-cpu offset before accessing the per-cpu area.
Commit 4b998ff1885eec ("arm64: Delay cpuinfo_store_boot_cpu") fixed the
issue where we modified the per-cpu area even before the kernel initialises
the per-cpu areas, but failed to wait until the boot cpu updated it's
offset.
Fixes: 4b998ff1885e ("arm64: Delay cpuinfo_store_boot_cpu")
Cc: <stable@vger.kernel.org> # 4.4+
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Add support for Intel's AVX-512 instructions to the instruction decoder.
AVX-512 instructions are documented in Intel Architecture Instruction
Set Extensions Programming Reference (February 2016).
AVX-512 instructions are identified by a EVEX prefix which, for the
purpose of instruction decoding, can be treated as though it were a
4-byte VEX prefix.
Existing instructions which can now accept an EVEX prefix need not be
further annotated in the op code map (x86-opcode-map.txt). In the case
of new instructions, the op code map is updated accordingly.
Also add associated Mask Instructions that are used to manipulate mask
registers used in AVX-512 instructions.
The 'perf tools' instruction decoder is updated in a subsequent patch.
And a representative set of instructions is added to the perf tools new
instructions test in a subsequent patch.
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Acked-by: Ingo Molnar <mingo@kernel.org>
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: X86 ML <x86@kernel.org>
Link: http://lkml.kernel.org/r/1469003437-32706-3-git-send-email-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
jprobe_return seems to have aged badly. Comments referring to
non-existent behaviours, and a dangerous habit of messing
with registers without telling the compiler.
This patches applies the following remedies:
- Fix the comments to describe the actual behaviour
- Tidy up the asm sequence to directly assign the
stack pointer without clobbering extra registers
- Mark the rest of the function as unreachable() so
that the compiler knows that there is no need for
an epilogue
- Stop making jprobe_return_break a global function
(you really don't want to call that guy, and it isn't
even a function).
Tested with tcp_probe.
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
This patch provides the necessary infrastructure to allow drivers
to be automatically loaded via udev. It implements the minimum
required to be able to use module_cpu_feature_match() to trigger
the GENERIC_CPU_AUTOPROBE mechanisms.
The features exposed are a mirror of the cpu_user_features
(converted to an offset from a mask). This decision was made to
ensure that the behavior between features for module loading and
userspace are consistent.
Signed-off-by: Alastair D'Silva <alastair@d-silva.org>
[mpe: Only define the bits we currently need]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
The iommu_table_ops::exchange() callback writes new TCE to the table and
returns old value and permission mask. The old TCE value is correctly
converted from BE to CPU endian; however permission mask was calculated
from BE value and therefore always returned DMA_NONE which could cause
memory leak on LE systems using VFIO SPAPR TCE IOMMU v1 driver.
This fixes pnv_tce_xchg() to have @oldtce a CPU endian.
Fixes: 05c6cfb9dce0 ("powerpc/iommu/powernv: Release replaced TCE")
Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
__hugepte_alloc() uses kmem_cache_zalloc() to allocate a zeroed PTE
and proceeds to use the newly allocated PTE. Add a memory barrier to
make sure that the other CPUs see a properly initialized PTE.
Based on a fix suggested by James Dykman.
Reported-by: James Dykman <jdykman@us.ibm.com>
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>
Tested-by: James Dykman <jdykman@us.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
In the module loader we process relocations, and for long jumps we
generate trampolines (aka stubs). At the call site for one of these
trampolines we usually need to generate a load instruction to restore
the TOC pointer into r2.
There is one exception however, which is calls to mcount() using the
mprofile-kernel ABI, they handle the TOC inside the stub, and so for
them we do not generate a TOC load.
The bug is in how the code in restore_r2() decides if it needs to
generate the TOC load. It does so by looking for a nop following the
branch, and if it sees a nop, it replaces it with the load. In general
the compiler has no reason to generate a nop following the mcount()
call and so that check works OK.
However if we combine a jump label at the start of a function, with an
early return, such that GCC applies the shrink-wrapping optimisation, we
can then end up with an mcount call followed immediately by a nop.
However the nop is not there for a TOC load, it is for the jump label.
That confuses restore_r2() into replacing the jump label nop with a TOC
load, which in turn confuses ftrace into replacing the mcount call with
a b +8 (fixed in the previous commit). The end result is we jump over
the jump label, which if it was supposed to return means we incorrectly
run the body of the function.
We have seen this in practice with some yet-to-be-merged patches that
use jump labels more extensively.
The fix is relatively simple, in restore_r2() we check for an
mprofile-kernel style mcount() call first, before looking for the
presence of a nop.
Fixes: 153086644fd1 ("powerpc/ftrace: Add support for -mprofile-kernel ftrace ABI")
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
In __ftrace_make_nop() (the 64-bit version), we have code to deal with
two ftrace ABIs. There is the original ABI, which looks mostly like a
function call, and then the mprofile-kernel ABI which is just a branch.
The code tries to handle both cases, by looking for the presence of a
load to restore the TOC pointer (PPC_INST_LD_TOC). If we detect the TOC
load, we assume the call site is for an mcount() call using the old ABI.
That means we patch the mcount() call with a b +8, to branch over the
TOC load.
However if the kernel was built with mprofile-kernel, then there will
never be a call site using the original ftrace ABI. If for some reason
we do see a TOC load, then it's there for a good reason, and we should
not jump over it.
So split the code, using the existing CC_USING_MPROFILE_KERNEL. Kernels
built with mprofile-kernel will only look for, and expect, the new ABI,
and similarly for the original ABI.
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
There is little enough differences now.
mpe: Add a/p/k/setup.h to contain the prototypes and empty versions of
functions we need, rather than using weak functions. Add a few other
empty versions to avoid as many #ifdefs as possible in the code.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Do it right after probe_machine() since it's about testing ppc_md,
and put the test in the common code.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
It makes more sense to do it before intializing xmon() as xmon might
use the info in there. We do want to register the console early
though in case we want some functioning printk's in the cpu map setup.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Matches 64-bit. Also move the call to the same spot as ppc64
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Also remove the completely osbolete comment. We *do* look in the
device-tree.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
It is now called right after platform probe, so the probe function
can just do the job.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
This converts all the 32-bit platforms to use the expanded device-tree
which is a pretty mechanical change. Unlike 64-bit, the 32-bit kernel
didn't rely on platform initializations to setup the MMU since it
sets it up entirely before probe_machine() so the move has comparatively
less consequences though it's a bigger patch.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
We no long need the machine type that early, so we can move probe_machine()
to after the device-tree has been expanded. This will allow further
consolidation.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Anything in there will be overwritten, so it helps catching nasty
bugs if we check that it's indeed full of NULL's before we do so.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Moving probe_machine() to after mmu init will cause the ppc_md
fields relative to the hash table management to be overwritten.
Since we have essentially disconnected the machine type from
the hash backend ops, finish the job by moving them to a different
structure.
The only callback that didn't quite fix is update_partition_table
since this is not specific to hash, so I moved it to a standalone
variable for now. We can revisit later if needed.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
[mpe: Fix ppc64e build failure in kexec]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
pmac_declare_of_platform_devices() is already a machine initcall, thus
it won't be called on a non-powermac machine. Testing for chrp there
is pointless.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Instead, check for FW_FEATURE_SPLPAR. This should be roughtly equivalent
as all pseries machiens that can have an HEA also support SPLPAR and
no other machine type does.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Use the device-tree instead as we'll be moving probe_machine()
out of early_setup
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
These days, memblocks is available later, so we can just allocate it
as part of iob_init.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
We move it into early_mmu_init() based on firmware features. For PS3,
we have to move the setting of these into early_init_devtree().
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
The SMU command buffer needs to be allocated below 2G using memblock.
In the past, this had to be done very early from the arch code as
memblock wasn't available past that point. That is no longer the
case though, smu_init() is called from setup_arch() when memblock
is still functional these days. So move the allocation to the
SMU driver itself.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
The various calls to establish exception endianness and AIL are
now done from a single point using already established CPU and FW
feature bits to decide what to do.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
We move the function itself to pseries/firmware.c and call it along
with almost all other flat device-tree parsers from early_init_devtree()
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
[mpe: Move #ifdefs into the header by providing pseries_probe_fw_features()]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Instead of punching a hole in the linear mapping, just use normal
cachable memory, and apply the flush sequence documented in the
CPC625 (aka U3) user manual.
This allows us to remove quite a bit of code related to the early
allocation of the DART and the hole in the linear mapping. We can
also get rid of the copy of the DART for suspend/resume as the
original memory can just be saved/restored now, as long as we
properly sync the caches.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
[mpe: Integrate dart_init() fix to return ENODEV when DART disabled]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
There is really no need to do them that early, early_setup() runs
before MMU is on, we should do the strict minimum there to get the
MMU going.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Make it part of early_setup() as we really want the feature fixups
to be applied before we turn on the MMU since they can have an impact
on the various assembly path related to MMU management and interrupts.
This makes 64-bit match what 32-bit does.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
32 and 64-bit do a similar set of calls early on, we move it all to
a single common function to make the boot code more readable.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
So the reserve_ebda_region() code has accumulated a number of
problems over the years that make it really difficult to read
and understand:
- The calculation of 'lowmem' and 'ebda_addr' is an unnecessarily
interleaved mess of first lowmem, then ebda_addr, then lowmem tweaks...
- 'lowmem' here means 'super low mem' - i.e. 16-bit addressable memory. In other
parts of the x86 code 'lowmem' means 32-bit addressable memory... This makes it
super confusing to read.
- It does not help at all that we have various memory range markers, half of which
are 'start of range', half of which are 'end of range' - but this crucial
property is not obvious in the naming at all ... gave me a headache trying to
understand all this.
- Also, the 'ebda_addr' name sucks: it highlights that it's an address (which is
obvious, all values here are addresses!), while it does not highlight that it's
the _start_ of the EBDA region ...
- 'BIOS_LOWMEM_KILOBYTES' says a lot of things, except that this is the only value
that is a pointer to a value, not a memory range address!
- The function name itself is a misnomer: it says 'reserve_ebda_region()' while
its main purpose is to reserve all the firmware ROM typically between 640K and
1MB, while the 'EBDA' part is only a small part of that ...
- Likewise, the paravirt quirk flag name 'ebda_search' is misleading as well: this
too should be about whether to reserve firmware areas in the paravirt case.
- In fact thinking about this as 'end of RAM' is confusing: what this function
*really* wants to reserve is firmware data and code areas! Once the thinking is
inverted from a mixed 'ram' and 'reserved firmware area' notion to a pure
'reserved area' notion everything becomes a lot clearer.
To improve all this rewrite the whole code (without changing the logic):
- Firstly invert the naming from 'lowmem end' to 'BIOS reserved area start'
and propagate this concept through all the variable names and constants.
BIOS_RAM_SIZE_KB_PTR // was: BIOS_LOWMEM_KILOBYTES
BIOS_START_MIN // was: INSANE_CUTOFF
ebda_start // was: ebda_addr
bios_start // was: lowmem
BIOS_START_MAX // was: LOWMEM_CAP
- Then clean up the name of the function itself by renaming it
to reserve_bios_regions() and renaming the ::ebda_search paravirt
flag to ::reserve_bios_regions.
- Fix up all the comments (fix typos), harmonize and simplify their
formulation and remove comments that become unnecessary due to
the much better naming all around.
Signed-off-by: Ingo Molnar <mingo@kernel.org>
The MIN_STACK_SIZE macro tries evaluate how much stack space needs
to be saved in the jprobes_stack array, sized at 128 bytes.
When using the IRQ stack, said macro can happily return up to
IRQ_STACK_SIZE, which is 16kB. Mayhem follows.
This patch fixes things by getting rid of the crazy macro and
limiting the copy to be at most the size of the jprobes_stack
array, no matter which stack we're on.
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
page should be calculated using physical address.
If platform uses non-trivial dma-to-phys memory translation,
dma_handle should be converted to physicval address before
calculation of page.
Failing to do so results in struct page * pointing to
wrong or non-existent memory.
Fixes: f2e3d55397ff ("ARC: dma: reintroduce platform specific dma<->phys")
Cc: stable@vger.kernel.org #4.6+
Signed-off-by: Vladimir Kondratiev <vladimir.kondratiev@intel.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
vcvtph2ps does not have an immediate operand, so remove the erroneous
'Ib' from its opcode map entry. Add vcvtph2ps to the perf tools new
instructions test to verify it.
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Acked-by: Ingo Molnar <mingo@kernel.org>
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: X86 ML <x86@kernel.org>
Link: http://lkml.kernel.org/r/1469003437-32706-2-git-send-email-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Monitored cached line may not wake up from mwait on certain
Goldmont based CPUs. This patch will avoid calling
current_set_polling_and_test() and thereby not set the TIF_ flag.
The result is that we'll always send IPIs for wakeups.
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Jacob Pan <jacob.jun.pan@linux.intel.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Arjan van de Ven <arjan@linux.intel.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Len Brown <lenb@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1468867270-18493-1-git-send-email-jacob.jun.pan@linux.intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Stepping with PSTATE.D=1 is bad news. The step won't generate a debug
exception and we'll likely walk off into random data structures. This
should never happen, but when it does, it's a PITA to debug. Add a
WARN_ON to shout if we realise this is about to take place.
Signed-off-by: Will Deacon <will.deacon@arm.com>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
The debug enable/disable macros are not used anywhere in the kernel, so
remove them from irqflags.h
Reported-by: Robin Murphy <robin.murphy@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
There is no need to explicitly clear the SS bit immediately before
setting it unconditionally.
Reported-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Clearing PSTATE.D is one of the requirements for generating a debug
exception. The arm64 booting protocol requires that PSTATE.D is set,
since many of the debug registers (for example, the hw_breakpoint
registers) are UNKNOWN out of reset and could potentially generate
spurious, fatal debug exceptions in early boot code if PSTATE.D was
clear. Once the debug registers have been safely initialised, PSTATE.D
is cleared, however this is currently broken for two reasons:
(1) The boot CPU clears PSTATE.D in a postcore_initcall and secondary
CPUs clear PSTATE.D in secondary_start_kernel. Since the initcall
runs after SMP (and the scheduler) have been initialised, there is
no guarantee that it is actually running on the boot CPU. In this
case, the boot CPU is left with PSTATE.D set and is not capable of
generating debug exceptions.
(2) In a preemptible kernel, we may explicitly schedule on the IRQ
return path to EL1. If an IRQ occurs with PSTATE.D set in the idle
thread, then we may schedule the kthread_init thread, run the
postcore_initcall to clear PSTATE.D and then context switch back
to the idle thread before returning from the IRQ. The exception
return path will then restore PSTATE.D from the stack, and set it
again.
This patch fixes the problem by moving the clearing of PSTATE.D earlier
to proc.S. This has the desirable effect of clearing it in one place for
all CPUs, long before we have to worry about the scheduler or any
exception handling. We ensure that the previous reset of MDSCR_EL1 has
completed before unmasking the exception, so that any spurious
exceptions resulting from UNKNOWN debug registers are not generated.
Without this patch applied, the kprobes selftests have been seen to fail
under KVM, where we end up attempting to step the OOL instruction buffer
with PSTATE.D set and therefore fail to complete the step.
Cc: <stable@vger.kernel.org>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Reported-by: Catalin Marinas <catalin.marinas@arm.com>
Tested-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Tested-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
We currently define OBJCOPYFLAGS in the top-level arm64 Makefile, and
thus these flags will be passed to all uses of objcopy, kernel-wide, for
which they are not explicitly overridden. The flags we set are intended
for converting vmlinux (and ELF) into Image (a raw binary), and thus the
flags chosen are problematic for some other uses which do not expect a
raw binary result, e.g. the upcoming lkdtm rodata test:
http://www.openwall.com/lists/kernel-hardening/2016/06/08/2
This patch localises the objcopy flags such that they are only used for
the vmlinux -> Image conversion.
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Acked-by: Kees Cook <keescook@chromium.org>
Tested-by: Laura Abbott <labbott@redhat.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
...and do not confuse source navigation tools ;)
Signed-off-by: Vladimir Murzin <vladimir.murzin@arm.com>
Acked-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
