To avoid issues with the /proc/kcore code getting confused about the
kernels block mappings in the VMALLOC region, enable the existing
facility that describes the [_text, _end) interval as a separate
KCORE_TEXT region, which supersedes the KCORE_VMALLOC region that
it intersects with on arm64.
Reported-by: NTan Xiaojun <tanxiaojun@huawei.com>
Tested-by: NTan Xiaojun <tanxiaojun@huawei.com>
Tested-by: NMark Rutland <mark.rutland@arm.com>
Acked-by: NMark Rutland <mark.rutland@arm.com>
Reviewed-by: NLaura Abbott <labbott@redhat.com>
Reviewed-by: NJiri Olsa <jolsa@kernel.org>
Signed-off-by: NArd Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: NWill Deacon <will.deacon@arm.com>

The kernel watchdog is a great debugging tool for finding tasks that
consume a disproportionate amount of CPU time in contiguous chunks. One
can imagine building a similar watchdog for arbitrary driver threads
using save_stack_trace_tsk() and print_stack_trace(). However, this is
not viable for dynamically loaded driver modules on ARM platforms
because save_stack_trace_tsk() is not exported for those architectures.
Export save_stack_trace_tsk() for the ARM64 architecture to align with
x86 and support various debugging use cases such as arbitrary driver
thread watchdog timers.
Signed-off-by: NDustin Brown <dustinb@codeaurora.org>
Signed-off-by: NWill Deacon <will.deacon@arm.com>

ACPI IORT is an ACPI addendum to describe the connection topology of
devices with IOMMUs and interrupt controllers on ARM64 ACPI systems.

Currently the ACPI IORT Kbuild symbol is selected whenever the Kbuild
symbol ARM_GIC_V3_ITS is enabled, which in turn is selected by ARM64
Kbuild defaults. This makes the logic behind ACPI_IORT selection a bit
twisted and not easy to follow. On ARM64 systems enabling ACPI the
kbuild symbol ACPI_IORT should always be selected in that it is a kernel
layer provided to the ARM64 arch code to parse and enable ACPI firmware
bindings.

Make the ACPI_IORT selection explicit in ARM64 Kbuild and remove the
selection from ARM_GIC_V3_ITS entry, making the ACPI_IORT selection
logic clearer to follow.
Acked-by: NHanjun Guo <hanjun.guo@linaro.org>
Signed-off-by: NLorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Hanjun Guo <hanjun.guo@linaro.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: NWill Deacon <will.deacon@arm.com>

The current null-pointer check in __dma_alloc_coherent and
__dma_free_coherent is not needed anymore since the
__dma_alloc/__dma_free functions won't be called if !dev (dummy ops will
be called instead).
Reviewed-by: NCatalin Marinas <catalin.marinas@arm.com>
Signed-off-by: NOlav Haugan <ohaugan@codeaurora.org>
Signed-off-by: NWill Deacon <will.deacon@arm.com>

Declare ARCH_SUPPORTS_MEMORY_FAILURE, as arm64 does support
memory failure recovery attempt.
Signed-off-by: NJonathan (Zhixiong) Zhang <zjzhang@codeaurora.org>
Signed-off-by: NTyler Baicar <tbaicar@codeaurora.org>
(Dropped changes to ACPI APEI Kconfig and updated commit log)
Signed-off-by: NPunit Agrawal <punit.agrawal@arm.com>
Acked-by: NSteve Capper <steve.capper@arm.com>
Tested-by: NManoj Iyer <manoj.iyer@canonical.com>
Signed-off-by: NWill Deacon <will.deacon@arm.com>

Re-organise the perf accounting for fault handling in preparation for
enabling handling of hardware poison faults in subsequent commits. The
change updates perf accounting to be inline with the behaviour on
x86.

With this update, the perf fault accounting -

  * Always report PERF_COUNT_SW_PAGE_FAULTS

  * Doesn't report anything else for VM_FAULT_ERROR (which includes
    hwpoison faults)

  * Reports PERF_COUNT_SW_PAGE_FAULTS_MAJ if it's a major
    fault (indicated by VM_FAULT_MAJOR)

  * Otherwise, reports PERF_COUNT_SW_PAGE_FAULTS_MIN
Signed-off-by: NPunit Agrawal <punit.agrawal@arm.com>
Signed-off-by: NWill Deacon <will.deacon@arm.com>

Add VM_FAULT_HWPOISON[_LARGE] handling to the arm64 page fault
handler. Handling of VM_FAULT_HWPOISON[_LARGE] is very similar
to VM_FAULT_OOM, the only difference is that a different si_code
(BUS_MCEERR_AR) is passed to user space and si_addr_lsb field is
initialized.
Signed-off-by: NJonathan (Zhixiong) Zhang <zjzhang@codeaurora.org>
Signed-off-by: NTyler Baicar <tbaicar@codeaurora.org>
(fix new __do_user_fault call-site)
Signed-off-by: NPunit Agrawal <punit.agrawal@arm.com>
Acked-by: NSteve Capper <steve.capper@arm.com>
Tested-by: NManoj Iyer <manoj.iyer@canonical.com>
Signed-off-by: NWill Deacon <will.deacon@arm.com>

When memory failure is enabled, a poisoned hugepage pte is marked as a
swap entry. huge_pte_offset() does not return the poisoned page table
entries when it encounters PUD/PMD hugepages.

This behaviour of huge_pte_offset() leads to error such as below when
munmap is called on poisoned hugepages.

[  344.165544] mm/pgtable-generic.c:33: bad pmd 000000083af00074.

Fix huge_pte_offset() to return the poisoned pte which is then
appropriately handled by the generic layer code.
Signed-off-by: NPunit Agrawal <punit.agrawal@arm.com>
Acked-by: NSteve Capper <steve.capper@arm.com>
Reviewed-by: NCatalin Marinas <catalin.marinas@arm.com>
Cc: David Woods <dwoods@mellanox.com>
Tested-by: NManoj Iyer <manoj.iyer@canonical.com>
Signed-off-by: NWill Deacon <will.deacon@arm.com>

When CONFIG_MODULES is disabled, we cannot dereference a module pointer:

arch/arm64/kernel/ftrace.c: In function 'ftrace_make_call':
arch/arm64/kernel/ftrace.c:107:36: error: dereferencing pointer to incomplete type 'struct module'
   trampoline = (unsigned long *)mod->arch.ftrace_trampoline;

Also, the within_module() function is not defined:

arch/arm64/kernel/ftrace.c: In function 'ftrace_make_nop':
arch/arm64/kernel/ftrace.c:171:8: error: implicit declaration of function 'within_module'; did you mean 'init_module'? [-Werror=implicit-function-declaration]

This addresses both by adding replacing the IS_ENABLED(CONFIG_ARM64_MODULE_PLTS)
checks with #ifdef versions.

Fixes: e71a4e1b ("arm64: ftrace: add support for far branches to dynamic ftrace")
Reported-by: NArnd Bergmann <arnd@arndb.de>
Acked-by: NArd Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: NWill Deacon <will.deacon@arm.com>

Whilst debugging a remote crash, I noticed that show_pte is unhelpful
when it comes to describing the structure of the page table being walked.
This is easily fixed by printing out the page table (swapper vs user),
page size and virtual address size when displaying the PGD address.
Acked-by: NMark Rutland <mark.rutland@arm.com>
Signed-off-by: NWill Deacon <will.deacon@arm.com>

Print out the name of the file associated with the vma that faulted.
This is usually the executable or shared library name. We already print
out the task name, but also printing the library name is useful for
pinpointing bugs to libraries.

Also print the base address and size of the vma, which together with the
PC (printed by __show_regs) gives the offset into the library.

Fault prints now look like:
test[2361]: unhandled level 2 translation fault (11) at 0x00000012, esr 0x92000006, in libfoo.so[ffffa0145000+1000]

This is already done on x86, for more details see commit 03252919
("x86: print which shared library/executable faulted in segfault etc.
messages v3").
Acked-by: NMark Rutland <mark.rutland@arm.com>
Signed-off-by: NKristina Martsenko <kristina.martsenko@arm.com>
Signed-off-by: NWill Deacon <will.deacon@arm.com>

When we take a fault from EL0 that can't be handled, we print out the
page table entries associated with the faulting address. This allows
userspace to print out any current page table entries, including kernel
(TTBR1) entries. Exposing kernel mappings like this could pose a
security risk, so don't print out page table information on EL0 faults.
(But still print it out for EL1 faults.) This also follows the same
behaviour as x86, printing out page table entries on kernel mode faults
but not user mode faults.
Acked-by: NMark Rutland <mark.rutland@arm.com>
Signed-off-by: NKristina Martsenko <kristina.martsenko@arm.com>
Signed-off-by: NWill Deacon <will.deacon@arm.com>

When we take a fault that can't be handled, we print out the page table
entries associated with the faulting address. In some cases we currently
print out the wrong entries. For a faulting TTBR1 address, we sometimes
print out TTBR0 table entries instead, and for a faulting TTBR0 address
we sometimes print out TTBR1 table entries. Fix this by choosing the
tables based on the faulting address.
Acked-by: NMark Rutland <mark.rutland@arm.com>
Signed-off-by: NKristina Martsenko <kristina.martsenko@arm.com>
[will: zero-extend addrs to 64-bit, don't walk swapper w/ TTBR0 addr]
Signed-off-by: NWill Deacon <will.deacon@arm.com>

Currently, dynamic ftrace support in the arm64 kernel assumes that all
core kernel code is within range of ordinary branch instructions that
occur in module code, which is usually the case, but is no longer
guaranteed now that we have support for module PLTs and address space
randomization.

Since on arm64, all patching of branch instructions involves function
calls to the same entry point [ftrace_caller()], we can emit the modules
with a trampoline that has unlimited range, and patch both the trampoline
itself and the branch instruction to redirect the call via the trampoline.
Signed-off-by: NArd Biesheuvel <ard.biesheuvel@linaro.org>
[will: minor clarification to smp_wmb() comment]
Signed-off-by: NWill Deacon <will.deacon@arm.com>

When turning branch instructions into NOPs, we attempt to validate the
action by comparing the old value at the call site with the opcode of
a direct relative branch instruction pointing at the old target.

However, these call sites are statically initialized to call _mcount(),
and may be redirected via a PLT entry if the module is loaded far away
from the kernel text, leading to false negatives and spurious errors.

So skip the validation if CONFIG_ARM64_MODULE_PLTS is configured.
Signed-off-by: NArd Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: NWill Deacon <will.deacon@arm.com>

Adjust vdso_{start|end} to be char arrays to avoid compile-time analysis
that flags "too large" memcmp() calls with CONFIG_FORTIFY_SOURCE.

Cc: Jisheng Zhang <jszhang@marvell.com>
Acked-by: NCatalin Marinas <catalin.marinas@arm.com>
Suggested-by: NMark Rutland <mark.rutland@arm.com>
Signed-off-by: NKees Cook <keescook@chromium.org>
Signed-off-by: NWill Deacon <will.deacon@arm.com>

Commit 3fde2999 ("arm64: cpufeature: Don't dump useless backtrace on
CPU_OUT_OF_SPEC") changed the cpufeature detection code to use add_taint
instead of WARN_TAINT_ONCE when detecting a heterogeneous system with
mismatched feature support. Unfortunately, this resulted in all systems
getting the taint, regardless of any feature mismatch.

This patch fixes the problem by conditionalising the taint on detecting
a feature mismatch.
Acked-by: NMark Rutland <mark.rutland@arm.com>
Reported-by: NHeiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: NWill Deacon <will.deacon@arm.com>

When running lscpu on an AArch64 system that has SMBIOS version 2.0
tables, it will segfault in the following way:

  Unable to handle kernel paging request at virtual address ffff8000bfff0000
  pgd = ffff8000f9615000
  [ffff8000bfff0000] *pgd=0000000000000000
  Internal error: Oops: 96000007 [#1] PREEMPT SMP
  Modules linked in:
  CPU: 0 PID: 1284 Comm: lscpu Not tainted 4.11.0-rc3+ #103
  Hardware name: QEMU QEMU Virtual Machine, BIOS 0.0.0 02/06/2015
  task: ffff8000fa78e800 task.stack: ffff8000f9780000
  PC is at __arch_copy_to_user+0x90/0x220
  LR is at read_mem+0xcc/0x140

This is caused by the fact that lspci issues a read() on /dev/mem at the
offset where it expects to find the SMBIOS structure array. However, this
region is classified as EFI_RUNTIME_SERVICE_DATA (as per the UEFI spec),
and so it is omitted from the linear mapping.

So let's restrict /dev/mem read/write access to those areas that are
covered by the linear region.
Reported-by: NAlexander Graf <agraf@suse.de>
Fixes: 4dffbfc4 ("arm64/efi: mark UEFI reserved regions as MEMBLOCK_NOMAP")
Signed-off-by: NArd Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: NWill Deacon <will.deacon@arm.com>

PCI core requires the NUMA node for the struct pci_host_bridge.dev to
be set by using the pcibus_to_node(struct pci_bus*) API, that on ARM64
systems relies on the struct pci_host_bridge->bus.dev NUMA node.

The struct pci_host_bridge.dev NUMA node is then propagated through
the PCI device hierarchy as PCI devices (and bridges) are enumerated
under it.

Therefore, in order to set-up the PCI NUMA hierarchy appropriately, the
struct pci_host_bridge->bus.dev NUMA node must be set before core
code calls pcibus_to_node(struct pci_bus*) on it so that PCI core can
retrieve the NUMA node for the struct pci_host_bridge.dev device and can
propagate it through the PCI bus tree.

On ARM64 ACPI based systems the struct pci_host_bridge->bus.dev NUMA
node can be set-up in pcibios_root_bridge_prepare() by parsing the root
bridge ACPI device firmware binding.

Add code to the pcibios_root_bridge_prepare() that, when booting with
ACPI, parse the root bridge ACPI device companion NUMA binding and set
the corresponding struct pci_host_bridge->bus.dev NUMA node
appropriately.

Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Reviewed-by: NRobert Richter <rrichter@cavium.com>
Tested-by: NRobert Richter <rrichter@cavium.com>
Signed-off-by: NLorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Signed-off-by: NWill Deacon <will.deacon@arm.com>

FUTEX_OP_OPARG_SHIFT instructs the futex code to treat the 12-bit oparg
field as a shift value, potentially leading to a left shift value that
is negative or with an absolute value that is significantly larger then
the size of the type. UBSAN chokes with:

================================================================================
UBSAN: Undefined behaviour in ./arch/arm64/include/asm/futex.h:60:13
shift exponent -1 is negative
CPU: 1 PID: 1449 Comm: syz-executor0 Not tainted 4.11.0-rc4-00005-g977eb52-dirty #11
Hardware name: linux,dummy-virt (DT)
Call trace:
[<ffff200008094778>] dump_backtrace+0x0/0x538 arch/arm64/kernel/traps.c:73
[<ffff200008094cd0>] show_stack+0x20/0x30 arch/arm64/kernel/traps.c:228
[<ffff200008c194a8>] __dump_stack lib/dump_stack.c:16 [inline]
[<ffff200008c194a8>] dump_stack+0x120/0x188 lib/dump_stack.c:52
[<ffff200008cc24b8>] ubsan_epilogue+0x18/0x98 lib/ubsan.c:164
[<ffff200008cc3098>] __ubsan_handle_shift_out_of_bounds+0x250/0x294 lib/ubsan.c:421
[<ffff20000832002c>] futex_atomic_op_inuser arch/arm64/include/asm/futex.h:60 [inline]
[<ffff20000832002c>] futex_wake_op kernel/futex.c:1489 [inline]
[<ffff20000832002c>] do_futex+0x137c/0x1740 kernel/futex.c:3231
[<ffff200008320504>] SYSC_futex kernel/futex.c:3281 [inline]
[<ffff200008320504>] SyS_futex+0x114/0x268 kernel/futex.c:3249
[<ffff200008084770>] el0_svc_naked+0x24/0x28
================================================================================
syz-executor1 uses obsolete (PF_INET,SOCK_PACKET)
sock: process `syz-executor0' is using obsolete setsockopt SO_BSDCOMPAT

This patch attempts to fix some of this by:

  * Making encoded_op an unsigned type, so we can shift it left even if
    the top bit is set.

  * Casting to signed prior to shifting right when extracting oparg
    and cmparg

  * Consider only the bottom 5 bits of oparg when using it as a left-shift
    value.

Whilst I think this catches all of the issues, I'd much prefer to remove
this stuff, as I think it's unused and the bugs are copy-pasted between
a bunch of architectures.
Reviewed-by: NRobin Murphy <robin.murphy@arm.com>
Signed-off-by: NWill Deacon <will.deacon@arm.com>

It's useless to print machine name and setup arch-specific system
identifiers if of_flat_dt_get_machine_name() return NULL, especially
when ACPI-based boot.
Reviewed-by: NGeert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: NKefeng Wang <wangkefeng.wang@huawei.com>
Signed-off-by: NWill Deacon <will.deacon@arm.com>

Unfortunately, it turns out that mismatched CPU features in big.LITTLE
systems are starting to appear in the wild. Whilst we should continue to
taint the kernel with CPU_OUT_OF_SPEC for features that differ in ways
that we can't fix up, dumping a useless backtrace out of the cpufeature
code is pointless and irritating.

This patch removes the backtrace from the taint.
Signed-off-by: NMark Rutland <mark.rutland@arm.com>
Signed-off-by: NWill Deacon <will.deacon@arm.com>

arm64's mm/mmu.c uses vm_area_add_early, struct vm_area and other
definitions  but relies on implict inclusion of linux/vmalloc.h which
means that changes in other headers could break the build. Thus, add an
explicit include.
Acked-by: NArd Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: NTobias Klauser <tklauser@distanz.ch>
Signed-off-by: NWill Deacon <will.deacon@arm.com>

Generic code expects show_regs() to dump the stack, but arm64's
show_regs() does not. This makes it hard to debug softlockups and
other issues that result in show_regs() being called.

This patch updates arm64's show_regs() to dump the stack, as common
code expects.
Acked-by: NMark Rutland <mark.rutland@arm.com>
Signed-off-by: NKefeng Wang <wangkefeng.wang@huawei.com>
[will: folded in bug_handler fix from mrutland]
Signed-off-by: NWill Deacon <will.deacon@arm.com>

Generic code expects show_regs() to also dump the stack, but arm64's
show_reg() does not do this. Some arm64 callers of show_regs() *only*
want the registers dumped, without the stack.

To enable generic code to work as expected, we need to make
show_regs() dump the stack. Where we only want the registers dumped,
we must use __show_regs().

This patch updates code to use __show_regs() where only registers are
desired. A subsequent patch will modify show_regs().
Acked-by: NMark Rutland <mark.rutland@arm.com>
Signed-off-by: NKefeng Wang <wangkefeng.wang@huawei.com>
Signed-off-by: NWill Deacon <will.deacon@arm.com>

Like arch/arm/, we inherit the READ_IMPLIES_EXEC personality flag across
fork(). This is undesirable for a number of reasons:

  * ELF files that don't require executable stack can end up with it
    anyway

  * We end up performing un-necessary I-cache maintenance when mapping
    what should be non-executable pages

  * Restricting what is executable is generally desirable when defending
    against overflow attacks

This patch clears the personality flag when setting up the personality for
newly spwaned native tasks. Given that semi-recent AArch64 toolchains emit
a non-executable PT_GNU_STACK header, userspace applications can already
not rely on READ_IMPLIES_EXEC so shouldn't be adversely affected by this
change.

Cc: <stable@vger.kernel.org>
Reported-by: NPeter Maydell <peter.maydell@linaro.org>
Signed-off-by: NDong Bo <dongbo4@huawei.com>
[will: added comment to compat code, rewrote commit message]
Signed-off-by: NWill Deacon <will.deacon@arm.com>

ftrace use module_alloc() to allocate trampoline pages. The mapping of
module_alloc() is RWX, which makes sense as the memory is written to right
after allocation. But nothing makes these pages RO after writing to them.

Add proper set_memory_rw/ro() calls to protect the trampolines after
modification.

Link: http://lkml.kernel.org/r/alpine.DEB.2.20.1705251056410.1862@nanosSigned-off-by: NThomas Gleixner <tglx@linutronix.de>
Signed-off-by: NSteven Rostedt (VMware) <rostedt@goodmis.org>

With function tracing starting in early bootup and having its trampoline
pages being read only, a bug triggered with the following:

kernel BUG at arch/x86/mm/pageattr.c:189!
invalid opcode: 0000 [#1] SMP
Modules linked in:
CPU: 0 PID: 0 Comm: swapper Not tainted 4.12.0-rc2-test+ #3
Hardware name: MSI MS-7823/CSM-H87M-G43 (MS-7823), BIOS V1.6 02/22/2014
task: ffffffffb4222500 task.stack: ffffffffb4200000
RIP: 0010:change_page_attr_set_clr+0x269/0x302
RSP: 0000:ffffffffb4203c88 EFLAGS: 00010046
RAX: 0000000000000046 RBX: 0000000000000000 RCX: 00000001b6000000
RDX: ffffffffb4203d40 RSI: 0000000000000000 RDI: ffffffffb4240d60
RBP: ffffffffb4203d18 R08: 00000001b6000000 R09: 0000000000000001
R10: ffffffffb4203aa8 R11: 0000000000000003 R12: ffffffffc029b000
R13: ffffffffb4203d40 R14: 0000000000000001 R15: 0000000000000000
FS:  0000000000000000(0000) GS:ffff9a639ea00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffff9a636b384000 CR3: 00000001ea21d000 CR4: 00000000000406b0
Call Trace:
 change_page_attr_clear+0x1f/0x21
 set_memory_ro+0x1e/0x20
 arch_ftrace_update_trampoline+0x207/0x21c
 ? ftrace_caller+0x64/0x64
 ? 0xffffffffc029b000
 ftrace_startup+0xf4/0x198
 register_ftrace_function+0x26/0x3c
 function_trace_init+0x5e/0x73
 tracer_init+0x1e/0x23
 tracing_set_tracer+0x127/0x15a
 register_tracer+0x19b/0x1bc
 init_function_trace+0x90/0x92
 early_trace_init+0x236/0x2b3
 start_kernel+0x200/0x3f5
 x86_64_start_reservations+0x29/0x2b
 x86_64_start_kernel+0x17c/0x18f
 secondary_startup_64+0x9f/0x9f
 ? secondary_startup_64+0x9f/0x9f

Interrupts should not be enabled at this early in the boot process. It is
also fine to leave interrupts enabled during this time as there's only one
CPU running, and on_each_cpu() means to only run on the current CPU.

If early_boot_irqs_disabled is set, it is safe to run cpu_flush_range() with
interrupts disabled. Don't trigger a BUG_ON() in that case.

Link: http://lkml.kernel.org/r/20170526093717.0be3b849@gandalf.local.homeSuggested-by: NThomas Gleixner <tglx@linutronix.de>
Signed-off-by: NSteven Rostedt (VMware) <rostedt@goodmis.org>

Fix kprobes to set(recover) RWX bits correctly on trampoline
buffer before releasing it. Releasing readonly page to
module_memfree() crash the kernel.

Without this fix, if kprobes user register a bunch of kprobes
in function body (since kprobes on function entry usually
use ftrace) and unregister it, kernel hits a BUG and crash.

Link: http://lkml.kernel.org/r/149570868652.3518.14120169373590420503.stgit@devboxSigned-off-by: NMasami Hiramatsu <mhiramat@kernel.org>
Fixes: d0381c81 ("kprobes/x86: Set kprobes pages read-only")
Signed-off-by: NSteven Rostedt (VMware) <rostedt@goodmis.org>

This ensures that adjustments to x86_platform done by the hypervisor
setup is already respected by this simple calibration.

The current user of this, introduced by 1b5aeebf ("x86/earlyprintk:
Add support for earlyprintk via USB3 debug port"), comes much later
into play.

Fixes: dd759d93 ("x86/timers: Add simple udelay calibration")
Signed-off-by: NJan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Acked-by: NLu Baolu <baolu.lu@linux.intel.com>
Link: http://lkml.kernel.org/r/5e89fe60-aab3-2c1c-aba8-32f8ad376189@siemens.com

Providing "scv" support to userspace requires kernel support, so it
must be advertised as independently to the base ISA 3 instruction set.

The darn instruction relies on firmware enablement, so it has been
decided to split this out from the core ISA 3 feature as well.
Signed-off-by: NNicholas Piggin <npiggin@gmail.com>
Acked-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>

Commit ac29c640 ("powerpc/mm: Replace _PAGE_USER with
_PAGE_PRIVILEGED") swapped _PAGE_USER for _PAGE_PRIVILEGED, and
introduced check_pte_access() which denied kernel access to
non-_PAGE_PRIVILEGED pages.

However, it didn't add _PAGE_PRIVILEGED to the hash fault handler
for spufs' kernel accesses, so the DMAs required to establish SPE
memory no longer work.

This change adds _PAGE_PRIVILEGED to the hash fault handler for
kernel accesses.

Fixes: ac29c640 ("powerpc/mm: Replace _PAGE_USER with _PAGE_PRIVILEGED")
Cc: stable@vger.kernel.org # v4.7+
Signed-off-by: NJeremy Kerr <jk@ozlabs.org>
Reported-by: NSombat Tragolgosol <sombat3960@gmail.com>
Reviewed-by: NAneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>

Currently if you disable CONFIG_PPC_RADIX_MMU you'll crash on boot on
a P9. This is because we still set MMU_FTR_TYPE_RADIX via
ibm,pa-features and MMU_FTR_TYPE_RADIX is what's used for code patching
in much of the asm code (ie. slb_miss_realmode)

This patch fixes the problem by stopping MMU_FTR_TYPE_RADIX from being
set from ibm.pa-features.

We may eventually end up removing the CONFIG_PPC_RADIX_MMU option
completely but until then this fixes the issue.

Fixes: 17a3dd2f ("powerpc/mm/radix: Use firmware feature to enable Radix MMU")
Cc: stable@vger.kernel.org # v4.7+
Signed-off-by: NMichael Neuling <mikey@neuling.org>
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>

opal_npu_destroy_context() should be called with the NPU PHB, not the
PCIe PHB.

Fixes: 1ab66d1f ("powerpc/powernv: Introduce address translation services for Nvlink2")
Signed-off-by: NAlistair Popple <alistair@popple.id.au>
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>

In the current form of the code, if a->replacementlen is 0, the reference
to *insnbuf for comparison touches potentially garbage memory. While it
doesn't affect the execution flow due to the subsequent a->replacementlen
comparison, it is (rightly) detected as use of uninitialized memory by a
runtime instrumentation currently under my development, and could be
detected as such by other tools in the future, too (e.g. KMSAN).

Fix the "false-positive" by reordering the conditions to first check the
replacement instruction length before referencing specific opcode bytes.
Signed-off-by: NMateusz Jurczyk <mjurczyk@google.com>
Reviewed-by: NBorislav Petkov <bp@suse.de>
Cc: Andy Lutomirski <luto@kernel.org>
Link: http://lkml.kernel.org/r/20170524135500.27223-1-mjurczyk@google.comSigned-off-by: NThomas Gleixner <tglx@linutronix.de>

In the file arch/x86/mm/pat.c, there's a '__pat_enabled' variable. The
variable is set to 1 by default and the function pat_init() sets
__pat_enabled to 0 if the CPU doesn't support PAT.

However, on AMD K6-3 CPUs, the processor initialization code never calls
pat_init() and so __pat_enabled stays 1 and the function pat_enabled()
returns true, even though the K6-3 CPU doesn't support PAT.

The result of this bug is that a kernel warning is produced when attempting to
start the Xserver and the Xserver doesn't start (fork() returns ENOMEM).
Another symptom of this bug is that the framebuffer driver doesn't set the
K6-3 MTRR registers:

  x86/PAT: Xorg:3891 map pfn expected mapping type uncached-minus for [mem 0xe4000000-0xe5ffffff], got write-combining
  ------------[ cut here ]------------
  WARNING: CPU: 0 PID: 3891 at arch/x86/mm/pat.c:1020 untrack_pfn+0x5c/0x9f
  ...
  x86/PAT: Xorg:3891 map pfn expected mapping type uncached-minus for [mem 0xe4000000-0xe5ffffff], got write-combining

To fix the bug change pat_enabled() so that it returns true only if PAT
initialization was actually done.

Also, I changed boot_cpu_has(X86_FEATURE_PAT) to
this_cpu_has(X86_FEATURE_PAT) in pat_ap_init(), so that we check the PAT
feature on the processor that is being initialized.
Signed-off-by: NMikulas Patocka <mpatocka@redhat.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andy Lutomirski <luto@kernel.org>
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: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Luis R. Rodriguez <mcgrof@suse.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Toshi Kani <toshi.kani@hp.com>
Cc: stable@vger.kernel.org # v4.2+
Link: http://lkml.kernel.org/r/alpine.LRH.2.02.1704181501450.26399@file01.intranet.prod.int.rdu2.redhat.comSigned-off-by: NIngo Molnar <mingo@kernel.org>

Signed-off-by: NBenjamin Peterson <bp@benjamin.pe>
Acked-by: NThomas Gleixner <tglx@linutronix.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Fixes: 9919cba7 ("watchdog: Update documentation")
Link: http://lkml.kernel.org/r/20170521002016.13258-1-bp@benjamin.peSigned-off-by: NIngo Molnar <mingo@kernel.org>

At least Make 3.82 dislikes the tab in front of the $(warning) function:

  arch/x86/Makefile:162: *** recipe commences before first target.  Stop.

Let's be gentle.
Signed-off-by: NJan Kiszka <jan.kiszka@siemens.com>
Acked-by: NThomas Gleixner <tglx@linutronix.de>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1944fcd8-e3df-d1f7-c0e4-60aeb1917a24@siemens.comSigned-off-by: NIngo Molnar <mingo@kernel.org>

Dave Jones and Steven Rostedt reported unwinder warnings like the
following:

  WARNING: kernel stack frame pointer at ffff8800bda0ff30 in sshd:1090 has bad value 000055b32abf1fa8

In both cases, the unwinder was attempting to unwind from an ftrace
handler into entry code.  The callchain was something like:

  syscall entry code
    C function
      ftrace handler
        save_stack_trace()

The problem is that the unwinder's end-of-stack logic gets confused by
the way ftrace lays out the stack frame (with fentry enabled).

I was able to recreate this warning with:

  echo call_usermodehelper_exec_async:stacktrace > /sys/kernel/debug/tracing/set_ftrace_filter
  (exit login session)

I considered fixing this by changing the ftrace code to rewrite the
stack to make the unwinder happy.  But that seemed too intrusive after I
implemented it.  Instead, just add another check to the unwinder's
end-of-stack logic to detect this special case.

Side note: We could probably get rid of these end-of-stack checks by
encoding the frame pointer for syscall entry just like we do for
interrupt entry.  That would be simpler, but it would also be a lot more
intrusive since it would slightly affect the performance of every
syscall.
Reported-by: NDave Jones <davej@codemonkey.org.uk>
Reported-by: NSteven Rostedt <rostedt@goodmis.org>
Signed-off-by: NJosh Poimboeuf <jpoimboe@redhat.com>
Acked-by: NThomas Gleixner <tglx@linutronix.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Petr Mladek <pmladek@suse.com>
Cc: live-patching@vger.kernel.org
Fixes: c32c47c6 ("x86/unwind: Warn on bad frame pointer")
Link: http://lkml.kernel.org/r/671ba22fbc0156b8f7e0cfa5ab2a795e08bc37e1.1495553739.git.jpoimboe@redhat.comSigned-off-by: NIngo Molnar <mingo@kernel.org>

Petr Mladek reported the following warning when loading the livepatch
sample module:

  WARNING: CPU: 1 PID: 3699 at arch/x86/kernel/stacktrace.c:132 save_stack_trace_tsk_reliable+0x133/0x1a0
  ...
  Call Trace:
   __schedule+0x273/0x820
   schedule+0x36/0x80
   kthreadd+0x305/0x310
   ? kthread_create_on_cpu+0x80/0x80
   ? icmp_echo.part.32+0x50/0x50
   ret_from_fork+0x2c/0x40

That warning means the end of the stack is no longer recognized as such
for newly forked tasks.  The problem was introduced with the following
commit:

  ff3f7e24 ("x86/entry: Fix the end of the stack for newly forked tasks")

... which was completely misguided.  It only partially fixed the
reported issue, and it introduced another bug in the process.  None of
the other entry code saves the frame pointer before calling into C code,
so it doesn't make sense for ret_from_fork to do so either.

Contrary to what I originally thought, the original issue wasn't related
to newly forked tasks.  It was actually related to ftrace.  When entry
code calls into a function which then calls into an ftrace handler, the
stack frame looks different than normal.

The original issue will be fixed in the unwinder, in a subsequent patch.
Reported-by: NPetr Mladek <pmladek@suse.com>
Signed-off-by: NJosh Poimboeuf <jpoimboe@redhat.com>
Acked-by: NThomas Gleixner <tglx@linutronix.de>
Cc: Dave Jones <davej@codemonkey.org.uk>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: live-patching@vger.kernel.org
Fixes: ff3f7e24 ("x86/entry: Fix the end of the stack for newly forked tasks")
Link: http://lkml.kernel.org/r/f350760f7e82f0750c8d1dd093456eb212751caa.1495553739.git.jpoimboe@redhat.comSigned-off-by: NIngo Molnar <mingo@kernel.org>