The csum_partial_copy_generic() function saves the PowerPC non-volatile
r14, r15, and r16 registers for the main checksum-and-copy loop.
Unfortunately, it fails to restore them upon error exit from this loop,
which results in silent corruption of these registers in the presumably
rare event of an access exception within that loop.
This commit therefore restores these register on error exit from the loop.
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Signed-off-by: Anton Blanchard <anton@samba.org>
Cc: stable@vger.kernel.org
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
The csum_partial_copy_generic() uses register r7 to adjust the remaining
bytes to process. Unfortunately, r7 also holds a parameter, namely the
address of the flag to set in case of access exceptions while reading
the source buffer. Lacking a quantum implementation of PowerPC, this
commit instead uses register r9 to do the adjusting, leaving r7's
pointer uncorrupted.
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Signed-off-by: Anton Blanchard <anton@samba.org>
Cc: stable@vger.kernel.org
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Previous commit 46723bfa540... introduced a new config option
HAVE_BOOTMEM_INFO_NODE that ended up breaking memory hot-remove for ppc
when sparse vmemmap is not defined.
This patch defines HAVE_BOOTMEM_INFO_NODE for ppc and adds the call to
register_page_bootmem_info_node. Without this we get a BUG_ON for memory
hot remove in put_page_bootmem().
This also adds a stub for register_page_bootmem_memmap to allow ppc to build
with sparse vmemmap defined. Leaving this as a stub is fine since the same
vmemmap addresses are also handled in vmemmap_populate and as such are
properly mapped.
Signed-off-by: Nathan Fontenot <nfont@linux.vnet.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
CC: <stable@vger.kernel.org> [v3.9+]
Pull Xen fixes from Konrad Rzeszutek Wilk:
"Bug-fixes and one update to the kernel-paramters.txt documentation.
- Fix PV spinlocks triggering jump_label code bug
- Remove extraneous code in the tpm front driver
- Fix ballooning out of pages when non-preemptible
- Fix deadlock when using a 32-bit initial domain with large amount
of memory
- Add xen_nopvpsin parameter to the documentation"
* tag 'stable/for-linus-3.12-rc2-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip:
xen/spinlock: Document the xen_nopvspin parameter.
xen/p2m: check MFN is in range before using the m2p table
xen/balloon: don't alloc page while non-preemptible
xen: Do not enable spinlocks before jump_label_init() has executed
tpm: xen-tpmfront: Remove the locality sysfs attribute
tpm: xen-tpmfront: Fix default durations
Pull MIPS fixes from Ralf Baechle:
- Fix a comment
- A small cleanup the main purpose of which is to work around an
internal compiler error bug in certain Codesource toolchains.
* git://git.linux-mips.org/pub/scm/ralf/upstream-linus:
MIPS: mm: Move some checks out of 'for' loop in DMA operations
MIPS: cpu-features.h: s/MIPS53/MIPS64/
Pull powerpc fixes from Ben Herrenschmidt:
"Here are a few things for -rc2, this time it's all written by me so it
can only be perfect .... right ? :)
So we have the fix to call irq_enter/exit on the irq stack we've been
discussing, plus a cleanup on top to remove an unused (and broken)
stack limit tracking feature (well, make it 32-bit only in fact where
it is used and works properly).
Then we have two things that I wrote over the last couple of days and
made the executive decision to include just because I can (and I'm
sure you won't object .... right ?).
They fix a couple of annoying and long standing "issues":
- We had separate zImages for when booting via Open Firmware vs.
booting via a flat device-tree, while it's trivial to make one that
deals with both
- We wasted a ton of cycles spinning secondary CPUs uselessly at boot
instead of starting them when needed on pseries, thus contributing
significantly to global warming"
* 'merge' of git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc:
powerpc/pseries: Do not start secondaries in Open Firmware
powerpc/zImage: make the "OF" wrapper support ePAPR boot
powerpc: Remove ksp_limit on ppc64
powerpc/irq: Run softirqs off the top of the irq stack
Pull x86 fixes from Ingo Molnar:
"An EFI fix and two reboot-quirk fixes"
* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/reboot: Fix apparent cut-n-paste mistake in Dell reboot workaround
x86/reboot: Add quirk to make Dell C6100 use reboot=pci automatically
x86, efi: Don't map Boot Services on i386
Pull perf fixes from Ingo Molnar:
"Assorted standalone fixes"
* 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
perf/x86/intel: Add model number for Avoton Silvermont
perf: Fix capabilities bitfield compatibility in 'struct perf_event_mmap_page'
perf/x86/intel/uncore: Don't use smp_processor_id() in validate_group()
perf: Update ABI comment
tools lib lk: Uninclude linux/magic.h in debugfs.c
perf tools: Fix old GCC build error in trace-event-parse.c:parse_proc_kallsyms()
perf probe: Fix finder to find lines of given function
perf session: Check for SIGINT in more loops
perf tools: Fix compile with libelf without get_phdrnum
perf tools: Fix buildid cache handling of kallsyms with kcore
perf annotate: Fix objdump line parsing offset validation
perf tools: Fill in new definitions for madvise()/mmap() flags
perf tools: Sharpen the libaudit dependencies test
The check cpu_needs_post_dma_flush() in mips_dma_sync_sg_for_cpu() and
the check !plat_device_is_coherent() in mips_dma_sync_sg_for_device()
can be moved outside the for loop.
As a side effect, this also avoids a GCC bug that caused kernel compile
to fail with the error:
arch/mips/mm/dma-default.c: In function 'mips_dma_sync_sg_for_cpu':
arch/mips/mm/dma-default.c:316:1: internal compiler error: in add_insn_before, at emit-rtl.c:3852
This gcc failure is seen in Code Sourcery toolchains [e.g. gcc version
4.7.2 (Sourcery CodeBench Lite 2012.09-99)] after commit "MIPS: Optimize
current_cpu_type() for better code."
Signed-off-by: Jayachandran C <jchandra@broadcom.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/5907/
Reviewed-by: Markos Chandras <markos.chandras@imgtec.com>
Tested-by: Markos Chandras <markos.chandras@imgtec.com>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
On hosts with more than 168 GB of memory, a 32-bit guest may attempt
to grant map an MFN that is error cannot lookup in its mapping of the
m2p table. There is an m2p lookup as part of m2p_add_override() and
m2p_remove_override(). The lookup falls off the end of the mapped
portion of the m2p and (because the mapping is at the highest virtual
address) wraps around and the lookup causes a fault on what appears to
be a user space address.
do_page_fault() (thinking it's a fault to a userspace address), tries
to lock mm->mmap_sem. If the gntdev device is used for the grant map,
m2p_add_override() is called from from gnttab_mmap() with mm->mmap_sem
already locked. do_page_fault() then deadlocks.
The deadlock would most commonly occur when a 64-bit guest is started
and xenconsoled attempts to grant map its console ring.
Introduce mfn_to_pfn_no_overrides() which checks the MFN is within the
mapped portion of the m2p table before accessing the table and use
this in m2p_add_override(), m2p_remove_override(), and mfn_to_pfn()
(which already had the correct range check).
All faults caused by accessing the non-existant parts of the m2p are
thus within the kernel address space and exception_fixup() is called
without trying to lock mm->mmap_sem.
This means that for MFNs that are outside the mapped range of the m2p
then mfn_to_pfn() will always look in the m2p overrides. This is
correct because it must be a foreign MFN (and the PFN in the m2p in
this case is only relevant for the other domain).
Signed-off-by: David Vrabel <david.vrabel@citrix.com>
Cc: Stefano Stabellini <stefano.stabellini@citrix.com>
Cc: Jan Beulich <JBeulich@suse.com>
--
v3: check for auto_translated_physmap in mfn_to_pfn_no_overrides()
v2: in mfn_to_pfn() look in m2p_overrides if the MFN is out of
range as it's probably foreign.
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Acked-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Starting secondary CPUs early on from Open Firmware and placing them
in a holding spin loop slows down the boot process significantly under
some hypervisors such as KVM.
This is also unnecessary when RTAS supports querying the CPU state
So let's not do it.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
This makes the "OF" zImage wrapper (zImage.pseries, zImage.pmac,
zImage.maple) work if booted via a flat device-tree (ePAPR boot
mode), and thus potentially usable with kexec.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
We've been keeping that field in thread_struct for a while, it contains
the "limit" of the current stack pointer and is meant to be used for
detecting stack overflows.
It has a few problems however:
- First, it was never actually *used* on 64-bit. Set and updated but
not actually exploited
- When switching stack to/from irq and softirq stacks, it's update
is racy unless we hard disable interrupts, which is costly. This
is fine on 32-bit as we don't soft-disable there but not on 64-bit.
Thus rather than fixing 2 in order to implement 1 in some hypothetical
future, let's remove the code completely from 64-bit. In order to avoid
a clutter of ifdef's, we remove the updates from C code completely
during interrupt stack switching, and instead maintain it from the
asm helper that is used to do the stack switching in the first place.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Nowadays, irq_exit() calls __do_softirq() pretty much directly
instead of calling do_softirq() which switches to the decicated
softirq stack.
This has lead to observed stack overflows on powerpc since we call
irq_enter() and irq_exit() outside of the scope that switches to
the irq stack.
This fixes it by moving the stack switching up a level, making
irq_enter() and irq_exit() run off the irq stack.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
xen_init_spinlocks() currently calls static_key_slow_inc() before
jump_label_init() is invoked. When CONFIG_JUMP_LABEL is set (which usually is
the case) the effect of this static_key_slow_inc() is deferred until after
jump_label_init(). This is different from when CONFIG_JUMP_LABEL is not set, in
which case the key is set immediately. Thus, depending on the value of config
option, we may observe different behavior.
In addition, when we come to __jump_label_transform() from jump_label_init(),
the key (paravirt_ticketlocks_enabled) is already enabled. On processors where
ideal_nop is not the same as default_nop this will cause a BUG() since it is
expected that before a key is enabled the latter is replaced by the former
during initialization.
To address this problem we need to move
static_key_slow_inc(¶virt_ticketlocks_enabled) so that it is called
after jump_label_init(). We also need to make sure that this is done before
other cpus start to boot. early_initcall appears to be a good place to do so.
(Note that we cannot move whole xen_init_spinlocks() there since pv_lock_ops
need to be set before alternative_instructions() runs.)
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
[v2: Added extra comments in the code]
Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Reviewed-by: Steven Rostedt <rostedt@goodmis.org>
Pull ACPI and power management fixes from Rafael Wysocki:
1) Four fixes for cpufreq regressions introduced by the changes that
removed Device Tree parsing for CPU device nodes from cpufreq
drivers from Sudeep KarkadaNagesha.
2) Two fixes for recent cpufreq regressions introduced by changes
related to the preservation of sysfs attributes over system
suspend/resume cycles from Viresh Kumar.
3) Fix for ACPI-based wakeup signaling in the PCI subsystem that
fails to stop PME polling for devices put into the D3cold power
state from Rafael J Wysocki.
4) Fix for bad interactions between cpufreq and udev on systems
supporting intel_pstate where acpi-cpufreq is available as well
from Yinghai Lu.
* tag 'pm+acpi-3.12-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
cpufreq: return EEXIST instead of EBUSY for second registering
PCI / ACPI / PM: Clear pme_poll for devices in D3cold on wakeup
ARM: shmobile: change dev_id to cpu0 while registering cpu clock
ARM: i.MX: change dev_id to cpu0 while registering cpu clock
cpufreq: imx6q-cpufreq: assign cpu_dev correctly to cpu0 device
cpufreq: cpufreq-cpu0: assign cpu_dev correctly to cpu0 device
cpufreq: unlock correct rwsem while updating policy->cpu
cpufreq: Clear policy->cpus bits in __cpufreq_remove_dev_finish()
Pull ARM64 fixes from Catalin Marinas:
- Compat register fault reporting fix
- Documentation clarification on tagged pointers
- hwcap widened to 64-bit (user space already reading it as 64-bit)
* tag 'arm64-stable' of git://git.kernel.org/pub/scm/linux/kernel/git/cmarinas/linux-aarch64:
arm64: Widen hwcap to be 64 bit
arm64: Correctly report LR and SP for compat tasks
arm64: documentation: tighten up tagged pointer documentation
arm64: Make do_bad_area() function static
Under arm64 elf_hwcap is a 32 bit quantity, but it is stored in
a 64 bit auxiliary ELF field and glibc reads hwcap as 64 bit.
This patch widens elf_hwcap to be 64 bit.
Signed-off-by: Steve Capper <steve.capper@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
When a task crashes and we print debugging information, ensure that
compat tasks show the actual AArch32 LR and SP registers rather than the
AArch64 ones.
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Pull EFI fix from Matt Flemin:
" * Fix WARNING on i386 by only enabling a workaround for x86-64 since
we've never encountered the bug on i386 - Josh Boyer "
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Paul E. McKenney
Nathan Fontenot
Linus Torvalds
Jayachandran C
David Vrabel
Dave Jones
Benjamin Herrenschmidt
Konrad Rzeszutek Wilk
Maciej W. Rozycki
Masoud Sharbiani
Yan, Zheng
Steve Capper
Catalin Marinas
Ingo Molnar