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  1. 10 5月, 2012 1 次提交
  3. 09 5月, 2012 7 次提交
  5. 08 5月, 2012 2 次提交
    • D
      KVM: PPC: Book3S HV: Fix refcounting of hugepages · de6c0b02
      由 David Gibson 提交于 
      The H_REGISTER_VPA hcall implementation in HV Power KVM needs to pin some
guest memory pages into host memory so that they can be safely accessed
from usermode.  It does this used get_user_pages_fast().  When the VPA is
unregistered, or the VCPUs are cleaned up, these pages are released using
put_page().

However, the get_user_pages() is invoked on the specific memory are of the
VPA which could lie within hugepages.  In case the pinned page is huge,
we explicitly find the head page of the compound page before calling
put_page() on it.

At least with the latest kernel, this is not correct.  put_page() already
handles finding the correct head page of a compound, and also deals with
various counts on the individual tail page which are important for
transparent huge pages.  We don't support transparent hugepages on Power,
but even so, bypassing this count maintenance can lead (when the VM ends)
to a hugepage being released back to the pool with a non-zero mapcount on
one of the tail pages.  This can then lead to a bad_page() when the page
is released from the hugepage pool.

This removes the explicit compound_head() call to correct this bug.
Signed-off-by: NDavid Gibson <david@gibson.dropbear.id.au>
Signed-off-by: NPaul Mackerras <paulus@samba.org>
Acked-by: NAlexander Graf <agraf@suse.de>
Signed-off-by: NAvi Kivity <avi@redhat.com>
      de6c0b02
    • D
      xen/pci: don't use PCI BIOS service for configuration space accesses · 76a8df7b
      由 David Vrabel 提交于 
      The accessing PCI configuration space with the PCI BIOS32 service does
not work in PV guests.

On systems without MMCONFIG or where the BIOS hasn't marked the
MMCONFIG region as reserved in the e820 map, the BIOS service is
probed (even though direct access is preferred) and this hangs.

CC: stable@kernel.org
Acked-by: NJan Beulich <jbeulich@suse.com>
Signed-off-by: NDavid Vrabel <david.vrabel@citrix.com>
[v1: Fixed compile error when CONFIG_PCI is not set]
Signed-off-by: NKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>
      76a8df7b
  7. 07 5月, 2012 4 次提交
    • K
      xen/pte: Fix crashes when trying to see non-existent PGD/PMD/PUD/PTEs · b7e5ffe5
      由 Konrad Rzeszutek Wilk 提交于 
      If I try to do "cat /sys/kernel/debug/kernel_page_tables"
I end up with:

BUG: unable to handle kernel paging request at ffffc7fffffff000
IP: [<ffffffff8106aa51>] ptdump_show+0x221/0x480
PGD 0
Oops: 0000 [#1] SMP
CPU 0
.. snip..
RAX: 0000000000000000 RBX: ffffc00000000fff RCX: 0000000000000000
RDX: 0000800000000000 RSI: 0000000000000000 RDI: ffffc7fffffff000

which is due to the fact we are trying to access a PFN that is not
accessible to us. The reason (at least in this case) was that
PGD[256] is set to __HYPERVISOR_VIRT_START which was setup (by the
hypervisor) to point to a read-only linear map of the MFN->PFN array.
During our parsing we would get the MFN (a valid one), try to look
it up in the MFN->PFN tree and find it invalid and return ~0 as PFN.
Then pte_mfn_to_pfn would happilly feed that in, attach the flags
and return it back to the caller. 'ptdump_show' bitshifts it and
gets and invalid value that it tries to dereference.

Instead of doing all of that, we detect the ~0 case and just
return !_PAGE_PRESENT.

This bug has been in existence .. at least until 2.6.37 (yikes!)

CC: stable@kernel.org
Signed-off-by: NKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>
      b7e5ffe5
    • K
      xen/apic: Return the APIC ID (and version) for CPU 0. · 558daa28
      由 Konrad Rzeszutek Wilk 提交于 
      On x86_64 on AMD machines where the first APIC_ID is not zero, we get:

ACPI: LAPIC (acpi_id[0x01] lapic_id[0x10] enabled)
BIOS bug: APIC version is 0 for CPU 1/0x10, fixing up to 0x10
BIOS bug: APIC version mismatch, boot CPU: 0, CPU 1: version 10

which means that when the ACPI processor driver loads and
tries to parse the _Pxx states it fails to do as, as it
ends up calling acpi_get_cpuid which does this:

for_each_possible_cpu(i) {
        if (cpu_physical_id(i) == apic_id)
                return i;
}

And the bootup CPU, has not been found so it fails and returns -1
for the first CPU - which then subsequently in the loop that
"acpi_processor_get_info" does results in returning an error, which
means that "acpi_processor_add" failing and per_cpu(processor)
is never set (and is NULL).

That means that when xen-acpi-processor tries to load (much much
later on) and parse the P-states it gets -ENODEV from
acpi_processor_register_performance() (which tries to read
the per_cpu(processor)) and fails to parse the data.
Reported-by-and-Tested-by: NStefan Bader <stefan.bader@canonical.com>
Suggested-by: NBoris Ostrovsky <boris.ostrovsky@amd.com>
[v2: Bit-shift APIC ID by 24 bits]
Signed-off-by: NKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>
      558daa28
    • L
      IA32 emulation: Fix build problem for modular ia32 a.out support · febb72a6
      由 Larry Finger 提交于 
      Commit ce7e5d2d ("x86: fix broken TASK_SIZE for ia32_aout") breaks
kernel builds when "CONFIG_IA32_AOUT=m" with

  ERROR: "set_personality_ia32" [arch/x86/ia32/ia32_aout.ko] undefined!
  make[1]: *** [__modpost] Error 1

The entry point needs to be exported.
Signed-off-by: NLarry Finger <Larry.Finger@lwfinger.net>
Acked-by: NAl Viro <viro@zeniv.linux.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      febb72a6
    • A
      x86: fix broken TASK_SIZE for ia32_aout · ce7e5d2d
      由 Al Viro 提交于 
      Setting TIF_IA32 in load_aout_binary() used to be enough; these days
TASK_SIZE is controlled by TIF_ADDR32 and that one doesn't get set
there.  Switch to use of set_personality_ia32()...
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      ce7e5d2d
  9. 06 5月, 2012 4 次提交
    • G
      KVM: Do not take reference to mm during async #PF · 62c49cc9
      由 Gleb Natapov 提交于 
      It turned to be totally unneeded. The reason the code was introduced is
so that KVM can prefault swapped in page, but prefault can fail even
if mm is pinned since page table can change anyway. KVM handles this
situation correctly though and does not inject spurious page faults.

Fixes:
 "INFO: SOFTIRQ-safe -> SOFTIRQ-unsafe lock order detected" warning while
 running LTP inside a KVM guest using the recent -next kernel.
Reported-by: NSasha Levin <levinsasha928@gmail.com>
Signed-off-by: NGleb Natapov <gleb@redhat.com>
Signed-off-by: NAvi Kivity <avi@redhat.com>
      62c49cc9
    • G
      KVM: ensure async PF event wakes up vcpu from halt · a4fa1635
      由 Gleb Natapov 提交于 
      If vcpu executes hlt instruction while async PF is waiting to be delivered
vcpu can block and deliver async PF only after another even wakes it
up. This happens because kvm_check_async_pf_completion() will remove
completion event from vcpu->async_pf.done before entering kvm_vcpu_block()
and this will make kvm_arch_vcpu_runnable() return false. The solution
is to make vcpu runnable when processing completion.
Signed-off-by: NGleb Natapov <gleb@redhat.com>
Signed-off-by: NAvi Kivity <avi@redhat.com>
      a4fa1635
    • C
      ARM: 7414/1: SMP: prevent use of the console when using idmap_pgd · fde165b2
      由 Colin Cross 提交于 
      Commit 4e8ee7de (ARM: SMP: use
idmap_pgd for mapping MMU enable during secondary booting)
switched secondary boot to use idmap_pgd, which is initialized
during early_initcall, instead of a page table initialized during
__cpu_up.  This causes idmap_pgd to contain the static mappings
but be missing all dynamic mappings.

If a console is registered that creates a dynamic mapping, the
printk in secondary_start_kernel will trigger a data abort on
the missing mapping before the exception handlers have been
initialized, leading to a hang.  Initial boot is not affected
because no consoles have been registered, and resume is usually
not affected because the offending console is suspended.
Onlining a cpu with hotplug triggers the problem.

A workaround is to the printk in secondary_start_kernel until
after the page tables have been switched back to init_mm.

Cc: <stable@vger.kernel.org>
Signed-off-by: NColin Cross <ccross@android.com>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>
      fde165b2
    • J
      TTY: pdc_cons, fix regression in close · 49a5f3cf
      由 Jiri Slaby 提交于 
      The test in pdc_console_tty_close '!tty->count' was always wrong
because tty->count is decremented after tty->ops->close is called and
thus can never be zero. Hence the 'then' branch was never executed and
the timer never deleted.

This did not matter until commit 5dd5bc40 ("TTY: pdc_cons, use
tty_port").  There we needed to set TTY in tty_port to NULL, but this
never happened due to the bug above.

So change the test to really trigger at the last close by changing the
condition to 'tty->count == 1'.

Well, the driver should not touch tty->count at all.  It should use
tty_port->count and count open count there itself.
Signed-off-by: NJiri Slaby <jslaby@suse.cz>
Reported-and-tested-by: NMikulas Patocka <mpatocka@redhat.com>
Cc: Kyle McMartin <kyle@mcmartin.ca>
Cc: Helge Deller <deller@gmx.de>
Cc: "James E.J. Bottomley" <jejb@parisc-linux.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      49a5f3cf
  11. 05 5月, 2012 6 次提交
  13. 04 5月, 2012 1 次提交
    • L
      vfs: make word-at-a-time accesses handle a non-existing page · e419b4cc
      由 Linus Torvalds 提交于 
      It turns out that there are more cases than CONFIG_DEBUG_PAGEALLOC that
can have holes in the kernel address space: it seems to happen easily
with Xen, and it looks like the AMD gart64 code will also punch holes
dynamically.

Actually hitting that case is still very unlikely, so just do the
access, and take an exception and fix it up for the very unlikely case
of it being a page-crosser with no next page.

And hey, this abstraction might even help other architectures that have
other issues with unaligned word accesses than the possible missing next
page.  IOW, this could do the byte order magic too.

Peter Anvin fixed a thinko in the shifting for the exception case.
Reported-and-tested-by: NJana Saout <jana@saout.de>
Cc:  Peter Anvin <hpa@zytor.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      e419b4cc
  15. 03 5月, 2012 4 次提交
  17. 01 5月, 2012 2 次提交
  19. 30 4月, 2012 3 次提交
    • G
      powerpc/pseries: Rivet CONFIG_EEH for pSeries platform · e49f7a99
      由 Gavin Shan 提交于 
      Recently, Ryan Wang tried to compile PPC pSeries platform without
CONFIG_EEH and eventually run into errors. Nishanth Aravamudan
helped to narrow down the root cause. Actually, the pSeries platform
depends on CONFIG_EEH heavily and that won't work properly without
EEH support.

According to Ben's suggestion, the patch make CONFIG_EEH invisible
and keep it as always selected on pSeries platform.
Signed-off-by: NGavin Shan <shangw@linux.vnet.ibm.com>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>
      e49f7a99
    • G
      powerpc/irqdomain: Fix broken NR_IRQ references · 4013369f
      由 Grant Likely 提交于 
      The switch from using irq_map to irq_alloc_desc*() for managing irq
number allocations introduced new bugs in some of the powerpc
interrupt code.  Several functions rely on the value of NR_IRQS to
determine the maximum irq number that could get allocated.  However,
with sparse_irq and using irq_alloc_desc*() the maximum possible irq
number is now specified with 'nr_irqs' which may be a number larger
than NR_IRQS.  This has caused breakage on powermac when
CONFIG_NR_IRQS is set to 32.

This patch removes most of the direct references to NR_IRQS in the
powerpc code and replaces them with either a nr_irqs reference or by
using the common for_each_irq_desc() macro.  The powerpc-specific
for_each_irq() macro is removed at the same time.

Also, the Cell axon_msi driver is refactored to remove the global
build assumption on the size of NR_IRQS and instead add a limit to the
maximum irq number when calling irq_domain_add_nomap().
Signed-off-by: NGrant Likely <grant.likely@secretlab.ca>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>
      4013369f
    • G
      powerpc/8xx: Fix NR_IRQ bugs and refactor 8xx interrupt controller · 8751ed14
      由 Grant Likely 提交于 
      The mpc8xx driver uses a reference to NR_IRQS that is buggy.  It uses
NR_IRQs for the array size of the ppc_cached_irq_mask bitmap, but
NR_IRQs could be smaller than the number of hardware irqs that
ppc_cached_irq_mask tracks.

Also, while fixing that problem, it became apparent that the interrupt
controller only supports 32 interrupt numbers, but it is written as if
it supports multiple register banks which is more complicated.

This patch pulls out the buggy reference to NR_IRQs and fixes the size
of the ppc_cached_irq_mask to match the number of HW irqs.  It also
drops the now-unnecessary code since ppc_cached_irq_mask is no longer
an array.
Signed-off-by: NGrant Likely <grant.likely@secretlab.ca>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>
      8751ed14
  21. 28 4月, 2012 6 次提交
    • W
      ARM: 7406/1: hotplug: copy the affinity mask when forcefully migrating IRQs · 5e7371de
      由 Will Deacon 提交于 
      When a CPU is hotplugged off, we migrate any IRQs currently affine to it
away and onto another online CPU by calling the irq_set_affinity
function of the relevant interrupt controller chip. This function
returns either IRQ_SET_MASK_OK or IRQ_SET_MASK_OK_NOCOPY, to indicate
whether irq_data.affinity was updated.

If we are forcefully migrating an interrupt (because the affinity mask
no longer identifies any online CPUs) then we should update the IRQ
affinity mask to reflect the new CPU set. Failure to do so can
potentially leave /proc/irq/n/smp_affinity identifying only offline
CPUs, which may confuse userspace IRQ balancing daemons.

This patch updates migrate_one_irq to copy the affinity mask when
the interrupt chip returns IRQ_SET_MASK_OK after forcefully changing the
affinity of an interrupt.

Cc: stable@vger.kernel.org
Reported-by: NLeif Lindholm <leif.lindholm@arm.com>
Signed-off-by: NWill Deacon <will.deacon@arm.com>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>
      5e7371de
    • W
      ARM: 7405/1: kexec: call platform_cpu_kill on the killer rather than the victim · 6fa99b7f
      由 Will Deacon 提交于 
      When performing a kexec on an SMP system, the secondary cores are stopped
by calling machine_shutdown(), which in turn issues IPIs to offline the
other CPUs. Unfortunately, this isn't enough to reboot the cores into
a new kernel (since they are just executing a cpu_relax loop somewhere
in memory) so we make use of platform_cpu_kill, part of the CPU hotplug
implementation, to place the cores somewhere safe. This function expects
to be called on the killing CPU for each core that it takes out.

This patch moves the platform_cpu_kill callback out of the IPI handler
and into smp_send_stop, therefore ensuring that it executes on the
killing CPU rather than on the victim, matching what the hotplug code
requires.

Cc: stable@vger.kernel.org
Reported-by: NRussell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: NWill Deacon <will.deacon@arm.com>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>
      6fa99b7f
    • W
      ARM: 7403/1: tls: remove covert channel via TPIDRURW · 6a1c5312
      由 Will Deacon 提交于 
      TPIDRURW is a user read/write register forming part of the group of
thread registers in more recent versions of the ARM architecture (~v6+).

Currently, the kernel does not touch this register, which allows tasks
to communicate covertly by reading and writing to the register without
context-switching affecting its contents.

This patch clears TPIDRURW when TPIDRURO is updated via the set_tls
macro, which is called directly from __switch_to. Since the current
behaviour makes the register useless to userspace as far as thread
pointers are concerned, simply clearing the register (rather than saving
and restoring it) will not cause any problems to userspace.

Cc: stable@vger.kernel.org
Signed-off-by: NWill Deacon <will.deacon@arm.com>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>
      6a1c5312
    • S
      ARM: 7401/1: mm: Fix section mismatches · 14904927
      由 Stephen Boyd 提交于 
      WARNING: vmlinux.o(.text+0x111b8): Section mismatch in reference
from the function arm_memory_present() to the function
.init.text:memory_present()
The function arm_memory_present() references
the function __init memory_present().
This is often because arm_memory_present lacks a __init
annotation or the annotation of memory_present is wrong.

WARNING: arch/arm/mm/built-in.o(.text+0x1edc): Section mismatch
in reference from the function alloc_init_pud() to the function
.init.text:alloc_init_section()
The function alloc_init_pud() references
the function __init alloc_init_section().
This is often because alloc_init_pud lacks a __init
annotation or the annotation of alloc_init_section is wrong.
Signed-off-by: NStephen Boyd <sboyd@codeaurora.org>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>
      14904927
    • D
      xen: correctly check for pending events when restoring irq flags · 7eb7ce4d
      由 David Vrabel 提交于 
      In xen_restore_fl_direct(), xen_force_evtchn_callback() was being
called even if no events were pending.  This resulted in (depending on
workload) about a 100 times as many xen_version hypercalls as
necessary.

Fix this by correcting the sense of the conditional jump.

This seems to give a significant performance benefit for some
workloads.

There is some subtle tricksy "..since the check here is trying to
check both pending and masked in a single cmpw, but I think this is
correct. It will call check_events now only when the combined
mask+pending word is 0x0001 (aka unmasked, pending)." (Ian)

CC: stable@kernel.org
Acked-by: NIan Campbell <ian.campbell@citrix.com>
Signed-off-by: NDavid Vrabel <david.vrabel@citrix.com>
Signed-off-by: NKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>
      7eb7ce4d
    • D
      MIPS: Remove get_current_pgd(). · dc5efaa0
      由 David Daney 提交于 
      It is unused in the tree.
Signed-off-by: NDavid Daney <ddaney@caviumnetworks.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/3557/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>
      dc5efaa0