linux-stable.git/arch, branch v3.4.41

x86, mm: Patch out arch_flush_lazy_mmu_mode() when running on bare metal

2013-04-17T04:27:27+00:00

commit 511ba86e1d386f671084b5d0e6f110bb30b8eeb2 upstream.

Invoking arch_flush_lazy_mmu_mode() results in calls to
preempt_enable()/disable() which may have performance impact.

Since lazy MMU is not used on bare metal we can patch away
arch_flush_lazy_mmu_mode() so that it is never called in such
environment.

[ hpa: the previous patch "Fix vmalloc_fault oops during lazy MMU
  updates" may cause a minor performance regression on
  bare metal.  This patch resolves that performance regression.  It is
  somewhat unclear to me if this is a good -stable candidate. ]

Signed-off-by: Boris Ostrovsky 
Link: http://lkml.kernel.org/r/1364045796-10720-2-git-send-email-konrad.wilk@oracle.com
Tested-by: Josh Boyer 
Tested-by: Konrad Rzeszutek Wilk 
Acked-by: Borislav Petkov 
Signed-off-by: Konrad Rzeszutek Wilk 
Signed-off-by: H. Peter Anvin 
Signed-off-by: Greg Kroah-Hartman

x86, mm, paravirt: Fix vmalloc_fault oops during lazy MMU updates

2013-04-17T04:27:27+00:00

commit 1160c2779b826c6f5c08e5cc542de58fd1f667d5 upstream.

In paravirtualized x86_64 kernels, vmalloc_fault may cause an oops
when lazy MMU updates are enabled, because set_pgd effects are being
deferred.

One instance of this problem is during process mm cleanup with memory
cgroups enabled. The chain of events is as follows:

- zap_pte_range enables lazy MMU updates
- zap_pte_range eventually calls mem_cgroup_charge_statistics,
  which accesses the vmalloc'd mem_cgroup per-cpu stat area
- vmalloc_fault is triggered which tries to sync the corresponding
  PGD entry with set_pgd, but the update is deferred
- vmalloc_fault oopses due to a mismatch in the PUD entries

The OOPs usually looks as so:

------------[ cut here ]------------
kernel BUG at arch/x86/mm/fault.c:396!
invalid opcode: 0000 [#1] SMP
.. snip ..
CPU 1
Pid: 10866, comm: httpd Not tainted 3.6.10-4.fc18.x86_64 #1
RIP: e030:[]  [] vmalloc_fault+0x11f/0x208
.. snip ..
Call Trace:
 [] do_page_fault+0x399/0x4b0
 [] ? xen_mc_extend_args+0xec/0x110
 [] page_fault+0x25/0x30
 [] ? mem_cgroup_charge_statistics.isra.13+0x13/0x50
 [] __mem_cgroup_uncharge_common+0xd8/0x350
 [] mem_cgroup_uncharge_page+0x57/0x60
 [] page_remove_rmap+0xe0/0x150
 [] ? vm_normal_page+0x1a/0x80
 [] unmap_single_vma+0x531/0x870
 [] unmap_vmas+0x52/0xa0
 [] ? pte_mfn_to_pfn+0x72/0x100
 [] exit_mmap+0x98/0x170
 [] ? __raw_callee_save_xen_pmd_val+0x11/0x1e
 [] mmput+0x83/0xf0
 [] exit_mm+0x104/0x130
 [] do_exit+0x15a/0x8c0
 [] do_group_exit+0x3f/0xa0
 [] sys_exit_group+0x17/0x20
 [] system_call_fastpath+0x16/0x1b

Calling arch_flush_lazy_mmu_mode immediately after set_pgd makes the
changes visible to the consistency checks.

RedHat-Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=914737
Tested-by: Josh Boyer 
Reported-and-Tested-by: Krishna Raman 
Signed-off-by: Samu Kallio 
Link: http://lkml.kernel.org/r/1364045796-10720-1-git-send-email-konrad.wilk@oracle.com
Tested-by: Konrad Rzeszutek Wilk 
Signed-off-by: Konrad Rzeszutek Wilk 
Signed-off-by: H. Peter Anvin 
Signed-off-by: Greg Kroah-Hartman

x86: Fix rebuild with EFI_STUB enabled

2013-04-12T16:38:46+00:00

commit 918708245e92941df16a634dc201b407d12bcd91 upstream.

eboot.o and efi_stub_$(BITS).o didn't get added to "targets", and hence
their .cmd files don't get included by the build machinery, leading to
the files always getting rebuilt.

Rather than adding the two files individually, take the opportunity and
add $(VMLINUX_OBJS) to "targets" instead, thus allowing the assignment
at the top of the file to be shrunk quite a bit.

At the same time, remove a pointless flags override line - the variable
assigned to was misspelled anyway, and the options added are
meaningless for assembly sources.

[ hpa: the patch is not minimal, but I am taking it for -urgent anyway
  since the excess impact of the patch seems to be small enough. ]

Signed-off-by: Jan Beulich 
Link: http://lkml.kernel.org/r/515C5D2502000078000CA6AD@nat28.tlf.novell.com
Cc: Matthew Garrett 
Cc: Matt Fleming 
Signed-off-by: H. Peter Anvin 
Signed-off-by: Greg Kroah-Hartman

x86: remove the x32 syscall bitmask from syscall_get_nr()

2013-04-12T16:38:45+00:00

commit 8b4b9f27e57584f3d90e0bb84cf800ad81cfe3a1 upstream.

Commit fca460f95e928bae373daa8295877b6905bc62b8 simplified the x32
implementation by creating a syscall bitmask, equal to 0x40000000, that
could be applied to x32 syscalls such that the masked syscall number
would be the same as a x86_64 syscall.  While that patch was a nice
way to simplify the code, it went a bit too far by adding the mask to
syscall_get_nr(); returning the masked syscall numbers can cause
confusion with callers that expect syscall numbers matching the x32
ABI, e.g. unmasked syscall numbers.

This patch fixes this by simply removing the mask from syscall_get_nr()
while preserving the other changes from the original commit.  While
there are several syscall_get_nr() callers in the kernel, most simply
check that the syscall number is greater than zero, in this case this
patch will have no effect.  Of those remaining callers, they appear
to be few, seccomp and ftrace, and from my testing of seccomp without
this patch the original commit definitely breaks things; the seccomp
filter does not correctly filter the syscalls due to the difference in
syscall numbers in the BPF filter and the value from syscall_get_nr().
Applying this patch restores the seccomp BPF filter functionality on
x32.

I've tested this patch with the seccomp BPF filters as well as ftrace
and everything looks reasonable to me; needless to say general usage
seemed fine as well.

Signed-off-by: Paul Moore 
Link: http://lkml.kernel.org/r/20130215172143.12549.10292.stgit@localhost
Cc: Will Drewry 
Cc: H. Peter Anvin 
Signed-off-by: H. Peter Anvin 
Signed-off-by: Greg Kroah-Hartman

powerpc: pSeries_lpar_hpte_remove fails from Adjunct partition being performed before the ANDCOND test

2013-04-12T16:38:45+00:00

commit 9fb2640159f9d4f5a2a9d60e490482d4cbecafdb upstream.

Some versions of pHyp will perform the adjunct partition test before the
ANDCOND test.  The result of this is that H_RESOURCE can be returned and
cause the BUG_ON condition to occur. The HPTE is not removed.  So add a
check for H_RESOURCE, it is ok if this HPTE is not removed as
pSeries_lpar_hpte_remove is looking for an HPTE to remove and not a
specific HPTE to remove.  So it is ok to just move on to the next slot
and try again.

Signed-off-by: Michael Wolf 
Signed-off-by: Stephen Rothwell 
Signed-off-by: Greg Kroah-Hartman

alpha: Add irongate_io to PCI bus resources

2013-04-12T16:38:45+00:00

commit aa8b4be3ac049c8b1df2a87e4d1d902ccfc1f7a9 upstream.

Fixes a NULL pointer dereference at boot on UP1500.

Reviewed-and-Tested-by: Matt Turner 
Signed-off-by: Jay Estabrook 
Signed-off-by: Matt Turner 
Signed-off-by: Michael Cree 
Signed-off-by: Linus Torvalds 
Signed-off-by: Greg Kroah-Hartman

ARM: cns3xxx: fix mapping of private memory region

2013-04-05T17:04:35+00:00

commit a3d9052c6296ad3398d3ad649c3c682c3e7ecfa6 upstream.

Since commit 0536bdf33faf (ARM: move iotable mappings within the vmalloc
region), the Cavium CNS3xxx cannot boot anymore.

This is caused by the pre-defined iotable mappings is not in the vmalloc
region. This patch move the iotable mappings into the vmalloc region, and
merge the MPCore private memory region (containing the SCU, the GIC and
the TWD) as a single region.

Signed-off-by: Mac Lin 
Signed-off-by: Anton Vorontsov 
Signed-off-by: Greg Kroah-Hartman

tile: expect new initramfs name from hypervisor file system

2013-04-05T17:04:14+00:00

commit ff7f3efb9abf986f4ecd8793a9593f7ca4d6431a upstream.

The current Tilera boot infrastructure now provides the initramfs
to Linux as a Tilera-hypervisor file named "initramfs", rather than
"initramfs.cpio.gz", as before.  (This makes it reasonable to use
other compression techniques than gzip on the file without having to
worry about the name causing confusion.)  Adapt to use the new name,
but also fall back to checking for the old name.

Cc'ing to stable so that older kernels will remain compatible with
newer Tilera boot infrastructure.

Signed-off-by: Chris Metcalf 
Signed-off-by: Greg Kroah-Hartman

signal: Define __ARCH_HAS_SA_RESTORER so we know whether to clear sa_restorer

2013-04-05T17:04:14+00:00

Vaguely based on upstream commit 574c4866e33d 'consolidate kernel-side
struct sigaction declarations'.

flush_signal_handlers() needs to know whether sigaction::sa_restorer
is defined, not whether SA_RESTORER is defined.  Define the
__ARCH_HAS_SA_RESTORER macro to indicate this.

Signed-off-by: Ben Hutchings 
Cc: Al Viro 
Signed-off-by: Greg Kroah-Hartman

x86-64: Fix the failure case in copy_user_handle_tail()

2013-03-28T19:12:26+00:00

commit 66db3feb486c01349f767b98ebb10b0c3d2d021b upstream.

The increment of "to" in copy_user_handle_tail() will have incremented
before a failure has been noted.  This causes us to skip a byte in the
failure case.

Only do the increment when assured there is no failure.

Signed-off-by: CQ Tang 
Link: http://lkml.kernel.org/r/20130318150221.8439.993.stgit@phlsvslse11.ph.intel.com
Signed-off-by: Mike Marciniszyn 
Signed-off-by: H. Peter Anvin 
Signed-off-by: Greg Kroah-Hartman