linux-toradex.git/arch, branch v3.10.76

arc: mm: Fix build failure

2015-04-29T08:34:01+00:00

commit e262eb9381ad51b5de7a9e762ee773bbd25ce650 upstream.

Fix misspelled define.

Fixes: 33692f27597f ("vm: add VM_FAULT_SIGSEGV handling support")
Signed-off-by: Guenter Roeck 
Signed-off-by: Linus Torvalds 
Signed-off-by: Greg Kroah-Hartman

x86: mm: move mmap_sem unlock from mm_fault_error() to caller

2015-04-29T08:34:01+00:00

commit 7fb08eca45270d0ae86e1ad9d39c40b7a55d0190 upstream.

This replaces four copies in various stages of mm_fault_error() handling
with just a single one.  It will also allow for more natural placement
of the unlocking after some further cleanup.

Signed-off-by: Linus Torvalds 
Signed-off-by: Greg Kroah-Hartman

vm: add VM_FAULT_SIGSEGV handling support

2015-04-29T08:34:00+00:00

commit 33692f27597fcab536d7cbbcc8f52905133e4aa7 upstream.

The core VM already knows about VM_FAULT_SIGBUS, but cannot return a
"you should SIGSEGV" error, because the SIGSEGV case was generally
handled by the caller - usually the architecture fault handler.

That results in lots of duplication - all the architecture fault
handlers end up doing very similar "look up vma, check permissions, do
retries etc" - but it generally works.  However, there are cases where
the VM actually wants to SIGSEGV, and applications _expect_ SIGSEGV.

In particular, when accessing the stack guard page, libsigsegv expects a
SIGSEGV.  And it usually got one, because the stack growth is handled by
that duplicated architecture fault handler.

However, when the generic VM layer started propagating the error return
from the stack expansion in commit fee7e49d4514 ("mm: propagate error
from stack expansion even for guard page"), that now exposed the
existing VM_FAULT_SIGBUS result to user space.  And user space really
expected SIGSEGV, not SIGBUS.

To fix that case, we need to add a VM_FAULT_SIGSEGV, and teach all those
duplicate architecture fault handlers about it.  They all already have
the code to handle SIGSEGV, so it's about just tying that new return
value to the existing code, but it's all a bit annoying.

This is the mindless minimal patch to do this.  A more extensive patch
would be to try to gather up the mostly shared fault handling logic into
one generic helper routine, and long-term we really should do that
cleanup.

Just from this patch, you can generally see that most architectures just
copied (directly or indirectly) the old x86 way of doing things, but in
the meantime that original x86 model has been improved to hold the VM
semaphore for shorter times etc and to handle VM_FAULT_RETRY and other
"newer" things, so it would be a good idea to bring all those
improvements to the generic case and teach other architectures about
them too.

Reported-and-tested-by: Takashi Iwai 
Tested-by: Jan Engelhardt 
Acked-by: Heiko Carstens  # "s390 still compiles and boots"
Cc: linux-arch@vger.kernel.org
Signed-off-by: Linus Torvalds 
[shengyong: Backport to 3.10
 - adjust context
 - ignore modification for arch nios2, because 3.10 does not support it
 - ignore modification for driver lustre, because 3.10 does not support it
 - ignore VM_FAULT_FALLBACK in VM_FAULT_ERROR, becase 3.10 does not support
   this flag
 - add SIGSEGV handling to powerpc/cell spu_fault.c, because 3.10 does not
   separate it to copro_fault.c
 - add SIGSEGV handling in mm/memory.c, because 3.10 does not separate it
   to gup.c
]
Signed-off-by: Sheng Yong 
Signed-off-by: Greg Kroah-Hartman

move d_rcu from overlapping d_child to overlapping d_alias

2015-04-29T08:34:00+00:00

commit 946e51f2bf37f1656916eb75bd0742ba33983c28 upstream.

Signed-off-by: Al Viro 
Cc: Ben Hutchings 
[hujianyang: Backported to 3.10 refer to the work of Ben Hutchings in 3.2:
 - Apply name changes in all the different places we use d_alias and d_child
 - Move the WARN_ON() in __d_free() to d_free() as we don't have dentry_free()]
Signed-off-by: hujianyang 
Signed-off-by: Greg Kroah-Hartman

KVM: x86: SYSENTER emulation is broken

2015-04-29T08:33:59+00:00

commit f3747379accba8e95d70cec0eae0582c8c182050 upstream.

SYSENTER emulation is broken in several ways:
1. It misses the case of 16-bit code segments completely (CVE-2015-0239).
2. MSR_IA32_SYSENTER_CS is checked in 64-bit mode incorrectly (bits 0 and 1 can
   still be set without causing #GP).
3. MSR_IA32_SYSENTER_EIP and MSR_IA32_SYSENTER_ESP are not masked in
   legacy-mode.
4. There is some unneeded code.

Fix it.

Signed-off-by: Nadav Amit 
Signed-off-by: Paolo Bonzini 
[zhangzhiqiang: backport to 3.10:
 - adjust context
 - in 3.10 context "ctxt->eflags &= ~(EFLG_VM | EFLG_IF | EFLG_RF)" is replaced by
   "ctxt->eflags &= ~(EFLG_VM | EFLG_IF)" in upstream, which was changed by another commit.
 - After the above adjustments, becomes same to the original patch:
       https://github.com/torvalds/linux/commit/f3747379accba8e95d70cec0eae0582c8c182050
]
Signed-off-by: Zhiqiang Zhang 
Signed-off-by: Greg Kroah-Hartman

powerpc/mpc85xx: Add ranges to etsec2 nodes

2015-04-13T12:02:12+00:00

commit bb344ca5b90df62b1a3b7a35c6a9d00b306a170d upstream.

Commit 746c9e9f92dd "of/base: Fix PowerPC address parsing hack" limited
the applicability of the workaround whereby a missing ranges is treated
as an empty ranges.  This workaround was hiding a bug in the etsec2
device tree nodes, which have children with reg, but did not have
ranges.

Signed-off-by: Scott Wood 
Reported-by: Alexander Graf 
Signed-off-by: Greg Kroah-Hartman

ARM: at91: pm: fix at91rm9200 standby

2015-03-26T14:01:01+00:00

commit 84e871660bebfddb9a62ebd6f19d02536e782f0a upstream.

at91rm9200 standby and suspend to ram has been broken since
00482a4078f4. It is wrongly using AT91_BASE_SYS which is a physical address
and actually doesn't correspond to any register on at91rm9200.

Use the correct at91_ramc_base[0] instead.

Fixes: 00482a4078f4 (ARM: at91: implement the standby function for pm/cpuidle)

Signed-off-by: Alexandre Belloni 
Signed-off-by: Nicolas Ferre 
Signed-off-by: Greg Kroah-Hartman

powerpc/smp: Wait until secondaries are active & online

2015-03-26T14:01:00+00:00

commit 875ebe940d77a41682c367ad799b4f39f128d3fa upstream.

Anton has a busy ppc64le KVM box where guests sometimes hit the infamous
"kernel BUG at kernel/smpboot.c:134!" issue during boot:

  BUG_ON(td->cpu != smp_processor_id());

Basically a per CPU hotplug thread scheduled on the wrong CPU. The oops
output confirms it:

  CPU: 0
  Comm: watchdog/130

The problem is that we aren't ensuring the CPU active bit is set for the
secondary before allowing the master to continue on. The master unparks
the secondary CPU's kthreads and the scheduler looks for a CPU to run
on. It calls select_task_rq() and realises the suggested CPU is not in
the cpus_allowed mask. It then ends up in select_fallback_rq(), and
since the active bit isnt't set we choose some other CPU to run on.

This seems to have been introduced by 6acbfb96976f "sched: Fix hotplug
vs. set_cpus_allowed_ptr()", which changed from setting active before
online to setting active after online. However that was in turn fixing a
bug where other code assumed an active CPU was also online, so we can't
just revert that fix.

The simplest fix is just to spin waiting for both active & online to be
set. We already have a barrier prior to set_cpu_online() (which also
sets active), to ensure all other setup is completed before online &
active are set.

Fixes: 6acbfb96976f ("sched: Fix hotplug vs. set_cpus_allowed_ptr()")
Signed-off-by: Michael Ellerman 
Signed-off-by: Anton Blanchard 
Signed-off-by: Michael Ellerman 
Signed-off-by: Greg Kroah-Hartman

x86/vdso: Fix the build on GCC5

2015-03-26T14:01:00+00:00

commit e893286918d2cde3a94850d8f7101cd1039e0c62 upstream.

On gcc5 the kernel does not link:

  ld: .eh_frame_hdr table[4] FDE at 0000000000000648 overlaps table[5] FDE at 0000000000000670.

Because prior GCC versions always emitted NOPs on ALIGN directives, but
gcc5 started omitting them.

.LSTARTFDEDLSI1 says:

        /* HACK: The dwarf2 unwind routines will subtract 1 from the
           return address to get an address in the middle of the
           presumed call instruction.  Since we didn't get here via
           a call, we need to include the nop before the real start
           to make up for it.  */
        .long .LSTART_sigreturn-1-.     /* PC-relative start address */

But commit 69d0627a7f6e ("x86 vDSO: reorder vdso32 code") from 2.6.25
replaced .org __kernel_vsyscall+32,0x90 by ALIGN right before
__kernel_sigreturn.

Of course, ALIGN need not generate any NOP in there. Esp. gcc5 collapses
vclock_gettime.o and int80.o together with no generated NOPs as "ALIGN".

So fix this by adding to that point at least a single NOP and make the
function ALIGN possibly with more NOPs then.

Kudos for reporting and diagnosing should go to Richard.

Reported-by: Richard Biener 
Signed-off-by: Jiri Slaby 
Acked-by: Andy Lutomirski 
Cc: Borislav Petkov 
Cc: H. Peter Anvin 
Cc: Linus Torvalds 
Cc: Thomas Gleixner 
Link: http://lkml.kernel.org/r/1425543211-12542-1-git-send-email-jslaby@suse.cz
Signed-off-by: Ingo Molnar 
Signed-off-by: Greg Kroah-Hartman

x86/fpu: Drop_fpu() should not assume that tsk equals current

2015-03-26T14:01:00+00:00

commit f4c3686386393c120710dd34df2a74183ab805fd upstream.

drop_fpu() does clear_used_math() and usually this is correct
because tsk == current.

However switch_fpu_finish()->restore_fpu_checking() is called before
__switch_to() updates the "current_task" variable. If it fails,
we will wrongly clear the PF_USED_MATH flag of the previous task.

So use clear_stopped_child_used_math() instead.

Signed-off-by: Oleg Nesterov 
Signed-off-by: Borislav Petkov 
Reviewed-by: Rik van Riel 
Cc: Andy Lutomirski 
Cc: Borislav Petkov 
Cc: Dave Hansen 
Cc: Fenghua Yu 
Cc: H. Peter Anvin 
Cc: Linus Torvalds 
Cc: Pekka Riikonen 
Cc: Quentin Casasnovas 
Cc: Suresh Siddha 
Cc: Thomas Gleixner 
Link: http://lkml.kernel.org/r/20150309171041.GB11388@redhat.com
Signed-off-by: Ingo Molnar 
Signed-off-by: Greg Kroah-Hartman