linux-toradex.git/arch, branch v3.0.69

ARM: fix scheduling while atomic warning in alignment handling code

2013-03-14T18:32:04+00:00

commit b255188f90e2bade1bd11a986dd1ca4861869f4d upstream.

Paolo Pisati reports that IPv6 triggers this warning:

BUG: scheduling while atomic: swapper/0/0/0x40000100
Modules linked in:
[] (unwind_backtrace+0x0/0xf0) from [] (__schedule_bug+0x48/0x5c)
[] (__schedule_bug+0x48/0x5c) from [] (__schedule+0x700/0x740)
[] (__schedule+0x700/0x740) from [] (__cond_resched+0x24/0x34)
[] (__cond_resched+0x24/0x34) from [] (_cond_resched+0x3c/0x44)
[] (_cond_resched+0x3c/0x44) from [] (do_alignment+0x178/0x78c)
[] (do_alignment+0x178/0x78c) from [] (do_DataAbort+0x34/0x98)
[] (do_DataAbort+0x34/0x98) from [] (__dabt_svc+0x40/0x60)
Exception stack(0xc0763d70 to 0xc0763db8)
3d60:                                     e97e805e e97e806e 2c000000 11000000
3d80: ea86bb00 0000002c 00000011 e97e807e c076d2a8 e97e805e e97e806e 0000002c
3da0: 3d000000 c0763dbc c04b98fc c02a8490 00000113 ffffffff
[] (__dabt_svc+0x40/0x60) from [] (__csum_ipv6_magic+0x8/0xc8)

Fix this by using probe_kernel_address() stead of __get_user().

Reported-by: Paolo Pisati 
Tested-by: Paolo Pisati 
Signed-off-by: Russell King 
Signed-off-by: Greg Kroah-Hartman

ARM: VFP: fix emulation of second VFP instruction

2013-03-14T18:32:03+00:00

commit 5e4ba617c1b584b2e376f31a63bd4e734109318a upstream.

Martin Storsjö reports that the sequence:

        ee312ac1        vsub.f32        s4, s3, s2
        ee702ac0        vsub.f32        s5, s1, s0
        e59f0028        ldr             r0, [pc, #40]
        ee111a90        vmov            r1, s3

on Raspberry Pi (implementor 41 architecture 1 part 20 variant b rev 5)
where s3 is a denormal and s2 is zero results in incorrect behaviour -
the instruction "vsub.f32 s5, s1, s0" is not executed:

        VFP: bounce: trigger ee111a90 fpexc d0000780
        VFP: emulate: INST=0xee312ac1 SCR=0x00000000
        ...

As we can see, the instruction triggering the exception is the "vmov"
instruction, and we emulate the "vsub.f32 s4, s3, s2" but fail to
properly take account of the FPEXC_FP2V flag in FPEXC.  This is because
the test for the second instruction register being valid is bogus, and
will always skip emulation of the second instruction.

Reported-by: Martin Storsjö 
Tested-by: Martin Storsjö 
Signed-off-by: Russell King 
Signed-off-by: Greg Kroah-Hartman

s390/kvm: Fix store status for ACRS/FPRS fix

2013-03-03T22:09:07+00:00

In 3.0.67, commit 58c9ce6fad8e00d9726447f939fe7e78e2aec891 (s390/kvm:
Fix store status for ACRS/FPRS), upstream commit
15bc8d8457875f495c59d933b05770ba88d1eacb, added a call to
save_access_regs to save ACRS. But we do not have ARCS in kvm_run in
3.0 yet, so this results in:
arch/s390/kvm/kvm-s390.c: In function 'kvm_s390_vcpu_store_status':
arch/s390/kvm/kvm-s390.c:593: error: 'struct kvm_run' has no member named 's'

Fix it by saving guest_acrs which is where ARCS are in 3.0.

Signed-off-by: Jiri Slaby 
Signed-off-by: Greg Kroah-Hartman

x86/apic: Work around boot failure on HP ProLiant DL980 G7 Server systems

2013-03-03T22:09:06+00:00

commit cb214ede7657db458fd0b2a25ea0b28dbf900ebc upstream.

When a HP ProLiant DL980 G7 Server boots a regular kernel,
there will be intermittent lost interrupts which could
result in a hang or (in extreme cases) data loss.

The reason is that this system only supports x2apic physical
mode, while the kernel boots with a logical-cluster default
setting.

This bug can be worked around by specifying the "x2apic_phys" or
"nox2apic" boot option, but we want to handle this system
without requiring manual workarounds.

The BIOS sets ACPI_FADT_APIC_PHYSICAL in FADT table.
As all apicids are smaller than 255, BIOS need to pass the
control to the OS with xapic mode, according to x2apic-spec,
chapter 2.9.

Current code handle x2apic when BIOS pass with xapic mode
enabled:

When user specifies x2apic_phys, or FADT indicates PHYSICAL:

1. During madt oem check, apic driver is set with xapic logical
   or xapic phys driver at first.

2. enable_IR_x2apic() will enable x2apic_mode.

3. if user specifies x2apic_phys on the boot line, x2apic_phys_probe()
   will install the correct x2apic phys driver and use x2apic phys mode.
   Otherwise it will skip the driver will let x2apic_cluster_probe to
   take over to install x2apic cluster driver (wrong one) even though FADT
   indicates PHYSICAL, because x2apic_phys_probe does not check
   FADT PHYSICAL.

Add checking x2apic_fadt_phys in x2apic_phys_probe() to fix the
problem.

Signed-off-by: Stoney Wang 
[ updated the changelog and simplified the code ]
Signed-off-by: Yinghai Lu 
Signed-off-by: Zhang Lin-Bao 
[ make a patch specially for 3.0.66]
Link: http://lkml.kernel.org/r/1360263182-16226-1-git-send-email-yinghai@kernel.org
Signed-off-by: Ingo Molnar 
Signed-off-by: Greg Kroah-Hartman

x86: Do not leak kernel page mapping locations

2013-03-03T22:09:06+00:00

commit e575a86fdc50d013bf3ad3aa81d9100e8e6cc60d upstream.

Without this patch, it is trivial to determine kernel page
mappings by examining the error code reported to dmesg[1].
Instead, declare the entire kernel memory space as a violation
of a present page.

Additionally, since show_unhandled_signals is enabled by
default, switch branch hinting to the more realistic
expectation, and unobfuscate the setting of the PF_PROT bit to
improve readability.

[1] http://vulnfactory.org/blog/2013/02/06/a-linux-memory-trick/

Reported-by: Dan Rosenberg 
Suggested-by: Brad Spengler 
Signed-off-by: Kees Cook 
Acked-by: H. Peter Anvin 
Cc: Paul E. McKenney 
Cc: Frederic Weisbecker 
Cc: Eric W. Biederman 
Cc: Linus Torvalds 
Cc: Andrew Morton 
Cc: Peter Zijlstra 
Link: http://lkml.kernel.org/r/20130207174413.GA12485@www.outflux.net
Signed-off-by: Ingo Molnar 
Signed-off-by: CAI Qian 
Signed-off-by: Greg Kroah-Hartman

x86: Make sure we can boot in the case the BDA contains pure garbage

2013-03-03T22:09:03+00:00

commit 7c10093692ed2e6f318387d96b829320aa0ca64c upstream.

On non-BIOS platforms it is possible that the BIOS data area contains
garbage instead of being zeroed or something equivalent (firmware
people: we are talking of 1.5K here, so please do the sane thing.)

We need on the order of 20-30K of low memory in order to boot, which
may grow up to < 64K in the future.  We probably want to avoid the
lowest of the low memory.  At the same time, it seems extremely
unlikely that a legitimate EBDA would ever reach down to the 128K
(which would require it to be over half a megabyte in size.)  Thus,
pick 128K as the cutoff for "this is insane, ignore."  We may still
end up reserving a bunch of extra memory on the low megabyte, but that
is not really a major issue these days.  In the worst case we lose
512K of RAM.

This code really should be merged with trim_bios_range() in
arch/x86/kernel/setup.c, but that is a bigger patch for a later merge
window.

Reported-by: Darren Hart 
Signed-off-by: H. Peter Anvin 
Cc: Matt Fleming 
Link: http://lkml.kernel.org/n/tip-oebml055yyfm8yxmria09rja@git.kernel.org
Signed-off-by: Greg Kroah-Hartman

iommu/amd: Initialize device table after dma_ops

2013-03-03T22:09:03+00:00

commit f528d980c17b8714aedc918ba86e058af914d66b upstream.

When dma_ops are initialized the unity mappings are
created. The init_device_table_dma() function makes sure DMA
from all devices is blocked by default. This opens a short
window in time where DMA to unity mapped regions is blocked
by the IOMMU. Make sure this does not happen by initializing
the device table after dma_ops.

Signed-off-by: Joerg Roedel 
Signed-off-by: Shuah Khan 
Signed-off-by: Greg Kroah-Hartman

Purge existing TLB entries in set_pte_at and ptep_set_wrprotect

2013-02-28T14:32:27+00:00

commit 7139bc1579901b53db7e898789e916ee2fb52d78 upstream.

This patch goes a long way toward fixing the minifail bug, and
it  significantly improves the stability of SMP machines such as
the rp3440.  When write  protecting a page for COW, we need to
purge the existing translation.  Otherwise, the COW break
doesn't occur as expected because the TLB may still have a stale entry
which allows writes.

[jejb: fix up checkpatch errors]
Signed-off-by: John David Anglin 
Signed-off-by: James Bottomley 
Signed-off-by: Greg Kroah-Hartman

powerpc/kexec: Disable hard IRQ before kexec

2013-02-28T14:32:26+00:00

commit 8520e443aa56cc157b015205ea53e7b9fc831291 upstream.

Disable hard IRQ before kexec a new kernel image.
Not doing it can result in corrupted data in the memory segments
reserved for the new kernel.

Signed-off-by: Phileas Fogg 
Signed-off-by: Benjamin Herrenschmidt 
Signed-off-by: Greg Kroah-Hartman

ARM: PXA3xx: program the CSMSADRCFG register

2013-02-28T14:32:26+00:00

commit d107a204154ddd79339203c2deeb7433f0cf6777 upstream.

The Chip Select Configuration Register must be programmed to 0x2 in
order to achieve the correct behavior of the Static Memory Controller.

Without this patch devices wired to DFI and accessed through SMC cannot
be accessed after resume from S2.

Do not rely on the boot loader to program the CSMSADRCFG register by
programming it in the kernel smemc module.

Signed-off-by: Igor Grinberg 
Acked-by: Eric Miao 
Signed-off-by: Haojian Zhuang 
Signed-off-by: Greg Kroah-Hartman