linux-toradex.git/arch, branch v3.7.6

x86/Sandy Bridge: Sandy Bridge workaround depends on CONFIG_PCI

2013-02-04T00:27:07+00:00

commit e43b3cec711a61edf047adf6204d542f3a659ef8 upstream.

early_pci_allowed() and read_pci_config_16() are only available if
CONFIG_PCI is defined.

Signed-off-by: H. Peter Anvin 
Cc: Jesse Barnes 
Signed-off-by: Abdallah Chatila

x86, efi: Set runtime_version to the EFI spec revision

2013-02-04T00:27:06+00:00

commit 712ba9e9afc4b3d3d6fa81565ca36fe518915c01 upstream.

efi.runtime_version is erroneously being set to the value of the
vendor's firmware revision instead of that of the implemented EFI
specification. We can't deduce which EFI functions are available based
on the revision of the vendor's firmware since the version scheme is
likely to be unique to each vendor.

What we really need to know is the revision of the implemented EFI
specification, which is available in the EFI System Table header.

Signed-off-by: Matt Fleming 
Cc: Seiji Aguchi 
Cc: Matthew Garrett 
Signed-off-by: Greg Kroah-Hartman

efi, x86: Pass a proper identity mapping in efi_call_phys_prelog

2013-02-04T00:27:06+00:00

commit b8f2c21db390273c3eaf0e5308faeaeb1e233840 upstream.

Update efi_call_phys_prelog to install an identity mapping of all available
memory.  This corrects a bug on very large systems with more then 512 GB in
which bios would not be able to access addresses above not in the mapping.

The result is a crash that looks much like this.

BUG: unable to handle kernel paging request at 000000effd870020
IP: [<0000000078bce331>] 0x78bce330
PGD 0
Oops: 0000 [#1] SMP
Modules linked in:
CPU 0
Pid: 0, comm: swapper/0 Tainted: G        W    3.8.0-rc1-next-20121224-medusa_ntz+ #2 Intel Corp. Stoutland Platform
RIP: 0010:[<0000000078bce331>]  [<0000000078bce331>] 0x78bce330
RSP: 0000:ffffffff81601d28  EFLAGS: 00010006
RAX: 0000000078b80e18 RBX: 0000000000000004 RCX: 0000000000000004
RDX: 0000000078bcf958 RSI: 0000000000002400 RDI: 8000000000000000
RBP: 0000000078bcf760 R08: 000000effd870000 R09: 0000000000000000
R10: 0000000000000000 R11: 00000000000000c3 R12: 0000000000000030
R13: 000000effd870000 R14: 0000000000000000 R15: ffff88effd870000
FS:  0000000000000000(0000) GS:ffff88effe400000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000effd870020 CR3: 000000000160c000 CR4: 00000000000006b0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
Process swapper/0 (pid: 0, threadinfo ffffffff81600000, task ffffffff81614400)
Stack:
 0000000078b80d18 0000000000000004 0000000078bced7b ffff880078b81fff
 0000000000000000 0000000000000082 0000000078bce3a8 0000000000002400
 0000000060000202 0000000078b80da0 0000000078bce45d ffffffff8107cb5a
Call Trace:
 [] ? on_each_cpu+0x77/0x83
 [] ? change_page_attr_set_clr+0x32f/0x3ed
 [] ? efi_call4+0x46/0x80
 [] ? efi_enter_virtual_mode+0x1f5/0x305
 [] ? start_kernel+0x34a/0x3d2
 [] ? repair_env_string+0x60/0x60
 [] ? x86_64_start_reservations+0xba/0xc1
 [] ? early_idt_handlers+0x120/0x120
 [] ? x86_64_start_kernel+0x154/0x163
Code:  Bad RIP value.
RIP  [<0000000078bce331>] 0x78bce330
 RSP 
CR2: 000000effd870020
---[ end trace ead828934fef5eab ]---

Signed-off-by: Nathan Zimmer 
Cc: Thomas Gleixner 
Cc: Ingo Molnar 
Cc: "H. Peter Anvin" 
Signed-off-by: Robin Holt 
Signed-off-by: Matt Fleming 
Signed-off-by: Greg Kroah-Hartman

x86, efi: Fix 32-bit EFI handover protocol entry point

2013-02-04T00:27:06+00:00

commit f791620fa7517e1045742c475a7f005db9a634b8 upstream.

If the bootloader calls the EFI handover entry point as a standard function
call, then it'll have a return address on the stack. We need to pop that
before calling efi_main(), or the arguments will all be out of position on
the stack.

Signed-off-by: David Woodhouse 
Link: http://lkml.kernel.org/r/1358513837.2397.247.camel@shinybook.infradead.org
Signed-off-by: H. Peter Anvin 
Cc: Matt Fleming 
Signed-off-by: Greg Kroah-Hartman

x86, efi: Fix display detection in EFI boot stub

2013-02-04T00:27:06+00:00

commit 70a479cbe80296d3113e65cc2f713a5101061daf upstream.

When booting under OVMF we have precisely one GOP device, and it
implements the ConOut protocol.

We break out of the loop when we look at it... and then promptly abort
because 'first_gop' never gets set. We should set first_gop *before*
breaking out of the loop. Yes, it doesn't really mean "first" any more,
but that doesn't matter. It's only a flag to indicate that a suitable
GOP was found.

In fact, we'd do just as well to initialise 'width' to zero in this
function, then just check *that* instead of first_gop. But I'll do the
minimal fix for now (and for stable@).

Signed-off-by: David Woodhouse 
Link: http://lkml.kernel.org/r/1358513837.2397.247.camel@shinybook.infradead.org
Signed-off-by: H. Peter Anvin 
Cc: Matt Fleming 
Signed-off-by: Greg Kroah-Hartman

efi: Make 'efi_enabled' a function to query EFI facilities

2013-02-04T00:27:05+00:00

commit 83e68189745ad931c2afd45d8ee3303929233e7f upstream.

Originally 'efi_enabled' indicated whether a kernel was booted from
EFI firmware. Over time its semantics have changed, and it now
indicates whether or not we are booted on an EFI machine with
bit-native firmware, e.g. 64-bit kernel with 64-bit firmware.

The immediate motivation for this patch is the bug report at,

    https://bugs.launchpad.net/ubuntu-cdimage/+bug/1040557

which details how running a platform driver on an EFI machine that is
designed to run under BIOS can cause the machine to become
bricked. Also, the following report,

    https://bugzilla.kernel.org/show_bug.cgi?id=47121

details how running said driver can also cause Machine Check
Exceptions. Drivers need a new means of detecting whether they're
running on an EFI machine, as sadly the expression,

    if (!efi_enabled)

hasn't been a sufficient condition for quite some time.

Users actually want to query 'efi_enabled' for different reasons -
what they really want access to is the list of available EFI
facilities.

For instance, the x86 reboot code needs to know whether it can invoke
the ResetSystem() function provided by the EFI runtime services, while
the ACPI OSL code wants to know whether the EFI config tables were
mapped successfully. There are also checks in some of the platform
driver code to simply see if they're running on an EFI machine (which
would make it a bad idea to do BIOS-y things).

This patch is a prereq for the samsung-laptop fix patch.

Signed-off-by: Matt Fleming 
Cc: David Airlie 
Cc: Corentin Chary 
Cc: Matthew Garrett 
Cc: Dave Jiang 
Cc: Olof Johansson 
Cc: Peter Jones 
Cc: Colin Ian King 
Cc: Steve Langasek 
Cc: Tony Luck 
Cc: Konrad Rzeszutek Wilk 
Cc: Rafael J. Wysocki 
Signed-off-by: H. Peter Anvin 
Signed-off-by: Greg Kroah-Hartman

x86/msr: Add capabilities check

2013-02-04T00:27:05+00:00

commit c903f0456bc69176912dee6dd25c6a66ee1aed00 upstream.

At the moment the MSR driver only relies upon file system
checks. This means that anything as root with any capability set
can write to MSRs. Historically that wasn't very interesting but
on modern processors the MSRs are such that writing to them
provides several ways to execute arbitary code in kernel space.
Sample code and documentation on doing this is circulating and
MSR attacks are used on Windows 64bit rootkits already.

In the Linux case you still need to be able to open the device
file so the impact is fairly limited and reduces the security of
some capability and security model based systems down towards
that of a generic "root owns the box" setup.

Therefore they should require CAP_SYS_RAWIO to prevent an
elevation of capabilities. The impact of this is fairly minimal
on most setups because they don't have heavy use of
capabilities. Those using SELinux, SMACK or AppArmor rules might
want to consider if their rulesets on the MSR driver could be
tighter.

Signed-off-by: Alan Cox 
Cc: Linus Torvalds 
Cc: Andrew Morton 
Cc: Peter Zijlstra 
Signed-off-by: Ingo Molnar 
Signed-off-by: Greg Kroah-Hartman

s390/thp: implement pmdp_set_wrprotect()

2013-02-04T00:27:01+00:00

commit be3286507dab888d4aad9f91fd6ff5202b24cd5b upstream.

On s390, an architecture-specific implementation of the function
pmdp_set_wrprotect() is missing and the generic version is currently
being used. The generic version does not flush the tlb as it would be
needed on s390 when modifying an active pmd, which can lead to subtle
tlb errors on s390 when using transparent hugepages.

This patch adds an s390-specific implementation of pmdp_set_wrprotect()
including the missing tlb flush.

Signed-off-by: Gerald Schaefer 
Signed-off-by: Martin Schwidefsky 
Signed-off-by: Greg Kroah-Hartman

ARM: virt: simplify __hyp_stub_install epilog

2013-02-04T00:27:00+00:00

commit d01723479e6a6c70c83295f7847477a016d5e14a upstream.

__hyp_stub_install duplicates quite a bit of safe_svcmode_maskall
by forcing the CPU back to SVC. This is unnecessary, as
safe_svcmode_maskall is called just after.

Furthermore, the way we build SPSR_hyp is buggy as we fail to mask
the interrupts, leading to interesting behaviours on TC2 + UEFI.

The fix is to simply remove this code and rely on safe_svcmode_maskall
to do the right thing.

Reviewed-by: Dave Martin 
Reported-by: Harry Liebel 
Signed-off-by: Marc Zyngier 
Signed-off-by: Will Deacon 
Signed-off-by: Greg Kroah-Hartman

ARM: virt: boot secondary CPUs through the right entry point

2013-02-04T00:27:00+00:00

commit 6e484be1ccca3ea495db45900fd42aac8d49d754 upstream.

Secondary CPUs should use the __hyp_stub_install_secondary entry
point, so boot mode inconsistencies can be detected.

Acked-by: Dave Martin 
Reported-by: Ian Molton 
Signed-off-by: Marc Zyngier 
Signed-off-by: Will Deacon 
Signed-off-by: Greg Kroah-Hartman