linux-toradex.git/arch, branch v3.2.40 Linux kernel for Apalis and Colibri modules s390/timer: avoid overflow when programming clock comparator 2013-03-06T03:24:18+00:00 Heiko Carstens heiko.carstens@de.ibm.com 2013-01-29T08:16:28+00:00 903fba3bd1e99fbcac8a5e45e78059ce9357f7c1 commit d911e03d097bdc01363df5d81c43f69432eb785c upstream. Since ed4f209 "s390/time: fix sched_clock() overflow" a new helper function is used to avoid overflows when converting TOD format values to nanosecond values. The kvm interrupt code formerly however only worked by accident because of an overflow. It tried to program a timer that would expire in more than ~29 years. Because of the old TOD-to-nanoseconds overflow bug the real expiry value however was much smaller, but now it isn't anymore. This however triggers yet another bug in the function that programs the clock comparator s390_next_ktime(): if the absolute "expires" value is after 2042 this will result in an overflow and the programmed value is lower than the current TOD value which immediatly triggers a clock comparator (= timer) interrupt. Since the timer isn't expired it will be programmed immediately again and so on... the result is a dead system. To fix this simply program the maximum possible value if an overflow is detected. Reported-by: Christian Borntraeger <borntraeger@de.ibm.com> Tested-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Ben Hutchings <ben@decadent.org.uk> 
commit d911e03d097bdc01363df5d81c43f69432eb785c upstream.

Since ed4f209 "s390/time: fix sched_clock() overflow" a new helper function
is used to avoid overflows when converting TOD format values to nanosecond
values.
The kvm interrupt code formerly however only worked by accident because of
an overflow. It tried to program a timer that would expire in more than ~29
years. Because of the old TOD-to-nanoseconds overflow bug the real expiry
value however was much smaller, but now it isn't anymore.
This however triggers yet another bug in the function that programs the clock
comparator s390_next_ktime(): if the absolute "expires" value is after 2042
this will result in an overflow and the programmed value is lower than the
current TOD value which immediatly triggers a clock comparator (= timer)
interrupt.
Since the timer isn't expired it will be programmed immediately again and so
on... the result is a dead system.
To fix this simply program the maximum possible value if an overflow is
detected.

Reported-by: Christian Borntraeger <borntraeger@de.ibm.com>
Tested-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
x86: Make sure we can boot in the case the BDA contains pure garbage 2013-03-06T03:24:14+00:00 H. Peter Anvin hpa@linux.intel.com 2013-02-27T20:46:40+00:00 c2581d3df8552f9237245f85338f767c5a22660f 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 <dvhart@linux.intel.com> Signed-off-by: H. Peter Anvin <hpa@linux.intel.com> Cc: Matt Fleming <matt.fleming@intel.com> Link: http://lkml.kernel.org/n/tip-oebml055yyfm8yxmria09rja@git.kernel.org Signed-off-by: Ben Hutchings <ben@decadent.org.uk> 
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 <dvhart@linux.intel.com>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Cc: Matt Fleming <matt.fleming@intel.com>
Link: http://lkml.kernel.org/n/tip-oebml055yyfm8yxmria09rja@git.kernel.org
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
powerpc/kexec: Disable hard IRQ before kexec 2013-03-06T03:24:11+00:00 Phileas Fogg phileas-fogg@mail.ru 2013-02-22T23:32:19+00:00 819a56e867d8e4ebe87060eaf576c0032a8963c2 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 <phileas-fogg@mail.ru> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Ben Hutchings <ben@decadent.org.uk> 
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 <phileas-fogg@mail.ru>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
x86, efi: Make "noefi" really disable EFI runtime serivces 2013-03-06T03:24:08+00:00 Matt Fleming matt.fleming@intel.com 2013-02-20T20:36:12+00:00 1a116473beaf0b6c1ca6bfe18967094ce513f029 commit fb834c7acc5e140cf4f9e86da93a66de8c0514da upstream. commit 1de63d60cd5b ("efi: Clear EFI_RUNTIME_SERVICES rather than EFI_BOOT by "noefi" boot parameter") attempted to make "noefi" true to its documentation and disable EFI runtime services to prevent the bricking bug described in commit e0094244e41c ("samsung-laptop: Disable on EFI hardware"). However, it's not possible to clear EFI_RUNTIME_SERVICES from an early param function because EFI_RUNTIME_SERVICES is set in efi_init() *after* parse_early_param(). This resulted in "noefi" effectively becoming a no-op and no longer providing users with a way to disable EFI, which is bad for those users that have buggy machines. Reported-by: Walt Nelson Jr <walt0924@gmail.com> Cc: Satoru Takeuchi <takeuchi_satoru@jp.fujitsu.com> Signed-off-by: Matt Fleming <matt.fleming@intel.com> Link: http://lkml.kernel.org/r/1361392572-25657-1-git-send-email-matt@console-pimps.org Signed-off-by: H. Peter Anvin <hpa@linux.intel.com> [bwh: Backported to 3.2: efi_runtime_init() is not a separate function, so put a whole set of statements in an if (!disable_runtime) block] Signed-off-by: Ben Hutchings <ben@decadent.org.uk> 
commit fb834c7acc5e140cf4f9e86da93a66de8c0514da upstream.

commit 1de63d60cd5b ("efi: Clear EFI_RUNTIME_SERVICES rather than
EFI_BOOT by "noefi" boot parameter") attempted to make "noefi" true to
its documentation and disable EFI runtime services to prevent the
bricking bug described in commit e0094244e41c ("samsung-laptop:
Disable on EFI hardware"). However, it's not possible to clear
EFI_RUNTIME_SERVICES from an early param function because
EFI_RUNTIME_SERVICES is set in efi_init() *after* parse_early_param().

This resulted in "noefi" effectively becoming a no-op and no longer
providing users with a way to disable EFI, which is bad for those
users that have buggy machines.

Reported-by: Walt Nelson Jr <walt0924@gmail.com>
Cc: Satoru Takeuchi <takeuchi_satoru@jp.fujitsu.com>
Signed-off-by: Matt Fleming <matt.fleming@intel.com>
Link: http://lkml.kernel.org/r/1361392572-25657-1-git-send-email-matt@console-pimps.org
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
[bwh: Backported to 3.2: efi_runtime_init() is not a separate function,
 so put a whole set of statements in an if (!disable_runtime) block]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
xen: Send spinlock IPI to all waiters 2013-03-06T03:24:08+00:00 Stefan Bader stefan.bader@canonical.com 2013-02-15T08:48:52+00:00 7afb6c33d409713fd204557c183bbe47c4983ea8 commit 76eaca031f0af2bb303e405986f637811956a422 upstream. There is a loophole between Xen's current implementation of pv-spinlocks and the scheduler. This was triggerable through a testcase until v3.6 changed the TLB flushing code. The problem potentially is still there just not observable in the same way. What could happen was (is): 1. CPU n tries to schedule task x away and goes into a slow wait for the runq lock of CPU n-# (must be one with a lower number). 2. CPU n-#, while processing softirqs, tries to balance domains and goes into a slow wait for its own runq lock (for updating some records). Since this is a spin_lock_irqsave in softirq context, interrupts will be re-enabled for the duration of the poll_irq hypercall used by Xen. 3. Before the runq lock of CPU n-# is unlocked, CPU n-1 receives an interrupt (e.g. endio) and when processing the interrupt, tries to wake up task x. But that is in schedule and still on_cpu, so try_to_wake_up goes into a tight loop. 4. The runq lock of CPU n-# gets unlocked, but the message only gets sent to the first waiter, which is CPU n-# and that is busily stuck. 5. CPU n-# never returns from the nested interruption to take and release the lock because the scheduler uses a busy wait. And CPU n never finishes the task migration because the unlock notification only went to CPU n-#. To avoid this and since the unlocking code has no real sense of which waiter is best suited to grab the lock, just send the IPI to all of them. This causes the waiters to return from the hyper- call (those not interrupted at least) and do active spinlocking. BugLink: http://bugs.launchpad.net/bugs/1011792 Acked-by: Jan Beulich <JBeulich@suse.com> Signed-off-by: Stefan Bader <stefan.bader@canonical.com> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Signed-off-by: Ben Hutchings <ben@decadent.org.uk> 
commit 76eaca031f0af2bb303e405986f637811956a422 upstream.

There is a loophole between Xen's current implementation of
pv-spinlocks and the scheduler. This was triggerable through
a testcase until v3.6 changed the TLB flushing code. The
problem potentially is still there just not observable in the
same way.

What could happen was (is):

1. CPU n tries to schedule task x away and goes into a slow
   wait for the runq lock of CPU n-# (must be one with a lower
   number).
2. CPU n-#, while processing softirqs, tries to balance domains
   and goes into a slow wait for its own runq lock (for updating
   some records). Since this is a spin_lock_irqsave in softirq
   context, interrupts will be re-enabled for the duration of
   the poll_irq hypercall used by Xen.
3. Before the runq lock of CPU n-# is unlocked, CPU n-1 receives
   an interrupt (e.g. endio) and when processing the interrupt,
   tries to wake up task x. But that is in schedule and still
   on_cpu, so try_to_wake_up goes into a tight loop.
4. The runq lock of CPU n-# gets unlocked, but the message only
   gets sent to the first waiter, which is CPU n-# and that is
   busily stuck.
5. CPU n-# never returns from the nested interruption to take and
   release the lock because the scheduler uses a busy wait.
   And CPU n never finishes the task migration because the unlock
   notification only went to CPU n-#.

To avoid this and since the unlocking code has no real sense of
which waiter is best suited to grab the lock, just send the IPI
to all of them. This causes the waiters to return from the hyper-
call (those not interrupted at least) and do active spinlocking.

BugLink: http://bugs.launchpad.net/bugs/1011792

Acked-by: Jan Beulich <JBeulich@suse.com>
Signed-off-by: Stefan Bader <stefan.bader@canonical.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
ARM: w90x900: fix legacy assembly syntax 2013-03-06T03:24:00+00:00 Arnd Bergmann arnd@arndb.de 2013-01-14T12:49:02+00:00 ee0a25ab1c315dbd8483b03a5ecd661e130ff18f commit fa5ce5f94c0f2bfa41ba68d2d2524298e1fc405e upstream. New ARM binutils don't allow extraneous whitespace inside of brackets, which causes this error on all mach-w90x900 defconfigs: arch/arm/kernel/entry-armv.S: Assembler messages: arch/arm/kernel/entry-armv.S:214: Error: ARM register expected -- `ldr r0,[ r6,#(0x10C)]' arch/arm/kernel/entry-armv.S:214: Error: ARM register expected -- `ldr r0,[ r6,#(0x110)]' arch/arm/kernel/entry-armv.S:430: Error: ARM register expected -- `ldr r0,[ r6,#(0x10C)]' arch/arm/kernel/entry-armv.S:430: Error: ARM register expected -- `ldr r0,[ r6,#(0x110)]' This removes the whitespace in order to build the kernel again. Signed-off-by: Arnd Bergmann <arnd@arndb.de> Cc: Wan ZongShun <mcuos.com@gmail.com> Signed-off-by: Ben Hutchings <ben@decadent.org.uk> 
commit fa5ce5f94c0f2bfa41ba68d2d2524298e1fc405e upstream.

New ARM binutils don't allow extraneous whitespace inside
of brackets, which causes this error on all mach-w90x900
defconfigs:

arch/arm/kernel/entry-armv.S: Assembler messages:
arch/arm/kernel/entry-armv.S:214: Error: ARM register expected -- `ldr r0,[ r6,#(0x10C)]'
arch/arm/kernel/entry-armv.S:214: Error: ARM register expected -- `ldr r0,[ r6,#(0x110)]'
arch/arm/kernel/entry-armv.S:430: Error: ARM register expected -- `ldr r0,[ r6,#(0x10C)]'
arch/arm/kernel/entry-armv.S:430: Error: ARM register expected -- `ldr r0,[ r6,#(0x110)]'

This removes the whitespace in order to build the kernel
again.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Cc: Wan ZongShun <mcuos.com@gmail.com>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
ARM: samsung: fix assembly syntax for new gas 2013-03-06T03:23:59+00:00 Arnd Bergmann arnd@arndb.de 2013-01-08T21:58:31+00:00 70c469761ceedc66693e010da610f1f05bdfaf4b commit 2815774bb38445006074e16251b9ef5123bdc616 upstream. Recent assembler versions complain about extraneous whitespace inside [] brackets. This fixes all of these instances for the samsung platforms. We should backport this to all kernels that might need to be built with new binutils. arch/arm/kernel/entry-armv.S: Assembler messages: arch/arm/kernel/entry-armv.S:214: Error: ARM register expected -- `ldr r2,[ r6,#(0x10)]' arch/arm/kernel/entry-armv.S:214: Error: ARM register expected -- `ldr r0,[ r6,#(0x14)]' arch/arm/kernel/entry-armv.S:430: Error: ARM register expected -- `ldr r2,[ r6,#(0x10)]' arch/arm/kernel/entry-armv.S:430: Error: ARM register expected -- `ldr r0,[ r6,#(0x14)]' arch/arm/mach-s3c24xx/sleep-s3c2410.S: Assembler messages: arch/arm/mach-s3c24xx/sleep-s3c2410.S:48: Error: ARM register expected -- `ldr r7,[ r4 ]' arch/arm/mach-s3c24xx/sleep-s3c2410.S:49: Error: ARM register expected -- `ldr r8,[ r5 ]' arch/arm/mach-s3c24xx/sleep-s3c2410.S:50: Error: ARM register expected -- `ldr r9,[ r6 ]' arch/arm/mach-s3c24xx/sleep-s3c2410.S:64: Error: ARM register expected -- `streq r7,[ r4 ]' arch/arm/mach-s3c24xx/sleep-s3c2410.S:65: Error: ARM register expected -- `streq r8,[ r5 ]' arch/arm/mach-s3c24xx/sleep-s3c2410.S:66: Error: ARM register expected -- `streq r9,[ r6 ]' arch/arm/kernel/debug.S: Assembler messages: arch/arm/kernel/debug.S:83: Error: ARM register expected -- `ldr r2,[ r2,#((0x0B0)+(((0x56000000)-(0x50000000))+(0xF6000000+(0x01000000))))-((0)+(((0x56000000)-(0x50000000))+(0xF6000000+(0x01000000))))]' arch/arm/kernel/debug.S:83: Error: ARM register expected -- `ldr r2,[ r3,#(0x18)]' arch/arm/kernel/debug.S:85: Error: ARM register expected -- `ldr r2,[ r2,#((0x0B0)+(((0x56000000)-(0x50000000))+(0xF6000000+(0x01000000))))-((0)+(((0x56000000)-(0x50000000))+(0xF6000000+(0x01000000))))]' arch/arm/kernel/debug.S:85: Error: ARM register expected -- `ldr r2,[ r3,#(0x18)]' arch/arm/mach-s3c24xx/pm-h1940.S: Assembler messages: arch/arm/mach-s3c24xx/pm-h1940.S:33: Error: ARM register expected -- `ldr pc,[ r0,#((0x0B8)+(((0x56000000)-(0x50000000))+(0xF6000000+(0x01000000))))-(((0x56000000)-(0x50000000))+(0xF6000000+(0x01000000)))]' arch/arm/mach-s3c24xx/sleep-s3c2412.S: Assembler messages: arch/arm/mach-s3c24xx/sleep-s3c2412.S:60: Error: ARM register expected -- `ldrne r9,[ r1 ]' arch/arm/mach-s3c24xx/sleep-s3c2412.S:61: Error: ARM register expected -- `strne r9,[ r1 ]' arch/arm/mach-s3c24xx/sleep-s3c2412.S:62: Error: ARM register expected -- `ldrne r9,[ r2 ]' arch/arm/mach-s3c24xx/sleep-s3c2412.S:63: Error: ARM register expected -- `strne r9,[ r2 ]' arch/arm/mach-s3c24xx/sleep-s3c2412.S:64: Error: ARM register expected -- `ldrne r9,[ r3 ]' arch/arm/mach-s3c24xx/sleep-s3c2412.S:65: Error: ARM register expected -- `strne r9,[ r3 ]' arch/arm/kernel/debug.S:83: Error: ARM register expected -- `ldr r2,[ r3,#(0x08)]' arch/arm/kernel/debug.S:83: Error: ARM register expected -- `ldr r2,[ r3,#(0x18)]' arch/arm/kernel/debug.S:83: Error: ARM register expected -- `ldr r2,[ r3,#(0x10)]' arch/arm/kernel/debug.S:85: Error: ARM register expected -- `ldr r2,[ r3,#(0x08)]' arch/arm/kernel/debug.S:85: Error: ARM register expected -- `ldr r2,[ r3,#(0x18)]' arch/arm/kernel/debug.S:85: Error: ARM register expected -- `ldr r2,[ r3,#(0x10)]' Signed-off-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Kukjin Kim <kgene.kim@samsung.com> Cc: Ben Dooks <ben-linux@fluff.org> [bwh: Backported to 3.2: adjust filenames] Signed-off-by: Ben Hutchings <ben@decadent.org.uk> 
commit 2815774bb38445006074e16251b9ef5123bdc616 upstream.

Recent assembler versions complain about extraneous
whitespace inside [] brackets. This fixes all of
these instances for the samsung platforms. We should
backport this to all kernels that might need to
be built with new binutils.

arch/arm/kernel/entry-armv.S: Assembler messages:
arch/arm/kernel/entry-armv.S:214: Error: ARM register expected -- `ldr r2,[ r6,#(0x10)]'
arch/arm/kernel/entry-armv.S:214: Error: ARM register expected -- `ldr r0,[ r6,#(0x14)]'
arch/arm/kernel/entry-armv.S:430: Error: ARM register expected -- `ldr r2,[ r6,#(0x10)]'
arch/arm/kernel/entry-armv.S:430: Error: ARM register expected -- `ldr r0,[ r6,#(0x14)]'
arch/arm/mach-s3c24xx/sleep-s3c2410.S: Assembler messages:
arch/arm/mach-s3c24xx/sleep-s3c2410.S:48: Error: ARM register expected -- `ldr r7,[ r4 ]'
arch/arm/mach-s3c24xx/sleep-s3c2410.S:49: Error: ARM register expected -- `ldr r8,[ r5 ]'
arch/arm/mach-s3c24xx/sleep-s3c2410.S:50: Error: ARM register expected -- `ldr r9,[ r6 ]'
arch/arm/mach-s3c24xx/sleep-s3c2410.S:64: Error: ARM register expected -- `streq r7,[ r4 ]'
arch/arm/mach-s3c24xx/sleep-s3c2410.S:65: Error: ARM register expected -- `streq r8,[ r5 ]'
arch/arm/mach-s3c24xx/sleep-s3c2410.S:66: Error: ARM register expected -- `streq r9,[ r6 ]'
arch/arm/kernel/debug.S: Assembler messages:
arch/arm/kernel/debug.S:83: Error: ARM register expected -- `ldr r2,[ r2,#((0x0B0)+(((0x56000000)-(0x50000000))+(0xF6000000+(0x01000000))))-((0)+(((0x56000000)-(0x50000000))+(0xF6000000+(0x01000000))))]'
arch/arm/kernel/debug.S:83: Error: ARM register expected -- `ldr r2,[ r3,#(0x18)]'
arch/arm/kernel/debug.S:85: Error: ARM register expected -- `ldr r2,[ r2,#((0x0B0)+(((0x56000000)-(0x50000000))+(0xF6000000+(0x01000000))))-((0)+(((0x56000000)-(0x50000000))+(0xF6000000+(0x01000000))))]'
arch/arm/kernel/debug.S:85: Error: ARM register expected -- `ldr r2,[ r3,#(0x18)]'
arch/arm/mach-s3c24xx/pm-h1940.S: Assembler messages:
arch/arm/mach-s3c24xx/pm-h1940.S:33: Error: ARM register expected -- `ldr pc,[ r0,#((0x0B8)+(((0x56000000)-(0x50000000))+(0xF6000000+(0x01000000))))-(((0x56000000)-(0x50000000))+(0xF6000000+(0x01000000)))]'
arch/arm/mach-s3c24xx/sleep-s3c2412.S: Assembler messages:
arch/arm/mach-s3c24xx/sleep-s3c2412.S:60: Error: ARM register expected -- `ldrne r9,[ r1 ]'
arch/arm/mach-s3c24xx/sleep-s3c2412.S:61: Error: ARM register expected -- `strne r9,[ r1 ]'
arch/arm/mach-s3c24xx/sleep-s3c2412.S:62: Error: ARM register expected -- `ldrne r9,[ r2 ]'
arch/arm/mach-s3c24xx/sleep-s3c2412.S:63: Error: ARM register expected -- `strne r9,[ r2 ]'
arch/arm/mach-s3c24xx/sleep-s3c2412.S:64: Error: ARM register expected -- `ldrne r9,[ r3 ]'
arch/arm/mach-s3c24xx/sleep-s3c2412.S:65: Error: ARM register expected -- `strne r9,[ r3 ]'
arch/arm/kernel/debug.S:83: Error: ARM register expected -- `ldr r2,[ r3,#(0x08)]'
arch/arm/kernel/debug.S:83: Error: ARM register expected -- `ldr r2,[ r3,#(0x18)]'
arch/arm/kernel/debug.S:83: Error: ARM register expected -- `ldr r2,[ r3,#(0x10)]'
arch/arm/kernel/debug.S:85: Error: ARM register expected -- `ldr r2,[ r3,#(0x08)]'
arch/arm/kernel/debug.S:85: Error: ARM register expected -- `ldr r2,[ r3,#(0x18)]'
arch/arm/kernel/debug.S:85: Error: ARM register expected -- `ldr r2,[ r3,#(0x10)]'

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Kukjin Kim <kgene.kim@samsung.com>
Cc: Ben Dooks <ben-linux@fluff.org>
[bwh: Backported to 3.2: adjust filenames]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
efi: Clear EFI_RUNTIME_SERVICES rather than EFI_BOOT by "noefi" boot parameter 2013-03-06T03:23:59+00:00 Satoru Takeuchi takeuchi_satoru@jp.fujitsu.com 2013-02-14T00:12:52+00:00 ce75086eb205efa219fb9975ba53bdc1a1390839 commit 1de63d60cd5b0d33a812efa455d5933bf1564a51 upstream. There was a serious problem in samsung-laptop that its platform driver is designed to run under BIOS and running under EFI can cause the machine to become bricked or can cause Machine Check Exceptions. Discussion about this problem: https://bugs.launchpad.net/ubuntu-cdimage/+bug/1040557 https://bugzilla.kernel.org/show_bug.cgi?id=47121 The patches to fix this problem: efi: Make 'efi_enabled' a function to query EFI facilities 83e68189745ad931c2afd45d8ee3303929233e7f samsung-laptop: Disable on EFI hardware e0094244e41c4d0c7ad69920681972fc45d8ce34 Unfortunately this problem comes back again if users specify "noefi" option. This parameter clears EFI_BOOT and that driver continues to run even if running under EFI. Refer to the document, this parameter should clear EFI_RUNTIME_SERVICES instead. Documentation/kernel-parameters.txt: =============================================================================== ... noefi [X86] Disable EFI runtime services support. ... =============================================================================== Documentation/x86/x86_64/uefi.txt: =============================================================================== ... - If some or all EFI runtime services don't work, you can try following kernel command line parameters to turn off some or all EFI runtime services. noefi turn off all EFI runtime services ... =============================================================================== Signed-off-by: Satoru Takeuchi <takeuchi_satoru@jp.fujitsu.com> Link: http://lkml.kernel.org/r/511C2C04.2070108@jp.fujitsu.com Cc: Matt Fleming <matt.fleming@intel.com> Signed-off-by: H. Peter Anvin <hpa@linux.intel.com> Signed-off-by: Ben Hutchings <ben@decadent.org.uk> 
commit 1de63d60cd5b0d33a812efa455d5933bf1564a51 upstream.

There was a serious problem in samsung-laptop that its platform driver is
designed to run under BIOS and running under EFI can cause the machine to
become bricked or can cause Machine Check Exceptions.

    Discussion about this problem:
    https://bugs.launchpad.net/ubuntu-cdimage/+bug/1040557
    https://bugzilla.kernel.org/show_bug.cgi?id=47121

    The patches to fix this problem:
    efi: Make 'efi_enabled' a function to query EFI facilities
    83e68189745ad931c2afd45d8ee3303929233e7f

    samsung-laptop: Disable on EFI hardware
    e0094244e41c4d0c7ad69920681972fc45d8ce34

Unfortunately this problem comes back again if users specify "noefi" option.
This parameter clears EFI_BOOT and that driver continues to run even if running
under EFI. Refer to the document, this parameter should clear
EFI_RUNTIME_SERVICES instead.

Documentation/kernel-parameters.txt:
===============================================================================
...
	noefi		[X86] Disable EFI runtime services support.
...
===============================================================================

Documentation/x86/x86_64/uefi.txt:
===============================================================================
...
- If some or all EFI runtime services don't work, you can try following
  kernel command line parameters to turn off some or all EFI runtime
  services.
	noefi		turn off all EFI runtime services
...
===============================================================================

Signed-off-by: Satoru Takeuchi <takeuchi_satoru@jp.fujitsu.com>
Link: http://lkml.kernel.org/r/511C2C04.2070108@jp.fujitsu.com
Cc: Matt Fleming <matt.fleming@intel.com>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
x86/mm: Check if PUD is large when validating a kernel address 2013-03-06T03:23:56+00:00 Mel Gorman mgorman@suse.de 2013-02-11T14:52:36+00:00 7ee959779fbb0ac92d264c88e53eac3628cfcc1f commit 0ee364eb316348ddf3e0dfcd986f5f13f528f821 upstream. A user reported the following oops when a backup process reads /proc/kcore: BUG: unable to handle kernel paging request at ffffbb00ff33b000 IP: [<ffffffff8103157e>] kern_addr_valid+0xbe/0x110 [...] Call Trace: [<ffffffff811b8aaa>] read_kcore+0x17a/0x370 [<ffffffff811ad847>] proc_reg_read+0x77/0xc0 [<ffffffff81151687>] vfs_read+0xc7/0x130 [<ffffffff811517f3>] sys_read+0x53/0xa0 [<ffffffff81449692>] system_call_fastpath+0x16/0x1b Investigation determined that the bug triggered when reading system RAM at the 4G mark. On this system, that was the first address using 1G pages for the virt->phys direct mapping so the PUD is pointing to a physical address, not a PMD page. The problem is that the page table walker in kern_addr_valid() is not checking pud_large() and treats the physical address as if it was a PMD. If it happens to look like pmd_none then it'll silently fail, probably returning zeros instead of real data. If the data happens to look like a present PMD though, it will be walked resulting in the oops above. This patch adds the necessary pud_large() check. Unfortunately the problem was not readily reproducible and now they are running the backup program without accessing /proc/kcore so the patch has not been validated but I think it makes sense. Signed-off-by: Mel Gorman <mgorman@suse.de> Reviewed-by: Rik van Riel <riel@redhat.coM> Reviewed-by: Michal Hocko <mhocko@suse.cz> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Cc: linux-mm@kvack.org Link: http://lkml.kernel.org/r/20130211145236.GX21389@suse.de Signed-off-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Ben Hutchings <ben@decadent.org.uk> 
commit 0ee364eb316348ddf3e0dfcd986f5f13f528f821 upstream.

A user reported the following oops when a backup process reads
/proc/kcore:

 BUG: unable to handle kernel paging request at ffffbb00ff33b000
 IP: [<ffffffff8103157e>] kern_addr_valid+0xbe/0x110
 [...]

 Call Trace:
  [<ffffffff811b8aaa>] read_kcore+0x17a/0x370
  [<ffffffff811ad847>] proc_reg_read+0x77/0xc0
  [<ffffffff81151687>] vfs_read+0xc7/0x130
  [<ffffffff811517f3>] sys_read+0x53/0xa0
  [<ffffffff81449692>] system_call_fastpath+0x16/0x1b

Investigation determined that the bug triggered when reading
system RAM at the 4G mark. On this system, that was the first
address using 1G pages for the virt->phys direct mapping so the
PUD is pointing to a physical address, not a PMD page.

The problem is that the page table walker in kern_addr_valid() is
not checking pud_large() and treats the physical address as if
it was a PMD.  If it happens to look like pmd_none then it'll
silently fail, probably returning zeros instead of real data. If
the data happens to look like a present PMD though, it will be
walked resulting in the oops above.

This patch adds the necessary pud_large() check.

Unfortunately the problem was not readily reproducible and now
they are running the backup program without accessing
/proc/kcore so the patch has not been validated but I think it
makes sense.

Signed-off-by: Mel Gorman <mgorman@suse.de>
Reviewed-by: Rik van Riel <riel@redhat.coM>
Reviewed-by: Michal Hocko <mhocko@suse.cz>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: linux-mm@kvack.org
Link: http://lkml.kernel.org/r/20130211145236.GX21389@suse.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
x86: Hyper-V: register clocksource only if its advertised 2013-03-06T03:23:56+00:00 Olaf Hering [mailto:olaf@aepfle.de] 2013-02-04T01:22:37+00:00 12324875d79c23a13bbf66390b595a84337dc8d7 commit 32068f6527b8f1822a30671dedaf59c567325026 upstream. Enable hyperv_clocksource only if its advertised as a feature. XenServer 6 returns the signature which is checked in ms_hyperv_platform(), but it does not offer all features. Currently the clocksource is enabled unconditionally in ms_hyperv_init_platform(), and the result is a hanging guest. Hyper-V spec Bit 1 indicates the availability of Partition Reference Counter. Register the clocksource only if this bit is set. The guest in question prints this in dmesg: [ 0.000000] Hypervisor detected: Microsoft HyperV [ 0.000000] HyperV: features 0x70, hints 0x0 This bug can be reproduced easily be setting 'viridian=1' in a HVM domU .cfg file. A workaround without this patch is to boot the HVM guest with 'clocksource=jiffies'. Signed-off-by: Olaf Hering <olaf@aepfle.de> Link: http://lkml.kernel.org/r/1359940959-32168-1-git-send-email-kys@microsoft.com Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> Cc: Greg KH <gregkh@linuxfoundation.org> Signed-off-by: H. Peter Anvin <hpa@linux.intel.com> Signed-off-by: Ben Hutchings <ben@decadent.org.uk> 
commit 32068f6527b8f1822a30671dedaf59c567325026 upstream.

Enable hyperv_clocksource only if its advertised as a feature.
XenServer 6 returns the signature which is checked in
ms_hyperv_platform(), but it does not offer all features. Currently the
clocksource is enabled unconditionally in ms_hyperv_init_platform(), and
the result is a hanging guest.

Hyper-V spec Bit 1 indicates the availability of Partition Reference
Counter.  Register the clocksource only if this bit is set.

The guest in question prints this in dmesg:
 [    0.000000] Hypervisor detected: Microsoft HyperV
 [    0.000000] HyperV: features 0x70, hints 0x0

This bug can be reproduced easily be setting 'viridian=1' in a HVM domU
.cfg file. A workaround without this patch is to boot the HVM guest with
'clocksource=jiffies'.

Signed-off-by: Olaf Hering <olaf@aepfle.de>
Link: http://lkml.kernel.org/r/1359940959-32168-1-git-send-email-kys@microsoft.com
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Cc: Greg KH <gregkh@linuxfoundation.org>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>