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  1. Mar 21, 2013
  3. Mar 17, 2013
    • Linus Torvalds's avatar
      perf,x86: fix wrmsr_on_cpu() warning on suspend/resume · 2a6e06b2
      Linus Torvalds authored 
      

Commit 1d9d8639 ("perf,x86: fix kernel crash with PEBS/BTS after
suspend/resume") fixed a crash when doing PEBS performance profiling
after resuming, but in using init_debug_store_on_cpu() to restore the
DS_AREA mtrr it also resulted in a new WARN_ON() triggering.

init_debug_store_on_cpu() uses "wrmsr_on_cpu()", which in turn uses CPU
cross-calls to do the MSR update.  Which is not really valid at the
early resume stage, and the warning is quite reasonable.  Now, it all
happens to _work_, for the simple reason that smp_call_function_single()
ends up just doing the call directly on the CPU when the CPU number
matches, but we really should just do the wrmsr() directly instead.

This duplicates the wrmsr() logic, but hopefully we can just remove the
wrmsr_on_cpu() version eventually.

Reported-and-tested-by: default avatarParag Warudkar <parag.lkml@gmail.com>
Cc: stable@vger.kernel.org
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      2a6e06b2
  5. Mar 15, 2013
  7. Mar 14, 2013
  9. Mar 13, 2013
    • David Howells's avatar
      UAPI: fix endianness conditionals in M32R's asm/stat.h · 415586c9
      David Howells authored 
      

In the UAPI header files, __BIG_ENDIAN and __LITTLE_ENDIAN must be
compared against __BYTE_ORDER in preprocessor conditionals where these are
exposed to userspace (that is they're not inside __KERNEL__ conditionals).

However, in the main kernel the norm is to check for
"defined(__XXX_ENDIAN)" rather than comparing against __BYTE_ORDER and
this has incorrectly leaked into the userspace headers.

The definition of struct stat64 in M32R's asm/stat.h is wrong in this way.
 Note that userspace will likely interpret the field order incorrectly as
the big-endian variant on little-endian machines - depending on header
inclusion order.

[!!!] NOTE [!!!]  This patch may adversely change the userspace API.  It might
be better to fix the ordering of st_blocks and __pad4 in struct stat64.

Signed-off-by: default avatarDavid Howells <dhowells@redhat.com>
Cc: Hirokazu Takata <takata@linux-m32r.org>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      415586c9
    • Jonas Bonn's avatar
      openrisc: remove HAVE_VIRT_TO_BUS · 6af60951
      Jonas Bonn authored 
      

The OpenRISC arch doesn't actually have the virt_to_bus methods

Signed-off-by: default avatarJonas Bonn <jonas@southpole.se>
      6af60951
    • Jonas Bonn's avatar
      openrisc: require gpiolib · d4cb776f
      Jonas Bonn authored 
      

The recent move to GPIO descriptors breaks the OpenRISC build.  Requiring
gpiolib resolves this; using gpiolib exclusively is also the recommended
way forward for all arches by the developers working on these GPIO changes.
The non-gpiolib implementation for OpenRISC never worked anyway...

Signed-off-by: default avatarJonas Bonn <jonas@southpole.se>
      d4cb776f
  11. Mar 12, 2013
  13. Mar 11, 2013
  15. Mar 08, 2013
  17. Mar 07, 2013
    • Dave Hansen's avatar
      x86: Do not try to sync identity map for non-mapped pages · 60f583d5
      Dave Hansen authored 
      kernel_map_sync_memtype() is called from a variety of contexts.  The
pat.c code that calls it seems to ensure that it is not called for
non-ram areas by checking via pat_pagerange_is_ram().  It is important
that it only be called on the actual identity map because there *IS*
no map to sync for highmem pages, or for memory holes.

The ioremap.c uses are not as careful as those from pat.c, and call
kernel_map_sync_memtype() on PCI space which is in the middle of the
kernel identity map _range_, but is not actually mapped.

This patch adds a check to kernel_map_sync_memtype() which probably
duplicates some of the checks already in pat.c.  But, it is necessary
for the ioremap.c uses and shouldn't hurt other callers.

I have reproduced this bug and this patch fixes it for me and the
original bug reporter:

	https://lkml.org/lkml/2013/2/5/396



Signed-off-by: default avatarDave Hansen <dave@linux.vnet.ibm.com>
Link: http://lkml.kernel.org/r/20130307163151.D9B58C4E@kernel.stglabs.ibm.com


Signed-off-by: default avatarDave Hansen <dave@sr71.net>
Tested-by: default avatarTetsuo Handa <penguin-kernel@i-love.sakura.ne.jp>
Signed-off-by: default avatarH. Peter Anvin <hpa@zytor.com>
      60f583d5
    • Ivan Djelic's avatar
      ARM: 7668/1: fix memset-related crashes caused by recent GCC (4.7.2) optimizations · 455bd4c4
      Ivan Djelic authored 
      

Recent GCC versions (e.g. GCC-4.7.2) perform optimizations based on
assumptions about the implementation of memset and similar functions.
The current ARM optimized memset code does not return the value of
its first argument, as is usually expected from standard implementations.

For instance in the following function:

void debug_mutex_lock_common(struct mutex *lock, struct mutex_waiter *waiter)
{
	memset(waiter, MUTEX_DEBUG_INIT, sizeof(*waiter));
	waiter->magic = waiter;
	INIT_LIST_HEAD(&waiter->list);
}

compiled as:

800554d0 <debug_mutex_lock_common>:
800554d0:       e92d4008        push    {r3, lr}
800554d4:       e1a00001        mov     r0, r1
800554d8:       e3a02010        mov     r2, #16 ; 0x10
800554dc:       e3a01011        mov     r1, #17 ; 0x11
800554e0:       eb04426e        bl      80165ea0 <memset>
800554e4:       e1a03000        mov     r3, r0
800554e8:       e583000c        str     r0, [r3, #12]
800554ec:       e5830000        str     r0, [r3]
800554f0:       e5830004        str     r0, [r3, #4]
800554f4:       e8bd8008        pop     {r3, pc}

GCC assumes memset returns the value of pointer 'waiter' in register r0; causing
register/memory corruptions.

This patch fixes the return value of the assembly version of memset.
It adds a 'mov' instruction and merges an additional load+store into
existing load/store instructions.
For ease of review, here is a breakdown of the patch into 4 simple steps:

Step 1
======
Perform the following substitutions:
ip -> r8, then
r0 -> ip,
and insert 'mov ip, r0' as the first statement of the function.
At this point, we have a memset() implementation returning the proper result,
but corrupting r8 on some paths (the ones that were using ip).

Step 2
======
Make sure r8 is saved and restored when (! CALGN(1)+0) == 1:

save r8:
-       str     lr, [sp, #-4]!
+       stmfd   sp!, {r8, lr}

and restore r8 on both exit paths:
-       ldmeqfd sp!, {pc}               @ Now <64 bytes to go.
+       ldmeqfd sp!, {r8, pc}           @ Now <64 bytes to go.
(...)
        tst     r2, #16
        stmneia ip!, {r1, r3, r8, lr}
-       ldr     lr, [sp], #4
+       ldmfd   sp!, {r8, lr}

Step 3
======
Make sure r8 is saved and restored when (! CALGN(1)+0) == 0:

save r8:
-       stmfd   sp!, {r4-r7, lr}
+       stmfd   sp!, {r4-r8, lr}

and restore r8 on both exit paths:
        bgt     3b
-       ldmeqfd sp!, {r4-r7, pc}
+       ldmeqfd sp!, {r4-r8, pc}
(...)
        tst     r2, #16
        stmneia ip!, {r4-r7}
-       ldmfd   sp!, {r4-r7, lr}
+       ldmfd   sp!, {r4-r8, lr}

Step 4
======
Rewrite register list "r4-r7, r8" as "r4-r8".

Signed-off-by: default avatarIvan Djelic <ivan.djelic@parrot.com>
Reviewed-by: default avatarNicolas Pitre <nico@linaro.org>
Signed-off-by: default avatarDirk Behme <dirk.behme@gmail.com>
Signed-off-by: default avatarRussell King <rmk+kernel@arm.linux.org.uk>
      455bd4c4
    • Peter Jones's avatar
      x86, doc: Be explicit about what the x86 struct boot_params requires · 3c4aff6b
      Peter Jones authored 
      

If the sentinel triggers, we do not want the boot loader authors to
just poke it and make the error go away, we want them to actually fix
the problem.

This should help avoid making the incorrect change in non-compliant
bootloaders.

[ hpa: dropped the Documentation/x86/boot.txt hunk pending
  clarifications ]

Signed-off-by: default avatarPeter Jones <pjones@redhat.com>
Link: http://lkml.kernel.org/r/1362592823-28967-1-git-send-email-pjones@redhat.com


Signed-off-by: default avatarH. Peter Anvin <hpa@zytor.com>
      3c4aff6b