linux/arch
David S. Miller 2077cef4d5 sparc64: Fix several bugs in memmove().
Firstly, handle zero length calls properly.  Believe it or not there
are a few of these happening during early boot.

Next, we can't just drop to a memcpy() call in the forward copy case
where dst <= src.  The reason is that the cache initializing stores
used in the Niagara memcpy() implementations can end up clearing out
cache lines before we've sourced their original contents completely.

For example, considering NG4memcpy, the main unrolled loop begins like
this:

     load   src + 0x00
     load   src + 0x08
     load   src + 0x10
     load   src + 0x18
     load   src + 0x20
     store  dst + 0x00

Assume dst is 64 byte aligned and let's say that dst is src - 8 for
this memcpy() call.  That store at the end there is the one to the
first line in the cache line, thus clearing the whole line, which thus
clobbers "src + 0x28" before it even gets loaded.

To avoid this, just fall through to a simple copy only mildly
optimized for the case where src and dst are 8 byte aligned and the
length is a multiple of 8 as well.  We could get fancy and call
GENmemcpy() but this is good enough for how this thing is actually
used.

Reported-by: David Ahern <david.ahern@oracle.com>
Reported-by: Bob Picco <bpicco@meloft.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-03-23 09:22:10 -07:00
..
alpha asm-generic: uaccess.h cleanup 2015-02-18 10:02:24 -08:00
arc ARC: Fix thread_saved_pc() 2015-02-27 10:59:34 +05:30
arm Merge git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6 2015-03-18 11:10:41 -07:00
arm64 Merge git://git.kernel.org/pub/scm/virt/kvm/kvm 2015-03-17 10:31:36 -07:00
avr32 asm-generic: uaccess.h cleanup 2015-02-18 10:02:24 -08:00
blackfin Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input 2015-02-21 12:59:04 -08:00
c6x arch/c6x/include/asm/pgtable.h: define dummy pgprot_writecombine for !MMU 2015-03-12 18:46:08 -07:00
cris
frv mm: add missing __PAGETABLE_{PUD,PMD}_FOLDED defines 2015-02-28 09:57:51 -08:00
hexagon
ia64 asm-generic: uaccess.h cleanup 2015-02-18 10:02:24 -08:00
m32r mm: add missing __PAGETABLE_{PUD,PMD}_FOLDED defines 2015-02-28 09:57:51 -08:00
m68k mm: add missing __PAGETABLE_{PUD,PMD}_FOLDED defines 2015-02-28 09:57:51 -08:00
metag metag: Fix KSTK_EIP() and KSTK_ESP() macros 2015-02-24 12:54:21 +00:00
microblaze microblaze: Fix syscall error recovery for invalid syscall IDs 2015-03-04 15:12:27 +01:00
mips KVM: MIPS: Enable after disabling interrupt 2015-03-02 19:18:12 -03:00
mn10300 mm: add missing __PAGETABLE_{PUD,PMD}_FOLDED defines 2015-02-28 09:57:51 -08:00
nios2 nios2: mm: do not invoke OOM killer on kernel fault OOM 2015-03-16 15:35:25 +08:00
openrisc asm-generic: uaccess.h cleanup 2015-02-18 10:02:24 -08:00
parisc mm: add missing __PAGETABLE_{PUD,PMD}_FOLDED defines 2015-02-28 09:57:51 -08:00
powerpc powerpc/iommu: Remove IOMMU device references via bus notifier 2015-03-04 13:19:33 +11:00
s390 kvm: move advertising of KVM_CAP_IRQFD to common code 2015-03-10 21:18:59 -03:00
score
sh asm-generic: uaccess.h cleanup 2015-02-18 10:02:24 -08:00
sparc sparc64: Fix several bugs in memmove(). 2015-03-23 09:22:10 -07:00
tile
um
unicore32
x86 Merge git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6 2015-03-18 11:10:41 -07:00
xtensa asm-generic: uaccess.h cleanup 2015-02-18 10:02:24 -08:00
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