linux-stable.git/arch/arc, branch v4.7.2

ARC: dma: fix address translation in arc_dma_free

2016-08-20T16:10:54+00:00

commit b4dff2874006e54b60ce4f4dbcfec9ab81c6aff4 upstream.

page should be calculated using physical address.
If platform uses non-trivial dma-to-phys memory translation,
dma_handle should be converted to physicval address before
calculation of page.

Failing to do so results in struct page * pointing to
wrong or non-existent memory.

Fixes: f2e3d55397ff ("ARC: dma: reintroduce platform specific dma<->phys")
Signed-off-by: Vladimir Kondratiev 
Signed-off-by: Vineet Gupta 
Signed-off-by: Greg Kroah-Hartman

ARC: mm: don't loose PTE_SPECIAL in pte_modify()

2016-08-20T16:10:54+00:00

commit 3925a16ae980c79d1a8fd182d7f9487da1edd4dc upstream.

LTP madvise05 was generating mm splat

| [ARCLinux]# /sd/ltp/testcases/bin/madvise05
| BUG: Bad page map in process madvise05  pte:80e08211 pmd:9f7d4000
| page:9fdcfc90 count:1 mapcount:-1 mapping:  (null) index:0x0 flags: 0x404(referenced|reserved)
| page dumped because: bad pte
| addr:200b8000 vm_flags:00000070 anon_vma:  (null) mapping:  (null) index:1005c
| file:  (null) fault:  (null) mmap:  (null) readpage:  (null)
| CPU: 2 PID: 6707 Comm: madvise05

And for newer kernels, the system was rendered unusable afterwards.

The problem was mprotect->pte_modify() clearing PTE_SPECIAL (which is
set to identify the special zero page wired to the pte).
When pte was finally unmapped, special casing for zero page was not
done, and instead it was treated as a "normal" page, tripping on the
map counts etc.

This fixes ARC STAR 9001053308

Signed-off-by: Vineet Gupta 
Signed-off-by: Greg Kroah-Hartman

Merge tag 'arc-4.7-rc6-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/vgupta/arc

2016-06-30T16:53:43+00:00

Pull ARC fix from Vineet Gupta:
 "Reinstate dwarf unwinder/loadable-modules with new gnu tools"

* tag 'arc-4.7-rc6-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/vgupta/arc:
  arc: unwind: warn only once if DW2_UNWIND is disabled
  ARC: unwind: ensure that .debug_frame is generated (vs. .eh_frame)

arc: unwind: warn only once if DW2_UNWIND is disabled

2016-06-28T05:41:44+00:00

If CONFIG_ARC_DW2_UNWIND is disabled every time arc_unwind_core()
gets called following message gets printed in debug console:
----------------->8---------------
CONFIG_ARC_DW2_UNWIND needs to be enabled
----------------->8---------------

That message makes sense if user indeed wants to see a backtrace or
get nice function call-graphs in perf but what if user disabled
unwinder for the purpose? Why pollute his debug console?

So instead we'll warn user about possibly missing feature once and
let him decide if that was what he or she really wanted.

Signed-off-by: Alexey Brodkin 
Cc: stable@vger.kernel.org
Signed-off-by: Vineet Gupta

ARC: unwind: ensure that .debug_frame is generated (vs. .eh_frame)

2016-06-28T04:12:28+00:00

With recent binutils update to support dwarf CFI pseudo-ops in gas, we
now get .eh_frame vs. .debug_frame. Although the call frame info is
exactly the same in both, the CIE differs, which the current kernel
unwinder can't cope with.

This broke both the kernel unwinder as well as loadable modules (latter
because of a new unhandled relo R_ARC_32_PCREL from .rela.eh_frame in
the module loader)

The ideal solution would be to switch unwinder to .eh_frame.
For now however we can make do by just ensureing .debug_frame is
generated by removing -fasynchronous-unwind-tables

 .eh_frame    generated with -gdwarf-2 -fasynchronous-unwind-tables
 .debug_frame generated with -gdwarf-2

Fixes STAR 9001058196

Cc: stable@vger.kernel.org
Signed-off-by: Vineet Gupta

arc: get rid of superfluous __GFP_REPEAT

2016-06-25T00:23:52+00:00

__GFP_REPEAT has a rather weak semantic but since it has been introduced
around 2.6.12 it has been ignored for low order allocations.

pte_alloc_one_kernel uses __get_order_pte but this is obviously always
zero because BITS_FOR_PTE is not larger than 9 yet the page size is
always larger than 4K.  This means that this flag has never been
actually useful here because it has always been used only for
PAGE_ALLOC_COSTLY requests.

Link: http://lkml.kernel.org/r/1464599699-30131-7-git-send-email-mhocko@kernel.org
Signed-off-by: Michal Hocko 
Acked-by: Vineet Gupta 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

Revert "ARCv2: spinlock/rwlock/atomics: Delayed retry of failed SCOND with exponential backoff"

2016-06-02T05:29:23+00:00

This reverts commit e78fdfef84be13a5c2b8276e12203cdf24778596.

The issue was fixed in hardware in HS2.1C release and there are no known
external users of affected RTL so revert the whole delayed retry series !

Signed-off-by: Vineet Gupta

Revert "ARCv2: spinlock/rwlock: Reset retry delay when starting a new spin-wait cycle"

2016-06-02T05:29:23+00:00

This reverts commit b89aa12c177477e34caa722818536fb5d0bffd76.

The issue was fixed in hardware in HS2.1C release and there are no known
external users of affected RTL so revert the whole delayed retry series !

Signed-off-by: Vineet Gupta

Revert "ARCv2: spinlock/rwlock/atomics: reduce 1 instruction in exponential backoff"

2016-06-02T05:29:22+00:00

This reverts commit 10971638701dedadb58c88ce4d31c9375b224ed6.

The issue was fixed in hardware in HS2.1C release and there are no known
external users of affected RTL - so revert thw whole delayed retry
series !

Signed-off-by: Vineet Gupta

ARC: don't enable DISCONTIGMEM unconditionally

2016-05-31T06:16:47+00:00

Signed-off-by: Vineet Gupta