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  1. 04 3月, 2014 2 次提交
    • D
      mm: close PageTail race · 668f9abb
      由 David Rientjes 提交于 
      Commit bf6bddf1 ("mm: introduce compaction and migration for
ballooned pages") introduces page_count(page) into memory compaction
which dereferences page->first_page if PageTail(page).

This results in a very rare NULL pointer dereference on the
aforementioned page_count(page).  Indeed, anything that does
compound_head(), including page_count() is susceptible to racing with
prep_compound_page() and seeing a NULL or dangling page->first_page
pointer.

This patch uses Andrea's implementation of compound_trans_head() that
deals with such a race and makes it the default compound_head()
implementation.  This includes a read memory barrier that ensures that
if PageTail(head) is true that we return a head page that is neither
NULL nor dangling.  The patch then adds a store memory barrier to
prep_compound_page() to ensure page->first_page is set.

This is the safest way to ensure we see the head page that we are
expecting, PageTail(page) is already in the unlikely() path and the
memory barriers are unfortunately required.

Hugetlbfs is the exception, we don't enforce a store memory barrier
during init since no race is possible.
Signed-off-by: NDavid Rientjes <rientjes@google.com>
Cc: Holger Kiehl <Holger.Kiehl@dwd.de>
Cc: Christoph Lameter <cl@linux.com>
Cc: Rafael Aquini <aquini@redhat.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      668f9abb
    • B
      MAINTAINERS: EDAC: add Mauro and Borislav as interim patch collectors · aa15aa0e
      由 Borislav Petkov 提交于 
      We're more or less collecting EDAC patches already anyway so let's hold it
down so that get_maintainer sees it too.
Signed-off-by: NBorislav Petkov <bp@suse.de>
Acked-by: NMauro Carvalho Chehab <m.chehab@samsung.com>
Cc: Doug Thompson <dougthompson@xmission.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      aa15aa0e
  3. 03 3月, 2014 8 次提交
  5. 02 3月, 2014 8 次提交
  7. 01 3月, 2014 10 次提交
  9. 28 2月, 2014 12 次提交
    • S
      arm64: mm: Add double logical invert to pte accessors · 84fe6826
      由 Steve Capper 提交于 
      Page table entries on ARM64 are 64 bits, and some pte functions such as
pte_dirty return a bitwise-and of a flag with the pte value. If the
flag to be tested resides in the upper 32 bits of the pte, then we run
into the danger of the result being dropped if downcast.

For example:
	gather_stats(page, md, pte_dirty(*pte), 1);
where pte_dirty(*pte) is downcast to an int.

This patch adds a double logical invert to all the pte_ accessors to
ensure predictable downcasting.
Signed-off-by: NSteve Capper <steve.capper@linaro.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: NCatalin Marinas <catalin.marinas@arm.com>
      84fe6826
    • H
      dm cache: fix truncation bug when mapping I/O to >2TB fast device · e0d849fa
      由 Heinz Mauelshagen 提交于 
      When remapping a block to the cache's fast device that is larger than
2TB we must not truncate the destination sector to 32bits.  The 32bit
temporary result of from_cblock() was being overflowed in
remap_to_cache() due to the logical left shift.

Use an intermediate 64bit type to store the 32bit from_cblock() result
to fix the overflow.
Signed-off-by: NHeinz Mauelshagen <heinzm@redhat.com>
Signed-off-by: NMike Snitzer <snitzer@redhat.com>
Cc: stable@vger.kernel.org
      e0d849fa
    • J
      perf tools: Fix strict alias issue for find_first_bit · b39c2a57
      由 Jiri Olsa 提交于 
      When compiling perf tool code with gcc 4.4.7 I'm getting
following error:

    CC       util/session.o
  cc1: warnings being treated as errors
  util/session.c: In function ‘perf_session_deliver_event’:
  tools/perf/util/include/linux/bitops.h:109: error: dereferencing pointer ‘p’ does break strict-aliasing rules
  tools/perf/util/include/linux/bitops.h:101: error: dereferencing pointer ‘p’ does break strict-aliasing rules
  util/session.c:697: note: initialized from here
  tools/perf/util/include/linux/bitops.h:101: note: initialized from here
  make[1]: *** [util/session.o] Error 1
  make: *** [util/session.o] Error 2

The aliased types here are u64 and unsigned long pointers, which is safe
for the find_first_bit processing.

This error shows up for me only for gcc 4.4 on 32bit x86, even for
-Wstrict-aliasing=3, while newer gcc are quiet and scream here for
-Wstrict-aliasing={2,1}. Looks like newer gcc changed the rules for
strict alias warnings.

The gcc documentation offers workaround for valid aliasing by using
__may_alias__ attribute:

  http://gcc.gnu.org/onlinedocs/gcc-4.4.0/gcc/Type-Attributes.html

Using this workaround for the find_first_bit function.
Signed-off-by: NJiri Olsa <jolsa@redhat.com>
Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1393434867-20271-1-git-send-email-jolsa@redhat.comSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>
      b39c2a57
    • B
      powerpc/powernv: Fix indirect XSCOM unmangling · e0cf9576
      由 Benjamin Herrenschmidt 提交于 
      We need to unmangle the full address, not just the register
number, and we also need to support the real indirect bit
being set for in-kernel uses.
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>
CC: <stable@vger.kernel.org> [v3.13]
      e0cf9576
    • B
      powerpc/powernv: Fix opal_xscom_{read,write} prototype · 2f3f38e4
      由 Benjamin Herrenschmidt 提交于 
      The OPAL firmware functions opal_xscom_read and opal_xscom_write
take a 64-bit argument for the XSCOM (PCB) address in order to
support the indirect mode on P8.
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>
CC: <stable@vger.kernel.org> [v3.13]
      2f3f38e4
    • G
      powerpc/powernv: Refactor PHB diag-data dump · af87d2fe
      由 Gavin Shan 提交于 
      As Ben suggested, the patch prints PHB diag-data with multiple
fields in one line and omits the line if the fields of that
line are all zero.

With the patch applied, the PHB3 diag-data dump looks like:

PHB3 PHB#3 Diag-data (Version: 1)

  brdgCtl:     00000002
  RootSts:     0000000f 00400000 b0830008 00100147 00002000
  nFir:        0000000000000000 0030006e00000000 0000000000000000
  PhbSts:      0000001c00000000 0000000000000000
  Lem:         0000000000100000 42498e327f502eae 0000000000000000
  InAErr:      8000000000000000 8000000000000000 0402030000000000 0000000000000000
  PE[  8] A/B: 8480002b00000000 8000000000000000

[ The current diag data is so big that it overflows the printk
  buffer pretty quickly in cases when we get a handful of errors
  at once which can happen. --BenH
]
Signed-off-by: NGavin Shan <shangw@linux.vnet.ibm.com>
CC: <stable@vger.kernel.org>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>
      af87d2fe
    • G
      powerpc/powernv: Dump PHB diag-data immediately · 94716604
      由 Gavin Shan 提交于 
      The PHB diag-data is important to help locating the root cause for
EEH errors such as frozen PE or fenced PHB. However, the EEH core
enables IO path by clearing part of HW registers before collecting
this data causing it to be corrupted.

This patch fixes this by dumping the PHB diag-data immediately when
frozen/fenced state on PE or PHB is detected for the first time in
eeh_ops::get_state() or next_error() backend.
Signed-off-by: NGavin Shan <shangw@linux.vnet.ibm.com>
CC: <stable@vger.kernel.org>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>
      94716604
    • P
      powerpc: Increase stack redzone for 64-bit userspace to 512 bytes · 573ebfa6
      由 Paul Mackerras 提交于 
      The new ELFv2 little-endian ABI increases the stack redzone -- the
area below the stack pointer that can be used for storing data --
from 288 bytes to 512 bytes.  This means that we need to allow more
space on the user stack when delivering a signal to a 64-bit process.

To make the code a bit clearer, we define new USER_REDZONE_SIZE and
KERNEL_REDZONE_SIZE symbols in ptrace.h.  For now, we leave the
kernel redzone size at 288 bytes, since increasing it to 512 bytes
would increase the size of interrupt stack frames correspondingly.

Gcc currently only makes use of 288 bytes of redzone even when
compiling for the new little-endian ABI, and the kernel cannot
currently be compiled with the new ABI anyway.

In the future, hopefully gcc will provide an option to control the
amount of redzone used, and then we could reduce it even more.

This also changes the code in arch_compat_alloc_user_space() to
preserve the expanded redzone.  It is not clear why this function would
ever be used on a 64-bit process, though.
Signed-off-by: NPaul Mackerras <paulus@samba.org>
CC: <stable@vger.kernel.org> [v3.13]
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>
      573ebfa6
    • L
      powerpc/ftrace: bugfix for test_24bit_addr · a95fc585
      由 Liu Ping Fan 提交于 
      The branch target should be the func addr, not the addr of func_descr_t.
So using ppc_function_entry() to generate the right target addr.
Signed-off-by: NLiu Ping Fan <pingfank@linux.vnet.ibm.com>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>
      a95fc585
    • L
      powerpc/crashdump : Fix page frame number check in copy_oldmem_page · f5295bd8
      由 Laurent Dufour 提交于 
      In copy_oldmem_page, the current check using max_pfn and min_low_pfn to
decide if the page is backed or not, is not valid when the memory layout is
not continuous.

This happens when running as a QEMU/KVM guest, where RTAS is mapped higher
in the memory. In that case max_pfn points to the end of RTAS, and a hole
between the end of the kdump kernel and RTAS is not backed by PTEs. As a
consequence, the kdump kernel is crashing in copy_oldmem_page when accessing
in a direct way the pages in that hole.

This fix relies on the memblock's service memblock_is_region_memory to
check if the read page is part or not of the directly accessible memory.
Signed-off-by: NLaurent Dufour <ldufour@linux.vnet.ibm.com>
Tested-by: NMahesh Salgaonkar <mahesh@linux.vnet.ibm.com>
CC: <stable@vger.kernel.org>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>
      f5295bd8
    • T
      powerpc/le: Ensure that the 'stop-self' RTAS token is handled correctly · 41dd03a9
      由 Tony Breeds 提交于 
      Currently we're storing a host endian RTAS token in
rtas_stop_self_args.token.  We then pass that directly to rtas.  This is
fine on big endian however on little endian the token is not what we
expect.

This will typically result in hitting:
	panic("Alas, I survived.\n");

To fix this we always use the stop-self token in host order and always
convert it to be32 before passing this to rtas.
Signed-off-by: NTony Breeds <tony@bakeyournoodle.com>
Cc: stable@vger.kernel.org
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>
      41dd03a9
    • R
      Merge branches 'pm-cpufreq', 'pm-hibernate' and 'acpi-processor' · 6c09ea49
      由 Rafael J. Wysocki 提交于 
      * pm-cpufreq:
  intel_pstate: Change busy calculation to use fixed point math.

* pm-hibernate:
  PM / hibernate: Fix restore hang in freeze_processes()

* acpi-processor:
  ACPI / processor: Rework processor throttling with work_on_cpu()
      6c09ea49