1. 14 Jun, 2018 1 commit
  2. 06 Apr, 2018 1 commit
    • Huang Ying's avatar
      mm: fix races between swapoff and flush dcache · cb9f753a
      Huang Ying authored
      Thanks to commit 4b3ef9da ("mm/swap: split swap cache into 64MB
      trunks"), after swapoff the address_space associated with the swap
      device will be freed.  So page_mapping() users which may touch the
      address_space need some kind of mechanism to prevent the address_space
      from being freed during accessing.
      
      The dcache flushing functions (flush_dcache_page(), etc) in architecture
      specific code may access the address_space of swap device for anonymous
      pages in swap cache via page_mapping() function.  But in some cases
      there are no mechanisms to prevent the swap device from being swapoff,
      for example,
      
        CPU1					CPU2
        __get_user_pages()			swapoff()
          flush_dcache_page()
            mapping = page_mapping()
              ...				  exit_swap_address_space()
              ...				    kvfree(spaces)
              mapping_mapped(mapping)
      
      The address space may be accessed after being freed.
      
      But from cachetlb.txt and Russell King, flush_dcache_page() only care
      about file cache pages, for anonymous pages, flush_anon_page() should be
      used.  The implementation of flush_dcache_page() in all architectures
      follows this too.  They will check whether page_mapping() is NULL and
      whether mapping_mapped() is true to determine whether to flush the
      dcache immediately.  And they will use interval tree (mapping->i_mmap)
      to find all user space mappings.  While mapping_mapped() and
      mapping->i_mmap isn't used by anonymous pages in swap cache at all.
      
      So, to fix the race between swapoff and flush dcache, __page_mapping()
      is add to return the address_space for file cache pages and NULL
      otherwise.  All page_mapping() invoking in flush dcache functions are
      replaced with page_mapping_file().
      
      [akpm@linux-foundation.org: simplify page_mapping_file(), per Mike]
      Link: http://lkml.kernel.org/r/20180305083634.15174-1-ying.huang@intel.com
      
      Signed-off-by: default avatar"Huang, Ying" <ying.huang@intel.com>
      Reviewed-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Cc: Minchan Kim <minchan@kernel.org>
      Cc: Michal Hocko <mhocko@suse.com>
      Cc: Johannes Weiner <hannes@cmpxchg.org>
      Cc: Mel Gorman <mgorman@techsingularity.net>
      Cc: Dave Hansen <dave.hansen@intel.com>
      Cc: Chen Liqin <liqin.linux@gmail.com>
      Cc: Russell King <linux@armlinux.org.uk>
      Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
      Cc: "James E.J. Bottomley" <jejb@parisc-linux.org>
      Cc: Guan Xuetao <gxt@mprc.pku.edu.cn>
      Cc: "David S. Miller" <davem@davemloft.net>
      Cc: Chris Zankel <chris@zankel.net>
      Cc: Vineet Gupta <vgupta@synopsys.com>
      Cc: Ley Foon Tan <lftan@altera.com>
      Cc: Ralf Baechle <ralf@linux-mips.org>
      Cc: Andi Kleen <ak@linux.intel.com>
      Cc: Mike Rapoport <rppt@linux.vnet.ibm.com>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      cb9f753a
  3. 18 Mar, 2018 1 commit
    • Khalid Aziz's avatar
      sparc64: Add support for ADI (Application Data Integrity) · 74a04967
      Khalid Aziz authored
      
      
      ADI is a new feature supported on SPARC M7 and newer processors to allow
      hardware to catch rogue accesses to memory. ADI is supported for data
      fetches only and not instruction fetches. An app can enable ADI on its
      data pages, set version tags on them and use versioned addresses to
      access the data pages. Upper bits of the address contain the version
      tag. On M7 processors, upper four bits (bits 63-60) contain the version
      tag. If a rogue app attempts to access ADI enabled data pages, its
      access is blocked and processor generates an exception. Please see
      Documentation/sparc/adi.txt for further details.
      
      This patch extends mprotect to enable ADI (TSTATE.mcde), enable/disable
      MCD (Memory Corruption Detection) on selected memory ranges, enable
      TTE.mcd in PTEs, return ADI parameters to userspace and save/restore ADI
      version tags on page swap out/in or migration. ADI is not enabled by
      default for any task. A task must explicitly enable ADI on a memory
      range and set version tag for ADI to be effective for the task.
      Signed-off-by: default avatarKhalid Aziz <khalid.aziz@oracle.com>
      Cc: Khalid Aziz <khalid@gonehiking.org>
      Reviewed-by: default avatarAnthony Yznaga <anthony.yznaga@oracle.com>
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      74a04967
  4. 08 Jan, 2018 2 commits
  5. 16 Nov, 2017 4 commits
  6. 02 Nov, 2017 1 commit
    • Greg Kroah-Hartman's avatar
      License cleanup: add SPDX GPL-2.0 license identifier to files with no license · b2441318
      Greg Kroah-Hartman authored
      Many source files in the tree are missing licensing information, which
      makes it harder for compliance tools to determine the correct license.
      
      By default all files without license information are under the default
      license of the kernel, which is GPL version 2.
      
      Update the files which contain no license information with the 'GPL-2.0'
      SPDX license identifier.  The SPDX identifier is a legally binding
      shorthand, which can be used instead of the full boiler plate text.
      
      This patch is based on work done by Thomas Gleixner and Kate Stewart and
      Philippe Ombredanne.
      
      How this work was done:
      
      Patches were generated and checked against linux-4.14-rc6 for a subset of
      the use cases:
       - file had no licensing information it it.
       - file was a */uapi/* one with no licensing information in it,
       - file was a */uapi/* one with existing licensing information,
      
      Further patches will be generated in subsequent months to fix up cases
      where non-standard...
      b2441318
  7. 16 Aug, 2017 1 commit
  8. 10 Aug, 2017 2 commits
  9. 04 Aug, 2017 2 commits
  10. 20 Jul, 2017 1 commit
    • Nitin Gupta's avatar
      sparc64: Register hugepages during arch init · 8399e4b8
      Nitin Gupta authored
      
      
      Add hstate for each supported hugepage size using
      arch initcall. This change fixes some hugepage
      parameter parsing inconsistencies:
      
      case 1: no hugepage parameters
      
       Without hugepage parameters, only a hugepages-8192kB entry is visible
       in sysfs.  It's different from x86_64 where both 2M and 1G hugepage
       sizes are available.
      
      case 2: default_hugepagesz=[64K|256M|2G]
      
       When specifying only a default_hugepagesz parameter, the default
       hugepage size isn't really changed and it stays at 8M. This is again
       different from x86_64.
      
      Orabug: 25869946
      Reviewed-by: default avatarBob Picco <bob.picco@oracle.com>
      Signed-off-by: default avatarNitin Gupta <nitin.m.gupta@oracle.com>
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      8399e4b8
  11. 06 Jun, 2017 5 commits
    • Pavel Tatashin's avatar
      sparc64: new context wrap · a0582f26
      Pavel Tatashin authored
      
      
      The current wrap implementation has a race issue: it is called outside of
      the ctx_alloc_lock, and also does not wait for all CPUs to complete the
      wrap.  This means that a thread can get a new context with a new version
      and another thread might still be running with the same context. The
      problem is especially severe on CPUs with shared TLBs, like sun4v. I used
      the following test to very quickly reproduce the problem:
      - start over 8K processes (must be more than context IDs)
      - write and read values at a  memory location in every process.
      
      Very quickly memory corruptions start happening, and what we read back
      does not equal what we wrote.
      
      Several approaches were explored before settling on this one:
      
      Approach 1:
      Move smp_new_mmu_context_version() inside ctx_alloc_lock, and wait for
      every process to complete the wrap. (Note: every CPU must WAIT before
      leaving smp_new_mmu_context_version_client() until every one arrives).
      
      This approach ends up with deadlocks, as some threads own locks which other
      threads are waiting for, and they never receive softint until these threads
      exit smp_new_mmu_context_version_client(). Since we do not allow the exit,
      deadlock happens.
      
      Approach 2:
      Handle wrap right during mondo interrupt. Use etrap/rtrap to enter into
      into C code, and issue new versions to every CPU.
      This approach adds some overhead to runtime: in switch_mm() we must add
      some checks to make sure that versions have not changed due to wrap while
      we were loading the new secondary context. (could be protected by PSTATE_IE
      but that degrades performance as on M7 and older CPUs as it takes 50 cycles
      for each access). Also, we still need a global per-cpu array of MMs to know
      where we need to load new contexts, otherwise we can change context to a
      thread that is going way (if we received mondo between switch_mm() and
      switch_to() time). Finally, there are some issues with window registers in
      rtrap() when context IDs are changed during CPU mondo time.
      
      The approach in this patch is the simplest and has almost no impact on
      runtime.  We use the array with mm's where last secondary contexts were
      loaded onto CPUs and bump their versions to the new generation without
      changing context IDs. If a new process comes in to get a context ID, it
      will go through get_new_mmu_context() because of version mismatch. But the
      running processes do not need to be interrupted. And wrap is quicker as we
      do not need to xcall and wait for everyone to receive and complete wrap.
      Signed-off-by: default avatarPavel Tatashin <pasha.tatashin@oracle.com>
      Reviewed-by: default avatarBob Picco <bob.picco@oracle.com>
      Reviewed-by: default avatarSteven Sistare <steven.sistare@oracle.com>
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      a0582f26
    • Pavel Tatashin's avatar
      sparc64: add per-cpu mm of secondary contexts · 7a5b4bbf
      Pavel Tatashin authored
      
      
      The new wrap is going to use information from this array to figure out
      mm's that currently have valid secondary contexts setup.
      Signed-off-by: default avatarPavel Tatashin <pasha.tatashin@oracle.com>
      Reviewed-by: default avatarBob Picco <bob.picco@oracle.com>
      Reviewed-by: default avatarSteven Sistare <steven.sistare@oracle.com>
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      7a5b4bbf
    • Pavel Tatashin's avatar
      sparc64: redefine first version · c4415235
      Pavel Tatashin authored
      
      
      CTX_FIRST_VERSION defines the first context version, but also it defines
      first context. This patch redefines it to only include the first context
      version.
      Signed-off-by: default avatarPavel Tatashin <pasha.tatashin@oracle.com>
      Reviewed-by: default avatarBob Picco <bob.picco@oracle.com>
      Reviewed-by: default avatarSteven Sistare <steven.sistare@oracle.com>
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      c4415235
    • Pavel Tatashin's avatar
      sparc64: reset mm cpumask after wrap · 58897485
      Pavel Tatashin authored
      
      
      After a wrap (getting a new context version) a process must get a new
      context id, which means that we would need to flush the context id from
      the TLB before running for the first time with this ID on every CPU. But,
      we use mm_cpumask to determine if this process has been running on this CPU
      before, and this mask is not reset after a wrap. So, there are two possible
      fixes for this issue:
      
      1. Clear mm cpumask whenever mm gets a new context id
      2. Unconditionally flush context every time process is running on a CPU
      
      This patch implements the first solution
      Signed-off-by: default avatarPavel Tatashin <pasha.tatashin@oracle.com>
      Reviewed-by: default avatarBob Picco <bob.picco@oracle.com>
      Reviewed-by: default avatarSteven Sistare <steven.sistare@oracle.com>
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      58897485
    • Liam R. Howlett's avatar
      sparc/mm/hugepages: Fix setup_hugepagesz for invalid values. · f322980b
      Liam R. Howlett authored
      
      
      hugetlb_bad_size needs to be called on invalid values.  Also change the
      pr_warn to a pr_err to better align with other platforms.
      Signed-off-by: default avatarLiam R. Howlett <Liam.Howlett@Oracle.com>
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      f322980b
  12. 28 Mar, 2017 2 commits
  13. 23 Feb, 2017 4 commits
  14. 24 Dec, 2016 1 commit
  15. 14 Nov, 2016 1 commit
  16. 11 Nov, 2016 1 commit
    • Thomas Tai's avatar
      sparc64: Fix find_node warning if numa node cannot be found · 74a5ed5c
      Thomas Tai authored
      
      
      When booting up LDOM, find_node() warns that a physical address
      doesn't match a NUMA node.
      
      WARNING: CPU: 0 PID: 0 at arch/sparc/mm/init_64.c:835
      find_node+0xf4/0x120 find_node: A physical address doesn't
      match a NUMA node rule. Some physical memory will be
      owned by node 0.Modules linked in:
      
      CPU: 0 PID: 0 Comm: swapper Not tainted 4.9.0-rc3 #4
      Call Trace:
       [0000000000468ba0] __warn+0xc0/0xe0
       [0000000000468c74] warn_slowpath_fmt+0x34/0x60
       [00000000004592f4] find_node+0xf4/0x120
       [0000000000dd0774] add_node_ranges+0x38/0xe4
       [0000000000dd0b1c] numa_parse_mdesc+0x268/0x2e4
       [0000000000dd0e9c] bootmem_init+0xb8/0x160
       [0000000000dd174c] paging_init+0x808/0x8fc
       [0000000000dcb0d0] setup_arch+0x2c8/0x2f0
       [0000000000dc68a0] start_kernel+0x48/0x424
       [0000000000dcb374] start_early_boot+0x27c/0x28c
       [0000000000a32c08] tlb_fixup_done+0x4c/0x64
       [0000000000027f08] 0x27f08
      
      It is because linux use an internal structure node_masks[] to
      keep the best memory latency node only. However, LDOM mdesc can
      contain single latency-group with multiple memory latency nodes.
      
      If the address doesn't match the best latency node within
      node_masks[], it should check for an alternative via mdesc.
      The warning message should only be printed if the address
      doesn't match any node_masks[] nor within mdesc. To minimize
      the impact of searching mdesc every time, the last matched
      mask and index is stored in a variable.
      Signed-off-by: default avatarThomas Tai <thomas.tai@oracle.com>
      Reviewed-by: default avatarChris Hyser <chris.hyser@oracle.com>
      Reviewed-by: default avatarLiam Merwick <liam.merwick@oracle.com>
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      74a5ed5c
  17. 06 Oct, 2016 1 commit
  18. 28 Sep, 2016 2 commits
    • Atish Patra's avatar
      sparc64: Fix irq stack bootmem allocation. · ebb99a4c
      Atish Patra authored
      
      
      Currently, irq stack bootmem is allocated for all possible cpus
      before nr_cpus value changes the list of possible cpus. As a result,
      there is unnecessary wastage of bootmemory.
      
      Move the irq stack bootmem allocation so that it happens after
      possible cpu list is modified based on nr_cpus value.
      Signed-off-by: default avatarAtish Patra <atish.patra@oracle.com>
      Reviewed-by: default avatarBob Picco <bob.picco@oracle.com>
      Reviewed-by: default avatarVijay Kumar <vijay.ac.kumar@oracle.com>
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      ebb99a4c
    • Paul Gortmaker's avatar
      sparc64: fix section mismatch in find_numa_latencies_for_group · bdf2f59e
      Paul Gortmaker authored
      
      
      To fix:
      
        WARNING: vmlinux.o(.text.unlikely+0x580): Section mismatch in
        reference from the function find_numa_latencies_for_group() to the
        function .init.text:find_mlgroup()
      
        The function find_numa_latencies_for_group() references the
        function __init find_mlgroup().  This is often because
        find_numa_latencies_for_group lacks a __init annotation or the
        annotation of find_mlgroup is wrong.
      
      It turns out find_numa_latencies_for_group is only called from:
          static int __init numa_parse_mdesc(void)
      and hence we can tag find_numa_latencies_for_group with __init.
      
      In doing so we see that find_best_numa_node_for_mlgroup is only
      called from within __init and hence can also be marked with __init.
      
      Cc: "David S. Miller" <davem@davemloft.net>
      Cc: Nitin Gupta <nitin.m.gupta@oracle.com>
      Cc: Chris Hyser <chris.hyser@oracle.com>
      Cc: Santosh Shilimkar <santosh.shilimkar@oracle.com>
      Cc: sparclinux@vger.kernel.org
      Signed-off-by: default avatarPaul Gortmaker <paul.gortmaker@windriver.com>
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      bdf2f59e
  19. 29 Jul, 2016 2 commits
    • Nitin Gupta's avatar
      sparc64: Trim page tables for 8M hugepages · 7bc3777c
      Nitin Gupta authored
      
      
      For PMD aligned (8M) hugepages, we currently allocate
      all four page table levels which is wasteful. We now
      allocate till PMD level only which saves memory usage
      from page tables.
      
      Also, when freeing page table for 8M hugepage backed region,
      make sure we don't try to access non-existent PTE level.
      
      Orabug: 22630259
      Signed-off-by: default avatarNitin Gupta <nitin.m.gupta@oracle.com>
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      7bc3777c
    • Mike Kravetz's avatar
      sparc64 mm: Fix base TSB sizing when hugetlb pages are used · af1b1a9b
      Mike Kravetz authored
      
      
      do_sparc64_fault() calculates both the base and huge page RSS sizes and
      uses this information in calls to tsb_grow().  The calculation for base
      page TSB size is not correct if the task uses hugetlb pages.  hugetlb
      pages are not accounted for in RSS, therefore the call to get_mm_rss(mm)
      does not include hugetlb pages.  However, the number of pages based on
      huge_pte_count (which does include hugetlb pages) is subtracted from
      this value.  This will result in an artificially small and often negative
      RSS calculation.  The base TSB size is then often set to max_tsb_size
      as the passed RSS is unsigned, so a negative value looks really big.
      
      THP pages are also accounted for in huge_pte_count, and THP pages are
      accounted for in RSS so the calculation in do_sparc64_fault() is correct
      if a task only uses THP pages.
      
      A single huge_pte_count is not sufficient for TSB sizing if both hugetlb
      and THP pages can be used.  Instead of a single counter, use two:  one
      for hugetlb and one for THP.
      Signed-off-by: default avatarMike Kravetz <mike.kravetz@oracle.com>
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      af1b1a9b
  20. 25 Jun, 2016 1 commit
    • Michal Hocko's avatar
      tree wide: get rid of __GFP_REPEAT for order-0 allocations part I · 32d6bd90
      Michal Hocko authored
      This is the third version of the patchset previously sent [1].  I have
      basically only rebased it on top of 4.7-rc1 tree and dropped "dm: get
      rid of superfluous gfp flags" which went through dm tree.  I am sending
      it now because it is tree wide and chances for conflicts are reduced
      considerably when we want to target rc2.  I plan to send the next step
      and rename the flag and move to a better semantic later during this
      release cycle so we will have a new semantic ready for 4.8 merge window
      hopefully.
      
      Motivation:
      
      While working on something unrelated I've checked the current usage of
      __GFP_REPEAT in the tree.  It seems that a majority of the usage is and
      always has been bogus because __GFP_REPEAT has always been about costly
      high order allocations while we are using it for order-0 or very small
      orders very often.  It seems that a big pile of them is just a
      copy&paste when a code has been adopted from one arch to another.
      
      I think it makes some sense to get rid of them because they are just
      making the semantic more unclear.  Please note that GFP_REPEAT is
      documented as
      
      * __GFP_REPEAT: Try hard to allocate the memory, but the allocation attempt
      
      * _might_ fail.  This depends upon the particular VM implementation.
        while !costly requests have basically nofail semantic.  So one could
        reasonably expect that order-0 request with __GFP_REPEAT will not loop
        for ever.  This is not implemented right now though.
      
      I would like to move on with __GFP_REPEAT and define a better semantic
      for it.
      
        $ git grep __GFP_REPEAT origin/master | wc -l
        111
        $ git grep __GFP_REPEAT | wc -l
        36
      
      So we are down to the third after this patch series.  The remaining
      places really seem to be relying on __GFP_REPEAT due to large allocation
      requests.  This still needs some double checking which I will do later
      after all the simple ones are sorted out.
      
      I am touching a lot of arch specific code here and I hope I got it right
      but as a matter of fact I even didn't compile test for some archs as I
      do not have cross compiler for them.  Patches should be quite trivial to
      review for stupid compile mistakes though.  The tricky parts are usually
      hidden by macro definitions and thats where I would appreciate help from
      arch maintainers.
      
      [1] http://lkml.kernel.org/r/1461849846-27209-1-git-send-email-mhocko@kernel.org
      
      This patch (of 19):
      
      __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.  Yet we
      have the full kernel tree with its usage for apparently order-0
      allocations.  This is really confusing because __GFP_REPEAT is
      explicitly documented to allow allocation failures which is a weaker
      semantic than the current order-0 has (basically nofail).
      
      Let's simply drop __GFP_REPEAT from those places.  This would allow to
      identify place which really need allocator to retry harder and formulate
      a more specific semantic for what the flag is supposed to do actually.
      
      Link: http://lkml.kernel.org/r/1464599699-30131-2-git-send-email-mhocko@kernel.org
      
      Signed-off-by: default avatarMichal Hocko <mhocko@suse.com>
      Cc: "David S. Miller" <davem@davemloft.net>
      Cc: "H. Peter Anvin" <hpa@zytor.com>
      Cc: "James E.J. Bottomley" <jejb@parisc-linux.org>
      Cc: "Theodore Ts'o" <tytso@mit.edu>
      Cc: Andy Lutomirski <luto@kernel.org>
      Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
      Cc: Catalin Marinas <catalin.marinas@arm.com>
      Cc: Chen Liqin <liqin.linux@gmail.com>
      Cc: Chris Metcalf <cmetcalf@mellanox.com> [for tile]
      Cc: Guan Xuetao <gxt@mprc.pku.edu.cn>
      Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
      Cc: Helge Deller <deller@gmx.de>
      Cc: Ingo Molnar <mingo@redhat.com>
      Cc: Jan Kara <jack@suse.cz>
      Cc: John Crispin <blogic@openwrt.org>
      Cc: Lennox Wu <lennox.wu@gmail.com>
      Cc: Ley Foon Tan <lftan@altera.com>
      Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
      Cc: Matt Fleming <matt@codeblueprint.co.uk>
      Cc: Ralf Baechle <ralf@linux-mips.org>
      Cc: Rich Felker <dalias@libc.org>
      Cc: Russell King <linux@arm.linux.org.uk>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Cc: Vineet Gupta <vgupta@synopsys.com>
      Cc: Will Deacon <will.deacon@arm.com>
      Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      32d6bd90
  21. 25 May, 2016 1 commit
  22. 21 May, 2016 1 commit
  23. 21 Apr, 2016 1 commit
  24. 30 Jan, 2016 1 commit
    • Toshi Kani's avatar
      arch: Set IORESOURCE_SYSTEM_RAM flag for System RAM · 35d98e93
      Toshi Kani authored
      
      
      Set IORESOURCE_SYSTEM_RAM in flags of resource ranges with
      "System RAM", "Kernel code", "Kernel data", and "Kernel bss".
      
      Note that:
      
       - IORESOURCE_SYSRAM (i.e. modifier bit) is set in flags when
         IORESOURCE_MEM is already set. IORESOURCE_SYSTEM_RAM is defined
         as (IORESOURCE_MEM|IORESOURCE_SYSRAM).
      
       - Some archs do not set 'flags' for children nodes, such as
         "Kernel code".  This patch does not change 'flags' in this
         case.
      Signed-off-by: default avatarToshi Kani <toshi.kani@hpe.com>
      Signed-off-by: default avatarBorislav Petkov <bp@suse.de>
      Cc: Andrew Morton <akpm@linux-foundation.org>
      Cc: Andy Lutomirski <luto@amacapital.net>
      Cc: Borislav Petkov <bp@alien8.de>
      Cc: Brian Gerst <brgerst@gmail.com>
      Cc: Denys Vlasenko <dvlasenk@redhat.com>
      Cc: H. Peter Anvin <hpa@zytor.com>
      Cc: Linus Torvalds <torvalds@linux-foundation.org>
      Cc: Luis R. Rodriguez <mcgrof@suse.com>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Cc: Toshi Kani <toshi.kani@hp.com>
      Cc: linux-arch@vger.kernel.org
      Cc: linux-arm-kernel@lists.infradead.org
      Cc: linux-mips@linux-mips.org
      Cc: linux-mm <linux-mm@kvack.org>
      Cc: linux-parisc@vger.kernel.org
      Cc: linux-s390@vger.kernel.org
      Cc: linux-sh@vger.kernel.org
      Cc: linuxppc-dev@lists.ozlabs.org
      Cc: sparclinux@vger.kernel.org
      Link: http://lkml.kernel.org/r/1453841853-11383-7-git-send-email-bp@alien8.de
      
      Signed-off-by: default avatarIngo Molnar <mingo@kernel.org>
      35d98e93