1. 18 7月, 2017 1 次提交
    • M
      powerpc/mm: Mark __init memory no-execute when STRICT_KERNEL_RWX=y · 029d9252
      Michael Ellerman 提交于
      Currently even with STRICT_KERNEL_RWX we leave the __init text marked
      executable after init, which is bad.
      
      Add a hook to mark it NX (no-execute) before we free it, and implement
      it for radix and hash.
      
      Note that we use __init_end as the end address, not _einittext,
      because overlaps_kernel_text() uses __init_end, because there are
      additional executable sections other than .init.text between
      __init_begin and __init_end.
      
      Tested on radix and hash with:
      
        0:mon> p $__init_begin
        *** 400 exception occurred
      
      Fixes: 1e0fc9d1 ("powerpc/Kconfig: Enable STRICT_KERNEL_RWX for some configs")
      Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
      029d9252
  2. 04 7月, 2017 2 次提交
  3. 02 7月, 2017 1 次提交
  4. 23 6月, 2017 1 次提交
    • B
      powerpc/mm: Trace tlbie(l) instructions · 0428491c
      Balbir Singh 提交于
      Add a trace point for tlbie(l) (Translation Lookaside Buffer Invalidate
      Entry (Local)) instructions.
      
      The tlbie instruction has changed over the years, so not all versions
      accept the same operands. Use the ISA v3 field operands because they are
      the most verbose, we may change them in future.
      
      Example output:
      
        qemu-system-ppc-5371  [016]  1412.369519: tlbie:
        	tlbie with lpid 0, local 1, rb=67bd8900174c11c1, rs=0, ric=0 prs=0 r=0
      Signed-off-by: NBalbir Singh <bsingharora@gmail.com>
      [mpe: Add some missing trace_tlbie()s, reword change log]
      Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
      0428491c
  5. 05 6月, 2017 1 次提交
    • B
      powerpc/mm/book(e)(3s)/64: Add page table accounting · de3b8761
      Balbir Singh 提交于
      Introduce a helper pgtable_gfp_flags() which
      just returns the current gfp flags and adds
      __GFP_ACCOUNT to account for page table allocation.
      The generic helper is added to include/asm/pgalloc.h
      and has two variants - WARNING ugly bits ahead
      
      1. If the header is included from a module, no check
      for mm == &init_mm is done, since init_mm is not
      exported
      2. For kernel includes, the check is done and required
      see (3e79ec7d arch: x86: charge page tables to kmemcg)
      
      The fundamental assumption is that no module should be
      doing pgd/pud/pmd and pte alloc's on behalf of init_mm
      directly.
      
      NOTE: This adds an overhead to pmd/pud/pgd allocations
      similar to x86.  The other alternative was to implement
      pmd_alloc_kernel/pud_alloc_kernel and pgd_alloc_kernel
      with their offset variants.
      
      For 4k page size, pte_alloc_one no longer calls
      pte_alloc_one_kernel.
      Signed-off-by: NBalbir Singh <bsingharora@gmail.com>
      Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
      de3b8761
  6. 31 1月, 2017 1 次提交
  7. 30 1月, 2017 1 次提交
    • A
      powerpc/powernv: Initialise nest mmu · 1d0761d2
      Alistair Popple 提交于
      POWER9 contains an off core mmu called the nest mmu (NMMU). This is
      used by other hardware units on the chip to translate virtual
      addresses into real addresses. The unit attempting an address
      translation provides the majority of the context required for the
      translation request except for the base address of the partition table
      (ie. the PTCR) which needs to be programmed into the NMMU.
      
      This patch adds a call to OPAL to set the PTCR for the nest mmu in
      opal_init().
      Signed-off-by: NAlistair Popple <alistair@popple.id.au>
      Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
      1d0761d2
  8. 23 11月, 2016 1 次提交
    • P
      powerpc/64: Provide functions for accessing POWER9 partition table · 9d661958
      Paul Mackerras 提交于
      POWER9 requires the host to set up a partition table, which is a
      table in memory indexed by logical partition ID (LPID) which
      contains the pointers to page tables and process tables for the
      host and each guest.
      
      This factors out the initialization of the partition table into
      a single function.  This code was previously duplicated between
      hash_utils_64.c and pgtable-radix.c.
      
      This provides a function for setting a partition table entry,
      which is used in early MMU initialization, and will be used by
      KVM whenever a guest is created.  This function includes a tlbie
      instruction which will flush all TLB entries for the LPID and
      all caches of the partition table entry for the LPID, across the
      system.
      
      This also moves a call to memblock_set_current_limit(), which was
      in radix_init_partition_table(), but has nothing to do with the
      partition table.  By analogy with the similar code for hash, the
      call gets moved to near the end of radix__early_init_mmu().  It
      now gets called when running as a guest, whereas previously it
      would only be called if the kernel is running as the host.
      Signed-off-by: NPaul Mackerras <paulus@ozlabs.org>
      Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
      9d661958
  9. 25 6月, 2016 1 次提交
    • M
      tree wide: get rid of __GFP_REPEAT for order-0 allocations part I · 32d6bd90
      Michal Hocko 提交于
      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.orgSigned-off-by: NMichal 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: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      32d6bd90
  10. 11 5月, 2016 6 次提交
  11. 01 5月, 2016 12 次提交
  12. 18 3月, 2016 1 次提交
    • J
      mm: introduce page reference manipulation functions · fe896d18
      Joonsoo Kim 提交于
      The success of CMA allocation largely depends on the success of
      migration and key factor of it is page reference count.  Until now, page
      reference is manipulated by direct calling atomic functions so we cannot
      follow up who and where manipulate it.  Then, it is hard to find actual
      reason of CMA allocation failure.  CMA allocation should be guaranteed
      to succeed so finding offending place is really important.
      
      In this patch, call sites where page reference is manipulated are
      converted to introduced wrapper function.  This is preparation step to
      add tracepoint to each page reference manipulation function.  With this
      facility, we can easily find reason of CMA allocation failure.  There is
      no functional change in this patch.
      
      In addition, this patch also converts reference read sites.  It will
      help a second step that renames page._count to something else and
      prevents later attempt to direct access to it (Suggested by Andrew).
      Signed-off-by: NJoonsoo Kim <iamjoonsoo.kim@lge.com>
      Acked-by: NMichal Nazarewicz <mina86@mina86.com>
      Acked-by: NVlastimil Babka <vbabka@suse.cz>
      Cc: Minchan Kim <minchan@kernel.org>
      Cc: Mel Gorman <mgorman@techsingularity.net>
      Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
      Cc: Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com>
      Cc: Steven Rostedt <rostedt@goodmis.org>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      fe896d18
  13. 03 3月, 2016 1 次提交
  14. 29 2月, 2016 1 次提交
  15. 27 2月, 2016 1 次提交
    • P
      powerpc/mm/book3s-64: Free up 7 high-order bits in the Linux PTE · f1a9ae03
      Paul Mackerras 提交于
      This frees up bits 57-63 in the Linux PTE on 64-bit Book 3S machines.
      In the 4k page case, this is done just by reducing the size of the
      RPN field to 39 bits, giving 51-bit real addresses.  In the 64k page
      case, we had 10 unused bits in the middle of the PTE, so this moves
      the RPN field down 10 bits to make use of those unused bits.  This
      means the RPN field is now 3 bits larger at 37 bits, giving 53-bit
      real addresses in the normal case, or 49-bit real addresses for the
      special 4k PFN case.
      
      We are doing this in order to be able to move some other PTE bits
      into the positions where PowerISA V3.0 processors will expect to
      find them in radix-tree mode.  Ultimately we will be able to move
      the RPN field to lower bit positions and make it larger.
      Signed-off-by: NPaul Mackerras <paulus@samba.org>
      Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
      f1a9ae03
  16. 15 2月, 2016 1 次提交
    • A
      powerpc/mm: Fix Multi hit ERAT cause by recent THP update · c777e2a8
      Aneesh Kumar K.V 提交于
      With ppc64 we use the deposited pgtable_t to store the hash pte slot
      information. We should not withdraw the deposited pgtable_t without
      marking the pmd none. This ensure that low level hash fault handling
      will skip this huge pte and we will handle them at upper levels.
      
      Recent change to pmd splitting changed the above in order to handle the
      race between pmd split and exit_mmap. The race is explained below.
      
      Consider following race:
      
      		CPU0				CPU1
      shrink_page_list()
        add_to_swap()
          split_huge_page_to_list()
            __split_huge_pmd_locked()
              pmdp_huge_clear_flush_notify()
      	// pmd_none() == true
      					exit_mmap()
      					  unmap_vmas()
      					    zap_pmd_range()
      					      // no action on pmd since pmd_none() == true
      	pmd_populate()
      
      As result the THP will not be freed. The leak is detected by check_mm():
      
      	BUG: Bad rss-counter state mm:ffff880058d2e580 idx:1 val:512
      
      The above required us to not mark pmd none during a pmd split.
      
      The fix for ppc is to clear the huge pte of _PAGE_USER, so that low
      level fault handling code skip this pte. At higher level we do take ptl
      lock. That should serialze us against the pmd split. Once the lock is
      acquired we do check the pmd again using pmd_same. That should always
      return false for us and hence we should retry the access. We do the
      pmd_same check in all case after taking plt with
      THP (do_huge_pmd_wp_page, do_huge_pmd_numa_page and
      huge_pmd_set_accessed)
      
      Also make sure we wait for irq disable section in other cpus to finish
      before flipping a huge pte entry with a regular pmd entry. Code paths
      like find_linux_pte_or_hugepte depend on irq disable to get
      a stable pte_t pointer. A parallel thp split need to make sure we
      don't convert a pmd pte to a regular pmd entry without waiting for the
      irq disable section to finish.
      
      Fixes: eef1b3ba ("thp: implement split_huge_pmd()")
      Acked-by: NKirill A. Shutemov <kirill.shutemov@linux.intel.com>
      Signed-off-by: NAneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
      Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
      c777e2a8
  17. 16 1月, 2016 1 次提交
  18. 14 12月, 2015 4 次提交
  19. 08 8月, 2015 1 次提交
  20. 25 6月, 2015 1 次提交