1. 16 9月, 2009 5 次提交
    • A
      HWPOISON: The high level memory error handler in the VM v7 · 6a46079c
      Andi Kleen 提交于
      Add the high level memory handler that poisons pages
      that got corrupted by hardware (typically by a two bit flip in a DIMM
      or a cache) on the Linux level. The goal is to prevent everyone
      from accessing these pages in the future.
      
      This done at the VM level by marking a page hwpoisoned
      and doing the appropriate action based on the type of page
      it is.
      
      The code that does this is portable and lives in mm/memory-failure.c
      
      To quote the overview comment:
      
      High level machine check handler. Handles pages reported by the
      hardware as being corrupted usually due to a 2bit ECC memory or cache
      failure.
      
      This focuses on pages detected as corrupted in the background.
      When the current CPU tries to consume corruption the currently
      running process can just be killed directly instead. This implies
      that if the error cannot be handled for some reason it's safe to
      just ignore it because no corruption has been consumed yet. Instead
      when that happens another machine check will happen.
      
      Handles page cache pages in various states. The tricky part
      here is that we can access any page asynchronous to other VM
      users, because memory failures could happen anytime and anywhere,
      possibly violating some of their assumptions. This is why this code
      has to be extremely careful. Generally it tries to use normal locking
      rules, as in get the standard locks, even if that means the
      error handling takes potentially a long time.
      
      Some of the operations here are somewhat inefficient and have non
      linear algorithmic complexity, because the data structures have not
      been optimized for this case. This is in particular the case
      for the mapping from a vma to a process. Since this case is expected
      to be rare we hope we can get away with this.
      
      There are in principle two strategies to kill processes on poison:
      - just unmap the data and wait for an actual reference before
      killing
      - kill as soon as corruption is detected.
      Both have advantages and disadvantages and should be used
      in different situations. Right now both are implemented and can
      be switched with a new sysctl vm.memory_failure_early_kill
      The default is early kill.
      
      The patch does some rmap data structure walking on its own to collect
      processes to kill. This is unusual because normally all rmap data structure
      knowledge is in rmap.c only. I put it here for now to keep
      everything together and rmap knowledge has been seeping out anyways
      
      Includes contributions from Johannes Weiner, Chris Mason, Fengguang Wu,
      Nick Piggin (who did a lot of great work) and others.
      
      Cc: npiggin@suse.de
      Cc: riel@redhat.com
      Signed-off-by: NAndi Kleen <ak@linux.intel.com>
      Acked-by: NRik van Riel <riel@redhat.com>
      Reviewed-by: NHidehiro Kawai <hidehiro.kawai.ez@hitachi.com>
      6a46079c
    • A
      HWPOISON: Define a new error_remove_page address space op for async truncation · 25718736
      Andi Kleen 提交于
      Truncating metadata pages is not safe right now before
      we haven't audited all file systems.
      
      To enable truncation only for data address space define
      a new address_space callback error_remove_page.
      
      This is used for memory_failure.c memory error handling.
      
      This can be then set to truncate_inode_page()
      
      This patch just defines the new operation and adds documentation.
      
      Callers and users come in followon patches.
      Signed-off-by: NAndi Kleen <ak@linux.intel.com>
      25718736
    • W
      HWPOISON: Add invalidate_inode_page · 83f78668
      Wu Fengguang 提交于
      Add a simple way to invalidate a single page
      This is just a refactoring of the truncate.c code.
      Originally from Fengguang, modified by Andi Kleen.
      Signed-off-by: NAndi Kleen <ak@linux.intel.com>
      83f78668
    • N
      HWPOISON: Refactor truncate to allow direct truncating of page v2 · 750b4987
      Nick Piggin 提交于
      Extract out truncate_inode_page() out of the truncate path so that
      it can be used by memory-failure.c
      
      [AK: description, headers, fix typos]
      v2: Some white space changes from Fengguang Wu
      Signed-off-by: NAndi Kleen <ak@linux.intel.com>
      750b4987
    • A
      HWPOISON: Add basic support for poisoned pages in fault handler v3 · d1737fdb
      Andi Kleen 提交于
      - Add a new VM_FAULT_HWPOISON error code to handle_mm_fault. Right now
      architectures have to explicitely enable poison page support, so
      this is forward compatible to all architectures. They only need
      to add it when they enable poison page support.
      - Add poison page handling in swap in fault code
      
      v2: Add missing delayacct_clear_flag (Hidehiro Kawai)
      v3: Really use delayacct_clear_flag (Hidehiro Kawai)
      Signed-off-by: NAndi Kleen <ak@linux.intel.com>
      d1737fdb
  2. 17 8月, 2009 1 次提交
    • E
      Security/SELinux: seperate lsm specific mmap_min_addr · 788084ab
      Eric Paris 提交于
      Currently SELinux enforcement of controls on the ability to map low memory
      is determined by the mmap_min_addr tunable.  This patch causes SELinux to
      ignore the tunable and instead use a seperate Kconfig option specific to how
      much space the LSM should protect.
      
      The tunable will now only control the need for CAP_SYS_RAWIO and SELinux
      permissions will always protect the amount of low memory designated by
      CONFIG_LSM_MMAP_MIN_ADDR.
      
      This allows users who need to disable the mmap_min_addr controls (usual reason
      being they run WINE as a non-root user) to do so and still have SELinux
      controls preventing confined domains (like a web server) from being able to
      map some area of low memory.
      Signed-off-by: NEric Paris <eparis@redhat.com>
      Signed-off-by: NJames Morris <jmorris@namei.org>
      788084ab
  3. 06 8月, 2009 1 次提交
    • E
      Security/SELinux: seperate lsm specific mmap_min_addr · a2551df7
      Eric Paris 提交于
      Currently SELinux enforcement of controls on the ability to map low memory
      is determined by the mmap_min_addr tunable.  This patch causes SELinux to
      ignore the tunable and instead use a seperate Kconfig option specific to how
      much space the LSM should protect.
      
      The tunable will now only control the need for CAP_SYS_RAWIO and SELinux
      permissions will always protect the amount of low memory designated by
      CONFIG_LSM_MMAP_MIN_ADDR.
      
      This allows users who need to disable the mmap_min_addr controls (usual reason
      being they run WINE as a non-root user) to do so and still have SELinux
      controls preventing confined domains (like a web server) from being able to
      map some area of low memory.
      Signed-off-by: NEric Paris <eparis@redhat.com>
      Signed-off-by: NJames Morris <jmorris@namei.org>
      a2551df7
  4. 26 6月, 2009 1 次提交
  5. 22 6月, 2009 1 次提交
  6. 17 6月, 2009 7 次提交
  7. 15 6月, 2009 1 次提交
  8. 04 6月, 2009 1 次提交
  9. 18 5月, 2009 1 次提交
    • Y
      mm, x86: remove MEMORY_HOTPLUG_RESERVE related code · 888a589f
      Yinghai Lu 提交于
      after:
      
       | commit b263295d
       | Author: Christoph Lameter <clameter@sgi.com>
       | Date:   Wed Jan 30 13:30:47 2008 +0100
       |
       |    x86: 64-bit, make sparsemem vmemmap the only memory model
      
      we don't have MEMORY_HOTPLUG_RESERVE anymore.
      
      Historically, x86-64 had an architecture-specific method for memory hotplug
      whereby it scanned the SRAT for physical memory ranges that could be
      potentially used for memory hot-add later. By reserving those ranges
      without physical memory, the memmap would be allocated and left dormant
      until needed. This depended on the DISCONTIG memory model which has been
      removed so the code implementing HOTPLUG_RESERVE is now dead.
      
      This patch removes the dead code used by MEMORY_HOTPLUG_RESERVE.
      
      (Changelog authored by Mel.)
      
      v2: updated changelog, and remove hotadd= in doc
      
      [ Impact: remove dead code ]
      Signed-off-by: NYinghai Lu <yinghai@kernel.org>
      Reviewed-by: NChristoph Lameter <cl@linux-foundation.org>
      Reviewed-by: NMel Gorman <mel@csn.ul.ie>
      Workflow-found-OK-by: NAndrew Morton <akpm@linux-foundation.org>
      LKML-Reference: <4A0C4910.7090508@kernel.org>
      Signed-off-by: NIngo Molnar <mingo@elte.hu>
      888a589f
  10. 24 4月, 2009 1 次提交
  11. 08 4月, 2009 2 次提交
  12. 07 4月, 2009 1 次提交
  13. 03 4月, 2009 1 次提交
    • D
      nommu: fix a number of issues with the per-MM VMA patch · 33e5d769
      David Howells 提交于
      Fix a number of issues with the per-MM VMA patch:
      
       (1) Make mmap_pages_allocated an atomic_long_t, just in case this is used on
           a NOMMU system with more than 2G pages.  Makes no difference on a 32-bit
           system.
      
       (2) Report vma->vm_pgoff * PAGE_SIZE as a 64-bit value, not a 32-bit value,
           lest it overflow.
      
       (3) Move the allocation of the vm_area_struct slab back for fork.c.
      
       (4) Use KMEM_CACHE() for both vm_area_struct and vm_region slabs.
      
       (5) Use BUG_ON() rather than if () BUG().
      
       (6) Make the default validate_nommu_regions() a static inline rather than a
           #define.
      
       (7) Make free_page_series()'s objection to pages with a refcount != 1 more
           informative.
      
       (8) Adjust the __put_nommu_region() banner comment to indicate that the
           semaphore must be held for writing.
      
       (9) Limit the number of warnings about munmaps of non-mmapped regions.
      Reported-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NDavid Howells <dhowells@redhat.com>
      Cc: Greg Ungerer <gerg@snapgear.com>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      33e5d769
  14. 01 4月, 2009 2 次提交
  15. 14 3月, 2009 1 次提交
  16. 13 3月, 2009 1 次提交
  17. 19 2月, 2009 2 次提交
    • K
      mm: clean up for early_pfn_to_nid() · f2dbcfa7
      KAMEZAWA Hiroyuki 提交于
      What's happening is that the assertion in mm/page_alloc.c:move_freepages()
      is triggering:
      
      	BUG_ON(page_zone(start_page) != page_zone(end_page));
      
      Once I knew this is what was happening, I added some annotations:
      
      	if (unlikely(page_zone(start_page) != page_zone(end_page))) {
      		printk(KERN_ERR "move_freepages: Bogus zones: "
      		       "start_page[%p] end_page[%p] zone[%p]\n",
      		       start_page, end_page, zone);
      		printk(KERN_ERR "move_freepages: "
      		       "start_zone[%p] end_zone[%p]\n",
      		       page_zone(start_page), page_zone(end_page));
      		printk(KERN_ERR "move_freepages: "
      		       "start_pfn[0x%lx] end_pfn[0x%lx]\n",
      		       page_to_pfn(start_page), page_to_pfn(end_page));
      		printk(KERN_ERR "move_freepages: "
      		       "start_nid[%d] end_nid[%d]\n",
      		       page_to_nid(start_page), page_to_nid(end_page));
       ...
      
      And here's what I got:
      
      	move_freepages: Bogus zones: start_page[2207d0000] end_page[2207dffc0] zone[fffff8103effcb00]
      	move_freepages: start_zone[fffff8103effcb00] end_zone[fffff8003fffeb00]
      	move_freepages: start_pfn[0x81f600] end_pfn[0x81f7ff]
      	move_freepages: start_nid[1] end_nid[0]
      
      My memory layout on this box is:
      
      [    0.000000] Zone PFN ranges:
      [    0.000000]   Normal   0x00000000 -> 0x0081ff5d
      [    0.000000] Movable zone start PFN for each node
      [    0.000000] early_node_map[8] active PFN ranges
      [    0.000000]     0: 0x00000000 -> 0x00020000
      [    0.000000]     1: 0x00800000 -> 0x0081f7ff
      [    0.000000]     1: 0x0081f800 -> 0x0081fe50
      [    0.000000]     1: 0x0081fed1 -> 0x0081fed8
      [    0.000000]     1: 0x0081feda -> 0x0081fedb
      [    0.000000]     1: 0x0081fedd -> 0x0081fee5
      [    0.000000]     1: 0x0081fee7 -> 0x0081ff51
      [    0.000000]     1: 0x0081ff59 -> 0x0081ff5d
      
      So it's a block move in that 0x81f600-->0x81f7ff region which triggers
      the problem.
      
      This patch:
      
      Declaration of early_pfn_to_nid() is scattered over per-arch include
      files, and it seems it's complicated to know when the declaration is used.
       I think it makes fix-for-memmap-init not easy.
      
      This patch moves all declaration to include/linux/mm.h
      
      After this,
        if !CONFIG_NODES_POPULATES_NODE_MAP && !CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID
           -> Use static definition in include/linux/mm.h
        else if !CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID
           -> Use generic definition in mm/page_alloc.c
        else
           -> per-arch back end function will be called.
      Signed-off-by: NKAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
      Tested-by: NKOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
      Reported-by: NDavid Miller <davem@davemlloft.net>
      Cc: Mel Gorman <mel@csn.ul.ie>
      Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
      Cc: <stable@kernel.org>		[2.6.25.x, 2.6.26.x, 2.6.27.x, 2.6.28.x]
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      f2dbcfa7
    • N
      mm: task dirty accounting fix · 1cf6e7d8
      Nick Piggin 提交于
      YAMAMOTO-san noticed that task_dirty_inc doesn't seem to be called properly for
      cases where set_page_dirty is not used to dirty a page (eg. mark_buffer_dirty).
      
      Additionally, there is some inconsistency about when task_dirty_inc is
      called.  It is used for dirty balancing, however it even gets called for
      __set_page_dirty_no_writeback.
      
      So rather than increment it in a set_page_dirty wrapper, move it down to
      exactly where the dirty page accounting stats are incremented.
      
      Cc: YAMAMOTO Takashi <yamamoto@valinux.co.jp>
      Signed-off-by: NNick Piggin <npiggin@suse.de>
      Acked-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      1cf6e7d8
  18. 11 2月, 2009 2 次提交
    • M
      x86, ptrace, mm: fix double-free on race · 9f339e70
      Markus Metzger 提交于
      Ptrace_detach() races with __ptrace_unlink() if the traced task is
      reaped while detaching. This might cause a double-free of the BTS
      buffer.
      
      Change the ptrace_detach() path to only do the memory accounting in
      ptrace_bts_detach() and leave the buffer free to ptrace_bts_untrace()
      which will be called from __ptrace_unlink().
      
      The fix follows a proposal from Oleg Nesterov.
      Reported-by: NOleg Nesterov <oleg@redhat.com>
      Signed-off-by: NMarkus Metzger <markus.t.metzger@intel.com>
      Signed-off-by: NIngo Molnar <mingo@elte.hu>
      9f339e70
    • M
      Do not account for the address space used by hugetlbfs using VM_ACCOUNT · 5a6fe125
      Mel Gorman 提交于
      When overcommit is disabled, the core VM accounts for pages used by anonymous
      shared, private mappings and special mappings. It keeps track of VMAs that
      should be accounted for with VM_ACCOUNT and VMAs that never had a reserve
      with VM_NORESERVE.
      
      Overcommit for hugetlbfs is much riskier than overcommit for base pages
      due to contiguity requirements. It avoids overcommiting on both shared and
      private mappings using reservation counters that are checked and updated
      during mmap(). This ensures (within limits) that hugepages exist in the
      future when faults occurs or it is too easy to applications to be SIGKILLed.
      
      As hugetlbfs makes its own reservations of a different unit to the base page
      size, VM_ACCOUNT should never be set. Even if the units were correct, we would
      double account for the usage in the core VM and hugetlbfs. VM_NORESERVE may
      be set because an application can request no reserves be made for hugetlbfs
      at the risk of getting killed later.
      
      With commit fc8744ad, VM_NORESERVE and
      VM_ACCOUNT are getting unconditionally set for hugetlbfs-backed mappings. This
      breaks the accounting for both the core VM and hugetlbfs, can trigger an
      OOM storm when hugepage pools are too small lockups and corrupted counters
      otherwise are used. This patch brings hugetlbfs more in line with how the
      core VM treats VM_NORESERVE but prevents VM_ACCOUNT being set.
      Signed-off-by: NMel Gorman <mel@csn.ul.ie>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      5a6fe125
  19. 14 1月, 2009 1 次提交
    • N
      mm: fix assertion · 18e6959c
      Nick Piggin 提交于
      This assertion is incorrect for lockless pagecache.  By definition if we
      have an unpinned page that we are trying to take a speculative reference
      to, it may become the tail of a compound page at any time (if it is
      freed, then reallocated as a compound page).
      
      It was still a valid assertion for the vmscan.c LRU isolation case, but
      it doesn't seem incredibly helpful...  if somebody wants it, they can
      put it back directly where it applies in the vmscan code.
      Signed-off-by: NNick Piggin <npiggin@suse.de>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      18e6959c
  20. 08 1月, 2009 1 次提交
    • D
      NOMMU: Make VMAs per MM as for MMU-mode linux · 8feae131
      David Howells 提交于
      Make VMAs per mm_struct as for MMU-mode linux.  This solves two problems:
      
       (1) In SYSV SHM where nattch for a segment does not reflect the number of
           shmat's (and forks) done.
      
       (2) In mmap() where the VMA's vm_mm is set to point to the parent mm by an
           exec'ing process when VM_EXECUTABLE is specified, regardless of the fact
           that a VMA might be shared and already have its vm_mm assigned to another
           process or a dead process.
      
      A new struct (vm_region) is introduced to track a mapped region and to remember
      the circumstances under which it may be shared and the vm_list_struct structure
      is discarded as it's no longer required.
      
      This patch makes the following additional changes:
      
       (1) Regions are now allocated with alloc_pages() rather than kmalloc() and
           with no recourse to __GFP_COMP, so the pages are not composite.  Instead,
           each page has a reference on it held by the region.  Anything else that is
           interested in such a page will have to get a reference on it to retain it.
           When the pages are released due to unmapping, each page is passed to
           put_page() and will be freed when the page usage count reaches zero.
      
       (2) Excess pages are trimmed after an allocation as the allocation must be
           made as a power-of-2 quantity of pages.
      
       (3) VMAs are added to the parent MM's R/B tree and mmap lists.  As an MM may
           end up with overlapping VMAs within the tree, the VMA struct address is
           appended to the sort key.
      
       (4) Non-anonymous VMAs are now added to the backing inode's prio list.
      
       (5) Holes may be punched in anonymous VMAs with munmap(), releasing parts of
           the backing region.  The VMA and region structs will be split if
           necessary.
      
       (6) sys_shmdt() only releases one attachment to a SYSV IPC shared memory
           segment instead of all the attachments at that addresss.  Multiple
           shmat()'s return the same address under NOMMU-mode instead of different
           virtual addresses as under MMU-mode.
      
       (7) Core dumping for ELF-FDPIC requires fewer exceptions for NOMMU-mode.
      
       (8) /proc/maps is now the global list of mapped regions, and may list bits
           that aren't actually mapped anywhere.
      
       (9) /proc/meminfo gains a line (tagged "MmapCopy") that indicates the amount
           of RAM currently allocated by mmap to hold mappable regions that can't be
           mapped directly.  These are copies of the backing device or file if not
           anonymous.
      
      These changes make NOMMU mode more similar to MMU mode.  The downside is that
      NOMMU mode requires some extra memory to track things over NOMMU without this
      patch (VMAs are no longer shared, and there are now region structs).
      Signed-off-by: NDavid Howells <dhowells@redhat.com>
      Tested-by: NMike Frysinger <vapier.adi@gmail.com>
      Acked-by: NPaul Mundt <lethal@linux-sh.org>
      8feae131
  21. 07 1月, 2009 1 次提交
    • N
      mm: invoke oom-killer from page fault · 1c0fe6e3
      Nick Piggin 提交于
      Rather than have the pagefault handler kill a process directly if it gets
      a VM_FAULT_OOM, have it call into the OOM killer.
      
      With increasingly sophisticated oom behaviour (cpusets, memory cgroups,
      oom killing throttling, oom priority adjustment or selective disabling,
      panic on oom, etc), it's silly to unconditionally kill the faulting
      process at page fault time.  Create a hook for pagefault oom path to call
      into instead.
      
      Only converted x86 and uml so far.
      
      [akpm@linux-foundation.org: make __out_of_memory() static]
      [akpm@linux-foundation.org: fix comment]
      Signed-off-by: NNick Piggin <npiggin@suse.de>
      Cc: Jeff Dike <jdike@addtoit.com>
      Acked-by: NIngo Molnar <mingo@elte.hu>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      1c0fe6e3
  22. 20 12月, 2008 5 次提交