1. 12 1月, 2011 1 次提交
  2. 03 12月, 2010 1 次提交
    • J
      vmalloc: eagerly clear ptes on vunmap · 64141da5
      Jeremy Fitzhardinge 提交于
      On stock 2.6.37-rc4, running:
      
        # mount lilith:/export /mnt/lilith
        # find  /mnt/lilith/ -type f -print0 | xargs -0 file
      
      crashes the machine fairly quickly under Xen.  Often it results in oops
      messages, but the couple of times I tried just now, it just hung quietly
      and made Xen print some rude messages:
      
          (XEN) mm.c:2389:d80 Bad type (saw 7400000000000001 != exp
          3000000000000000) for mfn 1d7058 (pfn 18fa7)
          (XEN) mm.c:964:d80 Attempt to create linear p.t. with write perms
          (XEN) mm.c:2389:d80 Bad type (saw 7400000000000010 != exp
          1000000000000000) for mfn 1d2e04 (pfn 1d1fb)
          (XEN) mm.c:2965:d80 Error while pinning mfn 1d2e04
      
      Which means the domain tried to map a pagetable page RW, which would
      allow it to map arbitrary memory, so Xen stopped it.  This is because
      vm_unmap_ram() left some pages mapped in the vmalloc area after NFS had
      finished with them, and those pages got recycled as pagetable pages
      while still having these RW aliases.
      
      Removing those mappings immediately removes the Xen-visible aliases, and
      so it has no problem with those pages being reused as pagetable pages.
      Deferring the TLB flush doesn't upset Xen because it can flush the TLB
      itself as needed to maintain its invariants.
      
      When unmapping a region in the vmalloc space, clear the ptes
      immediately.  There's no point in deferring this because there's no
      amortization benefit.
      
      The TLBs are left dirty, and they are flushed lazily to amortize the
      cost of the IPIs.
      
      This specific motivation for this patch is an oops-causing regression
      since 2.6.36 when using NFS under Xen, triggered by the NFS client's use
      of vm_map_ram() introduced in 56e4ebf8 ("NFS: readdir with vmapped
      pages") .  XFS also uses vm_map_ram() and could cause similar problems.
      Signed-off-by: NJeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
      Cc: Nick Piggin <npiggin@kernel.dk>
      Cc: Bryan Schumaker <bjschuma@netapp.com>
      Cc: Trond Myklebust <Trond.Myklebust@netapp.com>
      Cc: Alex Elder <aelder@sgi.com>
      Cc: Dave Chinner <david@fromorbit.com>
      Cc: Christoph Hellwig <hch@lst.de>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      64141da5
  3. 30 11月, 2010 1 次提交
    • I
      xen: x86/32: perform initial startup on initial_page_table · 805e3f49
      Ian Campbell 提交于
      Only make swapper_pg_dir readonly and pinned when generic x86 architecture code
      (which also starts on initial_page_table) switches to it.  This helps ensure
      that the generic setup paths work on Xen unmodified. In particular
      clone_pgd_range writes directly to the destination pgd entries and is used to
      initialise swapper_pg_dir so we need to ensure that it remains writeable until
      the last possible moment during bring up.
      
      This is complicated slightly by the need to avoid sharing kernel PMD entries
      when running under Xen, therefore the Xen implementation must make a copy of
      the kernel PMD (which is otherwise referred to by both intial_page_table and
      swapper_pg_dir) before switching to swapper_pg_dir.
      Signed-off-by: NIan Campbell <ian.campbell@citrix.com>
      Cc: Borislav Petkov <bp@alien8.de>
      Cc: H. Peter Anvin <hpa@linux.intel.com>
      Cc: Jeremy Fitzhardinge <jeremy@goop.org>
      Signed-off-by: NJeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
      805e3f49
  4. 25 11月, 2010 1 次提交
    • I
      xen: x86/32: perform initial startup on initial_page_table · 5b5c1af1
      Ian Campbell 提交于
      Only make swapper_pg_dir readonly and pinned when generic x86 architecture code
      (which also starts on initial_page_table) switches to it.  This helps ensure
      that the generic setup paths work on Xen unmodified. In particular
      clone_pgd_range writes directly to the destination pgd entries and is used to
      initialise swapper_pg_dir so we need to ensure that it remains writeable until
      the last possible moment during bring up.
      
      This is complicated slightly by the need to avoid sharing kernel PMD entries
      when running under Xen, therefore the Xen implementation must make a copy of
      the kernel PMD (which is otherwise referred to by both intial_page_table and
      swapper_pg_dir) before switching to swapper_pg_dir.
      Signed-off-by: NIan Campbell <ian.campbell@citrix.com>
      Tested-by: NKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>
      Cc: Borislav Petkov <bp@alien8.de>
      Cc: H. Peter Anvin <hpa@linux.intel.com>
      Cc: Jeremy Fitzhardinge <jeremy@goop.org>
      Signed-off-by: NKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>
      5b5c1af1
  5. 13 11月, 2010 1 次提交
  6. 12 11月, 2010 1 次提交
  7. 30 10月, 2010 1 次提交
  8. 23 10月, 2010 16 次提交
  9. 21 10月, 2010 2 次提交
  10. 14 10月, 2010 1 次提交
    • J
      xen: Cope with unmapped pages when initializing kernel pagetable · fef5ba79
      Jeremy Fitzhardinge 提交于
      Xen requires that all pages containing pagetable entries to be mapped
      read-only.  If pages used for the initial pagetable are already mapped
      then we can change the mapping to RO.  However, if they are initially
      unmapped, we need to make sure that when they are later mapped, they
      are also mapped RO.
      
      We do this by knowing that the kernel pagetable memory is pre-allocated
      in the range e820_table_start - e820_table_end, so any pfn within this
      range should be mapped read-only.  However, the pagetable setup code
      early_ioremaps the pages to write their entries, so we must make sure
      that mappings created in the early_ioremap fixmap area are mapped RW.
      (Those mappings are removed before the pages are presented to Xen
      as pagetable pages.)
      Signed-off-by: NJeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
      LKML-Reference: <4CB63A80.8060702@goop.org>
      Cc: Yinghai Lu <yinghai@kernel.org>
      Signed-off-by: NH. Peter Anvin <hpa@linux.intel.com>
      fef5ba79
  11. 28 8月, 2010 1 次提交
  12. 24 8月, 2010 1 次提交
  13. 30 7月, 2010 1 次提交
  14. 27 7月, 2010 2 次提交
  15. 08 6月, 2010 4 次提交
  16. 30 3月, 2010 1 次提交
    • T
      include cleanup: Update gfp.h and slab.h includes to prepare for breaking... · 5a0e3ad6
      Tejun Heo 提交于
      include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h
      
      percpu.h is included by sched.h and module.h and thus ends up being
      included when building most .c files.  percpu.h includes slab.h which
      in turn includes gfp.h making everything defined by the two files
      universally available and complicating inclusion dependencies.
      
      percpu.h -> slab.h dependency is about to be removed.  Prepare for
      this change by updating users of gfp and slab facilities include those
      headers directly instead of assuming availability.  As this conversion
      needs to touch large number of source files, the following script is
      used as the basis of conversion.
      
        http://userweb.kernel.org/~tj/misc/slabh-sweep.py
      
      The script does the followings.
      
      * Scan files for gfp and slab usages and update includes such that
        only the necessary includes are there.  ie. if only gfp is used,
        gfp.h, if slab is used, slab.h.
      
      * When the script inserts a new include, it looks at the include
        blocks and try to put the new include such that its order conforms
        to its surrounding.  It's put in the include block which contains
        core kernel includes, in the same order that the rest are ordered -
        alphabetical, Christmas tree, rev-Xmas-tree or at the end if there
        doesn't seem to be any matching order.
      
      * If the script can't find a place to put a new include (mostly
        because the file doesn't have fitting include block), it prints out
        an error message indicating which .h file needs to be added to the
        file.
      
      The conversion was done in the following steps.
      
      1. The initial automatic conversion of all .c files updated slightly
         over 4000 files, deleting around 700 includes and adding ~480 gfp.h
         and ~3000 slab.h inclusions.  The script emitted errors for ~400
         files.
      
      2. Each error was manually checked.  Some didn't need the inclusion,
         some needed manual addition while adding it to implementation .h or
         embedding .c file was more appropriate for others.  This step added
         inclusions to around 150 files.
      
      3. The script was run again and the output was compared to the edits
         from #2 to make sure no file was left behind.
      
      4. Several build tests were done and a couple of problems were fixed.
         e.g. lib/decompress_*.c used malloc/free() wrappers around slab
         APIs requiring slab.h to be added manually.
      
      5. The script was run on all .h files but without automatically
         editing them as sprinkling gfp.h and slab.h inclusions around .h
         files could easily lead to inclusion dependency hell.  Most gfp.h
         inclusion directives were ignored as stuff from gfp.h was usually
         wildly available and often used in preprocessor macros.  Each
         slab.h inclusion directive was examined and added manually as
         necessary.
      
      6. percpu.h was updated not to include slab.h.
      
      7. Build test were done on the following configurations and failures
         were fixed.  CONFIG_GCOV_KERNEL was turned off for all tests (as my
         distributed build env didn't work with gcov compiles) and a few
         more options had to be turned off depending on archs to make things
         build (like ipr on powerpc/64 which failed due to missing writeq).
      
         * x86 and x86_64 UP and SMP allmodconfig and a custom test config.
         * powerpc and powerpc64 SMP allmodconfig
         * sparc and sparc64 SMP allmodconfig
         * ia64 SMP allmodconfig
         * s390 SMP allmodconfig
         * alpha SMP allmodconfig
         * um on x86_64 SMP allmodconfig
      
      8. percpu.h modifications were reverted so that it could be applied as
         a separate patch and serve as bisection point.
      
      Given the fact that I had only a couple of failures from tests on step
      6, I'm fairly confident about the coverage of this conversion patch.
      If there is a breakage, it's likely to be something in one of the arch
      headers which should be easily discoverable easily on most builds of
      the specific arch.
      Signed-off-by: NTejun Heo <tj@kernel.org>
      Guess-its-ok-by: NChristoph Lameter <cl@linux-foundation.org>
      Cc: Ingo Molnar <mingo@redhat.com>
      Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
      5a0e3ad6
  17. 28 2月, 2010 2 次提交
  18. 04 12月, 2009 1 次提交
    • I
      xen: correctly restore pfn_to_mfn_list_list after resume · fa24ba62
      Ian Campbell 提交于
      pvops kernels >= 2.6.30 can currently only be saved and restored once. The
      second attempt to save results in:
      
          ERROR Internal error: Frame# in pfn-to-mfn frame list is not in pseudophys
          ERROR Internal error: entry 0: p2m_frame_list[0] is 0xf2c2c2c2, max 0x120000
          ERROR Internal error: Failed to map/save the p2m frame list
      
      I finally narrowed it down to:
      
          commit cdaead6b
              Author: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
              Date:   Fri Feb 27 15:34:59 2009 -0800
      
                  xen: split construction of p2m mfn tables from registration
      
                  Build the p2m_mfn_list_list early with the rest of the p2m table, but
                  register it later when the real shared_info structure is in place.
      Signed-off-by: NJeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
      
      The unforeseen side-effect of this change was to cause the mfn list list to not
      be rebuilt on resume. Prior to this change it would have been rebuilt via
      xen_post_suspend() -> xen_setup_shared_info() -> xen_setup_mfn_list_list().
      
      Fix by explicitly calling xen_build_mfn_list_list() from xen_post_suspend().
      Signed-off-by: NIan Campbell <ian.campbell@citrix.com>
      Signed-off-by: NJeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
      Cc: Stable Kernel <stable@kernel.org>
      fa24ba62
  19. 24 9月, 2009 1 次提交