linux-toradex.git/include/linux/mm.h, branch v2.6.27.31

security: use mmap_min_addr indepedently of security models

2009-07-20T03:44:59+00:00

commit e0a94c2a63f2644826069044649669b5e7ca75d3 upstream.

This patch removes the dependency of mmap_min_addr on CONFIG_SECURITY.
It also sets a default mmap_min_addr of 4096.

mmapping of addresses below 4096 will only be possible for processes
with CAP_SYS_RAWIO.

Signed-off-by: Christoph Lameter 
Acked-by: Eric Paris 
Looks-ok-by: Linus Torvalds 
Signed-off-by: James Morris 
Signed-off-by: Greg Kroah-Hartman

mm: page_mkwrite change prototype to match fault

2009-05-20T05:20:09+00:00

commit c2ec175c39f62949438354f603f4aa170846aabb upstream


mm: page_mkwrite change prototype to match fault

Change the page_mkwrite prototype to take a struct vm_fault, and return
VM_FAULT_xxx flags.  There should be no functional change.

This makes it possible to return much more detailed error information to
the VM (and also can provide more information eg.  virtual_address to the
driver, which might be important in some special cases).

This is required for a subsequent fix.  And will also make it easier to
merge page_mkwrite() with fault() in future.

Signed-off-by: Nick Piggin 
Cc: Chris Mason 
Cc: Trond Myklebust 
Cc: Miklos Szeredi 
Cc: Steven Whitehouse 
Cc: Mark Fasheh 
Cc: Joel Becker 
Cc: Artem Bityutskiy 
Cc: Felix Blyakher 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds 
Signed-off-by: Greg Kroah-Hartman

mm: clean up for early_pfn_to_nid()

2009-03-17T00:52:45+00:00

commit f2dbcfa738368c8a40d4a5f0b65dc9879577cb21 upstream.

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: KAMEZAWA Hiroyuki 
Tested-by: KOSAKI Motohiro 
Reported-by: David Miller 
Cc: Mel Gorman 
Cc: Heiko Carstens 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds 
Signed-off-by: Greg Kroah-Hartman

mm: fix assertion

2009-01-18T18:35:44+00:00

commit 18e6959c385f3edf3991fa6662a53dac4eb10d5b upstream.

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: Nick Piggin 
Signed-off-by: Linus Torvalds 
Signed-off-by: Greg Kroah-Hartman

mm: VM_flags comment fixes

2008-08-16T23:45:56+00:00

Try to comment away a little of the confusion between mm's vm_area_struct
vm_flags and vmalloc's vm_struct flags: based on an idea by Ulrich Drepper.

Signed-off-by: Hugh Dickins 
Signed-off-by: Linus Torvalds

mm: Make generic weak get_user_pages_fast and EXPORT_GPL it

2008-08-12T07:52:53+00:00

Out of line get_user_pages_fast fallback implementation, make it a weak
symbol, get rid of CONFIG_HAVE_GET_USER_PAGES_FAST.

Export the symbol to modules so lguest can use it.

Signed-off-by: Nick Piggin 
Signed-off-by: Rusty Russell

mm: add zap_vma_ptes(): a library function to unmap driver ptes

2008-07-30T16:41:47+00:00

zap_vma_ptes() is intended to be used by drivers to unmap ptes assigned to the
driver private vmas.  This interface is similar to zap_page_range() but is
less general & less likely to be abused.

Needed by the GRU driver.

Signed-off-by: Jack Steiner 
Cc: Nick Piggin 
Cc: Hugh Dickins 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

mm: remove find_max_pfn_with_active_regions

2008-07-30T16:41:44+00:00

It has no user now

Also print out info about adding/removing active regions.

Signed-off-by: Yinghai Lu 
Acked-by: Mel Gorman 
Acked-by: Ingo Molnar 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

mmu-notifiers: add mm_take_all_locks() operation

2008-07-28T23:30:21+00:00

mm_take_all_locks holds off reclaim from an entire mm_struct.  This allows
mmu notifiers to register into the mm at any time with the guarantee that
no mmu operation is in progress on the mm.

This operation locks against the VM for all pte/vma/mm related operations
that could ever happen on a certain mm.  This includes vmtruncate,
try_to_unmap, and all page faults.

The caller must take the mmap_sem in write mode before calling
mm_take_all_locks().  The caller isn't allowed to release the mmap_sem
until mm_drop_all_locks() returns.

mmap_sem in write mode is required in order to block all operations that
could modify pagetables and free pages without need of altering the vma
layout (for example populate_range() with nonlinear vmas).  It's also
needed in write mode to avoid new anon_vmas to be associated with existing
vmas.

A single task can't take more than one mm_take_all_locks() in a row or it
would deadlock.

mm_take_all_locks() and mm_drop_all_locks are expensive operations that
may have to take thousand of locks.

mm_take_all_locks() can fail if it's interrupted by signals.

When mmu_notifier_register returns, we must be sure that the driver is
notified if some task is in the middle of a vmtruncate for the 'mm' where
the mmu notifier was registered (mmu_notifier_invalidate_range_start/end
is run around the vmtruncation but mmu_notifier_register can run after
mmu_notifier_invalidate_range_start and before
mmu_notifier_invalidate_range_end).  Same problem for rmap paths.  And
we've to remove page pinning to avoid replicating the tlb_gather logic
inside KVM (and GRU doesn't work well with page pinning regardless of
needing tlb_gather), so without mm_take_all_locks when vmtruncate frees
the page, kvm would have no way to notice that it mapped into sptes a page
that is going into the freelist without a chance of any further
mmu_notifier notification.

[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: Andrea Arcangeli 
Acked-by: Linus Torvalds 
Cc: Christoph Lameter 
Cc: Jack Steiner 
Cc: Robin Holt 
Cc: Nick Piggin 
Cc: Peter Zijlstra 
Cc: Kanoj Sarcar 
Cc: Roland Dreier 
Cc: Steve Wise 
Cc: Avi Kivity 
Cc: Hugh Dickins 
Cc: Rusty Russell 
Cc: Anthony Liguori 
Cc: Chris Wright 
Cc: Marcelo Tosatti 
Cc: Eric Dumazet 
Cc: "Paul E. McKenney" 
Cc: Izik Eidus 
Cc: Anthony Liguori 
Cc: Rik van Riel 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

make mm/memory.c:print_bad_pte() static

2008-07-26T19:00:12+00:00

This patch makes the needlessly global print_bad_pte() static.

Signed-off-by: Adrian Bunk 
Reviewed-by: KOSAKI Motohiro 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds