linux/mm
Hugh Dickins aeed5fce37 x86: fix PAE pmd_bad bootup warning
Fix warning from pmd_bad() at bootup on a HIGHMEM64G HIGHPTE x86_32.

That came from 9fc34113f6 x86: debug pmd_bad();
but we understand now that the typecasting was wrong for PAE in the previous
version: pagetable pages above 4GB looked bad and stopped Arjan from booting.

And revert that cded932b75 x86: fix pmd_bad
and pud_bad to support huge pages.  It was the wrong way round: we shouldn't
weaken every pmd_bad and pud_bad check to let huge pages slip through - in
part they check that we _don't_ have a huge page where it's not expected.

Put the x86 pmd_bad() and pud_bad() definitions back to what they have long
been: they can be improved (x86_32 should use PTE_MASK, to stop PAE thinking
junk in the upper word is good; and x86_64 should follow x86_32's stricter
comparison, to stop thinking any subset of required bits is good); but that
should be a later patch.

Fix Hans' good observation that follow_page() will never find pmd_huge()
because that would have already failed the pmd_bad test: test pmd_huge in
between the pmd_none and pmd_bad tests.  Tighten x86's pmd_huge() check?
No, once it's a hugepage entry, it can get quite far from a good pmd: for
example, PROT_NONE leaves it with only ACCESSED of the KERN_PGTABLE bits.

However... though follow_page() contains this and another test for huge
pages, so it's nice to keep it working on them, where does it actually get
called on a huge page?  get_user_pages() checks is_vm_hugetlb_page(vma) to
to call alternative hugetlb processing, as does unmap_vmas() and others.

Signed-off-by: Hugh Dickins <hugh@veritas.com>
Earlier-version-tested-by: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Jeff Chua <jeff.chua.linux@gmail.com>
Cc: Hans Rosenfeld <hans.rosenfeld@amd.com>
Cc: Arjan van de Ven <arjan@linux.intel.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-05-06 13:08:58 -07:00
..
allocpercpu.c cpumask: Cleanup more uses of CPU_MASK and NODE_MASK 2008-04-19 19:44:58 +02:00
backing-dev.c mm: bdi: move statistics to debugfs 2008-04-30 08:29:50 -07:00
bootmem.c memory hotplug: make alloc_bootmem_section() 2008-04-28 08:58:25 -07:00
bounce.c block: Initial support for data-less (or empty) barrier support 2007-10-16 11:03:56 +02:00
dmapool.c dmapool: enable debugging for CONFIG_SLUB_DEBUG_ON too 2008-04-28 08:58:20 -07:00
fadvise.c xip: support non-struct page backed memory 2008-04-28 08:58:23 -07:00
filemap_xip.c xip: support non-struct page backed memory 2008-04-28 08:58:23 -07:00
filemap.c mm: rotate_reclaimable_page() cleanup 2008-04-28 08:58:20 -07:00
fremap.c mm: fix various kernel-doc comments 2008-03-19 18:53:35 -07:00
highmem.c mm: highmem kernel-doc additions 2008-03-19 18:53:35 -07:00
hugetlb.c page allocator: explicitly retry hugepage allocations 2008-04-29 08:05:58 -07:00
internal.h memory hotplug: free memmaps allocated by bootmem 2008-04-28 08:58:26 -07:00
Kconfig PAGEFLAGS_EXTENDED and separate page flags for Head and Tail 2008-04-28 08:58:22 -07:00
maccess.c kgdb: fix optional arch functions and probe_kernel_* 2008-04-17 20:05:39 +02:00
madvise.c xip: support non-struct page backed memory 2008-04-28 08:58:23 -07:00
Makefile uaccess: add probe_kernel_write() 2008-04-17 20:05:36 +02:00
memcontrol.c memcg: simple stats for memory resource controller 2008-05-01 08:04:02 -07:00
memory_hotplug.c mm/memory_hotplug.c must #include "internal.h" 2008-04-28 13:44:29 -07:00
memory.c x86: fix PAE pmd_bad bootup warning 2008-05-06 13:08:58 -07:00
mempolicy.c mempolicy: use struct mempolicy pointer in shmem_sb_info 2008-04-28 08:58:25 -07:00
mempool.c spelling fixes: mm/ 2007-10-20 01:27:18 +02:00
migrate.c mm: fix warning on memory offline 2008-04-30 08:29:55 -07:00
mincore.c mm: remove nopage 2008-04-28 08:58:18 -07:00
mlock.c do not limit locked memory when RLIMIT_MEMLOCK is RLIM_INFINITY 2007-07-16 09:05:37 -07:00
mmap.c procfs task exe symlink 2008-04-29 08:06:17 -07:00
mmzone.c mm: filter based on a nodemask as well as a gfp_mask 2008-04-28 08:58:19 -07:00
mprotect.c fix mprotect vma_wants_writenotify prot 2007-10-23 08:32:06 -07:00
mremap.c sparse pointer use of zero as null 2007-10-18 14:37:31 -07:00
msync.c Detach sched.h from mm.h 2007-05-21 09:18:19 -07:00
nommu.c procfs task exe symlink 2008-04-29 08:06:17 -07:00
oom_kill.c oom_kill: remove unused parameter in badness() 2008-04-28 08:58:26 -07:00
page_alloc.c infrastructure to debug (dynamic) objects 2008-04-30 08:29:53 -07:00
page_io.c mm: fix PageUptodate data race 2008-02-05 09:44:19 -08:00
page_isolation.c memory hotremove: unset migrate type "ISOLATE" after removal 2007-11-14 18:45:38 -08:00
page-writeback.c mm: Add NR_WRITEBACK_TEMP counter 2008-04-30 08:29:50 -07:00
pagewalk.c mm: fix possible off-by-one in walk_pte_range() 2008-04-28 08:58:16 -07:00
pdflush.c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/juhl/trivial 2008-04-21 16:36:46 -07:00
prio_tree.c spelling fixes: mm/ 2007-10-20 01:27:18 +02:00
quicklist.c quicklists: Only consider memory that can be used with GFP_KERNEL 2008-01-14 08:52:22 -08:00
readahead.c mm: bdi: export BDI attributes in sysfs 2008-04-30 08:29:49 -07:00
rmap.c mm: remove nopage 2008-04-28 08:58:18 -07:00
shmem_acl.c [PATCH] Fix typos in mm/shmem_acl.c 2006-10-11 11:14:23 -07:00
shmem.c mm: bdi: add separate writeback accounting capability 2008-04-30 08:29:50 -07:00
slab.c mm: remove remaining __FUNCTION__ occurrences 2008-04-30 08:29:53 -07:00
slob.c slob: fix bug - when slob allocates "struct kmem_cache", it does not force alignment. 2008-04-27 18:25:51 +03:00
slub.c slub: #ifdef simplification 2008-05-02 00:27:13 +03:00
sparse-vmemmap.c NULL noise: fs/*, mm/*, kernel/* 2008-03-30 14:18:41 -07:00
sparse.c revert "memory hotplug: allocate usemap on the section with pgdat" 2008-04-30 08:29:55 -07:00
swap_state.c mm: bdi: add separate writeback accounting capability 2008-04-30 08:29:50 -07:00
swap.c mm: rotate_reclaimable_page() cleanup 2008-04-28 08:58:20 -07:00
swapfile.c mm: use non-racy method for /proc/swaps creation 2008-04-29 08:06:20 -07:00
thrash.c Bug in mm/thrash.c function grab_swap_token() 2007-05-11 08:29:32 -07:00
tiny-shmem.c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6 2008-03-25 08:57:47 -07:00
truncate.c fix invalidate_inode_pages2_range() to not clear ret 2008-04-28 08:58:18 -07:00
util.c fix mm/util.c:krealloc() 2007-11-14 18:45:41 -08:00
vmalloc.c docbook: fix vmalloc missing parameter notation 2008-05-01 08:03:59 -07:00
vmscan.c mm: remove remaining __FUNCTION__ occurrences 2008-04-30 08:29:53 -07:00
vmstat.c mm: Add NR_WRITEBACK_TEMP counter 2008-04-30 08:29:50 -07:00