linux/arch/arm/mm
Will Deacon 7b7bf499f7 ARM: 6913/1: sparsemem: allow pfn_valid to be overridden when using SPARSEMEM
In commit eb33575c ("[ARM] Double check memmap is actually valid with a
memmap has unexpected holes V2"), a new function, memmap_valid_within,
was introduced to mmzone.h so that holes in the memmap which pass
pfn_valid in SPARSEMEM configurations can be detected and avoided.

The fix to this problem checks that the pfn <-> page linkages are
correct by calculating the page for the pfn and then checking that
page_to_pfn on that page returns the original pfn. Unfortunately, in
SPARSEMEM configurations, this results in reading from the page flags to
determine the correct section. Since the memmap here has been freed,
junk is read from memory and the check is no longer robust.

In the best case, reading from /proc/pagetypeinfo will give you the
wrong answer. In the worst case, you get SEGVs, Kernel OOPses and hung
CPUs. Furthermore, ioremap implementations that use pfn_valid to
disallow the remapping of normal memory will break.

This patch allows architectures to provide their own pfn_valid function
instead of using the default implementation used by sparsemem. The
architecture-specific version is aware of the memmap state and will
return false when passed a pfn for a freed page within a valid section.

Acked-by: Mel Gorman <mgorman@suse.de>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Tested-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2011-05-26 10:23:24 +01:00
..
abort-ev4.S
abort-ev4t.S
abort-ev5t.S
abort-ev5tj.S
abort-ev6.S ARM: v6k: select clear exclusive code seqences according to V6 variants 2011-02-02 21:23:28 +00:00
abort-ev7.S arm: mm: qsd8x50: Fix incorrect permission faults 2010-05-03 11:15:05 -07:00
abort-lv4t.S
abort-macro.S
abort-nommu.S
alignment.c ARM: 6401/1: plug a race in the alignment trap handler 2010-09-23 15:17:04 +01:00
cache-fa.S ARM: 6466/1: implement flush_icache_all for the rest of the CPUs 2010-10-28 13:54:28 +01:00
cache-feroceon-l2.c ARM: fix cache-feroceon-l2 after stack based kmap_atomic() 2010-12-19 12:57:16 -05:00
cache-l2x0.c Merge branch 'misc' into devel 2011-03-16 23:35:25 +00:00
cache-tauros2.c ARM: Add Tauros2 L2 cache controller support 2009-11-27 15:43:21 -05:00
cache-v3.S ARM: 6466/1: implement flush_icache_all for the rest of the CPUs 2010-10-28 13:54:28 +01:00
cache-v4.S ARM: 6466/1: implement flush_icache_all for the rest of the CPUs 2010-10-28 13:54:28 +01:00
cache-v4wb.S Fix common misspellings 2011-03-31 11:26:23 -03:00
cache-v4wt.S Fix common misspellings 2011-03-31 11:26:23 -03:00
cache-v6.S ARM: 6535/1: V6 MPCore v6_dma_inv_range and v6_dma_flush_range RWFO fix 2010-12-14 22:23:34 +00:00
cache-v7.S Fix common misspellings 2011-03-31 11:26:23 -03:00
cache-xsc3l2.c ARM: fix cache-xsc3l2 after stack based kmap_atomic() 2010-12-19 12:57:08 -05:00
context.c ARM: 5905/1: ARM: Global ASID allocation on SMP 2010-02-15 21:39:51 +00:00
copypage-fa.c ARM: Gemini: fix compiler error in copypage-fa.c 2010-04-27 12:45:10 +02:00
copypage-feroceon.c ARM: 6164/1: Add kto and kfrom to input operands list. 2010-06-08 19:42:18 +01:00
copypage-v3.c ARM: Pass VMA to copy_user_highpage() implementations 2009-10-05 15:17:45 +01:00
copypage-v4mc.c ARM: 6379/1: Assume new page cache pages have dirty D-cache 2010-09-19 12:17:43 +01:00
copypage-v4wb.c ARM: 6164/1: Add kto and kfrom to input operands list. 2010-06-08 19:42:18 +01:00
copypage-v4wt.c ARM: 6164/1: Add kto and kfrom to input operands list. 2010-06-08 19:42:18 +01:00
copypage-v6.c ARM: 6379/1: Assume new page cache pages have dirty D-cache 2010-09-19 12:17:43 +01:00
copypage-xsc3.c ARM: 6164/1: Add kto and kfrom to input operands list. 2010-06-08 19:42:18 +01:00
copypage-xscale.c ARM: 6379/1: Assume new page cache pages have dirty D-cache 2010-09-19 12:17:43 +01:00
dma-mapping.c Merge branches 'fixes', 'pgt-next' and 'versatile' into devel 2011-03-20 09:32:12 +00:00
extable.c
fault-armv.c ARM: pgtable: add pud-level code 2011-02-21 19:24:14 +00:00
fault.c ARM: pgtable: add pud-level code 2011-02-21 19:24:14 +00:00
fault.h
flush.c Merge branches 'consolidate', 'ep93xx', 'fixes', 'misc', 'mmci', 'remove' and 'spear' into for-linus 2011-05-23 19:27:40 +01:00
highmem.c ARM: get rid of kmap_high_l1_vipt() 2010-12-19 12:56:46 -05:00
idmap.c ARM: pgtable: add pud-level code 2011-02-21 19:24:14 +00:00
init.c ARM: 6913/1: sparsemem: allow pfn_valid to be overridden when using SPARSEMEM 2011-05-26 10:23:24 +01:00
iomap.c
ioremap.c Revert "ARM: relax ioremap prohibition (309caa9) for -final and -stable" 2010-12-24 09:49:52 +00:00
Kconfig Merge branch 'devel-stable' of master.kernel.org:/home/rmk/linux-2.6-arm 2011-03-17 19:08:06 -07:00
Makefile ARM: v6k: introduce CPU_V6K option 2011-02-02 21:23:26 +00:00
mm.h ARM: pgtable: add pud-level code 2011-02-21 19:24:14 +00:00
mmap.c ARM: 6877/1: the ADDR_NO_RANDOMIZE personality flag should be honored with mmap() 2011-04-14 09:15:24 +01:00
mmu.c mm: now that all old mmu_gather code is gone, remove the storage 2011-05-25 08:39:16 -07:00
nommu.c ARM: Convert platform reservations to use LMB rather than bootmem 2010-07-27 08:48:23 +01:00
pabort-legacy.S ARM: 5727/1: Pass IFSR register to do_PrefetchAbort() 2009-10-02 22:34:32 +01:00
pabort-v6.S ARM: 5727/1: Pass IFSR register to do_PrefetchAbort() 2009-10-02 22:34:32 +01:00
pabort-v7.S ARM: 5727/1: Pass IFSR register to do_PrefetchAbort() 2009-10-02 22:34:32 +01:00
pgd.c Merge branches 'fixes', 'pgt-next' and 'versatile' into devel 2011-03-20 09:32:12 +00:00
proc-arm6_7.S ARM: pm: add generic CPU suspend/resume support 2011-02-22 17:11:23 +00:00
proc-arm7tdmi.S ARM: pm: add generic CPU suspend/resume support 2011-02-22 17:11:23 +00:00
proc-arm9tdmi.S ARM: pm: add generic CPU suspend/resume support 2011-02-22 17:11:23 +00:00
proc-arm720.S Fix common misspellings 2011-03-31 11:26:23 -03:00
proc-arm740.S ARM: pm: add generic CPU suspend/resume support 2011-02-22 17:11:23 +00:00
proc-arm920.S Merge branch 'fix' of git://git.kernel.org/pub/scm/linux/kernel/git/ycmiao/pxa-linux-2.6 into fixes 2011-04-13 23:32:13 +01:00
proc-arm922.S Fix common misspellings 2011-03-31 11:26:23 -03:00
proc-arm925.S Fix common misspellings 2011-03-31 11:26:23 -03:00
proc-arm926.S ARM: Make consolidated PM sleep code depend on PM_SLEEP 2011-04-02 10:08:55 +01:00
proc-arm940.S ARM: pm: add generic CPU suspend/resume support 2011-02-22 17:11:23 +00:00
proc-arm946.S ARM: pm: add generic CPU suspend/resume support 2011-02-22 17:11:23 +00:00
proc-arm1020.S Fix common misspellings 2011-03-31 11:26:23 -03:00
proc-arm1020e.S Fix common misspellings 2011-03-31 11:26:23 -03:00
proc-arm1022.S Fix common misspellings 2011-03-31 11:26:23 -03:00
proc-arm1026.S Fix common misspellings 2011-03-31 11:26:23 -03:00
proc-fa526.S ARM: pm: add generic CPU suspend/resume support 2011-02-22 17:11:23 +00:00
proc-feroceon.S ARM: pm: add generic CPU suspend/resume support 2011-02-22 17:11:23 +00:00
proc-macros.S Fix common misspellings 2011-03-31 11:26:23 -03:00
proc-mohawk.S ARM: pm: add generic CPU suspend/resume support 2011-02-22 17:11:23 +00:00
proc-sa110.S ARM: pm: add generic CPU suspend/resume support 2011-02-22 17:11:23 +00:00
proc-sa1100.S ARM: Make consolidated PM sleep code depend on PM_SLEEP 2011-04-02 10:08:55 +01:00
proc-syms.c ARM: add size argument to __cpuc_flush_dcache_page 2009-12-14 14:53:22 +00:00
proc-v6.S ARM: PJ4: remove the ARMv6 compatible cache method entries 2011-05-03 15:39:05 -04:00
proc-v7.S Merge branch 'fix' of git://git.kernel.org/pub/scm/linux/kernel/git/ycmiao/pxa-linux-2.6 into fixes 2011-04-13 23:32:13 +01:00
proc-xsc3.S ARM: Make consolidated PM sleep code depend on PM_SLEEP 2011-04-02 10:08:55 +01:00
proc-xscale.S ARM: Fix .size directive for xscale_dma_a0_map_area 2011-04-28 17:56:31 +08:00
tlb-fa.S
tlb-v3.S
tlb-v4.S
tlb-v4wb.S
tlb-v4wbi.S
tlb-v6.S
tlb-v7.S ARM: Allow SMP kernels to boot on UP systems 2010-10-04 20:23:36 +01:00
vmregion.c ARM: DMA: top-down allocation in DMA coherent region 2011-02-23 17:24:11 +00:00
vmregion.h ARM: DMA coherent allocator: align remapped addresses 2010-07-27 10:43:48 +01:00