linux/arch/arm64/mm
Ard Biesheuvel 4fee9f364b arm64: mm: use correct mapping granularity under DEBUG_RODATA
When booting a 64k pages kernel that is built with CONFIG_DEBUG_RODATA
and resides at an offset that is not a multiple of 512 MB, the rounding
that occurs in __map_memblock() and fixup_executable() results in
incorrect regions being mapped.

The following snippet from /sys/kernel/debug/kernel_page_tables shows
how, when the kernel is loaded 2 MB above the base of DRAM at 0x40000000,
the first 2 MB of memory (which may be inaccessible from non-secure EL1
or just reserved by the firmware) is inadvertently mapped into the end of
the module region.

  ---[ Modules start ]---
  0xfffffdffffe00000-0xfffffe0000000000     2M RW NX ... UXN MEM/NORMAL
  ---[ Modules end ]---
  ---[ Kernel Mapping ]---
  0xfffffe0000000000-0xfffffe0000090000   576K RW NX ... UXN MEM/NORMAL
  0xfffffe0000090000-0xfffffe0000200000  1472K ro x  ... UXN MEM/NORMAL
  0xfffffe0000200000-0xfffffe0000800000     6M ro x  ... UXN MEM/NORMAL
  0xfffffe0000800000-0xfffffe0000810000    64K ro x  ... UXN MEM/NORMAL
  0xfffffe0000810000-0xfffffe0000a00000  1984K RW NX ... UXN MEM/NORMAL
  0xfffffe0000a00000-0xfffffe00ffe00000  4084M RW NX ... UXN MEM/NORMAL

The same issue is likely to occur on 16k pages kernels whose load
address is not a multiple of 32 MB (i.e., SECTION_SIZE). So round to
SWAPPER_BLOCK_SIZE instead of SECTION_SIZE.

Fixes: da141706ae ("arm64: add better page protections to arm64")
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Acked-by: Laura Abbott <labbott@redhat.com>
Cc: <stable@vger.kernel.org> # 4.0+
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2015-11-17 12:05:18 +00:00
..
cache.S arm64: use ENDPIPROC() to annotate position independent assembler routines 2015-10-12 16:19:45 +01:00
context.c arm64: mm: kill mm_cpumask usage 2015-10-07 11:56:29 +01:00
copypage.c arm64: export __cpu_{clear,copy}_user_page functions 2014-07-08 17:30:51 +01:00
dma-mapping.c arm64/dma-mapping: Fix sizes in __iommu_{alloc,free}_attrs 2015-11-16 10:05:35 +00:00
dump.c arm64: Make the kernel page dump utility aware of the CONT bit 2015-10-08 18:39:57 +01:00
extable.c arm64: MMU fault handling and page table management 2012-09-17 13:41:57 +01:00
fault.c arm64 updates for 4.4: 2015-11-04 14:47:13 -08:00
flush.c arm64: force CONFIG_SMP=y and remove redundant #ifdefs 2015-07-27 11:08:40 +01:00
hugetlbpage.c arm64: hugetlb: remove paragraph about writing to FSF 2015-07-27 11:08:40 +01:00
init.c arm64: Fix build with CONFIG_ZONE_DMA=n 2015-10-29 16:58:00 +00:00
ioremap.c arm64: add ioremap physical address information 2015-01-23 15:29:06 +00:00
kasan_init.c arm64: kasan: fix issues reported by sparse 2015-10-13 14:54:42 +01:00
Makefile arm64: add KASAN support 2015-10-12 17:46:36 +01:00
mm.h arm64: add better page protections to arm64 2015-01-22 14:54:29 +00:00
mmap.c mm: expose arch_mmap_rnd when available 2015-04-14 16:49:05 -07:00
mmu.c arm64: mm: use correct mapping granularity under DEBUG_RODATA 2015-11-17 12:05:18 +00:00
pageattr.c arm64/mm: use PAGE_ALIGNED instead of IS_ALIGNED 2015-10-28 18:36:32 +00:00
pgd.c arm64: move PGD_SIZE definition to pgalloc.h 2015-10-12 17:46:30 +01:00
proc-macros.S arm64: mm: increase VA range of identity map 2015-03-23 11:35:29 +00:00
proc.S arm64 updates for 4.4: 2015-11-04 14:47:13 -08:00