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a7892f32cc
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Ian Campbell a7892f32cc arm: xen: foreign mapping PTEs are special. 
These mappings are in fact special and require special handling in privcmd,
which already exists. Failure to mark the PTE as special on arm64 causes all
sorts of bad PTE fun. e.g.

e.g.:

BUG: Bad page map in process xl  pte:e0004077b33f53 pmd:4079575003
page:ffffffbce1a2f328 count:1 mapcount:-1 mapping:          (null) index:0x0
page flags: 0x4000000000000014(referenced|dirty)
addr:0000007fb5259000 vm_flags:040644fa anon_vma:          (null) mapping:ffffffc03a6fda58 index:0
vma->vm_ops->fault: privcmd_fault+0x0/0x38
vma->vm_file->f_op->mmap: privcmd_mmap+0x0/0x2c
CPU: 0 PID: 2657 Comm: xl Not tainted 3.12.0+ #102
Call trace:
[<ffffffc0000880f8>] dump_backtrace+0x0/0x12c
[<ffffffc000088238>] show_stack+0x14/0x1c
[<ffffffc0004b67e0>] dump_stack+0x70/0x90
[<ffffffc000125690>] print_bad_pte+0x12c/0x1bc
[<ffffffc0001268f4>] unmap_single_vma+0x4cc/0x700
[<ffffffc0001273b4>] unmap_vmas+0x68/0xb4
[<ffffffc00012c050>] unmap_region+0xcc/0x1d4
[<ffffffc00012df20>] do_munmap+0x218/0x314
[<ffffffc00012e060>] vm_munmap+0x44/0x64
[<ffffffc00012ed78>] SyS_munmap+0x24/0x34

Where unmap_single_vma contains inlined -> unmap_page_range -> zap_pud_range
-> zap_pmd_range -> zap_pte_range -> print_bad_pte.

Or:

BUG: Bad page state in process xl  pfn:4077b4d
page:ffffffbce1a2f8d8 count:0 mapcount:-1 mapping:          (null) index:0x0
page flags: 0x4000000000000014(referenced|dirty)
Modules linked in:
CPU: 0 PID: 2657 Comm: xl Tainted: G    B        3.12.0+ #102
Call trace:
[<ffffffc0000880f8>] dump_backtrace+0x0/0x12c
[<ffffffc000088238>] show_stack+0x14/0x1c
[<ffffffc0004b67e0>] dump_stack+0x70/0x90
[<ffffffc00010f798>] bad_page+0xc4/0x110
[<ffffffc00010f8b4>] free_pages_prepare+0xd0/0xd8
[<ffffffc000110e94>] free_hot_cold_page+0x28/0x178
[<ffffffc000111460>] free_hot_cold_page_list+0x38/0x60
[<ffffffc000114cf0>] release_pages+0x190/0x1dc
[<ffffffc00012c0e0>] unmap_region+0x15c/0x1d4
[<ffffffc00012df20>] do_munmap+0x218/0x314
[<ffffffc00012e060>] vm_munmap+0x44/0x64
[<ffffffc00012ed78>] SyS_munmap+0x24/0x34

x86 already gets this correct. 32-bit arm gets away with this because there is
not PTE_SPECIAL bit in the PTE there and the vm_normal_page fallback path does
the right thing.

Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
2013-12-11 17:06:05 +00:00
..
alpha Remove GENERIC_HARDIRQ config option 2013-09-13 15:09:52 +02:00
arc ARC: Ignore ptrace SETREGSET request for synthetic register "stop_pc" 2013-10-12 12:00:36 +05:30
arm arm: xen: foreign mapping PTEs are special. 2013-12-11 17:06:05 +00:00
arm64 xen/arm64: do not call the swiotlb functions twice 2013-12-11 16:21:00 +00:00
avr32 avr32: cast syscall_return to silence compiler warning 2013-09-30 08:42:01 +02:00
blackfin Merge branch 'genirq' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux 2013-09-13 07:31:38 -07:00
c6x Remove GENERIC_HARDIRQ config option 2013-09-13 15:09:52 +02:00
cris Remove GENERIC_HARDIRQ config option 2013-09-13 15:09:52 +02:00
frv Remove GENERIC_HARDIRQ config option 2013-09-13 15:09:52 +02:00
h8300 Remove GENERIC_HARDIRQ config option 2013-09-13 15:09:52 +02:00
hexagon Remove GENERIC_HARDIRQ config option 2013-09-13 15:09:52 +02:00
ia64 xen: introduce xen_dma_map/unmap_page and xen_dma_sync_single_for_cpu/device 2013-10-25 10:39:49 +00:00
m32r Remove GENERIC_HARDIRQ config option 2013-09-13 15:09:52 +02:00
m68k Remove GENERIC_HARDIRQ config option 2013-09-13 15:09:52 +02:00
metag Remove GENERIC_HARDIRQ config option 2013-09-13 15:09:52 +02:00
microblaze Remove GENERIC_HARDIRQ config option 2013-09-13 15:09:52 +02:00
mips Merge branch 'core-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2013-10-12 11:06:18 -07:00
mn10300 Remove GENERIC_HARDIRQ config option 2013-09-13 15:09:52 +02:00
openrisc openrisc: clean-up prom.h 2013-09-24 21:12:27 -05:00
parisc parisc: let probe_kernel_read() capture access to page zero 2013-10-13 17:46:31 +02:00
powerpc compiler/gcc4: Add quirk for 'asm goto' miscompilation bug 2013-10-11 07:39:14 +02:00
s390 compiler/gcc4: Add quirk for 'asm goto' miscompilation bug 2013-10-11 07:39:14 +02:00
score Score: Modify the Makefile of Score, remove -mlong-calls for compiling 2013-09-26 03:46:03 +08:00
sh Remove GENERIC_HARDIRQ config option 2013-09-13 15:09:52 +02:00
sparc compiler/gcc4: Add quirk for 'asm goto' miscompilation bug 2013-10-11 07:39:14 +02:00
tile arch: tile: re-use kbasename() helper 2013-09-30 10:34:46 -04:00
um Remove GENERIC_HARDIRQ config option 2013-09-13 15:09:52 +02:00
unicore32 Remove GENERIC_HARDIRQ config option 2013-09-13 15:09:52 +02:00
x86 Merge remote-tracking branch 'stefano/swiotlb-xen-9.1' into stable/for-linus-3.13 2013-11-08 16:10:48 -05:00
xtensa Xtensa patchset for v3.12 2013-09-13 10:57:48 -07:00
.gitignore
Kconfig mutex: replace CONFIG_HAVE_ARCH_MUTEX_CPU_RELAX with simple ifdef 2013-09-28 12:46:21 +02:00