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Catalin Marinas 623e5ae074 arm64: Revert support for execute-only user mappings 
commit 24cecc3774 upstream.

The ARMv8 64-bit architecture supports execute-only user permissions by
clearing the PTE_USER and PTE_UXN bits, practically making it a mostly
privileged mapping but from which user running at EL0 can still execute.

The downside, however, is that the kernel at EL1 inadvertently reading
such mapping would not trip over the PAN (privileged access never)
protection.

Revert the relevant bits from commit cab15ce604 ("arm64: Introduce
execute-only page access permissions") so that PROT_EXEC implies
PROT_READ (and therefore PTE_USER) until the architecture gains proper
support for execute-only user mappings.

Fixes: cab15ce604 ("arm64: Introduce execute-only page access permissions")
Cc: <stable@vger.kernel.org> # 4.9.x-
Acked-by: Will Deacon <will@kernel.org>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
 		2020-01-09 10:20:01 +01:00
..
Makefile
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cache.S
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context.c
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copypage.c
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dma-mapping.c
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dump.c
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extable.c
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fault.c arm64: Revert support for execute-only user mappings 2020-01-09 10:20:01 +01:00
flush.c mm: introduce page_size() 2019-09-24 15:54:08 -07:00
hugetlbpage.c
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init.c
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ioremap.c
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kasan_init.c
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mmap.c arm64, mm: move generic mmap layout functions to mm 2019-09-24 15:54:11 -07:00
mmu.c mm/memory_hotplug: shrink zones when offlining memory 2020-01-09 10:19:56 +01:00
numa.c
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pageattr.c
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pgd.c mm: consolidate pgtable_cache_init() and pgd_cache_init() 2019-09-24 15:54:09 -07:00
physaddr.c
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proc.S
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ptdump_debugfs.c
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