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| author | Russell King <rmk+kernel@arm.linux.org.uk> | 2013-07-04 11:40:32 +0100 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2013-08-11 18:35:20 -0700 |
| commit | b85796fa1987e014a61c379e3cb753976e993a46 (patch) | |
| tree | f80f85350b34fe91c2b67b31e86e497e4bf16b3f /arch/arm/mm | |
| parent | ddc8d5e58a818e543ac658a572b3155c8ea3e45d (diff) | |
| download | linux-3.10-b85796fa1987e014a61c379e3cb753976e993a46.tar.gz linux-3.10-b85796fa1987e014a61c379e3cb753976e993a46.tar.bz2 linux-3.10-b85796fa1987e014a61c379e3cb753976e993a46.zip | |
ARM: move vector stubs
commit 19accfd373847ac3d10623c5d20f948846299741 upstream.
Move the machine vector stubs into the page above the vector page,
which we can prevent from being visible to userspace. Also move
the reset stub, and place the swi vector at a location that the
'ldr' can get to it.
This hides pointers into the kernel which could give valuable
information to attackers, and reduces the number of exploitable
instructions at a fixed address.
Acked-by: Nicolas Pitre <nico@linaro.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'arch/arm/mm')
| -rw-r--r-- | arch/arm/mm/mmu.c | 10 |
1 files changed, 9 insertions, 1 deletions
diff --git a/arch/arm/mm/mmu.c b/arch/arm/mm/mmu.c index 4d409e6a552..08b37c421a5 100644 --- a/arch/arm/mm/mmu.c +++ b/arch/arm/mm/mmu.c @@ -1175,7 +1175,7 @@ static void __init devicemaps_init(struct machine_desc *mdesc) /* * Allocate the vector page early. */ - vectors = early_alloc(PAGE_SIZE); + vectors = early_alloc(PAGE_SIZE * 2); early_trap_init(vectors); @@ -1225,10 +1225,18 @@ static void __init devicemaps_init(struct machine_desc *mdesc) if (!vectors_high()) { map.virtual = 0; + map.length = PAGE_SIZE * 2; map.type = MT_LOW_VECTORS; create_mapping(&map); } + /* Now create a kernel read-only mapping */ + map.pfn += 1; + map.virtual = 0xffff0000 + PAGE_SIZE; + map.length = PAGE_SIZE; + map.type = MT_LOW_VECTORS; + create_mapping(&map); + /* * Ask the machine support to map in the statically mapped devices. */ |