diff options
| author | Russell King <rmk+kernel@arm.linux.org.uk> | 2013-07-04 10:40:32 (GMT) |
|---|---|---|
| committer | Russell King <rmk+kernel@arm.linux.org.uk> | 2013-07-31 20:31:36 (GMT) |
| commit | 19accfd373847ac3d10623c5d20f948846299741 (patch) | |
| tree | 682dd44ea1710afbb7e61a24185ffa4c9a0fb0da /arch/arm/mm/mmu.c | |
| parent | 5b43e7a383d69381ffe53423e46dd0fafae07da3 (diff) | |
| download | linux-19accfd373847ac3d10623c5d20f948846299741.tar.xz | |
ARM: move vector stubs
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.
Cc: <stable@vger.kernel.org>
Acked-by: Nicolas Pitre <nico@linaro.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Diffstat (limited to 'arch/arm/mm/mmu.c')
| -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 4f56617..9ea274d 100644 --- a/arch/arm/mm/mmu.c +++ b/arch/arm/mm/mmu.c @@ -1160,7 +1160,7 @@ 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); @@ -1210,10 +1210,18 @@ 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. */ |