Add page protections for arm64 similar to those in arm.
This is for security reasons to prevent certain classes
of exploits. The current method:
- Map all memory as either RWX or RW. We round to the nearest
section to avoid creating page tables before everything is mapped
- Once everything is mapped, if either end of the RWX section should
not be X, we split the PMD and remap as necessary
- When initmem is to be freed, we change the permissions back to
RW (using stop machine if necessary to flush the TLB)
- If CONFIG_DEBUG_RODATA is set, the read only sections are set
read only.
Acked-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Tested-by: Kees Cook <keescook@chromium.org>
Tested-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Laura Abbott <lauraa@codeaurora.org>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
The commit 3690951fc6
(arm64: Use swiotlb late initialisation)
switches the DMA mapping code to swiotlb_tlb_late_init_with_default_size(),
the arm64_swiotlb_init() will not used anymore, so remove this function.
Signed-off-by: Ding Tianhong <dingtianhong@huawei.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
This function is only used in __sync_icache_dcache(), so remove it and
call __flush_dcache_area() directly. The flush_icache_user_range()
function is not used in the arm64 kernel.
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Reported-by: Will Deacon <will.deacon@arm.com>
Acked-by: Will Deacon <will.deacon@arm.com>
Following commit 74838b7 (swiotlb: add the late swiotlb initialization
function with iotlb memory) the swiotlb_init_with_default_size() is a
static function. This patch changes the arm64 code to call
swiotlb_init() instead and use the default size of 64MB. It is assumed
that AArch64 platforms have enough RAM to afford the pre-allocated
swiotlb memory. It also removes the #ifdef around this call since
CONFIG_SWIOTLB is always enabled.
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
This patch adds support for the handling of the MMU faults (exception
entry code introduced by a previous patch) and page table management.
The user translation table is pointed to by TTBR0 and the kernel one
(swapper_pg_dir) by TTBR1. There is no translation information shared or
address space overlapping between user and kernel page tables.
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: Tony Lindgren <tony@atomide.com>
Acked-by: Nicolas Pitre <nico@linaro.org>
Acked-by: Olof Johansson <olof@lixom.net>
Acked-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Laura Abbott