On Tue, Apr 03, 2018 at 12:09:05PM +0100, Mark Rutland wrote:
From: Will Deacon will.deacon@arm.com
commit 51a0048beb44 upstream.
The exception entry trampoline needs to be mapped at the same virtual address in both the trampoline page table (which maps nothing else) and also the kernel page table, so that we can swizzle TTBR1_EL1 on exceptions from and return to EL0.
This patch maps the trampoline at a fixed virtual address in the fixmap area of the kernel virtual address space, which allows the kernel proper to be randomized with respect to the trampoline when KASLR is enabled.
Reviewed-by: Mark Rutland mark.rutland@arm.com Tested-by: Laura Abbott labbott@redhat.com Tested-by: Shanker Donthineni shankerd@codeaurora.org Signed-off-by: Will Deacon will.deacon@arm.com Signed-off-by: Alex Shi alex.shi@linaro.org Reviewed-by: Mark Rutland mark.rutland@arm.com [v4.9 backport]
It has just been pointed out to me that I messed up the SoB chain here, and this should be:
Signed-off-by: Mark Rutland mark.rutland@arm.com [v4.9 backport]
Otherwise, the patch itself is fine. Sorry for the noise there -- I hope this can be fixed up when applying?
Thanks, Mark.