[PATCH] arm64: always enable DEBUG_RODATA and remove the Kconfig option

On Thu, Aug 25, 2016 at 05:23:23PM +0100, Mark Rutland wrote:

Follow the example set by x86 in commit 9ccaf77cf05915f5 ("x86/mm:
Always enable CONFIG_DEBUG_RODATA and remove the Kconfig option"), and
make these protections a fundamental security feature rather than an
opt-in. This also results in a minor code simplification.

For those rare cases when users wish to disable this protection (e.g.
for debugging), this can be done by passing 'rodata=off' on the command
line.

As DEBUG_RODATA_ALIGN is only intended to address a performance/memory
tradeoff, and does not affect correctness, this is left user-selectable.
DEBUG_MODULE_RONX is also left user-selectable until the core code
provides a boot-time option to disable the protection for debugging
use-cases.

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Cc: Ard Biesheuvel <redacted>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Kees Cook <redacted>
Cc: Laura Abbott <redacted>
Cc: Will Deacon <redacted>
---
 arch/arm64/Kconfig       |  3 +++
 arch/arm64/Kconfig.debug | 10 ----------
 arch/arm64/kernel/insn.c |  2 +-
 3 files changed, 4 insertions(+), 11 deletions(-)

This is a very popular patch.

Applied for 4.9. Perhaps it makes up for all the unpopular patches I've
applied in the past.

Will