[v12,0/2] ARMv8.5-RNG support

Message

Mark Brown Jan. 20, 2020, 1:46 p.m. UTC

This series is based on Richard Henderson's previous v7, it addresses
review comments from that version by dropping the boot time RNG
support and adds a new change that uses the v8.5-RNG extension to
seed KASLR when ARCH_RANDOM is enabled.  The boot time support
will be re-added later, there are awkward potential interactons
with CPU feature enumeration which need a bit more thought.

v12:
 - Move definition of __early_cpu_has_rndr() into KASLR patch.
v11:
 - Add a hwcap for v8.5-RNG.
 - Drop the addition of data to the pool, it's of questionable
   value and we need to go back and get the addition of actual
   entropy working anyway.
v10:
 - Spell out that we're adding data not entropy from setup_arch() in
   the commit message for patch 2.
v9:
 - Make another static inline helper for early feature checks.
 - Add init annotations.
 - Use xor to add RNDR output to seed for KASLR.

Mark Brown (1):
  arm64: Use v8.5-RNG entropy for KASLR seed

Richard Henderson (1):
  arm64: Implement archrandom.h for ARMv8.5-RNG

 Documentation/arm64/cpu-feature-registers.rst |  2 +
 arch/arm64/Kconfig                            | 12 +++
 arch/arm64/include/asm/archrandom.h           | 75 +++++++++++++++++++
 arch/arm64/include/asm/cpucaps.h              |  3 +-
 arch/arm64/include/asm/sysreg.h               |  4 +
 arch/arm64/kernel/cpufeature.c                | 13 ++++
 arch/arm64/kernel/kaslr.c                     | 11 +++
 7 files changed, 119 insertions(+), 1 deletion(-)
 create mode 100644 arch/arm64/include/asm/archrandom.h

Comments

Will Deacon Jan. 21, 2020, 11:57 a.m. UTC | #1

On Mon, Jan 20, 2020 at 01:46:19PM +0000, Mark Brown wrote:
> This series is based on Richard Henderson's previous v7, it addresses
> review comments from that version by dropping the boot time RNG
> support and adds a new change that uses the v8.5-RNG extension to
> seed KASLR when ARCH_RANDOM is enabled.  The boot time support
> will be re-added later, there are awkward potential interactons
> with CPU feature enumeration which need a bit more thought.
> 
> v12:
>  - Move definition of __early_cpu_has_rndr() into KASLR patch.

Hmm, the HWCAP also seems to have disappeared in this version :/

Will

Mark Brown Jan. 21, 2020, 12:10 p.m. UTC | #2

On Tue, Jan 21, 2020 at 11:57:13AM +0000, Will Deacon wrote:
> On Mon, Jan 20, 2020 at 01:46:19PM +0000, Mark Brown wrote:

> > This series is based on Richard Henderson's previous v7, it addresses
> > review comments from that version by dropping the boot time RNG

> Hmm, the HWCAP also seems to have disappeared in this version :/

Oh, sorry :(  I was travelling last week and apparently messed up moving
this from my laptop back to my desktop before sending this out.  Let's
try again...