Hi,
This patch has a bug, and I think i'm going to tweak patch 9 to drop the
tristate (and default to a bool that is not vulnerable) since I ended up
adding all those extra return checks to deal with the unresponsive
firmware case.
On 4/10/19 6:12 PM, Jeremy Linton wrote:
Arm64 machines should be displaying a human readable
vulnerability status to speculative execution attacks in
/sys/devices/system/cpu/vulnerabilities
This series enables that behavior by providing the expected
functions. Those functions expose the cpu errata and feature
states, as well as whether firmware is responding appropriately
to display the overall machine status. This means that in a
heterogeneous machine we will only claim the machine is mitigated
or safe if we are confident all booted cores are safe or
mitigated.
v6->v7: Invert ssb white/black list logic so that we only mark
cores in the whitelist not affected when the firmware
fails to respond. Removed reviewed/tested tags for
just patch 9 because of this.
v5->v6:
Invert meltdown logic to display that a core is safe rather
than mitigated if the mitigation has been enabled on
machines that are safe. This can happen when the
mitigation was forced on via command line or KASLR.
This means that in order to detect if kpti is enabled
other methods must be used (look at dmesg) when the
machine isn't itself susceptible to meltdown.
Trivial whitespace tweaks.
v4->v5:
Revert the changes to remove the CONFIG_EXPERT hidden
options, but leave the detection paths building
without #ifdef wrappers. Also remove the
CONFIG_GENERIC_CPU_VULNERABILITIES #ifdefs
as we are 'select'ing the option in the Kconfig.
This allows us to keep all three variations of
the CONFIG/enable/disable paths without a lot of
(CONFIG_X || CONFIG_Y) checks.
Various bits/pieces moved between the patches in an attempt
to keep similar features/changes together.
v3->v4:
Drop the patch which selectivly exports sysfs entries
Remove the CONFIG_EXPERT hidden options which allowed
the kernel to be built without the vulnerability
detection code.
Pick Marc Z's patches which invert the white/black
lists for spectrev2 and clean up the firmware
detection logic.
Document the existing kpti controls
Add a nospectre_v2 option to boot time disable the
mitigation
v2->v3:
Remove "Unknown" states, replace with further blacklists
and default vulnerable/not affected states.
Add the ability for an arch port to selectively export
sysfs vulnerabilities.
v1->v2:
Add "Unknown" state to ABI/testing docs.
Minor tweaks.
Jeremy Linton (6):
arm64: Provide a command line to disable spectre_v2 mitigation
arm64: add sysfs vulnerability show for meltdown
arm64: Always enable spectrev2 vulnerability detection
arm64: add sysfs vulnerability show for spectre v2
arm64: Always enable ssb vulnerability detection
arm64: add sysfs vulnerability show for speculative store bypass
Marc Zyngier (2):
arm64: Advertise mitigation of Spectre-v2, or lack thereof
arm64: Use firmware to detect CPUs that are not affected by Spectre-v2
Mian Yousaf Kaukab (2):
arm64: add sysfs vulnerability show for spectre v1
arm64: enable generic CPU vulnerabilites support
.../admin-guide/kernel-parameters.txt | 8 +-
arch/arm64/Kconfig | 1 +
arch/arm64/include/asm/cpufeature.h | 4 -
arch/arm64/kernel/cpu_errata.c | 257 +++++++++++++-----
arch/arm64/kernel/cpufeature.c | 58 +++-
5 files changed, 241 insertions(+), 87 deletions(-)
