[PATCH v6 00/10] arm64: add system vulnerability sysfs entries

Jeremy Linton jeremy.linton at arm.com
Thu Mar 21 16:05:47 PDT 2019


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.

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                | 239 +++++++++++++-----
 arch/arm64/kernel/cpufeature.c                |  58 ++++-
 5 files changed, 223 insertions(+), 87 deletions(-)

-- 
2.20.1




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