Xmon should be either fully or partially disabled depending on the kernel lockdown state.
Put xmon into read-only mode for lockdown=integrity and completely disable xmon when lockdown=confidentiality. Since this can occur dynamically, there may be pre-existing, active breakpoints in xmon when transitioning into read-only mode. These breakpoints will still trigger, so allow them to be listed, but not cleared or altered, using xmon. Changes since v3: - Allow active breakpoints to be shown/listed in read-only mode Changes since v2: - Rebased onto v36 of https://patchwork.kernel.org/cover/11049461/ (based on: f632a8170a6b667ee4e3f552087588f0fe13c4bb) - Do not clear existing breakpoints when transitioning from lockdown=none to lockdown=integrity - Remove line continuation and dangling quote (confuses checkpatch.pl) from the xmon command help/usage string Christopher M. Riedl (2): powerpc/xmon: Allow listing active breakpoints in read-only mode powerpc/xmon: Restrict when kernel is locked down arch/powerpc/xmon/xmon.c | 78 ++++++++++++++++++++++++++++++++---- include/linux/security.h | 2 + security/lockdown/lockdown.c | 2 + 3 files changed, 74 insertions(+), 8 deletions(-) -- 2.22.0