Commits
![Christopher M. Riedl](https://secure.gravatar.com/avatar/d9aed4c1c1fafeda8f90ac7f97c9859b.jpg?s=96&d=mm)
Christopher M. Riedl committed 99c63ba21d2
powerpc/xmon: Restrict when kernel is locked down [ Upstream commit 69393cb03ccdf29f3b452d3482ef918469d1c098 ] Xmon should be either fully or partially disabled depending on the kernel lockdown state. Put xmon into read-only mode for lockdown=integrity and prevent user entry into xmon when lockdown=confidentiality. Xmon checks the lockdown state on every attempted entry: (1) during early xmon'ing (2) when triggered via sysrq (3) when toggled via debugfs (4) when triggered via a previously enabled breakpoint The following lockdown state transitions are handled: (1) lockdown=none -> lockdown=integrity set xmon read-only mode (2) lockdown=none -> lockdown=confidentiality clear all breakpoints, set xmon read-only mode, prevent user re-entry into xmon (3) lockdown=integrity -> lockdown=confidentiality clear all breakpoints, set xmon read-only mode, prevent user re-entry into xmon Suggested-by: Andrew Donnellan <ajd@linux.ibm.com> Signed-off-by: Christopher M. Riedl <cmr@informatik.wtf> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20190907061124.1947-3-cmr@informatik.wtf Signed-off-by: Sasha Levin <sashal@kernel.org>