From: Laurent Dufour ldufour@linux.ibm.com
commit c18956e6e0b95f78dad2773ecc8c61a9e41f6405 upstream.
After LPM, when migrating from a system with security mitigation enabled to a system with mitigation disabled, the security flavor exposed in /proc is not correctly set back to 0.
Do not assume the value of the security flavor is set to 0 when entering init_cpu_char_feature_flags(), so when called after a LPM, the value is set correctly even if the mitigation are not turned off.
Fixes: 6ce56e1ac380 ("powerpc/pseries: export LPAR security flavor in lparcfg") Cc: stable@vger.kernel.org # v5.13+ Signed-off-by: Laurent Dufour ldufour@linux.ibm.com Signed-off-by: Michael Ellerman mpe@ellerman.id.au Link: https://lore.kernel.org/r/20210805152308.33988-1-ldufour@linux.ibm.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- arch/powerpc/platforms/pseries/setup.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-)
--- a/arch/powerpc/platforms/pseries/setup.c +++ b/arch/powerpc/platforms/pseries/setup.c @@ -539,9 +539,10 @@ static void init_cpu_char_feature_flags( * H_CPU_BEHAV_FAVOUR_SECURITY_H could be set only if * H_CPU_BEHAV_FAVOUR_SECURITY is. */ - if (!(result->behaviour & H_CPU_BEHAV_FAVOUR_SECURITY)) + if (!(result->behaviour & H_CPU_BEHAV_FAVOUR_SECURITY)) { security_ftr_clear(SEC_FTR_FAVOUR_SECURITY); - else if (result->behaviour & H_CPU_BEHAV_FAVOUR_SECURITY_H) + pseries_security_flavor = 0; + } else if (result->behaviour & H_CPU_BEHAV_FAVOUR_SECURITY_H) pseries_security_flavor = 1; else pseries_security_flavor = 2;