[PATCH] powerpc/pseries: Fix update of LPAR security flavor after LPM

From: Laurent Dufour
Date: Thu Aug 05 2021 - 11:25:48 EST


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@xxxxxxxxxxxxxxx # 5.13.x
Signed-off-by: Laurent Dufour <ldufour@xxxxxxxxxxxxx>
---
arch/powerpc/platforms/pseries/setup.c | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/arch/powerpc/platforms/pseries/setup.c b/arch/powerpc/platforms/pseries/setup.c
index 6b0886668465..0dfaa6ab44cc 100644
--- 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(struct h_cpu_char_result *result)
* 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;
--
2.32.0