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 # 5.13.x Signed-off-by: Laurent Dufour ldufour@linux.ibm.com --- 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;
On Thu, 5 Aug 2021 17:23:08 +0200, Laurent Dufour wrote:
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.
[...]
Applied to powerpc/fixes.
[1/1] powerpc/pseries: Fix update of LPAR security flavor after LPM https://git.kernel.org/powerpc/c/c18956e6e0b95f78dad2773ecc8c61a9e41f6405
cheers
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