diff options
| -rw-r--r-- | Documentation/admin-guide/kernel-parameters.txt | 5 | ||||
| -rw-r--r-- | arch/s390/kernel/nospec-branch.c | 9 |
2 files changed, 12 insertions, 2 deletions
diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt index 204161cee674..6fa7895885c9 100644 --- a/Documentation/admin-guide/kernel-parameters.txt +++ b/Documentation/admin-guide/kernel-parameters.txt @@ -2389,7 +2389,7 @@ http://repo.or.cz/w/linux-2.6/mini2440.git mitigations= - [X86,PPC] Control optional mitigations for CPU + [X86,PPC,S390] Control optional mitigations for CPU vulnerabilities. This is a set of curated, arch-independent options, each of which is an aggregation of existing arch-specific options. @@ -2400,7 +2400,8 @@ expose users to several CPU vulnerabilities. Equivalent to: nopti [X86,PPC] nospectre_v1 [PPC] - nospectre_v2 [X86,PPC] + nobp=0 [S390] + nospectre_v2 [X86,PPC,S390] spectre_v2_user=off [X86] spec_store_bypass_disable=off [X86,PPC] l1tf=off [X86] diff --git a/arch/s390/kernel/nospec-branch.c b/arch/s390/kernel/nospec-branch.c index d5eed651b5ab..83e597688562 100644 --- a/arch/s390/kernel/nospec-branch.c +++ b/arch/s390/kernel/nospec-branch.c @@ -1,6 +1,7 @@ // SPDX-License-Identifier: GPL-2.0 #include <linux/module.h> #include <linux/device.h> +#include <linux/cpu.h> #include <asm/facility.h> #include <asm/nospec-branch.h> @@ -55,8 +56,16 @@ static int __init nospectre_v2_setup_early(char *str) } early_param("nospectre_v2", nospectre_v2_setup_early); + void __init nospec_auto_detect(void) { + if (cpu_mitigations_off()) { + /* + * Disable expolines and disable nobp. + */ + if (IS_ENABLED(CC_USING_EXPOLINE)) + nospec_disable = 1; + __clear_facility(82, S390_lowcore.alt_stfle_fac_list); if (IS_ENABLED(CC_USING_EXPOLINE)) { /* * The kernel has been compiled with expolines. |