Commit-ID: 782e69efb3dfed6e8360bc612e8c7827a901a8f9 Gitweb: https://git.kernel.org/tip/782e69efb3dfed6e8360bc612e8c7827a901a8f9 Author: Josh Poimboeuf <jpoimboe@xxxxxxxxxx> AuthorDate: Fri, 12 Apr 2019 15:39:30 -0500 Committer: Thomas Gleixner <tglx@xxxxxxxxxxxxx> CommitDate: Wed, 17 Apr 2019 21:37:29 +0200 powerpc/speculation: Support 'mitigations=' cmdline option Configure powerpc CPU runtime speculation bug mitigations in accordance with the 'mitigations=' cmdline option. This affects Meltdown, Spectre v1, Spectre v2, and Speculative Store Bypass. The default behavior is unchanged. Signed-off-by: Josh Poimboeuf <jpoimboe@xxxxxxxxxx> Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx> Tested-by: Jiri Kosina <jkosina@xxxxxxx> (on x86) Reviewed-by: Jiri Kosina <jkosina@xxxxxxx> Cc: Borislav Petkov <bp@xxxxxxxxx> Cc: "H . Peter Anvin" <hpa@xxxxxxxxx> Cc: Andy Lutomirski <luto@xxxxxxxxxx> Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx> Cc: Jiri Kosina <jikos@xxxxxxxxxx> Cc: Waiman Long <longman@xxxxxxxxxx> Cc: Andrea Arcangeli <aarcange@xxxxxxxxxx> Cc: Jon Masters <jcm@xxxxxxxxxx> Cc: Benjamin Herrenschmidt <benh@xxxxxxxxxxxxxxxxxxx> Cc: Paul Mackerras <paulus@xxxxxxxxx> Cc: Michael Ellerman <mpe@xxxxxxxxxxxxxx> Cc: linuxppc-dev@xxxxxxxxxxxxxxxx Cc: Martin Schwidefsky <schwidefsky@xxxxxxxxxx> Cc: Heiko Carstens <heiko.carstens@xxxxxxxxxx> Cc: linux-s390@xxxxxxxxxxxxxxx Cc: Catalin Marinas <catalin.marinas@xxxxxxx> Cc: Will Deacon <will.deacon@xxxxxxx> Cc: linux-arm-kernel@xxxxxxxxxxxxxxxxxxx Cc: linux-arch@xxxxxxxxxxxxxxx Cc: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> Cc: Tyler Hicks <tyhicks@xxxxxxxxxxxxx> Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx> Cc: Randy Dunlap <rdunlap@xxxxxxxxxxxxx> Cc: Steven Price <steven.price@xxxxxxx> Cc: Phil Auld <pauld@xxxxxxxxxx> Link: https://lkml.kernel.org/r/245a606e1a42a558a310220312d9b6adb9159df6.1555085500.git.jpoimboe@xxxxxxxxxx --- Documentation/admin-guide/kernel-parameters.txt | 9 +++++---- arch/powerpc/kernel/security.c | 6 +++--- arch/powerpc/kernel/setup_64.c | 2 +- 3 files changed, 9 insertions(+), 8 deletions(-) diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt index 779ddeb2929c..ac7150a25a7a 100644 --- a/Documentation/admin-guide/kernel-parameters.txt +++ b/Documentation/admin-guide/kernel-parameters.txt @@ -2514,7 +2514,7 @@ http://repo.or.cz/w/linux-2.6/mini2440.git mitigations= - [X86] Control optional mitigations for CPU + [X86,PPC] 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. @@ -2523,10 +2523,11 @@ Disable all optional CPU mitigations. This improves system performance, but it may also expose users to several CPU vulnerabilities. - Equivalent to: nopti [X86] - nospectre_v2 [X86] + Equivalent to: nopti [X86,PPC] + nospectre_v1 [PPC] + nospectre_v2 [X86,PPC] spectre_v2_user=off [X86] - spec_store_bypass_disable=off [X86] + spec_store_bypass_disable=off [X86,PPC] l1tf=off [X86] auto (default) diff --git a/arch/powerpc/kernel/security.c b/arch/powerpc/kernel/security.c index 9b8631533e02..cdf3e73000e9 100644 --- a/arch/powerpc/kernel/security.c +++ b/arch/powerpc/kernel/security.c @@ -57,7 +57,7 @@ void setup_barrier_nospec(void) enable = security_ftr_enabled(SEC_FTR_FAVOUR_SECURITY) && security_ftr_enabled(SEC_FTR_BNDS_CHK_SPEC_BAR); - if (!no_nospec) + if (!no_nospec && !cpu_mitigations_off()) enable_barrier_nospec(enable); } @@ -116,7 +116,7 @@ static int __init handle_nospectre_v2(char *p) early_param("nospectre_v2", handle_nospectre_v2); void setup_spectre_v2(void) { - if (no_spectrev2) + if (no_spectrev2 || cpu_mitigations_off()) do_btb_flush_fixups(); else btb_flush_enabled = true; @@ -307,7 +307,7 @@ void setup_stf_barrier(void) stf_enabled_flush_types = type; - if (!no_stf_barrier) + if (!no_stf_barrier && !cpu_mitigations_off()) stf_barrier_enable(enable); } diff --git a/arch/powerpc/kernel/setup_64.c b/arch/powerpc/kernel/setup_64.c index 236c1151a3a7..c7ec27ba8926 100644 --- a/arch/powerpc/kernel/setup_64.c +++ b/arch/powerpc/kernel/setup_64.c @@ -958,7 +958,7 @@ void setup_rfi_flush(enum l1d_flush_type types, bool enable) enabled_flush_types = types; - if (!no_rfi_flush) + if (!no_rfi_flush && !cpu_mitigations_off()) rfi_flush_enable(enable); }
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