| From 1caa66c02b21ad771c6bfa38327c68ba308a633d Mon Sep 17 00:00:00 2001 |
| From: Josh Poimboeuf <jpoimboe@redhat.com> |
| Date: Fri, 12 Apr 2019 15:39:30 -0500 |
| Subject: [PATCH 25/30] powerpc/speculation: Support 'mitigations=' cmdline |
| option |
| |
| commit 782e69efb3dfed6e8360bc612e8c7827a901a8f9 upstream |
| |
| 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@redhat.com> |
| Signed-off-by: Thomas Gleixner <tglx@linutronix.de> |
| Tested-by: Jiri Kosina <jkosina@suse.cz> (on x86) |
| Reviewed-by: Jiri Kosina <jkosina@suse.cz> |
| Cc: Borislav Petkov <bp@alien8.de> |
| Cc: "H . Peter Anvin" <hpa@zytor.com> |
| Cc: Andy Lutomirski <luto@kernel.org> |
| Cc: Peter Zijlstra <peterz@infradead.org> |
| Cc: Jiri Kosina <jikos@kernel.org> |
| Cc: Waiman Long <longman@redhat.com> |
| Cc: Andrea Arcangeli <aarcange@redhat.com> |
| Cc: Jon Masters <jcm@redhat.com> |
| Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> |
| Cc: Paul Mackerras <paulus@samba.org> |
| Cc: Michael Ellerman <mpe@ellerman.id.au> |
| Cc: linuxppc-dev@lists.ozlabs.org |
| Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> |
| Cc: Heiko Carstens <heiko.carstens@de.ibm.com> |
| Cc: linux-s390@vger.kernel.org |
| Cc: Catalin Marinas <catalin.marinas@arm.com> |
| Cc: Will Deacon <will.deacon@arm.com> |
| Cc: linux-arm-kernel@lists.infradead.org |
| Cc: linux-arch@vger.kernel.org |
| Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
| Cc: Tyler Hicks <tyhicks@canonical.com> |
| Cc: Linus Torvalds <torvalds@linux-foundation.org> |
| Cc: Randy Dunlap <rdunlap@infradead.org> |
| Cc: Steven Price <steven.price@arm.com> |
| Cc: Phil Auld <pauld@redhat.com> |
| Link: https://lkml.kernel.org/r/245a606e1a42a558a310220312d9b6adb9159df6.1555085500.git.jpoimboe@redhat.com |
| Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
| --- |
| 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 31c17532c219..49aa191979c1 100644 |
| --- a/Documentation/admin-guide/kernel-parameters.txt |
| +++ b/Documentation/admin-guide/kernel-parameters.txt |
| @@ -2503,7 +2503,7 @@ |
| 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. |
| @@ -2512,10 +2512,11 @@ |
| 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 1341325599a7..4ccbf611a3c5 100644 |
| --- a/arch/powerpc/kernel/security.c |
| +++ b/arch/powerpc/kernel/security.c |
| @@ -56,7 +56,7 @@ 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); |
| } |
| |
| @@ -115,7 +115,7 @@ 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; |
| @@ -299,7 +299,7 @@ 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 faf00222b324..eaf7300be5ab 100644 |
| --- a/arch/powerpc/kernel/setup_64.c |
| +++ b/arch/powerpc/kernel/setup_64.c |
| @@ -955,7 +955,7 @@ 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); |
| } |
| |
| -- |
| 2.21.0 |
| |