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);
}
|