From: Josh Poimboeuf <jpoimboe@redhat.com>
To: linux-kernel@vger.kernel.org
Cc: Peter Zijlstra <peterz@infradead.org>,
Heiko Carstens <heiko.carstens@de.ibm.com>,
Paul Mackerras <paulus@samba.org>,
"H . Peter Anvin" <hpa@zytor.com>, Ingo Molnar <mingo@kernel.org>,
Andrea Arcangeli <aarcange@redhat.com>,
linux-s390@vger.kernel.org, x86@kernel.org,
Will Deacon <will.deacon@arm.com>,
Linus Torvalds <torvalds@linux-foundation.org>,
Catalin Marinas <catalin.marinas@arm.com>,
Waiman Long <longman@redhat.com>,
linux-arch@vger.kernel.org, Jon Masters <jcm@redhat.com>,
Jiri Kosina <jikos@kernel.org>, Borislav Petkov <bp@alien8.de>,
Andy Lutomirski <luto@kernel.org>,
Thomas Gleixner <tglx@linutronix.de>,
linux-arm-kernel@lists.infradead.org,
Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
Tyler Hicks <tyhicks@canonical.com>,
Martin Schwidefsky <schwidefsky@de.ibm.com>,
linuxppc-dev@lists.ozlabs.org
Subject: [PATCH RFC 5/5] arm64/speculation: Add support for 'cpu_spec_mitigations=' cmdline options
Date: Thu, 4 Apr 2019 11:44:15 -0500 [thread overview]
Message-ID: <5f70df57b19bbccc4a0d5d76134b4681c9a50b0b.1554396090.git.jpoimboe@redhat.com> (raw)
In-Reply-To: <cover.1554396090.git.jpoimboe@redhat.com>
Configure arm64 runtime CPU speculation bug mitigations in accordance
with the 'cpu_spec_mitigations=' cmdline options. This affects
Meltdown and Speculative Store Bypass.
The default behavior is unchanged.
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
---
Documentation/admin-guide/kernel-parameters.txt | 2 ++
arch/arm64/kernel/cpu_errata.c | 4 ++++
arch/arm64/kernel/cpufeature.c | 6 ++++++
3 files changed, 12 insertions(+)
diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt
index e838af96daa4..0b54385ee7a8 100644
--- a/Documentation/admin-guide/kernel-parameters.txt
+++ b/Documentation/admin-guide/kernel-parameters.txt
@@ -2553,11 +2553,13 @@
off
Disable all speculative CPU mitigations.
Equivalent to: nopti [x86, powerpc]
+ kpti=0 [arm64]
nospectre_v1 [powerpc]
nospectre_v2 [x86, powerpc, s390]
spectre_v2_user=off [x86]
nobp=0 [s390]
spec_store_bypass_disable=off [x86, powerpc]
+ ssbd=force-off [arm64]
l1tf=off [x86]
auto (default)
diff --git a/arch/arm64/kernel/cpu_errata.c b/arch/arm64/kernel/cpu_errata.c
index 9950bb0cbd52..db8d27e3fb1c 100644
--- a/arch/arm64/kernel/cpu_errata.c
+++ b/arch/arm64/kernel/cpu_errata.c
@@ -19,6 +19,7 @@
#include <linux/arm-smccc.h>
#include <linux/psci.h>
#include <linux/types.h>
+#include <linux/cpu.h>
#include <asm/cpu.h>
#include <asm/cputype.h>
#include <asm/cpufeature.h>
@@ -385,6 +386,9 @@ static bool has_ssbd_mitigation(const struct arm64_cpu_capabilities *entry,
return false;
}
+ if (cpu_spec_mitigations == CPU_SPEC_MITIGATIONS_OFF)
+ ssbd_state = ARM64_SSBD_FORCE_DISABLE;
+
switch (psci_ops.conduit) {
case PSCI_CONDUIT_HVC:
arm_smccc_1_1_hvc(ARM_SMCCC_ARCH_FEATURES_FUNC_ID,
diff --git a/arch/arm64/kernel/cpufeature.c b/arch/arm64/kernel/cpufeature.c
index 4061de10cea6..4512b582d50f 100644
--- a/arch/arm64/kernel/cpufeature.c
+++ b/arch/arm64/kernel/cpufeature.c
@@ -25,6 +25,7 @@
#include <linux/stop_machine.h>
#include <linux/types.h>
#include <linux/mm.h>
+#include <linux/cpu.h>
#include <asm/cpu.h>
#include <asm/cpufeature.h>
#include <asm/cpu_ops.h>
@@ -978,6 +979,11 @@ static bool unmap_kernel_at_el0(const struct arm64_cpu_capabilities *entry,
__kpti_forced = -1;
}
+ if (cpu_spec_mitigations == CPU_SPEC_MITIGATIONS_OFF) {
+ str = "cpu_spec_mitigations=off";
+ __kpti_forced = -1;
+ }
+
/* Forced? */
if (__kpti_forced) {
pr_info_once("kernel page table isolation forced %s by %s\n",
--
2.17.2
next prev parent reply other threads:[~2019-04-04 16:55 UTC|newest]
Thread overview: 33+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-04-04 16:44 [PATCH RFC 0/5] cpu/speculation: Add 'cpu_spec_mitigations=' cmdline options Josh Poimboeuf
2019-04-04 16:44 ` [PATCH RFC 1/5] " Josh Poimboeuf
2019-04-04 16:49 ` Josh Poimboeuf
2019-04-05 13:12 ` Borislav Petkov
2019-04-05 14:20 ` Josh Poimboeuf
2019-04-05 15:20 ` Borislav Petkov
2019-04-05 16:01 ` Borislav Petkov
2019-04-05 16:18 ` Josh Poimboeuf
2019-04-10 5:48 ` Michael Ellerman
2019-04-10 8:30 ` Borislav Petkov
2019-04-10 12:10 ` Thomas Gleixner
2019-04-11 13:15 ` Josh Poimboeuf
2019-04-12 2:41 ` Michael Ellerman
2019-04-12 2:29 ` Michael Ellerman
2019-04-04 16:44 ` [PATCH RFC 2/5] x86/speculation: Add support for " Josh Poimboeuf
2019-04-05 13:57 ` Borislav Petkov
2019-04-05 14:31 ` Josh Poimboeuf
2019-04-05 15:26 ` Borislav Petkov
2019-04-05 16:05 ` Josh Poimboeuf
2019-04-05 15:18 ` Randy Dunlap
2019-04-05 15:30 ` Josh Poimboeuf
2019-04-04 16:44 ` [PATCH RFC 3/5] powerpc/speculation: " Josh Poimboeuf
2019-04-04 19:49 ` Jiri Kosina
2019-04-04 20:01 ` Timothy Pearson
2019-04-10 6:06 ` Michael Ellerman
2019-04-11 4:02 ` Josh Poimboeuf
2019-04-04 16:44 ` [PATCH RFC 4/5] s390/speculation: " Josh Poimboeuf
2019-04-04 16:44 ` Josh Poimboeuf [this message]
2019-04-05 14:39 ` [PATCH RFC 5/5] arm64/speculation: " Steven Price
2019-04-05 14:43 ` Josh Poimboeuf
2019-04-05 14:44 ` Will Deacon
2019-04-05 16:03 ` Josh Poimboeuf
2019-04-04 16:50 ` [PATCH RFC 0/5] cpu/speculation: Add " Waiman Long
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