From: Will Deacon <will@kernel.org>
To: linux-arm-kernel@lists.infradead.org
Cc: Catalin Marinas <catalin.marinas@arm.com>,
David Brazdil <dbrazdil@google.com>,
Will Deacon <will@kernel.org>,
Suzuki K Poulose <suzuki.poulose@arm.com>
Subject: [PATCH 07/19] arm64: Rename ARM64_HARDEN_BRANCH_PREDICTOR to ARM64_SPECTRE_V2
Date: Fri, 18 Sep 2020 17:47:17 +0100 [thread overview]
Message-ID: <20200918164729.31994-8-will@kernel.org> (raw)
In-Reply-To: <20200918164729.31994-1-will@kernel.org>
For better or worse, the world knows about "Spectre" and not about
"Branch predictor hardening". Rename ARM64_HARDEN_BRANCH_PREDICTOR to
ARM64_SPECTRE_V2 as part of moving all of the Spectre mitigations into
their own little corner.
Signed-off-by: Will Deacon <will@kernel.org>
---
arch/arm64/include/asm/cpucaps.h | 2 +-
arch/arm64/include/asm/kvm_mmu.h | 27 +++++++++++++--------------
arch/arm64/include/asm/mmu.h | 2 +-
arch/arm64/kernel/cpu_errata.c | 2 +-
4 files changed, 16 insertions(+), 17 deletions(-)
diff --git a/arch/arm64/include/asm/cpucaps.h b/arch/arm64/include/asm/cpucaps.h
index 07b643a70710..348bfcf6c818 100644
--- a/arch/arm64/include/asm/cpucaps.h
+++ b/arch/arm64/include/asm/cpucaps.h
@@ -31,7 +31,7 @@
#define ARM64_HAS_DCPOP 21
#define ARM64_SVE 22
#define ARM64_UNMAP_KERNEL_AT_EL0 23
-#define ARM64_HARDEN_BRANCH_PREDICTOR 24
+#define ARM64_SPECTRE_V2 24
#define ARM64_HAS_RAS_EXTN 25
#define ARM64_WORKAROUND_843419 26
#define ARM64_HAS_CACHE_IDC 27
diff --git a/arch/arm64/include/asm/kvm_mmu.h b/arch/arm64/include/asm/kvm_mmu.h
index dfd176b0642e..873e12430ac7 100644
--- a/arch/arm64/include/asm/kvm_mmu.h
+++ b/arch/arm64/include/asm/kvm_mmu.h
@@ -435,14 +435,13 @@ static inline int kvm_write_guest_lock(struct kvm *kvm, gpa_t gpa,
* EL2 vectors can be mapped and rerouted in a number of ways,
* depending on the kernel configuration and CPU present:
*
- * - If the CPU has the ARM64_HARDEN_BRANCH_PREDICTOR cap, the
- * hardening sequence is placed in one of the vector slots, which is
- * executed before jumping to the real vectors.
+ * - If the CPU is affected by Spectre-v2, the hardening sequence is
+ * placed in one of the vector slots, which is executed before jumping
+ * to the real vectors.
*
- * - If the CPU has both the ARM64_HARDEN_EL2_VECTORS cap and the
- * ARM64_HARDEN_BRANCH_PREDICTOR cap, the slot containing the
- * hardening sequence is mapped next to the idmap page, and executed
- * before jumping to the real vectors.
+ * - If the CPU also has the ARM64_HARDEN_EL2_VECTORS cap, the slot
+ * containing the hardening sequence is mapped next to the idmap page,
+ * and executed before jumping to the real vectors.
*
* - If the CPU only has the ARM64_HARDEN_EL2_VECTORS cap, then an
* empty slot is selected, mapped next to the idmap page, and
@@ -464,7 +463,7 @@ static inline void *kvm_get_hyp_vector(void)
void *vect = kern_hyp_va(kvm_ksym_ref(__kvm_hyp_vector));
int slot = -1;
- if (cpus_have_const_cap(ARM64_HARDEN_BRANCH_PREDICTOR) && data->fn) {
+ if (cpus_have_const_cap(ARM64_SPECTRE_V2) && data->fn) {
vect = kern_hyp_va(kvm_ksym_ref(__bp_harden_hyp_vecs));
slot = data->hyp_vectors_slot;
}
@@ -485,15 +484,15 @@ static inline void *kvm_get_hyp_vector(void)
static inline int kvm_map_vectors(void)
{
/*
- * HBP = ARM64_HARDEN_BRANCH_PREDICTOR
+ * SV2 = ARM64_SPECTRE_V2
* HEL2 = ARM64_HARDEN_EL2_VECTORS
*
- * !HBP + !HEL2 -> use direct vectors
- * HBP + !HEL2 -> use hardened vectors in place
- * !HBP + HEL2 -> allocate one vector slot and use exec mapping
- * HBP + HEL2 -> use hardened vertors and use exec mapping
+ * !SV2 + !HEL2 -> use direct vectors
+ * SV2 + !HEL2 -> use hardened vectors in place
+ * !SV2 + HEL2 -> allocate one vector slot and use exec mapping
+ * SV2 + HEL2 -> use hardened vertors and use exec mapping
*/
- if (cpus_have_const_cap(ARM64_HARDEN_BRANCH_PREDICTOR)) {
+ if (cpus_have_const_cap(ARM64_SPECTRE_V2)) {
__kvm_bp_vect_base = kvm_ksym_ref(__bp_harden_hyp_vecs);
__kvm_bp_vect_base = kern_hyp_va(__kvm_bp_vect_base);
}
diff --git a/arch/arm64/include/asm/mmu.h b/arch/arm64/include/asm/mmu.h
index f5e3efeb5b97..cbff2d42c1d8 100644
--- a/arch/arm64/include/asm/mmu.h
+++ b/arch/arm64/include/asm/mmu.h
@@ -56,7 +56,7 @@ static inline void arm64_apply_bp_hardening(void)
{
struct bp_hardening_data *d;
- if (!cpus_have_const_cap(ARM64_HARDEN_BRANCH_PREDICTOR))
+ if (!cpus_have_const_cap(ARM64_SPECTRE_V2))
return;
d = arm64_get_bp_hardening_data();
diff --git a/arch/arm64/kernel/cpu_errata.c b/arch/arm64/kernel/cpu_errata.c
index a72ca57f5630..b275f2d5e7a3 100644
--- a/arch/arm64/kernel/cpu_errata.c
+++ b/arch/arm64/kernel/cpu_errata.c
@@ -877,7 +877,7 @@ const struct arm64_cpu_capabilities arm64_errata[] = {
#endif
{
.desc = "Branch predictor hardening",
- .capability = ARM64_HARDEN_BRANCH_PREDICTOR,
+ .capability = ARM64_SPECTRE_V2,
.type = ARM64_CPUCAP_LOCAL_CPU_ERRATUM,
.matches = check_branch_predictor,
.cpu_enable = cpu_enable_branch_predictor_hardening,
--
2.28.0.681.g6f77f65b4e-goog
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next prev parent reply other threads:[~2020-09-18 16:51 UTC|newest]
Thread overview: 23+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-09-18 16:47 [PATCH 00/19] Fix and rewrite arm64 spectre mitigations Will Deacon
2020-09-18 16:47 ` [PATCH 01/19] arm64: Make use of ARCH_WORKAROUND_1 even when KVM is not enabled Will Deacon
2020-09-18 16:47 ` [PATCH 02/19] arm64: Run ARCH_WORKAROUND_1 enabling code on all CPUs Will Deacon
2020-09-21 12:54 ` Sasha Levin
2020-09-18 16:47 ` [PATCH 03/19] arm64: Run ARCH_WORKAROUND_2 " Will Deacon
2020-09-18 17:13 ` Suzuki K Poulose
2020-09-18 16:47 ` [PATCH 04/19] arm64: Remove Spectre-related CONFIG_* options Will Deacon
2020-09-18 16:47 ` [PATCH 05/19] KVM: arm64: Replace CONFIG_KVM_INDIRECT_VECTORS with CONFIG_RANDOMIZE_BASE Will Deacon
2020-09-18 16:47 ` [PATCH 06/19] KVM: arm64: Simplify install_bp_hardening_cb() Will Deacon
2020-09-18 16:47 ` Will Deacon [this message]
2020-09-18 16:47 ` [PATCH 08/19] arm64: Introduce separate file for spectre mitigations and reporting Will Deacon
2020-09-18 16:47 ` [PATCH 09/19] arm64: Rewrite Spectre-v2 mitigation code Will Deacon
2020-09-18 16:47 ` [PATCH 10/19] KVM: arm64: Set CSV2 for guests on hardware unaffected by Spectre-v2 Will Deacon
2020-09-18 16:47 ` [PATCH 11/19] arm64: Group start_thread() functions together Will Deacon
2020-09-18 16:47 ` [PATCH 12/19] arm64: Treat SSBS as a non-strict system feature Will Deacon
2020-09-18 16:47 ` [PATCH 13/19] arm64: Rename ARM64_SSBD to ARM64_SPECTRE_V4 Will Deacon
2020-09-18 16:47 ` [PATCH 14/19] arm64: Move SSBD prctl() handler alongside other spectre mitigation code Will Deacon
2020-09-18 16:47 ` [PATCH 15/19] arm64: Rewrite Spectre-v4 " Will Deacon
2020-09-18 16:47 ` [PATCH 16/19] KVM: arm64: Simplify handling of ARCH_WORKAROUND_2 Will Deacon
2020-09-18 16:47 ` [PATCH 17/19] KVM: arm64: Get rid of kvm_arm_have_ssbd() Will Deacon
2020-09-18 16:47 ` [PATCH 18/19] KVM: arm64: Convert ARCH_WORKAROUND_2 to arm64_get_spectre_v4_state() Will Deacon
2020-09-18 16:47 ` [PATCH 19/19] arm64: Get rid of arm64_ssbd_state Will Deacon
2020-09-18 16:59 ` [PATCH 00/19] Fix and rewrite arm64 spectre mitigations Will Deacon
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