Since ARM64_HARDEN_EL2_VECTORS is really a mitigation for Spectre-v3a,
rename it accordingly for consistency with the v2 and v4 mitigation.
Cc: Marc Zyngier <maz@xxxxxxxxxx>
Cc: Quentin Perret <qperret@xxxxxxxxxx>
Signed-off-by: Will Deacon <will@xxxxxxxxxx>
---
Documentation/arm64/memory.rst | 2 +-
arch/arm64/include/asm/cpucaps.h | 2 +-
arch/arm64/include/asm/spectre.h | 2 +-
arch/arm64/kernel/cpu_errata.c | 6 +++---
arch/arm64/kernel/proton-pack.c | 13 ++++++++++---
arch/arm64/kvm/arm.c | 8 ++++----
arch/arm64/kvm/hyp/hyp-entry.S | 3 +--
arch/arm64/kvm/va_layout.c | 4 +---
8 files changed, 22 insertions(+), 18 deletions(-)
diff --git a/Documentation/arm64/memory.rst b/Documentation/arm64/memory.rst
index cf03b3290800..75df7fb30a7b 100644
--- a/Documentation/arm64/memory.rst
+++ b/Documentation/arm64/memory.rst
@@ -100,7 +100,7 @@ hypervisor maps kernel pages in EL2 at a fixed (and potentially
random) offset from the linear mapping. See the kern_hyp_va macro and
kvm_update_va_mask function for more details. MMIO devices such as
GICv2 gets mapped next to the HYP idmap page, as do vectors when
-ARM64_HARDEN_EL2_VECTORS is selected for particular CPUs.
+ARM64_SPECTRE_V3A is enabled for particular CPUs.
When using KVM with the Virtualization Host Extensions, no additional
mappings are created, since the host kernel runs directly in EL2.
diff --git a/arch/arm64/include/asm/cpucaps.h b/arch/arm64/include/asm/cpucaps.h
index 42868dbd29fd..cc22c1032918 100644
--- a/arch/arm64/include/asm/cpucaps.h
+++ b/arch/arm64/include/asm/cpucaps.h
@@ -21,7 +21,7 @@
#define ARM64_HAS_VIRT_HOST_EXTN 11
#define ARM64_WORKAROUND_CAVIUM_27456 12
#define ARM64_HAS_32BIT_EL0 13
-#define ARM64_HARDEN_EL2_VECTORS 14
+#define ARM64_SPECTRE_V3A 14
#define ARM64_HAS_CNP 15
#define ARM64_HAS_NO_FPSIMD 16
#define ARM64_WORKAROUND_REPEAT_TLBI 17
diff --git a/arch/arm64/include/asm/spectre.h b/arch/arm64/include/asm/spectre.h
index fa86b8f655b7..b4df683ed800 100644
--- a/arch/arm64/include/asm/spectre.h
+++ b/arch/arm64/include/asm/spectre.h
@@ -83,7 +83,7 @@ enum mitigation_state arm64_get_spectre_v2_state(void);
bool has_spectre_v2(const struct arm64_cpu_capabilities *cap, int scope);
void spectre_v2_enable_mitigation(const struct arm64_cpu_capabilities *__unused);
-void cpu_el2_vector_harden_enable(const struct arm64_cpu_capabilities *__unused);
+void spectre_v3a_enable_mitigation(const struct arm64_cpu_capabilities *__unused);
enum mitigation_state arm64_get_spectre_v4_state(void);
bool has_spectre_v4(const struct arm64_cpu_capabilities *cap, int scope);
diff --git a/arch/arm64/kernel/cpu_errata.c b/arch/arm64/kernel/cpu_errata.c
index f8a70b406134..1b0c432d577d 100644
--- a/arch/arm64/kernel/cpu_errata.c
+++ b/arch/arm64/kernel/cpu_errata.c
@@ -460,10 +460,10 @@ const struct arm64_cpu_capabilities arm64_errata[] = {
#ifdef CONFIG_RANDOMIZE_BASE
{
/* Must come after the Spectre-v2 entry */
- .desc = "EL2 vector hardening",
- .capability = ARM64_HARDEN_EL2_VECTORS,
+ .desc = "Spectre-v3a",
+ .capability = ARM64_SPECTRE_V3A,
ERRATA_MIDR_RANGE_LIST(ca57_a72),
- .cpu_enable = cpu_el2_vector_harden_enable,
+ .cpu_enable = spectre_v3a_enable_mitigation,
},
#endif
{
diff --git a/arch/arm64/kernel/proton-pack.c b/arch/arm64/kernel/proton-pack.c
index 499c19cf64fb..672dfda73881 100644
--- a/arch/arm64/kernel/proton-pack.c
+++ b/arch/arm64/kernel/proton-pack.c
@@ -1,6 +1,6 @@
// SPDX-License-Identifier: GPL-2.0-only
/*
- * Handle detection, reporting and mitigation of Spectre v1, v2 and v4, as
+ * Handle detection, reporting and mitigation of Spectre v1, v2, v3a and v4, as
* detailed at:
*
* https://developer.arm.com/support/arm-security-updates/speculative-processor-vulnerability
@@ -272,11 +272,18 @@ void spectre_v2_enable_mitigation(const struct arm64_cpu_capabilities *__unused)
update_mitigation_state(&spectre_v2_state, state);
}
-void cpu_el2_vector_harden_enable(const struct arm64_cpu_capabilities *__unused)
+/*
+ * Spectre-v3a.
+ *
+ * Phew, there's not an awful lot to do here! We just instruct EL2 to use
+ * an indirect trampoline for the hyp vectors so that guests can't read
+ * VBAR_EL2 to defeat randomisation of the hypervisor VA layout.
+ */
+void spectre_v3a_enable_mitigation(const struct arm64_cpu_capabilities *__unused)
{
struct bp_hardening_data *data = this_cpu_ptr(&bp_hardening_data);
- if (this_cpu_has_cap(ARM64_HARDEN_EL2_VECTORS))
+ if (this_cpu_has_cap(ARM64_SPECTRE_V3A))
data->slot += HYP_VECTOR_INDIRECT;
}
diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c
index 531c4a0a12c2..c15176543473 100644
--- a/arch/arm64/kvm/arm.c
+++ b/arch/arm64/kvm/arm.c
@@ -1295,7 +1295,7 @@ static int kvm_init_vector_slots(void)
base = kern_hyp_va(kvm_ksym_ref(__bp_harden_hyp_vecs));
kvm_init_vector_slot(base, HYP_VECTOR_SPECTRE_DIRECT);
- if (!cpus_have_const_cap(ARM64_HARDEN_EL2_VECTORS))
+ if (!cpus_have_const_cap(ARM64_SPECTRE_V3A))
return 0;
err = create_hyp_exec_mappings(__pa_symbol(__bp_harden_hyp_vecs),
@@ -1367,15 +1367,15 @@ static void cpu_hyp_reset(void)
* placed in one of the vector slots, which is executed before jumping
* to the real vectors.
*
- * - If the CPU also has the ARM64_HARDEN_EL2_VECTORS cap, the slot
+ * - If the CPU also has the ARM64_SPECTRE_V3A 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
+ * - If the CPU only has the ARM64_SPECTRE_V3A cap, then an
* empty slot is selected, mapped next to the idmap page, and
* executed before jumping to the real vectors.
*
- * Note that ARM64_HARDEN_EL2_VECTORS is somewhat incompatible with
+ * Note that ARM64_SPECTRE_V3A is somewhat incompatible with
* VHE, as we don't have hypervisor-specific mappings. If the system
* is VHE and yet selects this capability, it will be ignored.
*/
diff --git a/arch/arm64/kvm/hyp/hyp-entry.S b/arch/arm64/kvm/hyp/hyp-entry.S
index f5e126e82db2..9d074ec34b1c 100644
--- a/arch/arm64/kvm/hyp/hyp-entry.S
+++ b/arch/arm64/kvm/hyp/hyp-entry.S
@@ -209,8 +209,7 @@ SYM_CODE_END(__kvm_hyp_vector)
.if \indirect != 0
alternative_cb kvm_patch_vector_branch
/*
- * For ARM64_HARDEN_EL2_VECTORS configurations, these NOPs get replaced
- * with:
+ * For ARM64_SPECTRE_V3A configurations, these NOPs get replaced with:
*
* movz x0, #(addr & 0xffff)
* movk x0, #((addr >> 16) & 0xffff), lsl #16
diff --git a/arch/arm64/kvm/va_layout.c b/arch/arm64/kvm/va_layout.c
index 1ae327006815..0782e4711aa2 100644
--- a/arch/arm64/kvm/va_layout.c
+++ b/arch/arm64/kvm/va_layout.c
@@ -139,10 +139,8 @@ void kvm_patch_vector_branch(struct alt_instr *alt,
BUG_ON(nr_inst != 3);
- if (!cpus_have_const_cap(ARM64_HARDEN_EL2_VECTORS) ||
- WARN_ON_ONCE(has_vhe())) {
+ if (!cpus_have_const_cap(ARM64_SPECTRE_V3A) || WARN_ON_ONCE(has_vhe()))
return;
- }
/*
* Compute HYP VA by using the same computation as kern_hyp_va()
--
2.29.0.rc2.309.g374f81d7ae-goog
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