[PATCH 4.14 065/119] arm64: KVM: Use SMCCC_ARCH_WORKAROUND_1 for Falkor BP hardening
From: Greg Kroah-Hartman
Date: Sun Oct 27 2019 - 17:09:46 EST
From: Shanker Donthineni <shankerd@xxxxxxxxxxxxxx>
[ Upstream commit 4bc352ffb39e4eec253e70f8c076f2f48a6c1926 ]
The function SMCCC_ARCH_WORKAROUND_1 was introduced as part of SMC
V1.1 Calling Convention to mitigate CVE-2017-5715. This patch uses
the standard call SMCCC_ARCH_WORKAROUND_1 for Falkor chips instead
of Silicon provider service ID 0xC2001700.
Cc: <stable@xxxxxxxxxxxxxxx> # 4.14+
Signed-off-by: Shanker Donthineni <shankerd@xxxxxxxxxxxxxx>
[maz: reworked errata framework integration]
Signed-off-by: Marc Zyngier <marc.zyngier@xxxxxxx>
Signed-off-by: Will Deacon <will.deacon@xxxxxxx>
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
arch/arm64/include/asm/cpucaps.h | 7 ++---
arch/arm64/include/asm/kvm_asm.h | 2 -
arch/arm64/kernel/bpi.S | 7 -----
arch/arm64/kernel/cpu_errata.c | 54 ++++++++++++---------------------------
arch/arm64/kvm/hyp/entry.S | 12 --------
arch/arm64/kvm/hyp/switch.c | 10 -------
6 files changed, 20 insertions(+), 72 deletions(-)
--- a/arch/arm64/include/asm/cpucaps.h
+++ b/arch/arm64/include/asm/cpucaps.h
@@ -42,10 +42,9 @@
#define ARM64_HAS_DCPOP 21
#define ARM64_UNMAP_KERNEL_AT_EL0 23
#define ARM64_HARDEN_BRANCH_PREDICTOR 24
-#define ARM64_HARDEN_BP_POST_GUEST_EXIT 25
-#define ARM64_SSBD 26
-#define ARM64_MISMATCHED_CACHE_TYPE 27
+#define ARM64_SSBD 25
+#define ARM64_MISMATCHED_CACHE_TYPE 26
-#define ARM64_NCAPS 28
+#define ARM64_NCAPS 27
#endif /* __ASM_CPUCAPS_H */
--- a/arch/arm64/include/asm/kvm_asm.h
+++ b/arch/arm64/include/asm/kvm_asm.h
@@ -70,8 +70,6 @@ extern u32 __kvm_get_mdcr_el2(void);
extern u32 __init_stage2_translation(void);
-extern void __qcom_hyp_sanitize_btac_predictors(void);
-
/* Home-grown __this_cpu_{ptr,read} variants that always work at HYP */
#define __hyp_this_cpu_ptr(sym) \
({ \
--- a/arch/arm64/kernel/bpi.S
+++ b/arch/arm64/kernel/bpi.S
@@ -55,13 +55,6 @@ ENTRY(__bp_harden_hyp_vecs_start)
.endr
ENTRY(__bp_harden_hyp_vecs_end)
-ENTRY(__qcom_hyp_sanitize_link_stack_start)
- stp x29, x30, [sp, #-16]!
- .rept 16
- bl . + 4
- .endr
- ldp x29, x30, [sp], #16
-ENTRY(__qcom_hyp_sanitize_link_stack_end)
.macro smccc_workaround_1 inst
sub sp, sp, #(8 * 4)
--- a/arch/arm64/kernel/cpu_errata.c
+++ b/arch/arm64/kernel/cpu_errata.c
@@ -83,8 +83,6 @@ cpu_enable_trap_ctr_access(const struct
DEFINE_PER_CPU_READ_MOSTLY(struct bp_hardening_data, bp_hardening_data);
#ifdef CONFIG_KVM
-extern char __qcom_hyp_sanitize_link_stack_start[];
-extern char __qcom_hyp_sanitize_link_stack_end[];
extern char __smccc_workaround_1_smc_start[];
extern char __smccc_workaround_1_smc_end[];
extern char __smccc_workaround_1_hvc_start[];
@@ -131,8 +129,6 @@ static void __install_bp_hardening_cb(bp
spin_unlock(&bp_lock);
}
#else
-#define __qcom_hyp_sanitize_link_stack_start NULL
-#define __qcom_hyp_sanitize_link_stack_end NULL
#define __smccc_workaround_1_smc_start NULL
#define __smccc_workaround_1_smc_end NULL
#define __smccc_workaround_1_hvc_start NULL
@@ -177,12 +173,25 @@ static void call_hvc_arch_workaround_1(v
arm_smccc_1_1_hvc(ARM_SMCCC_ARCH_WORKAROUND_1, NULL);
}
+static void qcom_link_stack_sanitization(void)
+{
+ u64 tmp;
+
+ asm volatile("mov %0, x30 \n"
+ ".rept 16 \n"
+ "bl . + 4 \n"
+ ".endr \n"
+ "mov x30, %0 \n"
+ : "=&r" (tmp));
+}
+
static void
enable_smccc_arch_workaround_1(const struct arm64_cpu_capabilities *entry)
{
bp_hardening_cb_t cb;
void *smccc_start, *smccc_end;
struct arm_smccc_res res;
+ u32 midr = read_cpuid_id();
if (!entry->matches(entry, SCOPE_LOCAL_CPU))
return;
@@ -215,30 +224,14 @@ enable_smccc_arch_workaround_1(const str
return;
}
+ if (((midr & MIDR_CPU_MODEL_MASK) == MIDR_QCOM_FALKOR) ||
+ ((midr & MIDR_CPU_MODEL_MASK) == MIDR_QCOM_FALKOR_V1))
+ cb = qcom_link_stack_sanitization;
+
install_bp_hardening_cb(entry, cb, smccc_start, smccc_end);
return;
}
-
-static void qcom_link_stack_sanitization(void)
-{
- u64 tmp;
-
- asm volatile("mov %0, x30 \n"
- ".rept 16 \n"
- "bl . + 4 \n"
- ".endr \n"
- "mov x30, %0 \n"
- : "=&r" (tmp));
-}
-
-static void
-qcom_enable_link_stack_sanitization(const struct arm64_cpu_capabilities *entry)
-{
- install_bp_hardening_cb(entry, qcom_link_stack_sanitization,
- __qcom_hyp_sanitize_link_stack_start,
- __qcom_hyp_sanitize_link_stack_end);
-}
#endif /* CONFIG_HARDEN_BRANCH_PREDICTOR */
#ifdef CONFIG_ARM64_SSBD
@@ -463,10 +456,6 @@ static const struct midr_range arm64_bp_
MIDR_ALL_VERSIONS(MIDR_CORTEX_A75),
MIDR_ALL_VERSIONS(MIDR_BRCM_VULCAN),
MIDR_ALL_VERSIONS(MIDR_CAVIUM_THUNDERX2),
- {},
-};
-
-static const struct midr_range qcom_bp_harden_cpus[] = {
MIDR_ALL_VERSIONS(MIDR_QCOM_FALKOR_V1),
MIDR_ALL_VERSIONS(MIDR_QCOM_FALKOR),
{},
@@ -618,15 +607,6 @@ const struct arm64_cpu_capabilities arm6
ERRATA_MIDR_RANGE_LIST(arm64_bp_harden_smccc_cpus),
.cpu_enable = enable_smccc_arch_workaround_1,
},
- {
- .capability = ARM64_HARDEN_BRANCH_PREDICTOR,
- ERRATA_MIDR_RANGE_LIST(qcom_bp_harden_cpus),
- .cpu_enable = qcom_enable_link_stack_sanitization,
- },
- {
- .capability = ARM64_HARDEN_BP_POST_GUEST_EXIT,
- ERRATA_MIDR_RANGE_LIST(qcom_bp_harden_cpus),
- },
#endif
#ifdef CONFIG_ARM64_SSBD
{
--- a/arch/arm64/kvm/hyp/entry.S
+++ b/arch/arm64/kvm/hyp/entry.S
@@ -196,15 +196,3 @@ alternative_endif
eret
ENDPROC(__fpsimd_guest_restore)
-
-ENTRY(__qcom_hyp_sanitize_btac_predictors)
- /**
- * Call SMC64 with Silicon provider serviceID 23<<8 (0xc2001700)
- * 0xC2000000-0xC200FFFF: assigned to SiP Service Calls
- * b15-b0: contains SiP functionID
- */
- movz x0, #0x1700
- movk x0, #0xc200, lsl #16
- smc #0
- ret
-ENDPROC(__qcom_hyp_sanitize_btac_predictors)
--- a/arch/arm64/kvm/hyp/switch.c
+++ b/arch/arm64/kvm/hyp/switch.c
@@ -405,16 +405,6 @@ again:
__set_host_arch_workaround_state(vcpu);
- if (cpus_have_const_cap(ARM64_HARDEN_BP_POST_GUEST_EXIT)) {
- u32 midr = read_cpuid_id();
-
- /* Apply BTAC predictors mitigation to all Falkor chips */
- if (((midr & MIDR_CPU_MODEL_MASK) == MIDR_QCOM_FALKOR) ||
- ((midr & MIDR_CPU_MODEL_MASK) == MIDR_QCOM_FALKOR_V1)) {
- __qcom_hyp_sanitize_btac_predictors();
- }
- }
-
fp_enabled = __fpsimd_enabled();
__sysreg_save_guest_state(guest_ctxt);