The patch below does not apply to the 4.16-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable@xxxxxxxxxxxxxxx>.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
>From f9f5dc19509bbef6f5e675346f1a7d7b846bdb12 Mon Sep 17 00:00:00 2001
From: Shanker Donthineni <shankerd@xxxxxxxxxxxxxx>
Date: Mon, 5 Mar 2018 11:06:43 -0600
Subject: [PATCH] arm64: KVM: Use SMCCC_ARCH_WORKAROUND_1 for Falkor BP
hardening
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>
Signed-off-by: Marc Zyngier <marc.zyngier@xxxxxxx>
diff --git a/arch/arm64/include/asm/cpucaps.h b/arch/arm64/include/asm/cpucaps.h
index d4cc54ed0656..c7dfe68fbcc7 100644
--- a/arch/arm64/include/asm/cpucaps.h
+++ b/arch/arm64/include/asm/cpucaps.h
@@ -43,7 +43,7 @@
#define ARM64_SVE 22
#define ARM64_UNMAP_KERNEL_AT_EL0 23
#define ARM64_HARDEN_BRANCH_PREDICTOR 24
-#define ARM64_HARDEN_BP_POST_GUEST_EXIT 25
+/* #define ARM64_UNUSED_CAP_TO_BE_REMOVED 25 */
#define ARM64_HAS_RAS_EXTN 26
#define ARM64_NCAPS 27
diff --git a/arch/arm64/include/asm/kvm_asm.h b/arch/arm64/include/asm/kvm_asm.h
index d53d40704416..f6648a3e4152 100644
--- a/arch/arm64/include/asm/kvm_asm.h
+++ b/arch/arm64/include/asm/kvm_asm.h
@@ -71,8 +71,6 @@ extern u32 __kvm_get_mdcr_el2(void);
extern u32 __init_stage2_translation(void);
-extern void __qcom_hyp_sanitize_btac_predictors(void);
-
#else /* __ASSEMBLY__ */
.macro get_host_ctxt reg, tmp
diff --git a/arch/arm64/kernel/bpi.S b/arch/arm64/kernel/bpi.S
index bb0b67722e86..9404f6aecda7 100644
--- a/arch/arm64/kernel/bpi.S
+++ b/arch/arm64/kernel/bpi.S
@@ -74,14 +74,6 @@ ENTRY(__bp_harden_hyp_vecs_end)
.popsection
-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)
stp x2, x3, [sp, #(8 * 0)]
diff --git a/arch/arm64/kernel/cpu_errata.c b/arch/arm64/kernel/cpu_errata.c
index aacdc118c4c9..caa73af7d26e 100644
--- a/arch/arm64/kernel/cpu_errata.c
+++ b/arch/arm64/kernel/cpu_errata.c
@@ -69,8 +69,6 @@ atomic_t arm64_el2_vector_last_slot = ATOMIC_INIT(-1);
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[];
@@ -114,8 +112,6 @@ static void __install_bp_hardening_cb(bp_hardening_cb_t fn,
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
@@ -160,12 +156,25 @@ static void call_hvc_arch_workaround_1(void)
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 int enable_smccc_arch_workaround_1(void *data)
{
const struct arm64_cpu_capabilities *entry = data;
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 0;
@@ -198,33 +207,15 @@ static int enable_smccc_arch_workaround_1(void *data)
return 0;
}
+ 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 0;
}
-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 int qcom_enable_link_stack_sanitization(void *data)
-{
- const struct arm64_cpu_capabilities *entry = data;
-
- install_bp_hardening_cb(entry, qcom_link_stack_sanitization,
- __qcom_hyp_sanitize_link_stack_start,
- __qcom_hyp_sanitize_link_stack_end);
-
- return 0;
-}
#endif /* CONFIG_HARDEN_BRANCH_PREDICTOR */
#define MIDR_RANGE(model, min, max) \
@@ -399,20 +390,12 @@ const struct arm64_cpu_capabilities arm64_errata[] = {
{
.capability = ARM64_HARDEN_BRANCH_PREDICTOR,
MIDR_ALL_VERSIONS(MIDR_QCOM_FALKOR_V1),
- .enable = qcom_enable_link_stack_sanitization,
- },
- {
- .capability = ARM64_HARDEN_BP_POST_GUEST_EXIT,
- MIDR_ALL_VERSIONS(MIDR_QCOM_FALKOR_V1),
+ .enable = enable_smccc_arch_workaround_1,
},
{
.capability = ARM64_HARDEN_BRANCH_PREDICTOR,
MIDR_ALL_VERSIONS(MIDR_QCOM_FALKOR),
- .enable = qcom_enable_link_stack_sanitization,
- },
- {
- .capability = ARM64_HARDEN_BP_POST_GUEST_EXIT,
- MIDR_ALL_VERSIONS(MIDR_QCOM_FALKOR),
+ .enable = enable_smccc_arch_workaround_1,
},
{
.capability = ARM64_HARDEN_BRANCH_PREDICTOR,
diff --git a/arch/arm64/kvm/hyp/entry.S b/arch/arm64/kvm/hyp/entry.S
index 1f458f7c3b44..e41a161d313a 100644
--- a/arch/arm64/kvm/hyp/entry.S
+++ b/arch/arm64/kvm/hyp/entry.S
@@ -209,15 +209,3 @@ 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)
diff --git a/arch/arm64/kvm/hyp/switch.c b/arch/arm64/kvm/hyp/switch.c
index 07b572173265..d9645236e474 100644
--- a/arch/arm64/kvm/hyp/switch.c
+++ b/arch/arm64/kvm/hyp/switch.c
@@ -472,16 +472,6 @@ int __hyp_text __kvm_vcpu_run_nvhe(struct kvm_vcpu *vcpu)
/* And we're baaack! */
} while (fixup_guest_exit(vcpu, &exit_code));
- 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_nvhe();
__sysreg_save_state_nvhe(guest_ctxt);