From: Marc Zyngier marc.zyngier@arm.com
commit b092201e0020614127f495c092e0a12d26a2116e upstream.
Add the detection and runtime code for ARM_SMCCC_ARCH_WORKAROUND_1. It is lovely. Really.
Tested-by: Ard Biesheuvel ard.biesheuvel@linaro.org Signed-off-by: Marc Zyngier marc.zyngier@arm.com Signed-off-by: Catalin Marinas catalin.marinas@arm.com Signed-off-by: Viresh Kumar viresh.kumar@linaro.org --- arch/arm64/kernel/bpi.S | 20 ++++++++++ arch/arm64/kernel/cpu_errata.c | 68 +++++++++++++++++++++++++++++++++- 2 files changed, 87 insertions(+), 1 deletion(-)
diff --git a/arch/arm64/kernel/bpi.S b/arch/arm64/kernel/bpi.S index dec95bd82e31..c72f261f4b64 100644 --- a/arch/arm64/kernel/bpi.S +++ b/arch/arm64/kernel/bpi.S @@ -17,6 +17,7 @@ */
#include <linux/linkage.h> +#include <linux/arm-smccc.h>
.macro ventry target .rept 31 @@ -77,3 +78,22 @@ ENTRY(__psci_hyp_bp_inval_start) ldp x0, x1, [sp, #(16 * 8)] add sp, sp, #(8 * 18) ENTRY(__psci_hyp_bp_inval_end) + +.macro smccc_workaround_1 inst + sub sp, sp, #(8 * 4) + stp x2, x3, [sp, #(8 * 0)] + stp x0, x1, [sp, #(8 * 2)] + mov w0, #ARM_SMCCC_ARCH_WORKAROUND_1 + \inst #0 + ldp x2, x3, [sp, #(8 * 0)] + ldp x0, x1, [sp, #(8 * 2)] + add sp, sp, #(8 * 4) +.endm + +ENTRY(__smccc_workaround_1_smc_start) + smccc_workaround_1 smc +ENTRY(__smccc_workaround_1_smc_end) + +ENTRY(__smccc_workaround_1_hvc_start) + smccc_workaround_1 hvc +ENTRY(__smccc_workaround_1_hvc_end) diff --git a/arch/arm64/kernel/cpu_errata.c b/arch/arm64/kernel/cpu_errata.c index ff22915a2865..d5fd7be563bc 100644 --- a/arch/arm64/kernel/cpu_errata.c +++ b/arch/arm64/kernel/cpu_errata.c @@ -51,6 +51,10 @@ DEFINE_PER_CPU_READ_MOSTLY(struct bp_hardening_data, bp_hardening_data);
#ifdef CONFIG_KVM extern char __psci_hyp_bp_inval_start[], __psci_hyp_bp_inval_end[]; +extern char __smccc_workaround_1_smc_start[]; +extern char __smccc_workaround_1_smc_end[]; +extern char __smccc_workaround_1_hvc_start[]; +extern char __smccc_workaround_1_hvc_end[];
static void __copy_hyp_vect_bpi(int slot, const char *hyp_vecs_start, const char *hyp_vecs_end) @@ -95,6 +99,10 @@ static void __install_bp_hardening_cb(bp_hardening_cb_t fn, #else #define __psci_hyp_bp_inval_start NULL #define __psci_hyp_bp_inval_end NULL +#define __smccc_workaround_1_smc_start NULL +#define __smccc_workaround_1_smc_end NULL +#define __smccc_workaround_1_hvc_start NULL +#define __smccc_workaround_1_hvc_end NULL
static void __install_bp_hardening_cb(bp_hardening_cb_t fn, const char *hyp_vecs_start, @@ -121,17 +129,75 @@ static void install_bp_hardening_cb(const struct arm64_cpu_capabilities *entry, __install_bp_hardening_cb(fn, hyp_vecs_start, hyp_vecs_end); }
+#include <uapi/linux/psci.h> +#include <linux/arm-smccc.h> #include <linux/psci.h>
+static void call_smc_arch_workaround_1(void) +{ + arm_smccc_1_1_smc(ARM_SMCCC_ARCH_WORKAROUND_1, NULL); +} + +static void call_hvc_arch_workaround_1(void) +{ + arm_smccc_1_1_hvc(ARM_SMCCC_ARCH_WORKAROUND_1, NULL); +} + +static bool check_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; + + if (!entry->matches(entry, SCOPE_LOCAL_CPU)) + return false; + + if (psci_ops.smccc_version == SMCCC_VERSION_1_0) + return false; + + switch (psci_ops.conduit) { + case PSCI_CONDUIT_HVC: + arm_smccc_1_1_hvc(ARM_SMCCC_ARCH_FEATURES_FUNC_ID, + ARM_SMCCC_ARCH_WORKAROUND_1, &res); + if (res.a0) + return false; + cb = call_hvc_arch_workaround_1; + smccc_start = __smccc_workaround_1_hvc_start; + smccc_end = __smccc_workaround_1_hvc_end; + break; + + case PSCI_CONDUIT_SMC: + arm_smccc_1_1_smc(ARM_SMCCC_ARCH_FEATURES_FUNC_ID, + ARM_SMCCC_ARCH_WORKAROUND_1, &res); + if (res.a0) + return false; + cb = call_smc_arch_workaround_1; + smccc_start = __smccc_workaround_1_smc_start; + smccc_end = __smccc_workaround_1_smc_end; + break; + + default: + return false; + } + + install_bp_hardening_cb(entry, cb, smccc_start, smccc_end); + + return true; +} + static int enable_psci_bp_hardening(void *data) { const struct arm64_cpu_capabilities *entry = data;
- if (psci_ops.get_version) + if (psci_ops.get_version) { + if (check_smccc_arch_workaround_1(entry)) + return 0; + install_bp_hardening_cb(entry, (bp_hardening_cb_t)psci_ops.get_version, __psci_hyp_bp_inval_start, __psci_hyp_bp_inval_end); + }
return 0; }