diff options
Diffstat (limited to 'lib')
| -rw-r--r-- | lib/cpus/aarch64/workaround_cve_2017_5715_bpiall.S | 223 | ||||
| -rw-r--r-- | lib/cpus/aarch64/workaround_cve_2017_5715_mmu.S | 62 | ||||
| -rw-r--r-- | lib/psci/psci_main.c | 6 |
3 files changed, 157 insertions, 134 deletions
diff --git a/lib/cpus/aarch64/workaround_cve_2017_5715_bpiall.S b/lib/cpus/aarch64/workaround_cve_2017_5715_bpiall.S index cd29266e..cd824973 100644 --- a/lib/cpus/aarch64/workaround_cve_2017_5715_bpiall.S +++ b/lib/cpus/aarch64/workaround_cve_2017_5715_bpiall.S @@ -1,20 +1,27 @@ /* - * Copyright (c) 2017, ARM Limited and Contributors. All rights reserved. + * Copyright (c) 2017-2018, ARM Limited and Contributors. All rights reserved. * * SPDX-License-Identifier: BSD-3-Clause */ #include <arch.h> +#include <arm_arch_svc.h> #include <asm_macros.S> #include <context.h> .globl workaround_bpiall_vbar0_runtime_exceptions #define EMIT_BPIALL 0xee070fd5 -#define EMIT_MOV_R0_IMM(v) 0xe3a0000##v #define EMIT_SMC 0xe1600070 +#define ESR_EL3_A64_SMC0 0x5e000000 + + .macro enter_workaround _from_vector + /* + * Save register state to enable a call to AArch32 S-EL1 and return + * Identify the original calling vector in w2 (==_from_vector) + * Use w3-w6 for additional register state preservation while in S-EL1 + */ - .macro enter_workaround _stub_name /* Save GP regs */ stp x0, x1, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_X0] stp x2, x3, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_X2] @@ -32,47 +39,50 @@ stp x26, x27, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_X26] stp x28, x29, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_X28] - adr x4, \_stub_name + /* Identify the original exception vector */ + mov w2, \_from_vector + + /* Preserve 32-bit system registers in GP registers through the workaround */ + mrs x3, esr_el3 + mrs x4, spsr_el3 + mrs x5, scr_el3 + mrs x6, sctlr_el1 /* - * Load SPSR_EL3 and VBAR_EL3. SPSR_EL3 is set up to have - * all interrupts masked in preparation to running the workaround - * stub in S-EL1. VBAR_EL3 points to the vector table that - * will handle the SMC back from the workaround stub. + * Preserve LR and ELR_EL3 registers in the GP regs context. + * Temporarily use the CTX_GPREG_SP_EL0 slot to preserve ELR_EL3 + * through the workaround. This is OK because at this point the + * current state for this context's SP_EL0 is in the live system + * register, which is unmodified by the workaround. */ - ldp x0, x1, [x4, #0] + mrs x7, elr_el3 + stp x30, x7, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_LR] /* - * Load SCTLR_EL1 and ELR_EL3. SCTLR_EL1 is configured to disable - * the MMU in S-EL1. ELR_EL3 points to the appropriate stub in S-EL1. + * Load system registers for entry to S-EL1. */ - ldp x2, x3, [x4, #16] - mrs x4, scr_el3 - mrs x5, spsr_el3 - mrs x6, elr_el3 - mrs x7, sctlr_el1 - mrs x8, esr_el3 + /* Mask all interrupts and set AArch32 Supervisor mode */ + movz w8, SPSR_MODE32(MODE32_svc, SPSR_T_ARM, SPSR_E_LITTLE, SPSR_AIF_MASK) + + /* Switch EL3 exception vectors while the workaround is executing. */ + adr x9, workaround_bpiall_vbar1_runtime_exceptions + + /* Setup SCTLR_EL1 with MMU off and I$ on */ + ldr x10, stub_sel1_sctlr - /* Preserve system registers in the workaround context */ - stp x4, x5, [sp, #CTX_CVE_2017_5715_OFFSET + CTX_CVE_2017_5715_QUAD0] - stp x6, x7, [sp, #CTX_CVE_2017_5715_OFFSET + CTX_CVE_2017_5715_QUAD2] - stp x8, x30, [sp, #CTX_CVE_2017_5715_OFFSET + CTX_CVE_2017_5715_QUAD4] + /* Land at the S-EL1 workaround stub */ + adr x11, aarch32_stub /* * Setting SCR_EL3 to all zeroes means that the NS, RW * and SMD bits are configured as expected. */ msr scr_el3, xzr - - /* - * Reload system registers with the crafted values - * in preparation for entry in S-EL1. - */ - msr spsr_el3, x0 - msr vbar_el3, x1 - msr sctlr_el1, x2 - msr elr_el3, x3 + msr spsr_el3, x8 + msr vbar_el3, x9 + msr sctlr_el1, x10 + msr elr_el3, x11 eret .endm @@ -91,76 +101,31 @@ vector_base workaround_bpiall_vbar0_runtime_exceptions */ vector_entry workaround_bpiall_vbar0_sync_exception_sp_el0 b sync_exception_sp_el0 + nop /* to force 8 byte alignment for the following stub */ + /* * Since each vector table entry is 128 bytes, we can store the * stub context in the unused space to minimize memory footprint. */ -aarch32_stub_smc: +stub_sel1_sctlr: + .quad SCTLR_AARCH32_EL1_RES1 | SCTLR_I_BIT + +aarch32_stub: .word EMIT_BPIALL - .word EMIT_MOV_R0_IMM(1) .word EMIT_SMC -aarch32_stub_ctx_smc: - /* Mask all interrupts and set AArch32 Supervisor mode */ - .quad (SPSR_AIF_MASK << SPSR_AIF_SHIFT | \ - SPSR_M_AARCH32 << SPSR_M_SHIFT | \ - MODE32_svc << MODE32_SHIFT) - /* - * VBAR_EL3 points to vbar1 which is the vector table - * used while the workaround is executing. - */ - .quad workaround_bpiall_vbar1_runtime_exceptions - - /* Setup SCTLR_EL1 with MMU off and I$ on */ - .quad SCTLR_AARCH32_EL1_RES1 | SCTLR_I_BIT - - /* ELR_EL3 is setup to point to the sync exception stub in AArch32 */ - .quad aarch32_stub_smc check_vector_size workaround_bpiall_vbar0_sync_exception_sp_el0 vector_entry workaround_bpiall_vbar0_irq_sp_el0 b irq_sp_el0 -aarch32_stub_irq: - .word EMIT_BPIALL - .word EMIT_MOV_R0_IMM(2) - .word EMIT_SMC -aarch32_stub_ctx_irq: - .quad (SPSR_AIF_MASK << SPSR_AIF_SHIFT | \ - SPSR_M_AARCH32 << SPSR_M_SHIFT | \ - MODE32_svc << MODE32_SHIFT) - .quad workaround_bpiall_vbar1_runtime_exceptions - .quad SCTLR_AARCH32_EL1_RES1 | SCTLR_I_BIT - .quad aarch32_stub_irq check_vector_size workaround_bpiall_vbar0_irq_sp_el0 vector_entry workaround_bpiall_vbar0_fiq_sp_el0 b fiq_sp_el0 -aarch32_stub_fiq: - .word EMIT_BPIALL - .word EMIT_MOV_R0_IMM(4) - .word EMIT_SMC -aarch32_stub_ctx_fiq: - .quad (SPSR_AIF_MASK << SPSR_AIF_SHIFT | \ - SPSR_M_AARCH32 << SPSR_M_SHIFT | \ - MODE32_svc << MODE32_SHIFT) - .quad workaround_bpiall_vbar1_runtime_exceptions - .quad SCTLR_AARCH32_EL1_RES1 | SCTLR_I_BIT - .quad aarch32_stub_fiq check_vector_size workaround_bpiall_vbar0_fiq_sp_el0 vector_entry workaround_bpiall_vbar0_serror_sp_el0 b serror_sp_el0 -aarch32_stub_serror: - .word EMIT_BPIALL - .word EMIT_MOV_R0_IMM(8) - .word EMIT_SMC -aarch32_stub_ctx_serror: - .quad (SPSR_AIF_MASK << SPSR_AIF_SHIFT | \ - SPSR_M_AARCH32 << SPSR_M_SHIFT | \ - MODE32_svc << MODE32_SHIFT) - .quad workaround_bpiall_vbar1_runtime_exceptions - .quad SCTLR_AARCH32_EL1_RES1 | SCTLR_I_BIT - .quad aarch32_stub_serror check_vector_size workaround_bpiall_vbar0_serror_sp_el0 /* --------------------------------------------------------------------- @@ -188,19 +153,19 @@ vector_entry workaround_bpiall_vbar0_serror_sp_elx * --------------------------------------------------------------------- */ vector_entry workaround_bpiall_vbar0_sync_exception_aarch64 - enter_workaround aarch32_stub_ctx_smc + enter_workaround 1 check_vector_size workaround_bpiall_vbar0_sync_exception_aarch64 vector_entry workaround_bpiall_vbar0_irq_aarch64 - enter_workaround aarch32_stub_ctx_irq + enter_workaround 2 check_vector_size workaround_bpiall_vbar0_irq_aarch64 vector_entry workaround_bpiall_vbar0_fiq_aarch64 - enter_workaround aarch32_stub_ctx_fiq + enter_workaround 4 check_vector_size workaround_bpiall_vbar0_fiq_aarch64 vector_entry workaround_bpiall_vbar0_serror_aarch64 - enter_workaround aarch32_stub_ctx_serror + enter_workaround 8 check_vector_size workaround_bpiall_vbar0_serror_aarch64 /* --------------------------------------------------------------------- @@ -208,19 +173,19 @@ vector_entry workaround_bpiall_vbar0_serror_aarch64 * --------------------------------------------------------------------- */ vector_entry workaround_bpiall_vbar0_sync_exception_aarch32 - enter_workaround aarch32_stub_ctx_smc + enter_workaround 1 check_vector_size workaround_bpiall_vbar0_sync_exception_aarch32 vector_entry workaround_bpiall_vbar0_irq_aarch32 - enter_workaround aarch32_stub_ctx_irq + enter_workaround 2 check_vector_size workaround_bpiall_vbar0_irq_aarch32 vector_entry workaround_bpiall_vbar0_fiq_aarch32 - enter_workaround aarch32_stub_ctx_fiq + enter_workaround 4 check_vector_size workaround_bpiall_vbar0_fiq_aarch32 vector_entry workaround_bpiall_vbar0_serror_aarch32 - enter_workaround aarch32_stub_ctx_serror + enter_workaround 8 check_vector_size workaround_bpiall_vbar0_serror_aarch32 /* --------------------------------------------------------------------- @@ -297,31 +262,33 @@ vector_entry workaround_bpiall_vbar1_serror_aarch64 * --------------------------------------------------------------------- */ vector_entry workaround_bpiall_vbar1_sync_exception_aarch32 - /* Restore register state from the workaround context */ - ldp x2, x3, [sp, #CTX_CVE_2017_5715_OFFSET + CTX_CVE_2017_5715_QUAD0] - ldp x4, x5, [sp, #CTX_CVE_2017_5715_OFFSET + CTX_CVE_2017_5715_QUAD2] - ldp x6, x30, [sp, #CTX_CVE_2017_5715_OFFSET + CTX_CVE_2017_5715_QUAD4] + /* + * w2 indicates which SEL1 stub was run and thus which original vector was used + * w3-w6 contain saved system register state (esr_el3 in w3) + * Restore LR and ELR_EL3 register state from the GP regs context + */ + ldp x30, x7, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_LR] /* Apply the restored system register state */ - msr scr_el3, x2 - msr spsr_el3, x3 - msr elr_el3, x4 - msr sctlr_el1, x5 - msr esr_el3, x6 + msr esr_el3, x3 + msr spsr_el3, x4 + msr scr_el3, x5 + msr sctlr_el1, x6 + msr elr_el3, x7 /* * Workaround is complete, so swap VBAR_EL3 to point * to workaround entry table in preparation for subsequent * Sync/IRQ/FIQ/SError exceptions. */ - adr x2, workaround_bpiall_vbar0_runtime_exceptions - msr vbar_el3, x2 + adr x0, workaround_bpiall_vbar0_runtime_exceptions + msr vbar_el3, x0 /* - * Restore all GP regs except x0 and x1. The value in x0 + * Restore all GP regs except x2 and x3 (esr). The value in x2 * indicates the type of the original exception. */ - ldp x2, x3, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_X2] + ldp x0, x1, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_X0] ldp x4, x5, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_X4] ldp x6, x7, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_X6] ldp x8, x9, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_X8] @@ -336,37 +303,55 @@ vector_entry workaround_bpiall_vbar1_sync_exception_aarch32 ldp x26, x27, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_X26] ldp x28, x29, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_X28] + /* Fast path Sync exceptions. Static predictor will fall through. */ + tbz w2, #0, workaround_not_sync + /* - * Each of these handlers will first restore x0 and x1 from - * the context and the branch to the common implementation for - * each of the exception types. + * Check if SMC is coming from A64 state on #0 + * with W0 = SMCCC_ARCH_WORKAROUND_1 + * + * This sequence evaluates as: + * (W0==SMCCC_ARCH_WORKAROUND_1) ? (ESR_EL3==SMC#0) : (NE) + * allowing use of a single branch operation */ - tbnz x0, #1, workaround_bpiall_vbar1_irq - tbnz x0, #2, workaround_bpiall_vbar1_fiq - tbnz x0, #3, workaround_bpiall_vbar1_serror - - /* Fallthrough case for Sync exception */ - ldp x0, x1, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_X0] + orr w2, wzr, #SMCCC_ARCH_WORKAROUND_1 + cmp w0, w2 + mov_imm w2, ESR_EL3_A64_SMC0 + ccmp w3, w2, #0, eq + /* Static predictor will predict a fall through */ + bne 1f + eret +1: + ldp x2, x3, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_X2] b sync_exception_aarch64 check_vector_size workaround_bpiall_vbar1_sync_exception_aarch32 vector_entry workaround_bpiall_vbar1_irq_aarch32 b report_unhandled_interrupt -workaround_bpiall_vbar1_irq: - ldp x0, x1, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_X0] + + /* + * Post-workaround fan-out for non-sync exceptions + */ +workaround_not_sync: + tbnz w2, #3, workaround_bpiall_vbar1_serror + tbnz w2, #2, workaround_bpiall_vbar1_fiq + /* IRQ */ + ldp x2, x3, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_X2] b irq_aarch64 + +workaround_bpiall_vbar1_fiq: + ldp x2, x3, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_X2] + b fiq_aarch64 + +workaround_bpiall_vbar1_serror: + ldp x2, x3, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_X2] + b serror_aarch64 check_vector_size workaround_bpiall_vbar1_irq_aarch32 vector_entry workaround_bpiall_vbar1_fiq_aarch32 b report_unhandled_interrupt -workaround_bpiall_vbar1_fiq: - ldp x0, x1, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_X0] - b fiq_aarch64 check_vector_size workaround_bpiall_vbar1_fiq_aarch32 vector_entry workaround_bpiall_vbar1_serror_aarch32 b report_unhandled_exception -workaround_bpiall_vbar1_serror: - ldp x0, x1, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_X0] - b serror_aarch64 check_vector_size workaround_bpiall_vbar1_serror_aarch32 diff --git a/lib/cpus/aarch64/workaround_cve_2017_5715_mmu.S b/lib/cpus/aarch64/workaround_cve_2017_5715_mmu.S index f4781484..b24b620c 100644 --- a/lib/cpus/aarch64/workaround_cve_2017_5715_mmu.S +++ b/lib/cpus/aarch64/workaround_cve_2017_5715_mmu.S @@ -1,26 +1,60 @@ /* - * Copyright (c) 2017, ARM Limited and Contributors. All rights reserved. + * Copyright (c) 2017-2018, ARM Limited and Contributors. All rights reserved. * * SPDX-License-Identifier: BSD-3-Clause */ #include <arch.h> +#include <arm_arch_svc.h> #include <asm_macros.S> #include <context.h> .globl workaround_mmu_runtime_exceptions +#define ESR_EL3_A64_SMC0 0x5e000000 + vector_base workaround_mmu_runtime_exceptions - .macro apply_workaround + .macro apply_workaround _is_sync_exception stp x0, x1, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_X0] - mrs x0, sctlr_el3 + mrs x1, sctlr_el3 /* Disable MMU */ - bic x1, x0, #SCTLR_M_BIT + bic x1, x1, #SCTLR_M_BIT msr sctlr_el3, x1 isb - /* Restore MMU config */ - msr sctlr_el3, x0 + /* Enable MMU */ + orr x1, x1, #SCTLR_M_BIT + msr sctlr_el3, x1 + /* + * Defer ISB to avoid synchronizing twice in case we hit + * the workaround SMC call which will implicitly synchronize + * because of the ERET instruction. + */ + + /* + * Ensure SMC is coming from A64 state on #0 + * with W0 = SMCCC_ARCH_WORKAROUND_1 + * + * This sequence evaluates as: + * (W0==SMCCC_ARCH_WORKAROUND_1) ? (ESR_EL3==SMC#0) : (NE) + * allowing use of a single branch operation + */ + .if \_is_sync_exception + orr w1, wzr, #SMCCC_ARCH_WORKAROUND_1 + cmp w0, w1 + mrs x0, esr_el3 + mov_imm w1, ESR_EL3_A64_SMC0 + ccmp w0, w1, #0, eq + /* Static predictor will predict a fall through */ + bne 1f + eret +1: + .endif + + /* + * Synchronize now to enable the MMU. This is required + * to ensure the load pair below reads the data stored earlier. + */ isb ldp x0, x1, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_X0] .endm @@ -70,22 +104,22 @@ vector_entry workaround_mmu_serror_sp_elx * --------------------------------------------------------------------- */ vector_entry workaround_mmu_sync_exception_aarch64 - apply_workaround + apply_workaround _is_sync_exception=1 b sync_exception_aarch64 check_vector_size workaround_mmu_sync_exception_aarch64 vector_entry workaround_mmu_irq_aarch64 - apply_workaround + apply_workaround _is_sync_exception=0 b irq_aarch64 check_vector_size workaround_mmu_irq_aarch64 vector_entry workaround_mmu_fiq_aarch64 - apply_workaround + apply_workaround _is_sync_exception=0 b fiq_aarch64 check_vector_size workaround_mmu_fiq_aarch64 vector_entry workaround_mmu_serror_aarch64 - apply_workaround + apply_workaround _is_sync_exception=0 b serror_aarch64 check_vector_size workaround_mmu_serror_aarch64 @@ -94,21 +128,21 @@ vector_entry workaround_mmu_serror_aarch64 * --------------------------------------------------------------------- */ vector_entry workaround_mmu_sync_exception_aarch32 - apply_workaround + apply_workaround _is_sync_exception=1 b sync_exception_aarch32 check_vector_size workaround_mmu_sync_exception_aarch32 vector_entry workaround_mmu_irq_aarch32 - apply_workaround + apply_workaround _is_sync_exception=0 b irq_aarch32 check_vector_size workaround_mmu_irq_aarch32 vector_entry workaround_mmu_fiq_aarch32 - apply_workaround + apply_workaround _is_sync_exception=0 b fiq_aarch32 check_vector_size workaround_mmu_fiq_aarch32 vector_entry workaround_mmu_serror_aarch32 - apply_workaround + apply_workaround _is_sync_exception=0 b serror_aarch32 check_vector_size workaround_mmu_serror_aarch32 diff --git a/lib/psci/psci_main.c b/lib/psci/psci_main.c index 8e41cf02..88cf5cbe 100644 --- a/lib/psci/psci_main.c +++ b/lib/psci/psci_main.c @@ -1,11 +1,12 @@ /* - * Copyright (c) 2013-2017, ARM Limited and Contributors. All rights reserved. + * Copyright (c) 2013-2018, ARM Limited and Contributors. All rights reserved. * * SPDX-License-Identifier: BSD-3-Clause */ #include <arch.h> #include <arch_helpers.h> +#include <arm_arch_svc.h> #include <assert.h> #include <debug.h> #include <platform.h> @@ -322,6 +323,9 @@ int psci_features(unsigned int psci_fid) { unsigned int local_caps = psci_caps; + if (psci_fid == SMCCC_VERSION) + return PSCI_E_SUCCESS; + /* Check if it is a 64 bit function */ if (((psci_fid >> FUNCID_CC_SHIFT) & FUNCID_CC_MASK) == SMC_64) local_caps &= PSCI_CAP_64BIT_MASK; |