| /* |
| * Copyright (c) 2017-2018, ARM Limited and Contributors. All rights reserved. |
| * |
| * SPDX-License-Identifier: BSD-3-Clause |
| */ |
| |
| #include <arch.h> |
| #include <asm_macros.S> |
| #include <context.h> |
| #include <services/arm_arch_svc.h> |
| |
| .globl wa_cve_2017_5715_bpiall_vbar |
| |
| #define EMIT_BPIALL 0xee070fd5 |
| #define EMIT_SMC 0xe1600070 |
| #define ESR_EL3_A64_SMC0 0x5e000000 |
| |
| .macro apply_cve_2017_5715_wa _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 |
| */ |
| |
| /* Save GP regs */ |
| stp x0, x1, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_X0] |
| stp x2, x3, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_X2] |
| stp x4, x5, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_X4] |
| stp x6, x7, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_X6] |
| stp x8, x9, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_X8] |
| stp x10, x11, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_X10] |
| stp x12, x13, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_X12] |
| stp x14, x15, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_X14] |
| stp x16, x17, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_X16] |
| stp x18, x19, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_X18] |
| stp x20, x21, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_X20] |
| stp x22, x23, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_X22] |
| stp x24, x25, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_X24] |
| stp x26, x27, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_X26] |
| stp x28, x29, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_X28] |
| |
| /* 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 |
| |
| /* |
| * 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. |
| */ |
| mrs x7, elr_el3 |
| stp x30, x7, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_LR] |
| |
| /* |
| * Load system registers for entry to S-EL1. |
| */ |
| |
| /* 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, wa_cve_2017_5715_bpiall_ret_vbar |
| |
| /* Setup SCTLR_EL1 with MMU off and I$ on */ |
| ldr x10, stub_sel1_sctlr |
| |
| /* 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 |
| msr spsr_el3, x8 |
| msr vbar_el3, x9 |
| msr sctlr_el1, x10 |
| msr elr_el3, x11 |
| |
| eret |
| .endm |
| |
| /* --------------------------------------------------------------------- |
| * This vector table is used at runtime to enter the workaround at |
| * AArch32 S-EL1 for Sync/IRQ/FIQ/SError exceptions. If the workaround |
| * is not enabled, the existing runtime exception vector table is used. |
| * --------------------------------------------------------------------- |
| */ |
| vector_base wa_cve_2017_5715_bpiall_vbar |
| |
| /* --------------------------------------------------------------------- |
| * Current EL with SP_EL0 : 0x0 - 0x200 |
| * --------------------------------------------------------------------- |
| */ |
| vector_entry bpiall_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. |
| */ |
| stub_sel1_sctlr: |
| .quad SCTLR_AARCH32_EL1_RES1 | SCTLR_I_BIT |
| |
| aarch32_stub: |
| .word EMIT_BPIALL |
| .word EMIT_SMC |
| |
| end_vector_entry bpiall_sync_exception_sp_el0 |
| |
| vector_entry bpiall_irq_sp_el0 |
| b irq_sp_el0 |
| end_vector_entry bpiall_irq_sp_el0 |
| |
| vector_entry bpiall_fiq_sp_el0 |
| b fiq_sp_el0 |
| end_vector_entry bpiall_fiq_sp_el0 |
| |
| vector_entry bpiall_serror_sp_el0 |
| b serror_sp_el0 |
| end_vector_entry bpiall_serror_sp_el0 |
| |
| /* --------------------------------------------------------------------- |
| * Current EL with SP_ELx: 0x200 - 0x400 |
| * --------------------------------------------------------------------- |
| */ |
| vector_entry bpiall_sync_exception_sp_elx |
| b sync_exception_sp_elx |
| end_vector_entry bpiall_sync_exception_sp_elx |
| |
| vector_entry bpiall_irq_sp_elx |
| b irq_sp_elx |
| end_vector_entry bpiall_irq_sp_elx |
| |
| vector_entry bpiall_fiq_sp_elx |
| b fiq_sp_elx |
| end_vector_entry bpiall_fiq_sp_elx |
| |
| vector_entry bpiall_serror_sp_elx |
| b serror_sp_elx |
| end_vector_entry bpiall_serror_sp_elx |
| |
| /* --------------------------------------------------------------------- |
| * Lower EL using AArch64 : 0x400 - 0x600 |
| * --------------------------------------------------------------------- |
| */ |
| vector_entry bpiall_sync_exception_aarch64 |
| apply_cve_2017_5715_wa 1 |
| end_vector_entry bpiall_sync_exception_aarch64 |
| |
| vector_entry bpiall_irq_aarch64 |
| apply_cve_2017_5715_wa 2 |
| end_vector_entry bpiall_irq_aarch64 |
| |
| vector_entry bpiall_fiq_aarch64 |
| apply_cve_2017_5715_wa 4 |
| end_vector_entry bpiall_fiq_aarch64 |
| |
| vector_entry bpiall_serror_aarch64 |
| apply_cve_2017_5715_wa 8 |
| end_vector_entry bpiall_serror_aarch64 |
| |
| /* --------------------------------------------------------------------- |
| * Lower EL using AArch32 : 0x600 - 0x800 |
| * --------------------------------------------------------------------- |
| */ |
| vector_entry bpiall_sync_exception_aarch32 |
| apply_cve_2017_5715_wa 1 |
| end_vector_entry bpiall_sync_exception_aarch32 |
| |
| vector_entry bpiall_irq_aarch32 |
| apply_cve_2017_5715_wa 2 |
| end_vector_entry bpiall_irq_aarch32 |
| |
| vector_entry bpiall_fiq_aarch32 |
| apply_cve_2017_5715_wa 4 |
| end_vector_entry bpiall_fiq_aarch32 |
| |
| vector_entry bpiall_serror_aarch32 |
| apply_cve_2017_5715_wa 8 |
| end_vector_entry bpiall_serror_aarch32 |
| |
| /* --------------------------------------------------------------------- |
| * This vector table is used while the workaround is executing. It |
| * installs a simple SMC handler to allow the Sync/IRQ/FIQ/SError |
| * workaround stubs to enter EL3 from S-EL1. It restores the previous |
| * EL3 state before proceeding with the normal runtime exception vector. |
| * --------------------------------------------------------------------- |
| */ |
| vector_base wa_cve_2017_5715_bpiall_ret_vbar |
| |
| /* --------------------------------------------------------------------- |
| * Current EL with SP_EL0 : 0x0 - 0x200 (UNUSED) |
| * --------------------------------------------------------------------- |
| */ |
| vector_entry bpiall_ret_sync_exception_sp_el0 |
| b report_unhandled_exception |
| end_vector_entry bpiall_ret_sync_exception_sp_el0 |
| |
| vector_entry bpiall_ret_irq_sp_el0 |
| b report_unhandled_interrupt |
| end_vector_entry bpiall_ret_irq_sp_el0 |
| |
| vector_entry bpiall_ret_fiq_sp_el0 |
| b report_unhandled_interrupt |
| end_vector_entry bpiall_ret_fiq_sp_el0 |
| |
| vector_entry bpiall_ret_serror_sp_el0 |
| b report_unhandled_exception |
| end_vector_entry bpiall_ret_serror_sp_el0 |
| |
| /* --------------------------------------------------------------------- |
| * Current EL with SP_ELx: 0x200 - 0x400 (UNUSED) |
| * --------------------------------------------------------------------- |
| */ |
| vector_entry bpiall_ret_sync_exception_sp_elx |
| b report_unhandled_exception |
| end_vector_entry bpiall_ret_sync_exception_sp_elx |
| |
| vector_entry bpiall_ret_irq_sp_elx |
| b report_unhandled_interrupt |
| end_vector_entry bpiall_ret_irq_sp_elx |
| |
| vector_entry bpiall_ret_fiq_sp_elx |
| b report_unhandled_interrupt |
| end_vector_entry bpiall_ret_fiq_sp_elx |
| |
| vector_entry bpiall_ret_serror_sp_elx |
| b report_unhandled_exception |
| end_vector_entry bpiall_ret_serror_sp_elx |
| |
| /* --------------------------------------------------------------------- |
| * Lower EL using AArch64 : 0x400 - 0x600 (UNUSED) |
| * --------------------------------------------------------------------- |
| */ |
| vector_entry bpiall_ret_sync_exception_aarch64 |
| b report_unhandled_exception |
| end_vector_entry bpiall_ret_sync_exception_aarch64 |
| |
| vector_entry bpiall_ret_irq_aarch64 |
| b report_unhandled_interrupt |
| end_vector_entry bpiall_ret_irq_aarch64 |
| |
| vector_entry bpiall_ret_fiq_aarch64 |
| b report_unhandled_interrupt |
| end_vector_entry bpiall_ret_fiq_aarch64 |
| |
| vector_entry bpiall_ret_serror_aarch64 |
| b report_unhandled_exception |
| end_vector_entry bpiall_ret_serror_aarch64 |
| |
| /* --------------------------------------------------------------------- |
| * Lower EL using AArch32 : 0x600 - 0x800 |
| * --------------------------------------------------------------------- |
| */ |
| vector_entry bpiall_ret_sync_exception_aarch32 |
| /* |
| * 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 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 x0, wa_cve_2017_5715_bpiall_vbar |
| msr vbar_el3, x0 |
| |
| /* |
| * Restore all GP regs except x2 and x3 (esr). The value in x2 |
| * indicates the type of the original exception. |
| */ |
| 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] |
| ldp x10, x11, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_X10] |
| ldp x12, x13, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_X12] |
| ldp x14, x15, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_X14] |
| ldp x16, x17, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_X16] |
| ldp x18, x19, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_X18] |
| ldp x20, x21, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_X20] |
| ldp x22, x23, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_X22] |
| ldp x24, x25, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_X24] |
| 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 |
| |
| /* |
| * 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 |
| */ |
| 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 |
| end_vector_entry bpiall_ret_sync_exception_aarch32 |
| |
| vector_entry bpiall_ret_irq_aarch32 |
| b report_unhandled_interrupt |
| |
| /* |
| * Post-workaround fan-out for non-sync exceptions |
| */ |
| workaround_not_sync: |
| tbnz w2, #3, bpiall_ret_serror |
| tbnz w2, #2, bpiall_ret_fiq |
| /* IRQ */ |
| ldp x2, x3, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_X2] |
| b irq_aarch64 |
| |
| bpiall_ret_fiq: |
| ldp x2, x3, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_X2] |
| b fiq_aarch64 |
| |
| bpiall_ret_serror: |
| ldp x2, x3, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_X2] |
| b serror_aarch64 |
| end_vector_entry bpiall_ret_irq_aarch32 |
| |
| vector_entry bpiall_ret_fiq_aarch32 |
| b report_unhandled_interrupt |
| end_vector_entry bpiall_ret_fiq_aarch32 |
| |
| vector_entry bpiall_ret_serror_aarch32 |
| b report_unhandled_exception |
| end_vector_entry bpiall_ret_serror_aarch32 |
