Merge "fix(sdei): set SPSR for SDEI based on TakeException" into integration

This commit is contained in:
Manish Pandey 2021-07-26 11:15:30 +02:00 committed by TrustedFirmware Code Review
commit f98c0bea9c
3 changed files with 102 additions and 13 deletions

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@ -263,6 +263,9 @@
#define ID_AA64MMFR1_EL1_PAN2_SUPPORTED ULL(0x2)
#define ID_AA64MMFR1_EL1_PAN3_SUPPORTED ULL(0x3)
#define ID_AA64MMFR1_EL1_VHE_SHIFT U(8)
#define ID_AA64MMFR1_EL1_VHE_MASK ULL(0xf)
/* ID_AA64MMFR2_EL1 definitions */
#define ID_AA64MMFR2_EL1 S3_0_C0_C7_2
@ -390,7 +393,8 @@
#define SCTLR_ATA0_BIT (ULL(1) << 42)
#define SCTLR_ATA_BIT (ULL(1) << 43)
#define SCTLR_DSSBS_BIT (ULL(1) << 44)
#define SCTLR_DSSBS_SHIFT U(44)
#define SCTLR_DSSBS_BIT (ULL(1) << SCTLR_DSSBS_SHIFT)
#define SCTLR_TWEDEn_BIT (ULL(1) << 45)
#define SCTLR_TWEDEL_SHIFT U(46)
#define SCTLR_TWEDEL_MASK ULL(0xf)
@ -570,8 +574,16 @@
#define SPSR_EL_SHIFT U(2)
#define SPSR_EL_WIDTH U(2)
#define SPSR_SSBS_BIT_AARCH64 BIT_64(12)
#define SPSR_SSBS_BIT_AARCH32 BIT_64(23)
#define SPSR_SSBS_SHIFT_AARCH64 U(12)
#define SPSR_SSBS_BIT_AARCH64 (ULL(1) << SPSR_SSBS_SHIFT_AARCH64)
#define SPSR_SSBS_SHIFT_AARCH32 U(23)
#define SPSR_SSBS_BIT_AARCH32 (ULL(1) << SPSR_SSBS_SHIFT_AARCH32)
#define SPSR_PAN_BIT BIT_64(22)
#define SPSR_DIT_BIT BIT(24)
#define SPSR_TCO_BIT_AARCH64 BIT_64(25)
#define DISABLE_ALL_EXCEPTIONS \
(DAIF_FIQ_BIT | DAIF_IRQ_BIT | DAIF_ABT_BIT | DAIF_DBG_BIT)

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@ -17,6 +17,18 @@ static inline bool is_armv7_gentimer_present(void)
return true;
}
static inline bool is_armv8_1_pan_present(void)
{
return ((read_id_aa64mmfr1_el1() >> ID_AA64MMFR1_EL1_PAN_SHIFT) &
ID_AA64MMFR1_EL1_PAN_MASK) != 0U;
}
static inline bool is_armv8_1_vhe_present(void)
{
return ((read_id_aa64mmfr1_el1() >> ID_AA64MMFR1_EL1_VHE_SHIFT) &
ID_AA64MMFR1_EL1_VHE_MASK) != 0U;
}
static inline bool is_armv8_2_ttcnp_present(void)
{
return ((read_id_aa64mmfr2_el1() >> ID_AA64MMFR2_EL1_CNP_SHIFT) &

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@ -1,5 +1,5 @@
/*
* Copyright (c) 2017-2019, ARM Limited and Contributors. All rights reserved.
* Copyright (c) 2017-2021, ARM Limited and Contributors. All rights reserved.
*
* SPDX-License-Identifier: BSD-3-Clause
*/
@ -8,6 +8,7 @@
#include <string.h>
#include <arch_helpers.h>
#include <arch_features.h>
#include <bl31/ehf.h>
#include <bl31/interrupt_mgmt.h>
#include <common/bl_common.h>
@ -231,6 +232,77 @@ static cpu_context_t *restore_and_resume_ns_context(void)
return ns_ctx;
}
/*
* Prepare for ERET:
* - Set the ELR to the registered handler address
* - Set the SPSR register as described in the SDEI documentation and
* the AArch64.TakeException() pseudocode function in
* ARM DDI 0487F.c page J1-7635
*/
static void sdei_set_elr_spsr(sdei_entry_t *se, sdei_dispatch_context_t *disp_ctx)
{
unsigned int client_el = sdei_client_el();
u_register_t sdei_spsr = SPSR_64(client_el, MODE_SP_ELX,
DISABLE_ALL_EXCEPTIONS);
u_register_t interrupted_pstate = disp_ctx->spsr_el3;
/* Check the SPAN bit in the client el SCTLR */
u_register_t client_el_sctlr;
if (client_el == MODE_EL2) {
client_el_sctlr = read_sctlr_el2();
} else {
client_el_sctlr = read_sctlr_el1();
}
/*
* Check whether to force the PAN bit or use the value in the
* interrupted EL according to the check described in
* TakeException. Since the client can only be Non-Secure
* EL2 or El1 some of the conditions in ElIsInHost() we know
* will always be True.
* When the client_el is EL2 we know that there will be a SPAN
* bit in SCTLR_EL2 as we have already checked for the condition
* HCR_EL2.E2H = 1 and HCR_EL2.TGE = 1
*/
u_register_t hcr_el2 = read_hcr();
bool el_is_in_host = is_armv8_1_vhe_present() &&
(hcr_el2 & HCR_TGE_BIT) &&
(hcr_el2 & HCR_E2H_BIT);
if (is_armv8_1_pan_present() &&
((client_el == MODE_EL1) ||
(client_el == MODE_EL2 && el_is_in_host)) &&
((client_el_sctlr & SCTLR_SPAN_BIT) == 0U)) {
sdei_spsr |= SPSR_PAN_BIT;
} else {
sdei_spsr |= (interrupted_pstate & SPSR_PAN_BIT);
}
/* If SSBS is implemented, take the value from the client el SCTLR */
u_register_t ssbs_enabled = (read_id_aa64pfr1_el1()
>> ID_AA64PFR1_EL1_SSBS_SHIFT)
& ID_AA64PFR1_EL1_SSBS_MASK;
if (ssbs_enabled != SSBS_UNAVAILABLE) {
u_register_t ssbs_bit = ((client_el_sctlr & SCTLR_DSSBS_BIT)
>> SCTLR_DSSBS_SHIFT)
<< SPSR_SSBS_SHIFT_AARCH64;
sdei_spsr |= ssbs_bit;
}
/* If MTE is implemented in the client el set the TCO bit */
if (get_armv8_5_mte_support() >= MTE_IMPLEMENTED_ELX) {
sdei_spsr |= SPSR_TCO_BIT_AARCH64;
}
/* Take the DIT field from the pstate of the interrupted el */
sdei_spsr |= (interrupted_pstate & SPSR_DIT_BIT);
cm_set_elr_spsr_el3(NON_SECURE, (uintptr_t) se->ep, sdei_spsr);
}
/*
* Populate the Non-secure context so that the next ERET will dispatch to the
* SDEI client.
@ -256,15 +328,8 @@ static void setup_ns_dispatch(sdei_ev_map_t *map, sdei_entry_t *se,
SMC_SET_GP(ctx, CTX_GPREG_X2, disp_ctx->elr_el3);
SMC_SET_GP(ctx, CTX_GPREG_X3, disp_ctx->spsr_el3);
/*
* Prepare for ERET:
*
* - Set PC to the registered handler address
* - Set SPSR to jump to client EL with exceptions masked
*/
cm_set_elr_spsr_el3(NON_SECURE, (uintptr_t) se->ep,
SPSR_64(sdei_client_el(), MODE_SP_ELX,
DISABLE_ALL_EXCEPTIONS));
/* Setup the elr and spsr register to prepare for ERET */
sdei_set_elr_spsr(se, disp_ctx);
#if DYNAMIC_WORKAROUND_CVE_2018_3639
cve_2018_3639_t *tgt_cve_2018_3639;