Apply stricter speculative load restriction

The SCTLR.DSSBS bit is zero by default thus disabling speculative loads.
However, we also explicitly set it to zero for BL2 and TSP images when
each image initialises its context. This is done to ensure that the
image environment is initialised in a safe state, regardless of the
reset value of the bit.

Change-Id: If25a8396641edb640f7f298b8d3309d5cba3cd79
Signed-off-by: John Tsichritzis <john.tsichritzis@arm.com>
This commit is contained in:
John Tsichritzis 2019-03-04 16:42:54 +00:00
parent c48d02bade
commit 02b5794396
5 changed files with 19 additions and 11 deletions

View File

@ -42,12 +42,13 @@ func bl2_entrypoint
stcopr r0, VBAR
isb
/* -----------------------------------------------------
* Enable the instruction cache
* -----------------------------------------------------
/* --------------------------------------------------------
* Enable the instruction cache - disable speculative loads
* --------------------------------------------------------
*/
ldcopr r0, SCTLR
orr r0, r0, #SCTLR_I_BIT
bic r0, r0, #SCTLR_DSSBS_BIT
stcopr r0, SCTLR
isb

View File

@ -41,12 +41,14 @@ func bl2_entrypoint
/* ---------------------------------------------
* Enable the instruction cache, stack pointer
* and data access alignment checks
* and data access alignment checks and disable
* speculative loads.
* ---------------------------------------------
*/
mov x1, #(SCTLR_I_BIT | SCTLR_A_BIT | SCTLR_SA_BIT)
mrs x0, sctlr_el1
orr x0, x0, x1
bic x0, x0, #SCTLR_DSSBS_BIT
msr sctlr_el1, x0
isb

View File

@ -1,5 +1,5 @@
/*
* Copyright (c) 2016, ARM Limited and Contributors. All rights reserved.
* Copyright (c) 2016-2019, ARM Limited and Contributors. All rights reserved.
*
* SPDX-License-Identifier: BSD-3-Clause
*/
@ -41,12 +41,13 @@ func bl2u_entrypoint
stcopr r0, VBAR
isb
/* -----------------------------------------------------
* Enable the instruction cache
* -----------------------------------------------------
/* --------------------------------------------------------
* Enable the instruction cache - disable speculative loads
* --------------------------------------------------------
*/
ldcopr r0, SCTLR
orr r0, r0, #SCTLR_I_BIT
bic r0, r0, #SCTLR_DSSBS_BIT
stcopr r0, SCTLR
isb

View File

@ -1,5 +1,5 @@
/*
* Copyright (c) 2015-2017, ARM Limited and Contributors. All rights reserved.
* Copyright (c) 2015-2019, ARM Limited and Contributors. All rights reserved.
*
* SPDX-License-Identifier: BSD-3-Clause
*/
@ -38,12 +38,14 @@ func bl2u_entrypoint
/* ---------------------------------------------
* Enable the instruction cache, stack pointer
* and data access alignment checks
* and data access alignment checks and disable
* speculative loads.
* ---------------------------------------------
*/
mov x1, #(SCTLR_I_BIT | SCTLR_A_BIT | SCTLR_SA_BIT)
mrs x0, sctlr_el1
orr x0, x0, x1
bic x0, x0, #SCTLR_DSSBS_BIT
msr sctlr_el1, x0
isb

View File

@ -63,12 +63,14 @@ func tsp_entrypoint _align=3
/* ---------------------------------------------
* Enable the instruction cache, stack pointer
* and data access alignment checks
* and data access alignment checks and disable
* speculative loads.
* ---------------------------------------------
*/
mov x1, #(SCTLR_I_BIT | SCTLR_A_BIT | SCTLR_SA_BIT)
mrs x0, sctlr_el1
orr x0, x0, x1
bic x0, x0, #SCTLR_DSSBS_BIT
msr sctlr_el1, x0
isb