fix(cpus): workaround for CVE-2024-5660 for Cortex-X4
Implements mitigation for CVE-2024-5660 that affects Cortex-X4
revisions r0p0, r0p1, r0p2.
The workaround is to disable the hardware page aggregation at
EL3 by setting CPUECTLR_EL1[46] = 1'b1.
Public Documentation:
https://developer.arm.com/Arm%20Security%20Center/Arm%20CPU%20Vulnerability%20CVE-2024-5660
Change-Id: I378cb4978919cced03e7febc2ad431c572eac72d
Signed-off-by: Sona Mathew <sonarebecca.mathew@arm.com>
diff --git a/docs/design/cpu-specific-build-macros.rst b/docs/design/cpu-specific-build-macros.rst
index fda43dc..b5f5431 100644
--- a/docs/design/cpu-specific-build-macros.rst
+++ b/docs/design/cpu-specific-build-macros.rst
@@ -33,6 +33,11 @@
This build option should be set to 1 if the target platform contains at
least 1 CPU that requires this mitigation. Defaults to 1.
+- ``WORKAROUND_CVE_2024_5660``: Enables mitigation for `CVE-2024-5660`.
+ The fix is to disable hardware page aggregation by setting CPUECTLR_EL1[46]
+ in EL3 FW. This build option should be set to 1 if the target platform contains
+ at least 1 CPU that requires this mitigation. Defaults to 1.
+
.. _arm_cpu_macros_errata_workarounds:
CPU Errata Workarounds
diff --git a/lib/cpus/aarch64/cortex_x4.S b/lib/cpus/aarch64/cortex_x4.S
index 9b5e61b..2d24472 100644
--- a/lib/cpus/aarch64/cortex_x4.S
+++ b/lib/cpus/aarch64/cortex_x4.S
@@ -46,6 +46,13 @@
ret
check_erratum_custom_end cortex_x4, ERRATUM(2726228)
+/* Disable hardware page aggregation. Enables mitigation for `CVE-2024-5660` */
+workaround_reset_start cortex_x4, CVE(2024, 5660), WORKAROUND_CVE_2024_5660
+ sysreg_bit_set CORTEX_X4_CPUECTLR_EL1, BIT(46)
+workaround_reset_end cortex_x4, CVE(2024, 5660)
+
+check_erratum_ls cortex_x4, CVE(2024, 5660), CPU_REV(0, 2)
+
workaround_runtime_start cortex_x4, ERRATUM(2740089), ERRATA_X4_2740089
/* dsb before isb of power down sequence */
dsb sy
diff --git a/lib/cpus/cpu-ops.mk b/lib/cpus/cpu-ops.mk
index 4c20785..e1e0f47 100644
--- a/lib/cpus/cpu-ops.mk
+++ b/lib/cpus/cpu-ops.mk
@@ -7,6 +7,11 @@
include ${MAKE_HELPERS_DIRECTORY}$/build_macros.mk
+# Flag to disable Hardware page aggregation(HPA).
+# This flag is enabled by default.
+WORKAROUND_CVE_2024_5660 ?=1
+CPU_FLAG_LIST += WORKAROUND_CVE_2024_5660
+
# Cortex A57 specific optimisation to skip L1 cache flush when
# cluster is powered down.
CPU_FLAG_LIST += SKIP_A57_L1_FLUSH_PWR_DWN