fix(security): apply SMCCC_ARCH_WORKAROUND_4 to affected cpus
This patch implements SMCCC_ARCH_WORKAROUND_4 and
allows discovery through SMCCC_ARCH_FEATURES.
This mechanism is enabled if CVE_2024_7881 [1] is enabled
by the platform. If CVE_2024_7881 mitigation
is implemented, the discovery call returns 0,
if not -1 (SMC_ARCH_CALL_NOT_SUPPORTED).
For more information about SMCCC_ARCH_WORKAROUND_4 [2], please
refer to the SMCCC Specification reference provided below.
[1]: https://developer.arm.com/Arm%20Security%20Center/Arm%20CPU%20Vulnerability%20CVE-2024-7881
[2]: https://developer.arm.com/documentation/den0028/latest
Signed-off-by: Arvind Ram Prakash <arvind.ramprakash@arm.com>
Change-Id: I1b1ffaa1f806f07472fd79d5525f81764d99bc79
diff --git a/lib/cpus/aarch64/cortex_x3.S b/lib/cpus/aarch64/cortex_x3.S
index cbdfe3b..4a0212e 100644
--- a/lib/cpus/aarch64/cortex_x3.S
+++ b/lib/cpus/aarch64/cortex_x3.S
@@ -162,6 +162,10 @@
ret
endfunc cortex_x3_cpu_reg_dump
-declare_cpu_ops cortex_x3, CORTEX_X3_MIDR, \
+declare_cpu_ops_wa_4 cortex_x3, CORTEX_X3_MIDR, \
cortex_x3_reset_func, \
+ CPU_NO_EXTRA1_FUNC, \
+ CPU_NO_EXTRA2_FUNC, \
+ CPU_NO_EXTRA3_FUNC, \
+ check_erratum_cortex_x3_7881, \
cortex_x3_core_pwr_dwn
diff --git a/lib/cpus/aarch64/cortex_x4.S b/lib/cpus/aarch64/cortex_x4.S
index e733f41..5765828 100644
--- a/lib/cpus/aarch64/cortex_x4.S
+++ b/lib/cpus/aarch64/cortex_x4.S
@@ -160,6 +160,10 @@
ret
endfunc cortex_x4_cpu_reg_dump
-declare_cpu_ops cortex_x4, CORTEX_X4_MIDR, \
+declare_cpu_ops_wa_4 cortex_x4, CORTEX_X4_MIDR, \
cortex_x4_reset_func, \
+ CPU_NO_EXTRA1_FUNC, \
+ CPU_NO_EXTRA2_FUNC, \
+ CPU_NO_EXTRA3_FUNC, \
+ check_erratum_cortex_x4_7881, \
cortex_x4_core_pwr_dwn
diff --git a/lib/cpus/aarch64/cortex_x925.S b/lib/cpus/aarch64/cortex_x925.S
index c76c821..5b6632a 100644
--- a/lib/cpus/aarch64/cortex_x925.S
+++ b/lib/cpus/aarch64/cortex_x925.S
@@ -77,6 +77,10 @@
ret
endfunc cortex_x925_cpu_reg_dump
-declare_cpu_ops cortex_x925, CORTEX_X925_MIDR, \
+declare_cpu_ops_wa_4 cortex_x925, CORTEX_X925_MIDR, \
cortex_x925_reset_func, \
+ CPU_NO_EXTRA1_FUNC, \
+ CPU_NO_EXTRA2_FUNC, \
+ CPU_NO_EXTRA3_FUNC, \
+ check_erratum_cortex_x925_7881, \
cortex_x925_core_pwr_dwn
diff --git a/lib/cpus/aarch64/cpu_helpers.S b/lib/cpus/aarch64/cpu_helpers.S
index 3aa4f15..0f9a3b8 100644
--- a/lib/cpus/aarch64/cpu_helpers.S
+++ b/lib/cpus/aarch64/cpu_helpers.S
@@ -327,6 +327,43 @@
endfunc check_wa_cve_2017_5715
/*
+ * int check_wa_cve_2024_7881(void);
+ *
+ * This function returns:
+ * - ERRATA_APPLIES when firmware mitigation is required.
+ * - ERRATA_NOT_APPLIES when firmware mitigation is _not_ required.
+ * - ERRATA_MISSING when firmware mitigation would be required but
+ * is not compiled in.
+ *
+ * NOTE: Must be called only after cpu_ops have been initialized
+ * in per-CPU data.
+ */
+.globl check_wa_cve_2024_7881
+func check_wa_cve_2024_7881
+ mrs x0, tpidr_el3
+#if ENABLE_ASSERTIONS
+ cmp x0, #0
+ ASM_ASSERT(ne)
+#endif
+ ldr x0, [x0, #CPU_DATA_CPU_OPS_PTR]
+#if ENABLE_ASSERTIONS
+ cmp x0, #0
+ ASM_ASSERT(ne)
+#endif
+ ldr x0, [x0, #CPU_EXTRA4_FUNC]
+ /*
+ * If the reserved function pointer is NULL, this CPU
+ * is unaffected by CVE-2024-7881 so bail out.
+ */
+ cmp x0, #CPU_NO_EXTRA4_FUNC
+ beq 1f
+ br x0
+1:
+ mov x0, #ERRATA_NOT_APPLIES
+ ret
+endfunc check_wa_cve_2024_7881
+
+/*
* void *wa_cve_2018_3639_get_disable_ptr(void);
*
* Returns a function pointer which is used to disable mitigation
diff --git a/lib/cpus/aarch64/neoverse_v2.S b/lib/cpus/aarch64/neoverse_v2.S
index 56b5124..b43f6dd 100644
--- a/lib/cpus/aarch64/neoverse_v2.S
+++ b/lib/cpus/aarch64/neoverse_v2.S
@@ -153,6 +153,10 @@
ret
endfunc neoverse_v2_cpu_reg_dump
-declare_cpu_ops neoverse_v2, NEOVERSE_V2_MIDR, \
+declare_cpu_ops_wa_4 neoverse_v2, NEOVERSE_V2_MIDR, \
neoverse_v2_reset_func, \
+ CPU_NO_EXTRA1_FUNC, \
+ CPU_NO_EXTRA2_FUNC, \
+ CPU_NO_EXTRA3_FUNC, \
+ check_erratum_neoverse_v2_7881, \
neoverse_v2_core_pwr_dwn
diff --git a/lib/cpus/aarch64/neoverse_v3.S b/lib/cpus/aarch64/neoverse_v3.S
index 1f3db2b..69b6627 100644
--- a/lib/cpus/aarch64/neoverse_v3.S
+++ b/lib/cpus/aarch64/neoverse_v3.S
@@ -101,6 +101,10 @@
neoverse_v3_reset_func, \
neoverse_v3_core_pwr_dwn
-declare_cpu_ops neoverse_v3, NEOVERSE_V3_MIDR, \
+declare_cpu_ops_wa_4 neoverse_v3, NEOVERSE_V3_MIDR, \
neoverse_v3_reset_func, \
+ CPU_NO_EXTRA1_FUNC, \
+ CPU_NO_EXTRA2_FUNC, \
+ CPU_NO_EXTRA3_FUNC, \
+ check_erratum_neoverse_v3_7881, \
neoverse_v3_core_pwr_dwn