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[v3,3/3] arm64: errata: Add newer ARM cores to the spectre_bhb_loop_affected() lists

Message ID 20241219125317.v3.3.I4a9a527e03f663040721c5401c41de587d015c82@changeid
State New
Headers show
Series arm64: errata: Rework Spectre BHB mitigations to not assume "safe" | expand

Commit Message

Doug Anderson Dec. 19, 2024, 8:53 p.m. UTC
When comparing to the ARM list [1], it appears that several ARM cores
were missing from the lists in spectre_bhb_loop_affected(). Add them.

NOTE: for some of these cores it may not matter since other ways of
clearing the BHB may be used (like the CLRBHB instruction or ECBHB),
but it still seems good to have all the info from ARM's whitepaper
included.

[1] https://developer.arm.com/Arm%20Security%20Center/Spectre-BHB


Fixes: 558c303c9734 ("arm64: Mitigate spectre style branch history side channels")
Cc: stable@vger.kernel.org
Signed-off-by: Douglas Anderson <dianders@chromium.org>
---

Changes in v3:
- New

 arch/arm64/kernel/proton-pack.c | 15 ++++++++++++++-
 1 file changed, 14 insertions(+), 1 deletion(-)
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Patch

diff --git a/arch/arm64/kernel/proton-pack.c b/arch/arm64/kernel/proton-pack.c
index 06e04c9e6480..86d67f5a5a72 100644
--- a/arch/arm64/kernel/proton-pack.c
+++ b/arch/arm64/kernel/proton-pack.c
@@ -872,6 +872,14 @@  static u8 spectre_bhb_loop_affected(void)
 {
 	u8 k = 0;
 
+	static const struct midr_range spectre_bhb_k132_list[] = {
+		MIDR_ALL_VERSIONS(MIDR_CORTEX_X3),
+		MIDR_ALL_VERSIONS(MIDR_NEOVERSE_V2),
+	};
+	static const struct midr_range spectre_bhb_k38_list[] = {
+		MIDR_ALL_VERSIONS(MIDR_CORTEX_A715),
+		MIDR_ALL_VERSIONS(MIDR_CORTEX_A720),
+	};
 	static const struct midr_range spectre_bhb_k32_list[] = {
 		MIDR_ALL_VERSIONS(MIDR_CORTEX_A78),
 		MIDR_ALL_VERSIONS(MIDR_CORTEX_A78AE),
@@ -885,6 +893,7 @@  static u8 spectre_bhb_loop_affected(void)
 	};
 	static const struct midr_range spectre_bhb_k24_list[] = {
 		MIDR_ALL_VERSIONS(MIDR_CORTEX_A76),
+		MIDR_ALL_VERSIONS(MIDR_CORTEX_A76AE),
 		MIDR_ALL_VERSIONS(MIDR_CORTEX_A77),
 		MIDR_ALL_VERSIONS(MIDR_NEOVERSE_N1),
 		{},
@@ -899,7 +908,11 @@  static u8 spectre_bhb_loop_affected(void)
 		{},
 	};
 
-	if (is_midr_in_range_list(read_cpuid_id(), spectre_bhb_k32_list))
+	if (is_midr_in_range_list(read_cpuid_id(), spectre_bhb_k132_list))
+		k = 132;
+	else if (is_midr_in_range_list(read_cpuid_id(), spectre_bhb_k38_list))
+		k = 38;
+	else if (is_midr_in_range_list(read_cpuid_id(), spectre_bhb_k32_list))
 		k = 32;
 	else if (is_midr_in_range_list(read_cpuid_id(), spectre_bhb_k24_list))
 		k = 24;