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arm64: errata: Add newer ARM cores to the spectre_bhb_loop_affected()…
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commit a595138 upstream.

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: 558c303 ("arm64: Mitigate spectre style branch history side channels")
Cc: stable@vger.kernel.org
Signed-off-by: Douglas Anderson <dianders@chromium.org>
Reviewed-by: James Morse <james.morse@arm.com>
Link: https://lore.kernel.org/r/20250107120555.v4.5.I4a9a527e03f663040721c5401c41de587d015c82@changeid
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Douglas Anderson authored and Greg Kroah-Hartman committed Apr 25, 2025
1 parent d784cb1 commit 4117975
Showing 1 changed file with 14 additions and 1 deletion.
15 changes: 14 additions & 1 deletion arch/arm64/kernel/proton-pack.c
Original file line number Diff line number Diff line change
Expand Up @@ -876,6 +876,14 @@ 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),
Expand All @@ -889,6 +897,7 @@ 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),
MIDR_ALL_VERSIONS(MIDR_QCOM_KRYO_4XX_GOLD),
Expand All @@ -904,7 +913,11 @@ 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;
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