From: Will Deacon <will@kernel.org>
Date: Sat, 7 Jun 2025 15:25:16 +0000 (+0000)
Subject: arm64: errata: Add missing sentinels to Spectre-BHB MIDR arrays
X-Git-Tag: v5.10.239~24
X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=e68da90ac00d8b681561aeb8f5d6c47af3a04861;p=thirdparty%2Fkernel%2Fstable.git

arm64: errata: Add missing sentinels to Spectre-BHB MIDR arrays

[ Upstream commit fee4d171451c1ad9e8aaf65fc0ab7d143a33bd72 ]

Commit a5951389e58d ("arm64: errata: Add newer ARM cores to the
spectre_bhb_loop_affected() lists") added some additional CPUs to the
Spectre-BHB workaround, including some new arrays for designs that
require new 'k' values for the workaround to be effective.

Unfortunately, the new arrays omitted the sentinel entry and so
is_midr_in_range_list() will walk off the end when it doesn't find a
match. With UBSAN enabled, this leads to a crash during boot when
is_midr_in_range_list() is inlined (which was more common prior to
c8c2647e69be ("arm64: Make  _midr_in_range_list() an exported
function")):

 |  Internal error: aarch64 BRK: 00000000f2000001 [#1] PREEMPT SMP
 |  pstate: 804000c5 (Nzcv daIF +PAN -UAO -TCO -DIT -SSBS BTYPE=--)
 |  pc : spectre_bhb_loop_affected+0x28/0x30
 |  lr : is_spectre_bhb_affected+0x170/0x190
 | [...]
 |  Call trace:
 |   spectre_bhb_loop_affected+0x28/0x30
 |   update_cpu_capabilities+0xc0/0x184
 |   init_cpu_features+0x188/0x1a4
 |   cpuinfo_store_boot_cpu+0x4c/0x60
 |   smp_prepare_boot_cpu+0x38/0x54
 |   start_kernel+0x8c/0x478
 |   __primary_switched+0xc8/0xd4
 |  Code: 6b09011f 54000061 52801080 d65f03c0 (d4200020)
 |  ---[ end trace 0000000000000000 ]---
 |  Kernel panic - not syncing: aarch64 BRK: Fatal exception

Add the missing sentinel entries.

Cc: Lee Jones <lee@kernel.org>
Cc: James Morse <james.morse@arm.com>
Cc: Doug Anderson <dianders@chromium.org>
Cc: Shameer Kolothum <shameerali.kolothum.thodi@huawei.com>
Cc: <stable@vger.kernel.org>
Reported-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Fixes: a5951389e58d ("arm64: errata: Add newer ARM cores to the spectre_bhb_loop_affected() lists")
Signed-off-by: Will Deacon <will@kernel.org>
Reviewed-by: Lee Jones <lee@kernel.org>
Reviewed-by: Douglas Anderson <dianders@chromium.org>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Link: https://lore.kernel.org/r/20250501104747.28431-1-will@kernel.org
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Pu Lehui <pulehui@huawei.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---

diff --git a/arch/arm64/kernel/proton-pack.c b/arch/arm64/kernel/proton-pack.c
index 68a75afba0c42..1e1615442bb27 100644
--- a/arch/arm64/kernel/proton-pack.c
+++ b/arch/arm64/kernel/proton-pack.c
@@ -887,10 +887,12 @@ static u8 spectre_bhb_loop_affected(void)
 	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),