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

JIRA: https://issues.redhat.com/browse/RHEL-119901

commit fee4d17
Author: Will Deacon <[email protected]>
Date:   Thu, 1 May 2025 11:47:47 +0100

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

    Commit a595138 ("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
    c8c2647 ("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 <[email protected]>
    Cc: James Morse <[email protected]>
    Cc: Doug Anderson <[email protected]>
    Cc: Shameer Kolothum <[email protected]>
    Cc: <[email protected]>
    Reported-by: Greg Kroah-Hartman <[email protected]>
    Fixes: a595138 ("arm64: errata: Add newer ARM cores to the spectre_bhb_loop_affected() lists")
    Signed-off-by: Will Deacon <[email protected]>
    Reviewed-by: Lee Jones <[email protected]>
    Reviewed-by: Douglas Anderson <[email protected]>
    Reviewed-by: Greg Kroah-Hartman <[email protected]>
    Link: https://lore.kernel.org/r/[email protected]
    Signed-off-by: Catalin Marinas <[email protected]>

Signed-off-by: Waiman Long <[email protected]>

Author: Waiman-Long

arch/arm64/kernel/proton-pack.c

@@ -879,10 +879,12 @@ 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),