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author | Kristina Martsenko <kristina.martsenko@arm.com> | 2020-03-13 14:34:54 +0530 |
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committer | Catalin Marinas <catalin.marinas@arm.com> | 2020-03-18 09:50:19 +0000 |
commit | deeaac5175a577cbbe1a2319903781d0a7ef7720 (patch) | |
tree | 7957e4493891614ba52dc0cdab0b6976206f7aef /arch/arm64/include/asm/cpufeature.h | |
parent | 8c176e1625a66d35362d4eac7ceab55c1229b481 (diff) | |
download | linux-deeaac5175a577cbbe1a2319903781d0a7ef7720.tar.gz linux-deeaac5175a577cbbe1a2319903781d0a7ef7720.tar.bz2 linux-deeaac5175a577cbbe1a2319903781d0a7ef7720.zip |
arm64: cpufeature: handle conflicts based on capability
Each system capability can be of either boot, local, or system scope,
depending on when the state of the capability is finalized. When we
detect a conflict on a late CPU, we either offline the CPU or panic the
system. We currently always panic if the conflict is caused by a boot
scope capability, and offline the CPU if the conflict is caused by a
local or system scope capability.
We're going to want to add a new capability (for pointer authentication)
which needs to be boot scope but doesn't need to panic the system when a
conflict is detected. So add a new flag to specify whether the
capability requires the system to panic or not. Current boot scope
capabilities are updated to set the flag, so there should be no
functional change as a result of this patch.
Signed-off-by: Amit Daniel Kachhap <amit.kachhap@arm.com>
Signed-off-by: Kristina Martsenko <kristina.martsenko@arm.com>
Reviewed-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Diffstat (limited to 'arch/arm64/include/asm/cpufeature.h')
-rw-r--r-- | arch/arm64/include/asm/cpufeature.h | 12 |
1 files changed, 10 insertions, 2 deletions
diff --git a/arch/arm64/include/asm/cpufeature.h b/arch/arm64/include/asm/cpufeature.h index cea3c1cdf252..46388e65bbcd 100644 --- a/arch/arm64/include/asm/cpufeature.h +++ b/arch/arm64/include/asm/cpufeature.h @@ -208,6 +208,10 @@ extern struct arm64_ftr_reg arm64_ftr_reg_ctrel0; * In some non-typical cases either both (a) and (b), or neither, * should be permitted. This can be described by including neither * or both flags in the capability's type field. + * + * In case of a conflict, the CPU is prevented from booting. If the + * ARM64_CPUCAP_PANIC_ON_CONFLICT flag is specified for the capability, + * then a kernel panic is triggered. */ @@ -240,6 +244,8 @@ extern struct arm64_ftr_reg arm64_ftr_reg_ctrel0; #define ARM64_CPUCAP_PERMITTED_FOR_LATE_CPU ((u16)BIT(4)) /* Is it safe for a late CPU to miss this capability when system has it */ #define ARM64_CPUCAP_OPTIONAL_FOR_LATE_CPU ((u16)BIT(5)) +/* Panic when a conflict is detected */ +#define ARM64_CPUCAP_PANIC_ON_CONFLICT ((u16)BIT(6)) /* * CPU errata workarounds that need to be enabled at boot time if one or @@ -279,9 +285,11 @@ extern struct arm64_ftr_reg arm64_ftr_reg_ctrel0; /* * CPU feature used early in the boot based on the boot CPU. All secondary - * CPUs must match the state of the capability as detected by the boot CPU. + * CPUs must match the state of the capability as detected by the boot CPU. In + * case of a conflict, a kernel panic is triggered. */ -#define ARM64_CPUCAP_STRICT_BOOT_CPU_FEATURE ARM64_CPUCAP_SCOPE_BOOT_CPU +#define ARM64_CPUCAP_STRICT_BOOT_CPU_FEATURE \ + (ARM64_CPUCAP_SCOPE_BOOT_CPU | ARM64_CPUCAP_PANIC_ON_CONFLICT) struct arm64_cpu_capabilities { const char *desc; |