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authorMark Rutland <mark.rutland@arm.com>2015-03-13 16:14:36 +0000
committerWill Deacon <will.deacon@arm.com>2015-03-17 16:58:55 +0000
commit424a383824faecce246691694fd5546859dac511 (patch)
tree024fbd4ac78cc51bee0e73b972452f0a407ab61f
parent137650aad96c9594683445e41afa8ac5a2097520 (diff)
downloadlinux-424a383824faecce246691694fd5546859dac511.tar.gz
arm64: fix hyp mode mismatch detection
Commit 828e9834e9a5b7e6 ("arm64: head: create a new function for setting the boot_cpu_mode flag") added BOOT_CPU_MODE_EL1, a nonzero value replacing uses of zero. However it failed to update __boot_cpu_mode appropriately. A CPU booted at EL2 writes BOOT_CPU_MODE_EL2 to __boot_cpu_mode[0], and a CPU booted at EL1 writes BOOT_CPU_MODE_EL1 to __boot_cpu_mode[1]. Later is_hyp_mode_mismatched() determines there to be a mismatch if __boot_cpu_mode[0] != __boot_cpu_mode[1]. If all CPUs are booted at EL1, __boot_cpu_mode[0] will be set to BOOT_CPU_MODE_EL1, but __boot_cpu_mode[1] will retain its initial value of zero, and is_hyp_mode_mismatched will erroneously determine that the boot modes are mismatched. This hasn't been a problem so far, but later patches which will make use of is_hyp_mode_mismatched() expect it to work correctly. This patch initialises __boot_cpu_mode[1] to BOOT_CPU_MODE_EL1, fixing the erroneous mismatch detection when all CPUs are booted at EL1. Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Marc Zyngier <marc.zyngier@arm.com> Tested-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Reviewed-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
-rw-r--r--arch/arm64/kernel/head.S2
1 files changed, 1 insertions, 1 deletions
diff --git a/arch/arm64/kernel/head.S b/arch/arm64/kernel/head.S
index 07f930540f4a..d17649d39392 100644
--- a/arch/arm64/kernel/head.S
+++ b/arch/arm64/kernel/head.S
@@ -588,7 +588,7 @@ ENDPROC(set_cpu_boot_mode_flag)
.align L1_CACHE_SHIFT
ENTRY(__boot_cpu_mode)
.long BOOT_CPU_MODE_EL2
- .long 0
+ .long BOOT_CPU_MODE_EL1
.popsection
#ifdef CONFIG_SMP