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| author | Mark Rutland | 2015-03-13 17:14:36 +0100 |
|---|---|---|
| committer | Will Deacon | 2015-03-17 17:58:55 +0100 |
| commit | 424a383824faecce246691694fd5546859dac511 (patch) | |
| tree | 024fbd4ac78cc51bee0e73b972452f0a407ab61f /arch/arm64/kernel/head.S | |
| parent | arm64: apply alternatives for !SMP kernels (diff) | |
| download | kernel-qcow2-linux-424a383824faecce246691694fd5546859dac511.tar.gz kernel-qcow2-linux-424a383824faecce246691694fd5546859dac511.tar.xz kernel-qcow2-linux-424a383824faecce246691694fd5546859dac511.zip | |
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>
Diffstat (limited to 'arch/arm64/kernel/head.S')
| -rw-r--r-- | arch/arm64/kernel/head.S | 2 |
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 |