From 424a383824faecce246691694fd5546859dac511 Mon Sep 17 00:00:00 2001 From: Mark Rutland Date: Fri, 13 Mar 2015 16:14:36 +0000 Subject: [PATCH] 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 Cc: Marc Zyngier Tested-by: Ard Biesheuvel Reviewed-by: Ard Biesheuvel Signed-off-by: Mark Rutland Signed-off-by: Will Deacon --- arch/arm64/kernel/head.S | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) 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 -- 2.20.1