[PATCH 2/3] arm64: Add missing ISB after invalidating TLB in __primary_switch

[Marc Zyngier]

Although there has been a bit of back and forth on the subject,
it appears that invalidating TLBs requires an ISB instruction
after the TLBI/DSB sequence, as documented in d0b7a302d58a
("Revert "arm64: Remove unnecessary ISBs from set_{pte,pmd,pud}"").

Add the missing ISB in __primary_switch, just in case.

Fixes: 3c5e9f238bc4 ("arm64: head.S: move KASLR processing out of __enable_mmu()")
Suggested-by: Will Deacon <will at kernel.org>
Signed-off-by: Marc Zyngier <maz at kernel.org>
---
 arch/arm64/kernel/head.S | 1 +
 1 file changed, 1 insertion(+)

diff --git a/arch/arm64/kernel/head.S b/arch/arm64/kernel/head.S
index 1e30b5550d2a..66b0e0b66e31 100644
--- a/arch/arm64/kernel/head.S
+++ b/arch/arm64/kernel/head.S
@@ -837,6 +837,7 @@ SYM_FUNC_START_LOCAL(__primary_switch)
 
 	tlbi	vmalle1				// Remove any stale TLB entries
 	dsb	nsh
+	isb
 
 	set_sctlr_el1	x19			// re-enable the MMU
 
-- 
2.29.2