From: Sebastian Andrzej Siewior Date: Mon, 11 Mar 2013 21:37:27 +0100 Subject: arm/highmem: Flush tlb on unmap Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/4.18/older/patches-4.18.5-rt3.tar.xz The tlb should be flushed on unmap and thus make the mapping entry invalid. This is only done in the non-debug case which does not look right. Signed-off-by: Sebastian Andrzej Siewior --- arch/arm/mm/highmem.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/arch/arm/mm/highmem.c +++ b/arch/arm/mm/highmem.c @@ -112,10 +112,10 @@ void __kunmap_atomic(void *kvaddr) __cpuc_flush_dcache_area((void *)vaddr, PAGE_SIZE); #ifdef CONFIG_DEBUG_HIGHMEM BUG_ON(vaddr != __fix_to_virt(idx)); - set_fixmap_pte(idx, __pte(0)); #else (void) idx; /* to kill a warning */ #endif + set_fixmap_pte(idx, __pte(0)); kmap_atomic_idx_pop(); } else if (vaddr >= PKMAP_ADDR(0) && vaddr < PKMAP_ADDR(LAST_PKMAP)) { /* this address was obtained through kmap_high_get() */