From 58a18fe95e83b8396605154db04d73b08063f31b Mon Sep 17 00:00:00 2001 From: Joerg Roedel Date: Fri, 14 Aug 2020 17:19:46 +0200 Subject: x86/mm/64: Do not sync vmalloc/ioremap mappings Remove the code to sync the vmalloc and ioremap ranges for x86-64. The page-table pages are all pre-allocated so that synchronization is no longer necessary. This is a patch that already went into the kernel as: commit 8bb9bf242d1f ("x86/mm/64: Do not sync vmalloc/ioremap mappings") But it had to be reverted later because it unveiled a bug from: commit 6eb82f994026 ("x86/mm: Pre-allocate P4D/PUD pages for vmalloc area") The bug in that commit causes the P4D/PUD pages not to be correctly allocated, making the synchronization still necessary. That issue got fixed meanwhile upstream: commit 995909a4e22b ("x86/mm/64: Do not dereference non-present PGD entries") With that fix it is safe again to remove the page-table synchronization for vmalloc/ioremap ranges on x86-64. Signed-off-by: Joerg Roedel Signed-off-by: Ingo Molnar Link: https://lore.kernel.org/r/20200814151947.26229-2-joro@8bytes.org --- arch/x86/mm/init_64.c | 5 ----- 1 file changed, 5 deletions(-) (limited to 'arch/x86/mm') diff --git a/arch/x86/mm/init_64.c b/arch/x86/mm/init_64.c index a4ac13cc3fdc..777d83546764 100644 --- a/arch/x86/mm/init_64.c +++ b/arch/x86/mm/init_64.c @@ -217,11 +217,6 @@ static void sync_global_pgds(unsigned long start, unsigned long end) sync_global_pgds_l4(start, end); } -void arch_sync_kernel_mappings(unsigned long start, unsigned long end) -{ - sync_global_pgds(start, end); -} - /* * NOTE: This function is marked __ref because it calls __init function * (alloc_bootmem_pages). It's safe to do it ONLY when after_bootmem == 0. -- cgit v1.2.3