From 8e998fc24de47c55b47a887f6c95ab91acd4a720 Mon Sep 17 00:00:00 2001 From: Joerg Roedel Date: Fri, 19 Jul 2019 20:46:51 +0200 Subject: [PATCH] x86/mm: Sync also unmappings in vmalloc_sync_all() With huge-page ioremap areas the unmappings also need to be synced between all page-tables. Otherwise it can cause data corruption when a region is unmapped and later re-used. Make the vmalloc_sync_one() function ready to sync unmappings and make sure vmalloc_sync_all() iterates over all page-tables even when an unmapped PMD is found. Fixes: 5d72b4fba40ef ('x86, mm: support huge I/O mapping capability I/F') Signed-off-by: Joerg Roedel Signed-off-by: Thomas Gleixner Reviewed-by: Dave Hansen Link: https://lkml.kernel.org/r/20190719184652.11391-3-joro@8bytes.org --- arch/x86/mm/fault.c | 13 +++++-------- 1 file changed, 5 insertions(+), 8 deletions(-) diff --git a/arch/x86/mm/fault.c b/arch/x86/mm/fault.c index e64173db4970..9ceacd1156db 100644 --- a/arch/x86/mm/fault.c +++ b/arch/x86/mm/fault.c @@ -177,11 +177,12 @@ static inline pmd_t *vmalloc_sync_one(pgd_t *pgd, unsigned long address) pmd = pmd_offset(pud, address); pmd_k = pmd_offset(pud_k, address); + + if (pmd_present(*pmd) != pmd_present(*pmd_k)) + set_pmd(pmd, *pmd_k); + if (!pmd_present(*pmd_k)) return NULL; - - if (!pmd_present(*pmd)) - set_pmd(pmd, *pmd_k); else BUG_ON(pmd_pfn(*pmd) != pmd_pfn(*pmd_k)); @@ -203,17 +204,13 @@ void vmalloc_sync_all(void) spin_lock(&pgd_lock); list_for_each_entry(page, &pgd_list, lru) { spinlock_t *pgt_lock; - pmd_t *ret; /* the pgt_lock only for Xen */ pgt_lock = &pgd_page_get_mm(page)->page_table_lock; spin_lock(pgt_lock); - ret = vmalloc_sync_one(page_address(page), address); + vmalloc_sync_one(page_address(page), address); spin_unlock(pgt_lock); - - if (!ret) - break; } spin_unlock(&pgd_lock); }