From: Joerg Roedel jroedel@suse.de
[ Upstream commit 8e998fc24de47c55b47a887f6c95ab91acd4a720 ]
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 jroedel@suse.de Signed-off-by: Thomas Gleixner tglx@linutronix.de Reviewed-by: Dave Hansen dave.hansen@linux.intel.com Link: https://lkml.kernel.org/r/20190719184652.11391-3-joro@8bytes.org Signed-off-by: Sasha Levin sashal@kernel.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 f3511f1a8f0ea..0e498683295b1 100644 --- a/arch/x86/mm/fault.c +++ b/arch/x86/mm/fault.c @@ -216,11 +216,12 @@ 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_k)) - return NULL;
- if (!pmd_present(*pmd)) + if (pmd_present(*pmd) != pmd_present(*pmd_k)) set_pmd(pmd, *pmd_k); + + if (!pmd_present(*pmd_k)) + return NULL; else BUG_ON(pmd_pfn(*pmd) != pmd_pfn(*pmd_k));
@@ -242,17 +243,13 @@ 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); }