x86/mm: Sync also unmappings in vmalloc_sync_all() (8e998fc2) · Commits · 戴 / test

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: ('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

arch/x86/mm/fault.c

+5 −8

Original line number	Diff line number	Diff line
		@@ -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_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));

		@@ -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);
		}

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