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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: 5d72b4fba4 ('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
This commit is contained in:
Joerg Roedel 2019-07-19 20:46:51 +02:00 committed by Thomas Gleixner
parent 51b75b5b56
commit 8e998fc24d
1 changed files with 5 additions and 8 deletions
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13
arch/x86/mm/fault.c
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@ -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);
}