diff options
Diffstat (limited to 'arch/x86/mm/pageattr.c')
| -rw-r--r-- | arch/x86/mm/pageattr.c | 97 |
1 files changed, 72 insertions, 25 deletions
diff --git a/arch/x86/mm/pageattr.c b/arch/x86/mm/pageattr.c index a1b1c88f9caf..091934e1d0d9 100644 --- a/arch/x86/mm/pageattr.c +++ b/arch/x86/mm/pageattr.c @@ -473,6 +473,19 @@ try_preserve_large_page(pte_t *kpte, unsigned long address, pgprot_val(req_prot) |= pgprot_val(cpa->mask_set); /* + * Set the PSE and GLOBAL flags only if the PRESENT flag is + * set otherwise pmd_present/pmd_huge will return true even on + * a non present pmd. The canon_pgprot will clear _PAGE_GLOBAL + * for the ancient hardware that doesn't support it. + */ + if (pgprot_val(new_prot) & _PAGE_PRESENT) + pgprot_val(new_prot) |= _PAGE_PSE | _PAGE_GLOBAL; + else + pgprot_val(new_prot) &= ~(_PAGE_PSE | _PAGE_GLOBAL); + + new_prot = canon_pgprot(new_prot); + + /* * old_pte points to the large page base address. So we need * to add the offset of the virtual address: */ @@ -517,7 +530,7 @@ try_preserve_large_page(pte_t *kpte, unsigned long address, * The address is aligned and the number of pages * covers the full page. */ - new_pte = pfn_pte(pte_pfn(old_pte), canon_pgprot(new_prot)); + new_pte = pfn_pte(pte_pfn(old_pte), new_prot); __set_pmd_pte(kpte, address, new_pte); cpa->flags |= CPA_FLUSHTLB; do_split = 0; @@ -529,21 +542,13 @@ out_unlock: return do_split; } -static int split_large_page(pte_t *kpte, unsigned long address) +int __split_large_page(pte_t *kpte, unsigned long address, pte_t *pbase) { unsigned long pfn, pfninc = 1; unsigned int i, level; - pte_t *pbase, *tmp; + pte_t *tmp; pgprot_t ref_prot; - struct page *base; - - if (!debug_pagealloc) - spin_unlock(&cpa_lock); - base = alloc_pages(GFP_KERNEL | __GFP_NOTRACK, 0); - if (!debug_pagealloc) - spin_lock(&cpa_lock); - if (!base) - return -ENOMEM; + struct page *base = virt_to_page(pbase); spin_lock(&pgd_lock); /* @@ -551,10 +556,11 @@ static int split_large_page(pte_t *kpte, unsigned long address) * up for us already: */ tmp = lookup_address(address, &level); - if (tmp != kpte) - goto out_unlock; + if (tmp != kpte) { + spin_unlock(&pgd_lock); + return 1; + } - pbase = (pte_t *)page_address(base); paravirt_alloc_pte(&init_mm, page_to_pfn(base)); ref_prot = pte_pgprot(pte_clrhuge(*kpte)); /* @@ -568,16 +574,35 @@ static int split_large_page(pte_t *kpte, unsigned long address) #ifdef CONFIG_X86_64 if (level == PG_LEVEL_1G) { pfninc = PMD_PAGE_SIZE >> PAGE_SHIFT; - pgprot_val(ref_prot) |= _PAGE_PSE; + /* + * Set the PSE flags only if the PRESENT flag is set + * otherwise pmd_present/pmd_huge will return true + * even on a non present pmd. + */ + if (pgprot_val(ref_prot) & _PAGE_PRESENT) + pgprot_val(ref_prot) |= _PAGE_PSE; + else + pgprot_val(ref_prot) &= ~_PAGE_PSE; } #endif /* + * Set the GLOBAL flags only if the PRESENT flag is set + * otherwise pmd/pte_present will return true even on a non + * present pmd/pte. The canon_pgprot will clear _PAGE_GLOBAL + * for the ancient hardware that doesn't support it. + */ + if (pgprot_val(ref_prot) & _PAGE_PRESENT) + pgprot_val(ref_prot) |= _PAGE_GLOBAL; + else + pgprot_val(ref_prot) &= ~_PAGE_GLOBAL; + + /* * Get the target pfn from the original entry: */ pfn = pte_pfn(*kpte); for (i = 0; i < PTRS_PER_PTE; i++, pfn += pfninc) - set_pte(&pbase[i], pfn_pte(pfn, ref_prot)); + set_pte(&pbase[i], pfn_pte(pfn, canon_pgprot(ref_prot))); if (pfn_range_is_mapped(PFN_DOWN(__pa(address)), PFN_DOWN(__pa(address)) + 1)) @@ -601,17 +626,27 @@ static int split_large_page(pte_t *kpte, unsigned long address) * going on. */ __flush_tlb_all(); + spin_unlock(&pgd_lock); - base = NULL; + return 0; +} -out_unlock: - /* - * If we dropped out via the lookup_address check under - * pgd_lock then stick the page back into the pool: - */ - if (base) +static int split_large_page(pte_t *kpte, unsigned long address) +{ + pte_t *pbase; + struct page *base; + + if (!debug_pagealloc) + spin_unlock(&cpa_lock); + base = alloc_pages(GFP_KERNEL | __GFP_NOTRACK, 0); + if (!debug_pagealloc) + spin_lock(&cpa_lock); + if (!base) + return -ENOMEM; + + pbase = (pte_t *)page_address(base); + if (__split_large_page(kpte, address, pbase)) __free_page(base); - spin_unlock(&pgd_lock); return 0; } @@ -682,6 +717,18 @@ repeat: new_prot = static_protections(new_prot, address, pfn); /* + * Set the GLOBAL flags only if the PRESENT flag is + * set otherwise pte_present will return true even on + * a non present pte. The canon_pgprot will clear + * _PAGE_GLOBAL for the ancient hardware that doesn't + * support it. + */ + if (pgprot_val(new_prot) & _PAGE_PRESENT) + pgprot_val(new_prot) |= _PAGE_GLOBAL; + else + pgprot_val(new_prot) &= ~_PAGE_GLOBAL; + + /* * We need to keep the pfn from the existing PTE, * after all we're only going to change it's attributes * not the memory it points to |