diff options
| -rw-r--r-- | arch/x86/mm/pageattr.c | 39 |
1 files changed, 39 insertions, 0 deletions
diff --git a/arch/x86/mm/pageattr.c b/arch/x86/mm/pageattr.c index c53de62..4b47ae0 100644 --- a/arch/x86/mm/pageattr.c +++ b/arch/x86/mm/pageattr.c @@ -666,6 +666,45 @@ static int split_large_page(pte_t *kpte, unsigned long address) return 0; } +#define populate_pud(cpa, addr, pgd, pgprot) (-1) + +/* + * Restrictions for kernel page table do not necessarily apply when mapping in + * an alternate PGD. + */ +static int populate_pgd(struct cpa_data *cpa, unsigned long addr) +{ + pgprot_t pgprot = __pgprot(_KERNPG_TABLE); + bool allocd_pgd = false; + pgd_t *pgd_entry; + pud_t *pud = NULL; /* shut up gcc */ + int ret; + + pgd_entry = cpa->pgd + pgd_index(addr); + + /* + * Allocate a PUD page and hand it down for mapping. + */ + if (pgd_none(*pgd_entry)) { + pud = (pud_t *)get_zeroed_page(GFP_KERNEL | __GFP_NOTRACK); + if (!pud) + return -1; + + set_pgd(pgd_entry, __pgd(__pa(pud) | _KERNPG_TABLE)); + allocd_pgd = true; + } + + pgprot_val(pgprot) &= ~pgprot_val(cpa->mask_clr); + pgprot_val(pgprot) |= pgprot_val(cpa->mask_set); + + ret = populate_pud(cpa, addr, pgd_entry, pgprot); + if (ret < 0) + return ret; + + cpa->numpages = ret; + return 0; +} + static int __cpa_process_fault(struct cpa_data *cpa, unsigned long vaddr, int primary) { |
