From ca77b555c0aafa3070fbb67592abaaa1b8d31913 Mon Sep 17 00:00:00 2001 From: Jeff Dike Date: Mon, 4 Feb 2008 22:30:55 -0800 Subject: [PATCH] uml: add virt_to_pte Turn um_virt_to_phys into virt_to_pte, cleaning up a horrid interface. It's also made non-static and declared in pgtable.h because it'll be needed when the stubs get a vma. Signed-off-by: Jeff Dike Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- arch/um/kernel/skas/uaccess.c | 56 ++++++++++++++--------------------- include/asm-um/pgtable.h | 3 ++ 2 files changed, 26 insertions(+), 33 deletions(-) diff --git a/arch/um/kernel/skas/uaccess.c b/arch/um/kernel/skas/uaccess.c index d145565b5f4b..05b41dbc1dd9 100644 --- a/arch/um/kernel/skas/uaccess.c +++ b/arch/um/kernel/skas/uaccess.c @@ -13,70 +13,60 @@ #include "kern_util.h" #include "os.h" -static void *um_virt_to_phys(struct task_struct *task, unsigned long addr, - pte_t *pte_out) +pte_t *virt_to_pte(struct mm_struct *mm, unsigned long addr) { pgd_t *pgd; pud_t *pud; pmd_t *pmd; - pte_t *pte; - pte_t ptent; - if (task->mm == NULL) - return ERR_PTR(-EINVAL); - pgd = pgd_offset(task->mm, addr); + if (mm == NULL) + return NULL; + + pgd = pgd_offset(mm, addr); if (!pgd_present(*pgd)) - return ERR_PTR(-EINVAL); + return NULL; pud = pud_offset(pgd, addr); if (!pud_present(*pud)) - return ERR_PTR(-EINVAL); + return NULL; pmd = pmd_offset(pud, addr); if (!pmd_present(*pmd)) - return ERR_PTR(-EINVAL); - - pte = pte_offset_kernel(pmd, addr); - ptent = *pte; - if (!pte_present(ptent)) - return ERR_PTR(-EINVAL); + return NULL; - if (pte_out != NULL) - *pte_out = ptent; - return (void *) (pte_val(ptent) & PAGE_MASK) + (addr & ~PAGE_MASK); + return pte_offset_kernel(pmd, addr); } -static unsigned long maybe_map(unsigned long virt, int is_write) +static pte_t *maybe_map(unsigned long virt, int is_write) { - pte_t pte; - int err; + pte_t *pte = virt_to_pte(current->mm, virt); + int err, dummy_code; - void *phys = um_virt_to_phys(current, virt, &pte); - int dummy_code; - - if (IS_ERR(phys) || (is_write && !pte_write(pte))) { + if ((pte == NULL) || !pte_present(*pte) || + (is_write && !pte_write(*pte))) { err = handle_page_fault(virt, 0, is_write, 1, &dummy_code); if (err) - return -1UL; - phys = um_virt_to_phys(current, virt, NULL); + return NULL; + pte = virt_to_pte(current->mm, virt); } - if (IS_ERR(phys)) - phys = (void *) -1; + if (!pte_present(*pte)) + pte = NULL; - return (unsigned long) phys; + return pte; } static int do_op_one_page(unsigned long addr, int len, int is_write, int (*op)(unsigned long addr, int len, void *arg), void *arg) { struct page *page; + pte_t *pte; int n; - addr = maybe_map(addr, is_write); - if (addr == -1UL) + pte = maybe_map(addr, is_write); + if (pte == NULL) return -1; - page = phys_to_page(addr); + page = pte_page(*pte); addr = (unsigned long) kmap_atomic(page, KM_UML_USERCOPY) + (addr & ~PAGE_MASK); diff --git a/include/asm-um/pgtable.h b/include/asm-um/pgtable.h index 62ab94a4f1b6..fb477774a2e9 100644 --- a/include/asm-um/pgtable.h +++ b/include/asm-um/pgtable.h @@ -323,6 +323,9 @@ static inline pte_t pte_modify(pte_t pte, pgprot_t newprot) #define pte_unmap(pte) do { } while (0) #define pte_unmap_nested(pte) do { } while (0) +struct mm_struct; +extern pte_t *virt_to_pte(struct mm_struct *mm, unsigned long addr); + #define update_mmu_cache(vma,address,pte) do ; while (0) /* Encode and de-code a swap entry */ -- 2.30.2