diff options
Diffstat (limited to 'arch/um/kernel/skas/uaccess.c')
| -rw-r--r-- | arch/um/kernel/skas/uaccess.c | 34 |
1 files changed, 32 insertions, 2 deletions
diff --git a/arch/um/kernel/skas/uaccess.c b/arch/um/kernel/skas/uaccess.c index 1d8b119f2d0..302425b03d4 100644 --- a/arch/um/kernel/skas/uaccess.c +++ b/arch/um/kernel/skas/uaccess.c @@ -12,8 +12,38 @@ #include "kern_util.h" #include "os.h" -extern void *um_virt_to_phys(struct task_struct *task, unsigned long addr, - pte_t *pte_out); +static void *um_virt_to_phys(struct task_struct *task, unsigned long addr, + pte_t *pte_out) +{ + 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 (!pgd_present(*pgd)) + return ERR_PTR(-EINVAL); + + pud = pud_offset(pgd, addr); + if (!pud_present(*pud)) + return ERR_PTR(-EINVAL); + + 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); + + if (pte_out != NULL) + *pte_out = ptent; + return (void *) (pte_val(ptent) & PAGE_MASK) + (addr & ~PAGE_MASK); +} static unsigned long maybe_map(unsigned long virt, int is_write) { |