[S390] Use do_exception() in pagetable walk usercopy functions.
The pagetable walk usercopy functions have used a modified copy of the do_exception() function for fault handling. This lead to inconsistencies with recent changes to do_exception(), e.g. performance counters. This patch changes the pagetable walk usercopy code to call do_exception() directly, eliminating the redundancy. A new parameter is added to do_exception() to specify the fault address. Signed-off-by: Gerald Schaefer <gerald.schaefer@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
This commit is contained in:
parent
1ab947de29
commit
6c1e3e7943
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@ -93,6 +93,8 @@ extern struct uaccess_ops uaccess_mvcos;
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extern struct uaccess_ops uaccess_mvcos_switch;
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extern struct uaccess_ops uaccess_mvcos_switch;
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extern struct uaccess_ops uaccess_pt;
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extern struct uaccess_ops uaccess_pt;
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extern int __handle_fault(unsigned long, unsigned long, int);
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static inline int __put_user_fn(size_t size, void __user *ptr, void *x)
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static inline int __put_user_fn(size_t size, void __user *ptr, void *x)
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{
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{
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size = uaccess.copy_to_user_small(size, ptr, x);
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size = uaccess.copy_to_user_small(size, ptr, x);
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@ -23,85 +23,20 @@ static inline pte_t *follow_table(struct mm_struct *mm, unsigned long addr)
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pgd = pgd_offset(mm, addr);
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pgd = pgd_offset(mm, addr);
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if (pgd_none(*pgd) || unlikely(pgd_bad(*pgd)))
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if (pgd_none(*pgd) || unlikely(pgd_bad(*pgd)))
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return NULL;
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return (pte_t *) 0x3a;
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pud = pud_offset(pgd, addr);
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pud = pud_offset(pgd, addr);
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if (pud_none(*pud) || unlikely(pud_bad(*pud)))
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if (pud_none(*pud) || unlikely(pud_bad(*pud)))
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return NULL;
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return (pte_t *) 0x3b;
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pmd = pmd_offset(pud, addr);
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pmd = pmd_offset(pud, addr);
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if (pmd_none(*pmd) || unlikely(pmd_bad(*pmd)))
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if (pmd_none(*pmd) || unlikely(pmd_bad(*pmd)))
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return NULL;
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return (pte_t *) 0x10;
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return pte_offset_map(pmd, addr);
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return pte_offset_map(pmd, addr);
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}
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}
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static int __handle_fault(struct mm_struct *mm, unsigned long address,
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static __always_inline size_t __user_copy_pt(unsigned long uaddr, void *kptr,
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int write_access)
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{
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struct vm_area_struct *vma;
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int ret = -EFAULT;
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int fault;
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if (in_atomic())
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return ret;
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down_read(&mm->mmap_sem);
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vma = find_vma(mm, address);
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if (unlikely(!vma))
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goto out;
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if (unlikely(vma->vm_start > address)) {
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if (!(vma->vm_flags & VM_GROWSDOWN))
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goto out;
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if (expand_stack(vma, address))
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goto out;
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}
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if (!write_access) {
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/* page not present, check vm flags */
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if (!(vma->vm_flags & (VM_READ | VM_EXEC | VM_WRITE)))
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goto out;
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} else {
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if (!(vma->vm_flags & VM_WRITE))
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goto out;
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}
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survive:
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fault = handle_mm_fault(mm, vma, address, write_access ? FAULT_FLAG_WRITE : 0);
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if (unlikely(fault & VM_FAULT_ERROR)) {
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if (fault & VM_FAULT_OOM)
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goto out_of_memory;
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else if (fault & VM_FAULT_SIGBUS)
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goto out_sigbus;
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BUG();
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}
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if (fault & VM_FAULT_MAJOR)
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current->maj_flt++;
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else
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current->min_flt++;
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ret = 0;
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out:
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up_read(&mm->mmap_sem);
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return ret;
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out_of_memory:
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up_read(&mm->mmap_sem);
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if (is_global_init(current)) {
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yield();
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down_read(&mm->mmap_sem);
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goto survive;
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}
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printk("VM: killing process %s\n", current->comm);
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return ret;
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out_sigbus:
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up_read(&mm->mmap_sem);
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current->thread.prot_addr = address;
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current->thread.trap_no = 0x11;
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force_sig(SIGBUS, current);
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return ret;
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}
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static size_t __user_copy_pt(unsigned long uaddr, void *kptr,
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size_t n, int write_user)
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size_t n, int write_user)
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{
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{
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struct mm_struct *mm = current->mm;
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struct mm_struct *mm = current->mm;
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@ -114,12 +49,17 @@ retry:
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spin_lock(&mm->page_table_lock);
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spin_lock(&mm->page_table_lock);
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do {
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do {
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pte = follow_table(mm, uaddr);
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pte = follow_table(mm, uaddr);
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if (!pte || !pte_present(*pte) ||
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if ((unsigned long) pte < 0x1000)
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(write_user && !pte_write(*pte)))
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goto fault;
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goto fault;
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if (!pte_present(*pte)) {
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pte = (pte_t *) 0x11;
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goto fault;
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} else if (write_user && !pte_write(*pte)) {
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pte = (pte_t *) 0x04;
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goto fault;
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}
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pfn = pte_pfn(*pte);
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pfn = pte_pfn(*pte);
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offset = uaddr & (PAGE_SIZE - 1);
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offset = uaddr & (PAGE_SIZE - 1);
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size = min(n - done, PAGE_SIZE - offset);
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size = min(n - done, PAGE_SIZE - offset);
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if (write_user) {
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if (write_user) {
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@ -137,7 +77,7 @@ retry:
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return n - done;
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return n - done;
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fault:
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fault:
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spin_unlock(&mm->page_table_lock);
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spin_unlock(&mm->page_table_lock);
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if (__handle_fault(mm, uaddr, write_user))
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if (__handle_fault(uaddr, (unsigned long) pte, write_user))
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return n - done;
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return n - done;
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goto retry;
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goto retry;
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}
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}
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@ -146,30 +86,31 @@ fault:
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* Do DAT for user address by page table walk, return kernel address.
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* Do DAT for user address by page table walk, return kernel address.
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* This function needs to be called with current->mm->page_table_lock held.
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* This function needs to be called with current->mm->page_table_lock held.
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*/
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*/
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static unsigned long __dat_user_addr(unsigned long uaddr)
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static __always_inline unsigned long __dat_user_addr(unsigned long uaddr)
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{
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{
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struct mm_struct *mm = current->mm;
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struct mm_struct *mm = current->mm;
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unsigned long pfn, ret;
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unsigned long pfn;
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pte_t *pte;
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pte_t *pte;
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int rc;
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int rc;
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ret = 0;
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retry:
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retry:
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pte = follow_table(mm, uaddr);
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pte = follow_table(mm, uaddr);
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if (!pte || !pte_present(*pte))
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if ((unsigned long) pte < 0x1000)
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goto fault;
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goto fault;
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if (!pte_present(*pte)) {
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pte = (pte_t *) 0x11;
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goto fault;
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}
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pfn = pte_pfn(*pte);
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pfn = pte_pfn(*pte);
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ret = (pfn << PAGE_SHIFT) + (uaddr & (PAGE_SIZE - 1));
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return (pfn << PAGE_SHIFT) + (uaddr & (PAGE_SIZE - 1));
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out:
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return ret;
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fault:
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fault:
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spin_unlock(&mm->page_table_lock);
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spin_unlock(&mm->page_table_lock);
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rc = __handle_fault(mm, uaddr, 0);
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rc = __handle_fault(uaddr, (unsigned long) pte, 0);
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spin_lock(&mm->page_table_lock);
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spin_lock(&mm->page_table_lock);
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if (rc)
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if (!rc)
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goto out;
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goto retry;
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goto retry;
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return 0;
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}
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}
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size_t copy_from_user_pt(size_t n, const void __user *from, void *to)
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size_t copy_from_user_pt(size_t n, const void __user *from, void *to)
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@ -234,8 +175,12 @@ retry:
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spin_lock(&mm->page_table_lock);
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spin_lock(&mm->page_table_lock);
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do {
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do {
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pte = follow_table(mm, uaddr);
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pte = follow_table(mm, uaddr);
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if (!pte || !pte_present(*pte))
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if ((unsigned long) pte < 0x1000)
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goto fault;
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goto fault;
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if (!pte_present(*pte)) {
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pte = (pte_t *) 0x11;
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goto fault;
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}
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pfn = pte_pfn(*pte);
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pfn = pte_pfn(*pte);
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offset = uaddr & (PAGE_SIZE-1);
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offset = uaddr & (PAGE_SIZE-1);
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@ -249,9 +194,8 @@ retry:
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return done + 1;
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return done + 1;
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fault:
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fault:
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spin_unlock(&mm->page_table_lock);
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spin_unlock(&mm->page_table_lock);
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if (__handle_fault(mm, uaddr, 0)) {
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if (__handle_fault(uaddr, (unsigned long) pte, 0))
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return 0;
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return 0;
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}
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goto retry;
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goto retry;
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}
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}
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@ -284,7 +228,7 @@ static size_t copy_in_user_pt(size_t n, void __user *to,
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{
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{
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struct mm_struct *mm = current->mm;
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struct mm_struct *mm = current->mm;
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unsigned long offset_from, offset_to, offset_max, pfn_from, pfn_to,
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unsigned long offset_from, offset_to, offset_max, pfn_from, pfn_to,
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uaddr, done, size;
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uaddr, done, size, error_code;
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unsigned long uaddr_from = (unsigned long) from;
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unsigned long uaddr_from = (unsigned long) from;
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unsigned long uaddr_to = (unsigned long) to;
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unsigned long uaddr_to = (unsigned long) to;
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pte_t *pte_from, *pte_to;
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pte_t *pte_from, *pte_to;
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@ -298,17 +242,28 @@ static size_t copy_in_user_pt(size_t n, void __user *to,
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retry:
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retry:
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spin_lock(&mm->page_table_lock);
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spin_lock(&mm->page_table_lock);
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do {
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do {
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pte_from = follow_table(mm, uaddr_from);
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if (!pte_from || !pte_present(*pte_from)) {
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uaddr = uaddr_from;
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write_user = 0;
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write_user = 0;
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uaddr = uaddr_from;
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pte_from = follow_table(mm, uaddr_from);
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error_code = (unsigned long) pte_from;
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if (error_code < 0x1000)
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goto fault;
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if (!pte_present(*pte_from)) {
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error_code = 0x11;
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goto fault;
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goto fault;
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}
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}
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pte_to = follow_table(mm, uaddr_to);
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if (!pte_to || !pte_present(*pte_to) || !pte_write(*pte_to)) {
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uaddr = uaddr_to;
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write_user = 1;
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write_user = 1;
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uaddr = uaddr_to;
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pte_to = follow_table(mm, uaddr_to);
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error_code = (unsigned long) pte_to;
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if (error_code < 0x1000)
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goto fault;
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if (!pte_present(*pte_to)) {
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error_code = 0x11;
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goto fault;
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} else if (!pte_write(*pte_to)) {
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error_code = 0x04;
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goto fault;
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goto fault;
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}
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}
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@ -329,7 +284,7 @@ retry:
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return n - done;
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return n - done;
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fault:
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fault:
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spin_unlock(&mm->page_table_lock);
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spin_unlock(&mm->page_table_lock);
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if (__handle_fault(mm, uaddr, write_user))
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if (__handle_fault(uaddr, error_code, write_user))
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return n - done;
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return n - done;
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goto retry;
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goto retry;
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}
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}
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@ -442,6 +442,29 @@ no_context:
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}
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}
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#endif
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#endif
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int __handle_fault(unsigned long uaddr, unsigned long int_code, int write_user)
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{
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struct pt_regs regs;
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int access, fault;
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regs.psw.mask = psw_kernel_bits;
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if (!irqs_disabled())
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regs.psw.mask |= PSW_MASK_IO | PSW_MASK_EXT;
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regs.psw.addr = (unsigned long) __builtin_return_address(0);
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regs.psw.addr |= PSW_ADDR_AMODE;
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uaddr &= PAGE_MASK;
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access = write_user ? VM_WRITE : VM_READ;
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fault = do_exception(®s, access, uaddr | 2);
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if (unlikely(fault)) {
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if (fault & VM_FAULT_OOM) {
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pagefault_out_of_memory();
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fault = 0;
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} else if (fault & VM_FAULT_SIGBUS)
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do_sigbus(®s, int_code, uaddr);
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}
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return fault ? -EFAULT : 0;
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}
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#ifdef CONFIG_PFAULT
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#ifdef CONFIG_PFAULT
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/*
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/*
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* 'pfault' pseudo page faults routines.
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* 'pfault' pseudo page faults routines.
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