diff options
Diffstat (limited to 'arch/s390/lib/uaccess_pt.c')
| -rw-r--r-- | arch/s390/lib/uaccess_pt.c | 471 |
1 files changed, 0 insertions, 471 deletions
diff --git a/arch/s390/lib/uaccess_pt.c b/arch/s390/lib/uaccess_pt.c deleted file mode 100644 index 8d39760bae68..000000000000 --- a/arch/s390/lib/uaccess_pt.c +++ /dev/null @@ -1,471 +0,0 @@ -/* - * User access functions based on page table walks for enhanced - * system layout without hardware support. - * - * Copyright IBM Corp. 2006, 2012 - * Author(s): Gerald Schaefer (gerald.schaefer@de.ibm.com) - */ - -#include <linux/errno.h> -#include <linux/hardirq.h> -#include <linux/mm.h> -#include <linux/hugetlb.h> -#include <asm/uaccess.h> -#include <asm/futex.h> -#include "uaccess.h" - -#ifndef CONFIG_64BIT -#define AHI "ahi" -#define SLR "slr" -#else -#define AHI "aghi" -#define SLR "slgr" -#endif - -static unsigned long strnlen_kernel(const char __user *src, unsigned long count) -{ - register unsigned long reg0 asm("0") = 0UL; - unsigned long tmp1, tmp2; - - asm volatile( - " la %2,0(%1)\n" - " la %3,0(%0,%1)\n" - " "SLR" %0,%0\n" - "0: srst %3,%2\n" - " jo 0b\n" - " la %0,1(%3)\n" /* strnlen_kernel results includes \0 */ - " "SLR" %0,%1\n" - "1:\n" - EX_TABLE(0b,1b) - : "+a" (count), "+a" (src), "=a" (tmp1), "=a" (tmp2) - : "d" (reg0) : "cc", "memory"); - return count; -} - -static unsigned long copy_in_kernel(void __user *to, const void __user *from, - unsigned long count) -{ - unsigned long tmp1; - - asm volatile( - " "AHI" %0,-1\n" - " jo 5f\n" - " bras %3,3f\n" - "0:"AHI" %0,257\n" - "1: mvc 0(1,%1),0(%2)\n" - " la %1,1(%1)\n" - " la %2,1(%2)\n" - " "AHI" %0,-1\n" - " jnz 1b\n" - " j 5f\n" - "2: mvc 0(256,%1),0(%2)\n" - " la %1,256(%1)\n" - " la %2,256(%2)\n" - "3:"AHI" %0,-256\n" - " jnm 2b\n" - "4: ex %0,1b-0b(%3)\n" - "5:"SLR" %0,%0\n" - "6:\n" - EX_TABLE(1b,6b) EX_TABLE(2b,0b) EX_TABLE(4b,0b) - : "+a" (count), "+a" (to), "+a" (from), "=a" (tmp1) - : : "cc", "memory"); - return count; -} - -/* - * Returns kernel address for user virtual address. If the returned address is - * >= -4095 (IS_ERR_VALUE(x) returns true), a fault has occurred and the - * address contains the (negative) exception code. - */ -#ifdef CONFIG_64BIT - -static unsigned long follow_table(struct mm_struct *mm, - unsigned long address, int write) -{ - unsigned long *table = (unsigned long *)__pa(mm->pgd); - - if (unlikely(address > mm->context.asce_limit - 1)) - return -0x38UL; - switch (mm->context.asce_bits & _ASCE_TYPE_MASK) { - case _ASCE_TYPE_REGION1: - table = table + ((address >> 53) & 0x7ff); - if (unlikely(*table & _REGION_ENTRY_INVALID)) - return -0x39UL; - table = (unsigned long *)(*table & _REGION_ENTRY_ORIGIN); - /* fallthrough */ - case _ASCE_TYPE_REGION2: - table = table + ((address >> 42) & 0x7ff); - if (unlikely(*table & _REGION_ENTRY_INVALID)) - return -0x3aUL; - table = (unsigned long *)(*table & _REGION_ENTRY_ORIGIN); - /* fallthrough */ - case _ASCE_TYPE_REGION3: - table = table + ((address >> 31) & 0x7ff); - if (unlikely(*table & _REGION_ENTRY_INVALID)) - return -0x3bUL; - table = (unsigned long *)(*table & _REGION_ENTRY_ORIGIN); - /* fallthrough */ - case _ASCE_TYPE_SEGMENT: - table = table + ((address >> 20) & 0x7ff); - if (unlikely(*table & _SEGMENT_ENTRY_INVALID)) - return -0x10UL; - if (unlikely(*table & _SEGMENT_ENTRY_LARGE)) { - if (write && (*table & _SEGMENT_ENTRY_PROTECT)) - return -0x04UL; - return (*table & _SEGMENT_ENTRY_ORIGIN_LARGE) + - (address & ~_SEGMENT_ENTRY_ORIGIN_LARGE); - } - table = (unsigned long *)(*table & _SEGMENT_ENTRY_ORIGIN); - } - table = table + ((address >> 12) & 0xff); - if (unlikely(*table & _PAGE_INVALID)) - return -0x11UL; - if (write && (*table & _PAGE_PROTECT)) - return -0x04UL; - return (*table & PAGE_MASK) + (address & ~PAGE_MASK); -} - -#else /* CONFIG_64BIT */ - -static unsigned long follow_table(struct mm_struct *mm, - unsigned long address, int write) -{ - unsigned long *table = (unsigned long *)__pa(mm->pgd); - - table = table + ((address >> 20) & 0x7ff); - if (unlikely(*table & _SEGMENT_ENTRY_INVALID)) - return -0x10UL; - table = (unsigned long *)(*table & _SEGMENT_ENTRY_ORIGIN); - table = table + ((address >> 12) & 0xff); - if (unlikely(*table & _PAGE_INVALID)) - return -0x11UL; - if (write && (*table & _PAGE_PROTECT)) - return -0x04UL; - return (*table & PAGE_MASK) + (address & ~PAGE_MASK); -} - -#endif /* CONFIG_64BIT */ - -static inline unsigned long __user_copy_pt(unsigned long uaddr, void *kptr, - unsigned long n, int write_user) -{ - struct mm_struct *mm = current->mm; - unsigned long offset, done, size, kaddr; - void *from, *to; - - if (!mm) - return n; - done = 0; -retry: - spin_lock(&mm->page_table_lock); - do { - kaddr = follow_table(mm, uaddr, write_user); - if (IS_ERR_VALUE(kaddr)) - goto fault; - - offset = uaddr & ~PAGE_MASK; - size = min(n - done, PAGE_SIZE - offset); - if (write_user) { - to = (void *) kaddr; - from = kptr + done; - } else { - from = (void *) kaddr; - to = kptr + done; - } - memcpy(to, from, size); - done += size; - uaddr += size; - } while (done < n); - spin_unlock(&mm->page_table_lock); - return n - done; -fault: - spin_unlock(&mm->page_table_lock); - if (__handle_fault(uaddr, -kaddr, write_user)) - return n - done; - goto retry; -} - -/* - * Do DAT for user address by page table walk, return kernel address. - * This function needs to be called with current->mm->page_table_lock held. - */ -static inline unsigned long __dat_user_addr(unsigned long uaddr, int write) -{ - struct mm_struct *mm = current->mm; - unsigned long kaddr; - int rc; - -retry: - kaddr = follow_table(mm, uaddr, write); - if (IS_ERR_VALUE(kaddr)) - goto fault; - - return kaddr; -fault: - spin_unlock(&mm->page_table_lock); - rc = __handle_fault(uaddr, -kaddr, write); - spin_lock(&mm->page_table_lock); - if (!rc) - goto retry; - return 0; -} - -unsigned long copy_from_user_pt(void *to, const void __user *from, unsigned long n) -{ - unsigned long rc; - - if (segment_eq(get_fs(), KERNEL_DS)) - return copy_in_kernel((void __user *) to, from, n); - rc = __user_copy_pt((unsigned long) from, to, n, 0); - if (unlikely(rc)) - memset(to + n - rc, 0, rc); - return rc; -} - -unsigned long copy_to_user_pt(void __user *to, const void *from, unsigned long n) -{ - if (segment_eq(get_fs(), KERNEL_DS)) - return copy_in_kernel(to, (void __user *) from, n); - return __user_copy_pt((unsigned long) to, (void *) from, n, 1); -} - -unsigned long clear_user_pt(void __user *to, unsigned long n) -{ - void *zpage = (void *) empty_zero_page; - unsigned long done, size, ret; - - done = 0; - do { - if (n - done > PAGE_SIZE) - size = PAGE_SIZE; - else - size = n - done; - if (segment_eq(get_fs(), KERNEL_DS)) - ret = copy_in_kernel(to, (void __user *) zpage, n); - else - ret = __user_copy_pt((unsigned long) to, zpage, size, 1); - done += size; - to += size; - if (ret) - return ret + n - done; - } while (done < n); - return 0; -} - -unsigned long strnlen_user_pt(const char __user *src, unsigned long count) -{ - unsigned long uaddr = (unsigned long) src; - struct mm_struct *mm = current->mm; - unsigned long offset, done, len, kaddr; - unsigned long len_str; - - if (unlikely(!count)) - return 0; - if (segment_eq(get_fs(), KERNEL_DS)) - return strnlen_kernel(src, count); - if (!mm) - return 0; - done = 0; -retry: - spin_lock(&mm->page_table_lock); - do { - kaddr = follow_table(mm, uaddr, 0); - if (IS_ERR_VALUE(kaddr)) - goto fault; - - offset = uaddr & ~PAGE_MASK; - len = min(count - done, PAGE_SIZE - offset); - len_str = strnlen((char *) kaddr, len); - done += len_str; - uaddr += len_str; - } while ((len_str == len) && (done < count)); - spin_unlock(&mm->page_table_lock); - return done + 1; -fault: - spin_unlock(&mm->page_table_lock); - if (__handle_fault(uaddr, -kaddr, 0)) - return 0; - goto retry; -} - -long strncpy_from_user_pt(char *dst, const char __user *src, long count) -{ - unsigned long done, len, offset, len_str; - - if (unlikely(count <= 0)) - return 0; - done = 0; - do { - offset = (unsigned long)src & ~PAGE_MASK; - len = min(count - done, PAGE_SIZE - offset); - if (segment_eq(get_fs(), KERNEL_DS)) { - if (copy_in_kernel((void __user *) dst, src, len)) - return -EFAULT; - } else { - if (__user_copy_pt((unsigned long) src, dst, len, 0)) - return -EFAULT; - } - len_str = strnlen(dst, len); - done += len_str; - src += len_str; - dst += len_str; - } while ((len_str == len) && (done < count)); - return done; -} - -unsigned long copy_in_user_pt(void __user *to, const void __user *from, - unsigned long n) -{ - struct mm_struct *mm = current->mm; - unsigned long offset_max, uaddr, done, size, error_code; - unsigned long uaddr_from = (unsigned long) from; - unsigned long uaddr_to = (unsigned long) to; - unsigned long kaddr_to, kaddr_from; - int write_user; - - if (segment_eq(get_fs(), KERNEL_DS)) - return copy_in_kernel(to, from, n); - if (!mm) - return n; - done = 0; -retry: - spin_lock(&mm->page_table_lock); - do { - write_user = 0; - uaddr = uaddr_from; - kaddr_from = follow_table(mm, uaddr_from, 0); - error_code = kaddr_from; - if (IS_ERR_VALUE(error_code)) - goto fault; - - write_user = 1; - uaddr = uaddr_to; - kaddr_to = follow_table(mm, uaddr_to, 1); - error_code = (unsigned long) kaddr_to; - if (IS_ERR_VALUE(error_code)) - goto fault; - - offset_max = max(uaddr_from & ~PAGE_MASK, - uaddr_to & ~PAGE_MASK); - size = min(n - done, PAGE_SIZE - offset_max); - - memcpy((void *) kaddr_to, (void *) kaddr_from, size); - done += size; - uaddr_from += size; - uaddr_to += size; - } while (done < n); - spin_unlock(&mm->page_table_lock); - return n - done; -fault: - spin_unlock(&mm->page_table_lock); - if (__handle_fault(uaddr, -error_code, write_user)) - return n - done; - goto retry; -} - -#define __futex_atomic_op(insn, ret, oldval, newval, uaddr, oparg) \ - asm volatile("0: l %1,0(%6)\n" \ - "1: " insn \ - "2: cs %1,%2,0(%6)\n" \ - "3: jl 1b\n" \ - " lhi %0,0\n" \ - "4:\n" \ - EX_TABLE(0b,4b) EX_TABLE(2b,4b) EX_TABLE(3b,4b) \ - : "=d" (ret), "=&d" (oldval), "=&d" (newval), \ - "=m" (*uaddr) \ - : "0" (-EFAULT), "d" (oparg), "a" (uaddr), \ - "m" (*uaddr) : "cc" ); - -static int __futex_atomic_op_pt(int op, u32 __user *uaddr, int oparg, int *old) -{ - int oldval = 0, newval, ret; - - switch (op) { - case FUTEX_OP_SET: - __futex_atomic_op("lr %2,%5\n", - ret, oldval, newval, uaddr, oparg); - break; - case FUTEX_OP_ADD: - __futex_atomic_op("lr %2,%1\nar %2,%5\n", - ret, oldval, newval, uaddr, oparg); - break; - case FUTEX_OP_OR: - __futex_atomic_op("lr %2,%1\nor %2,%5\n", - ret, oldval, newval, uaddr, oparg); - break; - case FUTEX_OP_ANDN: - __futex_atomic_op("lr %2,%1\nnr %2,%5\n", - ret, oldval, newval, uaddr, oparg); - break; - case FUTEX_OP_XOR: - __futex_atomic_op("lr %2,%1\nxr %2,%5\n", - ret, oldval, newval, uaddr, oparg); - break; - default: - ret = -ENOSYS; - } - if (ret == 0) - *old = oldval; - return ret; -} - -int __futex_atomic_op_inuser(int op, u32 __user *uaddr, int oparg, int *old) -{ - int ret; - - if (segment_eq(get_fs(), KERNEL_DS)) - return __futex_atomic_op_pt(op, uaddr, oparg, old); - if (unlikely(!current->mm)) - return -EFAULT; - spin_lock(¤t->mm->page_table_lock); - uaddr = (u32 __force __user *) - __dat_user_addr((__force unsigned long) uaddr, 1); - if (!uaddr) { - spin_unlock(¤t->mm->page_table_lock); - return -EFAULT; - } - get_page(virt_to_page(uaddr)); - spin_unlock(¤t->mm->page_table_lock); - ret = __futex_atomic_op_pt(op, uaddr, oparg, old); - put_page(virt_to_page(uaddr)); - return ret; -} - -static int __futex_atomic_cmpxchg_pt(u32 *uval, u32 __user *uaddr, - u32 oldval, u32 newval) -{ - int ret; - - asm volatile("0: cs %1,%4,0(%5)\n" - "1: la %0,0\n" - "2:\n" - EX_TABLE(0b,2b) EX_TABLE(1b,2b) - : "=d" (ret), "+d" (oldval), "=m" (*uaddr) - : "0" (-EFAULT), "d" (newval), "a" (uaddr), "m" (*uaddr) - : "cc", "memory" ); - *uval = oldval; - return ret; -} - -int futex_atomic_cmpxchg_inatomic(u32 *uval, u32 __user *uaddr, - u32 oldval, u32 newval) -{ - int ret; - - if (segment_eq(get_fs(), KERNEL_DS)) - return __futex_atomic_cmpxchg_pt(uval, uaddr, oldval, newval); - if (unlikely(!current->mm)) - return -EFAULT; - spin_lock(¤t->mm->page_table_lock); - uaddr = (u32 __force __user *) - __dat_user_addr((__force unsigned long) uaddr, 1); - if (!uaddr) { - spin_unlock(¤t->mm->page_table_lock); - return -EFAULT; - } - get_page(virt_to_page(uaddr)); - spin_unlock(¤t->mm->page_table_lock); - ret = __futex_atomic_cmpxchg_pt(uval, uaddr, oldval, newval); - put_page(virt_to_page(uaddr)); - return ret; -} |