+++ /dev/null
-/*
- * 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;
-}
projects / linux.git / blobdiff