|
@@ -2,69 +2,82 @@
|
|
|
* User access functions based on page table walks for enhanced
|
|
|
* system layout without hardware support.
|
|
|
*
|
|
|
- * Copyright IBM Corp. 2006
|
|
|
+ * 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"
|
|
|
|
|
|
-static inline pte_t *follow_table(struct mm_struct *mm, unsigned long addr)
|
|
|
+
|
|
|
+/*
|
|
|
+ * Returns kernel address for user virtual address. If the returned address is
|
|
|
+ * >= -4095 (IS_ERR_VALUE(x) returns true), a fault has occured and the address
|
|
|
+ * contains the (negative) exception code.
|
|
|
+ */
|
|
|
+static __always_inline unsigned long follow_table(struct mm_struct *mm,
|
|
|
+ unsigned long addr, int write)
|
|
|
{
|
|
|
pgd_t *pgd;
|
|
|
pud_t *pud;
|
|
|
pmd_t *pmd;
|
|
|
+ pte_t *ptep;
|
|
|
|
|
|
pgd = pgd_offset(mm, addr);
|
|
|
if (pgd_none(*pgd) || unlikely(pgd_bad(*pgd)))
|
|
|
- return (pte_t *) 0x3a;
|
|
|
+ return -0x3aUL;
|
|
|
|
|
|
pud = pud_offset(pgd, addr);
|
|
|
if (pud_none(*pud) || unlikely(pud_bad(*pud)))
|
|
|
- return (pte_t *) 0x3b;
|
|
|
+ return -0x3bUL;
|
|
|
|
|
|
pmd = pmd_offset(pud, addr);
|
|
|
- if (pmd_none(*pmd) || unlikely(pmd_bad(*pmd)))
|
|
|
- return (pte_t *) 0x10;
|
|
|
+ if (pmd_none(*pmd))
|
|
|
+ return -0x10UL;
|
|
|
+ if (pmd_huge(*pmd)) {
|
|
|
+ if (write && (pmd_val(*pmd) & _SEGMENT_ENTRY_RO))
|
|
|
+ return -0x04UL;
|
|
|
+ return (pmd_val(*pmd) & HPAGE_MASK) + (addr & ~HPAGE_MASK);
|
|
|
+ }
|
|
|
+ if (unlikely(pmd_bad(*pmd)))
|
|
|
+ return -0x10UL;
|
|
|
+
|
|
|
+ ptep = pte_offset_map(pmd, addr);
|
|
|
+ if (!pte_present(*ptep))
|
|
|
+ return -0x11UL;
|
|
|
+ if (write && !pte_write(*ptep))
|
|
|
+ return -0x04UL;
|
|
|
|
|
|
- return pte_offset_map(pmd, addr);
|
|
|
+ return (pte_val(*ptep) & PAGE_MASK) + (addr & ~PAGE_MASK);
|
|
|
}
|
|
|
|
|
|
static __always_inline size_t __user_copy_pt(unsigned long uaddr, void *kptr,
|
|
|
size_t n, int write_user)
|
|
|
{
|
|
|
struct mm_struct *mm = current->mm;
|
|
|
- unsigned long offset, pfn, done, size;
|
|
|
- pte_t *pte;
|
|
|
+ unsigned long offset, done, size, kaddr;
|
|
|
void *from, *to;
|
|
|
|
|
|
done = 0;
|
|
|
retry:
|
|
|
spin_lock(&mm->page_table_lock);
|
|
|
do {
|
|
|
- pte = follow_table(mm, uaddr);
|
|
|
- if ((unsigned long) pte < 0x1000)
|
|
|
+ kaddr = follow_table(mm, uaddr, write_user);
|
|
|
+ if (IS_ERR_VALUE(kaddr))
|
|
|
goto fault;
|
|
|
- if (!pte_present(*pte)) {
|
|
|
- pte = (pte_t *) 0x11;
|
|
|
- goto fault;
|
|
|
- } else if (write_user && !pte_write(*pte)) {
|
|
|
- pte = (pte_t *) 0x04;
|
|
|
- goto fault;
|
|
|
- }
|
|
|
|
|
|
- pfn = pte_pfn(*pte);
|
|
|
- offset = uaddr & (PAGE_SIZE - 1);
|
|
|
+ offset = uaddr & ~PAGE_MASK;
|
|
|
size = min(n - done, PAGE_SIZE - offset);
|
|
|
if (write_user) {
|
|
|
- to = (void *)((pfn << PAGE_SHIFT) + offset);
|
|
|
+ to = (void *) kaddr;
|
|
|
from = kptr + done;
|
|
|
} else {
|
|
|
- from = (void *)((pfn << PAGE_SHIFT) + offset);
|
|
|
+ from = (void *) kaddr;
|
|
|
to = kptr + done;
|
|
|
}
|
|
|
memcpy(to, from, size);
|
|
@@ -75,7 +88,7 @@ retry:
|
|
|
return n - done;
|
|
|
fault:
|
|
|
spin_unlock(&mm->page_table_lock);
|
|
|
- if (__handle_fault(uaddr, (unsigned long) pte, write_user))
|
|
|
+ if (__handle_fault(uaddr, -kaddr, write_user))
|
|
|
return n - done;
|
|
|
goto retry;
|
|
|
}
|
|
@@ -84,27 +97,22 @@ fault:
|
|
|
* 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 __always_inline unsigned long __dat_user_addr(unsigned long uaddr)
|
|
|
+static __always_inline unsigned long __dat_user_addr(unsigned long uaddr,
|
|
|
+ int write)
|
|
|
{
|
|
|
struct mm_struct *mm = current->mm;
|
|
|
- unsigned long pfn;
|
|
|
- pte_t *pte;
|
|
|
+ unsigned long kaddr;
|
|
|
int rc;
|
|
|
|
|
|
retry:
|
|
|
- pte = follow_table(mm, uaddr);
|
|
|
- if ((unsigned long) pte < 0x1000)
|
|
|
- goto fault;
|
|
|
- if (!pte_present(*pte)) {
|
|
|
- pte = (pte_t *) 0x11;
|
|
|
+ kaddr = follow_table(mm, uaddr, write);
|
|
|
+ if (IS_ERR_VALUE(kaddr))
|
|
|
goto fault;
|
|
|
- }
|
|
|
|
|
|
- pfn = pte_pfn(*pte);
|
|
|
- return (pfn << PAGE_SHIFT) + (uaddr & (PAGE_SIZE - 1));
|
|
|
+ return kaddr;
|
|
|
fault:
|
|
|
spin_unlock(&mm->page_table_lock);
|
|
|
- rc = __handle_fault(uaddr, (unsigned long) pte, 0);
|
|
|
+ rc = __handle_fault(uaddr, -kaddr, write);
|
|
|
spin_lock(&mm->page_table_lock);
|
|
|
if (!rc)
|
|
|
goto retry;
|
|
@@ -159,11 +167,9 @@ static size_t clear_user_pt(size_t n, void __user *to)
|
|
|
|
|
|
static size_t strnlen_user_pt(size_t count, const char __user *src)
|
|
|
{
|
|
|
- char *addr;
|
|
|
unsigned long uaddr = (unsigned long) src;
|
|
|
struct mm_struct *mm = current->mm;
|
|
|
- unsigned long offset, pfn, done, len;
|
|
|
- pte_t *pte;
|
|
|
+ unsigned long offset, done, len, kaddr;
|
|
|
size_t len_str;
|
|
|
|
|
|
if (segment_eq(get_fs(), KERNEL_DS))
|
|
@@ -172,19 +178,13 @@ static size_t strnlen_user_pt(size_t count, const char __user *src)
|
|
|
retry:
|
|
|
spin_lock(&mm->page_table_lock);
|
|
|
do {
|
|
|
- pte = follow_table(mm, uaddr);
|
|
|
- if ((unsigned long) pte < 0x1000)
|
|
|
- goto fault;
|
|
|
- if (!pte_present(*pte)) {
|
|
|
- pte = (pte_t *) 0x11;
|
|
|
+ kaddr = follow_table(mm, uaddr, 0);
|
|
|
+ if (IS_ERR_VALUE(kaddr))
|
|
|
goto fault;
|
|
|
- }
|
|
|
|
|
|
- pfn = pte_pfn(*pte);
|
|
|
- offset = uaddr & (PAGE_SIZE-1);
|
|
|
- addr = (char *)(pfn << PAGE_SHIFT) + offset;
|
|
|
+ offset = uaddr & ~PAGE_MASK;
|
|
|
len = min(count - done, PAGE_SIZE - offset);
|
|
|
- len_str = strnlen(addr, len);
|
|
|
+ len_str = strnlen((char *) kaddr, len);
|
|
|
done += len_str;
|
|
|
uaddr += len_str;
|
|
|
} while ((len_str == len) && (done < count));
|
|
@@ -192,7 +192,7 @@ retry:
|
|
|
return done + 1;
|
|
|
fault:
|
|
|
spin_unlock(&mm->page_table_lock);
|
|
|
- if (__handle_fault(uaddr, (unsigned long) pte, 0))
|
|
|
+ if (__handle_fault(uaddr, -kaddr, 0))
|
|
|
return 0;
|
|
|
goto retry;
|
|
|
}
|
|
@@ -225,11 +225,10 @@ static size_t copy_in_user_pt(size_t n, void __user *to,
|
|
|
const void __user *from)
|
|
|
{
|
|
|
struct mm_struct *mm = current->mm;
|
|
|
- unsigned long offset_from, offset_to, offset_max, pfn_from, pfn_to,
|
|
|
- uaddr, done, size, error_code;
|
|
|
+ unsigned long offset_max, uaddr, done, size, error_code;
|
|
|
unsigned long uaddr_from = (unsigned long) from;
|
|
|
unsigned long uaddr_to = (unsigned long) to;
|
|
|
- pte_t *pte_from, *pte_to;
|
|
|
+ unsigned long kaddr_to, kaddr_from;
|
|
|
int write_user;
|
|
|
|
|
|
if (segment_eq(get_fs(), KERNEL_DS)) {
|
|
@@ -242,38 +241,23 @@ retry:
|
|
|
do {
|
|
|
write_user = 0;
|
|
|
uaddr = uaddr_from;
|
|
|
- pte_from = follow_table(mm, uaddr_from);
|
|
|
- error_code = (unsigned long) pte_from;
|
|
|
- if (error_code < 0x1000)
|
|
|
- goto fault;
|
|
|
- if (!pte_present(*pte_from)) {
|
|
|
- error_code = 0x11;
|
|
|
+ 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;
|
|
|
- pte_to = follow_table(mm, uaddr_to);
|
|
|
- error_code = (unsigned long) pte_to;
|
|
|
- if (error_code < 0x1000)
|
|
|
- goto fault;
|
|
|
- if (!pte_present(*pte_to)) {
|
|
|
- error_code = 0x11;
|
|
|
+ kaddr_to = follow_table(mm, uaddr_to, 1);
|
|
|
+ error_code = (unsigned long) kaddr_to;
|
|
|
+ if (IS_ERR_VALUE(error_code))
|
|
|
goto fault;
|
|
|
- } else if (!pte_write(*pte_to)) {
|
|
|
- error_code = 0x04;
|
|
|
- goto fault;
|
|
|
- }
|
|
|
|
|
|
- pfn_from = pte_pfn(*pte_from);
|
|
|
- pfn_to = pte_pfn(*pte_to);
|
|
|
- offset_from = uaddr_from & (PAGE_SIZE-1);
|
|
|
- offset_to = uaddr_from & (PAGE_SIZE-1);
|
|
|
- offset_max = max(offset_from, offset_to);
|
|
|
+ offset_max = max(uaddr_from & ~PAGE_MASK,
|
|
|
+ uaddr_to & ~PAGE_MASK);
|
|
|
size = min(n - done, PAGE_SIZE - offset_max);
|
|
|
|
|
|
- memcpy((void *)(pfn_to << PAGE_SHIFT) + offset_to,
|
|
|
- (void *)(pfn_from << PAGE_SHIFT) + offset_from, size);
|
|
|
+ memcpy((void *) kaddr_to, (void *) kaddr_from, size);
|
|
|
done += size;
|
|
|
uaddr_from += size;
|
|
|
uaddr_to += size;
|
|
@@ -282,7 +266,7 @@ retry:
|
|
|
return n - done;
|
|
|
fault:
|
|
|
spin_unlock(&mm->page_table_lock);
|
|
|
- if (__handle_fault(uaddr, error_code, write_user))
|
|
|
+ if (__handle_fault(uaddr, -error_code, write_user))
|
|
|
return n - done;
|
|
|
goto retry;
|
|
|
}
|
|
@@ -341,7 +325,7 @@ int futex_atomic_op_pt(int op, u32 __user *uaddr, int oparg, int *old)
|
|
|
return __futex_atomic_op_pt(op, uaddr, oparg, old);
|
|
|
spin_lock(¤t->mm->page_table_lock);
|
|
|
uaddr = (u32 __force __user *)
|
|
|
- __dat_user_addr((__force unsigned long) uaddr);
|
|
|
+ __dat_user_addr((__force unsigned long) uaddr, 1);
|
|
|
if (!uaddr) {
|
|
|
spin_unlock(¤t->mm->page_table_lock);
|
|
|
return -EFAULT;
|
|
@@ -378,7 +362,7 @@ int futex_atomic_cmpxchg_pt(u32 *uval, u32 __user *uaddr,
|
|
|
return __futex_atomic_cmpxchg_pt(uval, uaddr, oldval, newval);
|
|
|
spin_lock(¤t->mm->page_table_lock);
|
|
|
uaddr = (u32 __force __user *)
|
|
|
- __dat_user_addr((__force unsigned long) uaddr);
|
|
|
+ __dat_user_addr((__force unsigned long) uaddr, 1);
|
|
|
if (!uaddr) {
|
|
|
spin_unlock(¤t->mm->page_table_lock);
|
|
|
return -EFAULT;
|