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path: root/arch/s390/lib/uaccess_pt.c
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Diffstat (limited to 'arch/s390/lib/uaccess_pt.c')
-rw-r--r--arch/s390/lib/uaccess_pt.c59
1 files changed, 41 insertions, 18 deletions
diff --git a/arch/s390/lib/uaccess_pt.c b/arch/s390/lib/uaccess_pt.c
index 5efdfe9f5e7..d66215b0fde 100644
--- a/arch/s390/lib/uaccess_pt.c
+++ b/arch/s390/lib/uaccess_pt.c
@@ -302,6 +302,10 @@ static size_t copy_in_user_pt(size_t n, void __user *to,
pte_t *pte_from, *pte_to;
int write_user;
+ if (segment_eq(get_fs(), KERNEL_DS)) {
+ memcpy((void __force *) to, (void __force *) from, n);
+ return 0;
+ }
done = 0;
retry:
spin_lock(&mm->page_table_lock);
@@ -361,18 +365,10 @@ fault:
: "0" (-EFAULT), "d" (oparg), "a" (uaddr), \
"m" (*uaddr) : "cc" );
-int futex_atomic_op_pt(int op, int __user *uaddr, int oparg, int *old)
+static int __futex_atomic_op_pt(int op, int __user *uaddr, int oparg, int *old)
{
int oldval = 0, newval, ret;
- spin_lock(&current->mm->page_table_lock);
- uaddr = (int __user *) __dat_user_addr((unsigned long) uaddr);
- if (!uaddr) {
- spin_unlock(&current->mm->page_table_lock);
- return -EFAULT;
- }
- get_page(virt_to_page(uaddr));
- spin_unlock(&current->mm->page_table_lock);
switch (op) {
case FUTEX_OP_SET:
__futex_atomic_op("lr %2,%5\n",
@@ -397,17 +393,17 @@ int futex_atomic_op_pt(int op, int __user *uaddr, int oparg, int *old)
default:
ret = -ENOSYS;
}
- put_page(virt_to_page(uaddr));
- *old = oldval;
+ if (ret == 0)
+ *old = oldval;
return ret;
}
-int futex_atomic_cmpxchg_pt(int __user *uaddr, int oldval, int newval)
+int futex_atomic_op_pt(int op, int __user *uaddr, int oparg, int *old)
{
int ret;
- if (!current->mm)
- return -EFAULT;
+ if (segment_eq(get_fs(), KERNEL_DS))
+ return __futex_atomic_op_pt(op, uaddr, oparg, old);
spin_lock(&current->mm->page_table_lock);
uaddr = (int __user *) __dat_user_addr((unsigned long) uaddr);
if (!uaddr) {
@@ -416,13 +412,40 @@ int futex_atomic_cmpxchg_pt(int __user *uaddr, int oldval, int newval)
}
get_page(virt_to_page(uaddr));
spin_unlock(&current->mm->page_table_lock);
- asm volatile(" cs %1,%4,0(%5)\n"
- "0: lr %0,%1\n"
- "1:\n"
- EX_TABLE(0b,1b)
+ ret = __futex_atomic_op_pt(op, uaddr, oparg, old);
+ put_page(virt_to_page(uaddr));
+ return ret;
+}
+
+static int __futex_atomic_cmpxchg_pt(int __user *uaddr, int oldval, int newval)
+{
+ int ret;
+
+ asm volatile("0: cs %1,%4,0(%5)\n"
+ "1: lr %0,%1\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" );
+ return ret;
+}
+
+int futex_atomic_cmpxchg_pt(int __user *uaddr, int oldval, int newval)
+{
+ int ret;
+
+ if (segment_eq(get_fs(), KERNEL_DS))
+ return __futex_atomic_cmpxchg_pt(uaddr, oldval, newval);
+ spin_lock(&current->mm->page_table_lock);
+ uaddr = (int __user *) __dat_user_addr((unsigned long) uaddr);
+ if (!uaddr) {
+ spin_unlock(&current->mm->page_table_lock);
+ return -EFAULT;
+ }
+ get_page(virt_to_page(uaddr));
+ spin_unlock(&current->mm->page_table_lock);
+ ret = __futex_atomic_cmpxchg_pt(uaddr, oldval, newval);
put_page(virt_to_page(uaddr));
return ret;
}