diff options
| -rw-r--r-- | arch/s390/lib/uaccess_pt.c | 59 |
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(¤t->mm->page_table_lock); - uaddr = (int __user *) __dat_user_addr((unsigned long) uaddr); - if (!uaddr) { - spin_unlock(¤t->mm->page_table_lock); - return -EFAULT; - } - get_page(virt_to_page(uaddr)); - spin_unlock(¤t->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(¤t->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(¤t->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(¤t->mm->page_table_lock); + uaddr = (int __user *) __dat_user_addr((unsigned long) uaddr); + 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(uaddr, oldval, newval); put_page(virt_to_page(uaddr)); return ret; } |