summaryrefslogtreecommitdiff
path: root/kernel/futex/futex.h
diff options
context:
space:
mode:
Diffstat (limited to 'kernel/futex/futex.h')
-rw-r--r--kernel/futex/futex.h58
1 files changed, 3 insertions, 55 deletions
diff --git a/kernel/futex/futex.h b/kernel/futex/futex.h
index 2cd57096c38e..30c2afa03889 100644
--- a/kernel/futex/futex.h
+++ b/kernel/futex/futex.h
@@ -281,63 +281,11 @@ static inline int futex_cmpxchg_value_locked(u32 *curval, u32 __user *uaddr, u32
return ret;
}
-/*
- * This does a plain atomic user space read, and the user pointer has
- * already been verified earlier by get_futex_key() to be both aligned
- * and actually in user space, just like futex_atomic_cmpxchg_inatomic().
- *
- * We still want to avoid any speculation, and while __get_user() is
- * the traditional model for this, it's actually slower than doing
- * this manually these days.
- *
- * We could just have a per-architecture special function for it,
- * the same way we do futex_atomic_cmpxchg_inatomic(), but rather
- * than force everybody to do that, write it out long-hand using
- * the low-level user-access infrastructure.
- *
- * This looks a bit overkill, but generally just results in a couple
- * of instructions.
- */
-static __always_inline int futex_get_value(u32 *dest, u32 __user *from)
-{
- u32 val;
-
- if (can_do_masked_user_access())
- from = masked_user_access_begin(from);
- else if (!user_read_access_begin(from, sizeof(*from)))
- return -EFAULT;
- unsafe_get_user(val, from, Efault);
- user_read_access_end();
- *dest = val;
- return 0;
-Efault:
- user_read_access_end();
- return -EFAULT;
-}
-
-static __always_inline int futex_put_value(u32 val, u32 __user *to)
-{
- if (can_do_masked_user_access())
- to = masked_user_access_begin(to);
- else if (!user_write_access_begin(to, sizeof(*to)))
- return -EFAULT;
- unsafe_put_user(val, to, Efault);
- user_write_access_end();
- return 0;
-Efault:
- user_write_access_end();
- return -EFAULT;
-}
-
+/* Read from user memory with pagefaults disabled */
static inline int futex_get_value_locked(u32 *dest, u32 __user *from)
{
- int ret;
-
- pagefault_disable();
- ret = futex_get_value(dest, from);
- pagefault_enable();
-
- return ret;
+ guard(pagefault)();
+ return get_user_inline(*dest, from);
}
extern void __futex_unqueue(struct futex_q *q);