linux/arch/um/include/asm/futex.h

/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _ASM_UM_FUTEX_H
#define _ASM_UM_FUTEX_H

#include <linux/futex.h>
#include <linux/uaccess.h>
#include <asm/errno.h>


int arch_futex_atomic_op_inuser(int op, u32 oparg, int *oval, u32 __user *uaddr);
int futex_atomic_cmpxchg_inatomic(u32 *uval, u32 __user *uaddr,
			      u32 oldval, u32 newval);

#endif
um: add a UML specific futex implementation The generic asm futex implementation emulates atomic access to memory by doing a get_user followed by put_user. These translate to two mapping operations on UML with paging enabled in the meantime. This, in turn may end up changing interrupts, invoking the signal loop, etc. This replaces the generic implementation by a mapping followed by an operation on the mapped segment. Signed-off-by: Anton Ivanov <anton.ivanov@cambridgegreys.com> Signed-off-by: Richard Weinberger <richard@nod.at> 2021-03-12 15:16:09 +00:00			`/* SPDX-License-Identifier: GPL-2.0 */`
			`#ifndef _ASM_UM_FUTEX_H`
			`#define _ASM_UM_FUTEX_H`

			`#include <linux/futex.h>`
			`#include <linux/uaccess.h>`
			`#include <asm/errno.h>`


			`int arch_futex_atomic_op_inuser(int op, u32 oparg, int oval, u32 __user uaddr);`
			`int futex_atomic_cmpxchg_inatomic(u32 uval, u32 __user uaddr,`
			`u32 oldval, u32 newval);`

			`#endif`