mirror of
https://github.com/edk2-porting/linux-next.git
synced 2024-12-17 17:53:56 +08:00
2de0db992d
sys_futex() is a wrapper to do_futex() which does not modify any values here: - uaddr, val and val3 are kept the same - op is masked with FUTEX_CMD_MASK, but is always set to FUTEX_WAKE. Therefore, val2 is always 0. - as utime is set to NULL, *timeout is NULL This patch is part of a series which removes in-kernel calls to syscalls. On this basis, the syscall entry path can be streamlined. For details, see http://lkml.kernel.org/r/20180325162527.GA17492@light.dominikbrodowski.net Cc: Ingo Molnar <mingo@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Darren Hart <dvhart@infradead.org> Cc: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Dominik Brodowski <linux@dominikbrodowski.net>
85 lines
2.1 KiB
C
85 lines
2.1 KiB
C
/* SPDX-License-Identifier: GPL-2.0 */
|
|
#ifndef _LINUX_FUTEX_H
|
|
#define _LINUX_FUTEX_H
|
|
|
|
#include <linux/ktime.h>
|
|
#include <uapi/linux/futex.h>
|
|
|
|
struct inode;
|
|
struct mm_struct;
|
|
struct task_struct;
|
|
|
|
extern int
|
|
handle_futex_death(u32 __user *uaddr, struct task_struct *curr, int pi);
|
|
|
|
/*
|
|
* Futexes are matched on equal values of this key.
|
|
* The key type depends on whether it's a shared or private mapping.
|
|
* Don't rearrange members without looking at hash_futex().
|
|
*
|
|
* offset is aligned to a multiple of sizeof(u32) (== 4) by definition.
|
|
* We use the two low order bits of offset to tell what is the kind of key :
|
|
* 00 : Private process futex (PTHREAD_PROCESS_PRIVATE)
|
|
* (no reference on an inode or mm)
|
|
* 01 : Shared futex (PTHREAD_PROCESS_SHARED)
|
|
* mapped on a file (reference on the underlying inode)
|
|
* 10 : Shared futex (PTHREAD_PROCESS_SHARED)
|
|
* (but private mapping on an mm, and reference taken on it)
|
|
*/
|
|
|
|
#define FUT_OFF_INODE 1 /* We set bit 0 if key has a reference on inode */
|
|
#define FUT_OFF_MMSHARED 2 /* We set bit 1 if key has a reference on mm */
|
|
|
|
union futex_key {
|
|
struct {
|
|
unsigned long pgoff;
|
|
struct inode *inode;
|
|
int offset;
|
|
} shared;
|
|
struct {
|
|
unsigned long address;
|
|
struct mm_struct *mm;
|
|
int offset;
|
|
} private;
|
|
struct {
|
|
unsigned long word;
|
|
void *ptr;
|
|
int offset;
|
|
} both;
|
|
};
|
|
|
|
#define FUTEX_KEY_INIT (union futex_key) { .both = { .ptr = NULL } }
|
|
|
|
#ifdef CONFIG_FUTEX
|
|
extern void exit_robust_list(struct task_struct *curr);
|
|
|
|
long do_futex(u32 __user *uaddr, int op, u32 val, ktime_t *timeout,
|
|
u32 __user *uaddr2, u32 val2, u32 val3);
|
|
#ifdef CONFIG_HAVE_FUTEX_CMPXCHG
|
|
#define futex_cmpxchg_enabled 1
|
|
#else
|
|
extern int futex_cmpxchg_enabled;
|
|
#endif
|
|
#else
|
|
static inline void exit_robust_list(struct task_struct *curr)
|
|
{
|
|
}
|
|
|
|
static inline long do_futex(u32 __user *uaddr, int op, u32 val,
|
|
ktime_t *timeout, u32 __user *uaddr2,
|
|
u32 val2, u32 val3)
|
|
{
|
|
return -EINVAL;
|
|
}
|
|
#endif
|
|
|
|
#ifdef CONFIG_FUTEX_PI
|
|
extern void exit_pi_state_list(struct task_struct *curr);
|
|
#else
|
|
static inline void exit_pi_state_list(struct task_struct *curr)
|
|
{
|
|
}
|
|
#endif
|
|
|
|
#endif
|