104 lines
2.5 KiB
C
104 lines
2.5 KiB
C
/* SPDX-License-Identifier: GPL-2.0 */
|
|
#ifndef _ASM_X86_FUTEX_H
|
|
#define _ASM_X86_FUTEX_H
|
|
|
|
#ifdef __KERNEL__
|
|
|
|
#include <linux/futex.h>
|
|
#include <linux/uaccess.h>
|
|
|
|
#include <asm/asm.h>
|
|
#include <asm/errno.h>
|
|
#include <asm/processor.h>
|
|
#include <asm/smap.h>
|
|
|
|
#define unsafe_atomic_op1(insn, oval, uaddr, oparg, label) \
|
|
do { \
|
|
int oldval = 0, ret; \
|
|
asm volatile("1:\t" insn "\n" \
|
|
"2:\n" \
|
|
_ASM_EXTABLE_TYPE_REG(1b, 2b, EX_TYPE_EFAULT_REG, %1) \
|
|
: "=r" (oldval), "=r" (ret), "+m" (*uaddr) \
|
|
: "0" (oparg), "1" (0)); \
|
|
if (ret) \
|
|
goto label; \
|
|
*oval = oldval; \
|
|
} while(0)
|
|
|
|
|
|
#define unsafe_atomic_op2(insn, oval, uaddr, oparg, label) \
|
|
do { \
|
|
int oldval = 0, ret, tem; \
|
|
asm volatile("1:\tmovl %2, %0\n" \
|
|
"2:\tmovl\t%0, %3\n" \
|
|
"\t" insn "\n" \
|
|
"3:\t" LOCK_PREFIX "cmpxchgl %3, %2\n" \
|
|
"\tjnz\t2b\n" \
|
|
"4:\n" \
|
|
_ASM_EXTABLE_TYPE_REG(1b, 4b, EX_TYPE_EFAULT_REG, %1) \
|
|
_ASM_EXTABLE_TYPE_REG(3b, 4b, EX_TYPE_EFAULT_REG, %1) \
|
|
: "=&a" (oldval), "=&r" (ret), \
|
|
"+m" (*uaddr), "=&r" (tem) \
|
|
: "r" (oparg), "1" (0)); \
|
|
if (ret) \
|
|
goto label; \
|
|
*oval = oldval; \
|
|
} while(0)
|
|
|
|
static __always_inline int arch_futex_atomic_op_inuser(int op, int oparg, int *oval,
|
|
u32 __user *uaddr)
|
|
{
|
|
if (!user_access_begin(uaddr, sizeof(u32)))
|
|
return -EFAULT;
|
|
|
|
switch (op) {
|
|
case FUTEX_OP_SET:
|
|
unsafe_atomic_op1("xchgl %0, %2", oval, uaddr, oparg, Efault);
|
|
break;
|
|
case FUTEX_OP_ADD:
|
|
unsafe_atomic_op1(LOCK_PREFIX "xaddl %0, %2", oval,
|
|
uaddr, oparg, Efault);
|
|
break;
|
|
case FUTEX_OP_OR:
|
|
unsafe_atomic_op2("orl %4, %3", oval, uaddr, oparg, Efault);
|
|
break;
|
|
case FUTEX_OP_ANDN:
|
|
unsafe_atomic_op2("andl %4, %3", oval, uaddr, ~oparg, Efault);
|
|
break;
|
|
case FUTEX_OP_XOR:
|
|
unsafe_atomic_op2("xorl %4, %3", oval, uaddr, oparg, Efault);
|
|
break;
|
|
default:
|
|
user_access_end();
|
|
return -ENOSYS;
|
|
}
|
|
user_access_end();
|
|
return 0;
|
|
Efault:
|
|
user_access_end();
|
|
return -EFAULT;
|
|
}
|
|
|
|
static inline int futex_atomic_cmpxchg_inatomic(u32 *uval, u32 __user *uaddr,
|
|
u32 oldval, u32 newval)
|
|
{
|
|
int ret = 0;
|
|
|
|
if (!user_access_begin(uaddr, sizeof(u32)))
|
|
return -EFAULT;
|
|
asm volatile("\n"
|
|
"1:\t" LOCK_PREFIX "cmpxchgl %3, %2\n"
|
|
"2:\n"
|
|
_ASM_EXTABLE_TYPE_REG(1b, 2b, EX_TYPE_EFAULT_REG, %0) \
|
|
: "+r" (ret), "=a" (oldval), "+m" (*uaddr)
|
|
: "r" (newval), "1" (oldval)
|
|
: "memory"
|
|
);
|
|
user_access_end();
|
|
*uval = oldval;
|
|
return ret;
|
|
}
|
|
|
|
#endif
|
|
#endif /* _ASM_X86_FUTEX_H */
|