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linux-next/arch/x86/include/asm/futex.h
Al Viro a08971e948 futex: arch_futex_atomic_op_inuser() calling conventions change
Move access_ok() in and pagefault_enable()/pagefault_disable() out.
Mechanical conversion only - some instances don't really need
a separate access_ok() at all (e.g. the ones only using
get_user()/put_user(), or architectures where access_ok()
is always true); we'll deal with that in followups.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2020-03-27 23:58:51 -04:00

88 lines
2.2 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 __futex_atomic_op1(insn, ret, oldval, uaddr, oparg) \
asm volatile("\t" ASM_STAC "\n" \
"1:\t" insn "\n" \
"2:\t" ASM_CLAC "\n" \
"\t.section .fixup,\"ax\"\n" \
"3:\tmov\t%3, %1\n" \
"\tjmp\t2b\n" \
"\t.previous\n" \
_ASM_EXTABLE_UA(1b, 3b) \
: "=r" (oldval), "=r" (ret), "+m" (*uaddr) \
: "i" (-EFAULT), "0" (oparg), "1" (0))
#define __futex_atomic_op2(insn, ret, oldval, uaddr, oparg) \
asm volatile("\t" ASM_STAC "\n" \
"1:\tmovl %2, %0\n" \
"\tmovl\t%0, %3\n" \
"\t" insn "\n" \
"2:\t" LOCK_PREFIX "cmpxchgl %3, %2\n" \
"\tjnz\t1b\n" \
"3:\t" ASM_CLAC "\n" \
"\t.section .fixup,\"ax\"\n" \
"4:\tmov\t%5, %1\n" \
"\tjmp\t3b\n" \
"\t.previous\n" \
_ASM_EXTABLE_UA(1b, 4b) \
_ASM_EXTABLE_UA(2b, 4b) \
: "=&a" (oldval), "=&r" (ret), \
"+m" (*uaddr), "=&r" (tem) \
: "r" (oparg), "i" (-EFAULT), "1" (0))
static inline int arch_futex_atomic_op_inuser(int op, int oparg, int *oval,
u32 __user *uaddr)
{
int oldval = 0, ret, tem;
if (!access_ok(uaddr, sizeof(u32)))
return -EFAULT;
switch (op) {
case FUTEX_OP_SET:
__futex_atomic_op1("xchgl %0, %2", ret, oldval, uaddr, oparg);
break;
case FUTEX_OP_ADD:
__futex_atomic_op1(LOCK_PREFIX "xaddl %0, %2", ret, oldval,
uaddr, oparg);
break;
case FUTEX_OP_OR:
__futex_atomic_op2("orl %4, %3", ret, oldval, uaddr, oparg);
break;
case FUTEX_OP_ANDN:
__futex_atomic_op2("andl %4, %3", ret, oldval, uaddr, ~oparg);
break;
case FUTEX_OP_XOR:
__futex_atomic_op2("xorl %4, %3", ret, oldval, uaddr, oparg);
break;
default:
ret = -ENOSYS;
}
if (!ret)
*oval = oldval;
return ret;
}
static inline int futex_atomic_cmpxchg_inatomic(u32 *uval, u32 __user *uaddr,
u32 oldval, u32 newval)
{
return user_atomic_cmpxchg_inatomic(uval, uaddr, oldval, newval);
}
#endif
#endif /* _ASM_X86_FUTEX_H */