243 lines
6.6 KiB
C
243 lines
6.6 KiB
C
/* futex.c: futex operations
|
|
*
|
|
* Copyright (C) 2005 Red Hat, Inc. All Rights Reserved.
|
|
* Written by David Howells (dhowells@redhat.com)
|
|
*
|
|
* This program is free software; you can redistribute it and/or
|
|
* modify it under the terms of the GNU General Public License
|
|
* as published by the Free Software Foundation; either version
|
|
* 2 of the License, or (at your option) any later version.
|
|
*/
|
|
|
|
#include <linux/futex.h>
|
|
#include <linux/uaccess.h>
|
|
#include <asm/futex.h>
|
|
#include <asm/errno.h>
|
|
|
|
/*
|
|
* the various futex operations; MMU fault checking is ignored under no-MMU
|
|
* conditions
|
|
*/
|
|
static inline int atomic_futex_op_xchg_set(int oparg, int __user *uaddr, int *_oldval)
|
|
{
|
|
int oldval, ret;
|
|
|
|
asm("0: \n"
|
|
" orcc gr0,gr0,gr0,icc3 \n" /* set ICC3.Z */
|
|
" ckeq icc3,cc7 \n"
|
|
"1: ld.p %M0,%1 \n" /* LD.P/ORCR must be atomic */
|
|
" orcr cc7,cc7,cc3 \n" /* set CC3 to true */
|
|
"2: cst.p %3,%M0 ,cc3,#1 \n"
|
|
" corcc gr29,gr29,gr0 ,cc3,#1 \n" /* clear ICC3.Z if store happens */
|
|
" beq icc3,#0,0b \n"
|
|
" setlos 0,%2 \n"
|
|
"3: \n"
|
|
".subsection 2 \n"
|
|
"4: setlos %5,%2 \n"
|
|
" bra 3b \n"
|
|
".previous \n"
|
|
".section __ex_table,\"a\" \n"
|
|
" .balign 8 \n"
|
|
" .long 1b,4b \n"
|
|
" .long 2b,4b \n"
|
|
".previous"
|
|
: "+U"(*uaddr), "=&r"(oldval), "=&r"(ret), "=r"(oparg)
|
|
: "3"(oparg), "i"(-EFAULT)
|
|
: "memory", "cc7", "cc3", "icc3"
|
|
);
|
|
|
|
*_oldval = oldval;
|
|
return ret;
|
|
}
|
|
|
|
static inline int atomic_futex_op_xchg_add(int oparg, int __user *uaddr, int *_oldval)
|
|
{
|
|
int oldval, ret;
|
|
|
|
asm("0: \n"
|
|
" orcc gr0,gr0,gr0,icc3 \n" /* set ICC3.Z */
|
|
" ckeq icc3,cc7 \n"
|
|
"1: ld.p %M0,%1 \n" /* LD.P/ORCR must be atomic */
|
|
" orcr cc7,cc7,cc3 \n" /* set CC3 to true */
|
|
" add %1,%3,%3 \n"
|
|
"2: cst.p %3,%M0 ,cc3,#1 \n"
|
|
" corcc gr29,gr29,gr0 ,cc3,#1 \n" /* clear ICC3.Z if store happens */
|
|
" beq icc3,#0,0b \n"
|
|
" setlos 0,%2 \n"
|
|
"3: \n"
|
|
".subsection 2 \n"
|
|
"4: setlos %5,%2 \n"
|
|
" bra 3b \n"
|
|
".previous \n"
|
|
".section __ex_table,\"a\" \n"
|
|
" .balign 8 \n"
|
|
" .long 1b,4b \n"
|
|
" .long 2b,4b \n"
|
|
".previous"
|
|
: "+U"(*uaddr), "=&r"(oldval), "=&r"(ret), "=r"(oparg)
|
|
: "3"(oparg), "i"(-EFAULT)
|
|
: "memory", "cc7", "cc3", "icc3"
|
|
);
|
|
|
|
*_oldval = oldval;
|
|
return ret;
|
|
}
|
|
|
|
static inline int atomic_futex_op_xchg_or(int oparg, int __user *uaddr, int *_oldval)
|
|
{
|
|
int oldval, ret;
|
|
|
|
asm("0: \n"
|
|
" orcc gr0,gr0,gr0,icc3 \n" /* set ICC3.Z */
|
|
" ckeq icc3,cc7 \n"
|
|
"1: ld.p %M0,%1 \n" /* LD.P/ORCR must be atomic */
|
|
" orcr cc7,cc7,cc3 \n" /* set CC3 to true */
|
|
" or %1,%3,%3 \n"
|
|
"2: cst.p %3,%M0 ,cc3,#1 \n"
|
|
" corcc gr29,gr29,gr0 ,cc3,#1 \n" /* clear ICC3.Z if store happens */
|
|
" beq icc3,#0,0b \n"
|
|
" setlos 0,%2 \n"
|
|
"3: \n"
|
|
".subsection 2 \n"
|
|
"4: setlos %5,%2 \n"
|
|
" bra 3b \n"
|
|
".previous \n"
|
|
".section __ex_table,\"a\" \n"
|
|
" .balign 8 \n"
|
|
" .long 1b,4b \n"
|
|
" .long 2b,4b \n"
|
|
".previous"
|
|
: "+U"(*uaddr), "=&r"(oldval), "=&r"(ret), "=r"(oparg)
|
|
: "3"(oparg), "i"(-EFAULT)
|
|
: "memory", "cc7", "cc3", "icc3"
|
|
);
|
|
|
|
*_oldval = oldval;
|
|
return ret;
|
|
}
|
|
|
|
static inline int atomic_futex_op_xchg_and(int oparg, int __user *uaddr, int *_oldval)
|
|
{
|
|
int oldval, ret;
|
|
|
|
asm("0: \n"
|
|
" orcc gr0,gr0,gr0,icc3 \n" /* set ICC3.Z */
|
|
" ckeq icc3,cc7 \n"
|
|
"1: ld.p %M0,%1 \n" /* LD.P/ORCR must be atomic */
|
|
" orcr cc7,cc7,cc3 \n" /* set CC3 to true */
|
|
" and %1,%3,%3 \n"
|
|
"2: cst.p %3,%M0 ,cc3,#1 \n"
|
|
" corcc gr29,gr29,gr0 ,cc3,#1 \n" /* clear ICC3.Z if store happens */
|
|
" beq icc3,#0,0b \n"
|
|
" setlos 0,%2 \n"
|
|
"3: \n"
|
|
".subsection 2 \n"
|
|
"4: setlos %5,%2 \n"
|
|
" bra 3b \n"
|
|
".previous \n"
|
|
".section __ex_table,\"a\" \n"
|
|
" .balign 8 \n"
|
|
" .long 1b,4b \n"
|
|
" .long 2b,4b \n"
|
|
".previous"
|
|
: "+U"(*uaddr), "=&r"(oldval), "=&r"(ret), "=r"(oparg)
|
|
: "3"(oparg), "i"(-EFAULT)
|
|
: "memory", "cc7", "cc3", "icc3"
|
|
);
|
|
|
|
*_oldval = oldval;
|
|
return ret;
|
|
}
|
|
|
|
static inline int atomic_futex_op_xchg_xor(int oparg, int __user *uaddr, int *_oldval)
|
|
{
|
|
int oldval, ret;
|
|
|
|
asm("0: \n"
|
|
" orcc gr0,gr0,gr0,icc3 \n" /* set ICC3.Z */
|
|
" ckeq icc3,cc7 \n"
|
|
"1: ld.p %M0,%1 \n" /* LD.P/ORCR must be atomic */
|
|
" orcr cc7,cc7,cc3 \n" /* set CC3 to true */
|
|
" xor %1,%3,%3 \n"
|
|
"2: cst.p %3,%M0 ,cc3,#1 \n"
|
|
" corcc gr29,gr29,gr0 ,cc3,#1 \n" /* clear ICC3.Z if store happens */
|
|
" beq icc3,#0,0b \n"
|
|
" setlos 0,%2 \n"
|
|
"3: \n"
|
|
".subsection 2 \n"
|
|
"4: setlos %5,%2 \n"
|
|
" bra 3b \n"
|
|
".previous \n"
|
|
".section __ex_table,\"a\" \n"
|
|
" .balign 8 \n"
|
|
" .long 1b,4b \n"
|
|
" .long 2b,4b \n"
|
|
".previous"
|
|
: "+U"(*uaddr), "=&r"(oldval), "=&r"(ret), "=r"(oparg)
|
|
: "3"(oparg), "i"(-EFAULT)
|
|
: "memory", "cc7", "cc3", "icc3"
|
|
);
|
|
|
|
*_oldval = oldval;
|
|
return ret;
|
|
}
|
|
|
|
/*****************************************************************************/
|
|
/*
|
|
* do the futex operations
|
|
*/
|
|
int futex_atomic_op_inuser(int encoded_op, int __user *uaddr)
|
|
{
|
|
int op = (encoded_op >> 28) & 7;
|
|
int cmp = (encoded_op >> 24) & 15;
|
|
int oparg = (encoded_op << 8) >> 20;
|
|
int cmparg = (encoded_op << 20) >> 20;
|
|
int oldval = 0, ret;
|
|
|
|
if (encoded_op & (FUTEX_OP_OPARG_SHIFT << 28))
|
|
oparg = 1 << oparg;
|
|
|
|
if (!access_ok(VERIFY_WRITE, uaddr, sizeof(int)))
|
|
return -EFAULT;
|
|
|
|
pagefault_disable();
|
|
|
|
switch (op) {
|
|
case FUTEX_OP_SET:
|
|
ret = atomic_futex_op_xchg_set(oparg, uaddr, &oldval);
|
|
break;
|
|
case FUTEX_OP_ADD:
|
|
ret = atomic_futex_op_xchg_add(oparg, uaddr, &oldval);
|
|
break;
|
|
case FUTEX_OP_OR:
|
|
ret = atomic_futex_op_xchg_or(oparg, uaddr, &oldval);
|
|
break;
|
|
case FUTEX_OP_ANDN:
|
|
ret = atomic_futex_op_xchg_and(~oparg, uaddr, &oldval);
|
|
break;
|
|
case FUTEX_OP_XOR:
|
|
ret = atomic_futex_op_xchg_xor(oparg, uaddr, &oldval);
|
|
break;
|
|
default:
|
|
ret = -ENOSYS;
|
|
break;
|
|
}
|
|
|
|
pagefault_enable();
|
|
|
|
if (!ret) {
|
|
switch (cmp) {
|
|
case FUTEX_OP_CMP_EQ: ret = (oldval == cmparg); break;
|
|
case FUTEX_OP_CMP_NE: ret = (oldval != cmparg); break;
|
|
case FUTEX_OP_CMP_LT: ret = (oldval < cmparg); break;
|
|
case FUTEX_OP_CMP_GE: ret = (oldval >= cmparg); break;
|
|
case FUTEX_OP_CMP_LE: ret = (oldval <= cmparg); break;
|
|
case FUTEX_OP_CMP_GT: ret = (oldval > cmparg); break;
|
|
default: ret = -ENOSYS; break;
|
|
}
|
|
}
|
|
|
|
return ret;
|
|
|
|
} /* end futex_atomic_op_inuser() */
|