[PATCH -mm] 64bit-futex - provide new commands instead of new syscall

From: Pierre Peiffer
Date: Mon Apr 23 2007 - 10:38:48 EST

Hi,

Jakub Jelinek a écrit :

I don't think you should blindly add all operations to sys_futex64 without
thinking what they really do.
E.g. FUTEX_{{,UN,TRY}LOCK,CMP_REQUEUE}_PI doesn't really make any sense for 64-bit
futexes, the format of PI futexes is hardcoded in the kernel and is always
32-bit, see FUTEX_TID_MASK, FUTEX_WAITERS, FUTEX_OWNER_DIED definitions.
exit_robust_list/handle_futex_death will handle 32-bit PI futexes anyway.
Similarly, sys_futex64 shouldn't support the obsolete operations that
are there solely for compatibility (e.g. FUTEX_REQUEUE or FUTEX_FD).

When you just -ENOSYS on the PI ops, there is no need to implement
futex_atomic_cmpxchg_inatomic64.

FUTEX_WAKE_OP is questionable for 64-bit, IMHO it is better to just
-ENOSYS on it and only if anyone ever finds actual uses for it, add it.

For 64-bit futexes the only needed operations are actually
FUTEX_WAIT and perhaps FUTEX_CMP_REQUEUE, so I wonder if it isn't
better to just add FUTEX_WAIT64 and FUTEX_CMP_REQUEUE64 ops to sys_futex
instead of adding a new syscall.

But the FUTEX_{{,UN,TRY}LOCK,CMP_REQUEUE}_PI removal for 64-bit futexes
is IMHO the most important part of my complain.


Following this mail sent few weeks ago, here is a patch which should meet your requirements.
I've quickly done it on top of the latest -mm (2.6.21-rc6-mm2) and a little bit tested.
To be honest, as I'm not really aware of your exact needs and as I don't know the exact usage which will be done with 64bit futexes, I can't really maintain it. So I'll let you take/modify/adapt this patch following your needs.

Thanks,

Signed-off-by: Pierre Peiffer <pierre.peiffer@xxxxxxxx>



--
Pierre
---
include/asm-ia64/futex.h | 8 -
include/asm-powerpc/futex.h | 6 -
include/asm-s390/futex.h | 8 -
include/asm-sparc64/futex.h | 8 -
include/asm-um/futex.h | 9 -
include/asm-x86_64/futex.h | 86 -------------------
include/asm-x86_64/unistd.h | 2
include/linux/futex.h | 8 +
include/linux/syscalls.h | 3
kernel/futex.c | 199 +++++++++++++++++---------------------------
kernel/futex_compat.c | 2
kernel/sys_ni.c | 1
12 files changed, 93 insertions(+), 247 deletions(-)

Index: linux-2.6.21-rc6-mm2/include/asm-ia64/futex.h
===================================================================
--- linux-2.6.21-rc6-mm2.orig/include/asm-ia64/futex.h 2007-04-20 14:01:25.000000000 +0200
+++ linux-2.6.21-rc6-mm2/include/asm-ia64/futex.h 2007-04-20 13:50:00.000000000 +0200
@@ -124,13 +124,7 @@ futex_atomic_cmpxchg_inatomic(int __user
static inline u64
futex_atomic_cmpxchg_inatomic64(u64 __user *uaddr, u64 oldval, u64 newval)
{
- return 0;
-}
-
-static inline int
-futex_atomic_op_inuser64 (int encoded_op, u64 __user *uaddr)
-{
- return 0;
+ return -ENOSYS;
}

#endif /* _ASM_FUTEX_H */
Index: linux-2.6.21-rc6-mm2/include/asm-powerpc/futex.h
===================================================================
--- linux-2.6.21-rc6-mm2.orig/include/asm-powerpc/futex.h 2007-04-20 14:01:25.000000000 +0200
+++ linux-2.6.21-rc6-mm2/include/asm-powerpc/futex.h 2007-04-20 13:51:49.000000000 +0200
@@ -119,11 +119,5 @@ futex_atomic_cmpxchg_inatomic64(u64 __us
return 0;
}

-static inline int
-futex_atomic_op_inuser64 (int encoded_op, u64 __user *uaddr)
-{
- return 0;
-}
-
#endif /* __KERNEL__ */
#endif /* _ASM_POWERPC_FUTEX_H */
Index: linux-2.6.21-rc6-mm2/include/asm-s390/futex.h
===================================================================
--- linux-2.6.21-rc6-mm2.orig/include/asm-s390/futex.h 2007-04-20 14:01:24.000000000 +0200
+++ linux-2.6.21-rc6-mm2/include/asm-s390/futex.h 2007-04-20 13:47:30.000000000 +0200
@@ -51,13 +51,7 @@ static inline int futex_atomic_cmpxchg_i
static inline u64
futex_atomic_cmpxchg_inatomic64(u64 __user *uaddr, u64 oldval, u64 newval)
{
- return 0;
-}
-
-static inline int
-futex_atomic_op_inuser64 (int encoded_op, u64 __user *uaddr)
-{
- return 0;
+ return -ENOSYS;
}

#endif /* __KERNEL__ */
Index: linux-2.6.21-rc6-mm2/include/asm-sparc64/futex.h
===================================================================
--- linux-2.6.21-rc6-mm2.orig/include/asm-sparc64/futex.h 2007-04-20 14:01:25.000000000 +0200
+++ linux-2.6.21-rc6-mm2/include/asm-sparc64/futex.h 2007-04-20 13:48:48.000000000 +0200
@@ -108,13 +108,7 @@ futex_atomic_cmpxchg_inatomic(int __user
static inline u64
futex_atomic_cmpxchg_inatomic64(u64 __user *uaddr, u64 oldval, u64 newval)
{
- return 0;
-}
-
-static inline int
-futex_atomic_op_inuser64 (int encoded_op, u64 __user *uaddr)
-{
- return 0;
+ return -ENOSYS;
}

#endif /* !(_SPARC64_FUTEX_H) */
Index: linux-2.6.21-rc6-mm2/include/asm-um/futex.h
===================================================================
--- linux-2.6.21-rc6-mm2.orig/include/asm-um/futex.h 2007-04-20 14:01:25.000000000 +0200
+++ linux-2.6.21-rc6-mm2/include/asm-um/futex.h 2007-04-20 13:51:42.000000000 +0200
@@ -6,14 +6,7 @@
static inline u64
futex_atomic_cmpxchg_inatomic64(u64 __user *uaddr, u64 oldval, u64 newval)
{
- return 0;
+ return -ENOSYS;
}

-static inline int
-futex_atomic_op_inuser64 (int encoded_op, u64 __user *uaddr)
-{
- return 0;
-}
-
-
#endif
Index: linux-2.6.21-rc6-mm2/include/asm-x86_64/futex.h
===================================================================
--- linux-2.6.21-rc6-mm2.orig/include/asm-x86_64/futex.h 2007-04-20 14:01:25.000000000 +0200
+++ linux-2.6.21-rc6-mm2/include/asm-x86_64/futex.h 2007-04-20 13:50:38.000000000 +0200
@@ -41,38 +41,6 @@
"=&r" (tem) \
: "r" (oparg), "i" (-EFAULT), "m" (*uaddr), "1" (0))

-#define __futex_atomic_op1_64(insn, ret, oldval, uaddr, oparg) \
- __asm__ __volatile ( \
-"1: " insn "\n" \
-"2: .section .fixup,\"ax\"\n\
-3: movq %3, %1\n\
- jmp 2b\n\
- .previous\n\
- .section __ex_table,\"a\"\n\
- .align 8\n\
- .quad 1b,3b\n\
- .previous" \
- : "=r" (oldval), "=r" (ret), "=m" (*uaddr) \
- : "i" (-EFAULT), "m" (*uaddr), "0" (oparg), "1" (0))
-
-#define __futex_atomic_op2_64(insn, ret, oldval, uaddr, oparg) \
- __asm__ __volatile ( \
-"1: movq %2, %0\n\
- movq %0, %3\n" \
- insn "\n" \
-"2: " LOCK_PREFIX "cmpxchgq %3, %2\n\
- jnz 1b\n\
-3: .section .fixup,\"ax\"\n\
-4: movq %5, %1\n\
- jmp 3b\n\
- .previous\n\
- .section __ex_table,\"a\"\n\
- .align 8\n\
- .quad 1b,4b,2b,4b\n\
- .previous" \
- : "=&a" (oldval), "=&r" (ret), "=m" (*uaddr), \
- "=&r" (tem) \
- : "r" (oparg), "i" (-EFAULT), "m" (*uaddr), "1" (0))

static inline int
futex_atomic_op_inuser (int encoded_op, int __user *uaddr)
@@ -128,60 +96,6 @@ futex_atomic_op_inuser (int encoded_op,
}

static inline int
-futex_atomic_op_inuser64 (int encoded_op, u64 __user *uaddr)
-{
- int op = (encoded_op >> 28) & 7;
- int cmp = (encoded_op >> 24) & 15;
- u64 oparg = (encoded_op << 8) >> 20;
- u64 cmparg = (encoded_op << 20) >> 20;
- u64 oldval = 0, ret, tem;
-
- if (encoded_op & (FUTEX_OP_OPARG_SHIFT << 28))
- oparg = 1 << oparg;
-
- if (! access_ok (VERIFY_WRITE, uaddr, sizeof(u64)))
- return -EFAULT;
-
- inc_preempt_count();
-
- switch (op) {
- case FUTEX_OP_SET:
- __futex_atomic_op1_64("xchgq %0, %2", ret, oldval, uaddr, oparg);
- break;
- case FUTEX_OP_ADD:
- __futex_atomic_op1_64(LOCK_PREFIX "xaddq %0, %2", ret, oldval,
- uaddr, oparg);
- break;
- case FUTEX_OP_OR:
- __futex_atomic_op2_64("orq %4, %3", ret, oldval, uaddr, oparg);
- break;
- case FUTEX_OP_ANDN:
- __futex_atomic_op2_64("andq %4, %3", ret, oldval, uaddr, ~oparg);
- break;
- case FUTEX_OP_XOR:
- __futex_atomic_op2_64("xorq %4, %3", ret, oldval, uaddr, oparg);
- break;
- default:
- ret = -ENOSYS;
- }
-
- dec_preempt_count();
-
- 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;
- }
- }
- return ret;
-}
-
-static inline int
futex_atomic_cmpxchg_inatomic(int __user *uaddr, int oldval, int newval)
{
if (!access_ok(VERIFY_WRITE, uaddr, sizeof(int)))
Index: linux-2.6.21-rc6-mm2/include/asm-x86_64/unistd.h
===================================================================
--- linux-2.6.21-rc6-mm2.orig/include/asm-x86_64/unistd.h 2007-04-20 14:01:25.000000000 +0200
+++ linux-2.6.21-rc6-mm2/include/asm-x86_64/unistd.h 2007-04-20 13:50:42.000000000 +0200
@@ -619,8 +619,6 @@ __SYSCALL(__NR_sync_file_range, sys_sync
__SYSCALL(__NR_vmsplice, sys_vmsplice)
#define __NR_move_pages 279
__SYSCALL(__NR_move_pages, sys_move_pages)
-#define __NR_futex64 280
-__SYSCALL(__NR_futex64, sys_futex64)
#define __NR_signalfd 281
__SYSCALL(__NR_signalfd, sys_signalfd)
#define __NR_timerfd 282
Index: linux-2.6.21-rc6-mm2/include/linux/futex.h
===================================================================
--- linux-2.6.21-rc6-mm2.orig/include/linux/futex.h 2007-04-20 14:01:24.000000000 +0200
+++ linux-2.6.21-rc6-mm2/include/linux/futex.h 2007-04-20 13:47:36.000000000 +0200
@@ -19,6 +19,12 @@ union ktime;
#define FUTEX_TRYLOCK_PI 8
#define FUTEX_CMP_REQUEUE_PI 9

+#ifdef CONFIG_64BIT
+#define FUTEX_64BIT 0x80000000
+#define FUTEX_WAIT64 FUTEX_WAIT|FUTEX_64BIT
+#define FUTEX_CMP_REQUEUE64 FUTEX_CMP_REQUEUE|FUTEX_64BIT
+#endif
+
/*
* Support for robust futexes: the kernel cleans up held futexes at
* thread exit time.
@@ -104,7 +110,7 @@ struct robust_list_head {
#ifdef __KERNEL__
long do_futex(unsigned long __user *uaddr, int op, unsigned long val,
union ktime *timeout, unsigned long __user *uaddr2,
- unsigned long val2, unsigned long val3, int futex64);
+ unsigned long val2, unsigned long val3);

extern int
handle_futex_death(u32 __user *uaddr, struct task_struct *curr, int pi);
Index: linux-2.6.21-rc6-mm2/include/linux/syscalls.h
===================================================================
--- linux-2.6.21-rc6-mm2.orig/include/linux/syscalls.h 2007-04-20 14:01:25.000000000 +0200
+++ linux-2.6.21-rc6-mm2/include/linux/syscalls.h 2007-04-20 13:48:12.000000000 +0200
@@ -178,9 +178,6 @@ asmlinkage long sys_set_tid_address(int
asmlinkage long sys_futex(u32 __user *uaddr, int op, u32 val,
struct timespec __user *utime, u32 __user *uaddr2,
u32 val3);
-asmlinkage long sys_futex64(u64 __user *uaddr, int op, u64 val,
- struct timespec __user *utime, u64 __user *uaddr2,
- u64 val3);

asmlinkage long sys_init_module(void __user *umod, unsigned long len,
const char __user *uargs);
Index: linux-2.6.21-rc6-mm2/kernel/futex.c
===================================================================
--- linux-2.6.21-rc6-mm2.orig/kernel/futex.c 2007-04-20 14:01:24.000000000 +0200
+++ linux-2.6.21-rc6-mm2/kernel/futex.c 2007-04-20 15:31:23.000000000 +0200
@@ -62,20 +62,6 @@
#define FUTEX_HASHBITS (CONFIG_BASE_SMALL ? 4 : 8)

#ifdef CONFIG_64BIT
-static inline unsigned long
-futex_cmpxchg_inatomic(unsigned long __user *uaddr, unsigned long oldval,
- unsigned long newval, int futex64)
-{
- if (futex64)
- return futex_atomic_cmpxchg_inatomic64((u64 __user *)uaddr,
- oldval, newval);
- else {
- u32 ov = oldval, nv = newval;
- return futex_atomic_cmpxchg_inatomic((int __user *)uaddr, ov,
- nv);
- }
-}
-
static inline int
futex_get_user(unsigned long *val, unsigned long __user *uaddr, int futex64)
{
@@ -92,11 +78,7 @@ futex_get_user(unsigned long *val, unsig
}

#else
-#define futex_cmpxchg_inatomic(uaddr, oldval, newval, futex64) \
- futex_atomic_cmpxchg_inatomic((u32*)uaddr, oldval, newval)
-
#define futex_get_user(val, uaddr, futex64) get_user(*val, uaddr)
-
#endif

/*
@@ -606,12 +588,12 @@ static void wake_futex(struct futex_q *q
q->lock_ptr = NULL;
}

-static int wake_futex_pi(unsigned long __user *uaddr, unsigned long uval,
- struct futex_q *this, int futex64)
+static int wake_futex_pi(u32 __user *uaddr, unsigned long uval,
+ struct futex_q *this)
{
struct task_struct *new_owner;
struct futex_pi_state *pi_state = this->pi_state;
- unsigned long curval, newval;
+ u32 curval, newval;

if (!pi_state)
return -EINVAL;
@@ -639,7 +621,7 @@ static int wake_futex_pi(unsigned long _
newval |= (uval & FUTEX_WAITER_REQUEUED);

pagefault_disable();
- curval = futex_cmpxchg_inatomic(uaddr, uval, newval, futex64);
+ curval = futex_atomic_cmpxchg_inatomic(uaddr, uval, newval);
pagefault_enable();
if (curval == -EFAULT)
return -EFAULT;
@@ -664,17 +646,16 @@ static int wake_futex_pi(unsigned long _
return 0;
}

-static int unlock_futex_pi(unsigned long __user *uaddr, unsigned long uval,
- int futex64)
+static int unlock_futex_pi(u32 __user *uaddr, unsigned long uval)
{
- unsigned long oldval;
+ u32 oldval;

/*
* There is no waiter, so we unlock the futex. The owner died
* bit has not to be preserved here. We are the owner:
*/
pagefault_disable();
- oldval = futex_cmpxchg_inatomic(uaddr, uval, 0, futex64);
+ oldval = futex_atomic_cmpxchg_inatomic(uaddr, uval, 0);
pagefault_enable();

if (oldval == -EFAULT)
@@ -748,19 +729,20 @@ out:
* or create a new one without owner.
*/
static inline int
-lookup_pi_state_for_requeue(unsigned long __user *uaddr,
+lookup_pi_state_for_requeue(u32 __user *uaddr,
struct futex_hash_bucket *hb,
union futex_key *key,
- struct futex_pi_state **pi_state, int futex64)
+ struct futex_pi_state **pi_state)
{
- unsigned long curval, uval, newval;
+ u32 curval, uval, newval;

retry:
/*
* We can't handle a fault cleanly because we can't
* release the locks here. Simply return the fault.
*/
- if (get_futex_value_locked(&curval, uaddr, futex64))
+ if (get_futex_value_locked((unsigned long *)&curval,
+ (unsigned long __user *)uaddr, 0))
return -EFAULT;

/* set the flags FUTEX_WAITERS and FUTEX_WAITER_REQUEUED */
@@ -774,7 +756,7 @@ retry:
newval = uval | FUTEX_WAITERS | FUTEX_WAITER_REQUEUED;

pagefault_disable();
- curval = futex_cmpxchg_inatomic(uaddr, uval, newval, futex64);
+ curval = futex_atomic_cmpxchg_inatomic(uaddr, uval, newval);
pagefault_enable();

if (unlikely(curval == -EFAULT))
@@ -806,8 +788,8 @@ retry:
* one physical page to another physical page (PI-futex uaddr2)
*/
static int
-futex_requeue_pi(unsigned long __user *uaddr1, unsigned long __user *uaddr2,
- int nr_wake, int nr_requeue, unsigned long *cmpval, int futex64)
+futex_requeue_pi(u32 __user *uaddr1, u32 __user *uaddr2,
+ int nr_wake, int nr_requeue, unsigned long *cmpval)
{
union futex_key key1, key2;
struct futex_hash_bucket *hb1, *hb2;
@@ -840,9 +822,10 @@ retry:
double_lock_hb(hb1, hb2);

if (likely(cmpval != NULL)) {
- unsigned long curval;
+ u32 curval;

- ret = get_futex_value_locked(&curval, uaddr1, futex64);
+ ret = get_futex_value_locked((unsigned long*)&curval,
+ (unsigned long __user *)uaddr1, 0);

if (unlikely(ret)) {
spin_unlock(&hb1->lock);
@@ -855,7 +838,7 @@ retry:
*/
up_read(&current->mm->mmap_sem);

- ret = futex_get_user(&curval, uaddr1, futex64);
+ ret = get_user(curval, uaddr1);

if (!ret)
goto retry;
@@ -882,8 +865,7 @@ retry:
int s;
/* do this only the first time we requeue someone */
s = lookup_pi_state_for_requeue(uaddr2, hb2,
- &key2, &pi_state2,
- futex64);
+ &key2, &pi_state2);
if (s) {
ret = s;
goto out_unlock;
@@ -998,7 +980,7 @@ out:
*/
static int
futex_wake_op(unsigned long __user *uaddr1, unsigned long __user *uaddr2,
- int nr_wake, int nr_wake2, int op, int futex64)
+ int nr_wake, int nr_wake2, int op)
{
union futex_key key1, key2;
struct futex_hash_bucket *hb1, *hb2;
@@ -1022,16 +1004,10 @@ retryfull:
retry:
double_lock_hb(hb1, hb2);

-#ifdef CONFIG_64BIT
- if (futex64)
- op_ret = futex_atomic_op_inuser64(op, (u64 __user *)uaddr2);
- else
- op_ret = futex_atomic_op_inuser(op, (int __user *)uaddr2);
-#else
op_ret = futex_atomic_op_inuser(op, (int __user *)uaddr2);
-#endif
+
if (unlikely(op_ret < 0)) {
- unsigned long dummy;
+ u32 dummy;

spin_unlock(&hb1->lock);
if (hb1 != hb2)
@@ -1073,7 +1049,7 @@ retry:
*/
up_read(&current->mm->mmap_sem);

- ret = futex_get_user(&dummy, uaddr2, futex64);
+ ret = get_user(dummy, uaddr2);
if (ret)
return ret;

@@ -1379,8 +1355,18 @@ static int fixup_pi_state_owner(unsigned
while (!ret) {
newval = (uval & FUTEX_OWNER_DIED) | newtid;
newval |= (uval & FUTEX_WAITER_REQUEUED);
- curval = futex_cmpxchg_inatomic(uaddr,uval,
- newval, futex64);
+#ifdef CONFIG_64BIT
+ if (futex64)
+ curval = futex_atomic_cmpxchg_inatomic64(
+ (u64 __user *)uaddr,
+ uval, newval);
+ else
+#endif
+ curval = futex_atomic_cmpxchg_inatomic(
+ (u32 __user *)uaddr,
+ (u32)uval,
+ (u32)newval);
+
if (curval == -EFAULT)
ret = -EFAULT;
if (curval == uval)
@@ -1673,13 +1659,13 @@ static void set_pi_futex_owner(struct fu
* if there are waiters then it will block, it does PI, etc. (Due to
* races the kernel might see a 0 value of the futex too.)
*/
-static int futex_lock_pi(unsigned long __user *uaddr, int detect, ktime_t *time,
- int trylock, int futex64)
+static int futex_lock_pi(u32 __user *uaddr, int detect, ktime_t *time,
+ int trylock)
{
struct hrtimer_sleeper timeout, *to = NULL;
struct task_struct *curr = current;
struct futex_hash_bucket *hb;
- unsigned long uval, newval, curval;
+ u32 uval, newval, curval;
struct futex_q q;
int ret, lock_held, attempt = 0;

@@ -1714,7 +1700,7 @@ static int futex_lock_pi(unsigned long _
newval = current->pid;

pagefault_disable();
- curval = futex_cmpxchg_inatomic(uaddr, 0, newval, futex64);
+ curval = futex_atomic_cmpxchg_inatomic(uaddr, 0, newval);
pagefault_enable();

if (unlikely(curval == -EFAULT))
@@ -1759,7 +1745,7 @@ static int futex_lock_pi(unsigned long _
newval = curval | FUTEX_WAITERS;

pagefault_disable();
- curval = futex_cmpxchg_inatomic(uaddr, uval, newval, futex64);
+ curval = futex_atomic_cmpxchg_inatomic(uaddr, uval, newval);
pagefault_enable();

if (unlikely(curval == -EFAULT))
@@ -1796,8 +1782,8 @@ static int futex_lock_pi(unsigned long _
FUTEX_OWNER_DIED | FUTEX_WAITERS;

pagefault_disable();
- curval = futex_cmpxchg_inatomic(uaddr, uval,
- newval, futex64);
+ curval = futex_atomic_cmpxchg_inatomic(uaddr, uval,
+ newval);
pagefault_enable();

if (unlikely(curval == -EFAULT))
@@ -1841,7 +1827,8 @@ static int futex_lock_pi(unsigned long _
*/
if (!ret && q.pi_state->owner != curr)
/* mmap_sem is unlocked at return of this function */
- ret = fixup_pi_state_owner(uaddr, &q, hb, curr, futex64);
+ ret = fixup_pi_state_owner((unsigned long __user *)uaddr,
+ &q, hb, curr, 0);
else {
/*
* Catch the rare case, where the lock was released
@@ -1887,7 +1874,7 @@ static int futex_lock_pi(unsigned long _
queue_unlock(&q, hb);
up_read(&curr->mm->mmap_sem);

- ret = futex_get_user(&uval, uaddr, futex64);
+ ret = get_user(uval, uaddr);
if (!ret && (uval != -EFAULT))
goto retry;

@@ -1899,17 +1886,17 @@ static int futex_lock_pi(unsigned long _
* This is the in-kernel slowpath: we look up the PI state (if any),
* and do the rt-mutex unlock.
*/
-static int futex_unlock_pi(unsigned long __user *uaddr, int futex64)
+static int futex_unlock_pi(u32 __user *uaddr)
{
struct futex_hash_bucket *hb;
struct futex_q *this, *next;
- unsigned long uval;
+ u32 uval;
struct plist_head *head;
union futex_key key;
int ret, attempt = 0;

retry:
- if (futex_get_user(&uval, uaddr, futex64))
+ if (get_user(uval, uaddr))
return -EFAULT;
/*
* We release only a lock we actually own:
@@ -1936,7 +1923,7 @@ retry_locked:
*/
if (!(uval & FUTEX_OWNER_DIED)) {
pagefault_disable();
- uval = futex_cmpxchg_inatomic(uaddr, current->pid, 0, futex64);
+ uval = futex_atomic_cmpxchg_inatomic(uaddr, current->pid, 0);
pagefault_enable();
}

@@ -1958,7 +1945,7 @@ retry_locked:
plist_for_each_entry_safe(this, next, head, list) {
if (!match_futex (&this->key, &key))
continue;
- ret = wake_futex_pi(uaddr, uval, this, futex64);
+ ret = wake_futex_pi(uaddr, uval, this);
/*
* The atomic access to the futex value
* generated a pagefault, so retry the
@@ -1972,7 +1959,7 @@ retry_locked:
* No waiters - kernel unlocks the futex:
*/
if (!(uval & FUTEX_OWNER_DIED)) {
- ret = unlock_futex_pi(uaddr, uval, futex64);
+ ret = unlock_futex_pi(uaddr, uval);
if (ret == -EFAULT)
goto pi_faulted;
}
@@ -2002,7 +1989,7 @@ pi_faulted:
spin_unlock(&hb->lock);
up_read(&current->mm->mmap_sem);

- ret = futex_get_user(&uval, uaddr, futex64);
+ ret = get_user(uval, uaddr);
if (!ret && (uval != -EFAULT))
goto retry;

@@ -2323,92 +2310,70 @@ void exit_robust_list(struct task_struct

long do_futex(unsigned long __user *uaddr, int op, unsigned long val,
ktime_t *timeout, unsigned long __user *uaddr2,
- unsigned long val2, unsigned long val3, int fut64)
+ unsigned long val2, unsigned long val3)
{
int ret;

switch (op) {
case FUTEX_WAIT:
- ret = futex_wait(uaddr, val, timeout, fut64);
+ ret = futex_wait(uaddr, val, timeout, 0);
break;
case FUTEX_WAKE:
ret = futex_wake(uaddr, val);
break;
case FUTEX_FD:
- if (fut64)
- ret = -ENOSYS;
- else
- /* non-zero val means F_SETOWN(getpid())&F_SETSIG(val) */
- ret = futex_fd((u32 __user *)uaddr, val);
+ /* non-zero val means F_SETOWN(getpid())&F_SETSIG(val) */
+ ret = futex_fd((u32 __user *)uaddr, val);
break;
case FUTEX_REQUEUE:
- ret = futex_requeue(uaddr, uaddr2, val, val2, NULL, fut64);
+ ret = futex_requeue(uaddr, uaddr2, val, val2, NULL, 0);
break;
case FUTEX_CMP_REQUEUE:
- ret = futex_requeue(uaddr, uaddr2, val, val2, &val3, fut64);
+ ret = futex_requeue(uaddr, uaddr2, val, val2, &val3, 0);
break;
case FUTEX_WAKE_OP:
- ret = futex_wake_op(uaddr, uaddr2, val, val2, val3, fut64);
+ ret = futex_wake_op(uaddr, uaddr2, val, val2, val3);
break;
case FUTEX_LOCK_PI:
- ret = futex_lock_pi(uaddr, val, timeout, 0, fut64);
+ ret = futex_lock_pi((u32 __user *)uaddr, val, timeout, 0);
break;
case FUTEX_UNLOCK_PI:
- ret = futex_unlock_pi(uaddr, fut64);
+ ret = futex_unlock_pi((u32 __user *)uaddr);
break;
case FUTEX_TRYLOCK_PI:
- ret = futex_lock_pi(uaddr, 0, timeout, 1, fut64);
+ ret = futex_lock_pi((u32 __user *)uaddr, 0, timeout, 1);
break;
case FUTEX_CMP_REQUEUE_PI:
- ret = futex_requeue_pi(uaddr, uaddr2, val, val2, &val3, fut64);
+ ret = futex_requeue_pi((u32 __user *)uaddr,
+ (u32 __user *)uaddr2,
+ val, val2, &val3);
+ break;
+#ifdef CONFIG_64BIT
+ case FUTEX_WAIT64:
+ ret = futex_wait(uaddr, val, timeout, 1);
+ break;
+ case FUTEX_CMP_REQUEUE64:
+ ret = futex_requeue(uaddr, uaddr2, val, val2, &val3, 1);
break;
+#endif
default:
ret = -ENOSYS;
}
return ret;
}

-#ifdef CONFIG_64BIT
-
-asmlinkage long
-sys_futex64(u64 __user *uaddr, int op, u64 val,
- struct timespec __user *utime, u64 __user *uaddr2, u64 val3)
-{
- struct timespec ts;
- ktime_t t, *tp = NULL;
- u64 val2 = 0;
-
- if (utime && (op == FUTEX_WAIT || op == FUTEX_LOCK_PI)) {
- if (copy_from_user(&ts, utime, sizeof(ts)) != 0)
- return -EFAULT;
- if (!timespec_valid(&ts))
- return -EINVAL;
-
- t = timespec_to_ktime(ts);
- if (op == FUTEX_WAIT)
- t = ktime_add(ktime_get(), t);
- tp = &t;
- }
- /*
- * requeue parameter in 'utime' if op == FUTEX_REQUEUE.
- */
- if (op == FUTEX_REQUEUE || op == FUTEX_CMP_REQUEUE
- || op == FUTEX_CMP_REQUEUE_PI)
- val2 = (unsigned long) utime;
-
- return do_futex((unsigned long __user*)uaddr, op, val, tp,
- (unsigned long __user*)uaddr2, val2, val3, 1);
-}
-
-#endif
-
asmlinkage long sys_futex(u32 __user *uaddr, int op, u32 val,
struct timespec __user *utime, u32 __user *uaddr2,
u32 val3)
{
struct timespec ts;
ktime_t t, *tp = NULL;
- u32 val2 = 0;
+ unsigned long val2 = 0;
+ int op2 = op;
+
+#ifdef CONFIG_64BIT
+ op &= ~FUTEX_64BIT;
+#endif

if (utime && (op == FUTEX_WAIT || op == FUTEX_LOCK_PI)) {
if (copy_from_user(&ts, utime, sizeof(ts)) != 0)
@@ -2426,10 +2391,10 @@ asmlinkage long sys_futex(u32 __user *ua
*/
if (op == FUTEX_REQUEUE || op == FUTEX_CMP_REQUEUE
|| op == FUTEX_CMP_REQUEUE_PI)
- val2 = (u32) (unsigned long) utime;
+ val2 = (unsigned long) utime;

- return do_futex((unsigned long __user*)uaddr, op, val, tp,
- (unsigned long __user*)uaddr2, val2, val3, 0);
+ return do_futex((unsigned long __user*)uaddr, op2, val, tp,
+ (unsigned long __user*)uaddr2, val2, val3);
}

static int futexfs_get_sb(struct file_system_type *fs_type,
Index: linux-2.6.21-rc6-mm2/kernel/futex_compat.c
===================================================================
--- linux-2.6.21-rc6-mm2.orig/kernel/futex_compat.c 2007-04-20 14:01:24.000000000 +0200
+++ linux-2.6.21-rc6-mm2/kernel/futex_compat.c 2007-04-20 13:41:57.000000000 +0200
@@ -161,5 +161,5 @@ asmlinkage long compat_sys_futex(u32 __u
val2 = (int) (unsigned long) utime;

return do_futex((unsigned long __user*)uaddr, op, val, tp,
- (unsigned long __user*)uaddr2, val2, val3, 0);
+ (unsigned long __user*)uaddr2, val2, val3);
}
Index: linux-2.6.21-rc6-mm2/kernel/sys_ni.c
===================================================================
--- linux-2.6.21-rc6-mm2.orig/kernel/sys_ni.c 2007-04-20 14:01:24.000000000 +0200
+++ linux-2.6.21-rc6-mm2/kernel/sys_ni.c 2007-04-20 13:41:54.000000000 +0200
@@ -41,7 +41,6 @@ cond_syscall(sys_sendmsg);
cond_syscall(sys_recvmsg);
cond_syscall(sys_socketcall);
cond_syscall(sys_futex);
-cond_syscall(sys_futex64);
cond_syscall(compat_sys_futex);
cond_syscall(sys_set_robust_list);
cond_syscall(compat_sys_set_robust_list);