reduce 'unknown op 265' message storm

[Alexander Best]

hi there,

i see a lot of these warnings:

'linux_sys_futex: unknown op 265'

although there is no support in the linuxulator for opcode 256
(FUTEX_CLOCK_REALTIME) it is possible to handle some of these cases earlier.

FUTEX_CLOCK_REALTIME can be used to tell linux to use CLOCK_REALTIME instead of
CLOCK_MONOTONIC. FUTEX_CLOCK_REALTIME however must only be set, if either
FUTEX_WAIT_BITSET or FUTEX_WAIT_REQUEUE_PI are set too. if that's not the case
we can die with -ENOSYS right at the beginning.

cheers.
alex

-- 
a13x
-------------- next part --------------
diff --git a/sys/compat/linux/linux_futex.c b/sys/compat/linux/linux_futex.c
index 01af020..00c657c 100644
--- a/sys/compat/linux/linux_futex.c
+++ b/sys/compat/linux/linux_futex.c
@@ -416,7 +416,7 @@ futex_atomic_op(struct thread *td, int encoded_op, uint32_t *uaddr)
 int
 linux_sys_futex(struct thread *td, struct linux_sys_futex_args *args)
 {
-	int op_ret, val, ret, nrwake;
+	int clockrt, nrwake, op_ret, ret, val;
 	struct linux_emuldata *em;
 	struct waiting_proc *wp;
 	struct futex *f, *f2 = NULL;
@@ -429,7 +429,18 @@ linux_sys_futex(struct thread *td, struct linux_sys_futex_args *args)
 	 * in most cases (ie. when futexes are not shared on file descriptor
 	 * or between different processes.).
 	 */
-	args->op = (args->op & ~LINUX_FUTEX_PRIVATE_FLAG);
+	args->op = args->op & ~LINUX_FUTEX_PRIVATE_FLAG;
+
+	/*
+	 * Currently support for switching between CLOCK_MONOTONIC and
+	 * CLOCK_REALTIME is not present. However Linux forbids the use of
+	 * FUTEX_CLOCK_REALTIME with any op except FUTEX_WAIT_BITSET and
+	 * FUTEX_WAIT_REQUEUE_PI.
+	 */
+	clockrt = args->op & LINUX_FUTEX_CLOCK_REALTIME;
+	args->op = args->op & ~LINUX_FUTEX_CLOCK_REALTIME;
+	if (clockrt && args->op != LINUX_FUTEX_WAIT_BITSET && args->op != LINUX_FUTEX_WAIT_REQUEUE_PI)
+		return (-ENOSYS);
 
 	switch (args->op) {
 	case LINUX_FUTEX_WAIT:
@@ -639,6 +650,14 @@ linux_sys_futex(struct thread *td, struct linux_sys_futex_args *args)
 		}
 		return (EINVAL);
 
+	case LINUX_FUTEX_WAIT_BITSET:
+		/* not yet implemented */
+		return (ENOSYS);
+
+	case LINUX_FUTEX_WAIT_REQUEUE_PI:
+		/* not yet implemented */
+		return (ENOSYS);
+
 	default:
 		printf("linux_sys_futex: unknown op %d\n", args->op);
 		return (ENOSYS);
diff --git a/sys/compat/linux/linux_futex.h b/sys/compat/linux/linux_futex.h
index 1d462a7..3a10918 100644
--- a/sys/compat/linux/linux_futex.h
+++ b/sys/compat/linux/linux_futex.h
@@ -48,8 +48,12 @@ extern struct mtx futex_mtx;
 #define LINUX_FUTEX_LOCK_PI	6
 #define LINUX_FUTEX_UNLOCK_PI	7
 #define LINUX_FUTEX_TRYLOCK_PI	8
+#define LINUX_FUTEX_WAIT_BITSET	9
+#define \
+LINUX_FUTEX_WAIT_REQUEUE_PI	11
 
 #define LINUX_FUTEX_PRIVATE_FLAG	128
+#define LINUX_FUTEX_CLOCK_REALTIME	256
 
 #define FUTEX_OP_SET            0	/* *(int *)UADDR2 = OPARG; */
 #define FUTEX_OP_ADD            1	/* *(int *)UADDR2 += OPARG; */