sh: fix futex FUTEX_OP_SET op on userspace addresses

Commit 00b73d8 ("sh: add working futex atomic ops on userspace addresses for smp") changed the futex_atomic_op_inuser function to use a loop. In case of the FUTEX_OP_SET op with a userspace address containing a value different of 0, this loop is an endless loop. Fix that by loading the value of oldval from the userspace before doing the cmpxchg op, also for the FUTEX_OP_SET case. Signed-off-by: Aurelien Jarno <[email protected]> Signed-off-by: Rich Felker <[email protected]>
yishaih · Apr 12, 2018 · 9b7e30a · 9b7e30a
1 parent 0adb328
commit 9b7e30a
Showing 1 changed file with 1 addition and 4 deletions.
diff --git a/arch/sh/include/asm/futex.h b/arch/sh/include/asm/futex.h
@@ -37,10 +37,7 @@ static inline int arch_futex_atomic_op_inuser(int op, u32 oparg, int *oval,
 	pagefault_disable();
 
 	do {
-		if (op == FUTEX_OP_SET)
-			ret = oldval = 0;
-		else
-			ret = get_user(oldval, uaddr);
+		ret = get_user(oldval, uaddr);
 
 		if (ret) break;