Re: [PATCH v1 09/14] futex: Add sys_futex_requeue()
From: Peter Zijlstra <peterz@infradead.org>
Date: 2023-07-31 17:39:13
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On Mon, Jul 31, 2023 at 07:19:17PM +0200, Thomas Gleixner wrote:
On Fri, Jul 21 2023 at 12:22, Peter Zijlstra wrote:quoted
+/* + * sys_futex_requeue - Requeue a waiter from one futex to another + * @waiters: array describing the source and destination futex + * @flags: unused + * @nr_wake: number of futexes to wake + * @nr_requeue: number of futexes to requeue + * + * Identical to the traditional FUTEX_CMP_REQUEUE op, except it is part of the + * futex2 family of calls. + */ + +SYSCALL_DEFINE4(futex_requeue, + struct futex_waitv __user *, waiters, + unsigned int, flags, + int, nr_wake, + int, nr_requeue) +{ + struct futex_vector futexes[2]; + u32 cmpval;So this is explictely u32. I'm completely confused vs. the 64 bit futex size variant enablement earlier in the series by now.
As per the previous email; these patches only enable the syscall part of 64bit futexes, they do not convert the core, and per futex_flags_valid() (patches 4 and 13), explicitly disallow having FUTEX2_64 set. - /* Only 32bit futexes are implemented -- for now */ - if ((flags & FLAGS_SIZE_MASK) != FLAGS_SIZE_32) + /* 64bit futexes aren't implemented -- yet */ + if ((flags & FLAGS_SIZE_MASK) == FLAGS_SIZE_64) return false;