Re: [PATCH v3 10/15] futex: Add sys_futex_requeue()
From: Ingo Molnar <mingo@kernel.org>
Date: 2023-09-22 09:35:16
Also in:
linux-arch, linux-mm, lkml
* peterz@infradead.org [off-list ref] wrote:
quoted hunk ↗ jump to hunk
--- linux-2.6.orig/kernel/futex/syscalls.c +++ linux-2.6/kernel/futex/syscalls.c@@ -396,6 +396,44 @@ SYSCALL_DEFINE6(futex_wait, return ret; } +/* + * 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; + int ret; + + if (flags) + return -EINVAL;
Small detail, but isn't -ENOSYS the canonical error code for functionality not yet implemented - which the unused 'flags' ABI is arguably? -EINVAL is for recognized but incorrect parameters, such as:
+ if (!waiters) + return -EINVAL;
Thanks, Ingo