This is the mail archive of the
libc-alpha@sourceware.org
mailing list for the glibc project.
Re: [RFC v2 PATCH] futex: extend set_robust_list to allow 2 locking ABIs at the same time.
- From: Florian Weimer <fweimer at redhat dot com>
- To: Shawn Landden <shawn at git dot icu>
- Cc: Thomas Gleixner <tglx at linutronix dot de>, libc-alpha at sourceware dot org, linux-api at vger dot kernel dot org, linux-kernel at vger dot kernel dot org, Arnd Bergmann <arnd at arndb dot de>, Deepa Dinamani <deepa dot kernel at gmail dot com>, Oleg Nesterov <oleg at redhat dot com>, Andrew Morton <akpm at linux-foundation dot org>, Catalin Marinas <catalin dot marinas at arm dot com>, Keith Packard <keithp at keithp dot com>
- Date: Tue, 05 Nov 2019 10:48:39 +0100
- Subject: Re: [RFC v2 PATCH] futex: extend set_robust_list to allow 2 locking ABIs at the same time.
- References: <20191104002909.25783-1-shawn@git.icu>
* Shawn Landden:
> If this new ABI is used, then bit 1 of the *next pointer of the
> user-space robust_list indicates that the futex_offset2 value should
> be used in place of the existing futex_offset.
The futex interface currently has some races which can only be fixed by
API changes. I'm concerned that we sacrifice the last bit for some
rather obscure feature. What if we need that bit for fixing the
correctness issues?
Thanks,
Florian