Messages in this thread |  | | | From | Roland McGrath <> | | Subject | Re: [PATCH] x86 tls prevent_tail_call | | Date | Tue, 26 Feb 2008 23:38:21 -0800 (PST) |
> i'm wondering, have you seen this happen in practice? We use
> sys_set_thread_area() for every new task started up. I guess we havent
> seen problems in the field yet because this early during startup tasks
> do not normally receive signals? (or if they do they are fatal and no
> user signal context is used.)
Tomasz saw it. I don't know what compiler or exact options to it he used.
> btw., this whole thing of us having to notice such tail-optimization
> incidents is totally fragile and unreliable. Shouldnt there be a "dont
> tail-optimize me" attribute which we could stick into asmlinkage?
I agree. It's come up before. I'll talk to compiler folks about it again.
> Perhaps sparse could detect asmlinkage functions that do not do
> prevent_tail_call()s?
That sounds like a good idea to me.
Thanks,
Roland
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