Re: Linux 3.3-rc4

From: Eric Dumazet
Date: Tue Feb 21 2012 - 18:11:04 EST


Le mardi 21 fÃvrier 2012 Ã 14:43 -0800, Linus Torvalds a Ãcrit :
> On Sun, Feb 19, 2012 at 5:42 AM, Thomas Meyer <thomas@xxxxxxxx> wrote:
> >
> > 2.) while debugging above issue: I did find an minor bug in sys_poll() - nobody did take care of my proposed patch: https://lkml.org/lkml/2011/9/24/35
>
> Ok, so I started out forward-porting that patch to current -git
> (trivial: it's just that the system call tables are differently
> generated now), but the more I look at it, the more I suspect that we
> should perhaps just globally fix "sys_poll()" to have the timeout
> argument be 'int'.
>
> Because that *is* the standard user interface (just do "man 2 poll"),
> and while all of the git history (and all of the BK history) we've had
> it as "long", I suspect we should just fix it.
>
> So I suspect the correct patch is just as attached instead: make
> sys_poll() just take an "int timeout". Any user who tried to use a
> long value would already have got truncated by glibc - I just checked.
>
> Of course, there is a remote possibility that somebody might not use
> glibc, and have used "poll()" with the raw system call interface, and
> depended on using a 64-bit "long timeout" on 64-bit architectures.
>
> But quite frankly, that sounds rather unlikely in the extreme.
>
> Comments? If we do this, and somebody actually reports that they use a
> 64-bit timeout, we could always go back to the broken 'long' argument,
> and take your patch to fix the compat case.
>
> Linus

Yep, this is what I thought, but when this was raised last september,
both Andrew and Andi disagreed.

https://lkml.org/lkml/2011/10/6/389



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