Re: [PATCH] [RFC] Optimize select/poll by putting small data setson the stack

[Eric Dumazet]

Arnd Bergmann a écrit :
> Interestingly, doing a diff between sys_select and compat_sys_select
> in the current kernel seems to suggest that they are both buggy
> in that they miss checks for failing __put_user, but in /different/
> places.

And I would like to pinpoint that set_fd_set() implementation seems *buggy* :

It should not use __copy_to_user() but the real one (copy_to_user()) because 
the calling thread could have slept in do_select() and another thread played 
mm games during this sleep.

Eric
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