Messages in this thread | | | Date | Wed, 07 Jan 2009 17:43:24 -0800 | From | Hiroshi Shimamoto <> | Subject | Re: [RFC -tip 0/4] x86: reduce fixup of uaccess |
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H. Peter Anvin wrote: > Hiroshi Shimamoto wrote: >> This is my second try to reduce fixup code size for exceptions of uaccess. >> >> This patch series reduces fixup code for exceptions of uaccess in signal. >> >> I gave up to make direct jump to end of function when an exception occurs. >> However, I thought fixup code could be reduced. The concept is that to add >> uaccess_err in thread_info and set it to -EFAULT on exception, finally check >> this value on the last of function. >> >> Is this good to reduce code size? >> > > Hello Hiroshi,
Hello Peter,
> > The patches look technically really nice. I have a couple of stylistic > comments, though, which I'd like yours and others' comments on.
Thanks for comments.
> > This introduces a new blocking construct, and it's not immediately > obvious in the source code. I think introducing a technically redundant
Yeah, I think it's not friendly about readability now.
> set of braces and dropping the parens from the try construct and the > redundant pointer might look better: > > get_user_try { > /* do stuff */ > } get_user_catch(err);
OK, I'll update like that.
> > This makes it, in my opinion, much clearer that it is a new bracing > construct, and it also eliminates the need to form a pointer to "err"
I'm not sure which is better plain "err" or pointer to "err".
> (even though the compiler doesn't actually do so, it looks like it does > to the programmer.) > > Also, I don't think we need double underscores for the wrapping > construct, since the get_user/__get_user (check/nocheck) etc. > distinction doesn't directly apply there.
OK. Will drop underscores.
I'll repost update patches.
Thanks, Hiroshi
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