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From: David Woodhouse <dwmw2@infradead.org>
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To: Linus Torvalds <torvalds@transmeta.com>
Cc: Roman Zippel <zippel@linux-m68k.org>, David Howells <dhowells@redhat.com>,
       alan@redhat.com, linux-kernel@vger.kernel.org
Subject: Re: manipulating sigmask from filesystems and drivers 
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torvalds@transmeta.com said:
>  It's not the kernel side that is not restartable. It's the _user_
> side. 

As I said, you can't allow it to be interrupted after you've started the 
copy_to_user(). Show me how the userspace program can prove the signal 
arrived _after_ the 'int 0x80' had trapped into the kernel rather then 
beforehand, and I'll accept that you can't allow read() to be interrupted
even before the copy_to_user() starts.

But I also agree that there are other, better, examples of why
TASK_UNINTERRUPTIBLE has to be used sometimes. Page faults in 
copy_{from,to}_user are probably one such.

It's just that it doesn't have to be scattered all over the place just
because people are too lazy to do the cleanup code.

Yeah -- sometimes it's hard. So go shopping.

--
dwmw2


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