Messages in this thread | | | Date | Thu, 15 May 2008 20:47:06 +1000 | From | Paul Mackerras <> | Subject | Re: [PATCH] Fix for OProfile callgraph for Power 64 bit user apps |
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Carl Love writes:
> The following patch fixes the 64 bit user code backtrace > which currently may hang the system.
What exactly is wrong with it?
Having now taken a much closer look, I now don't think Nate Case's patch addresses this, since it only affects constant size arguments <= 8 to copy_{to,from}_user_inatomic.
However, I don't see why your patch fixes anything. It means we do two access_ok calls and two __copy_from_user_inatomic calls, for 8 bytes, at sp and at sp + 16, rather than doing one access_ok and __copy_from_user_inatomic for 24 bytes at sp. Why does that make any difference (apart from being slower)?
Paul.
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