Re: copy_from_user
From: Amol Kumar Lad <hidden>
Date: 2002-12-23 15:02:18
yeah..u are right... how stupid of me... I should have read whole function... I thought..aceess_ok should make such check... thanks Amol On Sun, 2002-12-22 at 20:21, Ravi wrote:
quoted hunk ↗ jump to hunk
--- Amol Kumar Lad <amolk@ishoni.com> wrote:quoted
Suppose kernel tries to do copy_from_user from a pointer that does not have any mapping. i.e. not in any VMA (and notinquoted
stack area too..). Now (for 1386) access_ok --> __range_ok Suppose the 'from' ptr is within range then how kernel is making sure that 'from' is invalid ?? The page fault handler will see that 'from' has no mapping and it will die..I believe this is handled using the 'fixup' code in __copy_user_zeroing(). I don't understand the code well though, but I do know that it works :) -Ravi. __________________________________________________ Do you Yahoo!? Yahoo! Mail Plus - Powerful. Affordable. Sign up now. http://mailplus.yahoo.com
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