Messages in this thread | | | Date | Wed, 26 Aug 1998 04:17:34 -0700 | From | "David S. Miller" <> | Subject | Re: copy_from_user() fix |
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Date: Wed, 26 Aug 1998 10:55:30 +0200 From: Martin Mares <mj@ucw.cz>
To be honest, I see more legitimate advantages in SIGSEGV than in EFAULT. The only advantage of EFAULT is easy checking by callers which is IMHO used rarely. On the other hand, if you use SIGSEGV, you can get the faulting address and you get all accesses to invalid addresses trapped, making such (potentially dangerous, especially in security sensitive apps) cases easy to spot.
Consider a userland pointer verification library that worked in about 10 lines of code by passing the pointer in question to a sys_write() call to /dev/null... but this wouldn't work actually these days due to how the kernel won't even verify the pointer in this case.
But I am sure other interesting examples could be conceived.
Later, David S. Miller davem@dm.cobaltmicro.com
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