From: Timur Tabi <timur@freescale.com>
To: linuxppc-dev@ozlabs.org
Subject: Confused about usercopy_64.c
Date: Mon, 10 Mar 2008 11:38:49 -0500 [thread overview]
Message-ID: <47D56419.6000704@freescale.com> (raw)
I'm confused about something in usercopy_64.c:
unsigned long copy_from_user(void *to, const void __user *from, unsigned long n)
{
if (likely(access_ok(VERIFY_READ, from, n)))
n = __copy_from_user(to, from, n);
else
memset(to, 0, n);
return n;
}
If access_ok() returns false, then that means that we cannot copy the data from
user-space. So why are we returning 'n'? Shouldn't we return zero, to let the
caller know that the function failed?
--
Timur Tabi
Linux kernel developer at Freescale
next reply other threads:[~2008-03-10 16:38 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2008-03-10 16:38 Timur Tabi [this message]
2008-03-10 16:50 ` Confused about usercopy_64.c Olof Johansson
2008-03-10 16:53 ` Andreas Schwab
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