Messages in this thread | | | Date | Sat, 24 Jan 1998 11:06:35 -0500 | From | Bill Hawes <> | Subject | Re: My last word on copy_to_user |
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Michael Elizabeth Chastain wrote:
> Here is a list of places in 2.1.80 that call copy_to_user and expect > it to return -EFAULT, or a negative number, on error. These callers > are wrong. > > I think most, or all, of these places will work correctly as long > as the addresses are supplied are valid. In that case copy_to_user > returns 0 and every caller accepts 0 as a sign of success.
Hi Michael,
Thanks, your list is very useful. I've fixed the kernel/signal.c cases and picked up a couple of other problems while reviewing the code.
Another point I'd like to mention again -- copy_xx_user can block, so it's not correct to call it with interrupts turned off, for example. So when making the changes to fix the return values, it's a good idea to check around for race conditions as well.
Regards, Bill
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