Matthew Dillon <[EMAIL PROTECTED]> writes:
>:I was just playing with mmap() really for the first time, and I noticed
>:something a bit odd. When you mmap() a file for writing, it also appears
>:to require that you give it read permissions, else it dies on a signal 10.
>
>    I've got a few hundred terrabytes of WOM to sell ya!

        I'll sell you a few petabytes!

>    This is just a byproduct of the MMU implementation.  Most MMU's do
>    not support write-only maps because most do not implement separate
>    read and write bits.  You get a valid and a write-enable bit instead,
>    or you just get a valid bit and have to use the dirty bit to make the
>    page writable (no write-enable bit at all).

        Makes sense.

        Shouldn't the mmap() return MAP_FAILED, probably with EACCES,
instead of causing a signal 10?

-- 
Randell Jesup, Worldgate Communications, ex-Scala, ex-Amiga OS team ('88-94)
[EMAIL PROTECTED]



To Unsubscribe: send mail to [EMAIL PROTECTED]
with "unsubscribe freebsd-hackers" in the body of the message

Reply via email to