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SubjectRe: Process VM Addr to Kernel VM Addr at Interrupt Time.
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alan@lxorguk.ukuu.org.uk (Alan Cox) writes:

> > peripheral card. The application give the peripheral device an address
> > within the applications address space. Some time later, the peripheral
>
> Thats the first mistake
>
> > back the address given to the peripheral device earlier. The ISR
> > now needs to access the data at the memory location read back, but
>
> It can't
>
> > knows the process ID of the applicaiton in question, but since it
> > is not executing with the context of that application, how can it
> > convert the address in the applications address space, to its
> > own virtual address space?
>
> The page might even be on disk.

Can you explain why the original proposal would not work if he:

mlock() on application buffer
mapped the memory into kernel space

From mlock() man page this seems like it would be safe...

--tony

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