Re: [PATCH 2/2] Perform check in iov_iter_fault_in_readable() by check_readable_bytes()

[Jamie Lokier]

Alan Cox wrote:
> > System calls don't trigger SIGSEGVs so they can't rely on that when
> > calling read().  I'm not sure how they handle that.
> 
> Usually by touching the pages before the syscall.

Makes sense.

> (You can't rely on -EFAULT either in POSIX, its optional that it
> bothers to tell you and for example on MMUless it may well not)

On MMUless you wouldn't use page protection as a GC technique :-)
Is EFAULT really optional on systems with page protection?

-- Jamie
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