On Wed, Jan 28, 2015 at 09:04:38AM +0100, Michael Kerrisk (man-pages) wrote:
Hi Michael,
[..]
> >> * the number of bytes copied from userspace is min(bufsz, memsz)
> >
> > Yes. bufsz can not be more than memsz. There is a check to validate
> > this in kernel.
> >
> > result = -EINVAL;
> > for (i = 0; i < nr_segments; i++) {
> > if (image->segment[i].bufsz > image->segment[i].memsz)
> > return result;
> > }
>
> Okay. So it's more precise to leave discussion of min(bufz, memsz)
> out of the man page just to say: bufsz bytes are transferred;
> if bufsz < memsz, then the excess bytes in the target region are
> filled with zeros. Right?
Sounds good.
[..]
> > Both mem and memsz need to be page aligned.
>
> And the error if not is EADDRNOTAVAIL, right?
Yes.
>
> >> And one further question. Other than the fact that they are used with
> >> different system calls, what is the difference between KEXEC_ON_CRASH
> >> and KEXEC_FILE_ON_CRASH?
> >
> > Right now I can't think of any other difference. They both tell respective
> > system call that this kernel needs to be loaded in reserved memory region
> > for crash kernel.
>
> Okay.
>
> I've made various adjustments to the page in the light of your comments
> above. Thanks!
Thank you for following it up and improving kexec man page.
Thanks
Vivek
