On 01/22/2016 10:59 AM, Michael Ellerman wrote: > On Thu, 2016-01-21 at 21:45 +0530, Vasant Hegde wrote: > >> With commit 90a545e9 (restrict /dev/mem to idle io memory ranges) mapping >> rtas_rmo_buf from user space is failing. Hence we are not able to make >> RTAS syscall. >> >> This patch calls page_is_rtas_user_buf before calling iomem_is_exclusive >> in devmem_is_allowed(). This will allow user space to map rtas_rmo_buf >> and we are able to make RTAS syscall.
Michael, > > Thanks for the patch. > > I'll put it in my fixes branch for next week. Thanks! > > > Having said that, why the <expletive deleted> is librtas mapping /dev/mem in > the first place? Unless there is a very good reason, and probably even if > there > is, we should fix that to use a sane API. We use rtas system call. We use /dev/mem interface to map the RTAS memory region (allocated by kernel and information is passed to user space via procfs) so that we can read/write to RTAS memory. I do not have historical information. May be Nathan has more information on this. -Vasant _______________________________________________ Linuxppc-dev mailing list [email protected] https://lists.ozlabs.org/listinfo/linuxppc-dev
