On Tue, Jun 5, 2018 at 7:32 AM, Bruce Evans <b...@optusnet.com.au> wrote: > This is the driver getting the check wrong for all frame buffer sizes that > are not a multiple of PAGE_SIZE. The frame buffer size is not a multiple > of PAGE SIZE mainly for the interesting geometries 800x600x8 and > 1920x1080x8. I use this fix: > > Index: vesa.c > =================================================================== > --- vesa.c (revision 334595) > +++ vesa.c (working copy) > @@ -1642,7 +1642,7 @@ > (adp->va_info.vi_flags & V_INFO_LINEAR) != 0) { > /* va_window_size == va_buffer_size/vi_planes */ > /* XXX: is this correct? */ > - if (offset > adp->va_window_size - PAGE_SIZE) > + if (offset > trunc_page(adp->va_window_size)) > return (-1); > *paddr = adp->va_info.vi_buffer + offset; > #ifdef VM_MEMATTR_WRITE_COMBINING > > After fixing this, even 1920x1080x8 works.
I submitted a (different) patch [0] that we've been using in production since 2014 for that particular code multiple times, most recently in January of 2018 [1]. It's not a libvgl-specific issue and honestly deserves to be fixed already. With it, we've been able to use sc as a pretty much bulletproof X target, with the caveat that it's insanely slow at higher (native) resolutions. This particular issue is actually already tracked in kern/162373, the same patch was submitted there by Mikhail Kupchik way back in November of 2011. Since you seem to know what you're doing - is the comparison with `trunc_page(adp->va_window_size)` here the way to go or the alternative approach with `offset >= adp->va_info.vi_buffer_size` range checking instead? Mahmoud Al-Qudsi NeoSmart Technologies [0]: https://github.com/neosmart/freebsd/commit/b3af2d1ed4a63fe1a5d771ed3a052242250098d7 [1]: http://freebsd.1045724.x6.nabble.com/PATCH-validated-against-50k-i686-machines-for-vmparam-h-and-vesa-c-td6235962.html _______________________________________________ freebsd-bugs@freebsd.org mailing list https://lists.freebsd.org/mailman/listinfo/freebsd-bugs To unsubscribe, send any mail to "freebsd-bugs-unsubscr...@freebsd.org"