[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] Re: [Xen-devel] [PATCH] ns16550: limit mapped MMIO size
On Thu, 2015-11-12 at 08:52 -0700, Jan Beulich wrote: > There's no point in mapping more than the memory we actually may need > to touch, and in fact the too large region could actually extend into > another device's one (which currently is benign on x86 since only a > single page gets mapped anyway, but which is a latent bug on ARM > whenever PCI support gets enabled there). > > Signed-off-by: Jan Beulich <jbeulich@xxxxxxxx> > > --- a/xen/drivers/char/ns16550.c > +++ b/xen/drivers/char/ns16550.c > @@ -931,6 +931,8 @@ pci_uart_config (struct ns16550 *uart, i > ÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂuart->io_base += bar_idx * > uart_param[p].uart_offset; > ÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂif ( uart_param[p].base_baud ) > ÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂuart->clock_hz = uart_param[p].base_baud * > 16; > +ÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂsize = max(8U << uart_param[p].reg_shift, > +ÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂuart_param[p].uart_offset); I assume 8 bytes (suitably shifted as above) corresponds to the "need to touch" set of registers, but I can't fathom the link to uart_offset, rather than uart_offset + those 8 bytes or something like that. Ian. _______________________________________________ Xen-devel mailing list Xen-devel@xxxxxxxxxxxxx http://lists.xen.org/xen-devel
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