From: Jason Gunthorpe <jgg@xxxxxxxxxxxx> Sent: Tuesday, May 15, 2018 5:22 PM > On Tue, May 15, 2018 at 11:06:21AM +0000, Kalderon, Michal wrote: > > > From: linux-rdma-owner@xxxxxxxxxxxxxxx [mailto:linux-rdma- > > > owner@xxxxxxxxxxxxxxx] On Behalf Of Jason Gunthorpe > > > On Mon, May 14, 2018 at 08:01:32PM +0000, Kalderon, Michal wrote: > > > > From: linux-rdma-owner@xxxxxxxxxxxxxxx > > > > <linux-rdma-owner@xxxxxxxxxxxxxxx> on behalf of Jason Gunthorpe > > > > <jgg@xxxxxxxxxxxx> > > > > > > > > > > > > 1 file changed, 28 insertions(+), 31 deletions(-) > > > > > > > > > > > > > > > > Please don't leak kernel pointers [1], and use %pK instead of %x [2]. > > > > > > > > > > > > > > [1] https://lwn.net/Articles/735589/ [2] > > > > > > > Documentation/core-api/printk-formats.rst > > > > > > > > > > > > > > Thanks > > > > > > > > > > Thanks for pointing these out. I was not familiar with this > > > > > > convention. However, the addresses Which are printed below are the > > > > > > physical doorbell addresses which don't > > > > > > > > > I think PCI physical addresses are expected to be protected as well. > > > > > > > > Not sure what can be done though with this physical address, as it is > > > > an address into the devices doorbell -> any attempt to write data that > > > > is not in the doorbell format will be dropped by device. > > > > > > It obscures information about the kernel memory layout which is the point of > > > all of this. > > > > > > If you want to report the doorbell address for debugging then report it as an > > > offset from the start of the device's bar. > > > > The doorbell bar address (all bars ) is visible with a simple lspci -vv ( also when run > > with non-priviledged user and kptr_restrict=2) Why is reporting it in printk > > a leak in this case? > > I didn't make feature.. > > But if I recall, lspci -vv only shows the bar physical address because > your system is not in a high enough security mode? > I'll check again, thanks. In any case, following discussion with Leon I saw that using pK does give the same information needed, sent a v2 with the fix. thanks, Michal > > Jason -- To unsubscribe from this list: send the line "unsubscribe linux-rdma" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
