On 8/27/19 5:07 PM, Bjorn Andersson wrote: > On Tue 27 Aug 13:25 PDT 2019, Suman Anna wrote: > >> Hi Bjorn, >> >> On 8/27/19 12:10 AM, Bjorn Andersson wrote: >>> On Fri 09 Aug 13:25 PDT 2019, Suman Anna wrote: >>> >>>> Hi Bjorn, >>>> >>> >>> Hi Suman >>> >>>> On 10/23/18 8:19 PM, Suman Anna wrote: >>>>> The virtio_rpmsg_bus driver uses the "%p" format-specifier for >>>>> printing the vring buffer address. This prints only a hashed >>>>> pointer even for previliged users. Use "%pK" instead so that >>>>> the address can be printed during debug using kptr_restrict >>>>> sysctl. >>>> >>>> Seems to have been lost among the patches, can you pick up this trivial >>>> patch for 5.4? Should apply cleanly on the latest HEAD as well. >>>> >>> >>> I share Andrew's question regarding what benefit you have from knowing >>> this value. Should we not just remove the va from the print? Or do you >>> actually have a use case for it?. >> >> I mainly use it during debug when comparing against kernel_page_tables >> and vmallocinfo. The pools that we use are not always guaranteed to be >> from linear memory, and behavior changes when using with CMA or DMA pools. >> > > Thanks Suman. It seems to me that there's room for improvement to aid > this kind of debugging. But your usecase seems reasonable, so I'm > merging the patch. Thanks Bjorn. > >> Note that usage of %pK does not leak the addresses automatically, but >> atleast enables me to get the values when needed. The changes also bring >> the usage in rpmsg core in sync with the remoteproc core. >> > > Sounds like shouldn't have merged them in remoteproc then ;P Slightly different reasoning looking at the commit, it was probably when %p was leaking the addresses. regards Suman > > Thanks, > Bjorn > >> regards >> Suman >> >>> >>> Regards, >>> Bjorn >>> >>>> regards >>>> Suman >>>> >>>>> >>>>> Signed-off-by: Suman Anna <s-anna@xxxxxx> >>>>> --- >>>>> drivers/rpmsg/virtio_rpmsg_bus.c | 2 +- >>>>> 1 file changed, 1 insertion(+), 1 deletion(-) >>>>> >>>>> diff --git a/drivers/rpmsg/virtio_rpmsg_bus.c b/drivers/rpmsg/virtio_rpmsg_bus.c >>>>> index f29dee731026..1345f373a1a0 100644 >>>>> --- a/drivers/rpmsg/virtio_rpmsg_bus.c >>>>> +++ b/drivers/rpmsg/virtio_rpmsg_bus.c >>>>> @@ -950,7 +950,7 @@ static int rpmsg_probe(struct virtio_device *vdev) >>>>> goto vqs_del; >>>>> } >>>>> >>>>> - dev_dbg(&vdev->dev, "buffers: va %p, dma %pad\n", >>>>> + dev_dbg(&vdev->dev, "buffers: va %pK, dma %pad\n", >>>>> bufs_va, &vrp->bufs_dma); >>>>> >>>>> /* half of the buffers is dedicated for RX */ >>>>> >>>> >>
