[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: [PATCH V5 00/22] IOREQ feature (+ virtio-mmio) on Arm

On 26.01.21 01:20, Julien Grall wrote:

Hi Julien, Stefano

On Mon, 25 Jan 2021 at 20:56, Stefano Stabellini <sstabellini@xxxxxxxxxx> wrote:

This seems to be an arm randconfig failure:

Thanks! The error is:

#'target_mem_ref' not supported by expression#'memory.c: In function
memory.c:1210:18: error:  may be used uninitialized in this function
  1210 |             rc = set_foreign_p2m_entry(currd, d, gfn_list[i],
       |                  ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  1211 |                                        _mfn(mfn_list[i]));
       |                                        ~~~~~~~~~~~~~~~~~~

I found a few references online of the error message, but it is not
clear what it means. From a quick look at Oleksandr's branch, I also
can't spot anything unitialized. Any ideas?
It seems that error happens if *both* CONFIG_GRANT_TABLE and CONFIG_IOREQ_SERVER are disabled. Looks like that mfn_list is initialized either in acquire_grant_table() or in acquire_ioreq_server(). If these options disabled then corresponding helpers are just stubs, so indeed that mfn_list gets uninitialized. But, I am not sure why gcc complains about it as set_foreign_p2m_entry() is *not* going to be called in that case???


Oleksandr Tyshchenko



Lists.xenproject.org is hosted with RackSpace, monitoring our
servers 24x7x365 and backed by RackSpace's Fanatical Support®.