Re: 4.14.0 FTBFS for Debian unstable, libxlu_pci.c (?°□°）?? ©擤ォß

[Michael Young <m.a.young@xxxxxxxxxxxx>]

On Fri, 31 Jul 2020, Hans van Kranenburg wrote:

> Hi!
>
> News from the Debian Xen team (well, that's still only Ian and me). We
> still have Xen 4.11 in Debian unstable and stable (Buster) now, but at
> this point I really want to start working on the preparations for the
> next Debian release which will happen in about a little bit less than a
> year from now.
>
> So, the 4.14.0 release is a good moment to kick it off. In february 2020
> Ian and I already spent a day to move the Debian packaging to 4.13, and
> the result has been laying around for a bit. Now I'm forwarding it to
> 4.14.0 and I really want to get this in Debian so users can start
> playing around with it and have enough time to either contribute new
> things (like cross-building for raspberry pi4!) etc.
>
> All the yolo WIP stuff without anything cleaned up is here:
> https://salsa.debian.org/xen-team/debian-xen/-/commits/knorrie/4.14
>
> Unfortunately, it FTBFS in an unexpected way, since I cannot relate this
> to any of our additional patches or anything.
>
> This is the last part of the output with the failure:
>
> ---- >8 ----
>
> gcc  -m64 -DBUILD_ID -fno-strict-aliasing -std=gnu99 -Wall
> -Wstrict-prototypes -Wdeclaration-after-statement
> -Wno-unused-but-set-variable -Wno-unused-local-typedefs   -O2
> -fomit-frame-pointer
> -D__XEN_INTERFACE_VERSION__=__XEN_LATEST_INTERFACE_VERSION__ -MMD -MP
> -MF .libxlu_pci.o.d -D_LARGEFILE_SOURCE -D_LARGEFILE64_SOURCE  -g -O2
> -fdebug-prefix-map=/home/knorrie/build/xen/debian-xen=.
> -fstack-protector-strong -Wformat -Werror=format-security -Wdate-time
> -D_FORTIFY_SOURCE=2 -Werror -Wno-format-zero-length
> -Wmissing-declarations -Wno-declaration-after-statement
> -Wformat-nonliteral -I. -fPIC -pthread
> -I/home/knorrie/build/xen/debian-xen/tools/libxl/../../tools/libxc/include
> -I/home/knorrie/build/xen/debian-xen/tools/libxl/../../tools/libs/toollog/include
> -I/home/knorrie/build/xen/debian-xen/tools/libxl/../../tools/include
> -I/home/knorrie/build/xen/debian-xen/tools/libxl/../../tools/libs/foreignmemory/include
> -I/home/knorrie/build/xen/debian-xen/tools/libxl/../../tools/include
> -I/home/knorrie/build/xen/debian-xen/tools/libxl/../../tools/libs/devicemodel/include
> -I/home/knorrie/build/xen/debian-xen/tools/libxl/../../tools/include
> -I/home/knorrie/build/xen/debian-xen/tools/libxl/../../tools/include
> -D__XEN_TOOLS__   -c -o libxlu_pci.o libxlu_pci.c
> libxlu_pci.c: In function 'xlu_pci_parse_bdf':
> libxlu_pci.c:32:18: error: 'func' may be used uninitialized in this
> function [-Werror=maybe-uninitialized]
>   32 |     pcidev->func = func;
>      |     ~~~~~~~~~~~~~^~~~~~
> libxlu_pci.c:51:29: note: 'func' was declared here
>   51 |     unsigned dom, bus, dev, func, vslot = 0;
>      |                             ^~~~
> libxlu_pci.c:31:17: error: 'dev' may be used uninitialized in this
> function [-Werror=maybe-uninitialized]
>   31 |     pcidev->dev = dev;
>      |     ~~~~~~~~~~~~^~~~~
> libxlu_pci.c:51:24: note: 'dev' was declared here
>   51 |     unsigned dom, bus, dev, func, vslot = 0;
>      |                        ^~~
> libxlu_pci.c:30:17: error: 'bus' may be used uninitialized in this
> function [-Werror=maybe-uninitialized]
>   30 |     pcidev->bus = bus;
>      |     ~~~~~~~~~~~~^~~~~
> libxlu_pci.c:51:19: note: 'bus' was declared here
>   51 |     unsigned dom, bus, dev, func, vslot = 0;
>      |                   ^~~
> libxlu_pci.c:29:20: error: 'dom' may be used uninitialized in this
> function [-Werror=maybe-uninitialized]
>   29 |     pcidev->domain = domain;
>      |     ~~~~~~~~~~~~~~~^~~~~~~~
> libxlu_pci.c:51:14: note: 'dom' was declared here
>   51 |     unsigned dom, bus, dev, func, vslot = 0;
>      |              ^~~
That looks like an issue I saw in Fedora which I associated to the update 
to gcc 10. It is one of the things I fixed (or at least worked around) in 
the patch here 
https://src.fedoraproject.org/rpms/xen/blob/master/f/xen.gcc10.fixes.patch
        Michael Young