[ovs-dev] [PATCH] travis: Fix 32-bit libunwind system build.

William Tu u9012063 at gmail.com
Fri Oct 4 00:34:59 UTC 2019


On Thu, Oct 3, 2019 at 10:15 AM Ilya Maximets <i.maximets at ovn.org> wrote:
>
> On 03.10.2019 18:13, Ilya Maximets wrote:
> > On 02.10.2019 20:15, William Tu wrote:
> >> 32-bit and 64-bit libunwind can not be installed at the same time.
> >> For 32-bit build, this patch removes the 64-bit libunwind and install
> >> 32-bit version.
> >>
> >> Tested-at: https://travis-ci.org/williamtu/ovs-travis/builds/592649311
> >> Fixes: e2ed6fbeb18c ("fatal-signal: Catch SIGSEGV and print backtrace.")
> >> Signed-off-by: William Tu <u9012063 at gmail.com>
> >> ---
> >>   .travis/linux-prepare.sh | 6 ++++++
> >>   1 file changed, 6 insertions(+)
> >>
> >> diff --git a/.travis/linux-prepare.sh b/.travis/linux-prepare.sh
> >> index 70fd98f715ed..164adf7ec4f8 100755
> >> --- a/.travis/linux-prepare.sh
> >> +++ b/.travis/linux-prepare.sh
> >> @@ -14,3 +14,9 @@ cd ..
> >>   pip install --disable-pip-version-check --user six flake8 hacking
> >>   pip install --user --upgrade docutils
> >> +
> >> +if [[ $BUILD_ENV =~ "-m32" ]]; then
> >> +    # 32-bit and 64-bit libunwind can not be installed at the same time.
> >> +    # This will remove the 64-bit libunwind and install 32-bit version.
> >> +    sudo apt-get install -y libunwind-dev:i386
> >> +fi
> >>
> >
> > Thanks for the new version.
> >
> > One thing I noticed is that without additional changes[1] this
> > patch just makes 'configure' script to fail the library check,
> > because 32bit library can't be linked with 64bit binary it checks:
> >
> >      checking for unw_backtrace in -lunwind... no
> >
> > But it should work as intended with the patch I posted:
> >
> > [1] https://patchwork.ozlabs.org/patch/1171259/
> >
> > Note that I replaced $BUILD_ENV with $M32 variable, so one of the
> > patches will need to be updated depending on the order of applying.
> > i.e. following diff should be squashed to one of them:
> >
> > -if [[ $BUILD_ENV =~ "-m32" ]]; then
> > +if [ "$M32" ]; then
> >
> > Other than that,
> > Acked-by: Ilya Maximets <i.maximets at ovn.org>
>
>
> Hmm, I tried to apply this patch and check the build and it
> failed:
>
> lib/backtrace.c: In function ‘log_received_backtrace’:
> lib/backtrace.c:105:23: error: format ‘%lx’ expects argument of type ‘long unsigned int’, but argument 4 has type ‘unw_word_t {aka unsigned int}’ [-Werror=format=]
>               VLOG_WARN("0x%016lx <%s+0x%lx>\n",
>                         ^
> ./include/openvswitch/vlog.h:277:41: note: in definition of macro ‘VLOG’
>               vlog(&this_module, level__, __VA_ARGS__);   \
>
> lib/backtrace.c:105:13: note: in expansion of macro ‘VLOG_WARN’
>               VLOG_WARN("0x%016lx <%s+0x%lx>\n",
>               ^
> lib/backtrace.c:105:23: error: format ‘%lx’ expects argument of type ‘long unsigned int’, but argument 6 has type ‘unw_word_t {aka unsigned int}’ [-Werror=format=]
>               VLOG_WARN("0x%016lx <%s+0x%lx>\n",
>                         ^
> ./include/openvswitch/vlog.h:277:41: note: in definition of macro ‘VLOG’
>               vlog(&this_module, level__, __VA_ARGS__);   \
>
> lib/backtrace.c:105:13: note: in expansion of macro ‘VLOG_WARN’
>
>               VLOG_WARN("0x%016lx <%s+0x%lx>\n",
>               ^
>
> Full log:
> https://travis-ci.org/igsilya/ovs/jobs/593132451

Thanks!
For 32-bit libunwind, the unw_word_t is defined as uint32_t, and
for 64-bit libunwind, it is defined as uint64_t.  Here actually it is printing
a pointer, so I will change it to use PRIxPTR

diff --git a/lib/backtrace.c b/lib/backtrace.c
index 9347634487c8..2853d5ff150d 100644
--- a/lib/backtrace.c
+++ b/lib/backtrace.c
@@ -102,7 +102,7 @@ log_received_backtrace(int fd) {
             if (backtrace[i].func[0] == 0) {
                 break;
             }
-            VLOG_WARN("0x%016lx <%s+0x%lx>\n",
+            VLOG_WARN("0x%016"PRIxPTR" <%s+0x%"PRIxPTR">\n",
                       backtrace[i].ip,
                       backtrace[i].func,
                       backtrace[i].offset);

I clone your upstream_freebsd_11.3 branch, and tested-at
https://travis-ci.org/williamtu/ovs-travis/builds/593284524

I will send a patch based on your patch.

Regards,
William


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