On Thu, 2024-12-19 at 17:31 +1100, Stephen Rothwell wrote:
> Hi all,
>
> On Wed, 11 Dec 2024 14:37:01 +1100 Stephen Rothwell <sfr@xxxxxxxxxxxxxxxx> wrote:
> >
> > After merging the vfs-brauner tree, today's linux-next build (powerpc
> > allyesconfig) produced these warnings:
> >
> > samples/vfs/mountinfo.c: In function 'show_propagation':
> > samples/vfs/mountinfo.c:104:36: warning: format '%llu' expects argument of type 'long long unsigned int', but argument 2 has type '__u64' {aka 'long unsigned int'} [-Wformat=]
> > 104 | printf(" shared:%llu", sm->mnt_peer_group);
> > | ~~~^ ~~~~~~~~~~~~~~~~~~
> > | | |
> > | | __u64 {aka long unsigned int}
> > | long long unsigned int
> > | %lu
> > samples/vfs/mountinfo.c:106:36: warning: format '%llu' expects argument of type 'long long unsigned int', but argument 2 has type '__u64' {aka 'long unsigned int'} [-Wformat=]
> > 106 | printf(" master:%llu", sm->mnt_master);
> > | ~~~^ ~~~~~~~~~~~~~~
> > | | |
> > | | __u64 {aka long unsigned int}
> > | long long unsigned int
> > | %lu
> > samples/vfs/mountinfo.c:108:52: warning: format '%llu' expects argument of type 'long long unsigned int', but argument 2 has type '__u64' {aka 'long unsigned int'} [-Wformat=]
> > 108 | printf(" propagate_from:%llu", sm->propagate_from);
> > | ~~~^ ~~~~~~~~~~~~~~~~~~
> > | | |
> > | | __u64 {aka long unsigned int}
> > | long long unsigned int
> > | %lu
> > samples/vfs/mountinfo.c: In function 'dump_mountinfo':
> > samples/vfs/mountinfo.c:144:42: warning: format '%llx' expects argument of type 'long long unsigned int', but argument 4 has type '__u64' {aka 'long unsigned int'} [-Wformat=]
> > 144 | printf("0x%lx 0x%lx 0x%llx ", mnt_ns_id, mnt_id, buf->mnt_parent_id);
> > | ~~~^ ~~~~~~~~~~~~~~~~~~
> > | | |
> > | long long unsigned int __u64 {aka long unsigned int}
> > | %lx
> >
> > Introduced by commits
> >
> > 0c8f746452aa ("samples: add a mountinfo program to demonstrate statmount()/listmount()")
> > ee8c840a4a35 ("samples: fix missing nodiratime option and handle propagate_from correctly")
> >
> > I am not sure why these warnings only turned up today.
>
> I am still seeing these warnings.
I'm not sure how to fix this the right way.
The problem seems to be a discrepancy in the __u64 type between arches.
Changing these in a way that would make PPC happy causes these warnings
on x86_64:
gcc -Wp,-MMD,./.mountinfo.d -Wall -Wmissing-prototypes -Wstrict-prototypes -O2 -fomit-frame-pointer -std=gnu11 -m64 -I usr/include -m64 -o mountinfo mountinfo.c
mountinfo.c: In function ‘show_propagation’:
mountinfo.c:104:35: warning: format ‘%lu’ expects argument of type ‘long unsigned int’, but argument 2 has type ‘__u64’ {aka ‘long long unsigned int’} [-Wformat=]
104 | printf(" shared:%lu", sm->mnt_peer_group);
| ~~^ ~~~~~~~~~~~~~~~~~~
| | |
| | __u64 {aka long long unsigned int}
| long unsigned int
| %llu
mountinfo.c:106:35: warning: format ‘%lu’ expects argument of type ‘long unsigned int’, but argument 2 has type ‘__u64’ {aka ‘long long unsigned int’} [-Wformat=]
106 | printf(" master:%lu", sm->mnt_master);
| ~~^ ~~~~~~~~~~~~~~
| | |
| | __u64 {aka long long unsigned int}
| long unsigned int
| %llu
mountinfo.c:108:51: warning: format ‘%lu’ expects argument of type ‘long unsigned int’, but argument 2 has type ‘__u64’ {aka ‘long long unsigned int’} [-Wformat=]
108 | printf(" propagate_from:%lu", sm->propagate_from);
| ~~^ ~~~~~~~~~~~~~~~~~~
| | |
| | __u64 {aka long long unsigned int}
| long unsigned int
| %llu
mountinfo.c: In function ‘dump_mountinfo’:
mountinfo.c:144:41: warning: format ‘%lx’ expects argument of type ‘long unsigned int’, but argument 4 has type ‘__u64’ {aka ‘long long unsigned int’} [-Wformat=]
144 | printf("0x%lx 0x%lx 0x%lx ", mnt_ns_id, mnt_id, buf->mnt_parent_id);
| ~~^ ~~~~~~~~~~~~~~~~~~
| | |
| long unsigned int __u64 {aka long long unsigned int}
| %llx
What format specifier should we be using that would make both arches happy?
Thanks,
--
Jeff Layton <jlayton@xxxxxxxxxx>
