Re: [solved] Re: linux-next: build failure after merge of the perf tree

[Arnaldo Carvalho de Melo]

On Fri, Feb 23, 2024 at 12:34:40PM -0800, Namhyung Kim wrote:
> Hi Arnaldo,
> 
> On Fri, Feb 23, 2024 at 12:11 PM Arnaldo Carvalho de Melo
> <acme@xxxxxxxxxx> wrote:
> >
> > On Fri, Feb 23, 2024 at 04:50:47PM -0300, Arnaldo Carvalho de Melo wrote:
> > > On Thu, Feb 22, 2024 at 10:06:56AM +1100, Stephen Rothwell wrote:
> > > > Hi all,
> > > >
> > > > After merging the perf tree, today's linux-next build (native perf)
> > > > failed like this:
> > > >
> > > > util/bpf_skel/augmented_raw_syscalls.bpf.c:329:15: error: invalid application of 'sizeof' to an incomplete type 'struct timespec64'
> > > >         __u32 size = sizeof(struct timespec64);
> > > >                      ^     ~~~~~~~~~~~~~~~~~~~
> > > > util/bpf_skel/augmented_raw_syscalls.bpf.c:329:29: note: forward declaration of 'struct timespec64'
> > > >         __u32 size = sizeof(struct timespec64);
> > > >                                    ^
> > > >
> > > > Caused by commit
> > > >
> > > >   29d16de26df1 ("perf augmented_raw_syscalls.bpf: Move 'struct timespec64' to vmlinux.h")
> > > >
> > > > This is a ppc64 le build.
> > > >
> > > > I have used the perf tree from next-20240221 for today.
> > >
> > > Ok, finally I managed to secure a ppc64 machine to test this and
> > > sometimes I reproduce just like you reported, but sometimes I can't do
> > > it, didn't manage to isolate what is that makes it fail sometimes, make
> > > -C tools/perf clean, nuking the O= target directory, etc, when I
> > > reproduce it:
> >
> > So I think I see the problem, I now left the build directory with a
> > previous build from torvalds/master, then switched to the
> > perf-tools-branch and tried to build from there, without first removing
> > the old build, it fails:
> >
> >   CLANG   /tmp/build/perf-tools-next/util/bpf_skel/.tmp/augmented_raw_syscalls.bpf.o
> > util/bpf_skel/augmented_raw_syscalls.bpf.c:329:15: error: invalid application of 'sizeof' to an incomplete type 'struct timespec64'
> >   329 |         __u32 size = sizeof(struct timespec64);
> >       |                      ^     ~~~~~~~~~~~~~~~~~~~
> > util/bpf_skel/augmented_raw_syscalls.bpf.c:329:29: note: forward declaration of 'struct timespec64'
> >   329 |         __u32 size = sizeof(struct timespec64);
> >       |                                    ^
> > 1 error generated.
> > make[2]: *** [Makefile.perf:1161: /tmp/build/perf-tools-next/util/bpf_skel/.tmp/augmented_raw_syscalls.bpf.o] Error 1
> > make[1]: *** [Makefile.perf:264: sub-make] Error 2
> >
> >
> > Because it will use what was installed before in the build dir:
> >
> > [acme@ibm-p9z-16-lp5 perf-tools-next]$ ls -la /tmp/build/perf-tools-next/util/bpf_skel/vmlinux.h
> > -rw-r--r--. 1 acme acme 4319 Feb 23 14:59 /tmp/build/perf-tools-next/util/bpf_skel/vmlinux.h
> > [acme@ibm-p9z-16-lp5 perf-tools-next]$
> >
> > And that one doesn't have 'struct timespec64':
> >
> > [acme@ibm-p9z-16-lp5 perf-tools-next]$ grep timespec64 /tmp/build/perf-tools-next/util/bpf_skel/vmlinux.h
> > [acme@ibm-p9z-16-lp5 perf-tools-next]$
> >
> > If I remove that directory contents:
> >
> > [acme@ibm-p9z-16-lp5 perf-tools-next]$ rm -rf /tmp/build/perf-tools-next/
> > [acme@ibm-p9z-16-lp5 perf-tools-next]$ mkdir /tmp/build/perf-tools-next/
> > [acme@ibm-p9z-16-lp5 perf-tools-next]$
> >
> > And then try to build again:
> >
> > make -k O=/tmp/build/perf-tools-next/ -C tools/perf install-bin
> >
> > It works.
> >
> > I reproduced the problem on x86_64, so, on this transition period, the
> > problem happens, probably we need to robustify the installation of
> > tools/perf/util/bpf_skel/vmlinux/vmlinux.h in the O= target directory,
> > but if you just make sure the build directory is clean before trying to
> > build it, this time, it should work, wdyt?
> 
> Can we add a dependency to the minimal vmlinux.h?

That fixes it, I'll submit a formal patch

- Arnaldo
 
> Thanks,
> Namhyung
> 
> ---8<---
> diff --git a/tools/perf/Makefile.perf b/tools/perf/Makefile.perf
> index 3cecd51b2397..33621114135e 100644
> --- a/tools/perf/Makefile.perf
> +++ b/tools/perf/Makefile.perf
> @@ -1147,7 +1147,7 @@ ifeq ($(VMLINUX_H),)
>    endif
>  endif
> 
> -$(SKEL_OUT)/vmlinux.h: $(VMLINUX_BTF) $(BPFTOOL)
> +$(SKEL_OUT)/vmlinux.h: $(VMLINUX_BTF) $(BPFTOOL) $(VMLINUX_H)
>  ifeq ($(VMLINUX_H),)
>         $(QUIET_GEN)$(BPFTOOL) btf dump file $< format c > $@
>  else