Re: linux-next failing build due to missing cubictcp_state symbol

[Jiri Slaby]

On 30. 04. 21, 19:47, Michal Suchánek wrote:
> CC another Jiri
>
> On Tue, Apr 27, 2021 at 02:12:37PM +0200, Michal Suchánek wrote:
> > On Mon, Apr 26, 2021 at 09:16:36PM +0200, Jiri Olsa wrote:
> > > On Mon, Apr 26, 2021 at 06:03:19PM +0200, Jiri Olsa wrote:
> > > > On Mon, Apr 26, 2021 at 08:41:49AM -0700, Yonghong Song wrote:
> > > > > On 4/26/21 5:14 AM, Michal Suchánek wrote:
> > > > > > On Mon, Apr 26, 2021 at 02:12:20PM +0200, Michal Suchánek wrote:
> > > > > > > On Mon, Apr 26, 2021 at 01:32:15PM +0200, Michal Suchánek wrote:
> > > > > > > > On Sun, Apr 25, 2021 at 01:15:45PM +0200, Michal Suchánek wrote:
> > > > > > > > > On Fri, Apr 23, 2021 at 07:55:28PM +0200, Michal Suchánek wrote:
> > > > > > > > > > On Fri, Apr 23, 2021 at 07:41:29AM -0700, Yonghong Song wrote:
> > > > > > > > > > > On 4/23/21 6:05 AM, Michal Suchánek wrote:
> > > > > > > > > > > > Hello,
> > > > > > > > > > > >
> > > > > > > > > > > > I see this build error in linux-next (config attached).
> > > > > > > > > > > >
> > > > > > > > > > > > [ 4939s]   LD      vmlinux
> > > > > > > > > > > > [ 4959s]   BTFIDS  vmlinux
> > > > > > > > > > > > [ 4959s] FAILED unresolved symbol cubictcp_state
> > > > > > > > > > > > [ 4960s] make[1]: ***
> > > > > > > > > > > > [/home/abuild/rpmbuild/BUILD/kernel-vanilla-5.12~rc8.next.20210422/linux-5.12-rc8-next-20210422/Makefile:1277:
> > > > > > > > > > > > vmlinux] Error 255
> > > > > > > > > > > > [ 4960s] make: *** [../Makefile:222: __sub-make] Error 2
> > > >
> > > > this one was reported by Jesper and was fixed by upgrading pahole
> > > > that contains the new function generation fixes (v1.19)
> > > >
> > > > > > > > > > > Looks like you have DYNAMIC_FTRACE config option enabled already.
> > > > > > > > > > > Could you try a later version of pahole?
> > > > > > > > > >
> > > > > > > > > > Is this requireent new?
> > > > > > > > > >
> > > > > > > > > > I have pahole 1.20, and master does build without problems.
> > > > > > > > > >
> > > > > > > > > > If newer version is needed can a check be added?
> > > > > > > > >
> > > > > > > > > With dwarves 1.21 some architectures are fixed and some report other
> > > > > > > > > missing symbol. Definitely an improvenent.
> > > > > > > > >
> > > > > > > > > I see some new type support was added so it makes sense if that type is
> > > > > > > > > used the new dwarves are needed.
> > > > > > > >
> > > > > > > > Ok, here is the current failure with dwarves 1.21 on 5.12:
> > > > > > > >
> > > > > > > > [ 2548s]   LD      vmlinux
> > > > > > > > [ 2557s]   BTFIDS  vmlinux
> > > > > > > > [ 2557s] FAILED unresolved symbol vfs_truncate
> > > > > > > > [ 2558s] make[1]: ***
> > > > > > > > [/home/abuild/rpmbuild/BUILD/kernel-kvmsmall-5.12.0/linux-5.12/Makefile:1213:
> > > > > > > > vmlinux] Error 255
> > > > >
> > > > > This is PPC64, from attached config:
> > > > >    CONFIG_PPC64=y
> > > > > I don't have environment to cross-compile for PPC64.
> > > > > Jiri, could you take a look? Thanks!
> > > >
> > > > looks like vfs_truncate did not get into BTF data,
> > > > I'll try to reproduce

_None_ of the functions are generated by pahole -J from debuginfo on 
ppc64. debuginfo appears to be correct. Neither pahole -J fs/open.o 
works correctly. collect_functions in dwarves seems to be defunct on 
ppc64... "functions" array is bogus (so find_function -- the bsearch -- 
fails). I didn't have more time to continue debugging. This is where I 
stopped.

regards,
--
js
suse labs