Re: build failure after commit eb0481bbc4ce ("objtool: Fix reloc_hash size")

From: Josh Poimboeuf
Date: Wed Jun 28 2023 - 13:05:37 EST


On Wed, Jun 28, 2023 at 06:45:54PM +0200, Michal Kubecek wrote:
> On Wed, Jun 28, 2023 at 06:06:31PM +0200, Michal Kubecek wrote:
> > On Wed, Jun 28, 2023 at 05:44:32PM +0200, Michal Kubecek wrote:
> > > On Wed, Jun 28, 2023 at 08:16:54AM -0700, Josh Poimboeuf wrote:
> > > > Interesting. Can you add the below patch and also do:
> > > >
> > > > make net/ipv4/netfilter/iptable_nat.o OBJTOOL_ARGS="--stats"
> > > >
> > > > and report the output?
> > >
> > > With these, I get
> > >
> > > ...
> > > CC [M] net/ipv4/netfilter/iptable_nat.o
> > > nr_sections: 40
> > > section_bits: 10
> > > nr_symbols: 41
> > > symbol_bits: 10
> > > mmap reloc: Invalid argument
> > > make[1]: Leaving directory '/srv/ram/kobj'
> >
> > Not sure if it's of any use but I also tried to run it under strace and
> > the failed mmap() call seems to be
> >
> > 18761 mmap(NULL, 0, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = -1 EINVAL (Invalid argument)
> >
> > Perhaps the problem could be that elf->num_relocs may be zero?
>
> I added a printf() and got
>
> size = -4991471925827290382 = 0xbababababababaf2
>
> for the elf_alloc_hash() invocation resulting in failed mmap().

Wut. Can you share the .o file?

--
Josh