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From: Arnaldo Carvalho de Melo <acme@kernel.org>
To: Jiri Slaby <jirislaby@kernel.org>
Cc: Andrii Nakryiko <andrii@kernel.org>,
	dwarves@vger.kernel.org, bpf@vger.kernel.org
Subject: Re: [PATCH dwarves] btf_encoder: ignore zero-sized ELF symbols
Date: Fri, 23 Oct 2020 13:37:55 -0300	[thread overview]
Message-ID: <20201023163755.GA2406834@kernel.org> (raw)
In-Reply-To: <9633d29b-887c-46ec-b131-adda8f69d722@kernel.org>

Em Thu, Oct 22, 2020 at 07:19:32AM +0200, Jiri Slaby escreveu:
> On 21. 10. 20, 17:52, Andrii Nakryiko wrote:
> > It's legal for ELF symbol to have size 0, if it's size is unknown or
> > unspecified. Instead of erroring out, just ignore such symbols, as they can't
> > be a valid per-CPU variable anyways.
> > 
> > Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
> 
> Tested-by: Jiri Slaby <jirislaby@kernel.org>

thanks applied
 
> > ---
> >   btf_encoder.c | 12 ++++--------
> >   1 file changed, 4 insertions(+), 8 deletions(-)
> > 
> > diff --git a/btf_encoder.c b/btf_encoder.c
> > index 2a6455be4c52..2af1fe447834 100644
> > --- a/btf_encoder.c
> > +++ b/btf_encoder.c
> > @@ -287,6 +287,10 @@ static int find_all_percpu_vars(struct btf_elf *btfe)
> >   		if (!addr)
> >   			continue;
> > +		size = elf_sym__size(&sym);
> > +		if (!size)
> > +			continue; /* ignore zero-sized symbols */
> > +
> >   		sym_name = elf_sym__name(&sym, btfe->symtab);
> >   		if (!btf_name_valid(sym_name)) {
> >   			dump_invalid_symbol("Found symbol of invalid name when encoding btf",
> > @@ -295,14 +299,6 @@ static int find_all_percpu_vars(struct btf_elf *btfe)
> >   				continue;
> >   			return -1;
> >   		}
> > -		size = elf_sym__size(&sym);
> > -		if (!size) {
> > -			dump_invalid_symbol("Found symbol of zero size when encoding btf",
> > -					    sym_name, btf_elf__verbose, btf_elf__force);
> > -			if (btf_elf__force)
> > -				continue;
> > -			return -1;
> > -		}
> >   		if (btf_elf__verbose)
> >   			printf("Found per-CPU symbol '%s' at address 0x%lx\n", sym_name, addr);
> > 
> 
> 
> -- 
> js
> suse labs

-- 

- Arnaldo

      reply	other threads:[~2020-10-23 16:38 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-10-21 15:52 [PATCH dwarves] btf_encoder: ignore zero-sized ELF symbols Andrii Nakryiko
2020-10-22  5:19 ` Jiri Slaby
2020-10-23 16:37   ` Arnaldo Carvalho de Melo [this message]

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