From: Jiri Slaby <jirislaby@kernel.org>
To: Andrii Nakryiko <andrii@kernel.org>,
dwarves@vger.kernel.org, acme@kernel.org
Cc: bpf@vger.kernel.org
Subject: Re: [PATCH dwarves] btf_encoder: ignore zero-sized ELF symbols
Date: Thu, 22 Oct 2020 07:19:32 +0200 [thread overview]
Message-ID: <9633d29b-887c-46ec-b131-adda8f69d722@kernel.org> (raw)
In-Reply-To: <20201021155220.1737964-1-andrii@kernel.org>
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>
> ---
> 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
next prev parent reply other threads:[~2020-10-22 5:19 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 [this message]
2020-10-23 16:37 ` Arnaldo Carvalho de Melo
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