Em Thu, Jan 21, 2021 at 11:35:20AM +0000, Giuliano Procida escreveu:
> NOTE: Do not apply. I will try to eliminate the dependency on objcopy
> instead and achieve what's needed directly using libelf.
Ok, so I'll wait for the right fix.
Thanks for working on this!
- Arnaldo
> This is to avoid misaligned access when memory-mapping ELF sections.
>
> Signed-off-by: Giuliano Procida <gprocida@xxxxxxxxxx>
> ---
> libbtf.c | 8 ++++++++
> 1 file changed, 8 insertions(+)
>
> diff --git a/libbtf.c b/libbtf.c
> index 7552d8e..2f12d53 100644
> --- a/libbtf.c
> +++ b/libbtf.c
> @@ -797,6 +797,14 @@ static int btf_elf__write(const char *filename, struct btf *btf)
> goto unlink;
> }
>
> + snprintf(cmd, sizeof(cmd), "%s --set-section-alignment .BTF=16 %s",
> + llvm_objcopy, filename);
> + if (system(cmd)) {
> + /* non-fatal, this is a nice-to-have and it's only supported from LLVM 10 */
> + fprintf(stderr, "%s: warning: failed to align .BTF section in '%s': %d!\n",
> + __func__, filename, errno);
> + }
> +
> err = 0;
> unlink:
> unlink(tmp_fn);
> --
> 2.30.0.296.g2bfb1c46d8-goog
>
--
- Arnaldo
