From: Arnaldo Carvalho de Melo <acme@kernel.org>
To: Douglas RAILLARD <douglas.raillard@arm.com>
Cc: acme@redhat.com, dwarves@vger.kernel.org
Subject: Re: [PATCH v2 2/3] btf_loader.c: Refactor class__fixup_btf_bitfields
Date: Thu, 21 Oct 2021 17:49:21 -0300 [thread overview]
Message-ID: <YXHSUaINccYHpmya@kernel.org> (raw)
In-Reply-To: <20211018131621.212628-3-douglas.raillard@arm.com>
Em Mon, Oct 18, 2021 at 02:16:20PM +0100, Douglas RAILLARD escreveu:
> From: Douglas Raillard <douglas.raillard@arm.com>
>
> Refactor class__fixup_btf_bitfields to remove a "continue" statement, to
> prepare the ground for alignment fixup that is relevant for some types
> matching:
>
> type->tag != DW_TAG_base_type && type->tag != DW_TAG_enumeration_type
Thanks, applied.
Committer testing:
btfdiff passes for a x86_64 kernel built with gcc and for a clang
thin-LTO vmlinux build.
- Arnaldo
> Signed-off-by: Douglas Raillard <douglas.raillard@arm.com>
> ---
> btf_loader.c | 29 ++++++++++++++---------------
> 1 file changed, 14 insertions(+), 15 deletions(-)
>
> diff --git a/btf_loader.c b/btf_loader.c
> index 3e5a945..9c2daee 100644
> --- a/btf_loader.c
> +++ b/btf_loader.c
> @@ -486,28 +486,27 @@ static int class__fixup_btf_bitfields(struct tag *tag, struct cu *cu)
> pos->byte_size = tag__size(type, cu);
> pos->bit_size = pos->byte_size * 8;
>
> - /* bitfield fixup is needed for enums and base types only */
> - if (type->tag != DW_TAG_base_type && type->tag != DW_TAG_enumeration_type)
> - continue;
> -
> /* if BTF data is incorrect and has size == 0, skip field,
> * instead of crashing */
> if (pos->byte_size == 0) {
> continue;
> }
>
> - if (pos->bitfield_size) {
> - /* bitfields seem to be always aligned, no matter the packing */
> - pos->byte_offset = pos->bit_offset / pos->bit_size * pos->bit_size / 8;
> - pos->bitfield_offset = pos->bit_offset - pos->byte_offset * 8;
> - /* re-adjust bitfield offset if it is negative */
> - if (pos->bitfield_offset < 0) {
> - pos->bitfield_offset += pos->bit_size;
> - pos->byte_offset -= pos->byte_size;
> - pos->bit_offset = pos->byte_offset * 8 + pos->bitfield_offset;
> + /* bitfield fixup is needed for enums and base types only */
> + if (type->tag == DW_TAG_base_type || type->tag == DW_TAG_enumeration_type) {
> + if (pos->bitfield_size) {
> + /* bitfields seem to be always aligned, no matter the packing */
> + pos->byte_offset = pos->bit_offset / pos->bit_size * pos->bit_size / 8;
> + pos->bitfield_offset = pos->bit_offset - pos->byte_offset * 8;
> + /* re-adjust bitfield offset if it is negative */
> + if (pos->bitfield_offset < 0) {
> + pos->bitfield_offset += pos->bit_size;
> + pos->byte_offset -= pos->byte_size;
> + pos->bit_offset = pos->byte_offset * 8 + pos->bitfield_offset;
> + }
> + } else {
> + pos->byte_offset = pos->bit_offset / 8;
> }
> - } else {
> - pos->byte_offset = pos->bit_offset / 8;
> }
> }
>
> --
> 2.25.1
--
- Arnaldo
next prev parent reply other threads:[~2021-10-21 20:49 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-10-18 13:16 [PATCH v2 0/3] Infer BTF alignment Douglas RAILLARD
2021-10-18 13:16 ` [PATCH v2 1/3] fprintf: Fix nested struct printing Douglas RAILLARD
2021-10-18 13:16 ` [PATCH v2 2/3] btf_loader.c: Refactor class__fixup_btf_bitfields Douglas RAILLARD
2021-10-21 20:49 ` Arnaldo Carvalho de Melo [this message]
2021-10-18 13:16 ` [PATCH v2 3/3] btf_loader.c: Infer alignment info Douglas RAILLARD
2021-10-22 0:31 ` Arnaldo Carvalho de Melo
2021-10-25 17:06 ` Arnaldo Carvalho de Melo
2021-10-26 15:03 ` Douglas Raillard
2021-10-27 20:47 ` Arnaldo Carvalho de Melo
2021-10-28 9:31 ` Douglas Raillard
2021-10-28 11:38 ` Arnaldo Carvalho de Melo
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=YXHSUaINccYHpmya@kernel.org \
--to=acme@kernel.org \
--cc=acme@redhat.com \
--cc=douglas.raillard@arm.com \
--cc=dwarves@vger.kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.