From: Milian Wolff <milian.wolff@kdab.com>
To: elfutils-devel@sourceware.org
Cc: mark@klomp.org
Subject: Re: [PATCH] Fix CFI interpretation for locations on DW_CFA_*_loc boundaries
Date: Thu, 01 Nov 2018 09:12:00 -0000 [thread overview]
Message-ID: <1857278.YmUYHDWrPl@agathebauer> (raw)
In-Reply-To: <20181101084818.16153-1-milian.wolff@kdab.com>
[-- Attachment #1: Type: text/plain, Size: 1317 bytes --]
Please ignore this patch for now - I only looked at one specific case where
this changed the behavior to be in line with libunwind. Sadly, it breaks other
previously working situations. I need to look at this in more detail.
Cheers
On Donnerstag, 1. November 2018 09:48:18 CET Milian Wolff wrote:
> According to the DWARF v3 standard §6.4.3 3., all call frame
> instructions up to L1 <= L2 should be interpreted for an FDE.
> Elfutils currently only interprets L1 < L2, potentially missing
> some instructions when L1 directly points at a DW_CFA_*_loc boundary.
>
> This patch changes the behavior and makes elfutils behave like
> libunwind in that regard.
> ---
> libdw/cfi.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/libdw/cfi.c b/libdw/cfi.c
> index 341e055b..332c6b8b 100644
> --- a/libdw/cfi.c
> +++ b/libdw/cfi.c
> @@ -125,7 +125,7 @@ execute_cfi (Dwarf_CFI *cache,
> fs->regs[regno].value = (r_value); \
> } while (0)
>
> - while (program < end)
> + while (program <= end)
> {
> uint8_t opcode = *program++;
> Dwarf_Word regno;
--
Milian Wolff | milian.wolff@kdab.com | Senior Software Engineer
KDAB (Deutschland) GmbH, a KDAB Group company
Tel: +49-30-521325470
KDAB - The Qt, C++ and OpenGL Experts
[-- Attachment #2: smime.p7s --]
[-- Type: application/pkcs7-signature, Size: 3826 bytes --]
next prev parent reply other threads:[~2018-11-01 9:12 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-11-01 8:49 Milian Wolff
2018-11-01 9:12 ` Milian Wolff [this message]
2018-11-01 12:32 ` Milian Wolff
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=1857278.YmUYHDWrPl@agathebauer \
--to=milian.wolff@kdab.com \
--cc=elfutils-devel@sourceware.org \
--cc=mark@klomp.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 a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).