public inbox for libabigail@sourceware.org
 help / color / mirror / Atom feed
From: Dodji Seketeli <dodji@seketeli.org>
To: Mark Wielaard <mark@klomp.org>
Cc: Ben Woodard <woodard@redhat.com>,
	 Ben Woodard via Libabigail <libabigail@sourceware.org>
Subject: Re: libabigail 2.1 trunk testing where are we?
Date: Tue, 20 Sep 2022 10:47:37 +0200	[thread overview]
Message-ID: <87y1ue5t5i.fsf@seketeli.org> (raw)
In-Reply-To: <YuRJpWXXz+I/BI08@wildebeest.org> (Mark Wielaard's message of "Fri, 29 Jul 2022 22:57:09 +0200")

Hello fine fellows!

Mark Wielaard <mark@klomp.org> a écrit:

> On Fri, Jul 29, 2022 at 11:28:18AM -0700, Ben Woodard via Libabigail wrote:
>> 1 crash due to incorrect ELF in that shows up in a small number of
>> packages https://sourceware.org/bugzilla/show_bug.cgi?id=29346
>
> I have a patch that should work around that on:
> https://code.wildebeest.org/git/user/mjw/libabigail/commit/?h=pr29346
> Also attached. Maybe someone with commit access could push it to a
> users try branch for testing?

Man, thank you!

[...]

Ben Woodard via Libabigail <libabigail@sourceware.org> a écrit:

> Thanks for the patch.
>
> I put it into my personal develop tree and it relatively immediately
> fixed 4/6 of the packages that I had identified as having that
> problem. The tests on the other two packages are still running and
> have been running for over half an hour and so something is
> working. We will see if they complete before they timeout. I may have
> to move those two to the takes to long to compete group
> https://sourceware.org/bugzilla/show_bug.cgi?id=29303
>
> So this at least fixed:
> guile22
> guile30
> gnucash
> aisleriot

Whoah!

Thank you Ben!

You guys rock.

Okay, so I have just applied this to master.

Mark, by the, way, just for my own education, would it have been ok to
just use gelf_getshdr all the time, rather than using looking at the
sh_entsize property of the section header that can be wrong sometimes?

I am guessing the reason why you chose to keep looking at the later has
to do with potential performance concerns?

Anyway, either way, I am fine.

Here is what got applied exactly:

From f3b889a2cb94f8bb8372db14520d235dda7fdc3b Mon Sep 17 00:00:00 2001
From: Mark Wielaard <mark@klomp.org>
Date: Wed, 20 Jul 2022 01:01:14 +0200
Subject: [PATCH] Handle zero sh_entsize in get_soname_of_elf_file

Apparently guile produced ELF files don't set sh_entsize for the
dynamic section. Which would cause a divide by zero. Luckily we do
know how big an dynamic entry should be. So use gelf_fsize for
ELF_T_DYN if sh_entsize is zero.

	  * src/abg-dwarf-reader.cc (get_soname_of_elf_file):
	  Make sure entsize is non-zero before use.

https://sourceware.org/bugzilla/show_bug.cgi?id=29346

Signed-off-by: Mark Wielaard <mark@klomp.org>
Signed-off-by: Dodji Seketeli <dodji@redhat.com>
---
 src/abg-dwarf-reader.cc | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/src/abg-dwarf-reader.cc b/src/abg-dwarf-reader.cc
index 56909540..695683ed 100644
--- a/src/abg-dwarf-reader.cc
+++ b/src/abg-dwarf-reader.cc
@@ -16425,8 +16425,11 @@ get_soname_of_elf_file(const string& path, string &soname)
           Elf_Scn* scn = gelf_offscn (elf, phdr->p_offset);
           GElf_Shdr shdr_mem;
           GElf_Shdr* shdr = gelf_getshdr (scn, &shdr_mem);
+          size_t entsize = (shdr != NULL && shdr->sh_entsize != 0
+                            ? shdr->sh_entsize
+                            : gelf_fsize (elf, ELF_T_DYN, 1, EV_CURRENT));
           int maxcnt = (shdr != NULL
-                        ? shdr->sh_size / shdr->sh_entsize : INT_MAX);
+                        ? shdr->sh_size / entsize : INT_MAX);
           ABG_ASSERT (shdr == NULL || shdr->sh_type == SHT_DYNAMIC);
           Elf_Data* data = elf_getdata (scn, NULL);
           if (data == NULL)
-- 
2.37.2

[...]

Cheers,

-- 
		Dodji

  parent reply	other threads:[~2022-09-20  8:47 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-07-29 18:28 Ben Woodard
2022-07-29 20:57 ` Mark Wielaard
2022-07-29 22:48   ` Ben Woodard
2022-09-20  8:47   ` Dodji Seketeli [this message]
2022-09-20 15:05     ` Mark Wielaard
2022-09-25  7:06       ` Dodji Seketeli

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=87y1ue5t5i.fsf@seketeli.org \
    --to=dodji@seketeli.org \
    --cc=libabigail@sourceware.org \
    --cc=mark@klomp.org \
    --cc=woodard@redhat.com \
    /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).