From: "mark at klomp dot org" <sourceware-bugzilla@sourceware.org>
To: elfutils-devel@sourceware.org
Subject: [Bug binutils/23919] New: bfd doesn't handle ELF compressed data alignment
Date: Sat, 24 Nov 2018 22:09:00 -0000 [thread overview]
Message-ID: <bug-23919-10460@http.sourceware.org/bugzilla/> (raw)
https://sourceware.org/bugzilla/show_bug.cgi?id=23919
Bug ID: 23919
Summary: bfd doesn't handle ELF compressed data alignment
Product: binutils
Version: unspecified
Status: NEW
Severity: normal
Priority: P2
Component: binutils
Assignee: unassigned at sourceware dot org
Reporter: mark at klomp dot org
CC: devurandom at gmx dot net, elfutils-devel at sourceware dot org,
mark at klomp dot org, slyfox at inbox dot ru,
unassigned at sourceware dot org
Depends on: 23916
Target Milestone: ---
+++ This bug was initially created as a clone of Bug #23916 +++
The ELF compression header has a field (ch_addralign) that is set to the
alignment of the uncompressed section. This way the section itself can have a
different alignment than the decompressed section. bfd (and readelf) however
explicitly make the section sh_addralign and ch_addralign equal. It also always
sets the alignment to 1 which is wrong when using a Elf32_Chdr (which has
alignment of 4) or Elf64_Chdr (which has alignment of 8).
This shows up with tools that use elfutils libelf which sets up the alignment
correctly.
First gas creates a compressed section with on alignment of 1.
Second libelf accepts this, but corrects the alignment when it
writes out the section.
Third bfd_check_compression_header sanity checks the section alignment,
but it checks that the compressed and decompressed alignment is equal?!?
I think it wanted to check that the alignment is a power of 2 instead.
Referenced Bugs:
https://sourceware.org/bugzilla/show_bug.cgi?id=23916
[Bug 23916] [bisected] elifutils-0.175 broke kernel's objtool (elifutils-0.173
works)
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next reply other threads:[~2018-11-24 22:09 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-11-24 22:09 mark at klomp dot org [this message]
2018-11-24 22:27 ` [Bug binutils/23919] " mark at klomp dot org
2018-11-27 12:03 ` cvs-commit at gcc dot gnu.org
2018-11-27 12:06 ` nickc at redhat dot com
2018-11-27 12:22 ` mark at klomp dot org
2018-11-27 13:47 ` hjl.tools at gmail dot com
2018-11-27 14:06 ` cvs-commit at gcc dot gnu.org
2018-11-27 14:07 ` hjl.tools at gmail dot com
2018-11-28 13:55 ` ldv at sourceware dot org
2018-11-28 14:42 ` hjl.tools at gmail dot com
2018-11-28 14:57 ` mark at klomp dot org
2018-11-28 15:03 ` mark at klomp dot org
2018-12-02 13:46 ` cvs-commit at gcc dot gnu.org
2018-12-02 13:52 ` hjl.tools at gmail dot com
2018-12-05 11:55 ` mark at klomp dot org
2019-02-18 15:10 ` cvs-commit at gcc dot gnu.org
2019-02-26 20:12 ` cvs-commit at gcc dot gnu.org
2019-02-26 20:14 ` cvs-commit at gcc dot gnu.org
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