NetBSD Problem Report #38170

From martin@duskware.de  Wed Mar  5 08:40:08 2008
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Date: Wed,  5 Mar 2008 05:15:34 +0000 (UTC)
From: abutter.gao@gmail.com
Reply-To: abutter.gao@gmail.com
To: netbsd-bugs-owner@NetBSD.org
Subject: Probable incorrect calculation of esym in multiboot.c on i386/amd64 platform
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>Number:         38170
>Category:       port-i386
>Synopsis:       Probable incorrect calculation of esym in multiboot.c on i386/amd64 platform
>Confidential:   no
>Severity:       non-critical
>Priority:       low
>Responsible:    jmmv
>State:          closed
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Wed Mar 05 08:45:01 +0000 2008
>Closed-Date:    Sat Mar 22 16:51:44 +0000 2008
>Last-Modified:  Sat Mar 22 16:55:02 +0000 2008
>Originator:     Gao Ya'nan
>Release:        NetBSD-4.0 and NetBSD-current
>Organization:
None
>Environment:
None
>Description:
When booting the NetBSD kernel by a Multiboot-compliant boot loader with MULTIBOOT_INFO_HAS_ELF_SYMS flag in mi_flags, the kernel will find symaddr and strtab and store the end of the last section between them to esym. But the esym is calculated as below :

*RELOC(int *, &esym) = (int)(strstart + strsize + KERNBASE);

so the 'esym' is just the end of strtab but not the "lowest 'free' address after the tables" when the symtab is copied behind the strtab.
>How-To-Repeat:
I just get is by the source code, so, sorry.
>Fix:
Add two new variables store the start address and the size of the last section, and update the esym by these two variables.

>Release-Note:

>Audit-Trail:

Responsible-Changed-From-To: port-i386-maintainer->jmmv
Responsible-Changed-By: wiz@NetBSD.org
Responsible-Changed-When: Wed, 05 Mar 2008 10:15:27 +0000
Responsible-Changed-Why:
jmmv wrote the code and agreed to look at this.


State-Changed-From-To: open->closed
State-Changed-By: jmmv@NetBSD.org
State-Changed-When: Sat, 22 Mar 2008 16:51:44 +0000
State-Changed-Why:
As far as I can tell, the code was indeed correct.  It is now fixed, thanks.


From: "Julio M. Merino Vidal" <jmmv@netbsd.org>
To: gnats-bugs@gnats.NetBSD.org
Cc: 
Subject: PR/38170 CVS commit: src/sys/arch/i386/i386
Date: Sat, 22 Mar 2008 16:50:17 +0000 (UTC)

 Module Name:	src
 Committed By:	jmmv
 Date:		Sat Mar 22 16:50:17 UTC 2008

 Modified Files:
 	src/sys/arch/i386/i386: multiboot.c

 Log Message:
 Fix esym calculation to match comments.  Reported by Gao Ya'nan in
 PR port-i386/38170.


 To generate a diff of this commit:
 cvs rdiff -r1.14 -r1.15 src/sys/arch/i386/i386/multiboot.c

 Please note that diffs are not public domain; they are subject to the
 copyright notices on the relevant files.

>Unformatted:

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