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Bug 511187

Summary:	kernel: build with -fno-delete-null-pointer-checks [mrg-1]
Product:	Red Hat Enterprise MRG	Reporter:	Eugene Teo (Security Response) <eteo>
Component:	realtime-kernel	Assignee:	Luis Claudio R. Goncalves <lgoncalv>
Status:	CLOSED ERRATA	QA Contact:	David Sommerseth <davids>
Severity:	high	Docs Contact:
Priority:	urgent
Version:	Development	CC:	bhu, lgoncalv, ovasik, williams
Target Milestone:	1.1.8
Target Release:	---
Hardware:	All
OS:	Linux
Whiteboard:
Fixed In Version:		Doc Type:	Bug Fix
Doc Text:		Story Points:	---
Clone Of:	511181	Environment:
Last Closed:	2009-09-01 07:38:52 UTC	Type:	---
Regression:	---	Mount Type:	---
Documentation:	---	CRM:
Verified Versions:		Category:	---
oVirt Team:	---	RHEL 7.3 requirements from Atomic Host:
Cloudforms Team:	---	Target Upstream Version:
Embargoed:
Bug Depends On:	511181
Bug Blocks:

Description Eugene Teo (Security Response) 2009-07-14 04:40:42 UTC

+++ This bug was initially created as a clone of Bug #511181 +++

Description of problem:
http://gcc.gnu.org/onlinedocs/gcc-4.1.2/gcc/Optimize-Options.html

-fdelete-null-pointer-checks
    Use global dataflow analysis to identify and eliminate useless checks for null pointers. The compiler assumes that dereferencing a null pointer would have halted the program. If a pointer is checked after it has already been dereferenced, it cannot be null.

    In some environments, this assumption is not true, and programs can safely dereference null pointers. Use -fno-delete-null-pointer-checks to disable this optimization for programs which depend on that behavior.

    Enabled at levels -O2, -O3, -Os.

Comment 2 Eugene Teo (Security Response) 2009-07-17 00:23:36 UTC

Upstream commit:
http://git.kernel.org/linus/a3ca86aea507904148870946d599e07a340b39bf

Comment 3 Luis Claudio R. Goncalves 2009-08-20 20:56:57 UTC

Patch added to kernel -130

Comment 4 David Sommerseth 2009-08-26 17:01:00 UTC

Verified by code review.  Found upstream commit a3ca86aea507904148870946d599e07a340b39bf as mrg-rt.git commit ee25b4c4be4adad44a837c16ef7680d0b970b353 implemented as add_-fno-delete-null-pointer-checks_to_CFLAGS.patch in the kernel-rt-2.6.24.7-132 source RPM.

Comment 6 errata-xmlrpc 2009-09-01 07:38:52 UTC

An advisory has been issued which should help the problem
described in this bug report. This report is therefore being
closed with a resolution of ERRATA. For more information
on therefore solution and/or where to find the updated files,
please follow the link below. You may reopen this bug report
if the solution does not work for you.

http://rhn.redhat.com/errata/RHSA-2009-1239.html