Bug 511187 - kernel: build with -fno-delete-null-pointer-checks [mrg-1]
Summary: kernel: build with -fno-delete-null-pointer-checks [mrg-1]
Keywords:
Status: CLOSED ERRATA
Alias: None
Product: Red Hat Enterprise MRG
Classification: Red Hat
Component: realtime-kernel
Version: Development
Hardware: All
OS: Linux
urgent
high
Target Milestone: 1.1.8
: ---
Assignee: Luis Claudio R. Goncalves
QA Contact: David Sommerseth
URL:
Whiteboard:
Depends On: 511181
Blocks:
TreeView+ depends on / blocked
 
Reported: 2009-07-14 04:40 UTC by Eugene Teo (Security Response)
Modified: 2016-05-22 23:28 UTC (History)
4 users (show)

Fixed In Version:
Doc Type: Bug Fix
Doc Text:
Clone Of: 511181
Environment:
Last Closed: 2009-09-01 07:38:52 UTC
Target Upstream Version:
Embargoed:


Attachments (Terms of Use)


Links
System ID Private Priority Status Summary Last Updated
Red Hat Product Errata RHSA-2009:1239 0 normal SHIPPED_LIVE Important: kernel-rt security and bug fix update 2009-09-01 07:38:14 UTC

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


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