Bug 84226 – htons() broken for Pentium 4

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Bug 84226 - htons() broken for Pentium 4

Summary:	htons() broken for Pentium 4

Status:	CLOSED NOTABUG

Aliases:	None

Product:	Red Hat Linux
Classification:	Retired
Component:	glibc (Show other bugs)
Sub Component:
Version:	8.0
Hardware:	other Linux

Priority	medium Severity high
Target Milestone:	---
Target Release:	---
Assigned To:	Jakub Jelinek
QA Contact:	Brian Brock
Docs Contact:

URL:
Whiteboard:
Keywords:

Depends On:
Blocks:
	Show dependency tree / graph

Reported:	2003-02-13 12:54 EST by Matt Peterson
Modified:	2016-11-24 10:24 EST (History)
CC List:	1 user (show)

See Also:
Fixed In Version:
Doc Type:	Bug Fix
Doc Text:
Story Points:	---
Clone Of:
Environment:
Last Closed:	2003-02-13 15:00:12 EST
Type:	---
Regression:	---
Mount Type:	---
Documentation:	---
CRM:
Verified Versions:
Category:	---
oVirt Team:	---
RHEL 7.3 requirements from Atomic Host:
Cloudforms Team:	---

Attachments	(Terms of Use)
Short test program that uses htons() to build packet buffer (1.57 KB, text/plain) 2003-02-13 12:59 EST, Matt Peterson	no flags	Details
Add an attachment (proposed patch, testcase, etc.)

Groups: None (edit)

Description Matt Peterson 2003-02-13 12:54:08 EST

From Bugzilla Helper:
User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.0.1) Gecko/20021003

Description of problem:
It appears as though the htons implementation has some problems on Pentium 4.  I
have attached the code for a small test program based on code from the OpenSLP
project.  

You'll notice that the buffer generation on RedHat 7.3 differs from Redhat 8.0.
 You'll also notice that buffer generation differs between Pentium 2/3 and
Pentium 4.


Version-Release number of selected component (if applicable):


How reproducible:
Always

Steps to Reproduce:
1.compile program on RH 7.3 and RH 8.0 and compare output
2.compile program on RH 8.0 and compare output when run on Pentium 3 and Pentium 4

    

Actual Results:  
Redhat 7.3 produces correctly formatted buffer.
Redhat 8.0 on Pentium 2/3 produces correctly formatted buffer
Redhat 8.0/8.1 beta produces INCORRECTLY formatted buffer

Expected Results:  
Code generation for htons() should be compatible across pentium family such that
use of htns() to format packet buffers is source/binary compatible across Redhat
distros and all pentium architectures

Additional info: See attached htons_test.c file

Comment 1 Matt Peterson 2003-02-13 12:58:05 EST

Actual results (should say)
Redhat 8.0/8.1 on Pentium 4 beta produces INCORRECTLY formatted buffer

Comment 2 Matt Peterson 2003-02-13 12:59:39 EST

Created attachment 90058 [details]
Short test program that uses htons() to build packet buffer

Comment 3 Jakub Jelinek 2003-02-13 15:00:12 EST

This program has undefined behaviour, see info gcc on -fstrict-aliasing.
You cannot access one memory location (in your testcase char[3]) through
two different pointers which may not alias.

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