Bug 65176

Summary:	broken urandom (PATCH INCLUDED)
Product:	[Retired] Red Hat Linux	Reporter:	Gigs <jgiglio>
Component:	kernel	Assignee:	Arjan van de Ven <arjanv>
Status:	CLOSED RAWHIDE	QA Contact:	Brian Brock <bbrock>
Severity:	medium	Docs Contact:
Priority:	high
Version:	7.3
Target Milestone:	---
Target Release:	---
Hardware:	All
OS:	Linux
Whiteboard:
Fixed In Version:		Doc Type:	Bug Fix
Doc Text:		Story Points:	---
Clone Of:		Environment:
Last Closed:	2002-05-19 22:13:29 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:

Description Gigs 2002-05-19 13:09:33 UTC

Description of Problem:
/dev/urandom is broken by some lowlatency code that is apparently incorrect. 
It causes read calls to urandom to return incomplete.

Version-Release number of selected component (if applicable):
Kernel 2.4.18-3

How Reproducible:
Always

Steps to Reproduce:
1.  dd if=/dev/urandom of=/tmp/testfile bs=1M count=1
2.  
3.  

Actual Results:
testfile is very small, 1M is requested, several kilobytes is returned

Expected Results:
1M file o garbage

Additional Information:
	
--- random.c.orig	Thu Apr 18 06:50:33 2002
+++ random.c	Sun May 19 08:40:14 2002
@@ -1371,8 +1371,7 @@
 		add_timer_randomness(&extract_timer_state, nbytes);
 #if LOWLATENCY_NEEDED
 		/* This can happen in softirq's, but that's what we want */
-		if (conditional_schedule_needed())
-			break;
+		conditional_schedule();
 #endif
 	}

Comment 1 Gigs 2002-05-19 22:13:24 UTC

Andrew Morton said:
>Yeah, unfortunately it's called under spinlock, so we can't schedule
>from there (I think).
>I guess I'll just remove that chunk - it's only worth a millisecond or
>so anyway.

So ignore the patch I gave and just remove the whole  #if LOWLATENCY_NEEDED.

Comment 2 Arjan van de Ven 2002-05-21 08:29:42 UTC

thanks for the report! Fixed for the next build