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Bug 607261

Summary: Read from /proc/xen/xenbus does not honor O_NONBLOCK
Product: Red Hat Enterprise Linux 4 Reporter: Paolo Bonzini <pbonzini>
Component: kernel-xenAssignee: Paolo Bonzini <pbonzini>
Status: CLOSED ERRATA QA Contact: Virtualization Bugs <virt-bugs>
Severity: low Docs Contact:
Priority: low    
Version: 4.9CC: clalance, drjones, mjenner, qcai, xen-maint, yuzhang
Target Milestone: rc   
Target Release: ---   
Hardware: All   
OS: Linux   
Whiteboard:
Fixed In Version: Doc Type: Bug Fix
Doc Text:
Story Points: ---
Clone Of: 470801 Environment:
Last Closed: 2011-02-16 16:06:07 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: 470801    
Bug Blocks: 458302    

Comment 1 Paolo Bonzini 2010-06-24 16:07:24 UTC
reproducer:

#include <stdlib.h>
#include <errno.h>
#include <fcntl.h>
#include <unistd.h>
int main()
{
  char buf[256];
  int fd = open ("/proc/xen/xenbus", O_RDONLY | O_NONBLOCK); 
  if (fd == -1) {
    perror ("/proc/xen/xenbus");
    exit (1);
  }
  alarm (5);
  while (read (fd, buf, 256) == -1 && errno != EAGAIN)
    ;
  puts ("works");
  exit (0);
}

Comment 3 RHEL Program Management 2010-10-12 17:50:57 UTC
This request was evaluated by Red Hat Product Management for inclusion in a Red
Hat Enterprise Linux maintenance release.  Product Management has requested
further review of this request by Red Hat Engineering, for potential
inclusion in a Red Hat Enterprise Linux Update release for currently deployed
products.  This request is not yet committed for inclusion in an Update
release.

Comment 4 Vivek Goyal 2010-10-13 16:13:39 UTC
Committed in 89.42.EL . RPMS are available at http://people.redhat.com/vgoyal/rhel4/

Comment 7 Yufang Zhang 2010-12-16 06:51:21 UTC
QA verified this bug with kernel-xenU-2.6.9-93.EL:

Compile the reproducer in the guest and execute it. output is 'works'.

Comment 8 errata-xmlrpc 2011-02-16 16:06:07 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-2011-0263.html