Bug 309461

Summary: utrace: tkill(SIGCONT) is not reported by waitpid() under ptrace
Product: Red Hat Enterprise Linux 5 Reporter: Jan Kratochvil <jan.kratochvil>
Component: kernelAssignee: Roland McGrath <roland>
Status: CLOSED ERRATA QA Contact: Martin Jenner <mjenner>
Severity: medium Docs Contact:
Priority: medium    
Version: 5.1CC: dzickus
Target Milestone: betaKeywords: Regression
Target Release: ---   
Hardware: All   
OS: Linux   
Whiteboard:
Fixed In Version: RHBA-2008-0314 Doc Type: Bug Fix
Doc Text:
Story Points: ---
Clone Of: Environment:
Last Closed: 2008-05-21 14:56:33 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: 248532    
Bug Blocks: 425461    
Attachments:
Description Flags
Testcase. none

Description Jan Kratochvil 2007-09-27 18:00:19 UTC 
+++ This bug was initially created as a clone of Bug #248532 +++

Description of problem:
Behavior change from the upstream.  It affects the method I found out as the
minimal/reliable way to attach unstopped+stopped processes on upstream kernels:
http://www.jankratochvil.net/priv/ver5.txt
* kill(SIGSTOP) the child
* waitid() (waitpid()) on it to catch its SIGSTOP notification
* PTRACE_ATTACH
* tkill(SIGCONT)
* waitpid() - should not hang

Version-Release number of selected component (if applicable):
kernel-2.6.18-48.el5.x86_64

How reproducible:
Always.

Steps to Reproduce:
1. gcc -o attach-sigcont-wait attach-sigcont-wait.c -Wall -ggdb2
2. ./attach-sigcont-wait

Actual results:
Aborted
(due to a timeout on hung waitpid())

Expected results:
PASS
Comment 1 Jan Kratochvil 2007-09-27 18:00:19 UTC 
Created attachment 208791 [details]
Testcase.
Comment 3 Jan Kratochvil 2007-11-16 23:43:34 UTC 
Already fixed in the original Fedora Bug 248532.
Comment 4 Eric Bachalo 2007-12-14 20:36:47 UTC 
Roland is/will be working on this issue.
Comment 5 RHEL Program Management 2007-12-14 20:37:23 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 7 Don Zickus 2007-12-21 20:18:00 UTC 
in 2.6.18-62.el5
You can download this test kernel from http://people.redhat.com/dzickus/el5
Comment 9 Mike Gahagan 2008-01-28 21:24:55 UTC 
Confirmed attach-sigcont-wait now passes with the -75.el5 kernel
Comment 11 errata-xmlrpc 2008-05-21 14:56:33 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 the 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/RHBA-2008-0314.html