Red Hat Bugzilla – Bug 309461
utrace: tkill(SIGCONT) is not reported by waitpid() under ptrace
Last modified: 2008-05-21 10:56:33 EDT
+++ 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
Created attachment 208791 [details] Testcase.
Already fixed in the original Fedora Bug 248532.
Roland is/will be working on this issue.
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.
in 2.6.18-62.el5 You can download this test kernel from http://people.redhat.com/dzickus/el5
Confirmed attach-sigcont-wait now passes with the -75.el5 kernel
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