User probes on ppc64le are not returning the correct values of the probed function's arguments.
Affects | Status | Importance | Assigned to | Milestone | |
---|---|---|---|---|---|
systemtap (Ubuntu) |
New
|
Undecided
|
Unassigned |
Bug Description
== Comment: #0 - David J. Wilder <email address hidden> - 2015-07-15 19:51:49 ==
---Problem Description---
User probes on ppc64le are not returning the correct values of the probed function's arguments.
Contact Information = <email address hidden>
---uname output---
Linux Daves-sandbox 3.19.0-21-generic #21-Ubuntu SMP Sun Jun 14 19:33:37 UTC 2015 ppc64le ppc64le ppc64le GNU/Linux
Machine Type = 8284-22A (power8, running on a VM on top of powerKVM)
---Debugger---
A debugger is not configured
---Steps to Reproduce---
$ cat doit.c
#include <stdio.h>
doit( int i )
{
printf("%s: i=%d\n"
pause();
}
main()
{
doit(42);
}
$ cat doit.stp
probe process(
printf("function doit called with i=%ld\n",$i);
}
$ gcc -g -o doit doit.c
$ sudo stap doit.stp -c ./doit
doit: i=42
function doit called with i=16383 <<<< I expect 42
---------
If I run the same example on a x86-64 system I get the expected results. So I think this is a problem with ppc64 only.
$ uname -a
Linux ubuntu-15 3.19.0-15-generic #15-Ubuntu SMP Thu Apr 16 23:32:37 UTC 2015 x86_64 x86_64 x86_64 GNU/Linux
$ sudo stap doit.stp -c ./doit
doit: i=42
function doit called with i=42
Other information (from ppc64le system):
I build systemtap from upstream git. The version Canonical is shipping is broken.
$ stap --version
Systemtap translator/driver (version 2.9/0.160, commit release-
Copyright (C) 2005-2015 Red Hat, Inc. and others
This is free software; see the source for copying conditions.
enabled features: TR1_UNORDERED_MAP NLS
$ grep CONFIG_UPROBES /boot/config-`uname -r`
CONFIG_UPROBES=y
------
Userspace tool common name: stap
The userspace tool has the following bit modes: 64-bit
Userspace rpm: systemtap
Userspace tool obtained from project website: na
*Additional Instructions for <email address hidden>:
-Post a private note with access information to the machine that the bug is occuring on.
-Attach ltrace and strace of userspace application.
Please cherry pick the fix.
https:/
https:/
tags: | added: architecture-ppc64le bugnameltc-127718 severity-medium targetmilestone-inin1704 |
Changed in ubuntu: | |
assignee: | nobody → Taco Screen team (taco-screen-team) |
affects: | ubuntu → systemtap (Ubuntu) |
tags: | removed: bugnameltc-127718 severity-medium |
tags: | added: bugnameltc-127718 severity-medium |
Systemtap is in universe and is community supported. Removing Taco Screen team.