[Bug 1659185] [NEW] User probes on ppc64le are not returning the correct values of the probed function's arguments.

[bugproxy]

Public bug reported:

== Comment: #0 - David J. Wilder <wilder at us.ibm.com> - 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 = wilder at us.ibm.com 
 
---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",__func__,i);
	pause();
}

main()
{
	doit(42);
}

$ cat doit.stp
probe process("doit").function("doit") {
	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-2.8-19-ga7396f637e7c)
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 wilder at us.ibm.com: 
-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://www.sourceware.org/git/?p=systemtap.git;a=commit;h=b0cfcdb4886be5654e94cd7893a01531345e961d

https://www.sourceware.org/git/?p=systemtap.git;a=commit;h=c3d8c09c03abd4b212a24b94601a7d5a2d9b74a1

** Affects: systemtap (Ubuntu)
     Importance: Undecided
     Assignee: Taco Screen team (taco-screen-team)
         Status: New


** Tags: architecture-ppc64le bugnameltc-127718 severity-medium targetmilestone-inin1704

** Tags added: architecture-ppc64le bugnameltc-127718 severity-medium
targetmilestone-inin1704

** Changed in: ubuntu
     Assignee: (unassigned) => Taco Screen team (taco-screen-team)

** Package changed: ubuntu => systemtap (Ubuntu)

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https://bugs.launchpad.net/bugs/1659185

Title:
  User probes on ppc64le are not returning the correct values of the
  probed function's arguments.

Status in systemtap package in Ubuntu:
  New

Bug description:
  == Comment: #0 - David J. Wilder <wilder at us.ibm.com> - 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 = wilder at us.ibm.com 
   
  ---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",__func__,i);
  	pause();
  }

  main()
  {
  	doit(42);
  }

  $ cat doit.stp
  probe process("doit").function("doit") {
  	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-2.8-19-ga7396f637e7c)
  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 wilder at us.ibm.com: 
  -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://www.sourceware.org/git/?p=systemtap.git;a=commit;h=b0cfcdb4886be5654e94cd7893a01531345e961d

  https://www.sourceware.org/git/?p=systemtap.git;a=commit;h=c3d8c09c03abd4b212a24b94601a7d5a2d9b74a1

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