[Bug tapsets/13815] New: On RHEL5 (2.6.18-308.el5), the dentry.stp tapset is broken

[Bug tapsets/13815] New: On RHEL5 (2.6.18-308.el5), the dentry.stp tapset is broken

[dsmith at redhat dot com]

http://sourceware.org/bugzilla/show_bug.cgi?id=13815

             Bug #: 13815
           Summary: On RHEL5 (2.6.18-308.el5), the dentry.stp tapset is
                    broken
           Product: systemtap
           Version: unspecified
            Status: NEW
          Severity: normal
          Priority: P2
         Component: tapsets
        AssignedTo: systemtap@sourceware.org
        ReportedBy: dsmith@redhat.com
    Classification: Unclassified


On RHEL5 (2.6.18-274.17.1.el5 x86_64) the dentry tapset works correctly and the
buildok/dentry-embedded.stp test passes.

On RHEL5 (2.6.18-308.el5 x86_64), the buildok/dentry-embedded.stp test fails:

===========
# stap -vp4 ../src/testsuite/buildok/dentry-embedded.stp 
Pass 1: parsed user script and 81 library script(s) using
145620virt/22748res/2916shr kb, in 270usr/30sys/299real ms.
semantic error: type definition 'path' not found: identifier '@cast' at
/usr/local/share/systemtap/tapset/dentry.stp:134:31
        source:                 if (dentry == @cast(root, "path")->dentry &&
                                              ^
Pass 2: analyzed script: 1 probe(s), 27 function(s), 2 embed(s), 0 global(s)
using 249740virt/67032res/4504shr kb, in 900usr/350sys/1255real ms.
Pass 2: analysis failed.  Try again with another '--vp 01' option.
===========

The source in question looks like this:

                if (dentry == @cast(root, "path")->dentry &&
                    vfsmnt == @cast(root, "path")->mnt)
                        break;

Unfortunately, just adding "kernel" to the @cast() statements doesn't fix the
problem.

Also unfortunately, the definition of 'struct path' has moved from
<linux/nfs_fs.h> in RHEL5 era kernels to <linux/path.h> in current kernels.

We may have to add in a kernel version check to fix this one unless something
more clever is found.  Adding a kernel version check would look something like
this (with the correct kernel version filled in):

%( kernel_v >= "2.6.XXXX" %?
    if (dentry == @cast(root, "path")->dentry &&
        vfsmnt == @cast(root, "path")->mnt)
            break;
%:
    if (dentry == @cast(root, "path", "kernel<linux/nfs_fs.h>)->dentry &&
        vfsmnt == @cast(root, "path", "kernel<linux/nfs_fs.h>)->mnt)
            break;
%)

-- 
Configure bugmail: http://sourceware.org/bugzilla/userprefs.cgi?tab=email
------- You are receiving this mail because: -------
You are the assignee for the bug.

[Bug tapsets/13815] On RHEL5 (2.6.18-308.el5), the dentry.stp tapset is broken

[dsmith at redhat dot com]

http://sourceware.org/bugzilla/show_bug.cgi?id=13815

David Smith <dsmith at redhat dot com> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|NEW                         |RESOLVED
         Resolution|                            |FIXED

--- Comment #1 from David Smith <dsmith at redhat dot com> 2012-03-15 18:07:47 UTC ---
Fixed in commit 56ea472.

The problem wasn't really with the @cast() operator.  In the 2.6.18-308.el5
kernel, 'struct path' was renamed to 'struct vfs_path'.  (This was done to
avoid confusion because there was more than 1 'struct path'.)

To fix this, we try casting to 'struct path' first, and if that isn't there we
try 'struct vfs_path'.

-- 
Configure bugmail: http://sourceware.org/bugzilla/userprefs.cgi?tab=email
------- You are receiving this mail because: -------
You are the assignee for the bug.