public inbox for systemtap@sourceware.org
 help / color / mirror / Atom feed
From: "mjw at redhat dot com" <sourceware-bugzilla@sourceware.org>
To: systemtap@sourceware.org
Subject: [Bug runtime/13467] New: user array indexing pointer_array.exp testcase fails on s390x needs @user($ptr)
Date: Fri, 02 Dec 2011 19:36:00 -0000	[thread overview]
Message-ID: <bug-13467-6586@http.sourceware.org/bugzilla/> (raw)

http://sourceware.org/bugzilla/show_bug.cgi?id=13467

             Bug #: 13467
           Summary: user array indexing pointer_array.exp testcase fails
                    on s390x needs @user($ptr)
           Product: systemtap
           Version: unspecified
            Status: NEW
          Severity: normal
          Priority: P2
         Component: runtime
        AssignedTo: systemtap@sourceware.org
        ReportedBy: mjw@redhat.com
    Classification: Unclassified


pointer_array.stp basically does:

probe syscall.execve { println(user_string($argv[0])) }

The $argv[0] is evaluated in kernel context, but is really a user pointer.
So you will get a ERROR: kernel read fault at 0x00000000859fa100 (addr) near
identifier '$argv'.

The following would "fix" it:

probe syscall.execve { println(user_string(user_long($argv))) }

But the test really is about array indexing. The next tests try to extract the
individual chars with $argv[0][1], etc.

We could rewrite the testcase to use a user array in a user probe context.
But maybe we need some kind of @user($ptr) construct, which would then give you
an object that can be evaluated through []/-> as if in a user probe context?

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

                 reply	other threads:[~2011-12-02 16:15 UTC|newest]

Thread overview: [no followups] expand[flat|nested]  mbox.gz  Atom feed

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=bug-13467-6586@http.sourceware.org/bugzilla/ \
    --to=sourceware-bugzilla@sourceware.org \
    --cc=systemtap@sourceware.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).