From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 9120 invoked by alias); 17 Oct 2013 18:51:23 -0000 Mailing-List: contact systemtap-help@sourceware.org; run by ezmlm Precedence: bulk List-Id: List-Subscribe: List-Post: List-Help: , Sender: systemtap-owner@sourceware.org Received: (qmail 9086 invoked by uid 48); 17 Oct 2013 18:51:20 -0000 From: "dsmith at redhat dot com" To: systemtap@sourceware.org Subject: [Bug tapsets/15913] on s390x, nd_syscall.execve fails when accessing filename Date: Thu, 17 Oct 2013 18:51:00 -0000 X-Bugzilla-Reason: AssignedTo X-Bugzilla-Type: changed X-Bugzilla-Watch-Reason: None X-Bugzilla-Product: systemtap X-Bugzilla-Component: tapsets X-Bugzilla-Version: unspecified X-Bugzilla-Keywords: X-Bugzilla-Severity: normal X-Bugzilla-Who: dsmith at redhat dot com X-Bugzilla-Status: RESOLVED X-Bugzilla-Priority: P2 X-Bugzilla-Assigned-To: systemtap at sourceware dot org X-Bugzilla-Target-Milestone: --- X-Bugzilla-Flags: X-Bugzilla-Changed-Fields: bug_status resolution Message-ID: In-Reply-To: References: Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit X-Bugzilla-URL: http://sourceware.org/bugzilla/ Auto-Submitted: auto-generated MIME-Version: 1.0 X-SW-Source: 2013-q4/txt/msg00057.txt.bz2 https://sourceware.org/bugzilla/show_bug.cgi?id=15913 David Smith changed: What |Removed |Added ---------------------------------------------------------------------------- Status|REOPENED |RESOLVED Resolution|--- |FIXED --- Comment #3 from David Smith --- After some discussion with the kernel folks, this is a systemtap problem. Bug #11763 tried to fix accessing argument 6 on the s390x by using the kernel's syscall_get_arguments(). However, that function is only guaranteed to work on the pt_regs structure that gets intialized when a context switch from user space to kernel space happens due to a system call. This pt_regs structure is returned by 'task_pt_regs(current)'. But, when using int_arg(N) in the nd_syscall tapset, we don't want the syscall's arg N, we want the *current* kernel function's arg N (since the function we're probing could be several calls away from the actual system call). So, after some investigation, I've rewritten the s390x _stp_get_arg() to handle getting argument 6 (and above) from the stack. I've tested this on RHEL5, RHEL6, and more recent kernels (3.10). Fixed in commit eefd579. -- You are receiving this mail because: You are the assignee for the bug.