From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 26808 invoked by alias); 24 Nov 2009 17:27:58 -0000 Received: (qmail 26799 invoked by uid 22791); 24 Nov 2009 17:27:57 -0000 X-SWARE-Spam-Status: No, hits=-1.0 required=5.0 tests=AWL,BAYES_00,SPF_PASS X-Spam-Check-By: sourceware.org Received: from mail-in-10.arcor-online.net (HELO mail-in-10.arcor-online.net) (151.189.21.50) by sourceware.org (qpsmtpd/0.43rc1) with ESMTP; Tue, 24 Nov 2009 17:27:51 +0000 Received: from mail-in-13-z2.arcor-online.net (mail-in-13-z2.arcor-online.net [151.189.8.30]) by mx.arcor.de (Postfix) with ESMTP id 54B9528EFD6 for ; Tue, 24 Nov 2009 18:27:48 +0100 (CET) Received: from mail-in-11.arcor-online.net (mail-in-11.arcor-online.net [151.189.21.51]) by mail-in-13-z2.arcor-online.net (Postfix) with ESMTP id 38FCE1B8E06 for ; Tue, 24 Nov 2009 18:27:48 +0100 (CET) Received: from webmail08.arcor-online.net (webmail08.arcor-online.net [151.189.8.44]) by mail-in-11.arcor-online.net (Postfix) with ESMTP id CFF02E39A1 for ; Tue, 24 Nov 2009 18:27:47 +0100 (CET) X-DKIM: Sendmail DKIM Filter v2.8.2 mail-in-11.arcor-online.net CFF02E39A1 Received: from [193.158.31.250] by webmail08.arcor-online.net (151.189.8.44) with HTTP (Arcor Webmail); Tue, 24 Nov 2009 18:27:47 +0100 (CET) Message-ID: <25069460.1259083667780.JavaMail.ngmail@webmail08.arcor-online.net> Date: Tue, 24 Nov 2009 17:27:00 -0000 From: daniel-kay@arcor.de To: systemtap@sourceware.org Subject: Dereferencing simple pointers MIME-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit X-ngMessageSubType: MessageSubType_MAIL X-WebmailclientIP: 193.158.31.250 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 X-SW-Source: 2009-q4/txt/msg00670.txt.bz2 Hello Folks, I am playing around with systemtap and am quite impressed. But there is one thing that confuses me. Is there any way that I can derefernce a single pointer from a function parameter inside a probe? Example: # Function from current Kernel (drivers/char/random.c:1049): urandom_read(struct file *file, char __user *buf, size_t nbytes, loff_t *ppos) { return extract_entropy_user(&nonblocking_pool, buf, nbytes); } # My Probe Attempt without success: probe kernel.function("urandom_read") { printf("%s\n", *($ppos)); } I can't believe that this isn't possible... Thanks in advance, Daniel Kay