From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-10.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id AA0D4C43387 for ; Fri, 18 Jan 2019 04:44:51 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 791302087E for ; Fri, 18 Jan 2019 04:44:51 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1547786691; bh=mw3nME0qApRJLMHYDdox9GFSvvlegsr6Kb6TUq7uNjM=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=vVBI6aM3kTLbx+r8Dw7rfjGpim0jpCnkQcYEP2GnLS1H3XNSd9Nr687WkEQY+s+wC PzKPwTO6XL2uT13MRG7UvqdjgU9ybbwCnKfXKTwnwIveed9gMD4PJF7YVUNJnOrcgQ r6Vl20nZMT/9ulJuf/ngz0IS0dOmwBEsR51lAxFA= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727192AbfAREot (ORCPT ); Thu, 17 Jan 2019 23:44:49 -0500 Received: from mail.kernel.org ([198.145.29.99]:56462 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726989AbfAREot (ORCPT ); Thu, 17 Jan 2019 23:44:49 -0500 Received: from localhost.localdomain (NE2965lan1.rev.em-net.ne.jp [210.141.244.193]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id B999D2086D; Fri, 18 Jan 2019 04:44:47 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1547786688; bh=mw3nME0qApRJLMHYDdox9GFSvvlegsr6Kb6TUq7uNjM=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=RCDQLy6yHuEveEOaHoZgA3zqW+EN5xKJjqRy4XzLIrRw02qd2Z8PDqgtUxcCV+q0T +Nu7Ze08vz4gnrCiBYOMPtoIwZzhCw0IZG5jJ0TasXXZlfLE5EtfuKwZ2Tu0O4DmSK vWJGC2F0Qd6wJKKRlYJCR2uUedJvrMAiRtY1P86c= From: Masami Hiramatsu To: Steven Rostedt Cc: Andreas Ziegler , Masami Hiramatsu , Ingo Molnar , linux-kernel@vger.kernel.org Subject: [PATCH v2 1/3] tracing: uprobes: Re-enable $comm support for uprobe events Date: Fri, 18 Jan 2019 13:44:25 +0900 Message-Id: <154778666570.19927.5960654930869453736.stgit@devbox> X-Mailer: git-send-email 2.13.6 In-Reply-To: <154778663676.19927.12774448308165809570.stgit@devbox> References: <154778663676.19927.12774448308165809570.stgit@devbox> User-Agent: StGit/0.17.1-dirty MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Since commit 533059281ee5 ("tracing: probeevent: Introduce new argument fetching code") dropped the $comm support from uprobe events, this re-enables it. For $comm support, uses strlcpy() instead of strncpy_from_user() to copy current task's comm. Because it is in the kernel space, strncpy_from_user() always fails to copy the comm. This also uses strlen() instead of strnlen_user() to measure the length of the comm. Fixes: 533059281ee5 ("tracing: probeevent: Introduce new argument fetching code") Signed-off-by: Masami Hiramatsu Reported-by: Andreas Ziegler Acked-by: Andreas Ziegler --- kernel/trace/trace_uprobe.c | 15 +++++++++++++-- 1 file changed, 13 insertions(+), 2 deletions(-) diff --git a/kernel/trace/trace_uprobe.c b/kernel/trace/trace_uprobe.c index 3a1d5ab6b4ba..b07e498ccbc6 100644 --- a/kernel/trace/trace_uprobe.c +++ b/kernel/trace/trace_uprobe.c @@ -156,7 +156,10 @@ fetch_store_string(unsigned long addr, void *dest, void *base) if (unlikely(!maxlen)) return -ENOMEM; - ret = strncpy_from_user(dst, src, maxlen); + if (addr == (unsigned long)current->comm) + ret = strlcpy(dst, current->comm, maxlen); + else + ret = strncpy_from_user(dst, src, maxlen); if (ret >= 0) { if (ret == maxlen) dst[ret - 1] = '\0'; @@ -180,7 +183,12 @@ fetch_store_strlen(unsigned long addr) int len; void __user *vaddr = (void __force __user *) addr; - len = strnlen_user(vaddr, MAX_STRING_SIZE); + if (addr == (unsigned long)current->comm) { + len = strlen(current->comm); + if (len) + len++; + } else + len = strnlen_user(vaddr, MAX_STRING_SIZE); return (len > MAX_STRING_SIZE) ? 0 : len; } @@ -220,6 +228,9 @@ process_fetch_insn(struct fetch_insn *code, struct pt_regs *regs, void *dest, case FETCH_OP_IMM: val = code->immediate; break; + case FETCH_OP_COMM: + val = (unsigned long)current->comm; + break; case FETCH_OP_FOFFS: val = translate_user_vaddr(code->immediate); break;