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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 00E55C433FE for ; Mon, 21 Mar 2022 13:55:51 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1348216AbiCUN5O (ORCPT ); Mon, 21 Mar 2022 09:57:14 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:44980 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1348315AbiCUN4L (ORCPT ); Mon, 21 Mar 2022 09:56:11 -0400 Received: from ams.source.kernel.org (ams.source.kernel.org [145.40.68.75]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id A5945366A9; Mon, 21 Mar 2022 06:54:33 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id 30339B81598; Mon, 21 Mar 2022 13:54:32 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 6E191C340E8; Mon, 21 Mar 2022 13:54:30 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1647870870; bh=gSfgLPapIDKi4AvNo7RkyNdwPynnYRvGBh1tgWpe270=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=kGl/uUWl9UtZEKA4Vdl/twX7E4/SvTId2qX3NvIz97/Yp1rQ+qfo9iB1YOaslq2kn INJGQzm4hEz3+yhIg4yocTdoyXsUTvO4PNzXrbVwZ/zHDDkURtYSJ0CnNGgXYPHmf1 Yyq03wQIxXCqqdCY+7KR7NM3bfME6VXbJk/oAsg4= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Michael Petlan , Athira Jajeev , Jiri Olsa , Kajol Jain , Madhavan Srinivasan , Arnaldo Carvalho de Melo Subject: [PATCH 4.14 22/22] perf symbols: Fix symbol size calculation condition Date: Mon, 21 Mar 2022 14:51:53 +0100 Message-Id: <20220321133218.258881747@linuxfoundation.org> X-Mailer: git-send-email 2.35.1 In-Reply-To: <20220321133217.602054917@linuxfoundation.org> References: <20220321133217.602054917@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Michael Petlan commit 3cf6a32f3f2a45944dd5be5c6ac4deb46bcd3bee upstream. Before this patch, the symbol end address fixup to be called, needed two conditions being met: if (prev->end == prev->start && prev->end != curr->start) Where "prev->end == prev->start" means that prev is zero-long (and thus needs a fixup) and "prev->end != curr->start" means that fixup hasn't been applied yet However, this logic is incorrect in the following situation: *curr = {rb_node = {__rb_parent_color = 278218928, rb_right = 0x0, rb_left = 0x0}, start = 0xc000000000062354, end = 0xc000000000062354, namelen = 40, type = 2 '\002', binding = 0 '\000', idle = 0 '\000', ignore = 0 '\000', inlined = 0 '\000', arch_sym = 0 '\000', annotate2 = false, name = 0x1159739e "kprobe_optinsn_page\t[__builtin__kprobes]"} *prev = {rb_node = {__rb_parent_color = 278219041, rb_right = 0x109548b0, rb_left = 0x109547c0}, start = 0xc000000000062354, end = 0xc000000000062354, namelen = 12, type = 2 '\002', binding = 1 '\001', idle = 0 '\000', ignore = 0 '\000', inlined = 0 '\000', arch_sym = 0 '\000', annotate2 = false, name = 0x1095486e "optinsn_slot"} In this case, prev->start == prev->end == curr->start == curr->end, thus the condition above thinks that "we need a fixup due to zero length of prev symbol, but it has been probably done, since the prev->end == curr->start", which is wrong. After the patch, the execution path proceeds to arch__symbols__fixup_end function which fixes up the size of prev symbol by adding page_size to its end offset. Fixes: 3b01a413c196c910 ("perf symbols: Improve kallsyms symbol end addr calculation") Signed-off-by: Michael Petlan Cc: Athira Jajeev Cc: Jiri Olsa Cc: Kajol Jain Cc: Madhavan Srinivasan Link: http://lore.kernel.org/lkml/20220317135536.805-1-mpetlan@redhat.com Signed-off-by: Arnaldo Carvalho de Melo Signed-off-by: Greg Kroah-Hartman --- tools/perf/util/symbol.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/tools/perf/util/symbol.c +++ b/tools/perf/util/symbol.c @@ -224,7 +224,7 @@ void symbols__fixup_end(struct rb_root * prev = curr; curr = rb_entry(nd, struct symbol, rb_node); - if (prev->end == prev->start && prev->end != curr->start) + if (prev->end == prev->start || prev->end != curr->start) arch__symbols__fixup_end(prev, curr); }