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 9E800C43334 for ; Mon, 20 Jun 2022 14:02:06 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S241574AbiFTOCC (ORCPT ); Mon, 20 Jun 2022 10:02:02 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:44182 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1351873AbiFTNzf (ORCPT ); Mon, 20 Jun 2022 09:55:35 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 70BD5344F2; Mon, 20 Jun 2022 06:21:42 -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 dfw.source.kernel.org (Postfix) with ESMTPS id DE01A60FF3; Mon, 20 Jun 2022 13:21:39 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id D1747C341C5; Mon, 20 Jun 2022 13:21:38 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1655731299; bh=ytZ1+hFyV2RqybENQgs4g/BucLFJXxFLio4+veEmxzc=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=KOHp0NJYFhbjaHZAEJyIGQDQ1c13v0+AUXGErPd8Ajo6lFUol4rBIQu2pt+Ey0F1l wjovJDgCzsMat7lK43cxcKOwrIPbate8hhk8IGPu/IH5YDpc812xjUKY9Mehs1zRtq ULsJryZ2L0ngtMOLm2kLE5wvXgURGFNqNZ8cf9Cc= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Peter Zijlstra , Josh Poimboeuf , Sasha Levin Subject: [PATCH 5.4 216/240] faddr2line: Fix overlapping text section failures, the sequel Date: Mon, 20 Jun 2022 14:51:57 +0200 Message-Id: <20220620124745.230302229@linuxfoundation.org> X-Mailer: git-send-email 2.36.1 In-Reply-To: <20220620124737.799371052@linuxfoundation.org> References: <20220620124737.799371052@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: stable@vger.kernel.org From: Josh Poimboeuf [ Upstream commit dcea997beed694cbd8705100ca1a6eb0d886de69 ] If a function lives in a section other than .text, but .text also exists in the object, faddr2line may wrongly assume .text. This can result in comically wrong output. For example: $ scripts/faddr2line vmlinux.o enter_from_user_mode+0x1c enter_from_user_mode+0x1c/0x30: find_next_bit at /home/jpoimboe/git/linux/./include/linux/find.h:40 (inlined by) perf_clear_dirty_counters at /home/jpoimboe/git/linux/arch/x86/events/core.c:2504 Fix it by passing the section name to addr2line, unless the object file is vmlinux, in which case the symbol table uses absolute addresses. Fixes: 1d1a0e7c5100 ("scripts/faddr2line: Fix overlapping text section failures") Reported-by: Peter Zijlstra Signed-off-by: Josh Poimboeuf Link: https://lore.kernel.org/r/7d25bc1408bd3a750ac26e60d2f2815a5f4a8363.1654130536.git.jpoimboe@kernel.org Signed-off-by: Sasha Levin --- scripts/faddr2line | 45 ++++++++++++++++++++++++++++++++++----------- 1 file changed, 34 insertions(+), 11 deletions(-) diff --git a/scripts/faddr2line b/scripts/faddr2line index 0e6268d59883..94ed98dd899f 100755 --- a/scripts/faddr2line +++ b/scripts/faddr2line @@ -95,17 +95,25 @@ __faddr2line() { local print_warnings=$4 local sym_name=${func_addr%+*} - local offset=${func_addr#*+} - offset=${offset%/*} + local func_offset=${func_addr#*+} + func_offset=${func_offset%/*} local user_size= + local file_type + local is_vmlinux=0 [[ $func_addr =~ "/" ]] && user_size=${func_addr#*/} - if [[ -z $sym_name ]] || [[ -z $offset ]] || [[ $sym_name = $func_addr ]]; then + if [[ -z $sym_name ]] || [[ -z $func_offset ]] || [[ $sym_name = $func_addr ]]; then warn "bad func+offset $func_addr" DONE=1 return fi + # vmlinux uses absolute addresses in the section table rather than + # section offsets. + local file_type=$(${READELF} --file-header $objfile | + ${AWK} '$1 == "Type:" { print $2; exit }') + [[ $file_type = "EXEC" ]] && is_vmlinux=1 + # Go through each of the object's symbols which match the func name. # In rare cases there might be duplicates, in which case we print all # matches. @@ -114,9 +122,11 @@ __faddr2line() { local sym_addr=0x${fields[1]} local sym_elf_size=${fields[2]} local sym_sec=${fields[6]} + local sec_size + local sec_name # Get the section size: - local sec_size=$(${READELF} --section-headers --wide $objfile | + sec_size=$(${READELF} --section-headers --wide $objfile | sed 's/\[ /\[/' | ${AWK} -v sec=$sym_sec '$1 == "[" sec "]" { print "0x" $6; exit }') @@ -126,6 +136,17 @@ __faddr2line() { return fi + # Get the section name: + sec_name=$(${READELF} --section-headers --wide $objfile | + sed 's/\[ /\[/' | + ${AWK} -v sec=$sym_sec '$1 == "[" sec "]" { print $2; exit }') + + if [[ -z $sec_name ]]; then + warn "bad section name: section: $sym_sec" + DONE=1 + return + fi + # Calculate the symbol size. # # Unfortunately we can't use the ELF size, because kallsyms @@ -174,10 +195,10 @@ __faddr2line() { sym_size=0x$(printf %x $sym_size) - # Calculate the section address from user-supplied offset: - local addr=$(($sym_addr + $offset)) + # Calculate the address from user-supplied offset: + local addr=$(($sym_addr + $func_offset)) if [[ -z $addr ]] || [[ $addr = 0 ]]; then - warn "bad address: $sym_addr + $offset" + warn "bad address: $sym_addr + $func_offset" DONE=1 return fi @@ -191,9 +212,9 @@ __faddr2line() { fi # Make sure the provided offset is within the symbol's range: - if [[ $offset -gt $sym_size ]]; then + if [[ $func_offset -gt $sym_size ]]; then [[ $print_warnings = 1 ]] && - echo "skipping $sym_name address at $addr due to size mismatch ($offset > $sym_size)" + echo "skipping $sym_name address at $addr due to size mismatch ($func_offset > $sym_size)" continue fi @@ -202,11 +223,13 @@ __faddr2line() { [[ $FIRST = 0 ]] && echo FIRST=0 - echo "$sym_name+$offset/$sym_size:" + echo "$sym_name+$func_offset/$sym_size:" # Pass section address to addr2line and strip absolute paths # from the output: - local output=$(${ADDR2LINE} -fpie $objfile $addr | sed "s; $dir_prefix\(\./\)*; ;") + local args="--functions --pretty-print --inlines --exe=$objfile" + [[ $is_vmlinux = 0 ]] && args="$args --section=$sec_name" + local output=$(${ADDR2LINE} $args $addr | sed "s; $dir_prefix\(\./\)*; ;") [[ -z $output ]] && continue # Default output (non --list): -- 2.35.1