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 D334BC77B7D for ; Thu, 18 May 2023 11:09:23 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231196AbjERLJV (ORCPT ); Thu, 18 May 2023 07:09:21 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:43538 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231179AbjERLJP (ORCPT ); Thu, 18 May 2023 07:09:15 -0400 Received: from galois.linutronix.de (Galois.linutronix.de [193.142.43.55]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id AD8BF2134; Thu, 18 May 2023 04:08:34 -0700 (PDT) Date: Thu, 18 May 2023 11:08:02 -0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1684408083; h=from:from:sender:sender:reply-to:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=4l2NYHmbJ9RLaYs6c6lgF3CKWCorQeRK5kkXH/k0WVA=; b=CZl8PdzbETXyq4DgVVb+dbWxsrmTi2JVR+zUXijPn3ndaR7B4vWBKOEyaQ5XF8y9/qhOIy 1wUSpHU+wZdacqebipQHpy6G6NbUvRfTV7UXSgTXNMfP0KiMpSFokciPQ8c+SnrMLumsK9 zOfp8d4ETA74JbtpQKcDLAL6Xk03zZfHGfNLL5CxUz2rWDaPd1+6e5pfkvEAfSEh/AXs8V 87aR2sIdXWxlfAwX0hKMSH8ZW/0U4T7BpHNGCMPJ2k3us1XjLtzh+lhAXXuBDkSuAoBmlk Ni6rSSLXMlbj9KgLwh5bI/N3Rlzk7NwnJGCTmcIIVqx26/WBawu9FHsuVBTonQ== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1684408083; h=from:from:sender:sender:reply-to:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=4l2NYHmbJ9RLaYs6c6lgF3CKWCorQeRK5kkXH/k0WVA=; b=OUVSZqpI7DmB5YP/CtRxNe5fGDqwXLmq/ps+1RaOsBG7NmtLQmUK2zqbBF0Kj2jKlzf3AL NiXGhYXcIXcz5mDw== From: "tip-bot2 for Josh Poimboeuf" Sender: tip-bot2@linutronix.de Reply-to: linux-kernel@vger.kernel.org To: linux-tip-commits@vger.kernel.org Subject: [tip: objtool/core] objtool: Add verbose option for disassembling affected functions Cc: Miroslav Benes , Josh Poimboeuf , x86@kernel.org, linux-kernel@vger.kernel.org In-Reply-To: References: MIME-Version: 1.0 Message-ID: <168440808274.404.5668260031593336858.tip-bot2@tip-bot2> Robot-ID: Robot-Unsubscribe: Contact to get blacklisted from these emails Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The following commit has been merged into the objtool/core branch of tip: Commit-ID: ca653464dd097fe64e69f1735e9f348b2a0f8037 Gitweb: https://git.kernel.org/tip/ca653464dd097fe64e69f1735e9f348b2a0f8037 Author: Josh Poimboeuf AuthorDate: Tue, 18 Apr 2023 14:27:48 -07:00 Committer: Josh Poimboeuf CommitterDate: Tue, 16 May 2023 06:31:51 -07:00 objtool: Add verbose option for disassembling affected functions When a warning is associated with a function, add an option to disassemble that function. This makes it easier for reporters to submit the information needed to diagnose objtool warnings. Reviewed-by: Miroslav Benes Link: https://lore.kernel.org/r/dd0fe13428ede186f09c74059a8001f4adcea5fc.1681853186.git.jpoimboe@kernel.org Signed-off-by: Josh Poimboeuf --- tools/objtool/Documentation/objtool.txt | 5 ++- tools/objtool/builtin-check.c | 5 ++- tools/objtool/check.c | 77 ++++++++++++++++++++++++- tools/objtool/include/objtool/builtin.h | 1 +- 4 files changed, 88 insertions(+) diff --git a/tools/objtool/Documentation/objtool.txt b/tools/objtool/Documentation/objtool.txt index 744db42..8db1f29 100644 --- a/tools/objtool/Documentation/objtool.txt +++ b/tools/objtool/Documentation/objtool.txt @@ -244,6 +244,11 @@ To achieve the validation, objtool enforces the following rules: Objtool warnings ---------------- +NOTE: When requesting help with an objtool warning, please recreate with +OBJTOOL_VERBOSE=1 (e.g., "make OBJTOOL_VERBOSE=1") and send the full +output, including any disassembly below the warning, to the objtool +maintainers. + For asm files, if you're getting an error which doesn't make sense, first make sure that the affected code follows the above rules. diff --git a/tools/objtool/builtin-check.c b/tools/objtool/builtin-check.c index 7c17519..5e21cfb 100644 --- a/tools/objtool/builtin-check.c +++ b/tools/objtool/builtin-check.c @@ -93,6 +93,7 @@ static const struct option check_options[] = { OPT_BOOLEAN(0, "no-unreachable", &opts.no_unreachable, "skip 'unreachable instruction' warnings"), OPT_BOOLEAN(0, "sec-address", &opts.sec_address, "print section addresses in warnings"), OPT_BOOLEAN(0, "stats", &opts.stats, "print statistics"), + OPT_BOOLEAN('v', "verbose", &opts.verbose, "verbose warnings"), OPT_END(), }; @@ -118,6 +119,10 @@ int cmd_parse_options(int argc, const char **argv, const char * const usage[]) parse_options(envc, envv, check_options, env_usage, 0); } + env = getenv("OBJTOOL_VERBOSE"); + if (env && !strcmp(env, "1")) + opts.verbose = true; + argc = parse_options(argc, argv, check_options, usage, 0); if (argc != 1) usage_with_options(usage, check_options); diff --git a/tools/objtool/check.c b/tools/objtool/check.c index 98e6c3b..0bd0ca4 100644 --- a/tools/objtool/check.c +++ b/tools/objtool/check.c @@ -4530,6 +4530,81 @@ static int validate_reachable_instructions(struct objtool_file *file) return warnings; } +/* 'funcs' is a space-separated list of function names */ +static int disas_funcs(const char *funcs) +{ + const char *objdump_str, *cross_compile; + int size, ret; + char *cmd; + + cross_compile = getenv("CROSS_COMPILE"); + + objdump_str = "%sobjdump -wdr %s | gawk -M -v _funcs='%s' '" + "BEGIN { split(_funcs, funcs); }" + "/^$/ { func_match = 0; }" + "/<.*>:/ { " + "f = gensub(/.*<(.*)>:/, \"\\\\1\", 1);" + "for (i in funcs) {" + "if (funcs[i] == f) {" + "func_match = 1;" + "base = strtonum(\"0x\" $1);" + "break;" + "}" + "}" + "}" + "{" + "if (func_match) {" + "addr = strtonum(\"0x\" $1);" + "printf(\"%%04x \", addr - base);" + "print;" + "}" + "}' 1>&2"; + + /* fake snprintf() to calculate the size */ + size = snprintf(NULL, 0, objdump_str, cross_compile, objname, funcs) + 1; + if (size <= 0) { + WARN("objdump string size calculation failed"); + return -1; + } + + cmd = malloc(size); + + /* real snprintf() */ + snprintf(cmd, size, objdump_str, cross_compile, objname, funcs); + ret = system(cmd); + if (ret) { + WARN("disassembly failed: %d", ret); + return -1; + } + + return 0; +} + +static int disas_warned_funcs(struct objtool_file *file) +{ + struct symbol *sym; + char *funcs = NULL, *tmp; + + for_each_sym(file, sym) { + if (sym->warned) { + if (!funcs) { + funcs = malloc(strlen(sym->name) + 1); + strcpy(funcs, sym->name); + } else { + tmp = malloc(strlen(funcs) + strlen(sym->name) + 2); + sprintf(tmp, "%s %s", funcs, sym->name); + free(funcs); + funcs = tmp; + } + } + } + + if (funcs) + disas_funcs(funcs); + + return 0; +} + int check(struct objtool_file *file) { int ret, warnings = 0; @@ -4674,6 +4749,8 @@ int check(struct objtool_file *file) warnings += ret; } + if (opts.verbose) + disas_warned_funcs(file); if (opts.stats) { printf("nr_insns_visited: %ld\n", nr_insns_visited); diff --git a/tools/objtool/include/objtool/builtin.h b/tools/objtool/include/objtool/builtin.h index 2a108e6..fcca666 100644 --- a/tools/objtool/include/objtool/builtin.h +++ b/tools/objtool/include/objtool/builtin.h @@ -37,6 +37,7 @@ struct opts { bool no_unreachable; bool sec_address; bool stats; + bool verbose; }; extern struct opts opts;