From nobody Wed Dec 17 16:54:37 2025 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 20966C77B7C for ; Tue, 18 Apr 2023 21:28:50 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233013AbjDRV2t (ORCPT ); Tue, 18 Apr 2023 17:28:49 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:45714 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232999AbjDRV2e (ORCPT ); Tue, 18 Apr 2023 17:28:34 -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 D0C12CC0B for ; Tue, 18 Apr 2023 14:28:13 -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 D12D96395F for ; Tue, 18 Apr 2023 21:28:02 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 1075AC4339E; Tue, 18 Apr 2023 21:28:02 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1681853282; bh=ntG9ViCrjPSzd67qUu5eqOdkFLpY/tylKZuYgUZ9cSU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=pk0raLmseMDt9vaVephe1yLCLi62LKnBpUmBkCmZlO4/Sn3u7b5Ln3Zq5YmxpVl+4 /t87PR/8MhAMcKqkGZLxm4l1AzGlZAYMNnGoWU97LqXABy7V+oyb7fV2BX5mefj5v9 ZgONh0VS3+sWtvi9PqpNzfztuVF2fvJhT93yBfdsF6NUXBndZ4JFT2xAQj9F9lsBcD Ofa4D3QKqOVN02bDfDOTunZixBiISy78Mo4Lczhwm6GMndgpBvRj/QQviAUl1ckPXc fEoFqkIPx6TAG28sjHwumFEAsFUNVPf8iv/Ywge5y5uV0EGzIkDfuyalEG+UYb/MOf e2KbhGMX43y9Q== From: Josh Poimboeuf To: x86@kernel.org Cc: linux-kernel@vger.kernel.org, Peter Zijlstra , Miroslav Benes , Nick Desaulniers Subject: [PATCH v3 8/8] objtool: Move noreturn function list to separate file Date: Tue, 18 Apr 2023 14:27:54 -0700 Message-Id: X-Mailer: git-send-email 2.39.2 In-Reply-To: References: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" This makes it a little cleaner and easier to maintain. Suggested-by: Peter Zijlstra Signed-off-by: Josh Poimboeuf --- tools/objtool/Documentation/objtool.txt | 5 ++- tools/objtool/check.c | 44 ++---------------------- tools/objtool/noreturns.h | 45 +++++++++++++++++++++++++ 3 files changed, 50 insertions(+), 44 deletions(-) create mode 100644 tools/objtool/noreturns.h diff --git a/tools/objtool/Documentation/objtool.txt b/tools/objtool/Docume= ntation/objtool.txt index 2cd1fa16ed08..00f0a7e385ec 100644 --- a/tools/objtool/Documentation/objtool.txt +++ b/tools/objtool/Documentation/objtool.txt @@ -306,9 +306,8 @@ the objtool maintainers. 3. file.o: warning: objtool: foo+0x48c: bar() is missing a __noreturn anno= tation =20 The call from foo() to bar() doesn't return, but bar() is missing the - __noreturn annotation. NOTE: In addition to adding the __noreturn - annotation, the function name also needs to be added to - 'global_noreturns' in tools/objtool/check.c. + __noreturn annotation. NOTE: In addition to annotating the function + with __noreturn, please also add it to tools/objtool/noreturns.h. =20 4. file.o: warning: objtool: func(): can't find starting instruction or diff --git a/tools/objtool/check.c b/tools/objtool/check.c index 2047a6d5339b..69794c25f857 100644 --- a/tools/objtool/check.c +++ b/tools/objtool/check.c @@ -192,49 +192,11 @@ static bool __dead_end_function(struct objtool_file *= file, struct symbol *func, struct instruction *insn; bool empty =3D true; =20 - /* - * Unfortunately these have to be hard coded because the noreturn - * attribute isn't provided in ELF data. Keep 'em sorted. - */ +#define NORETURN(func) __stringify(func), static const char * const global_noreturns[] =3D { - "__invalid_creds", - "__module_put_and_kthread_exit", - "__reiserfs_panic", - "__stack_chk_fail", - "__ubsan_handle_builtin_unreachable", - "arch_call_rest_init", - "arch_cpu_idle_dead", - "btrfs_assertfail", - "cpu_bringup_and_idle", - "cpu_startup_entry", - "do_exit", - "do_group_exit", - "do_task_dead", - "ex_handler_msr_mce", - "fortify_panic", - "hlt_play_dead", - "hv_ghcb_terminate", - "kthread_complete_and_exit", - "kthread_exit", - "kunit_try_catch_throw", - "machine_real_restart", - "make_task_dead", - "mpt_halt_firmware", - "nmi_panic_self_stop", - "panic", - "panic_smp_self_stop", - "rest_init", - "rewind_stack_and_make_dead", - "sev_es_terminate", - "snp_abort", - "start_kernel", - "stop_this_cpu", - "usercopy_abort", - "x86_64_start_kernel", - "x86_64_start_reservations", - "xen_cpu_bringup_again", - "xen_start_kernel", +#include "noreturns.h" }; +#undef NORETURN =20 if (!func) return false; diff --git a/tools/objtool/noreturns.h b/tools/objtool/noreturns.h new file mode 100644 index 000000000000..cede6068ddf6 --- /dev/null +++ b/tools/objtool/noreturns.h @@ -0,0 +1,45 @@ +/* SPDX-License-Identifier: GPL-2.0 */ + +/* + * This is a (sorted!) list of all known __noreturn functions in the kerne= l. + * It's needed for objtool to properly reverse-engineer the control flow g= raph. + * + * Yes, this is unfortunate. A better solution is in the works. + */ +NORETURN(__invalid_creds) +NORETURN(__module_put_and_kthread_exit) +NORETURN(__reiserfs_panic) +NORETURN(__stack_chk_fail) +NORETURN(__ubsan_handle_builtin_unreachable) +NORETURN(arch_call_rest_init) +NORETURN(arch_cpu_idle_dead) +NORETURN(btrfs_assertfail) +NORETURN(cpu_bringup_and_idle) +NORETURN(cpu_startup_entry) +NORETURN(do_exit) +NORETURN(do_group_exit) +NORETURN(do_task_dead) +NORETURN(ex_handler_msr_mce) +NORETURN(fortify_panic) +NORETURN(hlt_play_dead) +NORETURN(hv_ghcb_terminate) +NORETURN(kthread_complete_and_exit) +NORETURN(kthread_exit) +NORETURN(kunit_try_catch_throw) +NORETURN(machine_real_restart) +NORETURN(make_task_dead) +NORETURN(mpt_halt_firmware) +NORETURN(nmi_panic_self_stop) +NORETURN(panic) +NORETURN(panic_smp_self_stop) +NORETURN(rest_init) +NORETURN(rewind_stack_and_make_dead) +NORETURN(sev_es_terminate) +NORETURN(snp_abort) +NORETURN(start_kernel) +NORETURN(stop_this_cpu) +NORETURN(usercopy_abort) +NORETURN(x86_64_start_kernel) +NORETURN(x86_64_start_reservations) +NORETURN(xen_cpu_bringup_again) +NORETURN(xen_start_kernel) --=20 2.39.2