From patchwork Sat Apr 8 00:10:04 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Josh Poimboeuf X-Patchwork-Id: 13205491 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 1CB59C77B73 for ; Sat, 8 Apr 2023 00:10:42 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230486AbjDHAKk (ORCPT ); Fri, 7 Apr 2023 20:10:40 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:60170 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230079AbjDHAK0 (ORCPT ); Fri, 7 Apr 2023 20:10:26 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id CD91412075; Fri, 7 Apr 2023 17:10:24 -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 8773665567; Sat, 8 Apr 2023 00:10:24 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 8C210C4339C; Sat, 8 Apr 2023 00:10:23 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1680912624; bh=4wzSu4ZL5pXMt0STVtv2MfvehTIjHZdMXLjpSpIERTA=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=p9adiUttP+IEdjEtk1kh4STKzQrhqcFlzpKq5pCfK6+iFq2Lv0p/u5oWdpCaMG2/X k8yI+yuayv9s+Fg18ULnRtNCzqnqGqSR01dF0oKEqGfhTYvvKs6x4H7lnahvi7gWe6 k8zUCqUT0XDMkKQbdt1bArI0n5Z1dA5roEOQlRSIwHD3Rxcseyn7/NOWqShv7v3h7B L9Zn5VB9VhRdnDA+SuEueyhx1RW9mEu0vWUXFf9PaMwH3nRTfQbF9ch1ewRZFHQsrg eW1NjgBCqsoXI1S7Oe7xl/8EDNLZS6AkFiycG65ngyPE5TVyALJVHcMTHf071BU3sE ZHX7XfMAYWqPg== From: Josh Poimboeuf To: x86@kernel.org Cc: linux-kernel@vger.kernel.org, Peter Zijlstra , Miroslav Benes , linux-btrfs@vger.kernel.org, Mark Rutland , linux-scsi@vger.kernel.org, linux-hyperv@vger.kernel.org, Arnd Bergmann , "Guilherme G . Piccoli" , Michael Kelley Subject: [PATCH 11/11] x86/hyperv: Mark hv_ghcb_terminate() as noreturn Date: Fri, 7 Apr 2023 17:10:04 -0700 Message-Id: <8d21cbcef0e08053b36da2bc0a74ff65f5dabd43.1680912057.git.jpoimboe@kernel.org> X-Mailer: git-send-email 2.39.2 In-Reply-To: References: MIME-Version: 1.0 Content-type: text/plain Precedence: bulk List-ID: X-Mailing-List: linux-btrfs@vger.kernel.org From: "Guilherme G. Piccoli" Annotate the function prototype and definition as noreturn to prevent objtool warnings like: vmlinux.o: warning: objtool: hyperv_init+0x55c: unreachable instruction Also, as per Josh's suggestion, add it to the global_noreturns list. As a comparison, an objdump output without the annotation: [...] 1b63: mov $0x1,%esi 1b68: xor %edi,%edi 1b6a: callq ffffffff8102f680 1b6f: jmpq ffffffff82f217ec # unreachable 1b74: cmpq $0xffffffffffffffff,-0x702a24(%rip) [...] Now, after adding the __noreturn to the function prototype: [...] 17df: callq ffffffff8102f6d0 17e4: test %al,%al 17e6: je ffffffff82f21bb9 [...] 1bb9: mov $0x1,%esi 1bbe: xor %edi,%edi 1bc0: callq ffffffff8102f680 1bc5: nopw %cs:0x0(%rax,%rax,1) # end of function Reported-by: Arnd Bergmann Link: https://lore.kernel.org/r/9698eff1-9680-4f0a-94de-590eaa923e94@app.fastmail.com/ Signed-off-by: Guilherme G. Piccoli Reviewed-by: Michael Kelley Link: https://lore.kernel.org/r/20230317160546.1497477-1-gpiccoli@igalia.com Signed-off-by: Josh Poimboeuf --- arch/x86/hyperv/ivm.c | 2 +- arch/x86/include/asm/mshyperv.h | 2 +- tools/objtool/check.c | 1 + 3 files changed, 3 insertions(+), 2 deletions(-) diff --git a/arch/x86/hyperv/ivm.c b/arch/x86/hyperv/ivm.c index 1dbcbd9da74d..4f79dc76042d 100644 --- a/arch/x86/hyperv/ivm.c +++ b/arch/x86/hyperv/ivm.c @@ -127,7 +127,7 @@ static enum es_result hv_ghcb_hv_call(struct ghcb *ghcb, u64 exit_code, return ES_OK; } -void hv_ghcb_terminate(unsigned int set, unsigned int reason) +void __noreturn hv_ghcb_terminate(unsigned int set, unsigned int reason) { u64 val = GHCB_MSR_TERM_REQ; diff --git a/arch/x86/include/asm/mshyperv.h b/arch/x86/include/asm/mshyperv.h index 4c4c0ec3b62e..09c26e658bcc 100644 --- a/arch/x86/include/asm/mshyperv.h +++ b/arch/x86/include/asm/mshyperv.h @@ -212,7 +212,7 @@ int hv_set_mem_host_visibility(unsigned long addr, int numpages, bool visible); void hv_ghcb_msr_write(u64 msr, u64 value); void hv_ghcb_msr_read(u64 msr, u64 *value); bool hv_ghcb_negotiate_protocol(void); -void hv_ghcb_terminate(unsigned int set, unsigned int reason); +void __noreturn hv_ghcb_terminate(unsigned int set, unsigned int reason); #else static inline void hv_ghcb_msr_write(u64 msr, u64 value) {} static inline void hv_ghcb_msr_read(u64 msr, u64 *value) {} diff --git a/tools/objtool/check.c b/tools/objtool/check.c index 8586d4c36600..e23d12041be0 100644 --- a/tools/objtool/check.c +++ b/tools/objtool/check.c @@ -213,6 +213,7 @@ static bool __dead_end_function(struct objtool_file *file, struct symbol *func, "ex_handler_msr_mce", "fortify_panic", "hlt_play_dead", + "hv_ghcb_terminate", "kthread_complete_and_exit", "kthread_exit", "kunit_try_catch_throw",