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 476ABECAAA1 for ; Mon, 31 Oct 2022 17:58:51 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229648AbiJaR6t (ORCPT ); Mon, 31 Oct 2022 13:58:49 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:38412 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229562AbiJaR6r (ORCPT ); Mon, 31 Oct 2022 13:58:47 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 6DC3925D2 for ; Mon, 31 Oct 2022 10:58:45 -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 2BC2161358 for ; Mon, 31 Oct 2022 17:58:45 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 42533C433D6; Mon, 31 Oct 2022 17:58:41 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1667239124; bh=6k2VQy1WA5DlnNEe5C6X3CH+VCbSwygDOtxVDwcHUxQ=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=TG3DxQsxTlcQfXVv7G4OFe4KJMjGMhM0EI8q77eUAjnNDZPO3drtH5yiToccym/Ba MGUyKb0gPaJC5nmCymcOKRi4vmVrZsr9fvhxwV+HQptia9Jq3DToqW5xW2FXxxi+ma Jlt/XrBdfjs3zzz+4OFy3ZRqnbNzMjYLP5d9z7Lx1jwwzVMzClc0h5KTkg58RjnIQj dJO/i8/n6Mz8rQZqdMwS04c65w/rv83/xpRmtX/xDEsGeahktfvGEwO/4iICiUGaru 0fXQwHH67hG4RWHhMspJxFALhErCWudYh2GKeOoQ70SYboE1TPhVyz/Qb5TTa21gNM ZsWLHtcqSAccA== Date: Tue, 1 Nov 2022 01:49:01 +0800 From: Jisheng Zhang To: Conor Dooley Cc: Peter Zijlstra , Josh Poimboeuf , Jason Baron , Steven Rostedt , Ard Biesheuvel , Paul Walmsley , Palmer Dabbelt , Albert Ou , Nathan Chancellor , Nick Desaulniers , Tom Rix , linux-riscv@lists.infradead.org, linux-kernel@vger.kernel.org, llvm@lists.linux.dev, Samuel Holland , Andrew Jones Subject: Re: [PATCH v2] riscv: jump_label: mark arguments as const to satisfy asm constraints Message-ID: References: <20221008145437.491-1-jszhang@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Oct 12, 2022 at 02:28:16PM +0100, Conor Dooley wrote: > Hey Jisheng, Hi Conor, > LKP reported an error that seems to only have gone to myself & Samuel, > but the branch it's complaining about is your v1: > https://lore.kernel.org/lkml/202210122123.Cc4FPShJ-lkp@intel.com/ > > Any idea what the story is here? I tried the config in the link, I can reproduce the build error w/ and w/o the my patch. So I think the root cause of the build error is a different story. I have a fix in local repo, will send it out soon. Thanks > > Thanks, > Conor. > > On Sat, Oct 08, 2022 at 10:54:37PM +0800, Jisheng Zhang wrote: > > Samuel reported that the static branch usage in cpu_relax() breaks > > building with CONFIG_CC_OPTIMIZE_FOR_SIZE: > > > > In file included from : > > ./arch/riscv/include/asm/jump_label.h: In function 'cpu_relax': > > ././include/linux/compiler_types.h:285:33: warning: 'asm' operand 0 > > probably does not match constraints > > 285 | #define asm_volatile_goto(x...) asm goto(x) > > | ^~~ > > ./arch/riscv/include/asm/jump_label.h:41:9: note: in expansion of macro > > 'asm_volatile_goto' > > 41 | asm_volatile_goto( > > | ^~~~~~~~~~~~~~~~~ > > ././include/linux/compiler_types.h:285:33: error: impossible constraint > > in 'asm' > > 285 | #define asm_volatile_goto(x...) asm goto(x) > > | ^~~ > > ./arch/riscv/include/asm/jump_label.h:41:9: note: in expansion of macro > > 'asm_volatile_goto' > > 41 | asm_volatile_goto( > > | ^~~~~~~~~~~~~~~~~ > > make[1]: *** [scripts/Makefile.build:249: > > arch/riscv/kernel/vdso/vgettimeofday.o] Error 1 > > make: *** [arch/riscv/Makefile:128: vdso_prepare] Error 2 > > > > Maybe "-Os" prevents GCC from detecting that the key/branch arguments > > can be treated as constants and used as immediate operands. Inspired > > by x86's commit 864b435514b2("x86/jump_label: Mark arguments as const to > > satisfy asm constraints"), and as pointed out by Steven: "The "i" > > constraint needs to be a constant.", let's do similar modifications to > > riscv. > > > > Tested by CC_OPTIMIZE_FOR_SIZE + gcc and CC_OPTIMIZE_FOR_SIZE + clang. > > > > Link: https://lore.kernel.org/linux-riscv/20220922060958.44203-1-samuel@sholland.org/ > > Link: https://lore.kernel.org/all/20210212094059.5f8d05e8@gandalf.local.home/ > > Fixes: 8eb060e10185 ("arch/riscv: add Zihintpause support") > > Reported-by: Samuel Holland > > Signed-off-by: Jisheng Zhang > > Reviewed-by: Andrew Jones > > --- > > > > since v1: > > - add Reported-by, Reviewed-by, Fixes and Link tag > > > > arch/riscv/include/asm/jump_label.h | 8 ++++---- > > 1 file changed, 4 insertions(+), 4 deletions(-) > > > > diff --git a/arch/riscv/include/asm/jump_label.h b/arch/riscv/include/asm/jump_label.h > > index 38af2ec7b9bf..6d58bbb5da46 100644 > > --- a/arch/riscv/include/asm/jump_label.h > > +++ b/arch/riscv/include/asm/jump_label.h > > @@ -14,8 +14,8 @@ > > > > #define JUMP_LABEL_NOP_SIZE 4 > > > > -static __always_inline bool arch_static_branch(struct static_key *key, > > - bool branch) > > +static __always_inline bool arch_static_branch(struct static_key * const key, > > + const bool branch) > > { > > asm_volatile_goto( > > " .option push \n\t" > > @@ -35,8 +35,8 @@ static __always_inline bool arch_static_branch(struct static_key *key, > > return true; > > } > > > > -static __always_inline bool arch_static_branch_jump(struct static_key *key, > > - bool branch) > > +static __always_inline bool arch_static_branch_jump(struct static_key * const key, > > + const bool branch) > > { > > asm_volatile_goto( > > " .option push \n\t" > > -- > > 2.37.2 > >