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 lists.ozlabs.org (lists.ozlabs.org [112.213.38.117]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 8DE6BC433F5 for ; Fri, 28 Jan 2022 15:03:49 +0000 (UTC) Received: from boromir.ozlabs.org (localhost [IPv6:::1]) by lists.ozlabs.org (Postfix) with ESMTP id 4JlghM3V77z3cPj for ; Sat, 29 Jan 2022 02:03:47 +1100 (AEDT) Authentication-Results: lists.ozlabs.org; dkim=fail reason="signature verification failed" (2048-bit key; unprotected) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20201202 header.b=TAf70PRY; dkim-atps=neutral Authentication-Results: lists.ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=kernel.org (client-ip=145.40.68.75; helo=ams.source.kernel.org; envelope-from=nathan@kernel.org; receiver=) Authentication-Results: lists.ozlabs.org; dkim=pass (2048-bit key; unprotected) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20201202 header.b=TAf70PRY; dkim-atps=neutral Received: from ams.source.kernel.org (ams.source.kernel.org [145.40.68.75]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 4Jlggd3t51z30Kn for ; Sat, 29 Jan 2022 02:03:09 +1100 (AEDT) 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 ams.source.kernel.org (Postfix) with ESMTPS id 47807B8260D; Fri, 28 Jan 2022 15:03:04 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 428DFC340E6; Fri, 28 Jan 2022 15:03:01 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1643382183; bh=8977n+KmEj7ReKrjHl1AOxf+fEeuIQ9yNfDB243E+VA=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=TAf70PRYBmouertX+8zGnt2OA3GOBrW9BKCpiTUx/FKHWD8ko5NU1Vh8QZNSaxIwb sB0InlJEntDtGxIJ4eeYMQCU8lro++RobJOjjiEvmxbnmNuQIqxDXYt8gOJ0jscXHw 20aCKTLze0angQC074KZ8UKsg8Bu1tWavkoh0PxIYHT3qP+dLUM4HgchtUw7Jde4uG YKI+rDpnRCEBU8jJXzr+Cuy4RqV/RPLTwPRVyKG8pLNqEo/bxwcTbjvb2NW8asttuE BbXtKU8q3bRr9/sxWMA4m11Da4Ngdxry+oRzte9AU4thAGc1Ht26yOJn0gfjiW137D CHxtGdTxCj+Dg== Date: Fri, 28 Jan 2022 08:02:58 -0700 From: Nathan Chancellor To: Anders Roxell Subject: Re: [PATCHv3] powerpc: mm: radix_tlb: rearrange the if-else block Message-ID: References: <20220128131713.299198-1-anders.roxell@linaro.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20220128131713.299198-1-anders.roxell@linaro.org> X-BeenThere: linuxppc-dev@lists.ozlabs.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Arnd Bergmann , llvm@lists.linux.dev, ndesaulniers@google.com, linux-kernel@vger.kernel.org, linuxppc-dev@lists.ozlabs.org Errors-To: linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Sender: "Linuxppc-dev" On Fri, Jan 28, 2022 at 02:17:13PM +0100, Anders Roxell wrote: > Clang warns: > > arch/powerpc/mm/book3s64/radix_tlb.c:1191:23: error: variable 'hstart' is uninitialized when used here [-Werror,-Wuninitialized] > __tlbiel_va_range(hstart, hend, pid, > ^~~~~~ > arch/powerpc/mm/book3s64/radix_tlb.c:1175:23: note: initialize the variable 'hstart' to silence this warning > unsigned long hstart, hend; > ^ > = 0 > arch/powerpc/mm/book3s64/radix_tlb.c:1191:31: error: variable 'hend' is uninitialized when used here [-Werror,-Wuninitialized] > __tlbiel_va_range(hstart, hend, pid, > ^~~~ > arch/powerpc/mm/book3s64/radix_tlb.c:1175:29: note: initialize the variable 'hend' to silence this warning > unsigned long hstart, hend; > ^ > = 0 > 2 errors generated. > > Rework the 'if (IS_ENABLE(CONFIG_TRANSPARENT_HUGEPAGE))' so hstart/hend > always gets initialized, this will silence the warnings. That will also > simplify the 'else' path. Clang is getting confused with these warnings, > but the warnings is a false-positive. > > Suggested-by: Arnd Bergmann > Suggested-by: Nathan Chancellor > Reviewed-by: Christophe Leroy > Signed-off-by: Anders Roxell Reviewed-by: Nathan Chancellor > --- > arch/powerpc/mm/book3s64/radix_tlb.c | 11 ++++------- > 1 file changed, 4 insertions(+), 7 deletions(-) > > diff --git a/arch/powerpc/mm/book3s64/radix_tlb.c b/arch/powerpc/mm/book3s64/radix_tlb.c > index 7724af19ed7e..5172d5cec2c0 100644 > --- a/arch/powerpc/mm/book3s64/radix_tlb.c > +++ b/arch/powerpc/mm/book3s64/radix_tlb.c > @@ -1171,15 +1171,12 @@ static inline void __radix__flush_tlb_range(struct mm_struct *mm, > } > } > } else { > - bool hflush = false; > + bool hflush; > unsigned long hstart, hend; > > - if (IS_ENABLED(CONFIG_TRANSPARENT_HUGEPAGE)) { > - hstart = (start + PMD_SIZE - 1) & PMD_MASK; > - hend = end & PMD_MASK; > - if (hstart < hend) > - hflush = true; > - } > + hstart = (start + PMD_SIZE - 1) & PMD_MASK; > + hend = end & PMD_MASK; > + hflush = IS_ENABLED(CONFIG_TRANSPARENT_HUGEPAGE) && hstart < hend; > > if (type == FLUSH_TYPE_LOCAL) { > asm volatile("ptesync": : :"memory"); > -- > 2.34.1 >