From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-out.m-online.net (mail-out.m-online.net [212.18.0.10]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id BFB7B3D88F7; Sat, 26 Sep 2026 09:48:03 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=212.18.0.10 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790416086; cv=none; b=axT9bThcP0gL3FUJ4SjKeUhotD2drSVJ4qnQsV9Z8pCKdaJyhj7P/5/yGQdAavpZ9PTFxUKXyYBssG96JjqVqt3/7+OvykdOz4fBjP+UOiDt55+H/76LyP+/QhUI+ZMhMOmFb84140qdJZPyo2uxYoDjwTF88I1vmdlk4ZiYHbI= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790416086; c=relaxed/simple; bh=KSRclUbiChdvva1viNPPMjblDnBYwYSw9BmIEoDsjIM=; h=From:To:Cc:Subject:In-Reply-To:References:Date:Message-ID: MIME-Version:Content-Type; b=LBtGsg9sPCQ8UcQH+ECD29AwBQpOaBgz4cduYxAo9+Bg4WDbRcFvKrTWxJb2VQR755HFQmxeaJcvcGL2bMzrddZlNFhFNJep6DJLsOYktaACvIVvjJrVGYj3maoyJilUmb1LZQHCB3d3WJAd53CiAmj4Phul8jr9fGySe9O1zMk= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=linux-m68k.org; spf=pass smtp.mailfrom=nefkom.net; arc=none smtp.client-ip=212.18.0.10 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=linux-m68k.org Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=nefkom.net Received: from mail-out.m-online.net (mail-out.m-online.net [212.18.0.10]) by mail-out.m-online.net (Postfix) with ESMTP id 4hsMx95lHWz1sPSD; Sat, 26 Sep 2026 11:39:57 +0200 (CEST) Received: from frontend03.mail.m-online.net (unknown [192.168.6.182]) by mail-out.m-online.net (Postfix) with ESMTP id 4hsMx35nYKz1sPRy; Sat, 26 Sep 2026 11:39:51 +0200 (CEST) Received: from localhost (dynscan3.mnet-online.de [192.168.6.87]) by mail.m-online.net (Postfix) with ESMTP id 4hsMx319yNz1qqlR; Sat, 26 Sep 2026 11:39:51 +0200 (CEST) X-Virus-Scanned: amavis at mnet-online.de Received: from mail.mnet-online.de ([192.168.6.182]) by localhost (dynscan3.mail.m-online.net [192.168.6.87]) (amavis, port 10024) with ESMTP id r0-zxGatOHrc; Sat, 26 Sep 2026 11:39:43 +0200 (CEST) X-Auth-Info: wFe88JiXbDxEAWB88fOER1RGk4p+sTXtzQeYAh7Q9amIwrx952rztx0YkIPQk3RO Received: from tiger (aftr-82-135-83-101.dynamic.mnet-online.de [82.135.83.101]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange ECDHE (P-256) server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mail.mnet-online.de (Postfix) with ESMTPSA; Sat, 26 Sep 2026 11:39:43 +0200 (CEST) From: Andreas Schwab To: Nathan Chancellor Cc: Andy Lutomirski , Thomas Gleixner , Theodore Ts'o , "Jason A. Donenfeld" , Vincenzo Frascino , Nick Desaulniers , Bill Wendling , Justin Stitt , Catalin Marinas , Will Deacon , Mark Rutland , Huacai Chen , WANG Xuerui , Madhavan Srinivasan , Michael Ellerman , Nicholas Piggin , "Christophe Leroy (CS GROUP)" , Paul Walmsley , Palmer Dabbelt , Albert Ou , Alexandre Ghiti , Heiko Carstens , Vasily Gorbik , Alexander Gordeev , Christian Borntraeger , Sven Schnelle , Ingo Molnar , Borislav Petkov , Dave Hansen , "H. Peter Anvin" , x86@kernel.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, loongarch@lists.linux.dev, linuxppc-dev@lists.ozlabs.org, linux-riscv@lists.infradead.org, linux-s390@vger.kernel.org, llvm@lists.linux.dev Subject: Re: [PATCH v2] random: vDSO: Avoid call to memset() when zeroing reserved in __cvdso_getrandom_data() In-Reply-To: <20260925-vdso-getrandom-avoid-memset-llvm-24-v2-1-ce640f872393@kernel.org> References: <20260925-vdso-getrandom-avoid-memset-llvm-24-v2-1-ce640f872393@kernel.org> Date: Sat, 26 Sep 2026 11:39:43 +0200 Message-ID: <87zex4ic68.fsf@linux-m68k.org> User-Agent: Gnus/5.13 (Gnus v5.13) Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain On Sep 25 2026, Nathan Chancellor wrote: > +#if __has_builtin(__builtin_memset_inline) > +#define memset_inline(dst, value, size) __builtin_memset_inline(dst, value, size) > +#elif IS_ENABLED(CONFIG_CC_HAS_OPT_INLINE_MEMSET) > +#define memset_inline(dst, value, size) __builtin_memset(dst, value, size) > +#else > +static inline void *memset_inline(void *dst, int value, size_t size) > +{ > + char *d = dst; > + > + while (size--) > + *d++ = value; > + > + return d; > +} > +#endif > + memset actually returns the original pointer, not the incremented one. Nothing uses the return value of memset_inline here, but it is confusing. -- Andreas Schwab, schwab@linux-m68k.org GPG Key fingerprint = 7578 EB47 D4E5 4D69 2510 2552 DF73 E780 A9DA AEC1 "And now for something completely different."