From patchwork Sun Apr 10 21:49:50 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Jason A. Donenfeld" X-Patchwork-Id: 12808318 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 bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (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 44E80C433EF for ; Sun, 10 Apr 2022 21:56:38 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:References:In-Reply-To: Message-Id:Date:Subject:Cc:To:From:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=pt3uSigB698u8rtwtjPDEnG+c3O/quXXw6GtqvIWA1g=; b=WAzkj++pWDKHnN MZMxExbTX11vae+jotrZ6nIw5GexS8C36XCRFObwDdrEH15xu2wKTgpoOCwgDFs4GwAEGNI1sNTSl Dj4V1bxffEngQN2SFBKCeTctSFKdrWP8/Da/aKKVhdom2/tuVp3OHAAxA23RYJpjw0ExpnjIljqTa +583qHttZY+NesKM73Eyfz168FVTwNt1T+S33YLbb4KKSqIkhypQZ/O4hb4hHwymtT/49l/z7A4z0 NeG47ypib2zEJef9e3YmTnu8/JpcmWbbzNcC2t7sqblBHYFLHHkI+5cUNdnjoJX3Iw59RgLyuBXqM RuQgUzwUDLPqz1pW264A==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1ndfWt-005dbV-2u; Sun, 10 Apr 2022 21:55:31 +0000 Received: from dfw.source.kernel.org ([2604:1380:4641:c500::1]) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1ndfSf-005avf-Vg; Sun, 10 Apr 2022 21:51:11 +0000 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 79DD260C8B; Sun, 10 Apr 2022 21:51:09 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 9F5A8C385A4; Sun, 10 Apr 2022 21:51:05 +0000 (UTC) Authentication-Results: smtp.kernel.org; dkim=pass (1024-bit key) header.d=zx2c4.com header.i=@zx2c4.com header.b="oK1G66UK" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=zx2c4.com; s=20210105; t=1649627464; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=C1ufLrONysCe3yEQR0EDgg6+4J7GIerx7v+cUIeDJoo=; b=oK1G66UKLQjisT2dZxHPb7eiQBb5LINqc5DrHQew1fp5uC96tVgAxXsU3uDN5LoBwvFOTm S28h0ZByMgUKvgHs+QYLek1FYfCRt1ZeOmNdOM5rt3/n+i5UDEqjb9HogOfuXe8TY+jcXJ SdLf2gX1e9o1Q+cykNqxXlo/2kXiymU= Received: by mail.zx2c4.com (ZX2C4 Mail Server) with ESMTPSA id 02e0bab8 (TLSv1.3:AEAD-AES256-GCM-SHA384:256:NO); Sun, 10 Apr 2022 21:51:04 +0000 (UTC) From: "Jason A. Donenfeld" To: linux-kernel@vger.kernel.org, linux-crypto@vger.kernel.org, tglx@linutronix.de, arnd@arndb.de Cc: "Jason A. Donenfeld" , Theodore Ts'o , Dominik Brodowski , Russell King , Catalin Marinas , Will Deacon , Geert Uytterhoeven , Thomas Bogendoerfer , Paul Walmsley , Palmer Dabbelt , Albert Ou , "David S . Miller" , Richard Weinberger , Anton Ivanov , Johannes Berg , Ingo Molnar , Borislav Petkov , Dave Hansen , "H . Peter Anvin" , Chris Zankel , Max Filippov , John Stultz , Stephen Boyd , Dinh Nguyen , linux-arm-kernel@lists.infradead.org, linux-m68k@lists.linux-m68k.org, linux-mips@vger.kernel.org, linux-riscv@lists.infradead.org, sparclinux@vger.kernel.org, linux-um@lists.infradead.org, x86@kernel.org, linux-xtensa@linux-xtensa.org Subject: [PATCH v2 10/11] sparc: use ktime_read_raw_clock() for random_get_entropy() instead of zero Date: Sun, 10 Apr 2022 23:49:50 +0200 Message-Id: <20220410214951.55294-11-Jason@zx2c4.com> In-Reply-To: <20220410214951.55294-1-Jason@zx2c4.com> References: <20220410214951.55294-1-Jason@zx2c4.com> MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20220410_145110_141355_DE8A6F29 X-CRM114-Status: GOOD ( 15.74 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org In the event that random_get_entropy() can't access a cycle counter or similar, falling back to returning 0 is really not the best we can do. Instead, at least calling ktime_read_raw_clock() would be preferable, because that always needs to return _something_, even falling back to jiffies eventually. It's not as though ktime_read_raw_clock() is super high precision or guaranteed to be entropic, but basically anything that's not zero all the time is better than returning zero all the time. This is accomplished by just including the asm-generic code like on other architectures, which means we can get rid of the empty stub function here. Cc: Thomas Gleixner Cc: Arnd Bergmann Cc: David S. Miller Signed-off-by: Jason A. Donenfeld --- arch/sparc/include/asm/timex_32.h | 4 +--- 1 file changed, 1 insertion(+), 3 deletions(-) diff --git a/arch/sparc/include/asm/timex_32.h b/arch/sparc/include/asm/timex_32.h index 542915b46209..f86326a6f89e 100644 --- a/arch/sparc/include/asm/timex_32.h +++ b/arch/sparc/include/asm/timex_32.h @@ -9,8 +9,6 @@ #define CLOCK_TICK_RATE 1193180 /* Underlying HZ */ -/* XXX Maybe do something better at some point... -DaveM */ -typedef unsigned long cycles_t; -#define get_cycles() (0) +#include #endif