From patchwork Tue Apr 19 11:16:49 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: 12817930 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 67A07C433FE for ; Tue, 19 Apr 2022 11:26:05 +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=uVEep19F3PoO1VWyevm/+bJEAEY+2RWNe405/iqoIu8=; b=s+QtEPhvd8sUUY tpOD24F6LU0FwOfE8vYO81HoicBxXgzPDBYRIgmSWNW8dCF5mqqrUBbnDkMyfAM9DS3hHPrUAIoin a6NNk+Hgb0hLYFIehhUMW25w0jUyMFX7hQWULRPVZaTf3N7OuLElCpj26jRqNssMjPD8vXhMLMFLb CJ6WxqBteH4KGwByoLFSi4LQYMOxB4y28VQKykbKzPrnwuqwvRJoEGEhRT6TpJT/sZ59jPClhzQ/L HjDiatN9V7iorVXCSJDgqy8CVKJ1j/WyiZEBaO0ehcAJdKBxmRtfo8GQwnTECU3IufCQdKFgairsj AxJkjzYswDKkqNUF2LSA==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1nglzV-0036ko-0m; Tue, 19 Apr 2022 11:25:53 +0000 Received: from sin.source.kernel.org ([145.40.73.55]) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1nglsJ-0032Py-V0; Tue, 19 Apr 2022 11:18:29 +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 sin.source.kernel.org (Postfix) with ESMTPS id 2BB8ECE183D; Tue, 19 Apr 2022 11:18:26 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 40082C385A5; Tue, 19 Apr 2022 11:18:21 +0000 (UTC) Authentication-Results: smtp.kernel.org; dkim=pass (1024-bit key) header.d=zx2c4.com header.i=@zx2c4.com header.b="WMRyA3CF" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=zx2c4.com; s=20210105; t=1650367100; 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=gMuiTScdp7c+tPntikHvEFRo+YYqSeslWu8YJFI7ND8=; b=WMRyA3CFNbdyp34FeludSbEser62S5VAE1An7x3hl/B7AX1FxzRgKvDjyTyuyVftZeN1GH IQeMKMQgOEzCGyrwqxQU6QfgVwxbKflb65cSTLDyvOjWU+vPMi5u9W6iGPRopjpQgIu5aT 2gJrkjy25rRhXz54zTJAnGQERvAq+c8= Received: by mail.zx2c4.com (ZX2C4 Mail Server) with ESMTPSA id e99bdedc (TLSv1.3:AEAD-AES256-GCM-SHA384:256:NO); Tue, 19 Apr 2022 11:18:20 +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 , 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 v5 10/11] xtensa: use fallback for random_get_entropy() instead of zero Date: Tue, 19 Apr 2022 13:16:49 +0200 Message-Id: <20220419111650.1582274-11-Jason@zx2c4.com> In-Reply-To: <20220419111650.1582274-1-Jason@zx2c4.com> References: <20220419111650.1582274-1-Jason@zx2c4.com> MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20220419_041828_403651_7184E16D X-CRM114-Status: GOOD ( 17.11 ) X-BeenThere: linux-riscv@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-riscv" Errors-To: linux-riscv-bounces+linux-riscv=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 random_get_entropy_fallback() would be preferable, because that always needs to return _something_, even falling back to jiffies eventually. It's not as though random_get_entropy_fallback() 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: Max Filippov Signed-off-by: Jason A. Donenfeld Acked-by: Max Filippov --- arch/xtensa/include/asm/timex.h | 6 ++---- 1 file changed, 2 insertions(+), 4 deletions(-) diff --git a/arch/xtensa/include/asm/timex.h b/arch/xtensa/include/asm/timex.h index 233ec75e60c6..3f2462f2d027 100644 --- a/arch/xtensa/include/asm/timex.h +++ b/arch/xtensa/include/asm/timex.h @@ -29,10 +29,6 @@ extern unsigned long ccount_freq; -typedef unsigned long long cycles_t; - -#define get_cycles() (0) - void local_timer_setup(unsigned cpu); /* @@ -59,4 +55,6 @@ static inline void set_linux_timer (unsigned long ccompare) xtensa_set_sr(ccompare, SREG_CCOMPARE + LINUX_TIMER); } +#include + #endif /* _XTENSA_TIMEX_H */