From patchwork Thu Nov 24 16:10:27 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: =?utf-8?q?Alex_Benn=C3=A9e?= X-Patchwork-Id: 9446011 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 762516075F for ; Thu, 24 Nov 2016 16:16:19 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 67E0E27F0B for ; Thu, 24 Nov 2016 16:16:19 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 5A463280DE; Thu, 24 Nov 2016 16:16:19 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-4.1 required=2.0 tests=BAYES_00,DKIM_SIGNED, RCVD_IN_DNSWL_MED,T_DKIM_INVALID autolearn=ham version=3.3.1 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.9]) (using TLSv1.2 with cipher AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id D065B280D0 for ; Thu, 24 Nov 2016 16:16:15 +0000 (UTC) Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.85_2 #1 (Red Hat Linux)) id 1c9wee-0005My-DJ; Thu, 24 Nov 2016 16:13:44 +0000 Received: from mail-wm0-x233.google.com ([2a00:1450:400c:c09::233]) by bombadil.infradead.org with esmtps (Exim 4.85_2 #1 (Red Hat Linux)) id 1c9wcR-0003Ql-H2 for linux-arm-kernel@lists.infradead.org; Thu, 24 Nov 2016 16:11:36 +0000 Received: by mail-wm0-x233.google.com with SMTP id a197so119260826wmd.0 for ; Thu, 24 Nov 2016 08:11:07 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=RDVSUnk6Qvzm8R55CWJrewMJijlfHwvftktk5uMonIs=; b=HgLNQsdxQsN/VZBtIDQ8pHuZWjAWFawl/A3kcR21tlgqMOKqLO80HSRS09y/F8PEUh 2LY7fFrfLGsZM62TmxlVhBRxC2x6LgDoUJjRPlaQlTrTK4f2iexvXxBDWez37GkGz8dM 0PO9Z8QKznZovUd4Pj1ps/QOuepKVw72bYUXY= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20130820; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=RDVSUnk6Qvzm8R55CWJrewMJijlfHwvftktk5uMonIs=; b=gXPE3yEToVhmKFpWyn1Uwah8vs3WKQhZrEIwiIxI373I/jFubca1ccexrPbtEix2MS wQ/7Aptk1NreSZSGghSDajLtfDvSbLB6NxmbSoU6ZpHvcJsyWTKvHoi2cHOenVbGskVN IwVFQHy1t8/ANUWgsT4tSrD+Atv1cHEbMVyFSKISqF0KnapLVqoJ6RuhF9pEY3coOcuj fww7HG5X27iMatK8/ppL2Pt4quwtqreTcFFdNQevut7buR81ySNJnt6wfeZGzzazenAY hbZ3FjdU6HS6s+l+cMqmiGMjVppsTTBAut6ohOuh8RlhKLs9BZfhA31f+GVMJCGgpPwT h3fQ== X-Gm-Message-State: AKaTC007qhROsZatNWsDiDQNTrPgmiojLrAxo9B0GZCdv+ZeEq/H4N0ciYqvvrbn4HQMwK6V X-Received: by 10.28.107.21 with SMTP id g21mr3122627wmc.131.1480003865564; Thu, 24 Nov 2016 08:11:05 -0800 (PST) Received: from zen.linaro.local ([81.128.185.34]) by smtp.gmail.com with ESMTPSA id ef10sm23012196wjd.22.2016.11.24.08.11.02 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Thu, 24 Nov 2016 08:11:02 -0800 (PST) Received: from zen.linaroharston (localhost [127.0.0.1]) by zen.linaro.local (Postfix) with ESMTP id 0BD0B3E0563; Thu, 24 Nov 2016 16:11:00 +0000 (GMT) From: =?UTF-8?q?Alex=20Benn=C3=A9e?= To: kvm@vger.kernel.org, linux-arm-kernel@lists.infradead.org, kvmarm@lists.cs.columbia.edu, christoffer.dall@linaro.org, marc.zyngier@arm.com Subject: [kvm-unit-tests PATCH v7 05/11] lib: add isaac prng library from CCAN Date: Thu, 24 Nov 2016 16:10:27 +0000 Message-Id: <20161124161033.11456-6-alex.bennee@linaro.org> X-Mailer: git-send-email 2.10.1 In-Reply-To: <20161124161033.11456-1-alex.bennee@linaro.org> References: <20161124161033.11456-1-alex.bennee@linaro.org> MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20161124_081128_086362_D3B85806 X-CRM114-Status: GOOD ( 20.64 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.20 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: mttcg@listserver.greensocs.com, peter.maydell@linaro.org, claudio.fontana@huawei.com, nikunj@linux.vnet.ibm.com, jan.kiszka@siemens.com, mark.burton@greensocs.com, a.rigo@virtualopensystems.com, qemu-devel@nongnu.org, "Timothy B . Terriberry" , cota@braap.org, serge.fdrv@gmail.com, pbonzini@redhat.com, bobby.prani@gmail.com, rth@twiddle.net, =?UTF-8?q?Alex=20Benn=C3=A9e?= , fred.konrad@greensocs.com Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org X-Virus-Scanned: ClamAV using ClamSMTP It's often useful to introduce some sort of random variation when testing several racing CPU conditions. Instead of each test implementing some half-arsed PRNG bring in a a decent one which has good statistical randomness. Obviously it is deterministic for a given seed value which is likely the behaviour you want. I've pulled in the ISAAC library from CCAN: http://ccodearchive.net/info/isaac.html I shaved off the float related stuff which is less useful for unit testing and re-indented to fit the style. The original license was CC0 (Public Domain) which is compatible with the LGPL v2 of kvm-unit-tests. Signed-off-by: Alex Bennée CC: Timothy B. Terriberry Acked-by: Andrew Jones --- arm/Makefile.common | 1 + lib/prng.c | 162 ++++++++++++++++++++++++++++++++++++++++++++++++++++ lib/prng.h | 82 ++++++++++++++++++++++++++ 3 files changed, 245 insertions(+) create mode 100644 lib/prng.c create mode 100644 lib/prng.h diff --git a/arm/Makefile.common b/arm/Makefile.common index 6c0898f..52f7440 100644 --- a/arm/Makefile.common +++ b/arm/Makefile.common @@ -40,6 +40,7 @@ cflatobjs += lib/pci-testdev.o cflatobjs += lib/virtio.o cflatobjs += lib/virtio-mmio.o cflatobjs += lib/chr-testdev.o +cflatobjs += lib/prng.o cflatobjs += lib/arm/io.o cflatobjs += lib/arm/setup.o cflatobjs += lib/arm/mmu.o diff --git a/lib/prng.c b/lib/prng.c new file mode 100644 index 0000000..ebd6df7 --- /dev/null +++ b/lib/prng.c @@ -0,0 +1,162 @@ +/* + * Pseudo Random Number Generator + * + * Lifted from ccan modules ilog/isaac under CC0 + * - http://ccodearchive.net/info/isaac.html + * - http://ccodearchive.net/info/ilog.html + * + * And lightly hacked to compile under the KVM unit test environment. + * This provides a handy RNG for torture tests that want to vary + * delays and the like. + * + */ + +/*Written by Timothy B. Terriberry (tterribe@xiph.org) 1999-2009. + CC0 (Public domain) - see LICENSE file for details + Based on the public domain implementation by Robert J. Jenkins Jr.*/ + +#include "libcflat.h" + +#include +#include "prng.h" + +#define ISAAC_MASK (0xFFFFFFFFU) + +/* Extract ISAAC_SZ_LOG bits (starting at bit 2). */ +static inline uint32_t lower_bits(uint32_t x) +{ + return (x & ((ISAAC_SZ-1) << 2)) >> 2; +} + +/* Extract next ISAAC_SZ_LOG bits (starting at bit ISAAC_SZ_LOG+2). */ +static inline uint32_t upper_bits(uint32_t y) +{ + return (y >> (ISAAC_SZ_LOG+2)) & (ISAAC_SZ-1); +} + +static void isaac_update(isaac_ctx *_ctx){ + uint32_t *m; + uint32_t *r; + uint32_t a; + uint32_t b; + uint32_t x; + uint32_t y; + int i; + m=_ctx->m; + r=_ctx->r; + a=_ctx->a; + b=_ctx->b+(++_ctx->c); + for(i=0;i>6)+m[i+ISAAC_SZ/2]; + m[i]=y=m[lower_bits(x)]+a+b; + r[i]=b=m[upper_bits(y)]+x; + x=m[++i]; + a=(a^a<<2)+m[i+ISAAC_SZ/2]; + m[i]=y=m[lower_bits(x)]+a+b; + r[i]=b=m[upper_bits(y)]+x; + x=m[++i]; + a=(a^a>>16)+m[i+ISAAC_SZ/2]; + m[i]=y=m[lower_bits(x)]+a+b; + r[i]=b=m[upper_bits(y)]+x; + } + for(i=ISAAC_SZ/2;i>6)+m[i-ISAAC_SZ/2]; + m[i]=y=m[lower_bits(x)]+a+b; + r[i]=b=m[upper_bits(y)]+x; + x=m[++i]; + a=(a^a<<2)+m[i-ISAAC_SZ/2]; + m[i]=y=m[lower_bits(x)]+a+b; + r[i]=b=m[upper_bits(y)]+x; + x=m[++i]; + a=(a^a>>16)+m[i-ISAAC_SZ/2]; + m[i]=y=m[lower_bits(x)]+a+b; + r[i]=b=m[upper_bits(y)]+x; + } + _ctx->b=b; + _ctx->a=a; + _ctx->n=ISAAC_SZ; +} + +static void isaac_mix(uint32_t _x[8]){ + static const unsigned char SHIFT[8]={11,2,8,16,10,4,8,9}; + int i; + for(i=0;i<8;i++){ + _x[i]^=_x[(i+1)&7]<>SHIFT[i]; + _x[(i+3)&7]+=_x[i]; + _x[(i+1)&7]+=_x[(i+2)&7]; + } +} + + +void isaac_init(isaac_ctx *_ctx,const unsigned char *_seed,int _nseed){ + _ctx->a=_ctx->b=_ctx->c=0; + memset(_ctx->r,0,sizeof(_ctx->r)); + isaac_reseed(_ctx,_seed,_nseed); +} + +void isaac_reseed(isaac_ctx *_ctx,const unsigned char *_seed,int _nseed){ + uint32_t *m; + uint32_t *r; + uint32_t x[8]; + int i; + int j; + m=_ctx->m; + r=_ctx->r; + if(_nseed>ISAAC_SEED_SZ_MAX)_nseed=ISAAC_SEED_SZ_MAX; + for(i=0;i<_nseed>>2;i++){ + r[i]^=(uint32_t)_seed[i<<2|3]<<24|(uint32_t)_seed[i<<2|2]<<16| + (uint32_t)_seed[i<<2|1]<<8|_seed[i<<2]; + } + _nseed-=i<<2; + if(_nseed>0){ + uint32_t ri; + ri=_seed[i<<2]; + for(j=1;j<_nseed;j++)ri|=(uint32_t)_seed[i<<2|j]<<(j<<3); + r[i++]^=ri; + } + x[0]=x[1]=x[2]=x[3]=x[4]=x[5]=x[6]=x[7]=0x9E3779B9U; + for(i=0;i<4;i++)isaac_mix(x); + for(i=0;in)isaac_update(_ctx); + return _ctx->r[--_ctx->n]; +} + +uint32_t isaac_next_uint(isaac_ctx *_ctx,uint32_t _n){ + uint32_t r; + uint32_t v; + uint32_t d; + do{ + r=isaac_next_uint32(_ctx); + v=r%_n; + d=r-v; + } + while(((d+_n-1)&ISAAC_MASK) + + + +typedef struct isaac_ctx isaac_ctx; + + + +/*This value may be lowered to reduce memory usage on embedded platforms, at + the cost of reducing security and increasing bias. + Quoting Bob Jenkins: "The current best guess is that bias is detectable after + 2**37 values for [ISAAC_SZ_LOG]=3, 2**45 for 4, 2**53 for 5, 2**61 for 6, + 2**69 for 7, and 2**77 values for [ISAAC_SZ_LOG]=8."*/ +#define ISAAC_SZ_LOG (8) +#define ISAAC_SZ (1<