From patchwork Thu Nov 17 20:29:05 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: 13047257 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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 88B0AC4167B for ; Thu, 17 Nov 2022 20:29:51 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S240183AbiKQU3u (ORCPT ); Thu, 17 Nov 2022 15:29:50 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:33462 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230287AbiKQU3k (ORCPT ); Thu, 17 Nov 2022 15:29:40 -0500 Received: from ams.source.kernel.org (ams.source.kernel.org [IPv6:2604:1380:4601:e00::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 3EEDA10BD; Thu, 17 Nov 2022 12:29:39 -0800 (PST) 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 EAEAAB821F8; Thu, 17 Nov 2022 20:29:37 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 399D6C433D7; Thu, 17 Nov 2022 20:29:33 +0000 (UTC) Authentication-Results: smtp.kernel.org; dkim=pass (1024-bit key) header.d=zx2c4.com header.i=@zx2c4.com header.b="J2Rh2Qpc" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=zx2c4.com; s=20210105; t=1668716972; 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=GUOLjwe2IeIpzWXOEF9lexW8mdcNzGTdZsyQ38BdoPo=; b=J2Rh2Qpc9DsvsDbF+m2czgSGbM5Ll5MOXAjDPCXLD2nTdJklt5tqKU6J+WcFuhyR7iOVNl nDsxVygX1V70q8oW1CY5Wrtm40Q0MuJ2+I1BvJvChEmmgguswnlvUmIux/9qEWHnssUi4g R46w+6Rv/8yOdUKBYQWT9WWQFkQmiLk= Received: by mail.zx2c4.com (ZX2C4 Mail Server) with ESMTPSA id 413bc89d (TLSv1.3:TLS_AES_256_GCM_SHA384:256:NO); Thu, 17 Nov 2022 20:29:32 +0000 (UTC) From: "Jason A. Donenfeld" To: linux-kernel@vger.kernel.org, patches@lists.linux.dev Cc: "Jason A. Donenfeld" , Kees Cook , Greg Kroah-Hartman , Jakub Kicinski , Russell King , Catalin Marinas , Thomas Bogendoerfer , Heiko Carstens , Herbert Xu , =?utf-8?q?Christoph_B=C3=B6hmwalder?= , Jani Nikula , Jason Gunthorpe , Sakari Ailus , "Martin K . Petersen" , Theodore Ts'o , Andreas Dilger , Jaegeuk Kim , Richard Weinberger , "Darrick J . Wong" , SeongJae Park , Thomas Gleixner , Andrew Morton , Michael Ellerman , Helge Deller , netdev@vger.kernel.org, linux-crypto@vger.kernel.org, linux-block@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-media@vger.kernel.org, linux-arm-kernel@lists.infradead.org, loongarch@lists.linux.dev, linux-mips@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, linux-mmc@vger.kernel.org, linux-parisc@vger.kernel.org Subject: [PATCH v3 2/3] treewide: use get_random_u32_{above,below}() instead of manual loop Date: Thu, 17 Nov 2022 21:29:05 +0100 Message-Id: <20221117202906.2312482-3-Jason@zx2c4.com> In-Reply-To: <20221117202906.2312482-1-Jason@zx2c4.com> References: <20221114164558.1180362-1-Jason@zx2c4.com> <20221117202906.2312482-1-Jason@zx2c4.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-media@vger.kernel.org These cases were done with this Coccinelle: @@ expression E; identifier I; @@ - do { ... when != I - I = get_random_u32(); ... when != I - } while (I > E); + I = get_random_u32_below(E + 1); @@ expression E; identifier I; @@ - do { ... when != I - I = get_random_u32(); ... when != I - } while (I >= E); + I = get_random_u32_below(E); @@ expression E; identifier I; @@ - do { ... when != I - I = get_random_u32(); ... when != I - } while (I < E); + I = get_random_u32_above(E - 1); @@ expression E; identifier I; @@ - do { ... when != I - I = get_random_u32(); ... when != I - } while (I <= E); + I = get_random_u32_above(E); @@ identifier I; @@ - do { ... when != I - I = get_random_u32(); ... when != I - } while (!I); + I = get_random_u32_above(0); @@ identifier I; @@ - do { ... when != I - I = get_random_u32(); ... when != I - } while (I == 0); + I = get_random_u32_above(0); @@ expression E; @@ - E + 1 + get_random_u32_below(U32_MAX - E) + get_random_u32_above(E) Reviewed-by: Greg Kroah-Hartman Signed-off-by: Jason A. Donenfeld Reviewed-by: Kees Cook --- fs/ext4/mmp.c | 8 +------- lib/test_fprobe.c | 5 +---- lib/test_kprobes.c | 5 +---- net/ipv6/output_core.c | 8 +------- net/vmw_vsock/af_vsock.c | 3 +-- 5 files changed, 5 insertions(+), 24 deletions(-) diff --git a/fs/ext4/mmp.c b/fs/ext4/mmp.c index 588cb09c5291..4681fff6665f 100644 --- a/fs/ext4/mmp.c +++ b/fs/ext4/mmp.c @@ -262,13 +262,7 @@ void ext4_stop_mmpd(struct ext4_sb_info *sbi) */ static unsigned int mmp_new_seq(void) { - u32 new_seq; - - do { - new_seq = get_random_u32(); - } while (new_seq > EXT4_MMP_SEQ_MAX); - - return new_seq; + return get_random_u32_below(EXT4_MMP_SEQ_MAX + 1); } /* diff --git a/lib/test_fprobe.c b/lib/test_fprobe.c index e0381b3ec410..1fb56cf5e5ce 100644 --- a/lib/test_fprobe.c +++ b/lib/test_fprobe.c @@ -144,10 +144,7 @@ static unsigned long get_ftrace_location(void *func) static int fprobe_test_init(struct kunit *test) { - do { - rand1 = get_random_u32(); - } while (rand1 <= div_factor); - + rand1 = get_random_u32_above(div_factor); target = fprobe_selftest_target; target2 = fprobe_selftest_target2; target_ip = get_ftrace_location(target); diff --git a/lib/test_kprobes.c b/lib/test_kprobes.c index eeb1d728d974..1c95e5719802 100644 --- a/lib/test_kprobes.c +++ b/lib/test_kprobes.c @@ -339,10 +339,7 @@ static int kprobes_test_init(struct kunit *test) stacktrace_target = kprobe_stacktrace_target; internal_target = kprobe_stacktrace_internal_target; stacktrace_driver = kprobe_stacktrace_driver; - - do { - rand1 = get_random_u32(); - } while (rand1 <= div_factor); + rand1 = get_random_u32_above(div_factor); return 0; } diff --git a/net/ipv6/output_core.c b/net/ipv6/output_core.c index 2685c3f15e9d..b5205311f372 100644 --- a/net/ipv6/output_core.c +++ b/net/ipv6/output_core.c @@ -15,13 +15,7 @@ static u32 __ipv6_select_ident(struct net *net, const struct in6_addr *dst, const struct in6_addr *src) { - u32 id; - - do { - id = get_random_u32(); - } while (!id); - - return id; + return get_random_u32_above(0); } /* This function exists only for tap drivers that must support broken diff --git a/net/vmw_vsock/af_vsock.c b/net/vmw_vsock/af_vsock.c index ff38c5a4d174..d593d5b6d4b1 100644 --- a/net/vmw_vsock/af_vsock.c +++ b/net/vmw_vsock/af_vsock.c @@ -626,8 +626,7 @@ static int __vsock_bind_connectible(struct vsock_sock *vsk, struct sockaddr_vm new_addr; if (!port) - port = LAST_RESERVED_PORT + 1 + - get_random_u32_below(U32_MAX - LAST_RESERVED_PORT); + port = get_random_u32_above(LAST_RESERVED_PORT); vsock_addr_init(&new_addr, addr->svm_cid, addr->svm_port);