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[2620:137:e000::1:20]) by mx.google.com with ESMTP id m4-20020a1709062b8400b0073155abc1b8si13257325ejg.154.2022.10.19.20.53.17; Wed, 19 Oct 2022 20:53:44 -0700 (PDT) Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20; Authentication-Results: mx.google.com; dkim=pass header.i=@gmail.com header.s=20210112 header.b=Tc1hvzFM; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=pass (p=NONE sp=QUARANTINE dis=NONE) header.from=gmail.com Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229664AbiJTDZB (ORCPT + 99 others); Wed, 19 Oct 2022 23:25:01 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:44992 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229558AbiJTDY6 (ORCPT ); Wed, 19 Oct 2022 23:24:58 -0400 Received: from mail-oi1-x22f.google.com (mail-oi1-x22f.google.com [IPv6:2607:f8b0:4864:20::22f]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 3900342D6B for ; Wed, 19 Oct 2022 20:24:56 -0700 (PDT) Received: by mail-oi1-x22f.google.com with SMTP id n130so21481722oia.6 for ; Wed, 19 Oct 2022 20:24:55 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to; bh=OczjChBmGkUsoBfYt2005Z8T2ggpJvwmMFUd3PcsLKA=; b=Tc1hvzFMF23lt+BFLnxI7WX4sMpYoLkFxJzxHhJETh1MSfcQuJmAP341e2KQwFTJsJ EmLReN2GxQD4lz92lcUHSQnuNWQr+mBaXao4mrC+eJMAnpohWbG/2WgPmvzOzZWHP9wH 6y5TEKgsLspmLNtSj9KNcWSRSj7Z8e8+O1Mq6mXoC8pfEJhSTLc1v96I+wIo4/qn6tsh Y/p71MWFrA/EB1d1oVFjdb10h2jTvoId9QBa67aCSbWtUNWbJSY/syidxU0LOd2jj0qi Z7ElXW8pg1UF7dTM0vhyEWbpSjd3/yZWoC4ApPo5xsHPCego3IonNbj+cWRTaZVgR0tl 1sxA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=OczjChBmGkUsoBfYt2005Z8T2ggpJvwmMFUd3PcsLKA=; b=t/9fn/lelGXNp8Kx6fe72kmoDF/cPzlAVKtE6qlcfB9WwBfytNauvxCfJzXmef+Yiy Z6+5xGv7KNRT/SMF5Y6F1P0zBkKuRZ5+O+BRhtuZU9Lyqw8pVSV3aBsVx21oegUhLj/L sHALfVSmnMV/7e7BsDJNF2TyO1G84gba6Jl5CL+NvjYqb+9pqJSwHI/52Pen7u8YsB+G 77KqbfvjSdd+HmftQUjikxNdE8qDYyY7eGRzbSc9EllMiJcSWIDC7KHIsaue53pOfdyF B0UMs8drQsZd1Dh8B+reUhFJarxRTg3F8362hP0UI3E9uZFBs2yPWGwD8nUWqp4DjZwa rSMg== X-Gm-Message-State: ACrzQf1fpYLH942fsUz8t/7cC8yzwjG3NuhYxzMKO0CSUUxg6LHiWDK8 4QOwkjCNPyiKPXpj/L4YElY= X-Received: by 2002:aca:df8b:0:b0:350:e9a8:1627 with SMTP id w133-20020acadf8b000000b00350e9a81627mr20314745oig.68.1666236295217; Wed, 19 Oct 2022 20:24:55 -0700 (PDT) Received: from localhost ([12.97.180.36]) by smtp.gmail.com with ESMTPSA id y3-20020a056870418300b0011f400edb17sm8450627oac.4.2022.10.19.20.24.54 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 19 Oct 2022 20:24:54 -0700 (PDT) From: Yury Norov To: "Russell King (Oracle)" , Catalin Marinas , Mark Rutland , Will Deacon , linux-arm-kernel@lists.infradead.org Cc: Yury Norov , Linux Kernel Mailing List , Alexey Klimov , Andy Shevchenko , Andy Whitcroft , Dennis Zhou , Geert Uytterhoeven , Guenter Roeck , Kees Cook , Linus Torvalds , Rasmus Villemoes Subject: [PATCH 1/2] bitmap: add sanity check function for find_bit() Date: Wed, 19 Oct 2022 20:20:23 -0700 Message-Id: <20221020032024.1804535-2-yury.norov@gmail.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20221020032024.1804535-1-yury.norov@gmail.com> References: <20221020032024.1804535-1-yury.norov@gmail.com> MIME-Version: 1.0 X-Spam-Status: No, score=-2.1 required=5.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,FREEMAIL_FROM, RCVD_IN_DNSWL_NONE,SPF_HELO_NONE,SPF_PASS autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on lindbergh.monkeyblade.net Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org X-getmail-retrieved-from-mailbox: =?utf-8?q?INBOX?= X-GMAIL-THRID: =?utf-8?q?1747177202739688063?= X-GMAIL-MSGID: =?utf-8?q?1747177202739688063?= find_bit() requires a pointer aligned to it's size. However some subsystems (fs, for example) cast char* variables to unsigned long* before passing them to find_bit(). Many architectures allow unaligned pointers with the cost of performance degradation. This patch adds runtime check for the pointers to be aligned. Signed-off-by: Yury Norov --- include/linux/find.h | 35 +++++++++++++++++++++++++++++++++++ lib/Kconfig.debug | 7 +++++++ 2 files changed, 42 insertions(+) diff --git a/include/linux/find.h b/include/linux/find.h index ccaf61a0f5fd..2d8f5419d787 100644 --- a/include/linux/find.h +++ b/include/linux/find.h @@ -7,6 +7,7 @@ #endif #include +#include unsigned long _find_next_bit(const unsigned long *addr1, unsigned long nbits, unsigned long start); @@ -35,6 +36,14 @@ unsigned long _find_next_bit_le(const unsigned long *addr, unsigned long size, unsigned long offset); #endif +static __always_inline +void check_find_bit(const unsigned long *addr) +{ +#ifdef CONFIG_DEBUG_BITMAP + WARN_ON_ONCE(!IS_ALIGNED((unsigned long)addr, sizeof(unsigned long))); +#endif +} + #ifndef find_next_bit /** * find_next_bit - find the next set bit in a memory region @@ -49,6 +58,8 @@ static inline unsigned long find_next_bit(const unsigned long *addr, unsigned long size, unsigned long offset) { + check_find_bit(addr); + if (small_const_nbits(size)) { unsigned long val; @@ -79,6 +90,9 @@ unsigned long find_next_and_bit(const unsigned long *addr1, const unsigned long *addr2, unsigned long size, unsigned long offset) { + check_find_bit(addr1); + check_find_bit(addr2); + if (small_const_nbits(size)) { unsigned long val; @@ -138,6 +152,8 @@ static inline unsigned long find_next_zero_bit(const unsigned long *addr, unsigned long size, unsigned long offset) { + check_find_bit(addr); + if (small_const_nbits(size)) { unsigned long val; @@ -164,6 +180,8 @@ unsigned long find_next_zero_bit(const unsigned long *addr, unsigned long size, static inline unsigned long find_first_bit(const unsigned long *addr, unsigned long size) { + check_find_bit(addr); + if (small_const_nbits(size)) { unsigned long val = *addr & GENMASK(size - 1, 0); @@ -270,6 +288,9 @@ unsigned long find_first_and_bit(const unsigned long *addr1, const unsigned long *addr2, unsigned long size) { + check_find_bit(addr1); + check_find_bit(addr2); + if (small_const_nbits(size)) { unsigned long val = *addr1 & *addr2 & GENMASK(size - 1, 0); @@ -292,6 +313,8 @@ unsigned long find_first_and_bit(const unsigned long *addr1, static inline unsigned long find_first_zero_bit(const unsigned long *addr, unsigned long size) { + check_find_bit(addr); + if (small_const_nbits(size)) { unsigned long val = *addr | ~GENMASK(size - 1, 0); @@ -313,6 +336,8 @@ unsigned long find_first_zero_bit(const unsigned long *addr, unsigned long size) static inline unsigned long find_last_bit(const unsigned long *addr, unsigned long size) { + check_find_bit(addr); + if (small_const_nbits(size)) { unsigned long val = *addr & GENMASK(size - 1, 0); @@ -417,18 +442,24 @@ extern unsigned long find_next_clump8(unsigned long *clump, static inline unsigned long find_next_zero_bit_le(const void *addr, unsigned long size, unsigned long offset) { + check_find_bit(addr); + return find_next_zero_bit(addr, size, offset); } static inline unsigned long find_next_bit_le(const void *addr, unsigned long size, unsigned long offset) { + check_find_bit(addr); + return find_next_bit(addr, size, offset); } static inline unsigned long find_first_zero_bit_le(const void *addr, unsigned long size) { + check_find_bit(addr); + return find_first_zero_bit(addr, size); } @@ -439,6 +470,8 @@ static inline unsigned long find_next_zero_bit_le(const void *addr, unsigned long size, unsigned long offset) { + check_find_bit(addr); + if (small_const_nbits(size)) { unsigned long val = *(const unsigned long *)addr; @@ -472,6 +505,8 @@ static inline unsigned long find_next_bit_le(const void *addr, unsigned long size, unsigned long offset) { + check_find_bit(addr); + if (small_const_nbits(size)) { unsigned long val = *(const unsigned long *)addr; diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug index 3fc7abffc7aa..1c7dcd33fc2a 100644 --- a/lib/Kconfig.debug +++ b/lib/Kconfig.debug @@ -543,6 +543,13 @@ endmenu # "Compiler options" menu "Generic Kernel Debugging Instruments" +config DEBUG_BITMAP + bool "Debug bitmaps" + help + Say Y here if you want to check bitmap functions parameters at + the runtime. Enable CONFIG_DEBUG_BITMAP only for debugging because + it may affect performance. + config MAGIC_SYSRQ bool "Magic SysRq key" depends on !UML