From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-20.4 required=3.0 tests=BAYES_00,DKIMWL_WL_MED, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_GIT,USER_IN_DEF_DKIM_WL autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id B72FDC433DF for ; Mon, 12 Oct 2020 20:47:18 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 555A7208D5 for ; Mon, 12 Oct 2020 20:47:18 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="P2R3KXtk" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729557AbgJLUrH (ORCPT ); Mon, 12 Oct 2020 16:47:07 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:40938 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1731439AbgJLUqq (ORCPT ); Mon, 12 Oct 2020 16:46:46 -0400 Received: from mail-ej1-x649.google.com (mail-ej1-x649.google.com [IPv6:2a00:1450:4864:20::649]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id D5A9CC0613D7 for ; Mon, 12 Oct 2020 13:46:03 -0700 (PDT) Received: by mail-ej1-x649.google.com with SMTP id k13so6772042ejv.16 for ; Mon, 12 Oct 2020 13:46:03 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=sender:date:in-reply-to:message-id:mime-version:references:subject :from:to:cc; bh=FxkgJWitnYQ4KCO5g1pFJrvXiUx3cakvbVWfbN/gwfM=; b=P2R3KXtk+miPGtCQ/ftFngtqpBO1fCTFodZE+2pqsiYQkXvzJUcMgDh3tmmVLtCZMw OcH56KV/uiefEuYUt+YsxjrSUSiNfco9ED6dq1InxgWFmCvQwDLvOEcWV7Vcchdv4wtp MG74gOCnRdz6bdJaPrY2tFBnMsCVAGQVn/lkHPlg1lkFEzYP467zbTqkwFUrQOZ0HWoG oR0OAHfkwPraMOim4LeiSn4F2qmJkwo5YBtWiagitgDVCoJr1sMltcMGOD0y1nALOUBo wmPEDj1/e3jfhrL4myn9POr2H/6ueC0yFeEfF9rRw50xPVRxQPOzVuFzn5yGWUR+kX9d c1Dg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:sender:date:in-reply-to:message-id:mime-version :references:subject:from:to:cc; bh=FxkgJWitnYQ4KCO5g1pFJrvXiUx3cakvbVWfbN/gwfM=; b=QkOameH0k5ZNL9e/sGPgHi9IcAsfx03vc02YPZnQUYn1aLZcRHFwEp5/HBhIKTg94D xF/OZH8NGgFccudzmXJ4BBg0inPUpqL8WQCKJGDrVpI2hieTaaGAflHaLdTSg6dE8t1y na78QX3mPHiK82f0PJcSze/Pba5jzmdD8dxdkHMlZcu7xK4f6JntKfAMU7Gt/WE1kkRF tb3umy3ci56nLx4oOuKDclJFsJ/HkfuO3kv7tSBFbpXYcp/V8+ZjNyOgkmV/oV5FMCJr 4WF8i789HrjiL2W2dHL2FhsIRv8TLahEHDCkkK/SCeRah9a64YrpKy5iJkaY6TvNzBYW 4EWw== X-Gm-Message-State: AOAM531n7agUJ3TVvkd4hlQo14XhTT52Fz2XkTCtvfxoOyerzqgbNE6e MsTvgWM6W9oWX9IRFReHX0KiBweFNq2xhdeS X-Google-Smtp-Source: ABdhPJz/BddLvNCDRFZcot/tUVN8NYq/sCHyMsbWAP6so+MT7dwjcMUH63fvAtg2uu0h61182mDeXHB+wNMa1AAT Sender: "andreyknvl via sendgmr" X-Received: from andreyknvl3.muc.corp.google.com ([2a00:79e0:15:13:7220:84ff:fe09:7e9d]) (user=andreyknvl job=sendgmr) by 2002:a50:fa89:: with SMTP id w9mr16233395edr.235.1602535562467; Mon, 12 Oct 2020 13:46:02 -0700 (PDT) Date: Mon, 12 Oct 2020 22:44:35 +0200 In-Reply-To: Message-Id: <10a1185de44bee978449f07b448ebbe52c2435e0.1602535397.git.andreyknvl@google.com> Mime-Version: 1.0 References: X-Mailer: git-send-email 2.28.0.1011.ga647a8990f-goog Subject: [PATCH v5 29/40] kasan: separate metadata_fetch_row for each mode From: Andrey Konovalov To: Catalin Marinas , Will Deacon Cc: Vincenzo Frascino , kasan-dev@googlegroups.com, Dmitry Vyukov , Andrey Ryabinin , Alexander Potapenko , Marco Elver , Evgenii Stepanov , Elena Petrova , Branislav Rankov , Kevin Brodsky , Andrew Morton , linux-arm-kernel@lists.infradead.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org, Andrey Konovalov Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org This is a preparatory commit for the upcoming addition of a new hardware tag-based (MTE-based) KASAN mode. Rework print_memory_metadata() to make it agnostic with regard to the way metadata is stored. Allow providing a separate metadata_fetch_row() implementation for each KASAN mode. Hardware tag-based KASAN will provide its own implementation that doesn't use shadow memory. No functional changes for software modes. Signed-off-by: Andrey Konovalov Signed-off-by: Vincenzo Frascino Reviewed-by: Marco Elver --- Change-Id: I5b0ed1d079ea776e620beca6a529a861e7dced95 --- mm/kasan/kasan.h | 8 ++++++ mm/kasan/report.c | 56 +++++++++++++++++++-------------------- mm/kasan/report_generic.c | 5 ++++ mm/kasan/report_sw_tags.c | 5 ++++ 4 files changed, 45 insertions(+), 29 deletions(-) diff --git a/mm/kasan/kasan.h b/mm/kasan/kasan.h index 420638225c13..9c73f324e3ce 100644 --- a/mm/kasan/kasan.h +++ b/mm/kasan/kasan.h @@ -57,6 +57,13 @@ #define KASAN_ABI_VERSION 1 #endif +/* Metadata layout customization. */ +#define META_BYTES_PER_BLOCK 1 +#define META_BLOCKS_PER_ROW 16 +#define META_BYTES_PER_ROW (META_BLOCKS_PER_ROW * META_BYTES_PER_BLOCK) +#define META_MEM_BYTES_PER_ROW (META_BYTES_PER_ROW * KASAN_GRANULE_SIZE) +#define META_ROWS_AROUND_ADDR 2 + struct kasan_access_info { const void *access_addr; const void *first_bad_addr; @@ -168,6 +175,7 @@ bool check_invalid_free(void *addr); void *find_first_bad_addr(void *addr, size_t size); const char *get_bug_type(struct kasan_access_info *info); +void metadata_fetch_row(char *buffer, void *row); #ifdef CONFIG_KASAN_STACK_ENABLE void print_address_stack_frame(const void *addr); diff --git a/mm/kasan/report.c b/mm/kasan/report.c index 13b27675a696..3924127b4786 100644 --- a/mm/kasan/report.c +++ b/mm/kasan/report.c @@ -31,12 +31,6 @@ #include "kasan.h" #include "../slab.h" -/* Metadata layout customization. */ -#define META_BYTES_PER_BLOCK 1 -#define META_BLOCKS_PER_ROW 16 -#define META_BYTES_PER_ROW (META_BLOCKS_PER_ROW * META_BYTES_PER_BLOCK) -#define META_ROWS_AROUND_ADDR 2 - static unsigned long kasan_flags; #define KASAN_BIT_REPORTED 0 @@ -236,55 +230,59 @@ static void print_address_description(void *addr, u8 tag) print_address_stack_frame(addr); } -static bool row_is_guilty(const void *row, const void *guilty) +static bool meta_row_is_guilty(const void *row, const void *addr) { - return (row <= guilty) && (guilty < row + META_BYTES_PER_ROW); + return (row <= addr) && (addr < row + META_MEM_BYTES_PER_ROW); } -static int shadow_pointer_offset(const void *row, const void *shadow) +static int meta_pointer_offset(const void *row, const void *addr) { - /* The length of ">ff00ff00ff00ff00: " is - * 3 + (BITS_PER_LONG/8)*2 chars. + /* + * Memory state around the buggy address: + * ff00ff00ff00ff00: 00 00 00 05 fe fe fe fe fe fe fe fe fe fe fe fe + * ... + * + * The length of ">ff00ff00ff00ff00: " is + * 3 + (BITS_PER_LONG / 8) * 2 chars. + * The length of each granule metadata is 2 bytes + * plus 1 byte for space. */ - return 3 + (BITS_PER_LONG/8)*2 + (shadow - row)*2 + - (shadow - row) / META_BYTES_PER_BLOCK + 1; + return 3 + (BITS_PER_LONG / 8) * 2 + + (addr - row) / KASAN_GRANULE_SIZE * 3 + 1; } static void print_memory_metadata(const void *addr) { int i; - const void *shadow = kasan_mem_to_shadow(addr); - const void *shadow_row; + void *row; - shadow_row = (void *)round_down((unsigned long)shadow, - META_BYTES_PER_ROW) - - META_ROWS_AROUND_ADDR * META_BYTES_PER_ROW; + row = (void *)round_down((unsigned long)addr, META_MEM_BYTES_PER_ROW) + - META_ROWS_AROUND_ADDR * META_MEM_BYTES_PER_ROW; pr_err("Memory state around the buggy address:\n"); for (i = -META_ROWS_AROUND_ADDR; i <= META_ROWS_AROUND_ADDR; i++) { - const void *kaddr = kasan_shadow_to_mem(shadow_row); - char buffer[4 + (BITS_PER_LONG/8)*2]; - char shadow_buf[META_BYTES_PER_ROW]; + char buffer[4 + (BITS_PER_LONG / 8) * 2]; + char metadata[META_BYTES_PER_ROW]; snprintf(buffer, sizeof(buffer), - (i == 0) ? ">%px: " : " %px: ", kaddr); + (i == 0) ? ">%px: " : " %px: ", row); + /* * We should not pass a shadow pointer to generic * function, because generic functions may try to * access kasan mapping for the passed address. */ - memcpy(shadow_buf, shadow_row, META_BYTES_PER_ROW); + metadata_fetch_row(&metadata[0], row); + print_hex_dump(KERN_ERR, buffer, DUMP_PREFIX_NONE, META_BYTES_PER_ROW, 1, - shadow_buf, META_BYTES_PER_ROW, 0); + metadata, META_BYTES_PER_ROW, 0); - if (row_is_guilty(shadow_row, shadow)) - pr_err("%*c\n", - shadow_pointer_offset(shadow_row, shadow), - '^'); + if (meta_row_is_guilty(row, addr)) + pr_err("%*c\n", meta_pointer_offset(row, addr), '^'); - shadow_row += META_BYTES_PER_ROW; + row += META_MEM_BYTES_PER_ROW; } } diff --git a/mm/kasan/report_generic.c b/mm/kasan/report_generic.c index ff067071cd28..de7a85c83106 100644 --- a/mm/kasan/report_generic.c +++ b/mm/kasan/report_generic.c @@ -122,6 +122,11 @@ const char *get_bug_type(struct kasan_access_info *info) return get_wild_bug_type(info); } +void metadata_fetch_row(char *buffer, void *row) +{ + memcpy(buffer, kasan_mem_to_shadow(row), META_BYTES_PER_ROW); +} + #ifdef CONFIG_KASAN_STACK_ENABLE static bool __must_check tokenize_frame_descr(const char **frame_descr, char *token, size_t max_tok_len, diff --git a/mm/kasan/report_sw_tags.c b/mm/kasan/report_sw_tags.c index c87d5a343b4e..add2dfe6169c 100644 --- a/mm/kasan/report_sw_tags.c +++ b/mm/kasan/report_sw_tags.c @@ -80,6 +80,11 @@ void *find_first_bad_addr(void *addr, size_t size) return p; } +void metadata_fetch_row(char *buffer, void *row) +{ + memcpy(buffer, kasan_mem_to_shadow(row), META_BYTES_PER_ROW); +} + void print_tags(u8 addr_tag, const void *addr) { u8 *shadow = (u8 *)kasan_mem_to_shadow(addr); -- 2.28.0.1011.ga647a8990f-goog