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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id DF392C4332F for ; Mon, 3 Oct 2022 21:10:30 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229696AbiJCVK2 (ORCPT ); Mon, 3 Oct 2022 17:10:28 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:49474 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229711AbiJCVI0 (ORCPT ); Mon, 3 Oct 2022 17:08:26 -0400 Received: from ams.source.kernel.org (ams.source.kernel.org [IPv6:2604:1380:4601:e00::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 82C1C4F1BB for ; Mon, 3 Oct 2022 14:06:27 -0700 (PDT) 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 C71D7B81122 for ; Mon, 3 Oct 2022 21:06:25 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 63CB7C433D7; Mon, 3 Oct 2022 21:06:24 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1664831184; bh=xXQJinIpGO8wMnQsSz5vMJP/0DkP2ovYVURTYsstDzA=; h=Date:To:From:Subject:From; b=qRAC67Z6K3hN1IXoj8s+cHN7LynTCEdHgOqNchVU9AVrbpjiZCrXtX3Db3e/ncDYA CbTzPTO3lPxlTQOVCkXdMG1o1BwfTgGvdQMdx94VfxIIdIoJM3HL2BZrB4MnOXcUTB /asnKk5C7X2if4kfCTPc5gb0B7iwgJjx4yMiHQsk= Date: Mon, 03 Oct 2022 14:06:23 -0700 To: mm-commits@vger.kernel.org, ryabinin.a.a@gmail.com, pcc@google.com, glider@google.com, eugenis@google.com, elver@google.com, dvyukov@google.com, andreyknvl@google.com, akpm@linux-foundation.org From: Andrew Morton Subject: [merged mm-stable] kasan-dynamically-allocate-stack-ring-entries.patch removed from -mm tree Message-Id: <20221003210624.63CB7C433D7@smtp.kernel.org> Precedence: bulk Reply-To: linux-kernel@vger.kernel.org List-ID: X-Mailing-List: mm-commits@vger.kernel.org The quilt patch titled Subject: kasan: dynamically allocate stack ring entries has been removed from the -mm tree. Its filename was kasan-dynamically-allocate-stack-ring-entries.patch This patch was dropped because it was merged into the mm-stable branch of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm ------------------------------------------------------ From: Andrey Konovalov Subject: kasan: dynamically allocate stack ring entries Date: Mon, 5 Sep 2022 23:05:47 +0200 Instead of using a large static array, allocate the stack ring dynamically via memblock_alloc(). The size of the stack ring is controlled by a new kasan.stack_ring_size command-line parameter. When kasan.stack_ring_size is not provided, the default value of 32 << 10 is used. When the stack trace collection is disabled via kasan.stacktrace=off, the stack ring is not allocated. Link: https://lkml.kernel.org/r/03b82ab60db53427e9818e0b0c1971baa10c3cbc.1662411800.git.andreyknvl@google.com Signed-off-by: Andrey Konovalov Acked-by: Marco Elver Cc: Alexander Potapenko Cc: Andrey Ryabinin Cc: Dmitry Vyukov Cc: Evgenii Stepanov Cc: Peter Collingbourne Signed-off-by: Andrew Morton --- Documentation/dev-tools/kasan.rst | 4 +++- mm/kasan/kasan.h | 5 ++--- mm/kasan/report_tags.c | 4 ++-- mm/kasan/tags.c | 25 ++++++++++++++++++++++++- 4 files changed, 31 insertions(+), 7 deletions(-) --- a/Documentation/dev-tools/kasan.rst~kasan-dynamically-allocate-stack-ring-entries +++ a/Documentation/dev-tools/kasan.rst @@ -112,10 +112,12 @@ parameter can be used to control panic a if ``kasan_multi_shot`` is enabled. Software and Hardware Tag-Based KASAN modes (see the section about various -modes below) support disabling stack trace collection: +modes below) support altering stack trace collection behavior: - ``kasan.stacktrace=off`` or ``=on`` disables or enables alloc and free stack traces collection (default: ``on``). +- ``kasan.stack_ring_size=`` specifies the number of entries + in the stack ring (default: ``32768``). Hardware Tag-Based KASAN mode is intended for use in production as a security mitigation. Therefore, it supports additional boot parameters that allow --- a/mm/kasan/kasan.h~kasan-dynamically-allocate-stack-ring-entries +++ a/mm/kasan/kasan.h @@ -252,12 +252,11 @@ struct kasan_stack_ring_entry { bool is_free; }; -#define KASAN_STACK_RING_SIZE (32 << 10) - struct kasan_stack_ring { rwlock_t lock; + size_t size; atomic64_t pos; - struct kasan_stack_ring_entry entries[KASAN_STACK_RING_SIZE]; + struct kasan_stack_ring_entry *entries; }; #endif /* CONFIG_KASAN_SW_TAGS || CONFIG_KASAN_HW_TAGS */ --- a/mm/kasan/report_tags.c~kasan-dynamically-allocate-stack-ring-entries +++ a/mm/kasan/report_tags.c @@ -56,11 +56,11 @@ void kasan_complete_mode_report_info(str * entries relevant to the buggy object can be overwritten. */ - for (u64 i = pos - 1; i != pos - 1 - KASAN_STACK_RING_SIZE; i--) { + for (u64 i = pos - 1; i != pos - 1 - stack_ring.size; i--) { if (alloc_found && free_found) break; - entry = &stack_ring.entries[i % KASAN_STACK_RING_SIZE]; + entry = &stack_ring.entries[i % stack_ring.size]; /* Paired with smp_store_release() in save_stack_info(). */ ptr = (void *)smp_load_acquire(&entry->ptr); --- a/mm/kasan/tags.c~kasan-dynamically-allocate-stack-ring-entries +++ a/mm/kasan/tags.c @@ -10,6 +10,7 @@ #include #include #include +#include #include #include #include @@ -19,6 +20,8 @@ #include "kasan.h" #include "../slab.h" +#define KASAN_STACK_RING_SIZE_DEFAULT (32 << 10) + enum kasan_arg_stacktrace { KASAN_ARG_STACKTRACE_DEFAULT, KASAN_ARG_STACKTRACE_OFF, @@ -54,6 +57,16 @@ static int __init early_kasan_flag_stack } early_param("kasan.stacktrace", early_kasan_flag_stacktrace); +/* kasan.stack_ring_size= */ +static int __init early_kasan_flag_stack_ring_size(char *arg) +{ + if (!arg) + return -EINVAL; + + return kstrtoul(arg, 0, &stack_ring.size); +} +early_param("kasan.stack_ring_size", early_kasan_flag_stack_ring_size); + void __init kasan_init_tags(void) { switch (kasan_arg_stacktrace) { @@ -67,6 +80,16 @@ void __init kasan_init_tags(void) static_branch_enable(&kasan_flag_stacktrace); break; } + + if (kasan_stack_collection_enabled()) { + if (!stack_ring.size) + stack_ring.size = KASAN_STACK_RING_SIZE_DEFAULT; + stack_ring.entries = memblock_alloc( + sizeof(stack_ring.entries[0]) * stack_ring.size, + SMP_CACHE_BYTES); + if (WARN_ON(!stack_ring.entries)) + static_branch_disable(&kasan_flag_stacktrace); + } } static void save_stack_info(struct kmem_cache *cache, void *object, @@ -88,7 +111,7 @@ static void save_stack_info(struct kmem_ next: pos = atomic64_fetch_add(1, &stack_ring.pos); - entry = &stack_ring.entries[pos % KASAN_STACK_RING_SIZE]; + entry = &stack_ring.entries[pos % stack_ring.size]; /* Detect stack ring entry slots that are being written to. */ old_ptr = READ_ONCE(entry->ptr); _ Patches currently in -mm which might be from andreyknvl@google.com are kasan-fix-array-bounds-warnings-in-tests.patch