From patchwork Mon Jan 30 20:49:30 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: andrey.konovalov@linux.dev X-Patchwork-Id: 13121820 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 kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id 28A6AC63797 for ; Mon, 30 Jan 2023 20:50:59 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id A1FD26B0078; Mon, 30 Jan 2023 15:50:56 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 890186B0082; Mon, 30 Jan 2023 15:50:56 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 5371B6B0078; Mon, 30 Jan 2023 15:50:56 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0013.hostedemail.com [216.40.44.13]) by kanga.kvack.org (Postfix) with ESMTP id 3FF896B0075 for ; Mon, 30 Jan 2023 15:50:56 -0500 (EST) Received: from smtpin29.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay10.hostedemail.com (Postfix) with ESMTP id 2425AC0B98 for ; Mon, 30 Jan 2023 20:50:56 +0000 (UTC) X-FDA: 80412659712.29.99CB872 Received: from out-87.mta0.migadu.com (out-87.mta0.migadu.com [91.218.175.87]) by imf01.hostedemail.com (Postfix) with ESMTP id 665594000E for ; Mon, 30 Jan 2023 20:50:53 +0000 (UTC) Authentication-Results: imf01.hostedemail.com; dkim=pass header.d=linux.dev header.s=key1 header.b="qTAqH/h3"; spf=pass (imf01.hostedemail.com: domain of andrey.konovalov@linux.dev designates 91.218.175.87 as permitted sender) smtp.mailfrom=andrey.konovalov@linux.dev; dmarc=pass (policy=none) header.from=linux.dev ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1675111853; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=TXUvy5WDZhr7BlKZ84VBiDQ9FKi0bXR5FVmrmN5uemo=; b=Wq35vyI/i5C+LYwMbMFf8l2yCEtbbqBAeee4aW0aWsOOwuINf3Pz3TVPJsbtAjwEa1DN03 5JtnmAwJCzuk8oJ2oUM95+DT46rLc/Yx47BDycf506MInQvIb3P3eTntNSNLtHl3Kv0/QI /D2WSpASHZbd7TXJ7Y9ueUd8vL1Am5g= ARC-Authentication-Results: i=1; imf01.hostedemail.com; dkim=pass header.d=linux.dev header.s=key1 header.b="qTAqH/h3"; spf=pass (imf01.hostedemail.com: domain of andrey.konovalov@linux.dev designates 91.218.175.87 as permitted sender) smtp.mailfrom=andrey.konovalov@linux.dev; dmarc=pass (policy=none) header.from=linux.dev ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1675111853; a=rsa-sha256; cv=none; b=h7DM8Hamc+ayT1NKwhgDqUFzodnT0ps5PWmUN1JBSYQNsRAr2uknAFScL4det4bG3KMfgR SBUW4ctl4I3WkzUZjaBk867ZHHg+gvJdgyLbfuRj6P7JHzMwnhJWkeOnCzR6Kqjk26FCLe JPnl+XJhcCC2u8MTEaGGUl9GsNCWi68= X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1675111851; 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=TXUvy5WDZhr7BlKZ84VBiDQ9FKi0bXR5FVmrmN5uemo=; b=qTAqH/h3lvp3LBinh9ZgKXdhYP02imBJEuB8uqH1iUms1FkvE7RqMS6kgwiVfxPo6dPFiZ INjsSD6+m11nC0jZlXtAXeRY8JnQiDDTw74kkvq8iy8WIY5f1IjA3puf+2wSsDQv7yH1KS kCzz9lKkR7o1ZLchiqq6nGUmdZMJN3g= From: andrey.konovalov@linux.dev To: Marco Elver , Alexander Potapenko Cc: Andrey Konovalov , Vlastimil Babka , kasan-dev@googlegroups.com, Evgenii Stepanov , Andrew Morton , linux-mm@kvack.org, linux-kernel@vger.kernel.org, Andrey Konovalov Subject: [PATCH 06/18] lib/stackdepot: annotate init and early init functions Date: Mon, 30 Jan 2023 21:49:30 +0100 Message-Id: In-Reply-To: References: MIME-Version: 1.0 X-Migadu-Flow: FLOW_OUT X-Stat-Signature: hh3hit4hbiwg6eu44j7pdxrfwo8z41kw X-Rspam-User: X-Rspamd-Queue-Id: 665594000E X-Rspamd-Server: rspam06 X-HE-Tag: 1675111853-871900 X-HE-Meta: U2FsdGVkX1/OI3KioJNmw3BI5i7+bflAc5OEv1b0nFUndMBcQTnvMP8KDSW04GwbJ7wvvk2FQdyyeDSsYQMZWJIMquJdsihVdJK9vk193ociWi0vMdAhotEZuZt4Mpu+RiW+uReQrcwibtJg5fV/9Hn0iZXVY+IdWvX8T5t5QopZlbKyQlX3olKpDITxCmap2DMI/BpwguuSGIMq43usPiw3BJ5hPOokn+D8BGU/vWGRcXq/0YrvyQfJqQhOTDa5yTsHaXBJnKyTp7WBke7uFgugqFS5TBNiVvpAsFyFWJ4g6fsFGP0fWnwI/zWPb7+QMqxCtusErcJwQp7LxaE8IB8vv9VHFi1nWfUrNtEaqo5MQnWCfoTGVx5/qykv1WZPAxglI9/u4PU4OtEokUJoLKdS//jobR/bMQcXKtnxlC5x4xECEtsbe/dpOZFRS9g9eQ7yRAQgJj8oWka4LxanLMeV4iWZBAowXb7PeGwc7rOE8D1ukJRc2xkxr0RUiNbshAYpOhmV84V7TS52L9G0VTy81KVrxACG7QUioj47coKFuyFfd+bDn4r5vTSSMK73rbX26x1UkKs/SqBeJthf2TT4vVQkoeqDTtGLdog8ASFXxDdKAEhWxgq5yhBzoYL1yC+5+azUYCUkzqsdyQ7+0Ep+efLcKBNF7wXFOzwtZlKOZyP85lDIRIxIGQlYMK3pdvA12PuJMWP9fF9TPyCBb706u8YpKtVfE0VRL0vSMtOhb6od+mYOyw5ctyTxrwPzvN2cGGbuOm2RwEFzs8yb/xhkL6QIxPu7EKMK4G2/21Sc8dbQ8A3ZxjWlDkCMlUZ2iC+pxia75Be55GDVXQkdrLc/sx3AoY8g7PDSOndWor4Tw9phzFj1fXRhCD98CeQc8qta/cqBrz3ZVbGfHf5U+kuMVO618PmbS6kDVgJ3FPWCs7DGgWzXE/mBR6wV4bcqcpDYoSWqylK4evUwh1O 4Zp/QmHR +QYHjLkzxpESmJqCeMPjtKIx2494K77IvO/Di9wmM5LSk+IwNO/NZwu+Xoph80IL4nUPPb8NTyjMfsiLjdkfHChLt/Ynt16HOnpdS X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: From: Andrey Konovalov Add comments to stack_depot_early_init and stack_depot_init to explain certain parts of their implementation. Also add a pr_info message to stack_depot_early_init similar to the one in stack_depot_init. Also move the scale variable in stack_depot_init to the scope where it is being used. Signed-off-by: Andrey Konovalov Reviewed-by: Alexander Potapenko --- lib/stackdepot.c | 27 +++++++++++++++++++++------ 1 file changed, 21 insertions(+), 6 deletions(-) diff --git a/lib/stackdepot.c b/lib/stackdepot.c index 6e8aef12cf89..b06f6a5caa83 100644 --- a/lib/stackdepot.c +++ b/lib/stackdepot.c @@ -115,24 +115,34 @@ void __init stack_depot_request_early_init(void) __stack_depot_early_init_requested = true; } +/* Allocates a hash table via memblock. Can only be used during early boot. */ int __init stack_depot_early_init(void) { unsigned long entries = 0; - /* This is supposed to be called only once, from mm_init() */ + /* This function must be called only once, from mm_init(). */ if (WARN_ON(__stack_depot_early_init_passed)) return 0; - __stack_depot_early_init_passed = true; + /* + * If KASAN is enabled, use the maximum order: KASAN is frequently used + * in fuzzing scenarios, which leads to a large number of different + * stack traces being stored in stack depot. + */ if (kasan_enabled() && !stack_hash_order) stack_hash_order = STACK_HASH_ORDER_MAX; if (!__stack_depot_early_init_requested || stack_depot_disabled) return 0; + /* + * If stack_hash_order is not set, leave entries as 0 to rely on the + * automatic calculations performed by alloc_large_system_hash. + */ if (stack_hash_order) - entries = 1UL << stack_hash_order; + entries = 1UL << stack_hash_order; + pr_info("allocating hash table via alloc_large_system_hash\n"); stack_table = alloc_large_system_hash("stackdepot", sizeof(struct stack_record *), entries, @@ -142,7 +152,6 @@ int __init stack_depot_early_init(void) &stack_hash_mask, 1UL << STACK_HASH_ORDER_MIN, 1UL << STACK_HASH_ORDER_MAX); - if (!stack_table) { pr_err("hash table allocation failed, disabling\n"); stack_depot_disabled = true; @@ -152,6 +161,7 @@ int __init stack_depot_early_init(void) return 0; } +/* Allocates a hash table via kvmalloc. Can be used after boot. */ int stack_depot_init(void) { static DEFINE_MUTEX(stack_depot_init_mutex); @@ -160,11 +170,16 @@ int stack_depot_init(void) mutex_lock(&stack_depot_init_mutex); if (!stack_depot_disabled && !stack_table) { unsigned long entries; - int scale = STACK_HASH_SCALE; + /* + * Similarly to stack_depot_early_init, use stack_hash_order + * if assigned, and rely on automatic scaling otherwise. + */ if (stack_hash_order) { entries = 1UL << stack_hash_order; } else { + int scale = STACK_HASH_SCALE; + entries = nr_free_buffer_pages(); entries = roundup_pow_of_two(entries); @@ -179,7 +194,7 @@ int stack_depot_init(void) if (entries > 1UL << STACK_HASH_ORDER_MAX) entries = 1UL << STACK_HASH_ORDER_MAX; - pr_info("allocating hash table of %lu entries with kvcalloc\n", + pr_info("allocating hash table of %lu entries via kvcalloc\n", entries); stack_table = kvcalloc(entries, sizeof(struct stack_record *), GFP_KERNEL); if (!stack_table) {