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 A8E23C63797 for ; Tue, 31 Jan 2023 00:25:12 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229757AbjAaAZL (ORCPT ); Mon, 30 Jan 2023 19:25:11 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:55686 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229839AbjAaAY7 (ORCPT ); Mon, 30 Jan 2023 19:24:59 -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 C9AFCEFAF for ; Mon, 30 Jan 2023 16:24:57 -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 68DC8B8188E for ; Tue, 31 Jan 2023 00:24:57 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 14012C433EF; Tue, 31 Jan 2023 00:24:56 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1675124696; bh=4zMiKkz/GMC73P1zoJBM70mZ8t8FAIXGJ8CT9UhMYKY=; h=Date:To:From:Subject:From; b=Sk/JIkxlavKcg/OD+7reUw7WtHOwmj/KfcGQk82m2OLqEWEfqDIvlvIIfmlCuCyew SFGHDwQGa152d6du564oW/MH8BurbEXxs5eUXpx7ujdhBxZLW1Zmkg1bl/Gh3WRd7Z h7U3oK/RoR7jPL/xSKj7jsnQHiZGpIqq1co3TPBA= Date: Mon, 30 Jan 2023 16:24:55 -0800 To: mm-commits@vger.kernel.org, vbabka@suse.cz, glider@google.com, eugenis@google.com, elver@google.com, andreyknvl@google.com, akpm@linux-foundation.org From: Andrew Morton Subject: + lib-stackdepot-move-documentation-comments-to-stackdepoth.patch added to mm-nonmm-unstable branch Message-Id: <20230131002456.14012C433EF@smtp.kernel.org> Precedence: bulk Reply-To: linux-kernel@vger.kernel.org List-ID: X-Mailing-List: mm-commits@vger.kernel.org The patch titled Subject: lib/stackdepot: move documentation comments to stackdepot.h has been added to the -mm mm-nonmm-unstable branch. Its filename is lib-stackdepot-move-documentation-comments-to-stackdepoth.patch This patch will shortly appear at https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/lib-stackdepot-move-documentation-comments-to-stackdepoth.patch This patch will later appear in the mm-nonmm-unstable branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Before you just go and hit "reply", please: a) Consider who else should be cc'ed b) Prefer to cc a suitable mailing list as well c) Ideally: find the original patch on the mailing list and do a reply-to-all to that, adding suitable additional cc's *** Remember to use Documentation/process/submit-checklist.rst when testing your code *** The -mm tree is included into linux-next via the mm-everything branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm and is updated there every 2-3 working days ------------------------------------------------------ From: Andrey Konovalov Subject: lib/stackdepot: move documentation comments to stackdepot.h Date: Mon, 30 Jan 2023 21:49:42 +0100 Move all interface- and usage-related documentation comments to include/linux/stackdepot.h. It makes sense to have them in the header where they are available to the interface users. Link: https://lkml.kernel.org/r/341353394ec1134c5a92a2b298348ddc4c48c8a0.1675111415.git.andreyknvl@google.com Signed-off-by: Andrey Konovalov Cc: Alexander Potapenko Cc: Evgenii Stepanov Cc: Marco Elver Cc: Vlastimil Babka Signed-off-by: Andrew Morton --- --- a/include/linux/stackdepot.h~lib-stackdepot-move-documentation-comments-to-stackdepoth +++ a/include/linux/stackdepot.h @@ -2,6 +2,17 @@ /* * Stack depot - a stack trace storage that avoids duplication. * + * Stack depot is intended to be used by subsystems that need to store and + * later retrieve many potentially duplicated stack traces without wasting + * memory. + * + * For example, KASAN needs to save allocation and free stack traces for each + * object. Storing two stack traces per object requires a lot of memory (e.g. + * SLUB_DEBUG needs 256 bytes per object for that). Since allocation and free + * stack traces often repeat, using stack depot allows to save about 100x space. + * + * Stack traces are never removed from stack depot. + * * Author: Alexander Potapenko * Copyright (C) 2016 Google, Inc. * @@ -57,24 +68,100 @@ static inline void stack_depot_request_e static inline int stack_depot_early_init(void) { return 0; } #endif +/** + * __stack_depot_save - Save a stack trace to stack depot + * + * @entries: Pointer to the stack trace + * @nr_entries: Number of frames in the stack + * @alloc_flags: Allocation GFP flags + * @can_alloc: Allocate stack slabs (increased chance of failure if false) + * + * Saves a stack trace from @entries array of size @nr_entries. If @can_alloc is + * %true, stack depot can replenish the stack slab pool in case no space is left + * (allocates using GFP flags of @alloc_flags). If @can_alloc is %false, avoids + * any allocations and fails if no space is left to store the stack trace. + * + * If the provided stack trace comes from the interrupt context, only the part + * up to the interrupt entry is saved. + * + * Context: Any context, but setting @can_alloc to %false is required if + * alloc_pages() cannot be used from the current context. Currently + * this is the case for contexts where neither %GFP_ATOMIC nor + * %GFP_NOWAIT can be used (NMI, raw_spin_lock). + * + * Return: Handle of the stack struct stored in depot, 0 on failure + */ depot_stack_handle_t __stack_depot_save(unsigned long *entries, unsigned int nr_entries, gfp_t gfp_flags, bool can_alloc); +/** + * stack_depot_save - Save a stack trace to stack depot + * + * @entries: Pointer to the stack trace + * @nr_entries: Number of frames in the stack + * @alloc_flags: Allocation GFP flags + * + * Context: Contexts where allocations via alloc_pages() are allowed. + * See __stack_depot_save() for more details. + * + * Return: Handle of the stack trace stored in depot, 0 on failure + */ depot_stack_handle_t stack_depot_save(unsigned long *entries, unsigned int nr_entries, gfp_t gfp_flags); +/** + * stack_depot_fetch - Fetch a stack trace from stack depot + * + * @handle: Stack depot handle returned from stack_depot_save() + * @entries: Pointer to store the address of the stack trace + * + * Return: Number of frames for the fetched stack + */ unsigned int stack_depot_fetch(depot_stack_handle_t handle, unsigned long **entries); +/** + * stack_depot_print - Print a stack trace from stack depot + * + * @stack: Stack depot handle returned from stack_depot_save() + */ void stack_depot_print(depot_stack_handle_t stack); +/** + * stack_depot_snprint - Print a stack trace from stack depot into a buffer + * + * @handle: Stack depot handle returned from stack_depot_save() + * @buf: Pointer to the print buffer + * @size: Size of the print buffer + * @spaces: Number of leading spaces to print + * + * Return: Number of bytes printed + */ int stack_depot_snprint(depot_stack_handle_t handle, char *buf, size_t size, int spaces); +/** + * stack_depot_set_extra_bits - Set extra bits in a stack depot handle + * + * @handle: Stack depot handle + * @extra_bits: Value to set the extra bits + * + * Return: Stack depot handle with extra bits set + * + * Stack depot handles have a few unused bits, which can be used for storing + * user-specific information. These bits are transparent to the stack depot. + */ depot_stack_handle_t stack_depot_set_extra_bits(depot_stack_handle_t handle, unsigned int extra_bits); +/** + * stack_depot_get_extra_bits - Retrieve extra bits from a stack depot handle + * + * @handle: Stack depot handle with extra bits saved + * + * Return: Extra bits retrieved from the stack depot handle + */ unsigned int stack_depot_get_extra_bits(depot_stack_handle_t handle); #endif --- a/lib/stackdepot.c~lib-stackdepot-move-documentation-comments-to-stackdepoth +++ a/lib/stackdepot.c @@ -2,21 +2,10 @@ /* * Stack depot - a stack trace storage that avoids duplication. * - * Stack depot is intended to be used by subsystems that need to store and - * later retrieve many potentially duplicated stack traces without wasting - * memory. - * - * For example, KASAN needs to save allocation and free stack traces for each - * object. Storing two stack traces per object requires a lot of memory (e.g. - * SLUB_DEBUG needs 256 bytes per object for that). Since allocation and free - * stack traces often repeat, using stack depot allows to save about 100x space. - * * Internally, stack depot maintains a hash table of unique stacktraces. The * stack traces themselves are stored contiguously one after another in a set * of separate page allocations. * - * Stack traces are never removed from stack depot. - * * Author: Alexander Potapenko * Copyright (C) 2016 Google, Inc. * @@ -348,29 +337,6 @@ static inline struct stack_record *find_ return NULL; } -/** - * __stack_depot_save - Save a stack trace to stack depot - * - * @entries: Pointer to the stack trace - * @nr_entries: Number of frames in the stack - * @alloc_flags: Allocation GFP flags - * @can_alloc: Allocate stack slabs (increased chance of failure if false) - * - * Saves a stack trace from @entries array of size @nr_entries. If @can_alloc is - * %true, stack depot can replenish the stack slab pool in case no space is left - * (allocates using GFP flags of @alloc_flags). If @can_alloc is %false, avoids - * any allocations and fails if no space is left to store the stack trace. - * - * If the provided stack trace comes from the interrupt context, only the part - * up to the interrupt entry is saved. - * - * Context: Any context, but setting @can_alloc to %false is required if - * alloc_pages() cannot be used from the current context. Currently - * this is the case for contexts where neither %GFP_ATOMIC nor - * %GFP_NOWAIT can be used (NMI, raw_spin_lock). - * - * Return: Handle of the stack struct stored in depot, 0 on failure - */ depot_stack_handle_t __stack_depot_save(unsigned long *entries, unsigned int nr_entries, gfp_t alloc_flags, bool can_alloc) @@ -466,18 +432,6 @@ fast_exit: } EXPORT_SYMBOL_GPL(__stack_depot_save); -/** - * stack_depot_save - Save a stack trace to stack depot - * - * @entries: Pointer to the stack trace - * @nr_entries: Number of frames in the stack - * @alloc_flags: Allocation GFP flags - * - * Context: Contexts where allocations via alloc_pages() are allowed. - * See __stack_depot_save() for more details. - * - * Return: Handle of the stack trace stored in depot, 0 on failure - */ depot_stack_handle_t stack_depot_save(unsigned long *entries, unsigned int nr_entries, gfp_t alloc_flags) @@ -486,14 +440,6 @@ depot_stack_handle_t stack_depot_save(un } EXPORT_SYMBOL_GPL(stack_depot_save); -/** - * stack_depot_fetch - Fetch a stack trace from stack depot - * - * @handle: Stack depot handle returned from stack_depot_save() - * @entries: Pointer to store the address of the stack trace - * - * Return: Number of frames for the fetched stack - */ unsigned int stack_depot_fetch(depot_stack_handle_t handle, unsigned long **entries) { @@ -523,11 +469,6 @@ unsigned int stack_depot_fetch(depot_sta } EXPORT_SYMBOL_GPL(stack_depot_fetch); -/** - * stack_depot_print - Print a stack trace from stack depot - * - * @stack: Stack depot handle returned from stack_depot_save() - */ void stack_depot_print(depot_stack_handle_t stack) { unsigned long *entries; @@ -539,16 +480,6 @@ void stack_depot_print(depot_stack_handl } EXPORT_SYMBOL_GPL(stack_depot_print); -/** - * stack_depot_snprint - Print a stack trace from stack depot into a buffer - * - * @handle: Stack depot handle returned from stack_depot_save() - * @buf: Pointer to the print buffer - * @size: Size of the print buffer - * @spaces: Number of leading spaces to print - * - * Return: Number of bytes printed - */ int stack_depot_snprint(depot_stack_handle_t handle, char *buf, size_t size, int spaces) { @@ -561,17 +492,6 @@ int stack_depot_snprint(depot_stack_hand } EXPORT_SYMBOL_GPL(stack_depot_snprint); -/** - * stack_depot_set_extra_bits - Set extra bits in a stack depot handle - * - * @handle: Stack depot handle - * @extra_bits: Value to set the extra bits - * - * Return: Stack depot handle with extra bits set - * - * Stack depot handles have a few unused bits, which can be used for storing - * user-specific information. These bits are transparent to the stack depot. - */ depot_stack_handle_t stack_depot_set_extra_bits(depot_stack_handle_t handle, unsigned int extra_bits) { @@ -582,13 +502,6 @@ depot_stack_handle_t stack_depot_set_ext } EXPORT_SYMBOL(stack_depot_set_extra_bits); -/** - * stack_depot_get_extra_bits - Retrieve extra bits from a stack depot handle - * - * @handle: Stack depot handle with extra bits saved - * - * Return: Extra bits retrieved from the stack depot handle - */ unsigned int stack_depot_get_extra_bits(depot_stack_handle_t handle) { union handle_parts parts = { .handle = handle }; _ Patches currently in -mm which might be from andreyknvl@google.com are kasan-reset-page-tags-properly-with-sampling.patch kasan-reset-page-tags-properly-with-sampling-v2.patch lib-stackdepot-fix-setting-next_slab_inited-in-init_stack_slab.patch lib-stackdepot-put-functions-in-logical-order.patch lib-stackdepot-use-pr_fmt-to-define-message-format.patch lib-stackdepot-mm-rename-stack_depot_want_early_init.patch lib-stackdepot-rename-stack_depot_disable.patch lib-stackdepot-annotate-init-and-early-init-functions.patch lib-stackdepot-lower-the-indentation-in-stack_depot_init.patch lib-stackdepot-reorder-and-annotate-global-variables.patch lib-stackdepot-rename-hash-table-constants-and-variables.patch lib-stackdepot-rename-init_stack_slab.patch lib-stackdepot-rename-slab-variables.patch lib-stackdepot-rename-handle-and-slab-constants.patch lib-stacktrace-drop-impossible-warn_on-for-depot_init_slab.patch lib-stackdepot-annotate-depot_init_slab-and-depot_alloc_stack.patch lib-stacktrace-kasan-kmsan-rework-extra_bits-interface.patch lib-stackdepot-annotate-racy-slab_index-accesses.patch lib-stackdepot-various-comments-clean-ups.patch lib-stackdepot-move-documentation-comments-to-stackdepoth.patch