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 mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id DE46CC433EF for ; Sun, 26 Sep 2021 23:44:06 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id BF6F861154 for ; Sun, 26 Sep 2021 23:44:06 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232346AbhIZXpm (ORCPT ); Sun, 26 Sep 2021 19:45:42 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:56608 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232304AbhIZXpg (ORCPT ); Sun, 26 Sep 2021 19:45:36 -0400 Received: from mail-pg1-x534.google.com (mail-pg1-x534.google.com [IPv6:2607:f8b0:4864:20::534]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 225E2C061575 for ; Sun, 26 Sep 2021 16:44:00 -0700 (PDT) Received: by mail-pg1-x534.google.com with SMTP id f129so16086419pgc.1 for ; Sun, 26 Sep 2021 16:44:00 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=7IgX6dL5NOEQt+/OKQBPTYq3DM8yqU22ikiRTuWFEQs=; b=iCi1KOKi0WklCCvp2FWY4GYlC2rLLIejsnGEbQv645XvjEvRLC03v/zhGtg9n7XhI5 B7SDPa7KX8ZnvOjkUBe0CCIoVYh6gTmIbz3aOJUartJx+s2v8diqqYBRmDpD9sv8nrbf 2YajJ6pOYEjoSYxPtatkIp0SsNnV5CUJlljPKsQyaMLQmnrh1OZfp3saxNV9wGOGBbb4 dkeHjdYZk8bjL3Q1v88Q7+WNv2SCd8BuohBIQP14f4TeMZc1Rek2pse0wAsz3XH+FZjZ RvGNfN2EEGMdoANBp+ep4zUR9Il8wWpwBvyFfyFk1K502jardGs8i2c2SXldKHtFjhLP FTDw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=7IgX6dL5NOEQt+/OKQBPTYq3DM8yqU22ikiRTuWFEQs=; b=f6JMVm7EbdEa7Oo5ZvppTcaz3Gk0AqutnyYKDcMJKWnfLyEw8cfsLIALKW0KyUT01J Qxx2SPjMO1gdlLh3X/oo35eE8F2PKgafmBw9yV6MCaxM0PiAKXaZ7Z1kNaiiigeeiMO0 VEh79ExCcFjrm7B4MuIoJParQWEuCR9Tsh7lY6YccVFQ/X5MIybCQsdixapJ0V3fufCP foXYlfrikULOorKq/Yly7Wgn8Y+Lyuv765DXB8IiLnURoumR1urVo2hTWPta4fVFkABl 9rOix34zfXSaTeu/dljAItm7L0HFCJWM9AAzLk2lEB/PL7OuPBobY5wBNsPc+yJDKqFT Wf9A== X-Gm-Message-State: AOAM530ljhWCF6HF3Tj3lBaoE6ToGNYwXcHGBi68nzeN0F5N9SHQfpUg IJKuZiwHIu//hj/6+P5DC/0= X-Google-Smtp-Source: ABdhPJx0ScK7+0SaPr9aLkqxWDiNKDgH66MEuAVqy1Czm2rGkTHqNSM7usqARFL9qBBrsg6IAd+PBQ== X-Received: by 2002:a63:8543:: with SMTP id u64mr13991077pgd.220.1632699839511; Sun, 26 Sep 2021 16:43:59 -0700 (PDT) Received: from sc2-haas01-esx0118.eng.vmware.com ([66.170.99.1]) by smtp.gmail.com with ESMTPSA id n22sm16783686pgc.55.2021.09.26.16.43.58 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Sun, 26 Sep 2021 16:43:59 -0700 (PDT) From: Nadav Amit X-Google-Original-From: Nadav Amit To: Andrew Morton Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, Peter Xu , Nadav Amit , Andrea Arcangeli , Minchan Kim , Colin Cross , Suren Baghdasarya , Mike Rapoport Subject: [RFC PATCH 4/8] mm/madvise: define madvise behavior in a struct Date: Sun, 26 Sep 2021 09:12:55 -0700 Message-Id: <20210926161259.238054-5-namit@vmware.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20210926161259.238054-1-namit@vmware.com> References: <20210926161259.238054-1-namit@vmware.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Nadav Amit The different behaviors of madvise are different in several ways, which are distributed across several functions. Use the design pattern from iouring in order to define the actions that are required for each behavior. The next patches will get rid of old helper functions that are modified in this patch and the redundant use of array_index_nospec(). The next patches will add more actions for each leaf into the new struct. No functional change is intended. Cc: Andrea Arcangeli Cc: Andrew Morton Cc: Minchan Kim Cc: Colin Cross Cc: Suren Baghdasarya Cc: Mike Rapoport Signed-off-by: Nadav Amit --- mm/madvise.c | 168 +++++++++++++++++++++++++++++++++------------------ 1 file changed, 109 insertions(+), 59 deletions(-) diff --git a/mm/madvise.c b/mm/madvise.c index 17e39c70704b..127507c71ba9 100644 --- a/mm/madvise.c +++ b/mm/madvise.c @@ -29,6 +29,7 @@ #include #include #include +#include #include @@ -39,6 +40,101 @@ struct madvise_walk_private { bool pageout; }; +struct madvise_info { + u8 behavior_valid: 1; + u8 process_behavior_valid: 1; + u8 need_mmap_read_only: 1; +}; + +static const struct madvise_info madvise_info[MADV_SOFT_OFFLINE+1] = { + [MADV_DOFORK] = { + .behavior_valid = 1, + }, + [MADV_DONTFORK] = { + .behavior_valid = 1, + }, + [MADV_NORMAL] = { + .behavior_valid = 1, + }, + [MADV_SEQUENTIAL] = { + .behavior_valid = 1, + }, + [MADV_RANDOM] = { + .behavior_valid = 1, + }, + [MADV_REMOVE] = { + .behavior_valid = 1, + .need_mmap_read_only = 1, + }, + [MADV_WILLNEED] = { + .behavior_valid = 1, + .process_behavior_valid = 1, + .need_mmap_read_only = 1, + }, + [MADV_DONTNEED] = { + .behavior_valid = 1, + .need_mmap_read_only = 1, + }, + [MADV_FREE] = { + .behavior_valid = 1, + .need_mmap_read_only = 1, + }, + [MADV_COLD] = { + .behavior_valid = 1, + .process_behavior_valid = 1, + .need_mmap_read_only = 1, + }, + [MADV_PAGEOUT] = { + .behavior_valid = 1, + .process_behavior_valid = 1, + .need_mmap_read_only = 1, + }, +#ifdef CONFIG_KSM + [MADV_MERGEABLE] = { + .behavior_valid = 1, + }, + [MADV_UNMERGEABLE] = { + .behavior_valid = 1, + }, +#endif +#ifdef CONFIG_TRANSPARENT_HUGEPAGE + [MADV_HUGEPAGE] = { + .behavior_valid = 1, + }, + [MADV_NOHUGEPAGE] = { + .behavior_valid = 1, + }, +#endif + [MADV_DONTDUMP] = { + .behavior_valid = 1, + }, + [MADV_DODUMP] = { + .behavior_valid = 1, + }, + [MADV_WIPEONFORK] = { + .behavior_valid = 1, + }, + [MADV_KEEPONFORK] = { + .behavior_valid = 1, + }, +#ifdef CONFIG_MEMORY_FAILURE + [MADV_HWPOISON] = { + .behavior_valid = 1, + }, + [MADV_SOFT_OFFLINE] = { + .behavior_valid = 1, + }, +#endif + [MADV_POPULATE_READ] = { + .behavior_valid = 1, + .need_mmap_read_only = 1, + }, + [MADV_POPULATE_WRITE] = { + .behavior_valid = 1, + .need_mmap_read_only = 1, + }, +}; + /* * Any behaviour which results in changes to the vma->vm_flags needs to * take mmap_lock for writing. Others, which simply traverse vmas, need @@ -46,20 +142,7 @@ struct madvise_walk_private { */ static int madvise_need_mmap_write(int behavior) { - switch (behavior) { - case MADV_REMOVE: - case MADV_WILLNEED: - case MADV_DONTNEED: - case MADV_COLD: - case MADV_PAGEOUT: - case MADV_FREE: - case MADV_POPULATE_READ: - case MADV_POPULATE_WRITE: - return 0; - default: - /* be safe, default to 1. list exceptions explicitly */ - return 1; - } + return !madvise_info[behavior].need_mmap_read_only; } /* @@ -999,56 +1082,23 @@ madvise_vma(struct vm_area_struct *vma, struct vm_area_struct **prev, } static bool -madvise_behavior_valid(int behavior) +madvise_behavior_valid(int *behavior) { - switch (behavior) { - case MADV_DOFORK: - case MADV_DONTFORK: - case MADV_NORMAL: - case MADV_SEQUENTIAL: - case MADV_RANDOM: - case MADV_REMOVE: - case MADV_WILLNEED: - case MADV_DONTNEED: - case MADV_FREE: - case MADV_COLD: - case MADV_PAGEOUT: - case MADV_POPULATE_READ: - case MADV_POPULATE_WRITE: -#ifdef CONFIG_KSM - case MADV_MERGEABLE: - case MADV_UNMERGEABLE: -#endif -#ifdef CONFIG_TRANSPARENT_HUGEPAGE - case MADV_HUGEPAGE: - case MADV_NOHUGEPAGE: -#endif - case MADV_DONTDUMP: - case MADV_DODUMP: - case MADV_WIPEONFORK: - case MADV_KEEPONFORK: -#ifdef CONFIG_MEMORY_FAILURE - case MADV_SOFT_OFFLINE: - case MADV_HWPOISON: -#endif - return true; - - default: + if (*behavior >= ARRAY_SIZE(madvise_info)) return false; - } + + *behavior = array_index_nospec(*behavior, ARRAY_SIZE(madvise_info)); + return madvise_info[*behavior].behavior_valid; } static bool -process_madvise_behavior_valid(int behavior) +process_madvise_behavior_valid(int *behavior) { - switch (behavior) { - case MADV_COLD: - case MADV_PAGEOUT: - case MADV_WILLNEED: - return true; - default: + if (*behavior >= ARRAY_SIZE(madvise_info)) return false; - } + + *behavior = array_index_nospec(*behavior, ARRAY_SIZE(madvise_info)); + return madvise_info[*behavior].process_behavior_valid; } /* @@ -1133,7 +1183,7 @@ int do_madvise(struct mm_struct *mm, unsigned long start, size_t len_in, int beh start = untagged_addr(start); - if (!madvise_behavior_valid(behavior)) + if (!madvise_behavior_valid(&behavior)) return error; if (!PAGE_ALIGNED(start)) @@ -1258,7 +1308,7 @@ SYSCALL_DEFINE5(process_madvise, int, pidfd, const struct iovec __user *, vec, goto put_pid; } - if (!process_madvise_behavior_valid(behavior)) { + if (!process_madvise_behavior_valid(&behavior)) { ret = -EINVAL; goto release_task; } -- 2.25.1