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 kanga.kvack.org (kanga.kvack.org [205.233.56.17]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id A7EA6CCF9E3 for ; Mon, 10 Nov 2025 16:37:12 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 0E4DF8E003F; Mon, 10 Nov 2025 11:37:12 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 0BD0A8E0003; Mon, 10 Nov 2025 11:37:12 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id EEDAF8E003F; Mon, 10 Nov 2025 11:37:11 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0014.hostedemail.com [216.40.44.14]) by kanga.kvack.org (Postfix) with ESMTP id DDFD78E0003 for ; Mon, 10 Nov 2025 11:37:11 -0500 (EST) Received: from smtpin07.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay01.hostedemail.com (Postfix) with ESMTP id A979C1DFD41 for ; Mon, 10 Nov 2025 16:37:11 +0000 (UTC) X-FDA: 84095252262.07.07D6734 Received: from mail-pj1-f46.google.com (mail-pj1-f46.google.com [209.85.216.46]) by imf05.hostedemail.com (Postfix) with ESMTP id CF11B10000F for ; Mon, 10 Nov 2025 16:37:09 +0000 (UTC) Authentication-Results: imf05.hostedemail.com; dkim=pass header.d=gmail.com header.s=20230601 header.b=d1ZLO6ET; dmarc=pass (policy=none) header.from=gmail.com; spf=pass (imf05.hostedemail.com: domain of wangjinchao600@gmail.com designates 209.85.216.46 as permitted sender) smtp.mailfrom=wangjinchao600@gmail.com ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1762792629; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:mime-version:mime-version:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=RDpE0CvbPiS95CD/e7bDhFl1FHfdcNhWeVLe6GjR39g=; b=bxvehK4bWEIa79qLT8Tb+gztLlVGExrEwZAInHB70tH7/BxQZCvhOb0oqjqxxQ9DyKLBP9 sSz1YAl9D5T3JKbQIYzJJX0J07CrzPYk3ruSlJ0l14YmVHh34jJs7CLGxciHa1HHfK3kLB s4NAEovmk5/WxvYiXtcHpkp8z7sEU/s= ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1762792629; a=rsa-sha256; cv=none; b=PRKmhHSHzlfcvD1dk9qXwfjcokVPbpTjtX4YZps+P7kn6LlStAGgZD1hZV13y5enVrHcct AN9qG0BtacyTx1MHKFYCfl+NndlkLsYK5p2xUstTJHtuUBkQmCvBb1OIHMbfw/IshYBB6z k7fUmfPt+KpNAuJhrue/Yxo1mWvb6zQ= ARC-Authentication-Results: i=1; imf05.hostedemail.com; dkim=pass header.d=gmail.com header.s=20230601 header.b=d1ZLO6ET; dmarc=pass (policy=none) header.from=gmail.com; spf=pass (imf05.hostedemail.com: domain of wangjinchao600@gmail.com designates 209.85.216.46 as permitted sender) smtp.mailfrom=wangjinchao600@gmail.com Received: by mail-pj1-f46.google.com with SMTP id 98e67ed59e1d1-34101107cc8so2621058a91.0 for ; Mon, 10 Nov 2025 08:37:09 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20230601; t=1762792629; x=1763397429; darn=kvack.org; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:to:from:from:to:cc:subject:date:message-id :reply-to; bh=RDpE0CvbPiS95CD/e7bDhFl1FHfdcNhWeVLe6GjR39g=; b=d1ZLO6ETgL9YzVH0jdFLO0KrGXVg6ZTeBefDIXi0ZtUo4WAdAMdMAmDS2hOlo1r20K 9aq5yQstNITTvV4OpSl3fm9MXAgPQxiSBfmOjMW9SFua6QUJcmnJwawrFfVDI3iKhNOO dy6ssNMxLMDY40IQ2DNl01cXqxrq/XBihVmHlAlHcYCI5KoI/BuuJ2WwQq2DhurlpI/Q VL4IxTne4+Ewt/QvkduKD8zqmSYi3k3kPnkqJp1JFXcT3++KhZ5yEVQbWCiTQsxpGvpp uJaZrZBk47qbJr8sjIO299pOaW4WOTa8ZbE3ZQq8IziXceasrrbT8VeVvfBdI0RZ1Dq1 8ajg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1762792629; x=1763397429; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:to:from:x-gm-gg:x-gm-message-state:from:to :cc:subject:date:message-id:reply-to; bh=RDpE0CvbPiS95CD/e7bDhFl1FHfdcNhWeVLe6GjR39g=; b=bj9k0aemYOKL5L4jGkACG0vlAe+fW36g0cCEFCRxXjHwv/UYhQ5k5LJIO3lrf4gRPy nNeWNk+mnbsemCL/aNv1j5YYD0brOeUXL2vTieuSSclmw6TrFypCbaAt+eJ7laisNz0i wYEd2TSqydIGg6yQfFtRV75IT3TAcs9gi19bkGB/5H2AvMPtDjlXcUrP5rkJhOy45IKJ zXOcFdjcV8ZfQulYIqNsYPsiMxQWKWGqW0PBReo7kgH3NzmDhFANsolqtAZoq0XCMmMI RjEEaYynf1dD4d/dJ4MXk0bbT5uQyr1K/Ti/hwLhuN/YhiGfrADGhD4Pf71o+ytVbQ5T ZzJQ== X-Forwarded-Encrypted: i=1; AJvYcCWRy5gIIr7gpPfQtGSTSu9RK7pAEUzlQ3k9CIh79L2AnA3ykcGtpmgmAjcKX9elht/2q9ovwi9HtQ==@kvack.org X-Gm-Message-State: AOJu0YxEGloyPCjbXXywAP2n+AryRg0pU68MoK+2+VC4GmmewZ+FDYn8 p31XIvYoPZWA6DdysICUjP3WaNbzSUYRo+PmajmneLd3xayd5Yq8x5Fv X-Gm-Gg: ASbGncu4NA1xHfd40xAHk5yxq7bX1HvIHLAC17TkUa8cFs6V7S1HcSFCySM3dXr/nr/ GZxW0TTkq3SKV4deMne5//NIg6uP2ZGx94GpxdKIspKPLfQPbBi102+XNmrSVX04NScYBb+hHj4 SUN4XlVXiBdUoSzOoUxnbUbgjCuTe5aVK5cr7Y5dRl6bMcsKeqrj5s5S+TVHLNUaOEVaxKtuNWC qdlu7zQYO1kPXGj4994JzfWg4mutu6s0d12PS7VWG6+3ttgrTFiEfoQ8xonb1izN+BlQVNVxkUN SgBOouRnrtaFbMVYwlrONj3HNBLLX7QBvaM6coDiP9LiCpBH0ioTMHuE4D9JDwOFmSo6x47pvSZ vI6lhkJSqx3YuKaFF0rOngMLcab+1z8C+MZMT1wpNmVUsAWDr/lUdgtY0+Ys/YvJN3i4YhM353Q sAj3TYik4Nwiqg8ZxwWtZGrQ== X-Google-Smtp-Source: AGHT+IHLWcFC7W3aH7MtEyBpRAAfyoGWF1TXnIybIjXPJD9gYvIPg0ozGaDjCXeoqvDbHEVRJoG18g== X-Received: by 2002:a17:902:d481:b0:295:9b73:b15c with SMTP id d9443c01a7336-297e56f9c21mr125602655ad.42.1762792628683; Mon, 10 Nov 2025 08:37:08 -0800 (PST) Received: from localhost ([103.88.46.62]) by smtp.gmail.com with ESMTPSA id d9443c01a7336-29650c5ce87sm150073335ad.29.2025.11.10.08.37.07 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 10 Nov 2025 08:37:08 -0800 (PST) From: Jinchao Wang To: Andrew Morton , "Masami Hiramatsu (Google)" , Peter Zijlstra , Randy Dunlap , Marco Elver , Mike Rapoport , Alexander Potapenko , Adrian Hunter , Alexander Shishkin , Alice Ryhl , Andrey Konovalov , Andrey Ryabinin , Andrii Nakryiko , Ard Biesheuvel , Arnaldo Carvalho de Melo , Ben Segall , Bill Wendling , Borislav Petkov , Catalin Marinas , Dave Hansen , David Hildenbrand , David Kaplan , "David S. Miller" , Dietmar Eggemann , Dmitry Vyukov , "H. Peter Anvin" , Ian Rogers , Ingo Molnar , James Clark , Jinchao Wang , Jinjie Ruan , Jiri Olsa , Jonathan Corbet , Juri Lelli , Justin Stitt , kasan-dev@googlegroups.com, Kees Cook , "Liam R. Howlett" , "Liang Kan" , Linus Walleij , linux-arm-kernel@lists.infradead.org, linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, linux-perf-users@vger.kernel.org, linux-trace-kernel@vger.kernel.org, llvm@lists.linux.dev, Lorenzo Stoakes , Mark Rutland , Masahiro Yamada , Mathieu Desnoyers , Mel Gorman , Michal Hocko , Miguel Ojeda , Nam Cao , Namhyung Kim , Nathan Chancellor , Naveen N Rao , Nick Desaulniers , Rong Xu , Sami Tolvanen , Steven Rostedt , Suren Baghdasaryan , Thomas Gleixner , =?UTF-8?q?Thomas=20Wei=C3=9Fschuh?= , Valentin Schneider , Vincent Guittot , Vincenzo Frascino , Vlastimil Babka , Will Deacon , workflows@vger.kernel.org, x86@kernel.org Subject: [PATCH v8 06/27] mm/ksw: add singleton debugfs interface Date: Tue, 11 Nov 2025 00:36:01 +0800 Message-ID: <20251110163634.3686676-7-wangjinchao600@gmail.com> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20251110163634.3686676-1-wangjinchao600@gmail.com> References: <20251110163634.3686676-1-wangjinchao600@gmail.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Stat-Signature: uwmoxgti9ckfoa5fe7d969fb8qm4omwx X-Rspam-User: X-Rspamd-Queue-Id: CF11B10000F X-Rspamd-Server: rspam10 X-HE-Tag: 1762792629-237500 X-HE-Meta: U2FsdGVkX18y5uTAbVSStjSalAqugiWN4XcMjVTzkcBycijcZY5Jr/kfmO5z1Tx7xzC6UZfNdoOKAN8zsetv3OHIsmO4dDRS7blTztcm99EM2SoXe5liPed1ssdj4hqZ5tkQof/xQnTSBlcyNYsW5l8ARc+FyVdoftneg5qLKErTVvQI2FwCTCa4NXUWAwjHiM4iNE9qxKtQIoMnH+wbvH3OhXF9WrIU8jMdcAQuVmT+44mlfFAecCAAxvOdjLIGYtuYYPxmUg7J0Ai/8UUWsEOXGggoJ2nRc4k86GS84c3qjAur7KhZ1aDWmg2+VEcWLRps1P8slEt8347wyGXnMNWhaVUrtxKMXEk3n5Qf+O6n6LunLUKhV4/B5QQYwxFpKYBF7nPNoxC4R47Jx3JQE8o2d0wbWEcBg4zNc1jszLmwhjb3yyrV8XM3tGDq2zIC86imwQX9i3OCQpcCM56irxbmS9aCHvb/2OahkFUIfwoeJCD6dC5UVxBZS+l6gDUjrfuWCBszyQk2ri2wTctzOY7vn6s/mfw8cw3YjtAgERhOOZ09IuWXpSGMv5lQapYCf47xlk8A60xN6bEV+Pz2zZVx6LLaWoC2KLyRrRlBsCfGUTnf9+X+2U8/uZSnLNSjtkWp6UGII6XkbFlGpiyPf2jnbH6p/k6FQ24f94kngisASnj6FW1S9Vwo63C9aNdIdbZZbBncN7A1t0G2bi4aStvcJtUODzQ7PmdlVTOSn3rhGjpL8y6PUILBzlVtZWCswzgxfUx4ltinEMwjA7LPOcmrqVtuESxvKAtWlCEzzEJVZWic0mRHfCuCBnvvkBxIc1BxKDJ4k7sUlnuHN3Zeb0XiSUKkNYtBbxcf6R3WZio+dxio0y9P8kCt9mvDv6X65bu+BVkAO/kY3V3XPqVMCddnzm6UjTznNtyk8VEqL3ZbswJB7es1XFhFu/Ep1cxHah4GtBEcp+/OdzhaBJM 8rFF6PdV 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 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: List-Subscribe: List-Unsubscribe: Provide the debugfs config file to read or update the configuration. Only a single process can open this file at a time, enforced using atomic config_file_busy, to prevent concurrent access. ksw_get_config() exposes the configuration pointer as const. Signed-off-by: Jinchao Wang --- include/linux/kstackwatch.h | 3 ++ mm/kstackwatch/kernel.c | 103 ++++++++++++++++++++++++++++++++++-- 2 files changed, 103 insertions(+), 3 deletions(-) diff --git a/include/linux/kstackwatch.h b/include/linux/kstackwatch.h index dd00c4c8922e..ada5ac64190c 100644 --- a/include/linux/kstackwatch.h +++ b/include/linux/kstackwatch.h @@ -35,4 +35,7 @@ struct ksw_config { char *user_input; }; +// singleton, only modified in kernel.c +const struct ksw_config *ksw_get_config(void); + #endif /* _KSTACKWATCH_H */ diff --git a/mm/kstackwatch/kernel.c b/mm/kstackwatch/kernel.c index 50104e78cf3d..87fef139f494 100644 --- a/mm/kstackwatch/kernel.c +++ b/mm/kstackwatch/kernel.c @@ -1,13 +1,18 @@ // SPDX-License-Identifier: GPL-2.0 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt +#include #include #include #include #include #include +#include +static atomic_t dbgfs_config_busy = ATOMIC_INIT(0); static struct ksw_config *ksw_config; +static struct dentry *dbgfs_config; +static struct dentry *dbgfs_dir; struct param_map { const char *name; /* long name */ @@ -76,7 +81,7 @@ static int ksw_parse_param(struct ksw_config *config, const char *key, * - sp_offset |so (u16) : offset from stack pointer at func_offset * - watch_len |wl (u16) : watch length (1,2,4,8) */ -static int __maybe_unused ksw_parse_config(char *buf, struct ksw_config *config) +static int ksw_parse_config(char *buf, struct ksw_config *config) { char *part, *key, *val; int ret; @@ -111,18 +116,110 @@ static int __maybe_unused ksw_parse_config(char *buf, struct ksw_config *config) return 0; } +static ssize_t ksw_dbgfs_read(struct file *file, char __user *buf, size_t count, + loff_t *ppos) +{ + return simple_read_from_buffer(buf, count, ppos, ksw_config->user_input, + ksw_config->user_input ? strlen(ksw_config->user_input) : 0); +} + +static ssize_t ksw_dbgfs_write(struct file *file, const char __user *buffer, + size_t count, loff_t *ppos) +{ + char input[MAX_CONFIG_STR_LEN]; + int ret; + + if (count == 0 || count >= sizeof(input)) + return -EINVAL; + + if (copy_from_user(input, buffer, count)) + return -EFAULT; + + input[count] = '\0'; + strim(input); + + if (!strlen(input)) { + pr_info("config cleared\n"); + return count; + } + + ret = ksw_parse_config(input, ksw_config); + if (ret) { + pr_err("Failed to parse config %d\n", ret); + return ret; + } + + return count; +} + +static int ksw_dbgfs_open(struct inode *inode, struct file *file) +{ + if (atomic_cmpxchg(&dbgfs_config_busy, 0, 1)) + return -EBUSY; + return 0; +} + +static int ksw_dbgfs_release(struct inode *inode, struct file *file) +{ + atomic_set(&dbgfs_config_busy, 0); + return 0; +} + +static const struct file_operations kstackwatch_fops = { + .owner = THIS_MODULE, + .open = ksw_dbgfs_open, + .read = ksw_dbgfs_read, + .write = ksw_dbgfs_write, + .release = ksw_dbgfs_release, + .llseek = default_llseek, +}; + +const struct ksw_config *ksw_get_config(void) +{ + return ksw_config; +} + static int __init kstackwatch_init(void) { + int ret = 0; + ksw_config = kzalloc(sizeof(*ksw_config), GFP_KERNEL); - if (!ksw_config) - return -ENOMEM; + if (!ksw_config) { + ret = -ENOMEM; + goto err_alloc; + } + + dbgfs_dir = debugfs_create_dir("kstackwatch", NULL); + if (!dbgfs_dir) { + ret = -ENOMEM; + goto err_dir; + } + + dbgfs_config = debugfs_create_file("config", 0600, dbgfs_dir, NULL, + &kstackwatch_fops); + if (!dbgfs_config) { + ret = -ENOMEM; + goto err_file; + } pr_info("module loaded\n"); return 0; + +err_file: + debugfs_remove_recursive(dbgfs_dir); + dbgfs_dir = NULL; +err_dir: + kfree(ksw_config); + ksw_config = NULL; +err_alloc: + return ret; } static void __exit kstackwatch_exit(void) { + debugfs_remove_recursive(dbgfs_dir); + kfree(ksw_config->func_name); + kfree(ksw_config->user_input); kfree(ksw_config); pr_info("module unloaded\n"); -- 2.43.0