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 144E5CAC5A5 for ; Thu, 25 Sep 2025 02:07:34 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 5ECF38E0010; Wed, 24 Sep 2025 22:07:33 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 5C4218E0001; Wed, 24 Sep 2025 22:07:33 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 4B36C8E0010; Wed, 24 Sep 2025 22:07:33 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0017.hostedemail.com [216.40.44.17]) by kanga.kvack.org (Postfix) with ESMTP id 3809C8E0001 for ; Wed, 24 Sep 2025 22:07:33 -0400 (EDT) Received: from smtpin25.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay04.hostedemail.com (Postfix) with ESMTP id DBC0D1A0208 for ; Thu, 25 Sep 2025 02:07:32 +0000 (UTC) X-FDA: 83926135944.25.680FC34 Received: from mail-pg1-f176.google.com (mail-pg1-f176.google.com [209.85.215.176]) by imf21.hostedemail.com (Postfix) with ESMTP id 0B8391C000C for ; Thu, 25 Sep 2025 02:07:30 +0000 (UTC) Authentication-Results: imf21.hostedemail.com; dkim=pass header.d=gmail.com header.s=20230601 header.b=Q7HDxj8D; spf=pass (imf21.hostedemail.com: domain of wangjinchao600@gmail.com designates 209.85.215.176 as permitted sender) smtp.mailfrom=wangjinchao600@gmail.com; dmarc=pass (policy=none) header.from=gmail.com ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1758766051; 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-type:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=z3v0KAw/a5VLZK8q/426U2Svx1Ly/zqTFJD1qMEvdMs=; b=vHQzJ3EF4nGfqMhb2VF3aa0av40dAf8fPpFGnl3kFkyt4qRtYUdP+m6XlBTVhtAVr8/miw n2lDS7eCwDnPJ7dzLka9WFzuspVExzwBf6ZyBlOrebPmeVoHq4SPfXf2xhcZF7fgzRH9KF ek9V7FNVZtCXYUyDRID2obeGNlIDeyA= ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1758766051; a=rsa-sha256; cv=none; b=SnJj6TWZy2eEI0yQdi723WnhXlu751woRf9slX+uWSQORX7LwQa7UgmNC6h0QRQUA4B5Yr VR4TuNyrPbU8oo0csIHTq20Nc58jRtSuLAUjYXluK2cIBEvJBEZ5EcAr+bC+xbm10dgEeW UXX4eL30is8SlMr8CJJCtkekn+9yB6U= ARC-Authentication-Results: i=1; imf21.hostedemail.com; dkim=pass header.d=gmail.com header.s=20230601 header.b=Q7HDxj8D; spf=pass (imf21.hostedemail.com: domain of wangjinchao600@gmail.com designates 209.85.215.176 as permitted sender) smtp.mailfrom=wangjinchao600@gmail.com; dmarc=pass (policy=none) header.from=gmail.com Received: by mail-pg1-f176.google.com with SMTP id 41be03b00d2f7-b5526b7c54eso291343a12.0 for ; Wed, 24 Sep 2025 19:07:30 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20230601; t=1758766050; x=1759370850; darn=kvack.org; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:from:to:cc:subject:date:message-id:reply-to; bh=z3v0KAw/a5VLZK8q/426U2Svx1Ly/zqTFJD1qMEvdMs=; b=Q7HDxj8DivVYVnc+Yh70MgHaEcBUfdOehptVXeuGlzkTUB5xEyJDgktKHQLRgtX4I+ xjcR9tJLe2fsd81wqxK+aC7Uxidb4Nxe7ox+992MSrnlflEWT6dor/wHgZ41cciWifnO A+yDTA+loJHl7GJW2HBXFIhGP8hQ+AqENvBlkGuFtJi+VN2rfrZdTz5eejMDZHDqkBNB ZH0OgCcNtfE72dNGXLfCYB6aw9P42Acb5fgmvfxbXhEoAnfZMXxVVZyhzkdb6M7jLdlm tJjuNpDyUtsr4v8DQwBrAWT8/gb7NiDXAjqYXosUwKNG9KyvocwTZH0GXVtmJKRwJK+1 Vh+w== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1758766050; x=1759370850; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:x-gm-message-state:from:to:cc:subject:date :message-id:reply-to; bh=z3v0KAw/a5VLZK8q/426U2Svx1Ly/zqTFJD1qMEvdMs=; b=UZZpx2YXTGx5BXkw8JfKZDZ0IlYR+uws7SnVg1ReVGXLAUGqbW5cta/MT3L52wleR5 ehyaGY8Sxc3kJz5YGsVV5PF1q/KgnNfs4U4Eo7ofbDbGC2RVhzQW0NPF8/PJdiXp07du 3wUIRbfukVjpf/fYhc0+Ocx1j8v9/xk+gRmgGFGlPhgsFqCi67BEwlUu/CdQRtc1Ms1+ aAsAuYHCDUEuRmtwD4uvaVEPS/BP/9rKmFfw3FL1zqNScpaz3i9egAS0mDWy3B2Kq53v UBwKp6FrJdj/SnQyTfkjmPeadLxWdWuSSWDuLOw1AMSMGT0XHk2mFw553V2WEDouV0M+ 6MdQ== X-Forwarded-Encrypted: i=1; AJvYcCWzm8JhW8ldSxu1IgPa+OZAvXlmlxiRteh0llh7rquEvHV5scZ91jai+3tajU367Mmg8VHx12xDcg==@kvack.org X-Gm-Message-State: AOJu0Yz8LEEqTOQyOfEyMsCaj5o/aRhEMvUHSNpVLehOzWPjdR2K/ho5 KuOsM9cxHqJZcwjy6ePK1XAyyXp+wR6LaJG5WLjFRE9aqqdJrsip2qUU X-Gm-Gg: ASbGncsW+VwEdKEIsXADwRUTc1gPo3DjRu2mNiRtNks9M+LxIj7EU+thSXwzeqP34bF aicgwEBBuhtjYVwgNIb+BNYRqr/uJ2XptPE8KrKoWg88JZX2u83Jc/oBdILPgCWSdt32Z5Xwhd1 fy5zRk41Mmo7o9UYgLoL/c3BwBYJDsEMieTdi/tlejpEJXuW6IYLnihAkqO621+h0luIyKBGFOq z5mCoF02WeX2vCjxy0pcNkBi4Yzh3ifl3G9X+d5H92GGhi+KkXyfrSG1WbbVLu2yjLvKwJIqv7H 7cuWmsPVduzU7729ryNEN9liVW0l9phTQsgxX5BsYzJStqV7QCMzPdVAirII4XZ0Zod12qb8d7d 8FkP0CJveqFrAAOBobFSSiWffiRKVDcIP4A== X-Google-Smtp-Source: AGHT+IHZwY+E9Zl/mOnS/wW2XcXo5Et3bKXZYRlw/VXukF+oo1CmX+XrzU+9/LJydGwruFBdmu625g== X-Received: by 2002:a17:902:fccf:b0:273:31fb:a872 with SMTP id d9443c01a7336-27ed4a06cefmr13125795ad.6.1758766049602; Wed, 24 Sep 2025 19:07:29 -0700 (PDT) Received: from localhost ([103.88.46.62]) by smtp.gmail.com with ESMTPSA id d9443c01a7336-27ed6abff9fsm6469775ad.133.2025.09.24.19.07.28 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 24 Sep 2025 19:07:28 -0700 (PDT) Date: Thu, 25 Sep 2025 10:07:26 +0800 From: Jinchao Wang To: Marco Elver Cc: Andrew Morton , Masami Hiramatsu , Peter Zijlstra , Mike Rapoport , Alexander Potapenko , Randy Dunlap , Jonathan Corbet , Thomas Gleixner , Ingo Molnar , Borislav Petkov , Dave Hansen , x86@kernel.org, "H. Peter Anvin" , Juri Lelli , Vincent Guittot , Dietmar Eggemann , Steven Rostedt , Ben Segall , Mel Gorman , Valentin Schneider , Arnaldo Carvalho de Melo , Namhyung Kim , Mark Rutland , Alexander Shishkin , Jiri Olsa , Ian Rogers , Adrian Hunter , "Liang, Kan" , David Hildenbrand , Lorenzo Stoakes , "Liam R. Howlett" , Vlastimil Babka , Suren Baghdasaryan , Michal Hocko , Nathan Chancellor , Nick Desaulniers , Bill Wendling , Justin Stitt , Kees Cook , Alice Ryhl , Sami Tolvanen , Miguel Ojeda , Masahiro Yamada , Rong Xu , Naveen N Rao , David Kaplan , Andrii Nakryiko , Jinjie Ruan , Nam Cao , workflows@vger.kernel.org, linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, linux-perf-users@vger.kernel.org, linux-mm@kvack.org, llvm@lists.linux.dev, Andrey Ryabinin , Andrey Konovalov , Dmitry Vyukov , Vincenzo Frascino , kasan-dev@googlegroups.com, "David S. Miller" , Mathieu Desnoyers , linux-trace-kernel@vger.kernel.org Subject: Re: [PATCH v5 06/23] mm/ksw: add singleton /proc/kstackwatch interface Message-ID: References: <20250924115124.194940-1-wangjinchao600@gmail.com> <20250924115124.194940-7-wangjinchao600@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: X-Rspamd-Queue-Id: 0B8391C000C X-Stat-Signature: kpddqkhs4m753a1ffhbb7cgbcbgsduow X-Rspam-User: X-Rspamd-Server: rspam09 X-HE-Tag: 1758766050-525322 X-HE-Meta: U2FsdGVkX19SMtypsVHLFK7Oh5J2nebzf0JcMIl3JOHu8NcQA4Gss3XCVLxUEtEn+H0yMpYF3pOWjXPLonRK+jEKQS7WE/Aln8sxvTdUNj7Shg9g3sXCRz2vsmx17kBImN7/+NG78eV3IKwPwciY/ZuOG78s08LLkI1YnelOXTo7zjwDAdLUBr5zVu/DKnPj3138yZylpZFG9EJcHir87w7GSM/ZGfWmjOCqvdJcn08gI1Cq3e7Hcc7L/x880g+F6soz26EdHRaI8UYYzlWGINQnHCM2edK0OlLz13hRnfkmv9yxWuE2K9TBUy1ES5iYOnJ7ZPP5HgKukqqJfHptKl2zr5+JSGtIfp985KAfNvZVJ5e7d0I97o8Rja3YQzXzrNu3C82H4u0906XmMd61Xw78kVacaWA7HQubCq/lvLX+Nq9lWozpQbXYHN7tYPQXaY2/z7AHv7OTPfE6Asq99z6eCR+T9iT0n0fhYlJ17ZiQMPO1H+KSNOEC0JaOl6qCo1jOi5mahcobo57uP9JZIQXm2qVmMsQtziutP/mexzsIXbuKGtiaRlG1XQwjp53Wk3GSmTY6wMkFKHiHF/aB3mNVag9JQ2xzOlIlHkwLAPzNZNILVE/YH/c3SlHJUH/4K4F7grVmOvBYZg2nN3uHrOclY0J9BKrd1DWjQRNARTiT6xGdINkUsGTAxTmU0go2D4OTStj5+7H9pp43vJ1lEP2EYQpiPVTt7rjqBCaLXvfDHCi+Y1OACLJ6oEFd8m8KBA2PwrV/V/c1hjolJmMICx9oR+85GPPWo3GEJoGROIHV1uhRhHDkO/yg39d5sHRZns83BAMQBLwMFAmgw0nulQoVTgz3x8YnvajOUoZRcQvzuHUUoyik6N9bAzldMduWgoTTC5N59PkQz6euOw0lTRz+scn5jnzkuLuIJqSZdW503IdHz8ZrY7q79398gewmhLoIBDJYxxBA6nTAUUC 4AO6U12o 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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: On Wed, Sep 24, 2025 at 10:49:35PM +0200, Marco Elver wrote: > On Wed, 24 Sept 2025 at 13:51, Jinchao Wang wrote: > > > > Provide the /proc/kstackwatch 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. > > Why is this in /proc and not debugfs? Thanks, will fix in next version. > > > ksw_get_config() exposes the configuration pointer as const. > > > > Signed-off-by: Jinchao Wang > > --- > > mm/kstackwatch/kernel.c | 77 +++++++++++++++++++++++++++++++++++- > > mm/kstackwatch/kstackwatch.h | 3 ++ > > 2 files changed, 79 insertions(+), 1 deletion(-) > > > > diff --git a/mm/kstackwatch/kernel.c b/mm/kstackwatch/kernel.c > > index 3b7009033dd4..4a06ddadd9c7 100644 > > --- a/mm/kstackwatch/kernel.c > > +++ b/mm/kstackwatch/kernel.c > > @@ -3,11 +3,15 @@ > > > > #include > > #include > > +#include > > +#include > > #include > > +#include > > > > #include "kstackwatch.h" > > > > static struct ksw_config *ksw_config; > > +static atomic_t config_file_busy = ATOMIC_INIT(0); > > > > struct param_map { > > const char *name; /* long name */ > > @@ -74,7 +78,7 @@ 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; > > @@ -109,18 +113,89 @@ static int __maybe_unused ksw_parse_config(char *buf, struct ksw_config *config) > > return 0; > > } > > > > +static ssize_t kstackwatch_proc_write(struct file *file, > > + const char __user *buffer, size_t count, > > + loff_t *pos) > > +{ > > + 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 kstackwatch_proc_show(struct seq_file *m, void *v) > > +{ > > + seq_printf(m, "%s\n", ksw_config->user_input); > > + return 0; > > +} > > + > > +static int kstackwatch_proc_open(struct inode *inode, struct file *file) > > +{ > > + if (atomic_cmpxchg(&config_file_busy, 0, 1)) > > + return -EBUSY; > > + > > + return single_open(file, kstackwatch_proc_show, NULL); > > +} > > + > > +static int kstackwatch_proc_release(struct inode *inode, struct file *file) > > +{ > > + atomic_set(&config_file_busy, 0); > > + return single_release(inode, file); > > +} > > + > > +static const struct proc_ops kstackwatch_proc_ops = { > > + .proc_open = kstackwatch_proc_open, > > + .proc_read = seq_read, > > + .proc_write = kstackwatch_proc_write, > > + .proc_lseek = seq_lseek, > > + .proc_release = kstackwatch_proc_release, > > +}; > > + > > +const struct ksw_config *ksw_get_config(void) > > +{ > > + return ksw_config; > > +} > > static int __init kstackwatch_init(void) > > { > > ksw_config = kzalloc(sizeof(*ksw_config), GFP_KERNEL); > > if (!ksw_config) > > return -ENOMEM; > > > > + if (!proc_create("kstackwatch", 0600, NULL, &kstackwatch_proc_ops)) { > > + pr_err("create proc kstackwatch fail"); > > + kfree(ksw_config); > > + return -ENOMEM; > > + } > > + > > pr_info("module loaded\n"); > > return 0; > > } > > > > static void __exit kstackwatch_exit(void) > > { > > + remove_proc_entry("kstackwatch", NULL); > > + kfree(ksw_config->func_name); > > + kfree(ksw_config->user_input); > > kfree(ksw_config); > > > > pr_info("module unloaded\n"); > > diff --git a/mm/kstackwatch/kstackwatch.h b/mm/kstackwatch/kstackwatch.h > > index a7bad207f863..983125d5cf18 100644 > > --- a/mm/kstackwatch/kstackwatch.h > > +++ b/mm/kstackwatch/kstackwatch.h > > @@ -29,4 +29,7 @@ struct ksw_config { > > char *user_input; > > }; > > > > +// singleton, only modified in kernel.c > > +const struct ksw_config *ksw_get_config(void); > > + > > #endif /* _KSTACKWATCH_H */ > > -- > > 2.43.0 > > > > -- > > You received this message because you are subscribed to the Google Groups "kasan-dev" group. > > To unsubscribe from this group and stop receiving emails from it, send an email to kasan-dev+unsubscribe@googlegroups.com. > > To view this discussion visit https://groups.google.com/d/msgid/kasan-dev/20250924115124.194940-7-wangjinchao600%40gmail.com. -- Jinchao