From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-pl1-f175.google.com (mail-pl1-f175.google.com [209.85.214.175]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id DB27723FC66 for ; Tue, 30 Sep 2025 02:45:45 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.214.175 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1759200348; cv=none; b=oMJYLfVKz7WrOI0+XjXaEE1mkQDiDpwqxRxEF5tZefLesRvkYlKD4KaOhH90U1uUFtp9wP3/lJST4JBgNcv7gYJfnfmEukhAKltyfve5aKoXzCC9xXaVliMczgUaatQWGFvHTwpmg3BRIJKAHdA6ADme+F23Qbup5h+Ch/MoUAY= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1759200348; c=relaxed/simple; bh=fq2Ne6eA5Hj+u/oZogdwy0lpJa+hkt/8IQwPQXp6BxM=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=RqXXE9rGSoNAWit7jHFOvYNVP5M0WAMXQkWWQhJ+5L4ZbWlWNX03rhUd1t2L7mStj7PjMRtP5+dIzuBKd5zpCjqHHY040JCb6/KYZU18KpJ151a9PvH799IkAkQNLr5BxkBn/xF0+FrbZ2dgbVISURSb8AsSbDRGNKLJHKugWcY= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com; spf=pass smtp.mailfrom=gmail.com; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b=S3OCE1Qn; arc=none smtp.client-ip=209.85.214.175 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=gmail.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="S3OCE1Qn" Received: by mail-pl1-f175.google.com with SMTP id d9443c01a7336-27eed7bdfeeso51704325ad.0 for ; Mon, 29 Sep 2025 19:45:45 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20230601; t=1759200345; x=1759805145; darn=vger.kernel.org; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to; bh=3Zjn9o91E8eMF6fANpWy8yJadTo2vfyIghwnTsVomDQ=; b=S3OCE1Qn3i6Mw2qE81obgRu0NwIi61Lr4Efgpvr+CcWW8G/74bp7n2rpGMKDOG22uc IHOuyNH5sQfPL/EsVktHvPR1H0i11elFSNrxxkgIgElq6QJZIQKV/WMsTB8JvPuVvYsQ MPEKEOjSAcV0/JJEnfUhD/L0tr2OsW4CeIZdC4mRxG3DF8zrIsWy0BzTYh3YzmmKjnEW HPuQQKoQyRrkJhoS0SnqKwF5oP6ZcXPNeiwoWXePWQMOCbKPBOECu4mAQLDpwnfPYgtZ t1/Q7vNOikuiFZWWsGTPcJAJ5RyERubmoC5IqoQTedFRQlOZw9+1MyiBPLKD3czytFno B8rw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1759200345; x=1759805145; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=3Zjn9o91E8eMF6fANpWy8yJadTo2vfyIghwnTsVomDQ=; b=JaNLsZdfkNp1LZ6whMAYhYKI+eb5ziOnBJMn2NwU4o9uYvZEoFg4729m3/phyzNRJR GbwChe43CCPDeE+tmypYLcU4xx4EoSVuN7E49tXhxiQe5c33yOeaWcfijCtvnpASdTCF W3wC4jn1gKYMzvwAv+gXT/3wLRd3aAxj119x2fY6QnN8UCpGA1VgPafaoTggAobSuja+ Fk09PEOeRUbb/sYKbc3EWo8q4g6ebm+LR/WGgxgdYS/RJ11ueYT+nKhRApX1Lb9wSZ07 qUMfFBDchYQpmuAWo5R8P1V/XPo9X5Wfv0UHy5u7VDCNqUPAnFbcJN6AE8cOiaTDAxm6 6nDw== X-Forwarded-Encrypted: i=1; AJvYcCWjmbMwCXg9lj9KUmx6f1t36RlqnBHAquz//ZJdzGY8ePLG7hnTxyddpFltTxX/oEggjXkPR9WC8yw=@vger.kernel.org X-Gm-Message-State: AOJu0YzGadyLxHYpX2WIPC/SdloW3vFNNESvYI+SKXuMLh6Wy5+WUF/y oJpXzvwXmbGWMHQXoAMUf3PFcEppTDcaQDSGR7Ych9RwgjgMWfLVsE4+ X-Gm-Gg: ASbGncvn5/a6SQPwvuRW99G1qNynE5EmuK3JXU8hQVxkMfrwkW3iTS4hEsJe7boIrLq PQmx15eQoSSIUC82cqbxeYhwaCnHwjRO11ItI7N4Kx2Z4m7qmAehlEC9LwRC6NbG9cE9z0xkaAs TnRsipfxwThZ5M4yLObm69DjCTLOQCi99d+5HyIqNlIggSbvuFbic3O8H+MbrBdGJ6RFcjOhCCt Q2wtdXoCt2NGZndQPpLOT9zC1w63R/ty++xWcouS6K7VBPO3wB3jbgt5fKNSev6qB5YYJ0XY+ct QKlYxXkbIx6VDvocLME9WPMinoMUvswynp/M77FAXzNRuRBYVIpW04zIRCos/xLlS2la+FSNquz wIBrdlUfKVhq8FbSNbezUD8RQtkPxayyqlpztmxsmcIcbqK/0H7/QfG9hKpeDeGJ/UiyyEWxVsH Ku X-Google-Smtp-Source: AGHT+IG/V+l4d2YJ6ds5JXx6iWxJNgpfbKQaTWJecBpgg+jS+5oh1BhPKfXY/R3RErss9TGYBDL6Iw== X-Received: by 2002:a17:903:2f4e:b0:25d:510:622c with SMTP id d9443c01a7336-28d1718d306mr31185225ad.28.1759200345170; Mon, 29 Sep 2025 19:45:45 -0700 (PDT) Received: from localhost ([45.142.167.196]) by smtp.gmail.com with ESMTPSA id d9443c01a7336-27eea801b49sm118165465ad.23.2025.09.29.19.45.44 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 29 Sep 2025 19:45:44 -0700 (PDT) From: Jinchao Wang To: Andrew Morton , Masami Hiramatsu , Peter Zijlstra , Mike Rapoport , Alexander Potapenko , Randy Dunlap , Marco Elver , 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 Cc: Jinchao Wang Subject: [PATCH v6 17/23] mm/ksw: add test module Date: Tue, 30 Sep 2025 10:43:38 +0800 Message-ID: <20250930024402.1043776-18-wangjinchao600@gmail.com> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20250930024402.1043776-1-wangjinchao600@gmail.com> References: <20250930024402.1043776-1-wangjinchao600@gmail.com> Precedence: bulk X-Mailing-List: workflows@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Add a standalone test module for KStackWatch to validate functionality in controlled scenarios. The module exposes a simple interface via debugfs (/sys/kernel/debug/kstackwatch/test), allowing specific test cases to be triggered with commands such as: echo test0 > /sys/kernel/debug/kstackwatch/test To ensure predictable behavior during testing, the module is built with optimizations disabled. Signed-off-by: Jinchao Wang --- mm/Kconfig.debug | 10 +++ mm/kstackwatch/Makefile | 6 ++ mm/kstackwatch/kernel.c | 5 ++ mm/kstackwatch/kstackwatch.h | 2 + mm/kstackwatch/test.c | 121 +++++++++++++++++++++++++++++++++++ 5 files changed, 144 insertions(+) create mode 100644 mm/kstackwatch/test.c diff --git a/mm/Kconfig.debug b/mm/Kconfig.debug index 24f4c4254f01..224bd561dcbb 100644 --- a/mm/Kconfig.debug +++ b/mm/Kconfig.debug @@ -317,3 +317,13 @@ config KSTACK_WATCH A lightweight real-time debugging tool to detect stack corruption. If unsure, say N. + +config KSTACK_WATCH_TEST + tristate "KStackWatch Test Module" + depends on KSTACK_WATCH + help + This module provides controlled stack corruption scenarios to verify + the functionality of KStackWatch. It is useful for development and + validation of KStackWatch mechanism. + + If unsure, say N. diff --git a/mm/kstackwatch/Makefile b/mm/kstackwatch/Makefile index 84a46cb9a766..d007b8dcd1c6 100644 --- a/mm/kstackwatch/Makefile +++ b/mm/kstackwatch/Makefile @@ -1,2 +1,8 @@ obj-$(CONFIG_KSTACK_WATCH) += kstackwatch.o kstackwatch-y := kernel.o stack.o watch.o + +obj-$(CONFIG_KSTACK_WATCH_TEST) += kstackwatch_test.o +kstackwatch_test-y := test.o +CFLAGS_test.o := -fno-inline \ + -fno-optimize-sibling-calls \ + -fno-pic -fno-pie -O0 -Og diff --git a/mm/kstackwatch/kernel.c b/mm/kstackwatch/kernel.c index 57628bace365..12b2f5ceb5d4 100644 --- a/mm/kstackwatch/kernel.c +++ b/mm/kstackwatch/kernel.c @@ -233,6 +233,11 @@ const struct ksw_config *ksw_get_config(void) return ksw_config; } +struct dentry *ksw_get_dbgdir(void) +{ + return dbgfs_dir; +} + static int __init kstackwatch_init(void) { int ret = 0; diff --git a/mm/kstackwatch/kstackwatch.h b/mm/kstackwatch/kstackwatch.h index 528001534047..b7361d5d071d 100644 --- a/mm/kstackwatch/kstackwatch.h +++ b/mm/kstackwatch/kstackwatch.h @@ -34,6 +34,8 @@ struct ksw_config { // singleton, only modified in kernel.c const struct ksw_config *ksw_get_config(void); +struct dentry *ksw_get_dbgdir(void); + /* stack management */ int ksw_stack_init(void); diff --git a/mm/kstackwatch/test.c b/mm/kstackwatch/test.c new file mode 100644 index 000000000000..80fec9cf3243 --- /dev/null +++ b/mm/kstackwatch/test.c @@ -0,0 +1,121 @@ +// SPDX-License-Identifier: GPL-2.0 +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#include "kstackwatch.h" + +static struct dentry *test_file; + +#define BUFFER_SIZE 32 + +static void test_watch_fire(void) +{ + u64 buffer[BUFFER_SIZE] = { 0 }; + + pr_info("entry of %s\n", __func__); + ksw_watch_show(); + ksw_watch_fire(); + pr_info("buf[0]:%lld\n", buffer[0]); + + barrier_data(buffer); + pr_info("exit of %s\n", __func__); +} + +static ssize_t test_dbgfs_write(struct file *file, const char __user *buffer, + size_t count, loff_t *pos) +{ + char cmd[256]; + int test_num; + + if (count >= sizeof(cmd)) + return -EINVAL; + + if (copy_from_user(cmd, buffer, count)) + return -EFAULT; + + cmd[count] = '\0'; + strim(cmd); + + pr_info("received command: %s\n", cmd); + + if (sscanf(cmd, "test%d", &test_num) == 1) { + switch (test_num) { + case 0: + test_watch_fire(); + break; + default: + pr_err("Unknown test number %d\n", test_num); + return -EINVAL; + } + } else { + pr_err("invalid command format. Use 'testN'.\n"); + return -EINVAL; + } + + return count; +} + +static ssize_t test_dbgfs_read(struct file *file, char __user *buffer, + size_t count, loff_t *ppos) +{ + static const char usage[] = + "KStackWatch Simplified Test Module\n" + "============ usage ===============\n" + "Usage:\n" + "echo test{i} > /sys/kernel/debug/kstackwatch/test\n" + " test0 - test watch fire\n"; + + return simple_read_from_buffer(buffer, count, ppos, usage, + strlen(usage)); +} + +static const struct file_operations test_dbgfs_fops = { + .owner = THIS_MODULE, + .read = test_dbgfs_read, + .write = test_dbgfs_write, + .llseek = noop_llseek, +}; + +static int __init kstackwatch_test_init(void) +{ + struct dentry *ksw_dir = ksw_get_dbgdir(); + + if (!ksw_dir) { + pr_err("kstackwatch must be loaded first\n"); + return -ENODEV; + } + + test_file = debugfs_create_file("test", 0600, ksw_dir, NULL, + &test_dbgfs_fops); + if (!test_file) { + pr_err("Failed to create debugfs test file\n"); + return -ENOMEM; + } + + pr_info("module loaded\n"); + return 0; +} + +static void __exit kstackwatch_test_exit(void) +{ + debugfs_remove(test_file); + pr_info("module unloaded\n"); +} + +module_init(kstackwatch_test_init); +module_exit(kstackwatch_test_exit); + +MODULE_AUTHOR("Jinchao Wang"); +MODULE_DESCRIPTION("KStackWatch Test Module"); +MODULE_LICENSE("GPL"); -- 2.43.0