From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-pj1-f51.google.com (mail-pj1-f51.google.com [209.85.216.51]) (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 E80B82E62C5 for ; Thu, 9 Oct 2025 10:57:35 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.216.51 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1760007458; cv=none; b=aku1aTerRZkO7v6pFQ5CVW1cgd+cHFBU9gvWzrgnA36fsdmtn+XjQMnj/5BTV8MX1ngI+F4gnWoUhBn6lFn6xXGYYYS9A8g8DcO6vUgoxAGp6ircYaTP2/KhN6kylU+/9QLvSOvKFeX+83lXqoMmh3koYvcm4C5whIWYF75+pAs= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1760007458; c=relaxed/simple; bh=nvDFxA5+kzzGy254IQd/07joD3bGnycuza2xxZ+JqIE=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=oK5eKoQ/JpARq9oD/n//oaeUWeqzBFQY/JCZUwpaJRDANj2B29DWezHNlcANJo7Au+fquVq4FD0/SuXmozu9KRXbfSWIcOusnDN5R5nFCJaLLBOnSHIwTy+ydyy7c6L8oTdH4cnAhjfpA8umEJADdHYa49fHR/FBoOCyImHQFqw= 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=Y9ISfsas; arc=none smtp.client-ip=209.85.216.51 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="Y9ISfsas" Received: by mail-pj1-f51.google.com with SMTP id 98e67ed59e1d1-32ed19ce5a3so837657a91.0 for ; Thu, 09 Oct 2025 03:57:35 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20230601; t=1760007455; x=1760612255; 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=5NW3rnfkFZjd7Zh69vJKiLybxjQ5f/0P49rVAWgM4UU=; b=Y9ISfsasCCtIs06k7SAorawKk7CU6wlYPqtH/S/Nsvt88EBa6xCfDMhUz4EYP8QapA g2/4KwXps2dU+ncJwK80GttoBkJTvB15Yf4d/0jWMxB5nA8Q8Y619UD7m4AK7p8tonnO D9VLgyBa2ChqdkzZ8ijsQii2RWZnZ/icCrfDg5M3KXzZGlu3oRwd+z6mCEBx+rAZwftN GUdknLnGg7Z4utFvSdAn0J6yC401cfSqC4Nb2lKdBJ5keCc6AtU9QbuV/6Fv6ChJij4E 8D1cJ9lc0cs0GUMBE2CXjt3gRBvMk71svaL04UmdccFHa0hh4H9hmGKa7X4DBB80RfUt OoFA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1760007455; x=1760612255; 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=5NW3rnfkFZjd7Zh69vJKiLybxjQ5f/0P49rVAWgM4UU=; b=jWo45+RRl8H6+TBiNq6WXI5FQV971KWJI13zaMwX6aseOsxDfFAZHsRMSGsS0VwcpH nZCOhD7mPI2L9CkplYT2bXzSQjE6hTbUNnHLJIzbXlzTXHzxOoraE4KnUurLdT2mGqVd +JcFscfwTMG/bZbx8i9sZU4898nHdC1z1gk4PT+XC0KvIQ9mRGH7Iqo82ImuYzjCguZL fJE2fF3sHgW9PaeNqHWrJjI9l4CntqPdk/CRqa2FXO02r1dpwYJfeHfhpgaEVajHVmzy Tz/2J5oGUHXbScMYcB9L0VsNdbYqsgqkfG+y+w0EXElKwc0++P6Hje6uCKGEYtKvYZwI /ThQ== X-Forwarded-Encrypted: i=1; AJvYcCWPznc8+zz+dhtsdCxZmraJJEScKmSdFgeV5hgPTJPWg1I2fCow0jL7PQtkpflIJwi86/T2ScTZ3DU=@vger.kernel.org X-Gm-Message-State: AOJu0YzGTKTGq2c3Cs6ngtnSYOHEWyBkQMFbW9UEBD/2VOp33cpc7Qt4 SusoJmpE5CxXGRMxxMJ8nQLKrb40oFgb7sr0fJ2NwdTsdTyXwzXHp6sF X-Gm-Gg: ASbGncvD/5UJSkCNmfvpbyEeBbt4UlqvIONrscx69wWqwOgDYg3x/wx/vehJxY614E5 rkhXH9nwl37biVcVJEiSf6dipYf8UoidoGbGwBvTb4uTfDqKtTN2mRTDG+0VYBFF4ID08ulqi9S 2jSJ2nFctiMhD+bFIZoYgeJte7Q6qLxh4RK2BTwYDcKwAetTLXZiXb3P+w2y/R38NTK8cy/vkD8 AUrTlMFHgyILYBYIpUujSoe8dn5tLe7XTy8GaVCUZ5FHbdMAgjUuHmrVExQUl0hpSWQsSR2P7Ts mKiSiUzaTRVMSPNRA+MpW8wEKXdp4kUPvhO+cdBkEkAKFtFMPqf8TZi60sQ1TijWwQaQtR8TAwA +WYzkphgt0VvHkci00GkbEXP2ljL5kzKOXtka+PLjmznWlhsy8H+h4Na6Gfue X-Google-Smtp-Source: AGHT+IFC13odZspSVqGRoywijSg0VBbkFQPkMFOijqia9KTXZKXwmvUEM0W1W0I7XOEEhq8lnQYbLg== X-Received: by 2002:a17:90b:2249:b0:32b:cafc:e339 with SMTP id 98e67ed59e1d1-33b5139c4f4mr8493028a91.36.1760007455151; Thu, 09 Oct 2025 03:57:35 -0700 (PDT) Received: from localhost ([45.142.165.62]) by smtp.gmail.com with ESMTPSA id 98e67ed59e1d1-33b510fc5e6sm6727834a91.6.2025.10.09.03.57.34 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 09 Oct 2025 03:57:34 -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 v7 07/23] mm/ksw: add HWBP pre-allocation Date: Thu, 9 Oct 2025 18:55:43 +0800 Message-ID: <20251009105650.168917-8-wangjinchao600@gmail.com> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20251009105650.168917-1-wangjinchao600@gmail.com> References: <20251009105650.168917-1-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 Pre-allocate per-CPU hardware breakpoints at init with a place holder address, which will be retargeted dynamically in kprobe handler. This avoids allocation in atomic context. At most max_watch breakpoints are allocated (0 means no limit). Signed-off-by: Jinchao Wang --- mm/kstackwatch/kstackwatch.h | 13 +++++ mm/kstackwatch/watch.c | 97 ++++++++++++++++++++++++++++++++++++ 2 files changed, 110 insertions(+) diff --git a/mm/kstackwatch/kstackwatch.h b/mm/kstackwatch/kstackwatch.h index 983125d5cf18..4eac1be3b325 100644 --- a/mm/kstackwatch/kstackwatch.h +++ b/mm/kstackwatch/kstackwatch.h @@ -2,6 +2,9 @@ #ifndef _KSTACKWATCH_H #define _KSTACKWATCH_H +#include +#include +#include #include #define MAX_CONFIG_STR_LEN 128 @@ -32,4 +35,14 @@ struct ksw_config { // singleton, only modified in kernel.c const struct ksw_config *ksw_get_config(void); +/* watch management */ +struct ksw_watchpoint { + struct perf_event *__percpu *event; + struct perf_event_attr attr; + struct llist_node node; // for atomic watch_on and off + struct list_head list; // for cpu online and offline +}; +int ksw_watch_init(void); +void ksw_watch_exit(void); + #endif /* _KSTACKWATCH_H */ diff --git a/mm/kstackwatch/watch.c b/mm/kstackwatch/watch.c index cec594032515..1d8e24fede54 100644 --- a/mm/kstackwatch/watch.c +++ b/mm/kstackwatch/watch.c @@ -1 +1,98 @@ // SPDX-License-Identifier: GPL-2.0 +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt + +#include +#include +#include +#include +#include + +#include "kstackwatch.h" + +static LLIST_HEAD(free_wp_list); +static LIST_HEAD(all_wp_list); +static DEFINE_MUTEX(all_wp_mutex); + +static ulong holder; +bool panic_on_catch; +module_param(panic_on_catch, bool, 0644); +MODULE_PARM_DESC(panic_on_catch, "panic immediately on corruption catch"); + +static void ksw_watch_handler(struct perf_event *bp, + struct perf_sample_data *data, + struct pt_regs *regs) +{ + pr_err("========== KStackWatch: Caught stack corruption =======\n"); + pr_err("config %s\n", ksw_get_config()->user_input); + dump_stack(); + pr_err("=================== KStackWatch End ===================\n"); + + if (panic_on_catch) + panic("Stack corruption detected"); +} + +static int ksw_watch_alloc(void) +{ + int max_watch = ksw_get_config()->max_watch; + struct ksw_watchpoint *wp; + int success = 0; + int ret; + + init_llist_head(&free_wp_list); + + //max_watch=0 means at most + while (!max_watch || success < max_watch) { + wp = kzalloc(sizeof(*wp), GFP_KERNEL); + if (!wp) + return success > 0 ? success : -EINVAL; + + hw_breakpoint_init(&wp->attr); + wp->attr.bp_addr = (ulong)&holder; + wp->attr.bp_len = sizeof(ulong); + wp->attr.bp_type = HW_BREAKPOINT_W; + wp->event = register_wide_hw_breakpoint(&wp->attr, + ksw_watch_handler, wp); + if (IS_ERR((void *)wp->event)) { + ret = PTR_ERR((void *)wp->event); + kfree(wp); + return success > 0 ? success : ret; + } + llist_add(&wp->node, &free_wp_list); + mutex_lock(&all_wp_mutex); + list_add(&wp->list, &all_wp_list); + mutex_unlock(&all_wp_mutex); + success++; + } + + return success; +} + +static void ksw_watch_free(void) +{ + struct ksw_watchpoint *wp, *tmp; + + mutex_lock(&all_wp_mutex); + list_for_each_entry_safe(wp, tmp, &all_wp_list, list) { + list_del(&wp->list); + unregister_wide_hw_breakpoint(wp->event); + kfree(wp); + } + mutex_unlock(&all_wp_mutex); +} + +int ksw_watch_init(void) +{ + int ret; + + ret = ksw_watch_alloc(); + if (ret <= 0) + return -EBUSY; + + + return 0; +} + +void ksw_watch_exit(void) +{ + ksw_watch_free(); +} -- 2.43.0