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 E147DCCFA13 for ; Mon, 10 Nov 2025 16:37:16 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 4B5778E0040; Mon, 10 Nov 2025 11:37:16 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 48D278E0003; Mon, 10 Nov 2025 11:37:16 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 37C378E0040; Mon, 10 Nov 2025 11:37:16 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0016.hostedemail.com [216.40.44.16]) by kanga.kvack.org (Postfix) with ESMTP id 250658E0003 for ; Mon, 10 Nov 2025 11:37:16 -0500 (EST) Received: from smtpin24.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay02.hostedemail.com (Postfix) with ESMTP id DE32313890B for ; Mon, 10 Nov 2025 16:37:15 +0000 (UTC) X-FDA: 84095252430.24.C76B7C3 Received: from mail-pf1-f176.google.com (mail-pf1-f176.google.com [209.85.210.176]) by imf01.hostedemail.com (Postfix) with ESMTP id 06ABB4000E for ; Mon, 10 Nov 2025 16:37:13 +0000 (UTC) Authentication-Results: imf01.hostedemail.com; dkim=pass header.d=gmail.com header.s=20230601 header.b=f8vz7NFh; spf=pass (imf01.hostedemail.com: domain of wangjinchao600@gmail.com designates 209.85.210.176 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=1762792634; 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=OfQWKEWM8M6Sp/kqVVWTo1Q3rJtTZ9aAiY0lp7l1vgw=; b=VM3JgSKQM2P9jhkXnHHb7XITsOxbPftW3peVqm/Hc+DdjVCRPg1BYv3AiaQ7jnqrjI4jwr nUg/bKpVhasnP4HCio6s5pfVGqNSybU1eEffRtETZRNHNntV16LeksFJN4SK55EDiNCmv4 fvQ45PTspbLHqGkz5TU/jcEqr3rMIGk= ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1762792634; a=rsa-sha256; cv=none; b=aOHhP1ndsgqwFyj7qlXwyZgdVIgBU+T8ZgCuTUIkrVjMxAXB+aslr3psjWr9j8z++Ru8ld jZ0tAAu1ZKmZjPu4pfBbIhufegBsnJPHphBzaK7PU7avfQIjr0OssqjEEfP2sxxyMecQ5L 7aK7IuMJT9B1YCNMl67TxhGgji5hxkY= ARC-Authentication-Results: i=1; imf01.hostedemail.com; dkim=pass header.d=gmail.com header.s=20230601 header.b=f8vz7NFh; spf=pass (imf01.hostedemail.com: domain of wangjinchao600@gmail.com designates 209.85.210.176 as permitted sender) smtp.mailfrom=wangjinchao600@gmail.com; dmarc=pass (policy=none) header.from=gmail.com Received: by mail-pf1-f176.google.com with SMTP id d2e1a72fcca58-7ad1cd0db3bso2413034b3a.1 for ; Mon, 10 Nov 2025 08:37:13 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20230601; t=1762792633; x=1763397433; 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=OfQWKEWM8M6Sp/kqVVWTo1Q3rJtTZ9aAiY0lp7l1vgw=; b=f8vz7NFhKNePabMSewsASX2NJDrNea+zyqP5Z8AOOcHsSnbxbnXIwOpmzKBntm90BA E3AT3lAaplJQMaZpzocww874bpH7nTBW0CZqNukkIsuhpip8JzBQX13oSIusHsog3QeM zsm5IJGeU5dThfCFs1gqpkkGLaFw5MbYWzRVSFMt1WGxDA2hkofPtQCKj9D+eo+bOvJc TGFGnSwY+KFeKoxPbpTAIK4XpZNi9kBZk3m8OQbCWytnF2UhbpLZj04dLr51UWlEuKPa r1KWmm+E1ayX0PoNhQmB/TQ/sOKvDXJF1kafRj5prQ3xkfks1LG12Hdmpz91xX//SlQl tgvw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1762792633; x=1763397433; 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=OfQWKEWM8M6Sp/kqVVWTo1Q3rJtTZ9aAiY0lp7l1vgw=; b=smbFbFCI4Eu+SqhgOREINVMBsjEtf54ZY7nBU/x4IiIK4U2UWgKfRVeZIxUVC80HZ9 L1JyiDQ1oCnkPxyDhiJSoIKEtviafFlHUyAQzoSLQJuzxbd2PH3nwMcWwUJ2l+8b3JXL xvfoahXpym74BRypz5dYEIlV/CHnapD+fA7ZmtYLKG9mC4+wgcRNadvdMk5wOIo3iJGK JQBY94AjXhqU1/2/fqD1+qksIcx2ewmUWpa3tkEvYeSU8McmjaWc2SZ628lctGqtC/03 CP7QKq4f40XSx6C3x9zL2G6E1i0gDE6/Pz74RAZaffyQV/lv57/T9+233y93+0CBGKdc NRkg== X-Forwarded-Encrypted: i=1; AJvYcCWWooGormPLL7vgxK10Xj/Fz/K0ioPIa66gDN0/fGw6rrZlcpOfNoxc8VUzfrC702Xb/RsTYaU5PA==@kvack.org X-Gm-Message-State: AOJu0Yxps1IbqJwUedG8mKBa8g7zaj+liZkbJVP1Qd1do8OucAGS1v5h YroCuiT1Z8/Le7qtLiccBhBSGK9s8k9n5/sl6zlehtqxkS0sS+ga7YAS X-Gm-Gg: ASbGncsB8q8+YRlqXbo2FjlSQBh0fdbt2y1FvTk26NEslxxmLOdZCZIATScvRIaeZrO w9+9WlK9IAAMrXyRdjU4BGXZ8HGUk746enku00eWZqB3t5/eFyHB72mmX4vKkvDr5zyh9XpxeTX onXkkbBTMs/a2n3wBP2lwUNO5ljgdW4EazkinJIsVO1bFkOe7NvOYwbQ7LnNL+0IyLUzRSOjwEd jQxRnupNVEir4UZs8oWRVx+ry/8avEhTFWyJAOT+72aEQKYbTNkxn9gUGD2KtPGOyfrKvn+Eaih Vq0OpWL0WEl7fM1jn0K3/+ewjI+QCqAUKup4PB5Ma5X26z7Xg0aBw2JjWO1l3KKfMxOqMoB/0T9 G3TVyYlnIg7eDle7cqprZXu9RUJFHmi802SG73Ea7Y+7es0IamiND43w+Ezel6SYcm7s9b/8VNP bUZjed/ZWMA2qI9jir09YgBQ== X-Google-Smtp-Source: AGHT+IHERHOBNDq56+F7J5rW3t9aw2ypcpu6OwOvG+DJGpa6Vz1ez0X0Vnm2nUUH/tERSMimjoOmZw== X-Received: by 2002:a05:6a20:5483:b0:342:873d:7e62 with SMTP id adf61e73a8af0-353a2d42046mr10346355637.29.1762792632699; Mon, 10 Nov 2025 08:37:12 -0800 (PST) Received: from localhost ([103.88.46.62]) by smtp.gmail.com with ESMTPSA id d2e1a72fcca58-7b0cc17784bsm12559855b3a.47.2025.11.10.08.37.11 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 10 Nov 2025 08:37:12 -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 07/27] mm/ksw: add HWBP pre-allocation Date: Tue, 11 Nov 2025 00:36:02 +0800 Message-ID: <20251110163634.3686676-8-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-Rspamd-Server: rspam12 X-Rspam-User: X-Rspamd-Queue-Id: 06ABB4000E X-Stat-Signature: 8uysxw4icu4p4d7ju9kffzotsndedkc6 X-HE-Tag: 1762792633-851767 X-HE-Meta: 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 eXWULPes 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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: 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 --- include/linux/kstackwatch.h | 13 ++++++ mm/kstackwatch/watch.c | 93 +++++++++++++++++++++++++++++++++++++ 2 files changed, 106 insertions(+) diff --git a/include/linux/kstackwatch.h b/include/linux/kstackwatch.h index ada5ac64190c..eb9f2b4f2109 100644 --- a/include/linux/kstackwatch.h +++ b/include/linux/kstackwatch.h @@ -2,6 +2,9 @@ #ifndef _KSTACKWATCH_H #define _KSTACKWATCH_H +#include +#include +#include #include #define MAX_CONFIG_STR_LEN 128 @@ -38,4 +41,14 @@ 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..4947eac32c61 100644 --- a/mm/kstackwatch/watch.c +++ b/mm/kstackwatch/watch.c @@ -1 +1,94 @@ // SPDX-License-Identifier: GPL-2.0 +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt + +#include +#include +#include +#include +#include +#include + +static LLIST_HEAD(free_wp_list); +static LIST_HEAD(all_wp_list); +static DEFINE_MUTEX(all_wp_mutex); + +static ulong holder; + +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 (ksw_get_config()->panic_hit) + 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