From nobody Thu Oct 2 02:13:30 2025 Received: from mail-pg1-f169.google.com (mail-pg1-f169.google.com [209.85.215.169]) (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 EE909242D6A for ; Tue, 30 Sep 2025 02:44:56 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.215.169 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1759200299; cv=none; b=m0xodeAJ8H6BNYrE5UVQM52XE1FE/QQSN69EaUTeF6dzEx+pHuQGJigOKJoZvYpz7PfJv63cjqTxMBQ0/Qs8Klgh+V6WSzVCM6h2F8viL29wds4RU37BG4+h4HoNsMMSXLVKkyao/Y1UPWbiz2AuvxZUvFg/eYEFnsw1tLpjlN0= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1759200299; c=relaxed/simple; bh=nvDFxA5+kzzGy254IQd/07joD3bGnycuza2xxZ+JqIE=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=WHxXEy8oUHzpJXDaXjpgIiUrXJCw3+PTJ3i0aTxcXD0q/syvKnDGj9uC9ihNK866VURmEauqhqwJ6FI722OhUAhH+RjJNHVbzWsjO7Ju48jhnWnrj7SCl3y+a/Zb2qBDi7wrBn0okJ4fIEX/qnuimr82CP5aFDugYO1RRuTcsUE= 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=mJ76OFhY; arc=none smtp.client-ip=209.85.215.169 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="mJ76OFhY" Received: by mail-pg1-f169.google.com with SMTP id 41be03b00d2f7-b55562f3130so3778041a12.2 for ; Mon, 29 Sep 2025 19:44:56 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20230601; t=1759200296; x=1759805096; 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=mJ76OFhYyoEVI1m6MmA90KWiXh0cWoZ+eVR32ITQ1dl8xZlM6ELU4o/auxNRHvKf+F bck2JmEnVSLQwXMsluy+z9wGgo7KYB4mpwaFKr40+Rx1A9e2NQWFraw+b9RKDtaq2Iuv rdG36KAv5nA5sQ4JyE9FNpdfQ2dOgkPHUOSF1rHLLbSM3Vg1RZ1op3VY7jff+zz+S08C ai0MrjNUcAGMf6daJwhHFMLozqdK0fDvfb58SuNv8pYJwXFeqf5ztAMxXslYiPZC9UZc soNL6a5z4FBLavJhyi1WdWifEkRayE29joiC9LrjHAL7KIq6TjxdZty/D6+IF3xKelJ0 /DSQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1759200296; x=1759805096; 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=JoL12CKrjyOuA+S6HIWy5jIvtywjoGv2WJ+D0nHmGQl8Fa+uQROfPaI+co8KCipT1t iNC4m1W0VDK8gKoKK6qli835YobacJku1si4SMmrjDAZSaZHYy9sI567a4pBrLUlYm8K yXVUtORuu3+jLJnFAJZq/CgbgKOcSsJfkGxpgMO74MESYqg980UO4kbvgMAveTJsWtO/ /zCIjpFA7Mi539pK9Id0FhkRsJDvHoGOrSZ3Rt7+6sY1nn+KL8MYi4BfmQyuvvRc+/iI Aijs3jmMKxC1TU8WJpa78vTVoIY5Hd/nec0Pt8UG44Xz915Akr36Q/+viS9vL5AbKQza xAAg== X-Forwarded-Encrypted: i=1; AJvYcCVepKhd4OiZ1MrVdhf9L1XuyCf98bTLRJFfJhM2w/9SQAlzs76vuVXEz1jKnaGdxGLU3y92Sj7suSA14CY=@vger.kernel.org X-Gm-Message-State: AOJu0Yxmdfxnwk08rX8c9Ivfc7AaIGMjc0ovrwfmMQLkGRKq4ezy1dZc IoAC6P00YC8gJykOGXaDrY4hQbS6WbfvtS50+p1iD32jFXkS61WJJONM X-Gm-Gg: ASbGncu+wr8uhcyyp01Gnqmv9qO6yLwjAxKhHl/T6Ewsj4dCgqbTIeULoFHXjEsQCQH ebZVTYsKVulSSu8k1SIb6I+i8jkfcnvP1tAJBBLyR6FQfWDx7A+hkTkfWJXnwoQt7qXUJ84v5OG eKi1Z1FOWuxByGjFA+quUEI7Y3tq7PpSrJImvQUrZSFRv5v103dVzrU3aN62DeAAkCIJNZSJPpC 9J6QxrPnBMZ6N/zx+wcbW5IIoqFEW5T4nWnqx9+E49da3gM3xBp49I8Uc1w52FJUUfq+yXj63hU Kno1HqftUJ+DHO7Xjfd09pxSbv+kFlwj39nlZRWAJxWMyL994KvD4uzYsIbUsZN04HKNeEWfXct iNWXARiUx3g0Na/sMR7bDxVHDzE/cGFiGG0tm1ZLrwEJa6UJzHUarR33K7BZPbNT/FA== X-Google-Smtp-Source: AGHT+IH29Thtb5D6YkJakO5t9BTsEfGfbuz5XXYNk5kI0v7F6fpI1sv279aA08He56DkC5ZrjPjoLw== X-Received: by 2002:a17:902:e54a:b0:270:b6d5:f001 with SMTP id d9443c01a7336-27ed4a0d542mr209110885ad.23.1759200295846; Mon, 29 Sep 2025 19:44:55 -0700 (PDT) Received: from localhost ([45.142.167.196]) by smtp.gmail.com with ESMTPSA id d9443c01a7336-27ed69952b3sm145098075ad.96.2025.09.29.19.44.55 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 29 Sep 2025 19:44:55 -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 07/23] mm/ksw: add HWBP pre-allocation Date: Tue, 30 Sep 2025 10:43:28 +0800 Message-ID: <20250930024402.1043776-8-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: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" 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 =20 +#include +#include +#include #include =20 #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); =20 +/* 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("=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D KStackWatch: Caught stack corrupti= on =3D=3D=3D=3D=3D=3D=3D\n"); + pr_err("config %s\n", ksw_get_config()->user_input); + dump_stack(); + pr_err("=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D KStackW= atch End =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D\n"); + + if (panic_on_catch) + panic("Stack corruption detected"); +} + +static int ksw_watch_alloc(void) +{ + int max_watch =3D ksw_get_config()->max_watch; + struct ksw_watchpoint *wp; + int success =3D 0; + int ret; + + init_llist_head(&free_wp_list); + + //max_watch=3D0 means at most + while (!max_watch || success < max_watch) { + wp =3D kzalloc(sizeof(*wp), GFP_KERNEL); + if (!wp) + return success > 0 ? success : -EINVAL; + + hw_breakpoint_init(&wp->attr); + wp->attr.bp_addr =3D (ulong)&holder; + wp->attr.bp_len =3D sizeof(ulong); + wp->attr.bp_type =3D HW_BREAKPOINT_W; + wp->event =3D register_wide_hw_breakpoint(&wp->attr, + ksw_watch_handler, wp); + if (IS_ERR((void *)wp->event)) { + ret =3D 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 =3D ksw_watch_alloc(); + if (ret <=3D 0) + return -EBUSY; + + + return 0; +} + +void ksw_watch_exit(void) +{ + ksw_watch_free(); +} --=20 2.43.0