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 77500CAC5A5 for ; Wed, 24 Sep 2025 11:51:49 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id D3BB08E000E; Wed, 24 Sep 2025 07:51:48 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id CEC798E0001; Wed, 24 Sep 2025 07:51:48 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id B67258E000E; Wed, 24 Sep 2025 07:51:48 -0400 (EDT) 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 9F02B8E0001 for ; Wed, 24 Sep 2025 07:51:48 -0400 (EDT) Received: from smtpin03.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay05.hostedemail.com (Postfix) with ESMTP id 53DA35B0D0 for ; Wed, 24 Sep 2025 11:51:48 +0000 (UTC) X-FDA: 83923979496.03.8953B12 Received: from mail-pf1-f174.google.com (mail-pf1-f174.google.com [209.85.210.174]) by imf21.hostedemail.com (Postfix) with ESMTP id 6F3451C000A for ; Wed, 24 Sep 2025 11:51:46 +0000 (UTC) Authentication-Results: imf21.hostedemail.com; dkim=pass header.d=gmail.com header.s=20230601 header.b="KdI0i/g9"; spf=pass (imf21.hostedemail.com: domain of wangjinchao600@gmail.com designates 209.85.210.174 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=1758714706; 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-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=l9dguoBkY6LX1N0DOj75LxFoPgkZue82QF3pLTyVov0=; b=NUnZKW9In2nYZjX4NXIy0twBtMPKrut6rOqFXdFVkWr/HQLi+XFy8nZtOtsXEVqp4Jtli9 j/KLrhAyG6NMNBbUfajk/bJQZyuRiURqHVW8qcoyq3NrbDuDzuDNTxM5Cjza3AtSryoINB 4ZqSp7ZI2NIrsEbhiiDnSxvtcmE+rwI= ARC-Authentication-Results: i=1; imf21.hostedemail.com; dkim=pass header.d=gmail.com header.s=20230601 header.b="KdI0i/g9"; spf=pass (imf21.hostedemail.com: domain of wangjinchao600@gmail.com designates 209.85.210.174 as permitted sender) smtp.mailfrom=wangjinchao600@gmail.com; dmarc=pass (policy=none) header.from=gmail.com ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1758714706; a=rsa-sha256; cv=none; b=4k3mF1Xt77hH0iDtECfRUluthFiZgRqOl2k2M2HCcrlwrqojoqBdUOVLiAUNRCU9o/yZ0+ yzNDH/a8SKm0U0f4uIp5Ks4c9KzN4fDXJj3QOpm0yqTAFhuX8g+pRPzs1wys2LTtVUVzFY UTgl6dP2uVDvBFzoqqBhYfYdt0oNuok= Received: by mail-pf1-f174.google.com with SMTP id d2e1a72fcca58-77f169d8153so4099452b3a.3 for ; Wed, 24 Sep 2025 04:51:46 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20230601; t=1758714705; x=1759319505; darn=kvack.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=l9dguoBkY6LX1N0DOj75LxFoPgkZue82QF3pLTyVov0=; b=KdI0i/g9B2/+t18HDUUrOiGwbjHfjzbckZIAIKQorNUWLf++U8QCRE+IJPoXbThUMg 4pReSjFPbcRm2ONj5O6EZ1S1tZsdZ3Th07tRamH4/RKJDkBugsbNA4/QsOaoP2+HaKIp mrTP6MQtKKUfH8PKcEeV26N29hr0AcgytkuhVRpo5blE8i0di+Rj5SkN49c8xQLcqcb/ siy0uYO16M1dBggh+diXIF7MtkP8ZSOSI8iGGkrOLEtmrTvsXU0xXpwwaEGt4c/08au0 wSevD93TEzBQHmHGfrXxmBhuel9LGGsvZhecX2fMTHeqkSLpISLne9kOvqyVAuA4ULtm Z6Ng== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1758714705; x=1759319505; 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=l9dguoBkY6LX1N0DOj75LxFoPgkZue82QF3pLTyVov0=; b=m5ezKhYIEuJWPpPI39zFJBj3n+Dy0A/immpOqpLnU7hUdr2oMP/lT04zs25P54pI1P 2XENdbLcv9kwgHTTFka/27812ckgrM48NEBQ5yZsx+VNm5J/jlsaXdSoXaewHEXtiKpI FWe/hcm4XruNTUNKB5wljypeUQ3/mMuHzPNQezLmKdgR3AeDlU9A348A95mWS064W8/K PUQYgUCbVB4MWSHQAmHLI3K3ox4ktJ9qdCiq/CTl5oz1DRzX0N8Y/YP7KrZlfO6ldFLa 7YXQ6owfbqYJfviyg1SMYacagrs7Du3BOgNdgX/zkwN72r1Btvb7bD574HMDj67KUfLO t4nw== X-Forwarded-Encrypted: i=1; AJvYcCX8ugEL8afC/a17rcIMT4emsaf1CxZXzx2Fxs8SuORyoRtQTJ0ySQxj+Wpw/q4MZBhJf4neiEuZ9g==@kvack.org X-Gm-Message-State: AOJu0Yy3XNBltxcB7/H1kCa8T3QXyOWqf8KNKl0PKHZkhU8xKUSB75cp U9D4peB4u44JXNyjpInphATknO42NM04Z7ApVG/vYALKxrkralFvp2bW X-Gm-Gg: ASbGncu/+fczCOUWxghzZrIlkpN3MTqLXoC96KSvogNfl9D1BRM1C0HczpCnxKgIT14 wYjlvdFNvbtmOqtxpb2G/Q5rz2j65u7725jp9ZIPTL6BjPVNMWHoeIWgO7GPvSUGLK9hpFB5EwV YDHSRI8d4W+h7EhdLwImSDTM3QH+jmjYelW+ywyXCBIGwFD5X94rtxmHQftVMjQB4gyjWupQeze v0LxWqO6TeYHy8rza6D0eXcBvkC/hR/xyq0A1J4EqLZ2Vj1GW7T/Fv1ph2WYFDIJWy52gGEMd1m HQjp+2J8L9oGSNGL3yt5lvtVwO65x3jb4USG98oc+tycL2yNI0bMnUCKpKcbFmNEWAfMtvWukvC JrSrLgH/sjGv4NoAJ8GrCCdpGMA== X-Google-Smtp-Source: AGHT+IEasneXpiW3mfzS6InuZbVOqKXOEJYnqzt5bTMRV5lm54Ib2pRaVdJ4xzF5Ie29cXcRAIIxXQ== X-Received: by 2002:a05:6a00:228b:b0:77f:50df:df31 with SMTP id d2e1a72fcca58-77f53b0ed0cmr6348588b3a.20.1758714705264; Wed, 24 Sep 2025 04:51:45 -0700 (PDT) Received: from localhost ([23.142.224.65]) by smtp.gmail.com with ESMTPSA id d2e1a72fcca58-77cfc2490dcsm18664494b3a.36.2025.09.24.04.51.44 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 24 Sep 2025 04:51:44 -0700 (PDT) From: Jinchao Wang To: 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 Cc: Jinchao Wang Subject: [PATCH v5 03/23] HWBP: Add modify_wide_hw_breakpoint_local() API Date: Wed, 24 Sep 2025 19:50:46 +0800 Message-ID: <20250924115124.194940-4-wangjinchao600@gmail.com> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20250924115124.194940-1-wangjinchao600@gmail.com> References: <20250924115124.194940-1-wangjinchao600@gmail.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Stat-Signature: pne4q319eeuao96354amufi5rgtsy8p8 X-Rspam-User: X-Rspamd-Queue-Id: 6F3451C000A X-Rspamd-Server: rspam04 X-HE-Tag: 1758714706-316612 X-HE-Meta: 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 hmgDGrZo 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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: From: "Masami Hiramatsu (Google)" Add modify_wide_hw_breakpoint_local() arch-wide interface which allows hwbp users to update watch address on-line. This is available if the arch supports CONFIG_HAVE_REINSTALL_HW_BREAKPOINT. Note that this allows to change the type only for compatible types, because it does not release and reserve the hwbp slot based on type. For instance, you can not change HW_BREAKPOINT_W to HW_BREAKPOINT_X. Signed-off-by: Masami Hiramatsu (Google) --- arch/Kconfig | 10 ++++++++++ arch/x86/Kconfig | 1 + include/linux/hw_breakpoint.h | 6 ++++++ kernel/events/hw_breakpoint.c | 37 +++++++++++++++++++++++++++++++++++ 4 files changed, 54 insertions(+) diff --git a/arch/Kconfig b/arch/Kconfig index d1b4ffd6e085..e4787fc814df 100644 --- a/arch/Kconfig +++ b/arch/Kconfig @@ -418,6 +418,16 @@ config HAVE_MIXED_BREAKPOINTS_REGS Select this option if your arch implements breakpoints under the latter fashion. +config HAVE_REINSTALL_HW_BREAKPOINT + bool + depends on HAVE_HW_BREAKPOINT + help + Depending on the arch implementation of hardware breakpoints, + some of them are able to update the breakpoint configuration + without release and reserve the hardware breakpoint register. + What configuration is able to update depends on hardware and + software implementation. + config HAVE_USER_RETURN_NOTIFIER bool diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig index 52c8910ba2ef..4ea313ef3e82 100644 --- a/arch/x86/Kconfig +++ b/arch/x86/Kconfig @@ -247,6 +247,7 @@ config X86 select HAVE_FUNCTION_TRACER select HAVE_GCC_PLUGINS select HAVE_HW_BREAKPOINT + select HAVE_REINSTALL_HW_BREAKPOINT select HAVE_IOREMAP_PROT select HAVE_IRQ_EXIT_ON_IRQ_STACK if X86_64 select HAVE_IRQ_TIME_ACCOUNTING diff --git a/include/linux/hw_breakpoint.h b/include/linux/hw_breakpoint.h index db199d653dd1..ea373f2587f8 100644 --- a/include/linux/hw_breakpoint.h +++ b/include/linux/hw_breakpoint.h @@ -81,6 +81,9 @@ register_wide_hw_breakpoint(struct perf_event_attr *attr, perf_overflow_handler_t triggered, void *context); +extern int modify_wide_hw_breakpoint_local(struct perf_event *bp, + struct perf_event_attr *attr); + extern int register_perf_hw_breakpoint(struct perf_event *bp); extern void unregister_hw_breakpoint(struct perf_event *bp); extern void unregister_wide_hw_breakpoint(struct perf_event * __percpu *cpu_events); @@ -124,6 +127,9 @@ register_wide_hw_breakpoint(struct perf_event_attr *attr, perf_overflow_handler_t triggered, void *context) { return NULL; } static inline int +modify_wide_hw_breakpoint_local(struct perf_event *bp, + struct perf_event_attr *attr) { return -ENOSYS; } +static inline int register_perf_hw_breakpoint(struct perf_event *bp) { return -ENOSYS; } static inline void unregister_hw_breakpoint(struct perf_event *bp) { } static inline void diff --git a/kernel/events/hw_breakpoint.c b/kernel/events/hw_breakpoint.c index 8ec2cb688903..5ee1522a99c9 100644 --- a/kernel/events/hw_breakpoint.c +++ b/kernel/events/hw_breakpoint.c @@ -887,6 +887,43 @@ void unregister_wide_hw_breakpoint(struct perf_event * __percpu *cpu_events) } EXPORT_SYMBOL_GPL(unregister_wide_hw_breakpoint); +/** + * modify_wide_hw_breakpoint_local - update breakpoint config for local CPU + * @bp: the hwbp perf event for this CPU + * @attr: the new attribute for @bp + * + * This does not release and reserve the slot of a HWBP; it just reuses the + * current slot on local CPU. So the users must update the other CPUs by + * themselves. + * Also, since this does not release/reserve the slot, this can not change the + * type to incompatible type of the HWBP. + * Return err if attr is invalid or the CPU fails to update debug register + * for new @attr. + */ +#ifdef CONFIG_HAVE_REINSTALL_HW_BREAKPOINT +int modify_wide_hw_breakpoint_local(struct perf_event *bp, + struct perf_event_attr *attr) +{ + int ret; + + if (find_slot_idx(bp->attr.bp_type) != find_slot_idx(attr->bp_type)) + return -EINVAL; + + ret = hw_breakpoint_arch_parse(bp, attr, counter_arch_bp(bp)); + if (ret) + return ret; + + return arch_reinstall_hw_breakpoint(bp); +} +#else +int modify_wide_hw_breakpoint_local(struct perf_event *bp, + struct perf_event_attr *attr) +{ + return -EOPNOTSUPP; +} +#endif +EXPORT_SYMBOL_GPL(modify_wide_hw_breakpoint_local); + /** * hw_breakpoint_is_used - check if breakpoints are currently used * -- 2.43.0