From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-pg1-f175.google.com (mail-pg1-f175.google.com [209.85.215.175]) (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 505552E370E for ; Fri, 12 Sep 2025 10:12:09 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.215.175 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1757671931; cv=none; b=UKey5mgoqnAD/b29+8fMXO/RR5ALqLDbsYNjkttPSuTLdEb5NPxkFtyDz0Hkrkf9+NVPkxU7/W6LyoqJBeCJwJcgZMhzpg2jUucNEqUxEysoXE/pTUXvaUeZnQ0iuQkbbFYbXxkUFFht59YS5fivzGZEYMwMO5xcF9hQsOiMEHI= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1757671931; c=relaxed/simple; bh=zbmepUv5MhWdm0b+QCOGN6KW75Q1eP0IAhJLHBVpxMk=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=atugirIzN+TfO9WnDfqb6wK7ZwsGIqM4dv58qiDC+W55eKgNROhu17IvxRmmQIAc1EsDqNHaymjFdC3NB6ARNAOlWgbwOgcIz8RDWXAlYvBTsSQhpUAYQgXjZUIir0YO8iEZaMx84PYu24jdakssEfs2QBt+jh9cvRTZjuP1VwU= 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=YakZc8qj; arc=none smtp.client-ip=209.85.215.175 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="YakZc8qj" Received: by mail-pg1-f175.google.com with SMTP id 41be03b00d2f7-b54a74f9150so907072a12.0 for ; Fri, 12 Sep 2025 03:12:09 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20230601; t=1757671928; x=1758276728; 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=E07gf3+EHiFZ+TUqDdqlrvhEU6rgl4o/YSp2RBqLkNw=; b=YakZc8qjiI5W3v1TlAAhn8+1Plm5tgFZOiqF3oCD/+e/EGnQTFLw29HcsI5+H11mB0 0IcUx80Rnu8LmfXuXJTuQxJzdMekYny+xacwcwnNQt3UMzvplDxo9/9ZFoGrSdqw5kq2 UmShVTk9Dc8bN7CpYpd4DtjNiS5fgrCequmUBYd1kkyYaucetD3vMqmXuJCYA1A2UcL3 VNsVZuuGEgTPDWZaCstIlbFmkdP3dtxRhV7qPcQzsmJ7TJGhTK4FOaWW5PUqNeHhmeHh 5nBKAzR7In2AxXSQKe5GTf9Y8B5FvrlmgNU0arxWMzRgfzPQurGDY7sXjWg+r4HYnebP EAuA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1757671928; x=1758276728; 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=E07gf3+EHiFZ+TUqDdqlrvhEU6rgl4o/YSp2RBqLkNw=; b=xOOx5EhMXDEJjjFaMULSI4xmOiA5H+DEqkDOcuX/9YuhyeHNUOy97SXQkZfwFrRucO DbzeW3RohfQ7ZNjcckZGL6qpbc9M1MmjfNX83+OwC2emNYhpVNiM/RFVLnjzZAXN2IzG CYkdnQ3XPXl3WPOl3GE8kDs6Lhh9orFm4eCAG2OpZWqB3nJXUmoglibQMKnjS7vMm7Mm 2W/vMgCzhrikGGC7NXDK8iCeu5+xBULlbMcdMHynQ4FSzlBg4x3IGe6boYudBobfuJJ/ JmiTJVAigDMP/sA1Pi0Hx8CBTWGEzWXI8EeZ5tcJoszhfUAnFIEhTI+drDbvcYvNf8pq K8EA== X-Forwarded-Encrypted: i=1; AJvYcCVd6tvK8upMCFpFOc6VpDBL5QZAHcb9MOjeLtY9CzJAO8xjeJ4OpQ9ExL8to1EZP6Q4hoXfZtErdGRLyWEefWrKccI=@vger.kernel.org X-Gm-Message-State: AOJu0Yyx6FfGIus0HpE27HI/EILFTObd+EQIIcS0PflK8H9YzXRCvpQT JytYg1QyJpnwijRpaZbFOfGJwOxZyBkRStS+r9trdPC59+Ey5m+8SKlK X-Gm-Gg: ASbGncsf81iQa672hkJYcXYiI04+oy0Y+Ac7HHx4tZz8ObifXtCQsJE4+cb5TAzBlCC +8dG2JF1m+TnvXIABRzNVy10wE2/sYulz0HnhSahPpSFGMbtPcpdBp+srs3KRENizNz9mL5KaRl mKbfugeyoHi6gnXUcH00X0BtAaGO+ZOPKldcmLs9ldBdBYciUdC5O1RohCS5jL4RqxbJlZDN+nS 9zFK1t9IqZltJmj4PdZALogbFEF4QVWjgwleYNgE8pzCXJLPx+3AItDFs5d3IvTJzHy9/Mt6VRv fr0AJ6bVCYQ8hgto31V04c9YwQgiL8qdsV6F/l0Qwdbz4mU5ui+/g3/Bk1wjNRy5arV8SrtnF+J QiVtP7hLy7UZPZZGIw2ZKdV/8PMjcdYzG5n0ZEHA= X-Google-Smtp-Source: AGHT+IGs/ObotIuyczkZdqAXxWrWykSxCXKo0dzFjl5HuAQGOzaywRYcIXz6zrznumJ6ZW1Xtjh7JA== X-Received: by 2002:a17:903:32c4:b0:258:f033:3ff1 with SMTP id d9443c01a7336-25d242f314bmr32759845ad.12.1757671928125; Fri, 12 Sep 2025 03:12:08 -0700 (PDT) Received: from localhost ([185.49.34.62]) by smtp.gmail.com with ESMTPSA id d9443c01a7336-25c37293fd4sm44061135ad.38.2025.09.12.03.12.06 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 12 Sep 2025 03:12:07 -0700 (PDT) From: Jinchao Wang To: Andrew Morton , Masami Hiramatsu , Peter Zijlstra , Mike Rapoport , Alexander Potapenko , 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 v4 02/21] x86/hw_breakpoint: Add arch_reinstall_hw_breakpoint Date: Fri, 12 Sep 2025 18:11:12 +0800 Message-ID: <20250912101145.465708-3-wangjinchao600@gmail.com> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20250912101145.465708-1-wangjinchao600@gmail.com> References: <20250912101145.465708-1-wangjinchao600@gmail.com> Precedence: bulk X-Mailing-List: linux-trace-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit The new arch_reinstall_hw_breakpoint() function can be used in an atomic context, unlike the more expensive free and re-allocation path. This allows callers to efficiently re-establish an existing breakpoint. Signed-off-by: Jinchao Wang --- arch/x86/include/asm/hw_breakpoint.h | 2 ++ arch/x86/kernel/hw_breakpoint.c | 9 +++++++++ 2 files changed, 11 insertions(+) diff --git a/arch/x86/include/asm/hw_breakpoint.h b/arch/x86/include/asm/hw_breakpoint.h index aa6adac6c3a2..c22cc4e87fc5 100644 --- a/arch/x86/include/asm/hw_breakpoint.h +++ b/arch/x86/include/asm/hw_breakpoint.h @@ -21,6 +21,7 @@ struct arch_hw_breakpoint { enum bp_slot_action { BP_SLOT_ACTION_INSTALL, + BP_SLOT_ACTION_REINSTALL, BP_SLOT_ACTION_UNINSTALL, }; @@ -65,6 +66,7 @@ extern int hw_breakpoint_exceptions_notify(struct notifier_block *unused, int arch_install_hw_breakpoint(struct perf_event *bp); +int arch_reinstall_hw_breakpoint(struct perf_event *bp); void arch_uninstall_hw_breakpoint(struct perf_event *bp); void hw_breakpoint_pmu_read(struct perf_event *bp); void hw_breakpoint_pmu_unthrottle(struct perf_event *bp); diff --git a/arch/x86/kernel/hw_breakpoint.c b/arch/x86/kernel/hw_breakpoint.c index 3658ace4bd8d..29c9369264d4 100644 --- a/arch/x86/kernel/hw_breakpoint.c +++ b/arch/x86/kernel/hw_breakpoint.c @@ -99,6 +99,10 @@ static int manage_bp_slot(struct perf_event *bp, enum bp_slot_action action) old_bp = NULL; new_bp = bp; break; + case BP_SLOT_ACTION_REINSTALL: + old_bp = bp; + new_bp = bp; + break; case BP_SLOT_ACTION_UNINSTALL: old_bp = bp; new_bp = NULL; @@ -187,6 +191,11 @@ int arch_install_hw_breakpoint(struct perf_event *bp) return arch_manage_bp(bp, BP_SLOT_ACTION_INSTALL); } +int arch_reinstall_hw_breakpoint(struct perf_event *bp) +{ + return arch_manage_bp(bp, BP_SLOT_ACTION_REINSTALL); +} + void arch_uninstall_hw_breakpoint(struct perf_event *bp) { arch_manage_bp(bp, BP_SLOT_ACTION_UNINSTALL); -- 2.43.0