From nobody Fri Oct 3 21:00:02 2025 Received: from galois.linutronix.de (Galois.linutronix.de [193.142.43.55]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id E24242ECD13; Mon, 25 Aug 2025 10:25:11 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=193.142.43.55 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1756117513; cv=none; b=j2QjmYc/OUpP4idRx97vQ7h8+b4dCRazS4wrGc6VJXLDqh/Z1PPNSrZrQ2WmI1P217pDjL4xTYdU0qUXKTqhjSEU0bsJvUJ0TFbNAj3L7SfVzGPNlvT6mYtv68zljT09Dm72Kit4Uiz+XEMqOaVhRIsCqNg1SqEP/zKcZGB73iQ= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1756117513; c=relaxed/simple; bh=oQU45IFyIDhyK9CmiC3KJigsu0sONMEtKjRziiVe7BM=; h=Date:From:To:Subject:Cc:In-Reply-To:References:MIME-Version: Message-ID:Content-Type; b=jLiklavf1BJ5ur3o4i2IDUDsaG9NgnAo2mmv29RjDRUYGXW9ovyBHUjJScRo4HRS9hQ38+blf38C7RV5sQbr3/0IGSla4V/4Lc2P5cnkl0IIBha0EIbgVfRDEp/sC+/i4ieyTRyfBoeiioEcpwU4wbHkNqXrZVZqlNUh1cb3C88= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linutronix.de; spf=pass smtp.mailfrom=linutronix.de; dkim=pass (2048-bit key) header.d=linutronix.de header.i=@linutronix.de header.b=VrLc2baW; dkim=permerror (0-bit key) header.d=linutronix.de header.i=@linutronix.de header.b=bjOQBmwW; arc=none smtp.client-ip=193.142.43.55 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linutronix.de Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linutronix.de Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=linutronix.de header.i=@linutronix.de header.b="VrLc2baW"; dkim=permerror (0-bit key) header.d=linutronix.de header.i=@linutronix.de header.b="bjOQBmwW" Date: Mon, 25 Aug 2025 10:25:09 -0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1756117510; h=from:from:sender:sender:reply-to:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=ex7lyt7Yu/2zY52yOjMi5p39cbf+JiAHbHdUL6P6cHw=; b=VrLc2baWEILjukvY2LwWt8Flnnv7MzxaIt1n65ILXIdx1rDgkZcSatywR5aFPt+Dl4NmM5 d0CB9eLfYYT/XDTZiH46j+ANmLPhY1Xlj92xi05JGkNS5DzImTMEnHLh/h3qf6e/TzOgom eXlHvTy9S+aEYuBeBqqpWW90MWgpWHYWfttcc/3NqkoMrGAEJ+NHzBx8VST5w4FkV+ltv6 OtuLFq/v5quZTWzOKoCGrXXo8Ncv1CWvEQ3PkGQEHMV+bZVoEGBMIAu74L29thK1pfjfpX AAk6G/EuCN943YL5ATokgTbP2yuh0QSPCU8n9zvsE8wprRowniEeKDYyedLsaQ== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1756117510; h=from:from:sender:sender:reply-to:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=ex7lyt7Yu/2zY52yOjMi5p39cbf+JiAHbHdUL6P6cHw=; b=bjOQBmwWAllKPJ977wBromREUSLkJJb3UVHq7VJWHXZWM8RT8+nuevYMW61UfgKItDTJPp 2pxJ8gCyz4YuOvAA== From: "tip-bot2 for Jiri Olsa" Sender: tip-bot2@linutronix.de Reply-to: linux-kernel@vger.kernel.org To: linux-tip-commits@vger.kernel.org Subject: [tip: perf/core] uprobes: Remove breakpoint in unapply_uprobe under mmap_write_lock Cc: Jiri Olsa , "Peter Zijlstra (Intel)" , Andrii Nakryiko , "Masami Hiramatsu (Google)" , Oleg Nesterov , x86@kernel.org, linux-kernel@vger.kernel.org In-Reply-To: <20250720112133.244369-2-jolsa@kernel.org> References: <20250720112133.244369-2-jolsa@kernel.org> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Message-ID: <175611750907.1420.16310655013957778625.tip-bot2@tip-bot2> Robot-ID: Robot-Unsubscribe: Contact to get blacklisted from these emails Precedence: bulk Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable The following commit has been merged into the perf/core branch of tip: Commit-ID: 7769cb177b23142b83f22abd06e492cc25157893 Gitweb: https://git.kernel.org/tip/7769cb177b23142b83f22abd06e492cc2= 5157893 Author: Jiri Olsa AuthorDate: Sun, 20 Jul 2025 13:21:11 +02:00 Committer: Peter Zijlstra CommitterDate: Thu, 21 Aug 2025 20:09:18 +02:00 uprobes: Remove breakpoint in unapply_uprobe under mmap_write_lock Currently unapply_uprobe takes mmap_read_lock, but it might call remove_breakpoint which eventually changes user pages. Current code writes either breakpoint or original instruction, so it can go away with read lock as explained in here [1]. But with the upcoming change that writes multiple instructions on the probed address we need to ensure that any update to mm's pages is exclusive. [1] https://lore.kernel.org/all/20240710140045.GA1084@redhat.com/ Signed-off-by: Jiri Olsa Signed-off-by: Peter Zijlstra (Intel) Acked-by: Andrii Nakryiko Acked-by: Masami Hiramatsu (Google) Acked-by: Oleg Nesterov Link: https://lore.kernel.org/r/20250720112133.244369-2-jolsa@kernel.org --- kernel/events/uprobes.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/kernel/events/uprobes.c b/kernel/events/uprobes.c index 7ca1940..1cbfe3c 100644 --- a/kernel/events/uprobes.c +++ b/kernel/events/uprobes.c @@ -482,7 +482,7 @@ remap: * @opcode_vaddr: the virtual address to store the opcode. * @opcode: opcode to be written at @opcode_vaddr. * - * Called with mm->mmap_lock held for read or write. + * Called with mm->mmap_lock held for write. * Return 0 (success) or a negative errno. */ int uprobe_write_opcode(struct arch_uprobe *auprobe, struct vm_area_struct= *vma, @@ -1463,7 +1463,7 @@ static int unapply_uprobe(struct uprobe *uprobe, stru= ct mm_struct *mm) struct vm_area_struct *vma; int err =3D 0; =20 - mmap_read_lock(mm); + mmap_write_lock(mm); for_each_vma(vmi, vma) { unsigned long vaddr; loff_t offset; @@ -1480,7 +1480,7 @@ static int unapply_uprobe(struct uprobe *uprobe, stru= ct mm_struct *mm) vaddr =3D offset_to_vaddr(vma, uprobe->offset); err |=3D remove_breakpoint(uprobe, vma, vaddr); } - mmap_read_unlock(mm); + mmap_write_unlock(mm); =20 return err; }