From nobody Mon Feb 9 10:33:31 2026 Received: from m16.mail.163.com (m16.mail.163.com [117.135.210.5]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 4EF5B205ABE for ; Tue, 4 Mar 2025 14:25:26 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=117.135.210.5 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1741098332; cv=none; b=b+HvRnmTSRgzyS/3++0Ib+V7VURnkC7ZSiCqW06/1mOaDutzIrGyCUViaph0XoPFetDYecV1+Q1yIQvbPhxxFTDHtnepTvsdyIWz1NWYxYqfYi00P4jM9NnZJQx/yDnLPkam5bcSmYQJcklnesCsLmKX6DKmE0yBrpPmdBOouwQ= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1741098332; c=relaxed/simple; bh=uOBnjqVHku8KLjSmIJeN7+CSJV8wIxJlGQYxylA1bhI=; h=From:To:Cc:Subject:Date:Message-Id:MIME-Version; b=l1WxGOKIW2ButvRMWaoSlAxhSUaZXGzp/V7XI1Qj2FCXKbN8iUh+r9+IHZmO2bEmTg9ECLF6zgDO0NZH361049GKuc2i/Nlrfq3RWjoN/uib1KI6YwosNSw7tgbmhG+wyob0wGlNMDcdcK6mrA4pVFL9E/iJABABNp6amn+Ruo8= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=163.com; spf=pass smtp.mailfrom=163.com; dkim=pass (1024-bit key) header.d=163.com header.i=@163.com header.b=caUtKXC2; arc=none smtp.client-ip=117.135.210.5 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=163.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=163.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=163.com header.i=@163.com header.b="caUtKXC2" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=163.com; s=s110527; h=From:Subject:Date:Message-Id:MIME-Version; bh=aKGTU /dlsOYSmJzvx1y1f0+yqOr7O0TlNGte0WRVQTg=; b=caUtKXC2e2ZvYUUboeHae GGalq0s9Fs1NjDxZMkxPplA9J4uhkwNdLIrGJRwGcHMEWdqLfKILq2HW+V3Jn/jQ dci81FlAJ14YAFq9lqrEPnT8nAKdAkjXL/KoG8lkO//qkdOdxZWI5ZSjHT16I3wU 9DIZaPqXY5EnYsXghDOk6E= Received: from zhuxin.hobot.cc (unknown []) by gzga-smtp-mtada-g1-3 (Coremail) with SMTP id _____wDXvwA2DcdnOmUHQQ--.34665S2; Tue, 04 Mar 2025 22:25:00 +0800 (CST) From: Zxyan Zhu To: broonie@kernel.org Cc: gregkh@linuxfoundation.org, rafael@kernel.org, dakr@kernel.org, linux-kernel@vger.kernel.org, Zxyan Zhu Subject: [PATCH v2] regmap: debugfs: Fix name collision without atomic operations Date: Tue, 4 Mar 2025 22:24:52 +0800 Message-Id: <20250304142452.3521828-1-zxyan20@163.com> X-Mailer: git-send-email 2.34.1 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 X-CM-TRANSID: _____wDXvwA2DcdnOmUHQQ--.34665S2 X-Coremail-Antispam: 1Uf129KBjvJXoW7tF1UZFyfJF15AryfWw17Wrg_yoW8Cw47pa 1DGF1Fkws7Jr4rGrWYka18CFySk3929a43A3yru3WF9wnagr43WFsYqFW5tryDWryUXw1U XF45A34UCr1jy3DanT9S1TB71UUUUU7qnTZGkaVYY2UrUUUUjbIjqfuFe4nvWSU5nxnvy2 9KBjDUYxBIdaVFxhVjvjDU0xZFpf9x0piYhF7UUUUU= X-CM-SenderInfo: p201t0isq6il2tof0z/1tbioAUGXmfG+lFLCgADs1 Content-Type: text/plain; charset="utf-8" The `dummy_index` global variable caused debugfs file name conflicts during re-entry, leading to creation failures. Use atomic operations to ensure safe and unique debugfs `dummy%d` naming. Changes since v1: - Replaced atomic_read + atomic_inc with atomic_inc_return. - Added atomic_dec in the error path to maintain index consistency. - Updated the commit message to clarify the fix. Signed-off-by: Zxyan Zhu --- drivers/base/regmap/regmap-debugfs.c | 12 +++++++----- 1 file changed, 7 insertions(+), 5 deletions(-) diff --git a/drivers/base/regmap/regmap-debugfs.c b/drivers/base/regmap/reg= map-debugfs.c index fb84cda92a75..60c8d9a673b8 100644 --- a/drivers/base/regmap/regmap-debugfs.c +++ b/drivers/base/regmap/regmap-debugfs.c @@ -20,7 +20,7 @@ struct regmap_debugfs_node { struct list_head link; }; =20 -static unsigned int dummy_index; +static atomic_t dummy_index =3D ATOMIC_INIT(0); static struct dentry *regmap_debugfs_root; static LIST_HEAD(regmap_debugfs_early_list); static DEFINE_MUTEX(regmap_debugfs_early_lock); @@ -549,6 +549,7 @@ void regmap_debugfs_init(struct regmap *map) struct regmap_range_node *range_node; const char *devname =3D "dummy"; const char *name =3D map->name; + int index; =20 /* * Userspace can initiate reads from the hardware over debugfs. @@ -595,12 +596,13 @@ void regmap_debugfs_init(struct regmap *map) =20 if (!strcmp(name, "dummy")) { kfree(map->debugfs_name); - map->debugfs_name =3D kasprintf(GFP_KERNEL, "dummy%d", - dummy_index); - if (!map->debugfs_name) + index =3D atomic_inc_return(&dummy_index); + map->debugfs_name =3D kasprintf(GFP_KERNEL, "dummy%d", index); + if (!map->debugfs_name) { + atomic_dec(&dummy_index); return; + } name =3D map->debugfs_name; - dummy_index++; } =20 map->debugfs =3D debugfs_create_dir(name, regmap_debugfs_root); --=20 2.34.1