From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-ej1-f45.google.com (mail-ej1-f45.google.com [209.85.218.45]) (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 5A92433B97A for ; Thu, 11 Jun 2026 10:14:52 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.218.45 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1781172894; cv=none; b=JASiGIqvAM7Jc+HSr4sFMU2bUGN3CIa95wzwpt/wV51MuXmqSIRTzctyyTKvBbBA96+SnsS6poDoMbDbCry+QC2bI/3SGw5YwxeBOXiFW+Gfm4jN+BD0iT4EkKAAK13vbiP34vnKh/ENnCqOZn1qCIOITEzfe4QPRZI/AbR1CfU= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1781172894; c=relaxed/simple; bh=9eZNdwPNfhUP5WBjs6gZQh1KrkEXUZ82qFh22EZeSes=; h=From:To:Cc:Subject:In-Reply-To:References:Date:Message-ID: MIME-Version:Content-Type; b=a1jKRH3QUNndCXquYHpCyzLptxGZPMLGq3qrUw0nqCZq9WiBJi7TTXPPHiRf7c2tRNC7RukQ+uNA6NIWjDRCsRRX4hLq6XcCYvBGUQT7CKYrdHMKKfI7lwyswfqlskdQAV+fF9wICYvkHVdgd2SRtvACgODNq/wzVQjhwykXpeg= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=fail (p=none dis=none) header.from=mina86.com; spf=pass smtp.mailfrom=gmail.com; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b=ibPJU6bb; arc=none smtp.client-ip=209.85.218.45 Authentication-Results: smtp.subspace.kernel.org; dmarc=fail (p=none dis=none) header.from=mina86.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="ibPJU6bb" Received: by mail-ej1-f45.google.com with SMTP id a640c23a62f3a-beeba001887so1039290766b.3 for ; Thu, 11 Jun 2026 03:14:52 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20251104; t=1781172891; x=1781777691; darn=vger.kernel.org; h=content-transfer-encoding:mime-version:message-id:date:references :in-reply-to:subject:cc:to:from:sender:from:to:cc:subject:date :message-id:reply-to; bh=ZLVj8HPnjQUPxr42XEggbTLDi52RglLjMQW50aq25TE=; b=ibPJU6bb3DAVPz1Kyvi2HLUag1BIJq8yMEbuhR57tYz5FoEk0TbZYmXqAqNbZZpqFX XE0o1XNT542PbEKiidKZcClUkNR3jqIwIpldnn6sqY0Opso81qcgvD0zIDDxM3DXODn7 hMTDCqUpW3jC3KJU+IEQGEeuL4IxdkkyrrxlKvfsVd7fgGQo0pXQr3K2kh8ueYr4mu/1 auogk/HY+HxY4I4lXKWMR3ufGL6uk2HcjFup537a53HG5q5yy4DtH0XZorQfJrULRsIW akTLyacvXp6uRoJGxswOOc05lfNhL7JTBvxoQ1ozD0Nr7bOwYAgBhGeJEgfaHDSCVpur 1dbQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1781172891; x=1781777691; h=content-transfer-encoding:mime-version:message-id:date:references :in-reply-to:subject:cc:to:from:sender:x-gm-gg:x-gm-message-state :from:to:cc:subject:date:message-id:reply-to; bh=ZLVj8HPnjQUPxr42XEggbTLDi52RglLjMQW50aq25TE=; b=O82wKdQVcXP0iJTRikTgeVPB4VuyTJy5OF+N0tkOsOtXB3ctKrT7fs79ryXWI0XhMK OVvS3v4Iez4XTJm/0NvVq1n1U6jdnmaTn5mkCWgS/ZIKC8tfFlkmYRJDkT4aq+fr/sA7 XyAtE05/HZNbS3CKTGsraZdz5PgksUWmq+2pTAxOCS1fxcRBOYnQmeGCoq69n/TuYNiB rhUWx/qsK7YGvbDI0Hrt83FqmQWAo+QX6pUPBV0z/nNemHtT1uBX5g1VY3MGlrcJIQ+h JfEePagbev/YvdJewyF+RrxKK2vkNqKclKf7zKVIejEet1ju2WaDQvJ83P2YxmLP/if3 uOxA== X-Forwarded-Encrypted: i=1; AFNElJ/wbi6yWddJ1DbYyqoIOOop3wqh/S1RYVYwYXwU/XrCtnWN3VEn1EkS8d5RZgEfq1C5fnV7gFRowalh62U=@vger.kernel.org X-Gm-Message-State: AOJu0YxRjwjFEx+BjqeXWCEXHBhvo6F8gdoUUjv53JShFt5ORhjHr1CI bInk6oMWKCcyz4a7pqAa6a8tZLTOWMmz+Cr4OGxh/x6VWZmy0qsUkhtbRX+gthr6aSE= X-Gm-Gg: Acq92OFgguWAY8gAnAa4pomB5EQIBoODjPXGKin/uGzDwcEc5IVl8MXTHKouNIJDn99 UoIjKZdb/dnwEvQTPNDnQAzwxopQxaHklc6jx8w80H3vYJZdvqfy+ClmokaKK7K1LkwV/pa8GHu m4kXIZGQfOksAFc6hZ5Him2u4PELvNnh2VuaAhR6tOuRSOBSo82+k/RT7J/ie+9SS7y2aWIR/uD Q+bzib/JftE/tF57F5zpPkZyEAPmuNe7jTWfC+3s/KRqztUVub8v6rY3lxGMaHr3A17JA0W2+t2 q14dC304MDPKwvu9y+QTTEZ3HZBaUhA/SEnX083y7J3lPHO/rEQvxC8RaUyVw3p76CL7U6ih3Fz NlsvfluIg7OiG69yQxYOVz+b0Ms3jlaMdpjaHXUmaY+3nw0dxD7JR8MYzYL3xjr0aYF2hskUC5I WS0DZPxJSTeBFYW1E2Ayxp9VyXokTRcyBkTWp/3p2ktlNnNujppLdSu/lRBTeQ X-Received: by 2002:a17:907:9689:b0:bef:d3a1:5065 with SMTP id a640c23a62f3a-bfc863dffeemr91864566b.18.1781172890398; Thu, 11 Jun 2026 03:14:50 -0700 (PDT) Received: from erwin (109241130011.warszawa.vectranet.pl. [109.241.130.11]) by smtp.gmail.com with ESMTPSA id a640c23a62f3a-bfcb6785ef3sm44632866b.59.2026.06.11.03.14.49 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 11 Jun 2026 03:14:49 -0700 (PDT) Sender: =?UTF-8?Q?Micha=C5=82_Nazarewicz?= From: =?utf-8?Q?Micha=C5=82?= Nazarewicz To: Tyler Baker , Greg Kroah-Hartman , Robert Baldyga , Felipe Balbi Cc: Tyler Baker , stable@vger.kernel.org, Loic Poulain , Dmitry Baryshkov , Srinivas Kandagatla , linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] usb: gadget: f_fs: initialize reset_work at allocation time In-Reply-To: <20260609193635.2284430-1-tyler.baker@oss.qualcomm.com> References: <20260609193635.2284430-1-tyler.baker@oss.qualcomm.com> Date: Thu, 11 Jun 2026 12:14:48 +0200 Message-ID: Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable On Tue, Jun 09 2026, Tyler Baker wrote: > ffs_fs_kill_sb() unconditionally calls cancel_work_sync() on > ffs->reset_work when a functionfs instance is unmounted: > > ffs_data_reset(ffs); > cancel_work_sync(&ffs->reset_work); > > However ffs->reset_work is only ever initialized via INIT_WORK() in > ffs_func_set_alt() and ffs_func_disable(), and only on the > FFS_DEACTIVATED path. That state is reached solely by ffs_data_closed() > when the instance is mounted with the "no_disconnect" option, so for the > common case (no "no_disconnect", or mounted and unmounted without ever > being deactivated) reset_work is never initialized. > > ffs_data_new() allocates the ffs_data with kzalloc_obj() and does not > initialize reset_work, and ffs_data_reset()/ffs_data_clear() do not touch > it either, so reset_work.func is left NULL. cancel_work_sync() on such a > work then trips the WARN_ON(!work->func) guard in __flush_work(): > > WARNING: kernel/workqueue.c:4301 at __flush_work+0x330/0x360, CPU#3: um= ount > Call trace: > __flush_work > cancel_work_sync > ffs_fs_kill_sb [usb_f_fs] > deactivate_locked_super > deactivate_super > cleanup_mnt > __cleanup_mnt > task_work_run > exit_to_user_mode_loop > el0_svc > > On older kernels cancel_work_sync() on a zero-initialized work struct was > a silent no-op, which hid the missing initialization. > > Initialize reset_work once in ffs_data_new() so it is always valid for > the lifetime of the ffs_data, and drop the now-redundant INIT_WORK() > calls from the two deactivation paths. > > Fixes: 18d6b32fca38 ("usb: gadget: f_fs: add "no_disconnect" mode") > Cc: stable@vger.kernel.org > Signed-off-by: Tyler Baker > Cc: Loic Poulain > Cc: Dmitry Baryshkov > Cc: Srinivas Kandagatla Acked-by: Micha=C5=82 Nazarewicz > --- > drivers/usb/gadget/function/f_fs.c | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > > diff --git a/drivers/usb/gadget/function/f_fs.c b/drivers/usb/gadget/func= tion/f_fs.c > index 75912ce6ab55..1ee21e29ef73 100644 > --- a/drivers/usb/gadget/function/f_fs.c > +++ b/drivers/usb/gadget/function/f_fs.c > @@ -288,6 +288,7 @@ static int ffs_acquire_dev(const char *dev_name, stru= ct ffs_data *ffs_data); > static void ffs_release_dev(struct ffs_dev *ffs_dev); > static int ffs_ready(struct ffs_data *ffs); > static void ffs_closed(struct ffs_data *ffs); > +static void ffs_reset_work(struct work_struct *work); >=20=20 > /* Misc helper functions ***********************************************= *****/ >=20=20 > @@ -2221,6 +2222,7 @@ static struct ffs_data *ffs_data_new(const char *de= v_name) > init_waitqueue_head(&ffs->ev.waitq); > init_waitqueue_head(&ffs->wait); > init_completion(&ffs->ep0req_completion); > + INIT_WORK(&ffs->reset_work, ffs_reset_work); >=20=20 > /* XXX REVISIT need to update it in some places, or do we? */ > ffs->ev.can_stall =3D 1; > @@ -3775,7 +3777,6 @@ static int ffs_func_set_alt(struct usb_function *f, > if (ffs->state =3D=3D FFS_DEACTIVATED) { > ffs->state =3D FFS_CLOSING; > spin_unlock_irqrestore(&ffs->eps_lock, flags); > - INIT_WORK(&ffs->reset_work, ffs_reset_work); > schedule_work(&ffs->reset_work); > return -ENODEV; > } > @@ -3806,7 +3807,6 @@ static void ffs_func_disable(struct usb_function *f) > if (ffs->state =3D=3D FFS_DEACTIVATED) { > ffs->state =3D FFS_CLOSING; > spin_unlock_irqrestore(&ffs->eps_lock, flags); > - INIT_WORK(&ffs->reset_work, ffs_reset_work); > schedule_work(&ffs->reset_work); > return; > } --=20 Best regards =E3=83=9F=E3=83=8F=E3=82=A6 =E2=80=9C=F0=9D=93=B6=F0=9D=93=B2=F0=9D=93=B7= =F0=9D=93=AA86=E2=80=9D =E3=83=8A=E3=82=B6=E3=83=AC=E3=83=B4=E3=82=A3=E3=83= =84 =C2=ABIf at first you don=E2=80=99t succeed, give up skydiving=C2=BB