From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 5F4EA2F26 for ; Tue, 8 Feb 2022 09:33:07 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 6E60DC004E1; Tue, 8 Feb 2022 09:33:06 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1644312787; bh=FhxF+wItARpZEpojfEM3m80n83PqP7keXml5yW7Krh8=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=jcVAU0JycApzdCpf3F+CSz4y7JYsNl4IY4HAVuudcq3QsQ7YSFwkO2iUK6AL5sy02 7SjB+HEMp+BXorBndR6oyC1l611CmK8mf/PFWHZE2aLrvl9db5DMRVw+B5llmBoA59 bNZg685EYovI5MtvZDxBmTXx80qsrDQipFm6IX54= Date: Tue, 8 Feb 2022 10:33:04 +0100 From: Greg Kroah-Hartman To: "Fabio M. De Francesco" Cc: Larry Finger , Phillip Potter , linux-staging@lists.linux.dev, linux-kernel@vger.kernel.org Subject: Re: [PATCH] staging: r8188eu: Use kzalloc() with GFP_ATOMIC in atomic context Message-ID: References: <20220206225943.7848-1-fmdefrancesco@gmail.com> Precedence: bulk X-Mailing-List: linux-staging@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20220206225943.7848-1-fmdefrancesco@gmail.com> On Sun, Feb 06, 2022 at 11:59:43PM +0100, Fabio M. De Francesco wrote: > Use the GFP_ATOMIC flag of kzalloc() with two memory allocation in > rtw_set_key(). This function is called while holding spinlocks and with > disabled bottom halves, therefore it is not allowed to sleep. With the > GFP_ATOMIC type flag, the allocation is high priority and cannot sleep. > > This issue is detected by Smatch which emits the following warning: > drivers/staging/r8188eu/core/rtw_pwrctrl.c:79 ips_leave() warn: sleeping in atomic context > drivers/staging/r8188eu/core/rtw_pwrctrl.c:81 ips_leave() warn: sleeping in atomic context > > The calls chain (in reverse order) is the following: > > rtw_set_key() > -> ips_leave() > -> -> rtw_pwr_wakeup() > -> -> -> rtw_set_802_11_disassociate() > > The disabilitation of bottom halves and the acquisition of a spinlock is in > rtw_set_802_11_disassociate(). > > After the changes, the post-commit hook output the following messages: > > CHECK: Prefer kzalloc(sizeof(*pcmd)...) over kzalloc(sizeof(struct cmd_obj)...) > + pcmd = kzalloc(sizeof(struct cmd_obj), GFP_ATOMIC); > > CHECK: Prefer kzalloc(sizeof(*psetkeyparm)...) over kzalloc(sizeof(struct setkey_parm)...) > + psetkeyparm = kzalloc(sizeof(struct setkey_parm), GFP_ATOMIC). > > According to the above "CHECK[S]", use the preferred style in the first > kzalloc(). > > Fixes: 79f712ea994d ("staging: r8188eu: Remove wrappers for kalloc() and kzalloc()") > Fixes: 15865124feed ("staging: r8188eu: introduce new core dir for RTL8188eu driver") > Signed-off-by: Fabio M. De Francesco > --- > drivers/staging/r8188eu/core/rtw_mlme.c | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > > diff --git a/drivers/staging/r8188eu/core/rtw_mlme.c b/drivers/staging/r8188eu/core/rtw_mlme.c > index 038bddc361c3..860835e29b79 100644 > --- a/drivers/staging/r8188eu/core/rtw_mlme.c > +++ b/drivers/staging/r8188eu/core/rtw_mlme.c > @@ -1600,12 +1600,12 @@ int rtw_set_key(struct adapter *adapter, struct security_priv *psecuritypriv, in > struct mlme_priv *pmlmepriv = &adapter->mlmepriv; > int res = _SUCCESS; > > - pcmd = kzalloc(sizeof(struct cmd_obj), GFP_KERNEL); > + pcmd = kzalloc(sizeof(*pcmd), GFP_ATOMIC); > if (!pcmd) { > res = _FAIL; /* try again */ > goto exit; > } > - psetkeyparm = kzalloc(sizeof(struct setkey_parm), GFP_KERNEL); > + psetkeyparm = kzalloc(sizeof(*psetkeyparm), GFP_ATOMIC); You are making two different changes here. Please do the first patch to change the sizeof() change to fix up checkpatch, and then the second one for the GFP_ATOMIC change so that if there is a problem with either of them we can only revert the offending change. thanks, greg k-h