linux-kernel - Re: [PATCH 1/2] pci: host: pci-hyperv: Replace GFP_ATOMIC with GFP_KERNEL in hv_pci

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <20180319083850.tglknmwwybdhahfl@mwanda>
Date:   Mon, 19 Mar 2018 11:38:50 +0300
From:   Dan Carpenter <dan.carpenter@...cle.com>
To:     Jia-Ju Bai <baijiaju1990@...il.com>
Cc:     kys@...rosoft.com, haiyangz@...rosoft.com, sthemmin@...rosoft.com,
        bhelgaas@...gle.com, devel@...uxdriverproject.org,
        linux-kernel@...r.kernel.org, linux-pci@...r.kernel.org
Subject: Re: [PATCH 1/2] pci: host: pci-hyperv: Replace GFP_ATOMIC with
 GFP_KERNEL in hv_pci_onchannelcallback

On Sun, Mar 18, 2018 at 10:53:02PM +0800, Jia-Ju Bai wrote:
> hv_pci_onchannelcallback() is not called in atomic context.
> 
> The call chain ending up at hv_pci_onchannelcallback() is:
> [1] hv_pci_onchannelcallback() <- hv_pci_probe()
> hv_pci_probe() is only set as ".probe" in hv_driver 
> structure "hv_pci_drv".
> 

Your static analysis tool is faulty and apparently so is Smatch.

$ smdb function_ptrs hv_pci_onchannelcallback

Says it can't find a caller.  When I look for function pointers I get:

$ smdb function_ptr hv_pci_onchannelcallback
hv_pci_onchannelcallback =  'hv_pci_onchannelcallback' , 'vmbus_open param 5' , '(struct vmbus_channel)->onchannel_callback' , '__read_once_size param 0'

Anyway the call tree is:

vmbus_chan_sched() <-- takes rcu_read_lock();
-> vmbus_channel_isr()
   -> channel->onchannel_callback() -> which is hv_pci_onchannelcallback()

regards,
dan carpenter