From mboxrd@z Thu Jan 1 00:00:00 1970 From: Peter Wu Subject: Re: [PATCH] i2c: i801: fix memleak on probe error Date: Mon, 23 Dec 2013 11:43:21 +0100 Message-ID: <4657870.yOE66qJqIC@al> References: <20130123174204.00463f98@endymion.delvare> <1387791578-1372-1-git-send-email-lekensteyn@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7Bit Return-path: In-Reply-To: <1387791578-1372-1-git-send-email-lekensteyn-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org> Sender: linux-i2c-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Jean Delvare Cc: linux-i2c-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, Martin Mokrejs , linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-Id: linux-i2c@vger.kernel.org Nevermind this patch, it does not really fix the memleak because i2c_set_adapdata() calls dev_set_drvdata() which allocates memory. (I must have ran kmemleak too early, right after boot it did not give any warnings, now it does). RFC: what about dropping i2c_set_adapdata() from the probe function and replacing i2c_get_adapdata(adapter) by pci_get_drvdata(adapter->pci_dev) on top of this patch? I am not sure what the purpose is for i2c_set_adapdata, hence this question. Regards, Peter On Monday 23 December 2013 10:39:38 Peter Wu wrote: > The driver-specific data for i801 was only set for the device on > success, that led to a memory leak on error paths (for instance, when > there is a resource conflict with ACPI). (The driver core clears the > driver data (if set) if the probe routine fails). > > Fix it by setting the driver data right after successful memory > allocation, before reaching any error paths. > > References: http://lkml.org/lkml/2013/1/23/191 > Reported-by: Martin Mokrejs > Tested-by: Peter Wu [ACPI conflict error path] > Signed-off-by: Peter Wu > --- > Hi Jean, > > This memleak issue is still present in v3.13-rc4-256-gb7000ad. > From kmemleak: > > unreferenced object 0xffff88022f501a00 (size 256): > comm "systemd-udevd", pid 209, jiffies 4294896115 (age 2872.520s) > hex dump (first 32 bytes): > 00 00 00 00 ad 4e ad de ff ff ff ff 00 00 00 00 .....N.......... > ff ff ff ff ff ff ff ff f4 e2 53 82 ff ff ff ff ..........S..... > backtrace: > [] kmemleak_alloc+0x4e/0xb0 > [] kmem_cache_alloc_trace+0xfa/0x1e0 > [] device_private_init+0x23/0x80 > [] dev_set_drvdata+0x39/0x50 > [] i801_probe+0x59/0x528 [i2c_i801] > [] local_pci_probe+0x45/0xa0 > [] pci_device_probe+0xd9/0x130 > [] driver_probe_device+0x87/0x390 > [] __driver_attach+0x93/0xa0 > [] bus_for_each_dev+0x6b/0xb0 > [] driver_attach+0x1e/0x20 > [] bus_add_driver+0x188/0x260 > [] driver_register+0x64/0xf0 > [] __pci_register_driver+0x60/0x70 > [] 0xffffffffa02990af > [] do_one_initcall+0xf2/0x1a0 > > The dmesg for this laptop also contains a resource conflict message, > just like the reporter (Martin Mokrejs): > > [ 15.409772] ACPI Warning: 0x0000000000001840-0x000000000000185f SystemIO conflicts with Region \_SB_.PCI0.SBUS.SMBI 1 (20131115/utaddress-251) > [ 15.413439] ACPI: If an ACPI driver is available for this device, you should use it instead of the native driver > > With this patch applied on top of almost 3.13-rc5 (v3.13-rc4-256-gb7000ad), > the memleak is gone. > > Regards, > Peter > --- > drivers/i2c/busses/i2c-i801.c | 3 +-- > 1 file changed, 1 insertion(+), 2 deletions(-) > > diff --git a/drivers/i2c/busses/i2c-i801.c b/drivers/i2c/busses/i2c-i801.c > index 737e298..a7096bf 100644 > --- a/drivers/i2c/busses/i2c-i801.c > +++ b/drivers/i2c/busses/i2c-i801.c > @@ -1117,6 +1117,7 @@ static int i801_probe(struct pci_dev *dev, const struct pci_device_id *id) > if (!priv) > return -ENOMEM; > > + pci_set_drvdata(dev, priv); > i2c_set_adapdata(&priv->adapter, priv); > priv->adapter.owner = THIS_MODULE; > priv->adapter.class = i801_get_adapter_class(priv); > @@ -1236,8 +1237,6 @@ static int i801_probe(struct pci_dev *dev, const struct pci_device_id *id) > /* We ignore errors - multiplexing is optional */ > i801_add_mux(priv); > > - pci_set_drvdata(dev, priv); > - > return 0; > > exit_free_irq: >