From mboxrd@z Thu Jan 1 00:00:00 1970 From: Martin Mokrejs Subject: Re: [PATCH] i2c: i801: fix memleak on probe error Date: Mon, 23 Dec 2013 11:51:12 +0100 Message-ID: <52B815A0.1060609@fold.natur.cuni.cz> References: <20130123174204.00463f98@endymion.delvare> <1387791578-1372-1-git-send-email-lekensteyn@gmail.com> <4657870.yOE66qJqIC@al> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <4657870.yOE66qJqIC@al> Sender: linux-i2c-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Peter Wu , Jean Delvare Cc: linux-i2c-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-Id: linux-i2c@vger.kernel.org Thanks for the note, was just compiling a new 3.10.24 kernel to test it. ;-) So far just booted an old 3.9 kernel and after plugging in an external USB3 drive I got the message, just to be sure I am still able to reproduce the error and that I have the right .config in the running kernel. Will wait for another fix instead. Martin Peter Wu wrote: > 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: >> > >