Re: [PATCH v7 2/2] usb: gadget: udc: core: Prevent soft_connect_store() race

From: kernel test robot
Date: Thu Jun 08 2023 - 19:21:02 EST


Hi Badhri,

kernel test robot noticed the following build warnings:

[auto build test WARNING on d37537a1f7cf09e304fe7993cb5e732534a0fb22]

url: https://github.com/intel-lab-lkp/linux/commits/Badhri-Jagan-Sridharan/usb-gadget-udc-core-Prevent-soft_connect_store-race/20230609-044555
base: d37537a1f7cf09e304fe7993cb5e732534a0fb22
patch link: https://lore.kernel.org/r/20230608204517.105396-2-badhri%40google.com
patch subject: [PATCH v7 2/2] usb: gadget: udc: core: Prevent soft_connect_store() race
config: hexagon-randconfig-r015-20230608 (https://download.01.org/0day-ci/archive/20230609/202306090722.opxFRfOO-lkp@xxxxxxxxx/config)
compiler: clang version 17.0.0 (https://github.com/llvm/llvm-project.git 4a5ac14ee968ff0ad5d2cc1ffa0299048db4c88a)
reproduce (this is a W=1 build):
mkdir -p ~/bin
wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
chmod +x ~/bin/make.cross
git checkout d37537a1f7cf09e304fe7993cb5e732534a0fb22
b4 shazam https://lore.kernel.org/r/20230608204517.105396-2-badhri@xxxxxxxxxx
# save the config file
mkdir build_dir && cp config build_dir/.config
COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang ~/bin/make.cross W=1 O=build_dir ARCH=hexagon olddefconfig
COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang ~/bin/make.cross W=1 O=build_dir ARCH=hexagon SHELL=/bin/bash drivers/usb/gadget/udc/

If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@xxxxxxxxx>
| Closes: https://lore.kernel.org/oe-kbuild-all/202306090722.opxFRfOO-lkp@xxxxxxxxx/

All warnings (new ones prefixed by >>):

In file included from drivers/usb/gadget/udc/core.c:17:
In file included from include/linux/dma-mapping.h:10:
In file included from include/linux/scatterlist.h:9:
In file included from arch/hexagon/include/asm/io.h:334:
include/asm-generic/io.h:547:31: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
547 | val = __raw_readb(PCI_IOBASE + addr);
| ~~~~~~~~~~ ^
include/asm-generic/io.h:560:61: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
560 | val = __le16_to_cpu((__le16 __force)__raw_readw(PCI_IOBASE + addr));
| ~~~~~~~~~~ ^
include/uapi/linux/byteorder/little_endian.h:37:51: note: expanded from macro '__le16_to_cpu'
37 | #define __le16_to_cpu(x) ((__force __u16)(__le16)(x))
| ^
In file included from drivers/usb/gadget/udc/core.c:17:
In file included from include/linux/dma-mapping.h:10:
In file included from include/linux/scatterlist.h:9:
In file included from arch/hexagon/include/asm/io.h:334:
include/asm-generic/io.h:573:61: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
573 | val = __le32_to_cpu((__le32 __force)__raw_readl(PCI_IOBASE + addr));
| ~~~~~~~~~~ ^
include/uapi/linux/byteorder/little_endian.h:35:51: note: expanded from macro '__le32_to_cpu'
35 | #define __le32_to_cpu(x) ((__force __u32)(__le32)(x))
| ^
In file included from drivers/usb/gadget/udc/core.c:17:
In file included from include/linux/dma-mapping.h:10:
In file included from include/linux/scatterlist.h:9:
In file included from arch/hexagon/include/asm/io.h:334:
include/asm-generic/io.h:584:33: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
584 | __raw_writeb(value, PCI_IOBASE + addr);
| ~~~~~~~~~~ ^
include/asm-generic/io.h:594:59: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
594 | __raw_writew((u16 __force)cpu_to_le16(value), PCI_IOBASE + addr);
| ~~~~~~~~~~ ^
include/asm-generic/io.h:604:59: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
604 | __raw_writel((u32 __force)cpu_to_le32(value), PCI_IOBASE + addr);
| ~~~~~~~~~~ ^
>> drivers/usb/gadget/udc/core.c:850:1: warning: unused label 'out' [-Wunused-label]
850 | out:
| ^~~~
851 | trace_usb_gadget_deactivate(gadget, ret);
drivers/usb/gadget/udc/core.c:886:1: warning: unused label 'out' [-Wunused-label]
886 | out:
| ^~~~
887 | trace_usb_gadget_activate(gadget, ret);
8 warnings generated.


vim +/out +850 drivers/usb/gadget/udc/core.c

5a8d651a2bde01 drivers/usb/gadget/udc/udc-core.c Felipe Balbi 2016-05-31 815
5a8d651a2bde01 drivers/usb/gadget/udc/udc-core.c Felipe Balbi 2016-05-31 816 /**
5a8d651a2bde01 drivers/usb/gadget/udc/udc-core.c Felipe Balbi 2016-05-31 817 * usb_gadget_deactivate - deactivate function which is not ready to work
5a8d651a2bde01 drivers/usb/gadget/udc/udc-core.c Felipe Balbi 2016-05-31 818 * @gadget: the peripheral being deactivated
5a8d651a2bde01 drivers/usb/gadget/udc/udc-core.c Felipe Balbi 2016-05-31 819 *
5a8d651a2bde01 drivers/usb/gadget/udc/udc-core.c Felipe Balbi 2016-05-31 820 * This routine may be used during the gadget driver bind() call to prevent
5a8d651a2bde01 drivers/usb/gadget/udc/udc-core.c Felipe Balbi 2016-05-31 821 * the peripheral from ever being visible to the USB host, unless later
5a8d651a2bde01 drivers/usb/gadget/udc/udc-core.c Felipe Balbi 2016-05-31 822 * usb_gadget_activate() is called. For example, user mode components may
5a8d651a2bde01 drivers/usb/gadget/udc/udc-core.c Felipe Balbi 2016-05-31 823 * need to be activated before the system can talk to hosts.
5a8d651a2bde01 drivers/usb/gadget/udc/udc-core.c Felipe Balbi 2016-05-31 824 *
5a8d651a2bde01 drivers/usb/gadget/udc/udc-core.c Felipe Balbi 2016-05-31 825 * Returns zero on success, else negative errno.
5a8d651a2bde01 drivers/usb/gadget/udc/udc-core.c Felipe Balbi 2016-05-31 826 */
5a8d651a2bde01 drivers/usb/gadget/udc/udc-core.c Felipe Balbi 2016-05-31 827 int usb_gadget_deactivate(struct usb_gadget *gadget)
5a8d651a2bde01 drivers/usb/gadget/udc/udc-core.c Felipe Balbi 2016-05-31 828 {
5e42d710a108c2 drivers/usb/gadget/udc/core.c Felipe Balbi 2016-05-31 829 int ret = 0;
5a8d651a2bde01 drivers/usb/gadget/udc/udc-core.c Felipe Balbi 2016-05-31 830
bfc8a68e3289a9 drivers/usb/gadget/udc/core.c Badhri Jagan Sridharan 2023-06-08 831 mutex_lock(&gadget->udc->connect_lock);
5a8d651a2bde01 drivers/usb/gadget/udc/udc-core.c Felipe Balbi 2016-05-31 832 if (gadget->deactivated)
bfc8a68e3289a9 drivers/usb/gadget/udc/core.c Badhri Jagan Sridharan 2023-06-08 833 goto unlock;
5a8d651a2bde01 drivers/usb/gadget/udc/udc-core.c Felipe Balbi 2016-05-31 834
5a8d651a2bde01 drivers/usb/gadget/udc/udc-core.c Felipe Balbi 2016-05-31 835 if (gadget->connected) {
bfc8a68e3289a9 drivers/usb/gadget/udc/core.c Badhri Jagan Sridharan 2023-06-08 836 ret = usb_gadget_disconnect_locked(gadget);
5a8d651a2bde01 drivers/usb/gadget/udc/udc-core.c Felipe Balbi 2016-05-31 837 if (ret)
bfc8a68e3289a9 drivers/usb/gadget/udc/core.c Badhri Jagan Sridharan 2023-06-08 838 goto unlock;
5e42d710a108c2 drivers/usb/gadget/udc/core.c Felipe Balbi 2016-05-31 839
5a8d651a2bde01 drivers/usb/gadget/udc/udc-core.c Felipe Balbi 2016-05-31 840 /*
5a8d651a2bde01 drivers/usb/gadget/udc/udc-core.c Felipe Balbi 2016-05-31 841 * If gadget was being connected before deactivation, we want
5a8d651a2bde01 drivers/usb/gadget/udc/udc-core.c Felipe Balbi 2016-05-31 842 * to reconnect it in usb_gadget_activate().
5a8d651a2bde01 drivers/usb/gadget/udc/udc-core.c Felipe Balbi 2016-05-31 843 */
5a8d651a2bde01 drivers/usb/gadget/udc/udc-core.c Felipe Balbi 2016-05-31 844 gadget->connected = true;
5a8d651a2bde01 drivers/usb/gadget/udc/udc-core.c Felipe Balbi 2016-05-31 845 }
5a8d651a2bde01 drivers/usb/gadget/udc/udc-core.c Felipe Balbi 2016-05-31 846 gadget->deactivated = true;
5a8d651a2bde01 drivers/usb/gadget/udc/udc-core.c Felipe Balbi 2016-05-31 847
bfc8a68e3289a9 drivers/usb/gadget/udc/core.c Badhri Jagan Sridharan 2023-06-08 848 unlock:
bfc8a68e3289a9 drivers/usb/gadget/udc/core.c Badhri Jagan Sridharan 2023-06-08 849 mutex_unlock(&gadget->udc->connect_lock);
5e42d710a108c2 drivers/usb/gadget/udc/core.c Felipe Balbi 2016-05-31 @850 out:
5e42d710a108c2 drivers/usb/gadget/udc/core.c Felipe Balbi 2016-05-31 851 trace_usb_gadget_deactivate(gadget, ret);
5e42d710a108c2 drivers/usb/gadget/udc/core.c Felipe Balbi 2016-05-31 852
5e42d710a108c2 drivers/usb/gadget/udc/core.c Felipe Balbi 2016-05-31 853 return ret;
5a8d651a2bde01 drivers/usb/gadget/udc/udc-core.c Felipe Balbi 2016-05-31 854 }
5a8d651a2bde01 drivers/usb/gadget/udc/udc-core.c Felipe Balbi 2016-05-31 855 EXPORT_SYMBOL_GPL(usb_gadget_deactivate);
5a8d651a2bde01 drivers/usb/gadget/udc/udc-core.c Felipe Balbi 2016-05-31 856

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