| Message ID | 20230608204517.105396-2-badhri@google.com (mailing list archive) |
|---|---|
| State | Superseded |
| Headers | show |
| Series | [v7,1/2] usb: gadget: udc: core: Offload usb_udc_vbus_handler processing | expand |
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@intel.com/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@google.com
# 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@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202306090722.opxFRfOO-lkp@intel.com/
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
Removed the unused out labels reported by test in v8. Regards, Badhri On Thu, Jun 8, 2023 at 4:20 PM kernel test robot <lkp@intel.com> wrote: > > 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@intel.com/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@google.com > # 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@intel.com> > | Closes: https://lore.kernel.org/oe-kbuild-all/202306090722.opxFRfOO-lkp@intel.com/ > > 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 > > -- > 0-DAY CI Kernel Test Service > https://github.com/intel/lkp-tests/wiki
diff --git a/drivers/usb/gadget/udc/core.c b/drivers/usb/gadget/udc/core.c index d2e4f78c53e3..2549717c1446 100644 --- a/drivers/usb/gadget/udc/core.c +++ b/drivers/usb/gadget/udc/core.c @@ -40,6 +40,11 @@ static const struct bus_type gadget_bus_type; * @allow_connect: Indicates whether UDC is allowed to be pulled up. * Set/cleared by gadget_(un)bind_driver() after gadget driver is bound or * unbound. + * @connect_lock: protects udc->started, gadget->connect, + * gadget->allow_connect and gadget->deactivate. The routines + * usb_gadget_connect_locked(), usb_gadget_disconnect_locked(), + * usb_udc_connect_control_locked(), usb_gadget_udc_start_locked() and + * usb_gadget_udc_stop_locked() are called with this lock held. * * This represents the internal data structure which is used by the UDC-class * to hold information about udc driver and gadget together. @@ -53,6 +58,7 @@ struct usb_udc { bool started; bool allow_connect; struct work_struct vbus_work; + struct mutex connect_lock; }; static struct class *udc_class; @@ -692,17 +698,8 @@ int usb_gadget_vbus_disconnect(struct usb_gadget *gadget) } EXPORT_SYMBOL_GPL(usb_gadget_vbus_disconnect); -/** - * usb_gadget_connect - software-controlled connect to USB host - * @gadget:the peripheral being connected - * - * Enables the D+ (or potentially D-) pullup. The host will start - * enumerating this gadget when the pullup is active and a VBUS session - * is active (the link is powered). - * - * Returns zero on success, else negative errno. - */ -int usb_gadget_connect(struct usb_gadget *gadget) +static int usb_gadget_connect_locked(struct usb_gadget *gadget) + __must_hold(&gadget->udc->connect_lock) { int ret = 0; @@ -711,10 +708,12 @@ int usb_gadget_connect(struct usb_gadget *gadget) goto out; } - if (gadget->deactivated || !gadget->udc->allow_connect) { + if (gadget->deactivated || !gadget->udc->allow_connect || !gadget->udc->started) { /* - * If gadget is deactivated we only save new state. - * Gadget will be connected automatically after activation. + * If the gadget isn't usable (because it is deactivated, + * unbound, or not yet started), we only save the new state. + * The gadget will be connected automatically when it is + * activated/bound/started. */ gadget->connected = true; goto out; @@ -729,22 +728,31 @@ int usb_gadget_connect(struct usb_gadget *gadget) return ret; } -EXPORT_SYMBOL_GPL(usb_gadget_connect); /** - * usb_gadget_disconnect - software-controlled disconnect from USB host - * @gadget:the peripheral being disconnected - * - * Disables the D+ (or potentially D-) pullup, which the host may see - * as a disconnect (when a VBUS session is active). Not all systems - * support software pullup controls. + * usb_gadget_connect - software-controlled connect to USB host + * @gadget:the peripheral being connected * - * Following a successful disconnect, invoke the ->disconnect() callback - * for the current gadget driver so that UDC drivers don't need to. + * Enables the D+ (or potentially D-) pullup. The host will start + * enumerating this gadget when the pullup is active and a VBUS session + * is active (the link is powered). * * Returns zero on success, else negative errno. */ -int usb_gadget_disconnect(struct usb_gadget *gadget) +int usb_gadget_connect(struct usb_gadget *gadget) +{ + int ret; + + mutex_lock(&gadget->udc->connect_lock); + ret = usb_gadget_connect_locked(gadget); + mutex_unlock(&gadget->udc->connect_lock); + + return ret; +} +EXPORT_SYMBOL_GPL(usb_gadget_connect); + +static int usb_gadget_disconnect_locked(struct usb_gadget *gadget) + __must_hold(&gadget->udc->connect_lock) { int ret = 0; @@ -756,7 +764,7 @@ int usb_gadget_disconnect(struct usb_gadget *gadget) if (!gadget->connected) goto out; - if (gadget->deactivated) { + if (gadget->deactivated || !gadget->udc->started) { /* * If gadget is deactivated we only save new state. * Gadget will stay disconnected after activation. @@ -779,6 +787,30 @@ int usb_gadget_disconnect(struct usb_gadget *gadget) return ret; } + +/** + * usb_gadget_disconnect - software-controlled disconnect from USB host + * @gadget:the peripheral being disconnected + * + * Disables the D+ (or potentially D-) pullup, which the host may see + * as a disconnect (when a VBUS session is active). Not all systems + * support software pullup controls. + * + * Following a successful disconnect, invoke the ->disconnect() callback + * for the current gadget driver so that UDC drivers don't need to. + * + * Returns zero on success, else negative errno. + */ +int usb_gadget_disconnect(struct usb_gadget *gadget) +{ + int ret; + + mutex_lock(&gadget->udc->connect_lock); + ret = usb_gadget_disconnect_locked(gadget); + mutex_unlock(&gadget->udc->connect_lock); + + return ret; +} EXPORT_SYMBOL_GPL(usb_gadget_disconnect); /** @@ -796,13 +828,14 @@ int usb_gadget_deactivate(struct usb_gadget *gadget) { int ret = 0; + mutex_lock(&gadget->udc->connect_lock); if (gadget->deactivated) - goto out; + goto unlock; if (gadget->connected) { - ret = usb_gadget_disconnect(gadget); + ret = usb_gadget_disconnect_locked(gadget); if (ret) - goto out; + goto unlock; /* * If gadget was being connected before deactivation, we want @@ -812,6 +845,8 @@ int usb_gadget_deactivate(struct usb_gadget *gadget) } gadget->deactivated = true; +unlock: + mutex_unlock(&gadget->udc->connect_lock); out: trace_usb_gadget_deactivate(gadget, ret); @@ -832,8 +867,9 @@ int usb_gadget_activate(struct usb_gadget *gadget) { int ret = 0; + mutex_lock(&gadget->udc->connect_lock); if (!gadget->deactivated) - goto out; + goto unlock; gadget->deactivated = false; @@ -842,8 +878,11 @@ int usb_gadget_activate(struct usb_gadget *gadget) * while it was being deactivated, we call usb_gadget_connect(). */ if (gadget->connected) - ret = usb_gadget_connect(gadget); + ret = usb_gadget_connect_locked(gadget); + mutex_unlock(&gadget->udc->connect_lock); +unlock: + mutex_unlock(&gadget->udc->connect_lock); out: trace_usb_gadget_activate(gadget, ret); @@ -1083,19 +1122,22 @@ EXPORT_SYMBOL_GPL(usb_gadget_set_state); /* ------------------------------------------------------------------------- */ -static void usb_udc_connect_control(struct usb_udc *udc) +/* Acquire connect_lock before calling this function. */ +static void usb_udc_connect_control_locked(struct usb_udc *udc) __must_hold(&udc->connect_lock) { if (udc->vbus) - usb_gadget_connect(udc->gadget); + usb_gadget_connect_locked(udc->gadget); else - usb_gadget_disconnect(udc->gadget); + usb_gadget_disconnect_locked(udc->gadget); } static void vbus_event_work(struct work_struct *work) { struct usb_udc *udc = container_of(work, struct usb_udc, vbus_work); - usb_udc_connect_control(udc); + mutex_lock(&udc->connect_lock); + usb_udc_connect_control_locked(udc); + mutex_unlock(&udc->connect_lock); } /** @@ -1144,7 +1186,7 @@ void usb_gadget_udc_reset(struct usb_gadget *gadget, EXPORT_SYMBOL_GPL(usb_gadget_udc_reset); /** - * usb_gadget_udc_start - tells usb device controller to start up + * usb_gadget_udc_start_locked - tells usb device controller to start up * @udc: The UDC to be started * * This call is issued by the UDC Class driver when it's about @@ -1155,8 +1197,11 @@ EXPORT_SYMBOL_GPL(usb_gadget_udc_reset); * necessary to have it powered on. * * Returns zero on success, else negative errno. + * + * Caller should acquire connect_lock before invoking this function. */ -static inline int usb_gadget_udc_start(struct usb_udc *udc) +static inline int usb_gadget_udc_start_locked(struct usb_udc *udc) + __must_hold(&udc->connect_lock) { int ret; @@ -1173,7 +1218,7 @@ static inline int usb_gadget_udc_start(struct usb_udc *udc) } /** - * usb_gadget_udc_stop - tells usb device controller we don't need it anymore + * usb_gadget_udc_stop_locked - tells usb device controller we don't need it anymore * @udc: The UDC to be stopped * * This call is issued by the UDC Class driver after calling @@ -1182,8 +1227,11 @@ static inline int usb_gadget_udc_start(struct usb_udc *udc) * The details are implementation specific, but it can go as * far as powering off UDC completely and disable its data * line pullups. + * + * Caller should acquire connect lock before invoking this function. */ -static inline void usb_gadget_udc_stop(struct usb_udc *udc) +static inline void usb_gadget_udc_stop_locked(struct usb_udc *udc) + __must_hold(&udc->connect_lock) { if (!udc->started) { dev_err(&udc->dev, "UDC had already stopped\n"); @@ -1342,6 +1390,7 @@ int usb_add_gadget(struct usb_gadget *gadget) udc->gadget = gadget; gadget->udc = udc; + mutex_init(&udc->connect_lock); udc->started = false; @@ -1545,12 +1594,16 @@ static int gadget_bind_driver(struct device *dev) if (ret) goto err_bind; - ret = usb_gadget_udc_start(udc); - if (ret) + mutex_lock(&udc->connect_lock); + ret = usb_gadget_udc_start_locked(udc); + if (ret) { + mutex_unlock(&udc->connect_lock); goto err_start; + } usb_gadget_enable_async_callbacks(udc); udc->allow_connect = true; - usb_udc_connect_control(udc); + usb_udc_connect_control_locked(udc); + mutex_unlock(&udc->connect_lock); kobject_uevent(&udc->dev.kobj, KOBJ_CHANGE); return 0; @@ -1583,12 +1636,14 @@ static void gadget_unbind_driver(struct device *dev) udc->allow_connect = false; cancel_work_sync(&udc->vbus_work); - usb_gadget_disconnect(gadget); + mutex_lock(&udc->connect_lock); + usb_gadget_disconnect_locked(gadget); usb_gadget_disable_async_callbacks(udc); if (gadget->irq) synchronize_irq(gadget->irq); udc->driver->unbind(gadget); - usb_gadget_udc_stop(udc); + usb_gadget_udc_stop_locked(udc); + mutex_unlock(&udc->connect_lock); mutex_lock(&udc_lock); driver->is_bound = false; @@ -1674,11 +1729,15 @@ static ssize_t soft_connect_store(struct device *dev, } if (sysfs_streq(buf, "connect")) { - usb_gadget_udc_start(udc); - usb_gadget_connect(udc->gadget); + mutex_lock(&udc->connect_lock); + usb_gadget_udc_start_locked(udc); + usb_gadget_connect_locked(udc->gadget); + mutex_unlock(&udc->connect_lock); } else if (sysfs_streq(buf, "disconnect")) { - usb_gadget_disconnect(udc->gadget); - usb_gadget_udc_stop(udc); + mutex_lock(&udc->connect_lock); + usb_gadget_disconnect_locked(udc->gadget); + usb_gadget_udc_stop_locked(udc); + mutex_unlock(&udc->connect_lock); } else { dev_err(dev, "unsupported command '%s'\n", buf); ret = -EINVAL;
usb_udc_connect_control(), soft_connect_store() and usb_gadget_deactivate() can potentially race against each other to invoke usb_gadget_connect()/usb_gadget_disconnect(). To prevent this, guard udc->started, gadget->allow_connect, gadget->deactivate and gadget->connect with connect_lock so that ->pullup() is only invoked when the gadget is bound, started and not deactivated. The routines usb_gadget_connect_locked(), usb_gadget_disconnect_locked(), usb_udc_connect_control_locked(), usb_gadget_udc_start_locked(), usb_gadget_udc_stop_locked() are called with this lock held. An earlier version of this commit was reverted due to the crash reported in https://lore.kernel.org/all/ZF4BvgsOyoKxdPFF@francesco-nb.int.toradex.com/. commit 16737e78d190 ("usb: gadget: udc: core: Offload usb_udc_vbus_handler processing") addresses the crash reported. Cc: stable@vger.kernel.org Fixes: 628ef0d273a6 ("usb: udc: add usb_udc_vbus_handler") Signed-off-by: Badhri Jagan Sridharan <badhri@google.com> --- v5 is the first version in this series. Changes since v5: ** Fixed up commit message ** Wrapped comments at 76. Changes since v6: ** Address Alan comments around style/presentation. ** Fixed code to acquire ->connect_lock before testing gadget->deactivated. --- drivers/usb/gadget/udc/core.c | 153 +++++++++++++++++++++++----------- 1 file changed, 106 insertions(+), 47 deletions(-)