[kbuild-all] Re: [PATCH v4 1/2] media: rc: new driver for USB-UIRT device

On Fri, Jun 18, 2021 at 06:18:06AM +0800, kernel test robot wrote: > Hi Sean, > > I love your patch! Perhaps something to improve: > > [auto build test WARNING on linuxtv-media/master] > [also build test WARNING on usb-serial/usb-next usb/usb-testing peter.chen-usb/for-usb-next v5.13-rc6 next-20210617] > [If your patch is applied to the wrong git tree, kindly drop us a note. > And when submitting patch, we suggest to use '--base' as documented in > https://git-scm.com/docs/git-format-patch] > > url: https://github.com/0day-ci/linux/commits/Sean-Young/IR-driver-for-USB-UIR... > base: git://linuxtv.org/media_tree.git master > config: powerpc64-randconfig-r012-20210617 (attached as .config) > compiler: clang version 13.0.0 (https://github.com/llvm/llvm-project 64720f57bea6a6bf033feef4a5751ab9c0c3b401) > reproduce (this is a W=1 build): > wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross > chmod +x ~/bin/make.cross > # install powerpc64 cross compiling tool for clang build > # apt-get install binutils-powerpc64-linux-gnu > # https://github.com/0day-ci/linux/commit/17d3a0332baecb0359e05e8ae755478c7... > git remote add linux-review https://github.com/0day-ci/linux > git fetch --no-tags linux-review Sean-Young/IR-driver-for-USB-UIRT-device/20210616-182135 > git checkout 17d3a0332baecb0359e05e8ae755478c7a1a4468 > # save the attached .config to linux build tree > COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross ARCH=powerpc64 > > If you fix the issue, kindly add following tag as appropriate > Reported-by: kernel test robot <lkp(a)intel.com&gt; > > All warnings (new ones prefixed by >>): > > In file included from drivers/media/rc/uirt.c:11: > In file included from include/linux/completion.h:12: > In file included from include/linux/swait.h:5: > In file included from include/linux/list.h:9: > In file included from include/linux/kernel.h:12: > In file included from include/linux/bitops.h:32: > In file included from arch/powerpc/include/asm/bitops.h:62: > arch/powerpc/include/asm/barrier.h:49:9: warning: '__lwsync' macro redefined [-Wmacro-redefined] > #define __lwsync() __asm__ __volatile__ (stringify_in_c(LWSYNC) : : :"memory") > ^ > <built-in>:310:9: note: previous definition is here > #define __lwsync __builtin_ppc_lwsync > ^ >>> drivers/media/rc/uirt.c:639:6: warning: variable 'err' is used uninitialized whenever 'if' condition is true [-Wsometimes-uninitialized] > if (!urb) > ^~~~ > drivers/media/rc/uirt.c:705:9: note: uninitialized use occurs here > return err; This is interesting. clang is right here, there are error paths where err is not initialized. gcc-11.1 does not pick this up for some reason. The error path should be an immediate dominator so it shouldn't be complicated to detect.

I'll send out a v5 with this issue fixed. Sean > ^~~ > drivers/media/rc/uirt.c:639:2: note: remove the 'if' if its condition is always false > if (!urb) > ^~~~~~~~~ > drivers/media/rc/uirt.c:630:6: warning: variable 'err' is used uninitialized whenever 'if' condition is true [-Wsometimes-uninitialized] > if (!urb) > ^~~~ > drivers/media/rc/uirt.c:705:9: note: uninitialized use occurs here > return err; > ^~~ > drivers/media/rc/uirt.c:630:2: note: remove the 'if' if its condition is always false > if (!urb) > ^~~~~~~~~ > drivers/media/rc/uirt.c:626:6: warning: variable 'err' is used uninitialized whenever 'if' condition is true [-Wsometimes-uninitialized] > if (!rc) > ^~~ > drivers/media/rc/uirt.c:705:9: note: uninitialized use occurs here > return err; > ^~~ > drivers/media/rc/uirt.c:626:2: note: remove the 'if' if its condition is always false > if (!rc) > ^~~~~~~~ > drivers/media/rc/uirt.c:622:6: warning: variable 'err' is used uninitialized whenever 'if' condition is true [-Wsometimes-uninitialized] > if (!uirt->out) > ^~~~~~~~~~ > drivers/media/rc/uirt.c:705:9: note: uninitialized use occurs here > return err; > ^~~ > drivers/media/rc/uirt.c:622:2: note: remove the 'if' if its condition is always false > if (!uirt->out) > ^~~~~~~~~~~~~~~ > drivers/media/rc/uirt.c:618:6: warning: variable 'err' is used uninitialized whenever 'if' condition is true [-Wsometimes-uninitialized] > if (!uirt->in) > ^~~~~~~~~ > drivers/media/rc/uirt.c:705:9: note: uninitialized use occurs here > return err; > ^~~ > drivers/media/rc/uirt.c:618:2: note: remove the 'if' if its condition is always false > if (!uirt->in) > ^~~~~~~~~~~~~~ > drivers/media/rc/uirt.c:604:15: note: initialize the variable 'err' to silence this warning > int pipe, err; > ^ > = 0 > 6 warnings generated. > > > vim +639 drivers/media/rc/uirt.c > > 594 > 595 static int uirt_probe(struct usb_interface *intf, > 596 const struct usb_device_id *id) > 597 { > 598 struct usb_device *usbdev = interface_to_usbdev(intf); > 599 struct usb_endpoint_descriptor *ep_in; > 600 struct usb_endpoint_descriptor *ep_out; > 601 struct uirt *uirt; > 602 struct rc_dev *rc; > 603 struct urb *urb; > 604 int pipe, err; > 605 > 606 if (usb_find_common_endpoints(intf->cur_altsetting, &ep_in, &ep_out, NULL, NULL) || > 607 usb_endpoint_maxp(ep_in) != MAX_PACKET || > 608 usb_endpoint_maxp(ep_out) != MAX_PACKET) { > 609 dev_err(&intf->dev, "required endpoints not found\n"); > 610 return -ENODEV; > 611 } > 612 > 613 uirt = kzalloc(sizeof(*uirt), GFP_KERNEL); > 614 if (!uirt) > 615 return -ENOMEM; > 616 > 617 uirt->in = kmalloc(MAX_PACKET, GFP_KERNEL); > 618 if (!uirt->in) > 619 goto free_uirt; > 620 > 621 uirt->out = kmalloc(MAX_PACKET, GFP_KERNEL); > 622 if (!uirt->out) > 623 goto free_uirt; > 624 > 625 rc = rc_allocate_device(RC_DRIVER_IR_RAW); > 626 if (!rc) > 627 goto free_uirt; > 628 > 629 urb = usb_alloc_urb(0, GFP_KERNEL); > 630 if (!urb) > 631 goto free_rcdev; > 632 > 633 pipe = usb_rcvbulkpipe(usbdev, ep_in->bEndpointAddress); > 634 usb_fill_bulk_urb(urb, usbdev, pipe, uirt->in, MAX_PACKET, > 635 uirt_in_callback, uirt); > 636 uirt->urb_in = urb; > 637 > 638 urb = usb_alloc_urb(0, GFP_KERNEL); > > 639 if (!urb) > 640 goto free_rcdev; > 641 > 642 pipe = usb_sndbulkpipe(usbdev, ep_out->bEndpointAddress); > 643 usb_fill_bulk_urb(urb, usbdev, pipe, uirt->out, MAX_PACKET, > 644 uirt_out_callback, uirt); > 645 > 646 uirt->dev = &intf->dev; > 647 uirt->usbdev = usbdev; > 648 uirt->rc = rc; > 649 uirt->urb_out = urb; > 650 uirt->rx_state = RX_STATE_INTERSPACE_HIGH; > 651 > 652 err = usb_submit_urb(uirt->urb_in, GFP_KERNEL); > 653 if (err != 0) { > 654 dev_err(uirt->dev, "failed to submit read urb: %d\n", err); > 655 goto free_rcdev; > 656 } > 657 > 658 err = init_ftdi(usbdev); > 659 if (err) { > 660 dev_err(uirt->dev, "failed to setup ftdi: %d\n", err); > 661 goto kill_urbs; > 662 } > 663 > 664 err = uirt_setup(uirt); > 665 if (err) > 666 goto kill_urbs; > 667 > 668 usb_make_path(usbdev, uirt->phys, sizeof(uirt->phys)); > 669 > 670 rc->device_name = "USB-UIRT"; > 671 rc->driver_name = KBUILD_MODNAME; > 672 rc->input_phys = uirt->phys; > 673 usb_to_input_id(usbdev, &rc->input_id); > 674 rc->dev.parent = &intf->dev; > 675 rc->priv = uirt; > 676 rc->tx_ir = uirt_tx; > 677 rc->s_tx_carrier = uirt_set_tx_carrier; > 678 rc->s_learning_mode = uirt_set_rx_wideband; > 679 rc->allowed_protocols = RC_PROTO_BIT_ALL_IR_DECODER; > 680 rc->map_name = RC_MAP_RC6_MCE; > 681 rc->rx_resolution = UNIT_US; > 682 rc->timeout = IR_TIMEOUT; > 683 > 684 uirt_set_tx_carrier(rc, 38000); > 685 > 686 err = rc_register_device(rc); > 687 if (err) > 688 goto kill_urbs; > 689 > 690 usb_set_intfdata(intf, uirt); > 691 > 692 return 0; > 693 > 694 kill_urbs: > 695 usb_kill_urb(uirt->urb_in); > 696 usb_kill_urb(uirt->urb_out); > 697 free_rcdev: > 698 usb_free_urb(uirt->urb_in); > 699 usb_free_urb(uirt->urb_out); > 700 rc_free_device(rc); > 701 free_uirt: > 702 kfree(uirt->in); > 703 kfree(uirt->out); > 704 kfree(uirt); > 705 return err; > 706 } > 707 > > --- > 0-DAY CI Kernel Test Service, Intel Corporation > https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org