Re: [PATCH V2 2/2] xen: privcmd: Add support for irqfd

[kernel test robot <lkp@xxxxxxxxx>]

Hi Viresh,

kernel test robot noticed the following build errors:

[auto build test ERROR on xen-tip/linux-next]
[also build test ERROR on linus/master v6.5-rc2 next-20230721]
[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#_base_tree_information]

url:    
https://github.com/intel-lab-lkp/linux/commits/Viresh-Kumar/xen-privcmd-Add-support-for-irqfd/20230720-173905
base:   https://git.kernel.org/pub/scm/linux/kernel/git/xen/tip.git linux-next
patch link:    
https://lore.kernel.org/r/a25d5f01fe9b4624aa12cab77abd001044ea02d5.1689845210.git.viresh.kumar%40linaro.org
patch subject: [PATCH V2 2/2] xen: privcmd: Add support for irqfd
config: x86_64-randconfig-r091-20230723 
(https://download.01.org/0day-ci/archive/20230723/202307231237.JHGxqmdg-lkp@xxxxxxxxx/config)
compiler: gcc-12 (Debian 12.2.0-14) 12.2.0
reproduce: 
(https://download.01.org/0day-ci/archive/20230723/202307231237.JHGxqmdg-lkp@xxxxxxxxx/reproduce)

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/202307231237.JHGxqmdg-lkp@xxxxxxxxx/

All error/warnings (new ones prefixed by >>):

   drivers/xen/privcmd.c: In function 'privcmd_irqfd_assign':
>> drivers/xen/privcmd.c:961:19: error: implicit declaration of function 
>> 'eventfd_ctx_fileget'; did you mean 'eventfd_ctx_fdget'? 
>> [-Werror=implicit-function-declaration]
     961 |         eventfd = eventfd_ctx_fileget(f.file);
         |                   ^~~~~~~~~~~~~~~~~~~
         |                   eventfd_ctx_fdget
>> drivers/xen/privcmd.c:961:17: warning: assignment to 'struct eventfd_ctx *' 
>> from 'int' makes pointer from integer without a cast [-Wint-conversion]
     961 |         eventfd = eventfd_ctx_fileget(f.file);
         |                 ^
   cc1: some warnings being treated as errors


vim +961 drivers/xen/privcmd.c

   936  
   937  static int privcmd_irqfd_assign(struct privcmd_irqfd *irqfd)
   938  {
   939          struct privcmd_kernel_irqfd *kirqfd, *tmp;
   940          struct eventfd_ctx *eventfd;
   941          __poll_t events;
   942          struct fd f;
   943          int ret;
   944  
   945          kirqfd = kzalloc(sizeof(*kirqfd), GFP_KERNEL);
   946          if (!kirqfd)
   947                  return -ENOMEM;
   948  
   949          kirqfd->irq = irqfd->irq;
   950          kirqfd->dom = irqfd->dom;
   951          kirqfd->level = irqfd->level;
   952          INIT_LIST_HEAD(&kirqfd->list);
   953          INIT_WORK(&kirqfd->shutdown, irqfd_shutdown);
   954  
   955          f = fdget(irqfd->fd);
   956          if (!f.file) {
   957                  ret = -EBADF;
   958                  goto error_kfree;
   959          }
   960  
 > 961          eventfd = eventfd_ctx_fileget(f.file);
   962          if (IS_ERR(eventfd)) {
   963                  ret = PTR_ERR(eventfd);
   964                  goto error_fd_put;
   965          }
   966  
   967          kirqfd->eventfd = eventfd;
   968  
   969          /*
   970           * Install our own custom wake-up handling so we are notified 
via a
   971           * callback whenever someone signals the underlying eventfd.
   972           */
   973          init_waitqueue_func_entry(&kirqfd->wait, irqfd_wakeup);
   974          init_poll_funcptr(&kirqfd->pt, irqfd_poll_func);
   975  
   976          mutex_lock(&irqfds_lock);
   977  
   978          list_for_each_entry(tmp, &irqfds_list, list) {
   979                  if (kirqfd->eventfd == tmp->eventfd) {
   980                          ret = -EBUSY;
   981                          mutex_unlock(&irqfds_lock);
   982                          goto error_eventfd;
   983                  }
   984          }
   985  
   986          list_add_tail(&kirqfd->list, &irqfds_list);
   987          mutex_unlock(&irqfds_lock);
   988  
   989          /*
   990           * Check if there was an event already pending on the eventfd 
before we
   991           * registered, and trigger it as if we didn't miss it.
   992           */
   993          events = vfs_poll(f.file, &kirqfd->pt);
   994          if (events & EPOLLIN)
   995                  irqfd_inject(kirqfd);
   996  
   997          /*
   998           * Do not drop the file until the kirqfd is fully initialized, 
otherwise
   999           * we might race against the EPOLLHUP.
  1000           */
  1001          fdput(f);
  1002          return 0;
  1003  
  1004  error_eventfd:
  1005          eventfd_ctx_put(eventfd);
  1006  
  1007  error_fd_put:
  1008          fdput(f);
  1009  
  1010  error_kfree:
  1011          kfree(kirqfd);
  1012          return ret;
  1013  }
  1014  

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