Re: [PATCH 1/1] eventfd new tag EFD_VPOLL: generate epoll events

[kbuild test robot <lkp@xxxxxxxxx>]

Hi Renzo,

Thank you for the patch! Yet something to improve:

[auto build test ERROR on linus/master]
[also build test ERROR on v5.2-rc1 next-20190524]
[if your patch is applied to the wrong git tree, please drop us a note to help improve the system]

url:    https://github.com/0day-ci/linux/commits/Renzo-Davoli/eventfd-new-tag-EFD_VPOLL-generate-epoll-events/20190527-023620
config: i386-randconfig-x011-201921 (attached as .config)
compiler: gcc-7 (Debian 7.3.0-1) 7.3.0
reproduce:
        # save the attached .config to linux build tree
        make ARCH=i386 

If you fix the issue, kindly add following tag
Reported-by: kbuild test robot <lkp@xxxxxxxxx>

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

   In file included from fs/eventfd.c:23:0:
   fs/eventfd.c: In function 'eventfd_vpoll_write':
>> include/linux/eventfd.h:31:34: warning: left shift count >= width of type [-Wshift-count-overflow]
    #define EFD_VPOLL_ADDEVENTS (1UL << 32)
                                     ^
>> fs/eventfd.c:360:7: note: in expansion of macro 'EFD_VPOLL_ADDEVENTS'
     case EFD_VPOLL_ADDEVENTS:
          ^~~~~~~~~~~~~~~~~~~
   include/linux/eventfd.h:32:34: warning: left shift count >= width of type [-Wshift-count-overflow]
    #define EFD_VPOLL_DELEVENTS (2UL << 32)
                                     ^
>> fs/eventfd.c:363:7: note: in expansion of macro 'EFD_VPOLL_DELEVENTS'
     case EFD_VPOLL_DELEVENTS:
          ^~~~~~~~~~~~~~~~~~~
>> fs/eventfd.c:363:2: error: duplicate case value
     case EFD_VPOLL_DELEVENTS:
     ^~~~
   fs/eventfd.c:360:2: note: previously used here
     case EFD_VPOLL_ADDEVENTS:
     ^~~~
   In file included from fs/eventfd.c:23:0:
   include/linux/eventfd.h:33:34: warning: left shift count >= width of type [-Wshift-count-overflow]
    #define EFD_VPOLL_MODEVENTS (3UL << 32)
                                     ^
>> fs/eventfd.c:366:7: note: in expansion of macro 'EFD_VPOLL_MODEVENTS'
     case EFD_VPOLL_MODEVENTS:
          ^~~~~~~~~~~~~~~~~~~
   fs/eventfd.c:366:2: error: duplicate case value
     case EFD_VPOLL_MODEVENTS:
     ^~~~
   fs/eventfd.c:360:2: note: previously used here
     case EFD_VPOLL_ADDEVENTS:
     ^~~~

vim +363 fs/eventfd.c

   342	
   343	static ssize_t eventfd_vpoll_write(struct file *file, const char __user *buf,
   344			size_t count, loff_t *ppos)
   345	{
   346		struct eventfd_ctx *ctx = file->private_data;
   347		ssize_t res;
   348		__u64 ucnt;
   349		__u32 events;
   350	
   351		if (count < sizeof(ucnt))
   352			return -EINVAL;
   353		if (copy_from_user(&ucnt, buf, sizeof(ucnt)))
   354			return -EFAULT;
   355		spin_lock_irq(&ctx->wqh.lock);
   356	
   357		events = ucnt & EPOLLALLMASK;
   358		res = sizeof(ucnt);
   359		switch (ucnt & ~((__u64)EPOLLALLMASK)) {
 > 360		case EFD_VPOLL_ADDEVENTS:
   361			ctx->count |= events;
   362			break;
 > 363		case EFD_VPOLL_DELEVENTS:
   364			ctx->count &= ~(events);
   365			break;
 > 366		case EFD_VPOLL_MODEVENTS:
   367			ctx->count = (ctx->count & ~EPOLLALLMASK) | events;
   368			break;
   369		default:
   370			res = -EINVAL;
   371		}
   372	
   373		/* wake up waiting threads */
   374		if (res >= 0 && waitqueue_active(&ctx->wqh))
   375			wake_up_locked_poll(&ctx->wqh, res);
   376	
   377		spin_unlock_irq(&ctx->wqh.lock);
   378	
   379		return res;
   380	

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0-DAY kernel test infrastructure                Open Source Technology Center
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