Re: [PATCH 2/7] poll: Add a poll_flags for poll_queue_proc()

From: kernel test robot
Date: Wed Sep 06 2023 - 13:31:57 EST

Hi Peter,

kernel test robot noticed the following build errors:

[auto build test ERROR on akpm-mm/mm-everything]

url: https://github.com/intel-lab-lkp/linux/commits/Peter-Xu/mm-userfaultfd-Make-uffd-read-wait-event-exclusive/20230906-054430
base: https://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm.git mm-everything
patch link: https://lore.kernel.org/r/20230905214235.320571-3-peterx%40redhat.com
patch subject: [PATCH 2/7] poll: Add a poll_flags for poll_queue_proc()
config: x86_64-buildonly-randconfig-005-20230906 (https://download.01.org/0day-ci/archive/20230907/202309070146.47KrWvAH-lkp@xxxxxxxxx/config)
compiler: gcc-12 (Debian 12.2.0-14) 12.2.0
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20230907/202309070146.47KrWvAH-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/202309070146.47KrWvAH-lkp@xxxxxxxxx/

All errors (new ones prefixed by >>):

drivers/xen/privcmd.c: In function 'privcmd_irqfd_assign':
>> drivers/xen/privcmd.c:965:40: error: passing argument 2 of 'init_poll_funcptr' from incompatible pointer type [-Werror=incompatible-pointer-types]
965 | init_poll_funcptr(&kirqfd->pt, irqfd_poll_func);
| ^~~~~~~~~~~~~~~
| |
| void (*)(struct file *, wait_queue_head_t *, poll_table *) {aka void (*)(struct file *, struct wait_queue_head *, struct poll_table_struct *)}
In file included from drivers/xen/privcmd.c:17:
include/linux/poll.h:76:70: note: expected 'poll_queue_proc' {aka 'void (*)(struct file *, struct wait_queue_head *, struct poll_table_struct *, unsigned int)'} but argument is of type 'void (*)(struct file *, wait_queue_head_t *, poll_table *)' {aka 'void (*)(struct file *, struct wait_queue_head *, struct poll_table_struct *)'}
76 | static inline void init_poll_funcptr(poll_table *pt, poll_queue_proc qproc)
| ~~~~~~~~~~~~~~~~^~~~~
cc1: some warnings being treated as errors


vim +/init_poll_funcptr +965 drivers/xen/privcmd.c

f8941e6c4c7129 Viresh Kumar 2023-08-22 924
f8941e6c4c7129 Viresh Kumar 2023-08-22 925 static int privcmd_irqfd_assign(struct privcmd_irqfd *irqfd)
f8941e6c4c7129 Viresh Kumar 2023-08-22 926 {
f8941e6c4c7129 Viresh Kumar 2023-08-22 927 struct privcmd_kernel_irqfd *kirqfd, *tmp;
f8941e6c4c7129 Viresh Kumar 2023-08-22 928 __poll_t events;
f8941e6c4c7129 Viresh Kumar 2023-08-22 929 struct fd f;
f8941e6c4c7129 Viresh Kumar 2023-08-22 930 void *dm_op;
f8941e6c4c7129 Viresh Kumar 2023-08-22 931 int ret;
f8941e6c4c7129 Viresh Kumar 2023-08-22 932
f8941e6c4c7129 Viresh Kumar 2023-08-22 933 kirqfd = kzalloc(sizeof(*kirqfd) + irqfd->size, GFP_KERNEL);
f8941e6c4c7129 Viresh Kumar 2023-08-22 934 if (!kirqfd)
f8941e6c4c7129 Viresh Kumar 2023-08-22 935 return -ENOMEM;
f8941e6c4c7129 Viresh Kumar 2023-08-22 936 dm_op = kirqfd + 1;
f8941e6c4c7129 Viresh Kumar 2023-08-22 937
f8941e6c4c7129 Viresh Kumar 2023-08-22 938 if (copy_from_user(dm_op, irqfd->dm_op, irqfd->size)) {
f8941e6c4c7129 Viresh Kumar 2023-08-22 939 ret = -EFAULT;
f8941e6c4c7129 Viresh Kumar 2023-08-22 940 goto error_kfree;
f8941e6c4c7129 Viresh Kumar 2023-08-22 941 }
f8941e6c4c7129 Viresh Kumar 2023-08-22 942
f8941e6c4c7129 Viresh Kumar 2023-08-22 943 kirqfd->xbufs.size = irqfd->size;
f8941e6c4c7129 Viresh Kumar 2023-08-22 944 set_xen_guest_handle(kirqfd->xbufs.h, dm_op);
f8941e6c4c7129 Viresh Kumar 2023-08-22 945 kirqfd->dom = irqfd->dom;
f8941e6c4c7129 Viresh Kumar 2023-08-22 946 INIT_WORK(&kirqfd->shutdown, irqfd_shutdown);
f8941e6c4c7129 Viresh Kumar 2023-08-22 947
f8941e6c4c7129 Viresh Kumar 2023-08-22 948 f = fdget(irqfd->fd);
f8941e6c4c7129 Viresh Kumar 2023-08-22 949 if (!f.file) {
f8941e6c4c7129 Viresh Kumar 2023-08-22 950 ret = -EBADF;
f8941e6c4c7129 Viresh Kumar 2023-08-22 951 goto error_kfree;
f8941e6c4c7129 Viresh Kumar 2023-08-22 952 }
f8941e6c4c7129 Viresh Kumar 2023-08-22 953
f8941e6c4c7129 Viresh Kumar 2023-08-22 954 kirqfd->eventfd = eventfd_ctx_fileget(f.file);
f8941e6c4c7129 Viresh Kumar 2023-08-22 955 if (IS_ERR(kirqfd->eventfd)) {
f8941e6c4c7129 Viresh Kumar 2023-08-22 956 ret = PTR_ERR(kirqfd->eventfd);
f8941e6c4c7129 Viresh Kumar 2023-08-22 957 goto error_fd_put;
f8941e6c4c7129 Viresh Kumar 2023-08-22 958 }
f8941e6c4c7129 Viresh Kumar 2023-08-22 959
f8941e6c4c7129 Viresh Kumar 2023-08-22 960 /*
f8941e6c4c7129 Viresh Kumar 2023-08-22 961 * Install our own custom wake-up handling so we are notified via a
f8941e6c4c7129 Viresh Kumar 2023-08-22 962 * callback whenever someone signals the underlying eventfd.
f8941e6c4c7129 Viresh Kumar 2023-08-22 963 */
f8941e6c4c7129 Viresh Kumar 2023-08-22 964 init_waitqueue_func_entry(&kirqfd->wait, irqfd_wakeup);
f8941e6c4c7129 Viresh Kumar 2023-08-22 @965 init_poll_funcptr(&kirqfd->pt, irqfd_poll_func);
f8941e6c4c7129 Viresh Kumar 2023-08-22 966
f8941e6c4c7129 Viresh Kumar 2023-08-22 967 mutex_lock(&irqfds_lock);
f8941e6c4c7129 Viresh Kumar 2023-08-22 968
f8941e6c4c7129 Viresh Kumar 2023-08-22 969 list_for_each_entry(tmp, &irqfds_list, list) {
f8941e6c4c7129 Viresh Kumar 2023-08-22 970 if (kirqfd->eventfd == tmp->eventfd) {
f8941e6c4c7129 Viresh Kumar 2023-08-22 971 ret = -EBUSY;
f8941e6c4c7129 Viresh Kumar 2023-08-22 972 mutex_unlock(&irqfds_lock);
f8941e6c4c7129 Viresh Kumar 2023-08-22 973 goto error_eventfd;
f8941e6c4c7129 Viresh Kumar 2023-08-22 974 }
f8941e6c4c7129 Viresh Kumar 2023-08-22 975 }
f8941e6c4c7129 Viresh Kumar 2023-08-22 976
f8941e6c4c7129 Viresh Kumar 2023-08-22 977 list_add_tail(&kirqfd->list, &irqfds_list);
f8941e6c4c7129 Viresh Kumar 2023-08-22 978 mutex_unlock(&irqfds_lock);
f8941e6c4c7129 Viresh Kumar 2023-08-22 979
f8941e6c4c7129 Viresh Kumar 2023-08-22 980 /*
f8941e6c4c7129 Viresh Kumar 2023-08-22 981 * Check if there was an event already pending on the eventfd before we
f8941e6c4c7129 Viresh Kumar 2023-08-22 982 * registered, and trigger it as if we didn't miss it.
f8941e6c4c7129 Viresh Kumar 2023-08-22 983 */
f8941e6c4c7129 Viresh Kumar 2023-08-22 984 events = vfs_poll(f.file, &kirqfd->pt);
f8941e6c4c7129 Viresh Kumar 2023-08-22 985 if (events & EPOLLIN)
f8941e6c4c7129 Viresh Kumar 2023-08-22 986 irqfd_inject(kirqfd);
f8941e6c4c7129 Viresh Kumar 2023-08-22 987
f8941e6c4c7129 Viresh Kumar 2023-08-22 988 /*
f8941e6c4c7129 Viresh Kumar 2023-08-22 989 * Do not drop the file until the kirqfd is fully initialized, otherwise
f8941e6c4c7129 Viresh Kumar 2023-08-22 990 * we might race against the EPOLLHUP.
f8941e6c4c7129 Viresh Kumar 2023-08-22 991 */
f8941e6c4c7129 Viresh Kumar 2023-08-22 992 fdput(f);
f8941e6c4c7129 Viresh Kumar 2023-08-22 993 return 0;
f8941e6c4c7129 Viresh Kumar 2023-08-22 994
f8941e6c4c7129 Viresh Kumar 2023-08-22 995 error_eventfd:
f8941e6c4c7129 Viresh Kumar 2023-08-22 996 eventfd_ctx_put(kirqfd->eventfd);
f8941e6c4c7129 Viresh Kumar 2023-08-22 997
f8941e6c4c7129 Viresh Kumar 2023-08-22 998 error_fd_put:
f8941e6c4c7129 Viresh Kumar 2023-08-22 999 fdput(f);
f8941e6c4c7129 Viresh Kumar 2023-08-22 1000
f8941e6c4c7129 Viresh Kumar 2023-08-22 1001 error_kfree:
f8941e6c4c7129 Viresh Kumar 2023-08-22 1002 kfree(kirqfd);
f8941e6c4c7129 Viresh Kumar 2023-08-22 1003 return ret;
f8941e6c4c7129 Viresh Kumar 2023-08-22 1004 }
f8941e6c4c7129 Viresh Kumar 2023-08-22 1005

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