Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
Merge tag 'vfs-6.15-rc1.eventpoll' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs
Pull vfs eventpoll updates from Christian Brauner:
"This contains a few preparatory changes to eventpoll to allow io_uring
to support epoll"
* tag 'vfs-6.15-rc1.eventpoll' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs:
eventpoll: add epoll_sendevents() helper
eventpoll: abstract out ep_try_send_events() helper
eventpoll: abstract out parameter sanity checking
+67
-24
+63
-24
fs/eventpoll.c
+63
-24
fs/eventpoll.c
···
1980
1980
return ret;
1981
1981
}
1982
1982
1983
+
static int ep_try_send_events(struct eventpoll *ep,
1984
+
struct epoll_event __user *events, int maxevents)
1985
+
{
1986
+
int res;
1987
+
1988
+
/*
1989
+
* Try to transfer events to user space. In case we get 0 events and
1990
+
* there's still timeout left over, we go trying again in search of
1991
+
* more luck.
1992
+
*/
1993
+
res = ep_send_events(ep, events, maxevents);
1994
+
if (res > 0)
1995
+
ep_suspend_napi_irqs(ep);
1996
+
return res;
1997
+
}
1998
+
1983
1999
/**
1984
2000
* ep_poll - Retrieves ready events, and delivers them to the caller-supplied
1985
2001
* event buffer.
···
2047
2031
2048
2032
while (1) {
2049
2033
if (eavail) {
2050
-
/*
2051
-
* Try to transfer events to user space. In case we get
2052
-
* 0 events and there's still timeout left over, we go
2053
-
* trying again in search of more luck.
2054
-
*/
2055
-
res = ep_send_events(ep, events, maxevents);
2056
-
if (res) {
2057
-
if (res > 0)
2058
-
ep_suspend_napi_irqs(ep);
2034
+
res = ep_try_send_events(ep, events, maxevents);
2035
+
if (res)
2059
2036
return res;
2060
-
}
2061
2037
}
2062
2038
2063
2039
if (timed_out)
···
2453
2445
return do_epoll_ctl(epfd, op, fd, &epds, false);
2454
2446
}
2455
2447
2448
+
static int ep_check_params(struct file *file, struct epoll_event __user *evs,
2449
+
int maxevents)
2450
+
{
2451
+
/* The maximum number of event must be greater than zero */
2452
+
if (maxevents <= 0 || maxevents > EP_MAX_EVENTS)
2453
+
return -EINVAL;
2454
+
2455
+
/* Verify that the area passed by the user is writeable */
2456
+
if (!access_ok(evs, maxevents * sizeof(struct epoll_event)))
2457
+
return -EFAULT;
2458
+
2459
+
/*
2460
+
* We have to check that the file structure underneath the fd
2461
+
* the user passed to us _is_ an eventpoll file.
2462
+
*/
2463
+
if (!is_file_epoll(file))
2464
+
return -EINVAL;
2465
+
2466
+
return 0;
2467
+
}
2468
+
2469
+
int epoll_sendevents(struct file *file, struct epoll_event __user *events,
2470
+
int maxevents)
2471
+
{
2472
+
struct eventpoll *ep;
2473
+
int ret;
2474
+
2475
+
ret = ep_check_params(file, events, maxevents);
2476
+
if (unlikely(ret))
2477
+
return ret;
2478
+
2479
+
ep = file->private_data;
2480
+
/*
2481
+
* Racy call, but that's ok - it should get retried based on
2482
+
* poll readiness anyway.
2483
+
*/
2484
+
if (ep_events_available(ep))
2485
+
return ep_try_send_events(ep, events, maxevents);
2486
+
return 0;
2487
+
}
2488
+
2456
2489
/*
2457
2490
* Implement the event wait interface for the eventpoll file. It is the kernel
2458
2491
* part of the user space epoll_wait(2).
···
2502
2453
int maxevents, struct timespec64 *to)
2503
2454
{
2504
2455
struct eventpoll *ep;
2505
-
2506
-
/* The maximum number of event must be greater than zero */
2507
-
if (maxevents <= 0 || maxevents > EP_MAX_EVENTS)
2508
-
return -EINVAL;
2509
-
2510
-
/* Verify that the area passed by the user is writeable */
2511
-
if (!access_ok(events, maxevents * sizeof(struct epoll_event)))
2512
-
return -EFAULT;
2456
+
int ret;
2513
2457
2514
2458
/* Get the "struct file *" for the eventpoll file */
2515
2459
CLASS(fd, f)(epfd);
2516
2460
if (fd_empty(f))
2517
2461
return -EBADF;
2518
2462
2519
-
/*
2520
-
* We have to check that the file structure underneath the fd
2521
-
* the user passed to us _is_ an eventpoll file.
2522
-
*/
2523
-
if (!is_file_epoll(fd_file(f)))
2524
-
return -EINVAL;
2463
+
ret = ep_check_params(fd_file(f), events, maxevents);
2464
+
if (unlikely(ret))
2465
+
return ret;
2525
2466
2526
2467
/*
2527
2468
* At this point it is safe to assume that the "private_data" contains
+4
include/linux/eventpoll.h
+4
include/linux/eventpoll.h
···
25
25
/* Used to release the epoll bits inside the "struct file" */
26
26
void eventpoll_release_file(struct file *file);
27
27
28
+
/* Copy ready events to userspace */
29
+
int epoll_sendevents(struct file *file, struct epoll_event __user *events,
30
+
int maxevents);
31
+
28
32
/*
29
33
* This is called from inside fs/file_table.c:__fput() to unlink files
30
34
* from the eventpoll interface. We need to have this facility to cleanup