From: Willem de Bruijn <willemb@xxxxxxxxxx>
Subject: epoll: add syscall epoll_pwait2
Add syscall epoll_pwait2, an epoll_wait variant with nsec resolution that
replaces int timeout with struct timespec. It is equivalent otherwise.
int epoll_pwait2(int fd, struct epoll_event *events,
int maxevents,
const struct timespec *timeout,
const sigset_t *sigset);
The underlying hrtimer is already programmed with nsec resolution.
pselect and ppoll also set nsec resolution timeout with timespec.
The sigset_t in epoll_pwait has a compat variant. epoll_pwait2 needs
the same.
For timespec, only support this new interface on 2038 aware platforms
that define __kernel_timespec_t. So no CONFIG_COMPAT_32BIT_TIME.
Link: https://lkml.kernel.org/r/20201121144401.3727659-3-willemdebruijn.kernel@xxxxxxxxx
Signed-off-by: Willem de Bruijn <willemb@xxxxxxxxxx>
Cc: Al Viro <viro@xxxxxxxxxxxxxxxxxx>
Cc: Arnd Bergmann <arnd@xxxxxxxx>
Cc: Matthew Wilcox (Oracle) <willy@xxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
fs/eventpoll.c | 87 +++++++++++++++++++++++++++++++++++++++--------
1 file changed, 73 insertions(+), 14 deletions(-)
--- a/fs/eventpoll.c~epoll-add-syscall-epoll_pwait2
+++ a/fs/eventpoll.c
@@ -2237,11 +2237,10 @@ SYSCALL_DEFINE4(epoll_wait, int, epfd, s
* Implement the event wait interface for the eventpoll file. It is the kernel
* part of the user space epoll_pwait(2).
*/
-SYSCALL_DEFINE6(epoll_pwait, int, epfd, struct epoll_event __user *, events,
- int, maxevents, int, timeout, const sigset_t __user *, sigmask,
- size_t, sigsetsize)
+static int do_epoll_pwait(int epfd, struct epoll_event __user *events,
+ int maxevents, struct timespec64 *to,
+ const sigset_t __user *sigmask, size_t sigsetsize)
{
- struct timespec64 to;
int error;
/*
@@ -2252,22 +2251,48 @@ SYSCALL_DEFINE6(epoll_pwait, int, epfd,
if (error)
return error;
- error = do_epoll_wait(epfd, events, maxevents,
- ep_timeout_to_timespec(&to, timeout));
+ error = do_epoll_wait(epfd, events, maxevents, to);
restore_saved_sigmask_unless(error == -EINTR);
return error;
}
-#ifdef CONFIG_COMPAT
-COMPAT_SYSCALL_DEFINE6(epoll_pwait, int, epfd,
- struct epoll_event __user *, events,
- int, maxevents, int, timeout,
- const compat_sigset_t __user *, sigmask,
- compat_size_t, sigsetsize)
+SYSCALL_DEFINE6(epoll_pwait, int, epfd, struct epoll_event __user *, events,
+ int, maxevents, int, timeout, const sigset_t __user *, sigmask,
+ size_t, sigsetsize)
{
struct timespec64 to;
+
+ return do_epoll_pwait(epfd, events, maxevents,
+ ep_timeout_to_timespec(&to, timeout),
+ sigmask, sigsetsize);
+}
+
+SYSCALL_DEFINE6(epoll_pwait2, int, epfd, struct epoll_event __user *, events,
+ int, maxevents, const struct __kernel_timespec __user *, timeout,
+ const sigset_t __user *, sigmask, size_t, sigsetsize)
+{
+ struct timespec64 ts, *to = NULL;
+
+ if (timeout) {
+ if (get_timespec64(&ts, timeout))
+ return -EFAULT;
+ to = &ts;
+ if (poll_select_set_timeout(to, ts.tv_sec, ts.tv_nsec))
+ return -EINVAL;
+ }
+
+ return do_epoll_pwait(epfd, events, maxevents, to,
+ sigmask, sigsetsize);
+}
+
+#ifdef CONFIG_COMPAT
+static int do_compat_epoll_pwait(int epfd, struct epoll_event __user *events,
+ int maxevents, struct timespec64 *timeout,
+ const compat_sigset_t __user *sigmask,
+ compat_size_t sigsetsize)
+{
long err;
/*
@@ -2278,13 +2303,47 @@ COMPAT_SYSCALL_DEFINE6(epoll_pwait, int,
if (err)
return err;
- err = do_epoll_wait(epfd, events, maxevents,
- ep_timeout_to_timespec(&to, timeout));
+ err = do_epoll_wait(epfd, events, maxevents, timeout);
restore_saved_sigmask_unless(err == -EINTR);
return err;
}
+
+COMPAT_SYSCALL_DEFINE6(epoll_pwait, int, epfd,
+ struct epoll_event __user *, events,
+ int, maxevents, int, timeout,
+ const compat_sigset_t __user *, sigmask,
+ compat_size_t, sigsetsize)
+{
+ struct timespec64 to;
+
+ return do_compat_epoll_pwait(epfd, events, maxevents,
+ ep_timeout_to_timespec(&to, timeout),
+ sigmask, sigsetsize);
+}
+
+COMPAT_SYSCALL_DEFINE6(epoll_pwait2, int, epfd,
+ struct epoll_event __user *, events,
+ int, maxevents,
+ const struct __kernel_timespec __user *, timeout,
+ const compat_sigset_t __user *, sigmask,
+ compat_size_t, sigsetsize)
+{
+ struct timespec64 ts, *to = NULL;
+
+ if (timeout) {
+ if (get_timespec64(&ts, timeout))
+ return -EFAULT;
+ to = &ts;
+ if (poll_select_set_timeout(to, ts.tv_sec, ts.tv_nsec))
+ return -EINVAL;
+ }
+
+ return do_compat_epoll_pwait(epfd, events, maxevents, to,
+ sigmask, sigsetsize);
+}
+
#endif
static int __init eventpoll_init(void)
_
