Convert poll/select to operate more directly on linux.PollFD

Current, doPoll copies the user struct pollfd array into a
[]syscalls.PollFD, which contains internal kdefs.FD and
waiter.EventMask types. While these are currently binary-compatible with
the Linux versions, we generally discourage copying directly to internal
types (someone may inadvertantly change kdefs.FD to uint64).

Instead, copy directly to a []linux.PollFD, which will certainly be
binary compatible. Most of syscalls/polling.go is included directly into
syscalls/linux/sys_poll.go, as it can then operate directly on
linux.PollFD. The additional syscalls.PollFD type is providing little
value.

I've also added explicit conversion functions for waiter.EventMask,
which creates the possibility of a different binary format.

PiperOrigin-RevId: 244042947
Change-Id: I24e5b642002a32b3afb95a9dcb80d4acd1288abf

1 files changed, 1 insertions, 1 deletions

diff --git a/pkg/sentry/syscalls/linux/sys_epoll.go b/pkg/sentry/syscalls/linux/sys_epoll.go
index 62272efcd..200c46355 100644
--- a/pkg/sentry/syscalls/linux/sys_epoll.go
+++ b/pkg/sentry/syscalls/linux/sys_epoll.go
@@ -87,7 +87,7 @@ func EpollCtl(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.Sysc
 			flags |= epoll.EdgeTriggered
 		}
 
-		mask = waiter.EventMask(e.Events)
+		mask = waiter.EventMaskFromLinux(e.Events)
 		data[0] = e.Fd
 		data[1] = e.Pad
 	}