v4.19.13 snapshot.
diff --git a/include/linux/poll.h b/include/linux/poll.h
new file mode 100644
index 0000000..7e0fdcf
--- /dev/null
+++ b/include/linux/poll.h
@@ -0,0 +1,145 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _LINUX_POLL_H
+#define _LINUX_POLL_H
+
+
+#include <linux/compiler.h>
+#include <linux/ktime.h>
+#include <linux/wait.h>
+#include <linux/string.h>
+#include <linux/fs.h>
+#include <linux/sysctl.h>
+#include <linux/uaccess.h>
+#include <uapi/linux/poll.h>
+#include <uapi/linux/eventpoll.h>
+
+extern struct ctl_table epoll_table[]; /* for sysctl */
+/* ~832 bytes of stack space used max in sys_select/sys_poll before allocating
+ additional memory. */
+#define MAX_STACK_ALLOC 832
+#define FRONTEND_STACK_ALLOC 256
+#define SELECT_STACK_ALLOC FRONTEND_STACK_ALLOC
+#define POLL_STACK_ALLOC FRONTEND_STACK_ALLOC
+#define WQUEUES_STACK_ALLOC (MAX_STACK_ALLOC - FRONTEND_STACK_ALLOC)
+#define N_INLINE_POLL_ENTRIES (WQUEUES_STACK_ALLOC / sizeof(struct poll_table_entry))
+
+#define DEFAULT_POLLMASK (EPOLLIN | EPOLLOUT | EPOLLRDNORM | EPOLLWRNORM)
+
+struct poll_table_struct;
+
+/*
+ * structures and helpers for f_op->poll implementations
+ */
+typedef void (*poll_queue_proc)(struct file *, wait_queue_head_t *, struct poll_table_struct *);
+
+/*
+ * Do not touch the structure directly, use the access functions
+ * poll_does_not_wait() and poll_requested_events() instead.
+ */
+typedef struct poll_table_struct {
+ poll_queue_proc _qproc;
+ __poll_t _key;
+} poll_table;
+
+static inline void poll_wait(struct file * filp, wait_queue_head_t * wait_address, poll_table *p)
+{
+ if (p && p->_qproc && wait_address)
+ p->_qproc(filp, wait_address, p);
+}
+
+/*
+ * Return true if it is guaranteed that poll will not wait. This is the case
+ * if the poll() of another file descriptor in the set got an event, so there
+ * is no need for waiting.
+ */
+static inline bool poll_does_not_wait(const poll_table *p)
+{
+ return p == NULL || p->_qproc == NULL;
+}
+
+/*
+ * Return the set of events that the application wants to poll for.
+ * This is useful for drivers that need to know whether a DMA transfer has
+ * to be started implicitly on poll(). You typically only want to do that
+ * if the application is actually polling for POLLIN and/or POLLOUT.
+ */
+static inline __poll_t poll_requested_events(const poll_table *p)
+{
+ return p ? p->_key : ~(__poll_t)0;
+}
+
+static inline void init_poll_funcptr(poll_table *pt, poll_queue_proc qproc)
+{
+ pt->_qproc = qproc;
+ pt->_key = ~(__poll_t)0; /* all events enabled */
+}
+
+static inline bool file_can_poll(struct file *file)
+{
+ return file->f_op->poll;
+}
+
+static inline __poll_t vfs_poll(struct file *file, struct poll_table_struct *pt)
+{
+ if (unlikely(!file->f_op->poll))
+ return DEFAULT_POLLMASK;
+ return file->f_op->poll(file, pt);
+}
+
+struct poll_table_entry {
+ struct file *filp;
+ __poll_t key;
+ wait_queue_entry_t wait;
+ wait_queue_head_t *wait_address;
+};
+
+/*
+ * Structures and helpers for select/poll syscall
+ */
+struct poll_wqueues {
+ poll_table pt;
+ struct poll_table_page *table;
+ struct task_struct *polling_task;
+ int triggered;
+ int error;
+ int inline_index;
+ struct poll_table_entry inline_entries[N_INLINE_POLL_ENTRIES];
+};
+
+extern void poll_initwait(struct poll_wqueues *pwq);
+extern void poll_freewait(struct poll_wqueues *pwq);
+extern u64 select_estimate_accuracy(struct timespec64 *tv);
+
+#define MAX_INT64_SECONDS (((s64)(~((u64)0)>>1)/HZ)-1)
+
+extern int core_sys_select(int n, fd_set __user *inp, fd_set __user *outp,
+ fd_set __user *exp, struct timespec64 *end_time);
+
+extern int poll_select_set_timeout(struct timespec64 *to, time64_t sec,
+ long nsec);
+
+#define __MAP(v, from, to) \
+ (from < to ? (v & from) * (to/from) : (v & from) / (from/to))
+
+static inline __u16 mangle_poll(__poll_t val)
+{
+ __u16 v = (__force __u16)val;
+#define M(X) __MAP(v, (__force __u16)EPOLL##X, POLL##X)
+ return M(IN) | M(OUT) | M(PRI) | M(ERR) | M(NVAL) |
+ M(RDNORM) | M(RDBAND) | M(WRNORM) | M(WRBAND) |
+ M(HUP) | M(RDHUP) | M(MSG);
+#undef M
+}
+
+static inline __poll_t demangle_poll(u16 val)
+{
+#define M(X) (__force __poll_t)__MAP(val, POLL##X, (__force __u16)EPOLL##X)
+ return M(IN) | M(OUT) | M(PRI) | M(ERR) | M(NVAL) |
+ M(RDNORM) | M(RDBAND) | M(WRNORM) | M(WRBAND) |
+ M(HUP) | M(RDHUP) | M(MSG);
+#undef M
+}
+#undef __MAP
+
+
+#endif /* _LINUX_POLL_H */