* of fds to overcome nfds < 16390 descriptors limit (Tigran Aivazian).
*/
+#include <linux/kernel.h>
#include <linux/syscalls.h>
#include <linux/module.h>
#include <linux/slab.h>
-#include <linux/smp_lock.h>
#include <linux/poll.h>
#include <linux/personality.h> /* for STICKY_TIMEOUTS */
#include <linux/file.h>
+#include <linux/fdtable.h>
#include <linux/fs.h>
#include <linux/rcupdate.h>
#include <asm/uaccess.h>
-#define ROUND_UP(x,y) (((x)+(y)-1)/(y))
-#define DEFAULT_POLLMASK (POLLIN | POLLOUT | POLLRDNORM | POLLWRNORM)
-
-struct poll_table_entry {
- struct file * filp;
- wait_queue_t wait;
- wait_queue_head_t * wait_address;
-};
-
struct poll_table_page {
struct poll_table_page * next;
struct poll_table_entry * entry;
init_poll_funcptr(&pwq->pt, __pollwait);
pwq->error = 0;
pwq->table = NULL;
+ pwq->inline_index = 0;
}
EXPORT_SYMBOL(poll_initwait);
+static void free_poll_entry(struct poll_table_entry *entry)
+{
+ remove_wait_queue(entry->wait_address, &entry->wait);
+ fput(entry->filp);
+}
+
void poll_freewait(struct poll_wqueues *pwq)
{
struct poll_table_page * p = pwq->table;
+ int i;
+ for (i = 0; i < pwq->inline_index; i++)
+ free_poll_entry(pwq->inline_entries + i);
while (p) {
struct poll_table_entry * entry;
struct poll_table_page *old;
entry = p->entry;
do {
entry--;
- remove_wait_queue(entry->wait_address,&entry->wait);
- fput(entry->filp);
+ free_poll_entry(entry);
} while (entry > p->entries);
old = p;
p = p->next;
EXPORT_SYMBOL(poll_freewait);
-static void __pollwait(struct file *filp, wait_queue_head_t *wait_address,
- poll_table *_p)
+static struct poll_table_entry *poll_get_entry(poll_table *_p)
{
struct poll_wqueues *p = container_of(_p, struct poll_wqueues, pt);
struct poll_table_page *table = p->table;
+ if (p->inline_index < N_INLINE_POLL_ENTRIES)
+ return p->inline_entries + p->inline_index++;
+
if (!table || POLL_TABLE_FULL(table)) {
struct poll_table_page *new_table;
if (!new_table) {
p->error = -ENOMEM;
__set_current_state(TASK_RUNNING);
- return;
+ return NULL;
}
new_table->entry = new_table->entries;
new_table->next = table;
table = new_table;
}
- /* Add a new entry */
- {
- struct poll_table_entry * entry = table->entry;
- table->entry = entry+1;
- get_file(filp);
- entry->filp = filp;
- entry->wait_address = wait_address;
- init_waitqueue_entry(&entry->wait, current);
- add_wait_queue(wait_address,&entry->wait);
- }
+ return table->entry++;
+}
+
+/* Add a new entry */
+static void __pollwait(struct file *filp, wait_queue_head_t *wait_address,
+ poll_table *p)
+{
+ struct poll_table_entry *entry = poll_get_entry(p);
+ if (!entry)
+ return;
+ get_file(filp);
+ entry->filp = filp;
+ entry->wait_address = wait_address;
+ init_waitqueue_entry(&entry->wait, current);
+ add_wait_queue(wait_address, &entry->wait);
}
#define FDS_IN(fds, n) (fds->in + n)
return max;
}
-#define BIT(i) (1UL << ((i)&(__NFDBITS-1)))
-#define MEM(i,m) ((m)+(unsigned)(i)/__NFDBITS)
-#define ISSET(i,m) (((i)&*(m)) != 0)
-#define SET(i,m) (*(m) |= (i))
-
#define POLLIN_SET (POLLRDNORM | POLLRDBAND | POLLIN | POLLHUP | POLLERR)
#define POLLOUT_SET (POLLWRBAND | POLLWRNORM | POLLOUT | POLLERR)
#define POLLEX_SET (POLLPRI)
for (i = 0; i < n; ++rinp, ++routp, ++rexp) {
unsigned long in, out, ex, all_bits, bit = 1, mask, j;
unsigned long res_in = 0, res_out = 0, res_ex = 0;
- struct file_operations *f_op = NULL;
+ const struct file_operations *f_op = NULL;
struct file *file = NULL;
in = *inp++; out = *outp++; ex = *exp++;
}
for (j = 0; j < __NFDBITS; ++j, ++i, bit <<= 1) {
+ int fput_needed;
if (i >= n)
break;
if (!(bit & all_bits))
continue;
- file = fget(i);
+ file = fget_light(i, &fput_needed);
if (file) {
f_op = file->f_op;
mask = DEFAULT_POLLMASK;
if (f_op && f_op->poll)
mask = (*f_op->poll)(file, retval ? NULL : wait);
- fput(file);
+ fput_light(file, fput_needed);
if ((mask & POLLIN_SET) && (in & bit)) {
res_in |= bit;
retval++;
wait = NULL;
if (retval || !*timeout || signal_pending(current))
break;
- if(table.error) {
+ if (table.error) {
retval = table.error;
break;
}
return retval;
}
-static void *select_bits_alloc(int size)
-{
- return kmalloc(6 * size, GFP_KERNEL);
-}
-
-static void select_bits_free(void *bits, int size)
-{
- kfree(bits);
-}
-
/*
* We can actually return ERESTARTSYS instead of EINTR, but I'd
* like to be certain this leads to no problems. So I return
#define MAX_SELECT_SECONDS \
((unsigned long) (MAX_SCHEDULE_TIMEOUT / HZ)-1)
-static int core_sys_select(int n, fd_set __user *inp, fd_set __user *outp,
+int core_sys_select(int n, fd_set __user *inp, fd_set __user *outp,
fd_set __user *exp, s64 *timeout)
{
fd_set_bits fds;
- char *bits;
- int ret, size, max_fdset;
+ void *bits;
+ int ret, max_fds;
+ unsigned int size;
struct fdtable *fdt;
+ /* Allocate small arguments on the stack to save memory and be faster */
+ long stack_fds[SELECT_STACK_ALLOC/sizeof(long)];
ret = -EINVAL;
if (n < 0)
goto out_nofds;
- /* max_fdset can increase, so grab it once to avoid race */
+ /* max_fds can increase, so grab it once to avoid race */
rcu_read_lock();
fdt = files_fdtable(current->files);
- max_fdset = fdt->max_fdset;
+ max_fds = fdt->max_fds;
rcu_read_unlock();
- if (n > max_fdset)
- n = max_fdset;
+ if (n > max_fds)
+ n = max_fds;
/*
* We need 6 bitmaps (in/out/ex for both incoming and outgoing),
* since we used fdset we need to allocate memory in units of
* long-words.
*/
- ret = -ENOMEM;
size = FDS_BYTES(n);
- bits = select_bits_alloc(size);
- if (!bits)
- goto out_nofds;
- fds.in = (unsigned long *) bits;
- fds.out = (unsigned long *) (bits + size);
- fds.ex = (unsigned long *) (bits + 2*size);
- fds.res_in = (unsigned long *) (bits + 3*size);
- fds.res_out = (unsigned long *) (bits + 4*size);
- fds.res_ex = (unsigned long *) (bits + 5*size);
+ bits = stack_fds;
+ if (size > sizeof(stack_fds) / 6) {
+ /* Not enough space in on-stack array; must use kmalloc */
+ ret = -ENOMEM;
+ bits = kmalloc(6 * size, GFP_KERNEL);
+ if (!bits)
+ goto out_nofds;
+ }
+ fds.in = bits;
+ fds.out = bits + size;
+ fds.ex = bits + 2*size;
+ fds.res_in = bits + 3*size;
+ fds.res_out = bits + 4*size;
+ fds.res_ex = bits + 5*size;
if ((ret = get_fd_set(n, inp, fds.in)) ||
(ret = get_fd_set(n, outp, fds.out)) ||
ret = -EFAULT;
out:
- select_bits_free(bits, size);
+ if (bits != stack_fds)
+ kfree(bits);
out_nofds:
return ret;
}
if ((u64)tv.tv_sec >= (u64)MAX_INT64_SECONDS)
timeout = -1; /* infinite */
else {
- timeout = ROUND_UP(tv.tv_usec, USEC_PER_SEC/HZ);
+ timeout = DIV_ROUND_UP(tv.tv_usec, USEC_PER_SEC/HZ);
timeout += tv.tv_sec * HZ;
}
}
return ret;
}
-#ifdef TIF_RESTORE_SIGMASK
+#ifdef HAVE_SET_RESTORE_SIGMASK
asmlinkage long sys_pselect7(int n, fd_set __user *inp, fd_set __user *outp,
fd_set __user *exp, struct timespec __user *tsp,
const sigset_t __user *sigmask, size_t sigsetsize)
if ((u64)ts.tv_sec >= (u64)MAX_INT64_SECONDS)
timeout = -1; /* infinite */
else {
- timeout = ROUND_UP(ts.tv_nsec, NSEC_PER_SEC/HZ);
+ timeout = DIV_ROUND_UP(ts.tv_nsec, NSEC_PER_SEC/HZ);
timeout += ts.tv_sec * HZ;
}
}
if (sigmask) {
memcpy(¤t->saved_sigmask, &sigsaved,
sizeof(sigsaved));
- set_thread_flag(TIF_RESTORE_SIGMASK);
+ set_restore_sigmask();
}
} else if (sigmask)
sigprocmask(SIG_SETMASK, &sigsaved, NULL);
return sys_pselect7(n, inp, outp, exp, tsp, up, sigsetsize);
}
-#endif /* TIF_RESTORE_SIGMASK */
+#endif /* HAVE_SET_RESTORE_SIGMASK */
struct poll_list {
struct poll_list *next;
#define POLLFD_PER_PAGE ((PAGE_SIZE-sizeof(struct poll_list)) / sizeof(struct pollfd))
-static void do_pollfd(unsigned int num, struct pollfd * fdpage,
- poll_table ** pwait, int *count)
+/*
+ * Fish for pollable events on the pollfd->fd file descriptor. We're only
+ * interested in events matching the pollfd->events mask, and the result
+ * matching that mask is both recorded in pollfd->revents and returned. The
+ * pwait poll_table will be used by the fd-provided poll handler for waiting,
+ * if non-NULL.
+ */
+static inline unsigned int do_pollfd(struct pollfd *pollfd, poll_table *pwait)
{
- int i;
-
- for (i = 0; i < num; i++) {
- int fd;
- unsigned int mask;
- struct pollfd *fdp;
-
- mask = 0;
- fdp = fdpage+i;
- fd = fdp->fd;
- if (fd >= 0) {
- struct file * file = fget(fd);
- mask = POLLNVAL;
- if (file != NULL) {
- mask = DEFAULT_POLLMASK;
- if (file->f_op && file->f_op->poll)
- mask = file->f_op->poll(file, *pwait);
- mask &= fdp->events | POLLERR | POLLHUP;
- fput(file);
- }
- if (mask) {
- *pwait = NULL;
- (*count)++;
- }
+ unsigned int mask;
+ int fd;
+
+ mask = 0;
+ fd = pollfd->fd;
+ if (fd >= 0) {
+ int fput_needed;
+ struct file * file;
+
+ file = fget_light(fd, &fput_needed);
+ mask = POLLNVAL;
+ if (file != NULL) {
+ mask = DEFAULT_POLLMASK;
+ if (file->f_op && file->f_op->poll)
+ mask = file->f_op->poll(file, pwait);
+ /* Mask out unneeded events. */
+ mask &= pollfd->events | POLLERR | POLLHUP;
+ fput_light(file, fput_needed);
}
- fdp->revents = mask;
}
+ pollfd->revents = mask;
+
+ return mask;
}
static int do_poll(unsigned int nfds, struct poll_list *list,
/* Optimise the no-wait case */
if (!(*timeout))
pt = NULL;
-
+
for (;;) {
struct poll_list *walk;
long __timeout;
set_current_state(TASK_INTERRUPTIBLE);
- walk = list;
- while(walk != NULL) {
- do_pollfd( walk->len, walk->entries, &pt, &count);
- walk = walk->next;
+ for (walk = list; walk != NULL; walk = walk->next) {
+ struct pollfd * pfd, * pfd_end;
+
+ pfd = walk->entries;
+ pfd_end = pfd + walk->len;
+ for (; pfd != pfd_end; pfd++) {
+ /*
+ * Fish for events. If we found one, record it
+ * and kill the poll_table, so we don't
+ * needlessly register any other waiters after
+ * this. They'll get immediately deregistered
+ * when we break out and return.
+ */
+ if (do_pollfd(pfd, pt)) {
+ count++;
+ pt = NULL;
+ }
+ }
}
+ /*
+ * All waiters have already been registered, so don't provide
+ * a poll_table to them on the next loop iteration.
+ */
pt = NULL;
- if (count || !*timeout || signal_pending(current))
- break;
- count = wait->error;
- if (count)
+ if (!count) {
+ count = wait->error;
+ if (signal_pending(current))
+ count = -EINTR;
+ }
+ if (count || !*timeout)
break;
if (*timeout < 0) {
return count;
}
+#define N_STACK_PPS ((sizeof(stack_pps) - sizeof(struct poll_list)) / \
+ sizeof(struct pollfd))
+
int do_sys_poll(struct pollfd __user *ufds, unsigned int nfds, s64 *timeout)
{
struct poll_wqueues table;
- int fdcount, err;
- unsigned int i;
- struct poll_list *head;
- struct poll_list *walk;
- struct fdtable *fdt;
- int max_fdset;
-
- /* Do a sanity check on nfds ... */
- rcu_read_lock();
- fdt = files_fdtable(current->files);
- max_fdset = fdt->max_fdset;
- rcu_read_unlock();
- if (nfds > max_fdset && nfds > OPEN_MAX)
+ int err = -EFAULT, fdcount, len, size;
+ /* Allocate small arguments on the stack to save memory and be
+ faster - use long to make sure the buffer is aligned properly
+ on 64 bit archs to avoid unaligned access */
+ long stack_pps[POLL_STACK_ALLOC/sizeof(long)];
+ struct poll_list *const head = (struct poll_list *)stack_pps;
+ struct poll_list *walk = head;
+ unsigned long todo = nfds;
+
+ if (nfds > current->signal->rlim[RLIMIT_NOFILE].rlim_cur)
return -EINVAL;
- poll_initwait(&table);
+ len = min_t(unsigned int, nfds, N_STACK_PPS);
+ for (;;) {
+ walk->next = NULL;
+ walk->len = len;
+ if (!len)
+ break;
- head = NULL;
- walk = NULL;
- i = nfds;
- err = -ENOMEM;
- while(i!=0) {
- struct poll_list *pp;
- pp = kmalloc(sizeof(struct poll_list)+
- sizeof(struct pollfd)*
- (i>POLLFD_PER_PAGE?POLLFD_PER_PAGE:i),
- GFP_KERNEL);
- if(pp==NULL)
+ if (copy_from_user(walk->entries, ufds + nfds-todo,
+ sizeof(struct pollfd) * walk->len))
goto out_fds;
- pp->next=NULL;
- pp->len = (i>POLLFD_PER_PAGE?POLLFD_PER_PAGE:i);
- if (head == NULL)
- head = pp;
- else
- walk->next = pp;
- walk = pp;
- if (copy_from_user(pp->entries, ufds + nfds-i,
- sizeof(struct pollfd)*pp->len)) {
- err = -EFAULT;
+ todo -= walk->len;
+ if (!todo)
+ break;
+
+ len = min(todo, POLLFD_PER_PAGE);
+ size = sizeof(struct poll_list) + sizeof(struct pollfd) * len;
+ walk = walk->next = kmalloc(size, GFP_KERNEL);
+ if (!walk) {
+ err = -ENOMEM;
goto out_fds;
}
- i -= pp->len;
}
+ poll_initwait(&table);
fdcount = do_poll(nfds, head, &table, timeout);
+ poll_freewait(&table);
- /* OK, now copy the revents fields back to user space. */
- walk = head;
- err = -EFAULT;
- while(walk != NULL) {
+ for (walk = head; walk; walk = walk->next) {
struct pollfd *fds = walk->entries;
int j;
- for (j=0; j < walk->len; j++, ufds++) {
- if(__put_user(fds[j].revents, &ufds->revents))
+ for (j = 0; j < walk->len; j++, ufds++)
+ if (__put_user(fds[j].revents, &ufds->revents))
goto out_fds;
- }
- walk = walk->next;
}
+
err = fdcount;
- if (!fdcount && signal_pending(current))
- err = -EINTR;
out_fds:
- walk = head;
- while(walk!=NULL) {
- struct poll_list *pp = walk->next;
- kfree(walk);
- walk = pp;
+ walk = head->next;
+ while (walk) {
+ struct poll_list *pos = walk;
+ walk = walk->next;
+ kfree(pos);
}
- poll_freewait(&table);
+
return err;
}
+static long do_restart_poll(struct restart_block *restart_block)
+{
+ struct pollfd __user *ufds = (struct pollfd __user*)restart_block->arg0;
+ int nfds = restart_block->arg1;
+ s64 timeout = ((s64)restart_block->arg3<<32) | (s64)restart_block->arg2;
+ int ret;
+
+ ret = do_sys_poll(ufds, nfds, &timeout);
+ if (ret == -EINTR) {
+ restart_block->fn = do_restart_poll;
+ restart_block->arg2 = timeout & 0xFFFFFFFF;
+ restart_block->arg3 = (u64)timeout >> 32;
+ ret = -ERESTART_RESTARTBLOCK;
+ }
+ return ret;
+}
+
asmlinkage long sys_poll(struct pollfd __user *ufds, unsigned int nfds,
long timeout_msecs)
{
- s64 timeout_jiffies = 0;
+ s64 timeout_jiffies;
+ int ret;
- if (timeout_msecs) {
+ if (timeout_msecs > 0) {
#if HZ > 1000
/* We can only overflow if HZ > 1000 */
if (timeout_msecs / 1000 > (s64)0x7fffffffffffffffULL / (s64)HZ)
timeout_jiffies = -1;
else
#endif
- timeout_jiffies = msecs_to_jiffies(timeout_msecs);
+ timeout_jiffies = msecs_to_jiffies(timeout_msecs) + 1;
+ } else {
+ /* Infinite (< 0) or no (0) timeout */
+ timeout_jiffies = timeout_msecs;
}
- return do_sys_poll(ufds, nfds, &timeout_jiffies);
+ ret = do_sys_poll(ufds, nfds, &timeout_jiffies);
+ if (ret == -EINTR) {
+ struct restart_block *restart_block;
+ restart_block = ¤t_thread_info()->restart_block;
+ restart_block->fn = do_restart_poll;
+ restart_block->arg0 = (unsigned long)ufds;
+ restart_block->arg1 = nfds;
+ restart_block->arg2 = timeout_jiffies & 0xFFFFFFFF;
+ restart_block->arg3 = (u64)timeout_jiffies >> 32;
+ ret = -ERESTART_RESTARTBLOCK;
+ }
+ return ret;
}
-#ifdef TIF_RESTORE_SIGMASK
+#ifdef HAVE_SET_RESTORE_SIGMASK
asmlinkage long sys_ppoll(struct pollfd __user *ufds, unsigned int nfds,
struct timespec __user *tsp, const sigset_t __user *sigmask,
size_t sigsetsize)
if ((u64)ts.tv_sec >= (u64)MAX_INT64_SECONDS)
timeout = -1; /* infinite */
else {
- timeout = ROUND_UP(ts.tv_nsec, NSEC_PER_SEC/HZ);
+ timeout = DIV_ROUND_UP(ts.tv_nsec, NSEC_PER_SEC/HZ);
timeout += ts.tv_sec * HZ;
}
}
if (sigmask) {
memcpy(¤t->saved_sigmask, &sigsaved,
sizeof(sigsaved));
- set_thread_flag(TIF_RESTORE_SIGMASK);
+ set_restore_sigmask();
}
ret = -ERESTARTNOHAND;
} else if (sigmask)
return ret;
}
-#endif /* TIF_RESTORE_SIGMASK */
+#endif /* HAVE_SET_RESTORE_SIGMASK */