* of fds to overcome nfds < 16390 descriptors limit (Tigran Aivazian).
*/
+#include <linux/kernel.h>
+#include <linux/sched.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 <linux/hrtimer.h>
#include <asm/uaccess.h>
-#define ROUND_UP(x,y) (((x)+(y)-1)/(y))
-#define DEFAULT_POLLMASK (POLLIN | POLLOUT | POLLRDNORM | POLLWRNORM)
+
+/*
+ * Estimate expected accuracy in ns from a timeval.
+ *
+ * After quite a bit of churning around, we've settled on
+ * a simple thing of taking 0.1% of the timeout as the
+ * slack, with a cap of 100 msec.
+ * "nice" tasks get a 0.5% slack instead.
+ *
+ * Consider this comment an open invitation to come up with even
+ * better solutions..
+ */
+
+#define MAX_SLACK (100 * NSEC_PER_MSEC)
+
+static long __estimate_accuracy(struct timespec *tv)
+{
+ long slack;
+ int divfactor = 1000;
+
+ if (tv->tv_sec < 0)
+ return 0;
+
+ if (task_nice(current) > 0)
+ divfactor = divfactor / 5;
+
+ if (tv->tv_sec > MAX_SLACK / (NSEC_PER_SEC/divfactor))
+ return MAX_SLACK;
+
+ slack = tv->tv_nsec / divfactor;
+ slack += tv->tv_sec * (NSEC_PER_SEC/divfactor);
+
+ if (slack > MAX_SLACK)
+ return MAX_SLACK;
+
+ return slack;
+}
+
+long select_estimate_accuracy(struct timespec *tv)
+{
+ unsigned long ret;
+ struct timespec now;
+
+ /*
+ * Realtime tasks get a slack of 0 for obvious reasons.
+ */
+
+ if (rt_task(current))
+ return 0;
+
+ ktime_get_ts(&now);
+ now = timespec_sub(*tv, now);
+ ret = __estimate_accuracy(&now);
+ if (ret < current->timer_slack_ns)
+ return current->timer_slack_ns;
+ return ret;
+}
+
+
struct poll_table_page {
struct poll_table_page * next;
void poll_initwait(struct poll_wqueues *pwq)
{
init_poll_funcptr(&pwq->pt, __pollwait);
+ pwq->polling_task = current;
+ pwq->triggered = 0;
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);
+ remove_wait_queue(entry->wait_address, &entry->wait);
fput(entry->filp);
}
free_page((unsigned long) old);
}
}
-
EXPORT_SYMBOL(poll_freewait);
-static struct poll_table_entry *poll_get_entry(poll_table *_p)
+static struct poll_table_entry *poll_get_entry(struct poll_wqueues *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)
new_table = (struct poll_table_page *) __get_free_page(GFP_KERNEL);
if (!new_table) {
p->error = -ENOMEM;
- __set_current_state(TASK_RUNNING);
return NULL;
}
new_table->entry = new_table->entries;
return table->entry++;
}
+static int __pollwake(wait_queue_t *wait, unsigned mode, int sync, void *key)
+{
+ struct poll_wqueues *pwq = wait->private;
+ DECLARE_WAITQUEUE(dummy_wait, pwq->polling_task);
+
+ /*
+ * Although this function is called under waitqueue lock, LOCK
+ * doesn't imply write barrier and the users expect write
+ * barrier semantics on wakeup functions. The following
+ * smp_wmb() is equivalent to smp_wmb() in try_to_wake_up()
+ * and is paired with set_mb() in poll_schedule_timeout.
+ */
+ smp_wmb();
+ pwq->triggered = 1;
+
+ /*
+ * Perform the default wake up operation using a dummy
+ * waitqueue.
+ *
+ * TODO: This is hacky but there currently is no interface to
+ * pass in @sync. @sync is scheduled to be removed and once
+ * that happens, wake_up_process() can be used directly.
+ */
+ return default_wake_function(&dummy_wait, mode, sync, key);
+}
+
+static int pollwake(wait_queue_t *wait, unsigned mode, int sync, void *key)
+{
+ struct poll_table_entry *entry;
+
+ entry = container_of(wait, struct poll_table_entry, wait);
+ if (key && !((unsigned long)key & entry->key))
+ return 0;
+ return __pollwake(wait, mode, sync, key);
+}
+
/* 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);
+ struct poll_wqueues *pwq = container_of(p, struct poll_wqueues, pt);
+ struct poll_table_entry *entry = poll_get_entry(pwq);
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);
+ entry->key = p->key;
+ init_waitqueue_func_entry(&entry->wait, pollwake);
+ entry->wait.private = pwq;
+ add_wait_queue(wait_address, &entry->wait);
+}
+
+int poll_schedule_timeout(struct poll_wqueues *pwq, int state,
+ ktime_t *expires, unsigned long slack)
+{
+ int rc = -EINTR;
+
+ set_current_state(state);
+ if (!pwq->triggered)
+ rc = schedule_hrtimeout_range(expires, slack, HRTIMER_MODE_ABS);
+ __set_current_state(TASK_RUNNING);
+
+ /*
+ * Prepare for the next iteration.
+ *
+ * The following set_mb() serves two purposes. First, it's
+ * the counterpart rmb of the wmb in pollwake() such that data
+ * written before wake up is always visible after wake up.
+ * Second, the full barrier guarantees that triggered clearing
+ * doesn't pass event check of the next iteration. Note that
+ * this problem doesn't exist for the first iteration as
+ * add_wait_queue() has full barrier semantics.
+ */
+ set_mb(pwq->triggered, 0);
+
+ return rc;
+}
+EXPORT_SYMBOL(poll_schedule_timeout);
+
+/**
+ * poll_select_set_timeout - helper function to setup the timeout value
+ * @to: pointer to timespec variable for the final timeout
+ * @sec: seconds (from user space)
+ * @nsec: nanoseconds (from user space)
+ *
+ * Note, we do not use a timespec for the user space value here, That
+ * way we can use the function for timeval and compat interfaces as well.
+ *
+ * Returns -EINVAL if sec/nsec are not normalized. Otherwise 0.
+ */
+int poll_select_set_timeout(struct timespec *to, long sec, long nsec)
+{
+ struct timespec ts = {.tv_sec = sec, .tv_nsec = nsec};
+
+ if (!timespec_valid(&ts))
+ return -EINVAL;
+
+ /* Optimize for the zero timeout value here */
+ if (!sec && !nsec) {
+ to->tv_sec = to->tv_nsec = 0;
+ } else {
+ ktime_get_ts(to);
+ *to = timespec_add_safe(*to, ts);
+ }
+ return 0;
+}
+
+static int poll_select_copy_remaining(struct timespec *end_time, void __user *p,
+ int timeval, int ret)
+{
+ struct timespec rts;
+ struct timeval rtv;
+
+ if (!p)
+ return ret;
+
+ if (current->personality & STICKY_TIMEOUTS)
+ goto sticky;
+
+ /* No update for zero timeout */
+ if (!end_time->tv_sec && !end_time->tv_nsec)
+ return ret;
+
+ ktime_get_ts(&rts);
+ rts = timespec_sub(*end_time, rts);
+ if (rts.tv_sec < 0)
+ rts.tv_sec = rts.tv_nsec = 0;
+
+ if (timeval) {
+ if (sizeof(rtv) > sizeof(rtv.tv_sec) + sizeof(rtv.tv_usec))
+ memset(&rtv, 0, sizeof(rtv));
+ rtv.tv_sec = rts.tv_sec;
+ rtv.tv_usec = rts.tv_nsec / NSEC_PER_USEC;
+
+ if (!copy_to_user(p, &rtv, sizeof(rtv)))
+ return ret;
+
+ } else if (!copy_to_user(p, &rts, sizeof(rts)))
+ return ret;
+
+ /*
+ * If an application puts its timeval in read-only memory, we
+ * don't want the Linux-specific update to the timeval to
+ * cause a fault after the select has completed
+ * successfully. However, because we're not updating the
+ * timeval, we can't restart the system call.
+ */
+
+sticky:
+ if (ret == -ERESTARTNOHAND)
+ ret = -EINTR;
+ return ret;
}
#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)
-int do_select(int n, fd_set_bits *fds, s64 *timeout)
+static inline void wait_key_set(poll_table *wait, unsigned long in,
+ unsigned long out, unsigned long bit)
{
+ if (wait) {
+ wait->key = POLLEX_SET;
+ if (in & bit)
+ wait->key |= POLLIN_SET;
+ if (out & bit)
+ wait->key |= POLLOUT_SET;
+ }
+}
+
+int do_select(int n, fd_set_bits *fds, struct timespec *end_time)
+{
+ ktime_t expire, *to = NULL;
struct poll_wqueues table;
poll_table *wait;
- int retval, i;
+ int retval, i, timed_out = 0;
+ unsigned long slack = 0;
rcu_read_lock();
retval = max_select_fd(n, fds);
poll_initwait(&table);
wait = &table.pt;
- if (!*timeout)
+ if (end_time && !end_time->tv_sec && !end_time->tv_nsec) {
wait = NULL;
+ timed_out = 1;
+ }
+
+ if (end_time && !timed_out)
+ slack = select_estimate_accuracy(end_time);
+
retval = 0;
for (;;) {
unsigned long *rinp, *routp, *rexp, *inp, *outp, *exp;
- long __timeout;
-
- set_current_state(TASK_INTERRUPTIBLE);
inp = fds->in; outp = fds->out; exp = fds->ex;
rinp = fds->res_in; routp = fds->res_out; rexp = fds->res_ex;
if (file) {
f_op = file->f_op;
mask = DEFAULT_POLLMASK;
- if (f_op && f_op->poll)
- mask = (*f_op->poll)(file, retval ? NULL : wait);
+ if (f_op && f_op->poll) {
+ wait_key_set(wait, in, out, bit);
+ mask = (*f_op->poll)(file, wait);
+ }
fput_light(file, fput_needed);
if ((mask & POLLIN_SET) && (in & bit)) {
res_in |= bit;
retval++;
+ wait = NULL;
}
if ((mask & POLLOUT_SET) && (out & bit)) {
res_out |= bit;
retval++;
+ wait = NULL;
}
if ((mask & POLLEX_SET) && (ex & bit)) {
res_ex |= bit;
retval++;
+ wait = NULL;
}
}
- cond_resched();
}
if (res_in)
*rinp = res_in;
*routp = res_out;
if (res_ex)
*rexp = res_ex;
+ cond_resched();
}
wait = NULL;
- if (retval || !*timeout || signal_pending(current))
+ if (retval || timed_out || signal_pending(current))
break;
- if(table.error) {
+ if (table.error) {
retval = table.error;
break;
}
- if (*timeout < 0) {
- /* Wait indefinitely */
- __timeout = MAX_SCHEDULE_TIMEOUT;
- } else if (unlikely(*timeout >= (s64)MAX_SCHEDULE_TIMEOUT - 1)) {
- /* Wait for longer than MAX_SCHEDULE_TIMEOUT. Do it in a loop */
- __timeout = MAX_SCHEDULE_TIMEOUT - 1;
- *timeout -= __timeout;
- } else {
- __timeout = *timeout;
- *timeout = 0;
+ /*
+ * If this is the first loop and we have a timeout
+ * given, then we convert to ktime_t and set the to
+ * pointer to the expiry value.
+ */
+ if (end_time && !to) {
+ expire = timespec_to_ktime(*end_time);
+ to = &expire;
}
- __timeout = schedule_timeout(__timeout);
- if (*timeout >= 0)
- *timeout += __timeout;
+
+ if (!poll_schedule_timeout(&table, TASK_INTERRUPTIBLE,
+ to, slack))
+ timed_out = 1;
}
- __set_current_state(TASK_RUNNING);
poll_freewait(&table);
* Update: ERESTARTSYS breaks at least the xview clock binary, so
* I'm trying ERESTARTNOHAND which restart only when you want to.
*/
-#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,
- fd_set __user *exp, s64 *timeout)
+int core_sys_select(int n, fd_set __user *inp, fd_set __user *outp,
+ fd_set __user *exp, struct timespec *end_time)
{
fd_set_bits fds;
void *bits;
- int ret, max_fdset;
+ int ret, max_fds;
unsigned int size;
struct fdtable *fdt;
/* Allocate small arguments on the stack to save memory and be faster */
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),
zero_fd_set(n, fds.res_out);
zero_fd_set(n, fds.res_ex);
- ret = do_select(n, &fds, timeout);
+ ret = do_select(n, &fds, end_time);
if (ret < 0)
goto out;
return ret;
}
-asmlinkage long sys_select(int n, fd_set __user *inp, fd_set __user *outp,
- fd_set __user *exp, struct timeval __user *tvp)
+SYSCALL_DEFINE5(select, int, n, fd_set __user *, inp, fd_set __user *, outp,
+ fd_set __user *, exp, struct timeval __user *, tvp)
{
- s64 timeout = -1;
+ struct timespec end_time, *to = NULL;
struct timeval tv;
int ret;
if (copy_from_user(&tv, tvp, sizeof(tv)))
return -EFAULT;
- if (tv.tv_sec < 0 || tv.tv_usec < 0)
+ to = &end_time;
+ if (poll_select_set_timeout(to,
+ tv.tv_sec + (tv.tv_usec / USEC_PER_SEC),
+ (tv.tv_usec % USEC_PER_SEC) * NSEC_PER_USEC))
return -EINVAL;
-
- /* Cast to u64 to make GCC stop complaining */
- if ((u64)tv.tv_sec >= (u64)MAX_INT64_SECONDS)
- timeout = -1; /* infinite */
- else {
- timeout = ROUND_UP(tv.tv_usec, USEC_PER_SEC/HZ);
- timeout += tv.tv_sec * HZ;
- }
}
- ret = core_sys_select(n, inp, outp, exp, &timeout);
-
- if (tvp) {
- struct timeval rtv;
-
- if (current->personality & STICKY_TIMEOUTS)
- goto sticky;
- rtv.tv_usec = jiffies_to_usecs(do_div((*(u64*)&timeout), HZ));
- rtv.tv_sec = timeout;
- if (timeval_compare(&rtv, &tv) >= 0)
- rtv = tv;
- if (copy_to_user(tvp, &rtv, sizeof(rtv))) {
-sticky:
- /*
- * If an application puts its timeval in read-only
- * memory, we don't want the Linux-specific update to
- * the timeval to cause a fault after the select has
- * completed successfully. However, because we're not
- * updating the timeval, we can't restart the system
- * call.
- */
- if (ret == -ERESTARTNOHAND)
- ret = -EINTR;
- }
- }
+ ret = core_sys_select(n, inp, outp, exp, to);
+ ret = poll_select_copy_remaining(&end_time, tvp, 1, ret);
return ret;
}
-#ifdef TIF_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)
+#ifdef HAVE_SET_RESTORE_SIGMASK
+static long do_pselect(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)
{
- s64 timeout = MAX_SCHEDULE_TIMEOUT;
sigset_t ksigmask, sigsaved;
- struct timespec ts;
+ struct timespec ts, end_time, *to = NULL;
int ret;
if (tsp) {
if (copy_from_user(&ts, tsp, sizeof(ts)))
return -EFAULT;
- if (ts.tv_sec < 0 || ts.tv_nsec < 0)
+ to = &end_time;
+ if (poll_select_set_timeout(to, ts.tv_sec, ts.tv_nsec))
return -EINVAL;
-
- /* Cast to u64 to make GCC stop complaining */
- if ((u64)ts.tv_sec >= (u64)MAX_INT64_SECONDS)
- timeout = -1; /* infinite */
- else {
- timeout = ROUND_UP(ts.tv_nsec, NSEC_PER_SEC/HZ);
- timeout += ts.tv_sec * HZ;
- }
}
if (sigmask) {
sigprocmask(SIG_SETMASK, &ksigmask, &sigsaved);
}
- ret = core_sys_select(n, inp, outp, exp, &timeout);
-
- if (tsp) {
- struct timespec rts;
-
- if (current->personality & STICKY_TIMEOUTS)
- goto sticky;
- rts.tv_nsec = jiffies_to_usecs(do_div((*(u64*)&timeout), HZ)) *
- 1000;
- rts.tv_sec = timeout;
- if (timespec_compare(&rts, &ts) >= 0)
- rts = ts;
- if (copy_to_user(tsp, &rts, sizeof(rts))) {
-sticky:
- /*
- * If an application puts its timeval in read-only
- * memory, we don't want the Linux-specific update to
- * the timeval to cause a fault after the select has
- * completed successfully. However, because we're not
- * updating the timeval, we can't restart the system
- * call.
- */
- if (ret == -ERESTARTNOHAND)
- ret = -EINTR;
- }
- }
+ ret = core_sys_select(n, inp, outp, exp, to);
+ ret = poll_select_copy_remaining(&end_time, tsp, 0, ret);
if (ret == -ERESTARTNOHAND) {
/*
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);
* which has a pointer to the sigset_t itself followed by a size_t containing
* the sigset size.
*/
-asmlinkage long sys_pselect6(int n, fd_set __user *inp, fd_set __user *outp,
- fd_set __user *exp, struct timespec __user *tsp, void __user *sig)
+SYSCALL_DEFINE6(pselect6, int, n, fd_set __user *, inp, fd_set __user *, outp,
+ fd_set __user *, exp, struct timespec __user *, tsp,
+ void __user *, sig)
{
size_t sigsetsize = 0;
sigset_t __user *up = NULL;
return -EFAULT;
}
- return sys_pselect7(n, inp, outp, exp, tsp, up, sigsetsize);
+ return do_pselect(n, inp, outp, exp, tsp, up, sigsetsize);
+}
+#endif /* HAVE_SET_RESTORE_SIGMASK */
+
+#ifdef __ARCH_WANT_SYS_OLD_SELECT
+struct sel_arg_struct {
+ unsigned long n;
+ fd_set __user *inp, *outp, *exp;
+ struct timeval __user *tvp;
+};
+
+SYSCALL_DEFINE1(old_select, struct sel_arg_struct __user *, arg)
+{
+ struct sel_arg_struct a;
+
+ if (copy_from_user(&a, arg, sizeof(a)))
+ return -EFAULT;
+ return sys_select(a.n, a.inp, a.outp, a.exp, a.tvp);
}
-#endif /* TIF_RESTORE_SIGMASK */
+#endif
struct poll_list {
struct poll_list *next;
mask = POLLNVAL;
if (file != NULL) {
mask = DEFAULT_POLLMASK;
- if (file->f_op && file->f_op->poll)
+ if (file->f_op && file->f_op->poll) {
+ if (pwait)
+ pwait->key = pollfd->events |
+ POLLERR | POLLHUP;
mask = file->f_op->poll(file, pwait);
+ }
/* Mask out unneeded events. */
mask &= pollfd->events | POLLERR | POLLHUP;
fput_light(file, fput_needed);
}
static int do_poll(unsigned int nfds, struct poll_list *list,
- struct poll_wqueues *wait, s64 *timeout)
+ struct poll_wqueues *wait, struct timespec *end_time)
{
- int count = 0;
poll_table* pt = &wait->pt;
+ ktime_t expire, *to = NULL;
+ int timed_out = 0, count = 0;
+ unsigned long slack = 0;
/* Optimise the no-wait case */
- if (!(*timeout))
+ if (end_time && !end_time->tv_sec && !end_time->tv_nsec) {
pt = NULL;
-
+ timed_out = 1;
+ }
+
+ if (end_time && !timed_out)
+ slack = select_estimate_accuracy(end_time);
+
for (;;) {
struct poll_list *walk;
- long __timeout;
- set_current_state(TASK_INTERRUPTIBLE);
for (walk = list; walk != NULL; walk = walk->next) {
struct pollfd * pfd, * pfd_end;
* 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 || timed_out)
break;
- if (*timeout < 0) {
- /* Wait indefinitely */
- __timeout = MAX_SCHEDULE_TIMEOUT;
- } else if (unlikely(*timeout >= (s64)MAX_SCHEDULE_TIMEOUT-1)) {
- /*
- * Wait for longer than MAX_SCHEDULE_TIMEOUT. Do it in
- * a loop
- */
- __timeout = MAX_SCHEDULE_TIMEOUT - 1;
- *timeout -= __timeout;
- } else {
- __timeout = *timeout;
- *timeout = 0;
+ /*
+ * If this is the first loop and we have a timeout
+ * given, then we convert to ktime_t and set the to
+ * pointer to the expiry value.
+ */
+ if (end_time && !to) {
+ expire = timespec_to_ktime(*end_time);
+ to = &expire;
}
- __timeout = schedule_timeout(__timeout);
- if (*timeout >= 0)
- *timeout += __timeout;
+ if (!poll_schedule_timeout(wait, TASK_INTERRUPTIBLE, to, slack))
+ timed_out = 1;
}
- __set_current_state(TASK_RUNNING);
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)
+int do_sys_poll(struct pollfd __user *ufds, unsigned int nfds,
+ struct timespec *end_time)
{
struct poll_wqueues table;
- int fdcount, err;
- unsigned int i;
- struct poll_list *head;
- struct poll_list *walk;
+ 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 *stack_pp = NULL;
+ struct poll_list *const head = (struct poll_list *)stack_pps;
+ struct poll_list *walk = head;
+ unsigned long todo = nfds;
- /* Do a sanity check on nfds ... */
- if (nfds > current->signal->rlim[RLIMIT_NOFILE].rlim_cur)
+ if (nfds > rlimit(RLIMIT_NOFILE))
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;
- int num, size;
- if (stack_pp == NULL)
- num = N_STACK_PPS;
- else
- num = POLLFD_PER_PAGE;
- if (num > i)
- num = i;
- size = sizeof(struct poll_list) + sizeof(struct pollfd)*num;
- if (!stack_pp)
- stack_pp = pp = (struct poll_list *)stack_pps;
- else {
- pp = kmalloc(size, GFP_KERNEL);
- if (!pp)
- goto out_fds;
- }
- pp->next=NULL;
- pp->len = num;
- if (head == NULL)
- head = pp;
- else
- walk->next = pp;
-
- walk = pp;
- if (copy_from_user(pp->entries, ufds + nfds-i,
- sizeof(struct pollfd)*num)) {
- err = -EFAULT;
+ if (copy_from_user(walk->entries, ufds + nfds-todo,
+ sizeof(struct pollfd) * walk->len))
+ goto out_fds;
+
+ 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;
}
- fdcount = do_poll(nfds, head, &table, timeout);
+ poll_initwait(&table);
+ fdcount = do_poll(nfds, head, &table, end_time);
+ 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;
- if (walk != stack_pp)
- kfree(walk);
- walk = pp;
+ walk = head->next;
+ while (walk) {
+ struct poll_list *pos = walk;
+ walk = walk->next;
+ kfree(pos);
}
- poll_freewait(&table);
+
return err;
}
-asmlinkage long sys_poll(struct pollfd __user *ufds, unsigned int nfds,
- long timeout_msecs)
+static long do_restart_poll(struct restart_block *restart_block)
{
- s64 timeout_jiffies;
-
- 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);
- } else {
- /* Infinite (< 0) or no (0) timeout */
- timeout_jiffies = timeout_msecs;
+ struct pollfd __user *ufds = restart_block->poll.ufds;
+ int nfds = restart_block->poll.nfds;
+ struct timespec *to = NULL, end_time;
+ int ret;
+
+ if (restart_block->poll.has_timeout) {
+ end_time.tv_sec = restart_block->poll.tv_sec;
+ end_time.tv_nsec = restart_block->poll.tv_nsec;
+ to = &end_time;
}
- return do_sys_poll(ufds, nfds, &timeout_jiffies);
+ ret = do_sys_poll(ufds, nfds, to);
+
+ if (ret == -EINTR) {
+ restart_block->fn = do_restart_poll;
+ ret = -ERESTART_RESTARTBLOCK;
+ }
+ return ret;
+}
+
+SYSCALL_DEFINE3(poll, struct pollfd __user *, ufds, unsigned int, nfds,
+ long, timeout_msecs)
+{
+ struct timespec end_time, *to = NULL;
+ int ret;
+
+ if (timeout_msecs >= 0) {
+ to = &end_time;
+ poll_select_set_timeout(to, timeout_msecs / MSEC_PER_SEC,
+ NSEC_PER_MSEC * (timeout_msecs % MSEC_PER_SEC));
+ }
+
+ ret = do_sys_poll(ufds, nfds, to);
+
+ if (ret == -EINTR) {
+ struct restart_block *restart_block;
+
+ restart_block = ¤t_thread_info()->restart_block;
+ restart_block->fn = do_restart_poll;
+ restart_block->poll.ufds = ufds;
+ restart_block->poll.nfds = nfds;
+
+ if (timeout_msecs >= 0) {
+ restart_block->poll.tv_sec = end_time.tv_sec;
+ restart_block->poll.tv_nsec = end_time.tv_nsec;
+ restart_block->poll.has_timeout = 1;
+ } else
+ restart_block->poll.has_timeout = 0;
+
+ ret = -ERESTART_RESTARTBLOCK;
+ }
+ return ret;
}
-#ifdef TIF_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)
+#ifdef HAVE_SET_RESTORE_SIGMASK
+SYSCALL_DEFINE5(ppoll, struct pollfd __user *, ufds, unsigned int, nfds,
+ struct timespec __user *, tsp, const sigset_t __user *, sigmask,
+ size_t, sigsetsize)
{
sigset_t ksigmask, sigsaved;
- struct timespec ts;
- s64 timeout = -1;
+ struct timespec ts, end_time, *to = NULL;
int ret;
if (tsp) {
if (copy_from_user(&ts, tsp, sizeof(ts)))
return -EFAULT;
- /* Cast to u64 to make GCC stop complaining */
- if ((u64)ts.tv_sec >= (u64)MAX_INT64_SECONDS)
- timeout = -1; /* infinite */
- else {
- timeout = ROUND_UP(ts.tv_nsec, NSEC_PER_SEC/HZ);
- timeout += ts.tv_sec * HZ;
- }
+ to = &end_time;
+ if (poll_select_set_timeout(to, ts.tv_sec, ts.tv_nsec))
+ return -EINVAL;
}
if (sigmask) {
sigprocmask(SIG_SETMASK, &ksigmask, &sigsaved);
}
- ret = do_sys_poll(ufds, nfds, &timeout);
+ ret = do_sys_poll(ufds, nfds, to);
/* We can restart this syscall, usually */
if (ret == -EINTR) {
if (sigmask) {
memcpy(¤t->saved_sigmask, &sigsaved,
sizeof(sigsaved));
- set_thread_flag(TIF_RESTORE_SIGMASK);
+ set_restore_sigmask();
}
ret = -ERESTARTNOHAND;
} else if (sigmask)
sigprocmask(SIG_SETMASK, &sigsaved, NULL);
- if (tsp && timeout >= 0) {
- struct timespec rts;
-
- if (current->personality & STICKY_TIMEOUTS)
- goto sticky;
- /* Yes, we know it's actually an s64, but it's also positive. */
- rts.tv_nsec = jiffies_to_usecs(do_div((*(u64*)&timeout), HZ)) *
- 1000;
- rts.tv_sec = timeout;
- if (timespec_compare(&rts, &ts) >= 0)
- rts = ts;
- if (copy_to_user(tsp, &rts, sizeof(rts))) {
- sticky:
- /*
- * If an application puts its timeval in read-only
- * memory, we don't want the Linux-specific update to
- * the timeval to cause a fault after the select has
- * completed successfully. However, because we're not
- * updating the timeval, we can't restart the system
- * call.
- */
- if (ret == -ERESTARTNOHAND && timeout >= 0)
- ret = -EINTR;
- }
- }
+ ret = poll_select_copy_remaining(&end_time, tsp, 0, ret);
return ret;
}
-#endif /* TIF_RESTORE_SIGMASK */
+#endif /* HAVE_SET_RESTORE_SIGMASK */
Code Review / linux-2.6.git / blobdiff