#include <linux/fdtable.h>
#include <linux/fs.h>
#include <linux/rcupdate.h>
+#include <linux/hrtimer.h>
#include <asm/uaccess.h>
+
+/*
+ * 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..
+ */
+
+static long __estimate_accuracy(struct timespec *tv)
+{
+ long slack;
+ int divfactor = 1000;
+
+ if (task_nice(current) > 0)
+ divfactor = divfactor / 5;
+
+ slack = tv->tv_nsec / divfactor;
+ slack += tv->tv_sec * (NSEC_PER_SEC/divfactor);
+
+ if (slack > 100 * NSEC_PER_MSEC)
+ slack = 100 * NSEC_PER_MSEC;
+
+ if (slack < 0)
+ slack = 0;
+ return slack;
+}
+
+static long 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;
struct poll_table_entry * entry;
add_wait_queue(wait_address, &entry->wait);
}
+/**
+ * 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) {
+ 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)
#define FDS_OUT(fds, n) (fds->out + n)
#define FDS_EX(fds, n) (fds->ex + n)
#define POLLOUT_SET (POLLWRBAND | POLLWRNORM | POLLOUT | POLLERR)
#define POLLEX_SET (POLLPRI)
-int do_select(int n, fd_set_bits *fds, s64 *timeout)
+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 = estimate_accuracy(end_time);
+
retval = 0;
for (;;) {
unsigned long *rinp, *routp, *rexp, *inp, *outp, *exp;
- long __timeout;
set_current_state(TASK_INTERRUPTIBLE);
cond_resched();
}
wait = NULL;
- if (retval || !*timeout || signal_pending(current))
+ if (retval || timed_out || signal_pending(current))
break;
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 (!schedule_hrtimeout_range(to, slack, HRTIMER_MODE_ABS))
+ timed_out = 1;
}
__set_current_state(TASK_RUNNING);
((unsigned long) (MAX_SCHEDULE_TIMEOUT / HZ)-1)
int core_sys_select(int n, fd_set __user *inp, fd_set __user *outp,
- fd_set __user *exp, s64 *timeout)
+ fd_set __user *exp, struct timespec *end_time)
{
fd_set_bits fds;
void *bits;
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;
asmlinkage long sys_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 = DIV_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;
}
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 = DIV_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, &end_time);
+ ret = poll_select_copy_remaining(&end_time, tsp, 0, ret);
if (ret == -ERESTARTNOHAND) {
/*
}
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 = estimate_accuracy(end_time);
for (;;) {
struct poll_list *walk;
- long __timeout;
set_current_state(TASK_INTERRUPTIBLE);
for (walk = list; walk != NULL; walk = walk->next) {
if (signal_pending(current))
count = -EINTR;
}
- if (count || !*timeout)
+ 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 (!schedule_hrtimeout_range(to, slack, HRTIMER_MODE_ABS))
+ 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 err = -EFAULT, fdcount, len, size;
}
poll_initwait(&table);
- fdcount = do_poll(nfds, head, &table, timeout);
+ fdcount = do_poll(nfds, head, &table, end_time);
poll_freewait(&table);
for (walk = head; walk; walk = walk->next) {
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;
+ struct pollfd __user *ufds = restart_block->poll.ufds;
+ int nfds = restart_block->poll.nfds;
+ struct timespec *to = NULL, end_time;
int ret;
- ret = do_sys_poll(ufds, nfds, &timeout);
+ 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;
+ }
+
+ ret = do_sys_poll(ufds, nfds, to);
+
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;
+ struct timespec end_time, *to = NULL;
int ret;
- 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) + 1;
- } else {
- /* Infinite (< 0) or no (0) timeout */
- timeout_jiffies = timeout_msecs;
+ 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, &timeout_jiffies);
+ 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->arg0 = (unsigned long)ufds;
- restart_block->arg1 = nfds;
- restart_block->arg2 = timeout_jiffies & 0xFFFFFFFF;
- restart_block->arg3 = (u64)timeout_jiffies >> 32;
+ 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;
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 = DIV_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) {
} 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;
}
git.openpandora.org / pandora-kernel.git / blobdiff