input: misc: Changed sysfs permissions
[linux-2.6.git] / fs / select.c
index 08b91be..0baa0a3 100644 (file)
@@ -15,8 +15,9 @@
  */
 
 #include <linux/kernel.h>
+#include <linux/sched.h>
 #include <linux/syscalls.h>
-#include <linux/module.h>
+#include <linux/export.h>
 #include <linux/slab.h>
 #include <linux/poll.h>
 #include <linux/personality.h> /* for STICKY_TIMEOUTS */
  * 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 > 100 * NSEC_PER_MSEC)
-               slack =  100 * NSEC_PER_MSEC;
+       if (slack > MAX_SLACK)
+               return MAX_SLACK;
 
-       if (slack < 0)
-               slack = 0;
        return slack;
 }
 
-static long estimate_accuracy(struct timespec *tv)
+long select_estimate_accuracy(struct timespec *tv)
 {
        unsigned long ret;
        struct timespec now;
@@ -110,6 +117,7 @@ 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;
@@ -168,7 +176,7 @@ static struct poll_table_entry *poll_get_entry(struct poll_wqueues *p)
        return table->entry++;
 }
 
-static int pollwake(wait_queue_t *wait, unsigned mode, int sync, void *key)
+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);
@@ -194,6 +202,16 @@ static int pollwake(wait_queue_t *wait, unsigned mode, int sync, void *key)
        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)
@@ -205,6 +223,7 @@ static void __pollwait(struct file *filp, wait_queue_head_t *wait_address,
        get_file(filp);
        entry->filp = filp;
        entry->wait_address = wait_address;
+       entry->key = p->_key;
        init_waitqueue_func_entry(&entry->wait, pollwake);
        entry->wait.private = pwq;
        add_wait_queue(wait_address, &entry->wait);
@@ -287,6 +306,8 @@ static int poll_select_copy_remaining(struct timespec *end_time, void __user *p,
                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;
 
@@ -324,10 +345,10 @@ static int max_select_fd(unsigned long n, fd_set_bits *fds)
        struct fdtable *fdt;
 
        /* handle last in-complete long-word first */
-       set = ~(~0UL << (n & (__NFDBITS-1)));
-       n /= __NFDBITS;
+       set = ~(~0UL << (n & (BITS_PER_LONG-1)));
+       n /= BITS_PER_LONG;
        fdt = files_fdtable(current->files);
-       open_fds = fdt->open_fds->fds_bits+n;
+       open_fds = fdt->open_fds + n;
        max = 0;
        if (set) {
                set &= BITS(fds, n);
@@ -352,7 +373,7 @@ get_max:
                        max++;
                        set >>= 1;
                } while (set);
-               max += n * __NFDBITS;
+               max += n * BITS_PER_LONG;
        }
 
        return max;
@@ -362,6 +383,16 @@ get_max:
 #define POLLOUT_SET (POLLWRBAND | POLLWRNORM | POLLOUT | POLLERR)
 #define POLLEX_SET (POLLPRI)
 
+static inline void wait_key_set(poll_table *wait, unsigned long in,
+                               unsigned long out, unsigned long bit)
+{
+       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;
@@ -381,12 +412,12 @@ int do_select(int n, fd_set_bits *fds, struct timespec *end_time)
        poll_initwait(&table);
        wait = &table.pt;
        if (end_time && !end_time->tv_sec && !end_time->tv_nsec) {
-               wait = NULL;
+               wait->_qproc = NULL;
                timed_out = 1;
        }
 
        if (end_time && !timed_out)
-               slack = estimate_accuracy(end_time);
+               slack = select_estimate_accuracy(end_time);
 
        retval = 0;
        for (;;) {
@@ -404,11 +435,11 @@ int do_select(int n, fd_set_bits *fds, struct timespec *end_time)
                        in = *inp++; out = *outp++; ex = *exp++;
                        all_bits = in | out | ex;
                        if (all_bits == 0) {
-                               i += __NFDBITS;
+                               i += BITS_PER_LONG;
                                continue;
                        }
 
-                       for (j = 0; j < __NFDBITS; ++j, ++i, bit <<= 1) {
+                       for (j = 0; j < BITS_PER_LONG; ++j, ++i, bit <<= 1) {
                                int fput_needed;
                                if (i >= n)
                                        break;
@@ -418,20 +449,25 @@ int do_select(int n, fd_set_bits *fds, struct timespec *end_time)
                                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->_qproc = NULL;
                                        }
                                        if ((mask & POLLOUT_SET) && (out & bit)) {
                                                res_out |= bit;
                                                retval++;
+                                               wait->_qproc = NULL;
                                        }
                                        if ((mask & POLLEX_SET) && (ex & bit)) {
                                                res_ex |= bit;
                                                retval++;
+                                               wait->_qproc = NULL;
                                        }
                                }
                        }
@@ -443,7 +479,7 @@ int do_select(int n, fd_set_bits *fds, struct timespec *end_time)
                                *rexp = res_ex;
                        cond_resched();
                }
-               wait = NULL;
+               wait->_qproc = NULL;
                if (retval || timed_out || signal_pending(current))
                        break;
                if (table.error) {
@@ -479,9 +515,6 @@ int do_select(int n, fd_set_bits *fds, struct timespec *end_time)
  * 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)
-
 int core_sys_select(int n, fd_set __user *inp, fd_set __user *outp,
                           fd_set __user *exp, struct timespec *end_time)
 {
@@ -557,8 +590,8 @@ out_nofds:
        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)
 {
        struct timespec end_time, *to = NULL;
        struct timeval tv;
@@ -582,9 +615,9 @@ asmlinkage long sys_select(int n, fd_set __user *inp, fd_set __user *outp,
 }
 
 #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)
+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)
 {
        sigset_t ksigmask, sigsaved;
        struct timespec ts, end_time, *to = NULL;
@@ -610,7 +643,7 @@ asmlinkage long sys_pselect7(int n, fd_set __user *inp, fd_set __user *outp,
                sigprocmask(SIG_SETMASK, &ksigmask, &sigsaved);
        }
 
-       ret = core_sys_select(n, inp, outp, exp, &end_time);
+       ret = core_sys_select(n, inp, outp, exp, to);
        ret = poll_select_copy_remaining(&end_time, tsp, 0, ret);
 
        if (ret == -ERESTARTNOHAND) {
@@ -636,8 +669,9 @@ asmlinkage long sys_pselect7(int n, fd_set __user *inp, fd_set __user *outp,
  * 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;
@@ -650,10 +684,27 @@ asmlinkage long sys_pselect6(int n, fd_set __user *inp, fd_set __user *outp,
                        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
+
 struct poll_list {
        struct poll_list *next;
        int len;
@@ -667,7 +718,7 @@ struct poll_list {
  * 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.
+ * if pwait->_qproc is non-NULL.
  */
 static inline unsigned int do_pollfd(struct pollfd *pollfd, poll_table *pwait)
 {
@@ -684,8 +735,10 @@ static inline unsigned int do_pollfd(struct pollfd *pollfd, poll_table *pwait)
                mask = POLLNVAL;
                if (file != NULL) {
                        mask = DEFAULT_POLLMASK;
-                       if (file->f_op && file->f_op->poll)
+                       if (file->f_op && file->f_op->poll) {
+                               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);
@@ -706,12 +759,12 @@ static int do_poll(unsigned int nfds,  struct poll_list *list,
 
        /* Optimise the no-wait case */
        if (end_time && !end_time->tv_sec && !end_time->tv_nsec) {
-               pt = NULL;
+               pt->_qproc = NULL;
                timed_out = 1;
        }
 
        if (end_time && !timed_out)
-               slack = estimate_accuracy(end_time);
+               slack = select_estimate_accuracy(end_time);
 
        for (;;) {
                struct poll_list *walk;
@@ -724,22 +777,22 @@ static int do_poll(unsigned int nfds,  struct poll_list *list,
                        for (; pfd != pfd_end; pfd++) {
                                /*
                                 * Fish for events. If we found one, record it
-                                * and kill the poll_table, so we don't
+                                * and kill poll_table->_qproc, 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;
+                                       pt->_qproc = NULL;
                                }
                        }
                }
                /*
                 * All waiters have already been registered, so don't provide
-                * a poll_table to them on the next loop iteration.
+                * a poll_table->_qproc to them on the next loop iteration.
                 */
-               pt = NULL;
+               pt->_qproc = NULL;
                if (!count) {
                        count = wait->error;
                        if (signal_pending(current))
@@ -780,7 +833,7 @@ int do_sys_poll(struct pollfd __user *ufds, unsigned int nfds,
        struct poll_list *walk = head;
        unsigned long todo = nfds;
 
-       if (nfds > current->signal->rlim[RLIMIT_NOFILE].rlim_cur)
+       if (nfds > rlimit(RLIMIT_NOFILE))
                return -EINVAL;
 
        len = min_t(unsigned int, nfds, N_STACK_PPS);
@@ -854,8 +907,8 @@ static long do_restart_poll(struct restart_block *restart_block)
        return ret;
 }
 
-asmlinkage long sys_poll(struct pollfd __user *ufds, unsigned int nfds,
-                       long timeout_msecs)
+SYSCALL_DEFINE3(poll, struct pollfd __user *, ufds, unsigned int, nfds,
+               int, timeout_msecs)
 {
        struct timespec end_time, *to = NULL;
        int ret;
@@ -889,9 +942,9 @@ asmlinkage long sys_poll(struct pollfd __user *ufds, unsigned int nfds,
 }
 
 #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)
+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, end_time, *to = NULL;