Clean up and fix fast select case

diff --git a/fs/select.c b/fs/select.c
index 6a5909a75677acc1041b1484f3ce3a73c0ea3da1..9fd7fb13620074dc3b2585ef4f1c9521b3fc31a1 100644 (file)
--- a/fs/select.c
+++ b/fs/select.c
@@ -120,7 +120,7 @@ void __pollwait(struct file * filp, wait_queue_head_t * wait_address, poll_table
 int do_select(int n, fd_set_bits *fds, long *timeout)
 {
        poll_table table, *wait;
-       int retval, off, max, maxoff;
+       int retval, off, maxoff;
        long __timeout = *timeout;
 
        poll_initwait(&table);
@@ -129,27 +129,25 @@ int do_select(int n, fd_set_bits *fds, long *timeout)
                wait = NULL;
        
        retval = 0;
-       maxoff = n/BITS_PER_LONG; 
-       max = 0; 
+       maxoff = FDS_LONGS(n);
        for (;;) {
                set_current_state(TASK_INTERRUPTIBLE);
                for (off = 0; off <= maxoff; off++) { 
                        unsigned long val = BITS(fds, off); 
 
-                       if (!val) 
-                               continue;
                        while (val) { 
-                               int k = ffz(~val); 
+                               int k = ffz(~val), index; 
                                unsigned long mask, bit;
                                struct file *file;
 
-                               if (k > n%BITS_PER_LONG) 
-                                       break;
-
                                bit = (1UL << k); 
                                val &= ~bit; 
 
-                               file = fget((off * BITS_PER_LONG) + k);
+                               index = off*BITS_PER_LONG + k;
+                               if (index >= n) 
+                                       break;
+
+                               file = fget(index);
                                mask = POLLNVAL;
                                if (file) {
                                        mask = DEFAULT_POLLMASK;
@@ -167,7 +165,7 @@ int do_select(int n, fd_set_bits *fds, long *timeout)
                                        retval++;
                                        wait = NULL;
                                }
-                               if ((mask& POLLOUT_SET) && ISSET(bit,__OUT(fds,off))) {
+                               if ((mask & POLLOUT_SET) && ISSET(bit,__OUT(fds,off))) {
                                        SET(bit, __RES_OUT(fds,off));
                                        retval++;
                                        wait = NULL;
@@ -177,18 +175,13 @@ int do_select(int n, fd_set_bits *fds, long *timeout)
                                        retval++;
                                        wait = NULL;
                                }
-
-                               if (!(val &= ~bit))
-                                       break;
                        }
                }
 
-               
-               maxoff = max; 
                wait = NULL;
                if (retval || !__timeout || signal_pending(current))
                        break;
-               if(table.error) {
+               if (table.error) {
                        retval = table.error;
                        break;
                }
@@ -214,19 +207,15 @@ out:
 
 static int get_fd_set(unsigned long nr, void *ufdset, unsigned long *fdset)
 {
-       unsigned long rounded = FDS_BYTES(nr), mask; 
+       unsigned long rounded = FDS_BYTES(nr);
        if (ufdset) {
                int error = verify_area(VERIFY_WRITE, ufdset, rounded);
                if (!error && __copy_from_user(fdset, ufdset, rounded))
                        error = -EFAULT;
-               if (nr % __NFDBITS == 0) 
-                       mask = 0;
-               else { 
-                       /* This includes one bit too much according to SU;
-                          but without this some programs hang. */ 
-                       mask = ~(~0UL << (nr%__NFDBITS)); 
+               if (nr % __NFDBITS) {
+                       unsigned long mask = ~(~0UL << (nr % __NFDBITS)); 
+                       fdset[nr/__NFDBITS] &= mask; 
                } 
-               fdset[nr/__NFDBITS] &= mask; 
                return error;
        }
        memset(fdset, 0, rounded);
@@ -248,10 +237,10 @@ asmlinkage long
 sys_select(int n, fd_set *inp, fd_set *outp, fd_set *exp, struct timeval *tvp)
 {
        fd_set_bits fds;
-       char *bits;
+       unsigned long *bits;
        long timeout;
        int ret, size, max_fdset;
-       char stack_bits[FDS_BYTES(FAST_SELECT_MAX) * 6]; 
+       unsigned long stack_bits[FDS_LONGS(FAST_SELECT_MAX) * 6]; 
 
        timeout = MAX_SCHEDULE_TIMEOUT;
        if (tvp) {
@@ -286,22 +275,21 @@ sys_select(int n, fd_set *inp, fd_set *outp, fd_set *exp, struct timeval *tvp)
         * since we used fdset we need to allocate memory in units of
         * long-words. 
         */
-       size = FDS_BYTES(n);
-       if (n < FAST_SELECT_MAX) { 
-               bits = stack_bits;
-       } else { 
+       size = FDS_LONGS(n);
+       bits = stack_bits;
+       if (n >= FAST_SELECT_MAX) { 
                ret = -ENOMEM;
-               bits = kmalloc(6*size, GFP_KERNEL);
+               bits = kmalloc(sizeof(unsigned long)*6*size, GFP_KERNEL);
                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);
+       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)) ||