| /* |
| * This file contains the procedures for the handling of select and poll |
| * |
| * Created for Linux based loosely upon Mathius Lattner's minix |
| * patches by Peter MacDonald. Heavily edited by Linus. |
| * |
| * 4 February 1994 |
| * COFF/ELF binary emulation. If the process has the STICKY_TIMEOUTS |
| * flag set in its personality we do *not* modify the given timeout |
| * parameter to reflect time remaining. |
| * |
| * 24 January 2000 |
| * Changed sys_poll()/do_poll() to use PAGE_SIZE chunk-based allocation |
| * 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/poll.h> |
| #include <linux/personality.h> /* for STICKY_TIMEOUTS */ |
| #include <linux/file.h> |
| #include <linux/fs.h> |
| #include <linux/rcupdate.h> |
| |
| #include <asm/uaccess.h> |
| |
| struct poll_table_page { |
| struct poll_table_page * next; |
| struct poll_table_entry * entry; |
| struct poll_table_entry entries[0]; |
| }; |
| |
| #define POLL_TABLE_FULL(table) \ |
| ((unsigned long)((table)->entry+1) > PAGE_SIZE + (unsigned long)(table)) |
| |
| /* |
| * Ok, Peter made a complicated, but straightforward multiple_wait() function. |
| * I have rewritten this, taking some shortcuts: This code may not be easy to |
| * follow, but it should be free of race-conditions, and it's practical. If you |
| * understand what I'm doing here, then you understand how the linux |
| * sleep/wakeup mechanism works. |
| * |
| * Two very simple procedures, poll_wait() and poll_freewait() make all the |
| * work. poll_wait() is an inline-function defined in <linux/poll.h>, |
| * as all select/poll functions have to call it to add an entry to the |
| * poll table. |
| */ |
| static void __pollwait(struct file *filp, wait_queue_head_t *wait_address, |
| poll_table *p); |
| |
| void poll_initwait(struct poll_wqueues *pwq) |
| { |
| 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--; |
| free_poll_entry(entry); |
| } while (entry > p->entries); |
| old = p; |
| p = p->next; |
| free_page((unsigned long) old); |
| } |
| } |
| |
| EXPORT_SYMBOL(poll_freewait); |
| |
| 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; |
| |
| 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; |
| new_table->next = table; |
| p->table = new_table; |
| table = new_table; |
| } |
| |
| 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) |
| #define FDS_OUT(fds, n) (fds->out + n) |
| #define FDS_EX(fds, n) (fds->ex + n) |
| |
| #define BITS(fds, n) (*FDS_IN(fds, n)|*FDS_OUT(fds, n)|*FDS_EX(fds, n)) |
| |
| static int max_select_fd(unsigned long n, fd_set_bits *fds) |
| { |
| unsigned long *open_fds; |
| unsigned long set; |
| int max; |
| struct fdtable *fdt; |
| |
| /* handle last in-complete long-word first */ |
| set = ~(~0UL << (n & (__NFDBITS-1))); |
| n /= __NFDBITS; |
| fdt = files_fdtable(current->files); |
| open_fds = fdt->open_fds->fds_bits+n; |
| max = 0; |
| if (set) { |
| set &= BITS(fds, n); |
| if (set) { |
| if (!(set & ~*open_fds)) |
| goto get_max; |
| return -EBADF; |
| } |
| } |
| while (n) { |
| open_fds--; |
| n--; |
| set = BITS(fds, n); |
| if (!set) |
| continue; |
| if (set & ~*open_fds) |
| return -EBADF; |
| if (max) |
| continue; |
| get_max: |
| do { |
| max++; |
| set >>= 1; |
| } while (set); |
| max += n * __NFDBITS; |
| } |
| |
| 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) |
| { |
| struct poll_wqueues table; |
| poll_table *wait; |
| int retval, i; |
| |
| rcu_read_lock(); |
| retval = max_select_fd(n, fds); |
| rcu_read_unlock(); |
| |
| if (retval < 0) |
| return retval; |
| n = retval; |
| |
| poll_initwait(&table); |
| wait = &table.pt; |
| if (!*timeout) |
| wait = NULL; |
| 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; |
| |
| 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; |
| const struct file_operations *f_op = NULL; |
| struct file *file = NULL; |
| |
| in = *inp++; out = *outp++; ex = *exp++; |
| all_bits = in | out | ex; |
| if (all_bits == 0) { |
| i += __NFDBITS; |
| continue; |
| } |
| |
| for (j = 0; j < __NFDBITS; ++j, ++i, bit <<= 1) { |
| int fput_needed; |
| if (i >= n) |
| break; |
| if (!(bit & all_bits)) |
| continue; |
| 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_light(file, fput_needed); |
| if ((mask & POLLIN_SET) && (in & bit)) { |
| res_in |= bit; |
| retval++; |
| } |
| if ((mask & POLLOUT_SET) && (out & bit)) { |
| res_out |= bit; |
| retval++; |
| } |
| if ((mask & POLLEX_SET) && (ex & bit)) { |
| res_ex |= bit; |
| retval++; |
| } |
| } |
| cond_resched(); |
| } |
| if (res_in) |
| *rinp = res_in; |
| if (res_out) |
| *routp = res_out; |
| if (res_ex) |
| *rexp = res_ex; |
| } |
| wait = NULL; |
| if (retval || !*timeout || 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; |
| } |
| __timeout = schedule_timeout(__timeout); |
| if (*timeout >= 0) |
| *timeout += __timeout; |
| } |
| __set_current_state(TASK_RUNNING); |
| |
| poll_freewait(&table); |
| |
| return retval; |
| } |
| |
| /* |
| * We can actually return ERESTARTSYS instead of EINTR, but I'd |
| * like to be certain this leads to no problems. So I return |
| * EINTR just for safety. |
| * |
| * 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) |
| { |
| fd_set_bits fds; |
| 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_fds can increase, so grab it once to avoid race */ |
| rcu_read_lock(); |
| fdt = files_fdtable(current->files); |
| max_fds = fdt->max_fds; |
| rcu_read_unlock(); |
| 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. |
| */ |
| size = FDS_BYTES(n); |
| 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 = get_fd_set(n, exp, fds.ex))) |
| goto out; |
| zero_fd_set(n, fds.res_in); |
| zero_fd_set(n, fds.res_out); |
| zero_fd_set(n, fds.res_ex); |
| |
| ret = do_select(n, &fds, timeout); |
| |
| if (ret < 0) |
| goto out; |
| if (!ret) { |
| ret = -ERESTARTNOHAND; |
| if (signal_pending(current)) |
| goto out; |
| ret = 0; |
| } |
| |
| if (set_fd_set(n, inp, fds.res_in) || |
| set_fd_set(n, outp, fds.res_out) || |
| set_fd_set(n, exp, fds.res_ex)) |
| ret = -EFAULT; |
| |
| out: |
| if (bits != stack_fds) |
| kfree(bits); |
| 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) |
| { |
| s64 timeout = -1; |
| struct timeval tv; |
| int ret; |
| |
| if (tvp) { |
| if (copy_from_user(&tv, tvp, sizeof(tv))) |
| return -EFAULT; |
| |
| if (tv.tv_sec < 0 || tv.tv_usec < 0) |
| 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; |
| } |
| } |
| |
| 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) |
| { |
| s64 timeout = MAX_SCHEDULE_TIMEOUT; |
| sigset_t ksigmask, sigsaved; |
| struct timespec ts; |
| int ret; |
| |
| if (tsp) { |
| if (copy_from_user(&ts, tsp, sizeof(ts))) |
| return -EFAULT; |
| |
| if (ts.tv_sec < 0 || ts.tv_nsec < 0) |
| 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) { |
| /* XXX: Don't preclude handling different sized sigset_t's. */ |
| if (sigsetsize != sizeof(sigset_t)) |
| return -EINVAL; |
| if (copy_from_user(&ksigmask, sigmask, sizeof(ksigmask))) |
| return -EFAULT; |
| |
| sigdelsetmask(&ksigmask, sigmask(SIGKILL)|sigmask(SIGSTOP)); |
| 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; |
| } |
| } |
| |
| if (ret == -ERESTARTNOHAND) { |
| /* |
| * Don't restore the signal mask yet. Let do_signal() deliver |
| * the signal on the way back to userspace, before the signal |
| * mask is restored. |
| */ |
| if (sigmask) { |
| memcpy(¤t->saved_sigmask, &sigsaved, |
| sizeof(sigsaved)); |
| set_thread_flag(TIF_RESTORE_SIGMASK); |
| } |
| } else if (sigmask) |
| sigprocmask(SIG_SETMASK, &sigsaved, NULL); |
| |
| return ret; |
| } |
| |
| /* |
| * Most architectures can't handle 7-argument syscalls. So we provide a |
| * 6-argument version where the sixth argument is a pointer to a structure |
| * 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) |
| { |
| size_t sigsetsize = 0; |
| sigset_t __user *up = NULL; |
| |
| if (sig) { |
| if (!access_ok(VERIFY_READ, sig, sizeof(void *)+sizeof(size_t)) |
| || __get_user(up, (sigset_t __user * __user *)sig) |
| || __get_user(sigsetsize, |
| (size_t __user *)(sig+sizeof(void *)))) |
| return -EFAULT; |
| } |
| |
| return sys_pselect7(n, inp, outp, exp, tsp, up, sigsetsize); |
| } |
| #endif /* TIF_RESTORE_SIGMASK */ |
| |
| struct poll_list { |
| struct poll_list *next; |
| int len; |
| struct pollfd entries[0]; |
| }; |
| |
| #define POLLFD_PER_PAGE ((PAGE_SIZE-sizeof(struct poll_list)) / sizeof(struct pollfd)) |
| |
| /* |
| * 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) |
| { |
| 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); |
| } |
| } |
| pollfd->revents = mask; |
| |
| return mask; |
| } |
| |
| static int do_poll(unsigned int nfds, struct poll_list *list, |
| struct poll_wqueues *wait, s64 *timeout) |
| { |
| int count = 0; |
| poll_table* pt = &wait->pt; |
| |
| /* Optimise the no-wait case */ |
| if (!(*timeout)) |
| pt = NULL; |
| |
| 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; |
| |
| 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) |
| 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; |
| } |
| |
| __timeout = schedule_timeout(__timeout); |
| if (*timeout >= 0) |
| *timeout += __timeout; |
| } |
| __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) |
| { |
| struct poll_wqueues table; |
| 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; |
| |
| len = min_t(unsigned int, nfds, N_STACK_PPS); |
| for (;;) { |
| walk->next = NULL; |
| walk->len = len; |
| if (!len) |
| break; |
| |
| 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; |
| } |
| } |
| |
| poll_initwait(&table); |
| fdcount = do_poll(nfds, head, &table, timeout); |
| if (!fdcount && signal_pending(current)) |
| fdcount = -EINTR; |
| poll_freewait(&table); |
| |
| 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)) |
| goto out_fds; |
| } |
| |
| err = fdcount; |
| out_fds: |
| walk = head->next; |
| while (walk) { |
| struct poll_list *pos = walk; |
| walk = walk->next; |
| kfree(pos); |
| } |
| |
| return err; |
| } |
| |
| asmlinkage long sys_poll(struct pollfd __user *ufds, unsigned int nfds, |
| long timeout_msecs) |
| { |
| 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; |
| } |
| |
| return do_sys_poll(ufds, nfds, &timeout_jiffies); |
| } |
| |
| #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) |
| { |
| sigset_t ksigmask, sigsaved; |
| struct timespec ts; |
| s64 timeout = -1; |
| 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; |
| } |
| } |
| |
| if (sigmask) { |
| /* XXX: Don't preclude handling different sized sigset_t's. */ |
| if (sigsetsize != sizeof(sigset_t)) |
| return -EINVAL; |
| if (copy_from_user(&ksigmask, sigmask, sizeof(ksigmask))) |
| return -EFAULT; |
| |
| sigdelsetmask(&ksigmask, sigmask(SIGKILL)|sigmask(SIGSTOP)); |
| sigprocmask(SIG_SETMASK, &ksigmask, &sigsaved); |
| } |
| |
| ret = do_sys_poll(ufds, nfds, &timeout); |
| |
| /* We can restart this syscall, usually */ |
| if (ret == -EINTR) { |
| /* |
| * Don't restore the signal mask yet. Let do_signal() deliver |
| * the signal on the way back to userspace, before the signal |
| * mask is restored. |
| */ |
| if (sigmask) { |
| memcpy(¤t->saved_sigmask, &sigsaved, |
| sizeof(sigsaved)); |
| set_thread_flag(TIF_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; |
| } |
| } |
| |
| return ret; |
| } |
| #endif /* TIF_RESTORE_SIGMASK */ |