X-Git-Url: http://git.onelab.eu/?a=blobdiff_plain;f=fs%2Fselect.c;h=8cd6dc31fbb657d34fcf40ad4e6376ec90028947;hb=43bc926fffd92024b46cafaf7350d669ba9ca884;hp=dfff0ad1baf5231e492dc7d1c1f314afaf94adac;hpb=c7b5ebbddf7bcd3651947760f423e3783bbe6573;p=linux-2.6.git diff --git a/fs/select.c b/fs/select.c index dfff0ad1b..8cd6dc31f 100644 --- a/fs/select.c +++ b/fs/select.c @@ -14,6 +14,7 @@ * of fds to overcome nfds < 16390 descriptors limit (Tigran Aivazian). */ +#include #include #include #include @@ -21,18 +22,14 @@ #include /* for STICKY_TIMEOUTS */ #include #include +#include +#include #include #define ROUND_UP(x,y) (((x)+(y)-1)/(y)) #define DEFAULT_POLLMASK (POLLIN | POLLOUT | POLLRDNORM | POLLWRNORM) -struct poll_table_entry { - struct file * filp; - wait_queue_t wait; - wait_queue_head_t * wait_address; -}; - struct poll_table_page { struct poll_table_page * next; struct poll_table_entry * entry; @@ -54,20 +51,32 @@ struct poll_table_page { * as all select/poll functions have to call it to add an entry to the * poll table. */ -void __pollwait(struct file *filp, wait_queue_head_t *wait_address, poll_table *p); +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) +{ + if (remove_wait_queue(entry->wait_address,&entry->wait) < 0) + print_symbol("bad poll-entry for %s", (unsigned long) entry->filp->f_op->poll); + 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; @@ -75,8 +84,7 @@ void poll_freewait(struct poll_wqueues *pwq) entry = p->entry; do { entry--; - remove_wait_queue(entry->wait_address,&entry->wait); - fput(entry->filp); + free_poll_entry(entry); } while (entry > p->entries); old = p; p = p->next; @@ -86,11 +94,14 @@ void poll_freewait(struct poll_wqueues *pwq) EXPORT_SYMBOL(poll_freewait); -void __pollwait(struct file *filp, wait_queue_head_t *wait_address, poll_table *_p) +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; @@ -98,7 +109,7 @@ void __pollwait(struct file *filp, wait_queue_head_t *wait_address, poll_table * if (!new_table) { p->error = -ENOMEM; __set_current_state(TASK_RUNNING); - return; + return NULL; } new_table->entry = new_table->entries; new_table->next = table; @@ -106,16 +117,21 @@ void __pollwait(struct file *filp, wait_queue_head_t *wait_address, poll_table * table = new_table; } - /* Add a new entry */ - { - struct poll_table_entry * entry = table->entry; - table->entry = entry+1; - get_file(filp); - entry->filp = filp; - entry->wait_address = wait_address; - init_waitqueue_entry(&entry->wait, current); - add_wait_queue(wait_address,&entry->wait); - } + 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) @@ -129,11 +145,13 @@ 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; - open_fds = current->files->open_fds->fds_bits+n; + fdt = files_fdtable(current->files); + open_fds = fdt->open_fds->fds_bits+n; max = 0; if (set) { set &= BITS(fds, n); @@ -173,16 +191,15 @@ get_max: #define POLLOUT_SET (POLLWRBAND | POLLWRNORM | POLLOUT | POLLERR) #define POLLEX_SET (POLLPRI) -int do_select(int n, fd_set_bits *fds, long *timeout) +int do_select(int n, fd_set_bits *fds, s64 *timeout) { struct poll_wqueues table; poll_table *wait; int retval, i; - long __timeout = *timeout; - spin_lock(¤t->files->file_lock); + rcu_read_lock(); retval = max_select_fd(n, fds); - spin_unlock(¤t->files->file_lock); + rcu_read_unlock(); if (retval < 0) return retval; @@ -190,11 +207,12 @@ int do_select(int n, fd_set_bits *fds, long *timeout) poll_initwait(&table); wait = &table.pt; - if (!__timeout) + if (!*timeout) wait = NULL; retval = 0; for (;;) { unsigned long *rinp, *routp, *rexp, *inp, *outp, *exp; + long __timeout; set_current_state(TASK_INTERRUPTIBLE); @@ -204,7 +222,7 @@ int do_select(int n, fd_set_bits *fds, long *timeout) 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; - struct file_operations *f_op = NULL; + const struct file_operations *f_op = NULL; struct file *file = NULL; in = *inp++; out = *outp++; ex = *exp++; @@ -215,17 +233,18 @@ int do_select(int n, fd_set_bits *fds, long *timeout) } for (j = 0; j < __NFDBITS; ++j, ++i, bit <<= 1) { + int fput_needed; if (i >= n) break; if (!(bit & all_bits)) continue; - file = fget(i); + 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(file); + fput_light(file, fput_needed); if ((mask & POLLIN_SET) && (in & bit)) { res_in |= bit; retval++; @@ -239,6 +258,7 @@ int do_select(int n, fd_set_bits *fds, long *timeout) retval++; } } + cond_resched(); } if (res_in) *rinp = res_in; @@ -248,37 +268,35 @@ int do_select(int n, fd_set_bits *fds, long *timeout) *rexp = res_ex; } wait = NULL; - if (retval || !__timeout || signal_pending(current)) + 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); - /* - * Up-to-date the caller timeout. - */ - *timeout = __timeout; return retval; } -EXPORT_SYMBOL(do_select); - -static void *select_bits_alloc(int size) -{ - return kmalloc(6 * size, GFP_KERNEL); -} - -static void select_bits_free(void *bits, int size) -{ - kfree(bits); -} - /* * We can actually return ERESTARTSYS instead of EINTR, but I'd * like to be certain this leads to no problems. So I return @@ -290,39 +308,26 @@ static void select_bits_free(void *bits, int size) #define MAX_SELECT_SECONDS \ ((unsigned long) (MAX_SCHEDULE_TIMEOUT / HZ)-1) -asmlinkage long -sys_select(int n, fd_set __user *inp, fd_set __user *outp, fd_set __user *exp, struct timeval __user *tvp) +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; - char *bits; - long timeout; - int ret, size, max_fdset; - - timeout = MAX_SCHEDULE_TIMEOUT; - if (tvp) { - time_t sec, usec; - - if ((ret = verify_area(VERIFY_READ, tvp, sizeof(*tvp))) - || (ret = __get_user(sec, &tvp->tv_sec)) - || (ret = __get_user(usec, &tvp->tv_usec))) - goto out_nofds; - - ret = -EINVAL; - if (sec < 0 || usec < 0) - goto out_nofds; - - if ((unsigned long) sec < MAX_SELECT_SECONDS) { - timeout = ROUND_UP(usec, 1000000/HZ); - timeout += sec * (unsigned long) HZ; - } - } + void *bits; + int ret, max_fdset; + 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_fdset can increase, so grab it once to avoid race */ - max_fdset = current->files->max_fdset; + rcu_read_lock(); + fdt = files_fdtable(current->files); + max_fdset = fdt->max_fdset; + rcu_read_unlock(); if (n > max_fdset) n = max_fdset; @@ -331,17 +336,21 @@ sys_select(int n, fd_set __user *inp, fd_set __user *outp, fd_set __user *exp, s * since we used fdset we need to allocate memory in units of * long-words. */ - ret = -ENOMEM; size = FDS_BYTES(n); - bits = select_bits_alloc(size); - 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); + 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)) || @@ -351,18 +360,7 @@ sys_select(int n, fd_set __user *inp, fd_set __user *outp, fd_set __user *exp, s zero_fd_set(n, fds.res_out); zero_fd_set(n, fds.res_ex); - ret = do_select(n, &fds, &timeout); - - if (tvp && !(current->personality & STICKY_TIMEOUTS)) { - time_t sec = 0, usec = 0; - if (timeout) { - sec = timeout / HZ; - usec = timeout % HZ; - usec *= (1000000/HZ); - } - put_user(sec, &tvp->tv_sec); - put_user(usec, &tvp->tv_usec); - } + ret = do_select(n, &fds, timeout); if (ret < 0) goto out; @@ -379,11 +377,169 @@ sys_select(int n, fd_set __user *inp, fd_set __user *outp, fd_set __user *exp, s ret = -EFAULT; out: - select_bits_free(bits, size); + 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 = 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 = 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; @@ -406,14 +562,15 @@ static void do_pollfd(unsigned int num, struct pollfd * fdpage, fdp = fdpage+i; fd = fdp->fd; if (fd >= 0) { - struct file * file = fget(fd); + int fput_needed; + struct 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 &= fdp->events | POLLERR | POLLHUP; - fput(file); + fput_light(file, fput_needed); } if (mask) { *pwait = NULL; @@ -425,16 +582,19 @@ static void do_pollfd(unsigned int num, struct pollfd * fdpage, } static int do_poll(unsigned int nfds, struct poll_list *list, - struct poll_wqueues *wait, long timeout) + struct poll_wqueues *wait, s64 *timeout) { int count = 0; poll_table* pt = &wait->pt; - if (!timeout) + /* Optimise the no-wait case */ + if (!(*timeout)) pt = NULL; for (;;) { struct poll_list *walk; + long __timeout; + set_current_state(TASK_INTERRUPTIBLE); walk = list; while(walk != NULL) { @@ -442,37 +602,61 @@ static int do_poll(unsigned int nfds, struct poll_list *list, walk = walk->next; } pt = NULL; - if (count || !timeout || signal_pending(current)) + if (count || !*timeout || signal_pending(current)) break; count = wait->error; if (count) break; - timeout = schedule_timeout(timeout); + + 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; } -asmlinkage long sys_poll(struct pollfd __user * ufds, unsigned int nfds, long timeout) +#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 fdcount, err; unsigned int i; struct poll_list *head; struct poll_list *walk; + struct fdtable *fdt; + int max_fdset; + /* 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; /* Do a sanity check on nfds ... */ - if (nfds > current->files->max_fdset && nfds > OPEN_MAX) + rcu_read_lock(); + fdt = files_fdtable(current->files); + max_fdset = fdt->max_fdset; + rcu_read_unlock(); + if (nfds > max_fdset && nfds > OPEN_MAX) return -EINVAL; - if (timeout) { - /* Careful about overflow in the intermediate values */ - if ((unsigned long) timeout < MAX_SCHEDULE_TIMEOUT / HZ) - timeout = (unsigned long)(timeout*HZ+999)/1000+1; - else /* Negative or overflow */ - timeout = MAX_SCHEDULE_TIMEOUT; - } - poll_initwait(&table); head = NULL; @@ -481,14 +665,23 @@ asmlinkage long sys_poll(struct pollfd __user * ufds, unsigned int nfds, long ti err = -ENOMEM; while(i!=0) { struct poll_list *pp; - pp = kmalloc(sizeof(struct poll_list)+ - sizeof(struct pollfd)* - (i>POLLFD_PER_PAGE?POLLFD_PER_PAGE:i), - GFP_KERNEL); - if(pp==NULL) - goto out_fds; + 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 = (i>POLLFD_PER_PAGE?POLLFD_PER_PAGE:i); + pp->len = num; if (head == NULL) head = pp; else @@ -496,12 +689,13 @@ asmlinkage long sys_poll(struct pollfd __user * ufds, unsigned int nfds, long ti walk = pp; if (copy_from_user(pp->entries, ufds + nfds-i, - sizeof(struct pollfd)*pp->len)) { + sizeof(struct pollfd)*num)) { err = -EFAULT; goto out_fds; } i -= pp->len; } + fdcount = do_poll(nfds, head, &table, timeout); /* OK, now copy the revents fields back to user space. */ @@ -524,9 +718,110 @@ out_fds: walk = head; while(walk!=NULL) { struct poll_list *pp = walk->next; - kfree(walk); + if (walk != stack_pp) + kfree(walk); walk = pp; } poll_freewait(&table); return err; } + +asmlinkage long sys_poll(struct pollfd __user *ufds, unsigned int nfds, + long timeout_msecs) +{ + s64 timeout_jiffies = 0; + + if (timeout_msecs) { +#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); + } + + 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 = 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 */