[PATCH] [1/6] Add pselect/ppoll system call implementation

From: David Woodhouse
Date: Tue Jan 10 2006 - 15:17:08 EST

This patch adds the pselect() and ppoll() system calls, providing core
routines usable by the original select() and poll() system calls and
also the new calls (with their semantics w.r.t timeouts).

Signed-off-by: David Woodhouse <dwmw2@xxxxxxxxxxxxx>

fs/compat.c | 252 +++++++++++++++++++++++++++++++------
fs/select.c | 337 +++++++++++++++++++++++++++++++++++++++++---------
include/linux/poll.h | 6
include/linux/sched.h | 1
4 files changed, 501 insertions(+), 95 deletions(-)

diff --git a/fs/compat.c b/fs/compat.c
index 271b75d..e18a7e6 100644
--- a/fs/compat.c
+++ b/fs/compat.c
@@ -53,6 +53,8 @@
#include <asm/mmu_context.h>
#include <asm/ioctls.h>

+extern void sigset_from_compat(sigset_t *set, compat_sigset_t *compat);
+
/*
* Not all architectures have sys_utime, so implement this in terms
* of sys_utimes.
@@ -1621,36 +1623,14 @@ static void select_bits_free(void *bits,
#define MAX_SELECT_SECONDS \
((unsigned long) (MAX_SCHEDULE_TIMEOUT / HZ)-1)

-asmlinkage long
-compat_sys_select(int n, compat_ulong_t __user *inp, compat_ulong_t __user *outp,
- compat_ulong_t __user *exp, struct compat_timeval __user *tvp)
+int compat_core_sys_select(int n, compat_ulong_t __user *inp,
+ compat_ulong_t __user *outp, compat_ulong_t __user *exp, int64_t *timeout)
{
fd_set_bits fds;
char *bits;
- long timeout;
int size, max_fdset, ret = -EINVAL;
struct fdtable *fdt;

- timeout = MAX_SCHEDULE_TIMEOUT;
- if (tvp) {
- time_t sec, usec;
-
- if (!access_ok(VERIFY_READ, tvp, sizeof(*tvp))
- || __get_user(sec, &tvp->tv_sec)
- || __get_user(usec, &tvp->tv_usec)) {
- ret = -EFAULT;
- goto out_nofds;
- }
-
- 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;
- }
- }
-
if (n < 0)
goto out_nofds;

@@ -1687,19 +1667,7 @@ compat_sys_select(int n, compat_ulong_t
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);
- }
- if (put_user(sec, &tvp->tv_sec) ||
- put_user(usec, &tvp->tv_usec))
- ret = -EFAULT;
- }
+ ret = do_select(n, &fds, timeout);

if (ret < 0)
goto out;
@@ -1720,6 +1688,216 @@ out_nofds:
return ret;
}

+asmlinkage long compat_sys_select(int n, compat_ulong_t __user *inp,
+ compat_ulong_t __user *outp, compat_ulong_t __user *exp,
+ struct compat_timeval __user *tvp)
+{
+ int64_t timeout = -1;
+ struct compat_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 uint64_t to make GCC stop complaining */
+ if ((uint64_t)tv.tv_sec >= (uint64_t)MAX_INT64_SECONDS)
+ timeout = -1; /* infinite */
+ else {
+ timeout = ROUND_UP(tv.tv_sec, 1000000/HZ);
+ timeout += tv.tv_sec * HZ;
+ }
+ }
+
+ ret = compat_core_sys_select(n, inp, outp, exp, &timeout);
+
+ if (tvp) {
+ if (current->personality & STICKY_TIMEOUTS)
+ goto sticky;
+ tv.tv_usec = jiffies_to_usecs(do_div((*(uint64_t*)&timeout), HZ));
+ tv.tv_sec = timeout;
+ if (copy_to_user(tvp, &tv, sizeof(tv))) {
+ 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 compat_sys_pselect7(int n, compat_ulong_t __user *inp,
+ compat_ulong_t __user *outp, compat_ulong_t __user *exp,
+ struct compat_timespec __user *tsp, compat_sigset_t __user *sigmask,
+ compat_size_t sigsetsize)
+{
+ compat_sigset_t s32;
+ sigset_t ksigmask, sigsaved;
+ long timeout = MAX_SCHEDULE_TIMEOUT;
+ struct compat_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;
+ }
+
+ if (sigmask) {
+ if (sigsetsize != sizeof(compat_sigset_t))
+ return -EINVAL;
+ if (copy_from_user(&s32, sigmask, sizeof(s32)))
+ return -EFAULT;
+ sigset_from_compat(&ksigmask, &s32);
+
+ sigdelsetmask(&ksigmask, sigmask(SIGKILL)|sigmask(SIGSTOP));
+ sigprocmask(SIG_SETMASK, &ksigmask, &sigsaved);
+ }
+
+ do {
+ if (tsp) {
+ if ((unsigned long)ts.tv_sec < MAX_SELECT_SECONDS) {
+ timeout = ROUND_UP(ts.tv_nsec, 1000000000/HZ);
+ timeout += ts.tv_sec * (unsigned long)HZ;
+ ts.tv_sec = 0;
+ ts.tv_nsec = 0;
+ } else {
+ ts.tv_sec -= MAX_SELECT_SECONDS;
+ timeout = MAX_SELECT_SECONDS * HZ;
+ }
+ }
+
+ ret = compat_core_sys_select(n, inp, outp, exp, &timeout);
+
+ } while (!ret && !timeout && tsp && (ts.tv_sec || ts.tv_nsec));
+
+ if (tsp && !(current->personality & STICKY_TIMEOUTS)) {
+ ts.tv_sec += timeout / HZ;
+ ts.tv_nsec += (timeout % HZ) * (1000000000/HZ);
+ if (ts.tv_nsec >= 1000000000) {
+ ts.tv_sec++;
+ ts.tv_nsec -= 1000000000;
+ }
+ (void)copy_to_user(tsp, &ts, sizeof(ts));
+ }
+
+ 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(&current->saved_sigmask, &sigsaved, sizeof(sigsaved));
+ set_thread_flag(TIF_RESTORE_SIGMASK);
+ }
+ } else if (sigmask)
+ sigprocmask(SIG_SETMASK, &sigsaved, NULL);
+
+ return ret;
+}
+
+asmlinkage long compat_sys_pselect6(int n, compat_ulong_t __user *inp,
+ compat_ulong_t __user *outp, compat_ulong_t __user *exp,
+ struct compat_timespec __user *tsp, void __user *sig)
+{
+ compat_size_t sigsetsize = 0;
+ compat_uptr_t up = 0;
+
+ if (sig) {
+ if (!access_ok(VERIFY_READ, sig,
+ sizeof(compat_uptr_t)+sizeof(compat_size_t)) ||
+ __get_user(up, (compat_uptr_t __user *)sig) ||
+ __get_user(sigsetsize,
+ (compat_size_t __user *)(sig+sizeof(up))))
+ return -EFAULT;
+ }
+ return compat_sys_pselect7(n, inp, outp, exp, tsp, compat_ptr(up),
+ sigsetsize);
+}
+
+asmlinkage long compat_sys_ppoll(struct pollfd __user *ufds,
+ unsigned int nfds, struct compat_timespec __user *tsp,
+ const compat_sigset_t __user *sigmask, compat_size_t sigsetsize)
+{
+ compat_sigset_t s32;
+ sigset_t ksigmask, sigsaved;
+ struct compat_timespec ts;
+ int64_t timeout = -1;
+ int ret;
+
+ if (tsp) {
+ if (copy_from_user(&ts, tsp, sizeof(ts)))
+ return -EFAULT;
+
+ /* We assume that ts.tv_sec is always lower than
+ the number of seconds that can be expressed in
+ an int64_t. Otherwise the compiler bitches at us */
+ timeout = ROUND_UP(ts.tv_sec, 1000000000/HZ);
+ timeout += ts.tv_sec * HZ;
+ }
+
+ if (sigmask) {
+ if (sigsetsize |= sizeof(compat_sigset_t))
+ return -EINVAL;
+ if (copy_from_user(&s32, sigmask, sizeof(s32)))
+ return -EFAULT;
+ sigset_from_compat(&ksigmask, &s32);
+
+ 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(&current->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) {
+ if (current->personality & STICKY_TIMEOUTS)
+ goto sticky;
+ /* Yes, we know it's actually an int64_t, but it's also positive. */
+ ts.tv_nsec = jiffies_to_usecs(do_div((*(uint64_t*)&timeout), HZ)) * 1000;
+ ts.tv_sec = timeout;
+ if (copy_to_user(tsp, &ts, sizeof(ts))) {
+ 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 */
+
#if defined(CONFIG_NFSD) || defined(CONFIG_NFSD_MODULE)
/* Stuff for NFS server syscalls... */
struct compat_nfsctl_svc {
diff --git a/fs/select.c b/fs/select.c
index f10a103..4e0da96 100644
--- a/fs/select.c
+++ b/fs/select.c
@@ -179,12 +179,11 @@ 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, int64_t *timeout)
{
struct poll_wqueues table;
poll_table *wait;
int retval, i;
- long __timeout = *timeout;

rcu_read_lock();
retval = max_select_fd(n, fds);
@@ -196,11 +195,12 @@ int do_select(int n, fd_set_bits *fds, l

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);

@@ -255,22 +255,32 @@ int do_select(int n, fd_set_bits *fds, l
*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 >= (int64_t)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;
}

@@ -295,36 +305,14 @@ static void select_bits_free(void *bits,
#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, int64_t *timeout)
{
fd_set_bits fds;
char *bits;
- long timeout;
int ret, size, max_fdset;
struct fdtable *fdt;

- timeout = MAX_SCHEDULE_TIMEOUT;
- if (tvp) {
- time_t sec, usec;
-
- if (!access_ok(VERIFY_READ, tvp, sizeof(*tvp))
- || __get_user(sec, &tvp->tv_sec)
- || __get_user(usec, &tvp->tv_usec)) {
- ret = -EFAULT;
- 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;
- }
- }
-
ret = -EINVAL;
if (n < 0)
goto out_nofds;
@@ -362,18 +350,7 @@ sys_select(int n, fd_set __user *inp, fd
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;
@@ -395,6 +372,150 @@ 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)
+{
+ int64_t 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 uint64_t to make GCC stop complaining */
+ if ((uint64_t)tv.tv_sec >= (uint64_t)MAX_INT64_SECONDS)
+ timeout = -1; /* infinite */
+ else {
+ timeout = ROUND_UP(tv.tv_sec, 1000000/HZ);
+ timeout += tv.tv_sec * HZ;
+ }
+ }
+
+ ret = core_sys_select(n, inp, outp, exp, &timeout);
+
+ if (tvp) {
+ if (current->personality & STICKY_TIMEOUTS)
+ goto sticky;
+ tv.tv_usec = jiffies_to_usecs(do_div((*(uint64_t*)&timeout), HZ));
+ tv.tv_sec = timeout;
+ if (copy_to_user(tvp, &tv, sizeof(tv))) {
+ 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)
+{
+ int64_t 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 uint64_t to make GCC stop complaining */
+ if ((uint64_t)ts.tv_sec >= (uint64_t)MAX_INT64_SECONDS)
+ timeout = -1; /* infinite */
+ else {
+ timeout = ROUND_UP(ts.tv_sec, 1000000000/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) {
+ if (current->personality & STICKY_TIMEOUTS)
+ goto sticky;
+ ts.tv_nsec = jiffies_to_usecs(do_div((*(uint64_t*)&timeout), HZ)) * 1000;
+ ts.tv_sec = timeout;
+ if (copy_to_user(tsp, &ts, sizeof(ts))) {
+ 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(&current->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 *)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;
@@ -436,16 +557,19 @@ static void do_pollfd(unsigned int num,
}

static int do_poll(unsigned int nfds, struct poll_list *list,
- struct poll_wqueues *wait, long timeout)
+ struct poll_wqueues *wait, int64_t *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) {
@@ -453,18 +577,33 @@ static int do_poll(unsigned int nfds, s
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 >= (int64_t)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)
+int do_sys_poll(struct pollfd __user *ufds, unsigned int nfds, int64_t *timeout)
{
struct poll_wqueues table;
int fdcount, err;
@@ -482,14 +621,6 @@ asmlinkage long sys_poll(struct pollfd _
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;
@@ -519,6 +650,7 @@ asmlinkage long sys_poll(struct pollfd _
}
i -= pp->len;
}
+
fdcount = do_poll(nfds, head, &table, timeout);

/* OK, now copy the revents fields back to user space. */
@@ -547,3 +679,94 @@ out_fds:
poll_freewait(&table);
return err;
}
+
+asmlinkage long sys_poll(struct pollfd __user *ufds, unsigned int nfds,
+ long timeout_msecs)
+{
+ int64_t timeout_jiffies = 0;
+
+ if (timeout_msecs) {
+#if HZ > 1000
+ /* We can only overflow if HZ > 1000 */
+ if (timeout_msecs / 1000 > (int64_t)0x7fffffffffffffffULL / (int64_t)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;
+ int64_t timeout = -1;
+ int ret;
+
+ if (tsp) {
+ if (copy_from_user(&ts, tsp, sizeof(ts)))
+ return -EFAULT;
+
+ /* Cast to uint64_t to make GCC stop complaining */
+ if ((uint64_t)ts.tv_sec >= (uint64_t)MAX_INT64_SECONDS)
+ timeout = -1; /* infinite */
+ else {
+ timeout = ROUND_UP(ts.tv_sec, 1000000000/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(&current->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) {
+ if (current->personality & STICKY_TIMEOUTS)
+ goto sticky;
+ /* Yes, we know it's actually an int64_t, but it's also positive. */
+ ts.tv_nsec = jiffies_to_usecs(do_div((*(uint64_t*)&timeout), HZ)) * 1000;
+ ts.tv_sec = timeout;
+ if (copy_to_user(tsp, &ts, sizeof(ts))) {
+ 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 */
diff --git a/include/linux/poll.h b/include/linux/poll.h
index f6da702..5b9c85c 100644
--- a/include/linux/poll.h
+++ b/include/linux/poll.h
@@ -92,7 +92,11 @@ void zero_fd_set(unsigned long nr, unsig
memset(fdset, 0, FDS_BYTES(nr));
}

-extern int do_select(int n, fd_set_bits *fds, long *timeout);
+#define MAX_INT64_SECONDS (((int64_t)(~((uint64_t)0)>>1)/HZ)-1)
+
+extern int do_select(int n, fd_set_bits *fds, int64_t *timeout);
+extern int do_sys_poll(struct pollfd __user * ufds, unsigned int nfds,
+ int64_t *timeout);

#endif /* KERNEL */

diff --git a/include/linux/sched.h b/include/linux/sched.h
index c4ee35d..1be70cf 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -798,6 +798,7 @@ struct task_struct {
struct sighand_struct *sighand;

sigset_t blocked, real_blocked;
+ sigset_t saved_sigmask; /* To be restored with TIF_RESTORE_SIGMASK */
struct sigpending pending;

unsigned long sas_ss_sp;

--
dwmw2

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