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author | Oleg Nesterov <oleg@redhat.com> | 2011-04-27 21:44:14 +0200 |
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committer | Oleg Nesterov <oleg@redhat.com> | 2011-04-28 13:01:38 +0200 |
commit | 943df1485a8ff0e600729e082e568ece04d4de9e (patch) | |
tree | d2d4b7b41f163e011cb7a373376c9ae87e5941be | |
parent | fe0faa005d43bc44c357631d51c273806086caa4 (diff) | |
download | linux-stable-943df1485a8ff0e600729e082e568ece04d4de9e.tar.gz linux-stable-943df1485a8ff0e600729e082e568ece04d4de9e.tar.bz2 linux-stable-943df1485a8ff0e600729e082e568ece04d4de9e.zip |
signal: introduce do_sigtimedwait() to factor out compat/native code
Factor out the common code in sys_rt_sigtimedwait/compat_sys_rt_sigtimedwait
to the new helper, do_sigtimedwait().
Add the comment to document the extra tick we add to timespec_to_jiffies(ts),
thanks to Linus who explained this to me.
Perhaps it would be better to move compat_sys_rt_sigtimedwait() into
signal.c under CONFIG_COMPAT, then we can make do_sigtimedwait() static.
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Tejun Heo <tj@kernel.org>
Reviewed-by: Matt Fleming <matt.fleming@linux.intel.com>
-rw-r--r-- | include/linux/signal.h | 2 | ||||
-rw-r--r-- | kernel/compat.c | 41 | ||||
-rw-r--r-- | kernel/signal.c | 110 |
3 files changed, 74 insertions, 79 deletions
diff --git a/include/linux/signal.h b/include/linux/signal.h index ba009c167275..782546d661ba 100644 --- a/include/linux/signal.h +++ b/include/linux/signal.h @@ -242,6 +242,8 @@ extern int __group_send_sig_info(int, struct siginfo *, struct task_struct *); extern long do_rt_tgsigqueueinfo(pid_t tgid, pid_t pid, int sig, siginfo_t *info); extern long do_sigpending(void __user *, unsigned long); +extern int do_sigtimedwait(const sigset_t *, siginfo_t *, + const struct timespec *); extern int sigprocmask(int, sigset_t *, sigset_t *); extern void set_current_blocked(const sigset_t *); extern int show_unhandled_signals; diff --git a/kernel/compat.c b/kernel/compat.c index 06cbb0619531..9214dcd087b7 100644 --- a/kernel/compat.c +++ b/kernel/compat.c @@ -890,10 +890,9 @@ compat_sys_rt_sigtimedwait (compat_sigset_t __user *uthese, { compat_sigset_t s32; sigset_t s; - int sig; struct timespec t; siginfo_t info; - long ret, timeout; + long ret; if (sigsetsize != sizeof(sigset_t)) return -EINVAL; @@ -901,45 +900,19 @@ compat_sys_rt_sigtimedwait (compat_sigset_t __user *uthese, if (copy_from_user(&s32, uthese, sizeof(compat_sigset_t))) return -EFAULT; sigset_from_compat(&s, &s32); - sigdelsetmask(&s,sigmask(SIGKILL)|sigmask(SIGSTOP)); - signotset(&s); - timeout = MAX_SCHEDULE_TIMEOUT; if (uts) { - if (get_compat_timespec (&t, uts)) + if (get_compat_timespec(&t, uts)) return -EFAULT; - if (!timespec_valid(&t)) - return -EINVAL; - timeout = timespec_to_jiffies(&t) + (t.tv_sec || t.tv_nsec); } - spin_lock_irq(¤t->sighand->siglock); - sig = dequeue_signal(current, &s, &info); - if (!sig && timeout) { - current->real_blocked = current->blocked; - sigandsets(¤t->blocked, ¤t->blocked, &s); - recalc_sigpending(); - spin_unlock_irq(¤t->sighand->siglock); - - timeout = schedule_timeout_interruptible(timeout); - - spin_lock_irq(¤t->sighand->siglock); - sig = dequeue_signal(current, &s, &info); - current->blocked = current->real_blocked; - siginitset(¤t->real_blocked, 0); - recalc_sigpending(); - } - spin_unlock_irq(¤t->sighand->siglock); + ret = do_sigtimedwait(&s, &info, uts ? &t : NULL); - if (sig) { - ret = sig; - if (uinfo) { - if (copy_siginfo_to_user32(uinfo, &info)) - ret = -EFAULT; - } - } else { - ret = timeout?-EINTR:-EAGAIN; + if (ret > 0 && uinfo) { + if (copy_siginfo_to_user32(uinfo, &info)) + ret = -EFAULT; } + return ret; } diff --git a/kernel/signal.c b/kernel/signal.c index c734619554f6..1ab89f677424 100644 --- a/kernel/signal.c +++ b/kernel/signal.c @@ -2504,6 +2504,66 @@ int copy_siginfo_to_user(siginfo_t __user *to, siginfo_t *from) #endif /** + * do_sigtimedwait - wait for queued signals specified in @which + * @which: queued signals to wait for + * @info: if non-null, the signal's siginfo is returned here + * @ts: upper bound on process time suspension + */ +int do_sigtimedwait(const sigset_t *which, siginfo_t *info, + const struct timespec *ts) +{ + struct task_struct *tsk = current; + long timeout = MAX_SCHEDULE_TIMEOUT; + sigset_t mask = *which; + int sig; + + if (ts) { + if (!timespec_valid(ts)) + return -EINVAL; + timeout = timespec_to_jiffies(ts); + /* + * We can be close to the next tick, add another one + * to ensure we will wait at least the time asked for. + */ + if (ts->tv_sec || ts->tv_nsec) + timeout++; + } + + /* + * Invert the set of allowed signals to get those we want to block. + */ + sigdelsetmask(&mask, sigmask(SIGKILL) | sigmask(SIGSTOP)); + signotset(&mask); + + spin_lock_irq(&tsk->sighand->siglock); + sig = dequeue_signal(tsk, &mask, info); + if (!sig && timeout) { + /* + * None ready, temporarily unblock those we're interested + * while we are sleeping in so that we'll be awakened when + * they arrive. + */ + tsk->real_blocked = tsk->blocked; + sigandsets(&tsk->blocked, &tsk->blocked, &mask); + recalc_sigpending(); + spin_unlock_irq(&tsk->sighand->siglock); + + timeout = schedule_timeout_interruptible(timeout); + + spin_lock_irq(&tsk->sighand->siglock); + sig = dequeue_signal(tsk, &mask, info); + tsk->blocked = tsk->real_blocked; + siginitset(&tsk->real_blocked, 0); + recalc_sigpending(); + } + spin_unlock_irq(&tsk->sighand->siglock); + + if (sig) + return sig; + return timeout ? -EINTR : -EAGAIN; +} + +/** * sys_rt_sigtimedwait - synchronously wait for queued signals specified * in @uthese * @uthese: queued signals to wait for @@ -2515,11 +2575,10 @@ SYSCALL_DEFINE4(rt_sigtimedwait, const sigset_t __user *, uthese, siginfo_t __user *, uinfo, const struct timespec __user *, uts, size_t, sigsetsize) { - int ret, sig; sigset_t these; struct timespec ts; siginfo_t info; - long timeout; + int ret; /* XXX: Don't preclude handling different sized sigset_t's. */ if (sigsetsize != sizeof(sigset_t)) @@ -2528,55 +2587,16 @@ SYSCALL_DEFINE4(rt_sigtimedwait, const sigset_t __user *, uthese, if (copy_from_user(&these, uthese, sizeof(these))) return -EFAULT; - /* - * Invert the set of allowed signals to get those we - * want to block. - */ - sigdelsetmask(&these, sigmask(SIGKILL)|sigmask(SIGSTOP)); - signotset(&these); - - timeout = MAX_SCHEDULE_TIMEOUT; if (uts) { if (copy_from_user(&ts, uts, sizeof(ts))) return -EFAULT; - if (!timespec_valid(&ts)) - return -EINVAL; - timeout = timespec_to_jiffies(&ts) + (ts.tv_sec || ts.tv_nsec); } - spin_lock_irq(¤t->sighand->siglock); - sig = dequeue_signal(current, &these, &info); - if (!sig && timeout) { - /* - * None ready -- temporarily unblock those we're - * interested while we are sleeping in so that we'll - * be awakened when they arrive. - */ - current->real_blocked = current->blocked; - sigandsets(¤t->blocked, ¤t->blocked, &these); - recalc_sigpending(); - spin_unlock_irq(¤t->sighand->siglock); - - timeout = schedule_timeout_interruptible(timeout); - - spin_lock_irq(¤t->sighand->siglock); - sig = dequeue_signal(current, &these, &info); - current->blocked = current->real_blocked; - siginitset(¤t->real_blocked, 0); - recalc_sigpending(); - } - spin_unlock_irq(¤t->sighand->siglock); + ret = do_sigtimedwait(&these, &info, uts ? &ts : NULL); - if (sig) { - ret = sig; - if (uinfo) { - if (copy_siginfo_to_user(uinfo, &info)) - ret = -EFAULT; - } - } else { - ret = -EAGAIN; - if (timeout) - ret = -EINTR; + if (ret > 0 && uinfo) { + if (copy_siginfo_to_user(uinfo, &info)) + ret = -EFAULT; } return ret; |