Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1764304AbXJNXUj (ORCPT ); Sun, 14 Oct 2007 19:20:39 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1759439AbXJNXUb (ORCPT ); Sun, 14 Oct 2007 19:20:31 -0400 Received: from ozlabs.org ([203.10.76.45]:35223 "EHLO ozlabs.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1759930AbXJNXUb (ORCPT ); Sun, 14 Oct 2007 19:20:31 -0400 Date: Sun, 14 Oct 2007 18:16:16 -0500 From: Anton Blanchard To: Arnd Bergmann Cc: linuxppc-dev@ozlabs.org, mingo@elte.hu, tglx@linutronix.de, linux-kernel@vger.kernel.org Subject: Re: [PATCH] Hook compat_sys_nanosleep up to high res timer code Message-ID: <20071014231616.GA24519@kryten> References: <20071014215437.GF26693@kryten> <200710150028.06493.arnd@arndb.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <200710150028.06493.arnd@arndb.de> User-Agent: Mutt/1.5.15+20070412 (2007-04-11) Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 7226 Lines: 231 Hi Arnd, > The code looks correct, but I think it would be nicer to change > hrtimer_nanosleep to take a kernel pointer and have all three > callers (common_nsleep, sys_nanosleep and compat_sys_nanosleep) > do the copy_to_user/put_compat_timespec in the caller. Good idea, I had considered that but thought a larger cleanup might run afoul of the merge rules :) Regardless, here it is. Id appreciate a once over since it does affect more code than the previous patch :) Anton -- Now we have high res timers on ppc64 I thought Id test them. It turns out compat_sys_nanosleep hasnt been converted to the hrtimer code and so is limited to HZ resolution. The following patch pulls the copy_to_user out of hrtimer_nanosleep and into the callers (common_nsleep, sys_nanosleep and compat_sys_nanosleep) thus avoiding any set_fs(KERNEL_DS) or compat_alloc_userspace tricks. Signed-off-by: Anton Blanchard --- diff --git a/include/linux/hrtimer.h b/include/linux/hrtimer.h index 540799b..7a9398e 100644 --- a/include/linux/hrtimer.h +++ b/include/linux/hrtimer.h @@ -300,7 +300,7 @@ hrtimer_forward(struct hrtimer *timer, ktime_t now, ktime_t interval); /* Precise sleep: */ extern long hrtimer_nanosleep(struct timespec *rqtp, - struct timespec __user *rmtp, + struct timespec *rmtp, const enum hrtimer_mode mode, const clockid_t clockid); extern long hrtimer_nanosleep_restart(struct restart_block *restart_block); diff --git a/kernel/compat.c b/kernel/compat.c index 3bae374..44abfce 100644 --- a/kernel/compat.c +++ b/kernel/compat.c @@ -40,62 +40,26 @@ int put_compat_timespec(const struct timespec *ts, struct compat_timespec __user __put_user(ts->tv_nsec, &cts->tv_nsec)) ? -EFAULT : 0; } -static long compat_nanosleep_restart(struct restart_block *restart) -{ - unsigned long expire = restart->arg0, now = jiffies; - struct compat_timespec __user *rmtp; - - /* Did it expire while we handled signals? */ - if (!time_after(expire, now)) - return 0; - - expire = schedule_timeout_interruptible(expire - now); - if (expire == 0) - return 0; - - rmtp = (struct compat_timespec __user *)restart->arg1; - if (rmtp) { - struct compat_timespec ct; - struct timespec t; - - jiffies_to_timespec(expire, &t); - ct.tv_sec = t.tv_sec; - ct.tv_nsec = t.tv_nsec; - if (copy_to_user(rmtp, &ct, sizeof(ct))) - return -EFAULT; - } - /* The 'restart' block is already filled in */ - return -ERESTART_RESTARTBLOCK; -} - asmlinkage long compat_sys_nanosleep(struct compat_timespec __user *rqtp, - struct compat_timespec __user *rmtp) + struct compat_timespec __user *rmtp) { - struct timespec t; - struct restart_block *restart; - unsigned long expire; + struct timespec tu, rmt; + long ret; - if (get_compat_timespec(&t, rqtp)) + if (get_compat_timespec(&tu, rqtp)) return -EFAULT; - if ((t.tv_nsec >= 1000000000L) || (t.tv_nsec < 0) || (t.tv_sec < 0)) + if (!timespec_valid(&tu)) return -EINVAL; - expire = timespec_to_jiffies(&t) + (t.tv_sec || t.tv_nsec); - expire = schedule_timeout_interruptible(expire); - if (expire == 0) - return 0; + ret = hrtimer_nanosleep(&tu, &rmt, HRTIMER_MODE_REL, CLOCK_MONOTONIC); - if (rmtp) { - jiffies_to_timespec(expire, &t); - if (put_compat_timespec(&t, rmtp)) + if (ret) { + if (put_compat_timespec(&rmt, rmtp)) return -EFAULT; } - restart = ¤t_thread_info()->restart_block; - restart->fn = compat_nanosleep_restart; - restart->arg0 = jiffies + expire; - restart->arg1 = (unsigned long) rmtp; - return -ERESTART_RESTARTBLOCK; + + return ret; } static inline long get_compat_itimerval(struct itimerval *o, diff --git a/kernel/hrtimer.c b/kernel/hrtimer.c index dc8a445..095e09e 100644 --- a/kernel/hrtimer.c +++ b/kernel/hrtimer.c @@ -1286,8 +1286,7 @@ static int __sched do_nanosleep(struct hrtimer_sleeper *t, enum hrtimer_mode mod long __sched hrtimer_nanosleep_restart(struct restart_block *restart) { struct hrtimer_sleeper t; - struct timespec __user *rmtp; - struct timespec tu; + struct timespec *rmtp; ktime_t time; restart->fn = do_no_restart_syscall; @@ -1298,14 +1297,12 @@ long __sched hrtimer_nanosleep_restart(struct restart_block *restart) if (do_nanosleep(&t, HRTIMER_MODE_ABS)) return 0; - rmtp = (struct timespec __user *) restart->arg1; + rmtp = (struct timespec *)restart->arg1; if (rmtp) { time = ktime_sub(t.timer.expires, t.timer.base->get_time()); if (time.tv64 <= 0) return 0; - tu = ktime_to_timespec(time); - if (copy_to_user(rmtp, &tu, sizeof(tu))) - return -EFAULT; + *rmtp = ktime_to_timespec(time); } restart->fn = hrtimer_nanosleep_restart; @@ -1314,12 +1311,11 @@ long __sched hrtimer_nanosleep_restart(struct restart_block *restart) return -ERESTART_RESTARTBLOCK; } -long hrtimer_nanosleep(struct timespec *rqtp, struct timespec __user *rmtp, +long hrtimer_nanosleep(struct timespec *rqtp, struct timespec *rmtp, const enum hrtimer_mode mode, const clockid_t clockid) { struct restart_block *restart; struct hrtimer_sleeper t; - struct timespec tu; ktime_t rem; hrtimer_init(&t.timer, clockid, mode); @@ -1335,9 +1331,7 @@ long hrtimer_nanosleep(struct timespec *rqtp, struct timespec __user *rmtp, rem = ktime_sub(t.timer.expires, t.timer.base->get_time()); if (rem.tv64 <= 0) return 0; - tu = ktime_to_timespec(rem); - if (copy_to_user(rmtp, &tu, sizeof(tu))) - return -EFAULT; + *rmtp = ktime_to_timespec(rem); } restart = ¤t_thread_info()->restart_block; @@ -1353,7 +1347,8 @@ long hrtimer_nanosleep(struct timespec *rqtp, struct timespec __user *rmtp, asmlinkage long sys_nanosleep(struct timespec __user *rqtp, struct timespec __user *rmtp) { - struct timespec tu; + struct timespec tu, rmt; + int ret; if (copy_from_user(&tu, rqtp, sizeof(tu))) return -EFAULT; @@ -1361,7 +1356,14 @@ sys_nanosleep(struct timespec __user *rqtp, struct timespec __user *rmtp) if (!timespec_valid(&tu)) return -EINVAL; - return hrtimer_nanosleep(&tu, rmtp, HRTIMER_MODE_REL, CLOCK_MONOTONIC); + ret = hrtimer_nanosleep(&tu, &rmt, HRTIMER_MODE_REL, CLOCK_MONOTONIC); + + if (ret) { + if (copy_to_user(rmtp, &rmt, sizeof(*rmtp))) + return -EFAULT; + } + + return ret; } /* diff --git a/kernel/posix-timers.c b/kernel/posix-timers.c index 7a15afb..fc7dac2 100644 --- a/kernel/posix-timers.c +++ b/kernel/posix-timers.c @@ -980,9 +980,19 @@ sys_clock_getres(const clockid_t which_clock, struct timespec __user *tp) static int common_nsleep(const clockid_t which_clock, int flags, struct timespec *tsave, struct timespec __user *rmtp) { - return hrtimer_nanosleep(tsave, rmtp, flags & TIMER_ABSTIME ? + struct timespec rmt; + int ret; + + ret = hrtimer_nanosleep(tsave, &rmt, flags & TIMER_ABSTIME ? HRTIMER_MODE_ABS : HRTIMER_MODE_REL, which_clock); + + if (ret) { + if (copy_to_user(rmtp, &rmt, sizeof(*rmtp))) + return -EFAULT; + } + + return ret; } asmlinkage long - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/