Home » Mailing list archives » linux-kernel » 2007 » October » 14

[PATCH] Hook compat_sys_nanosleep up to high res timer code

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Next thread: Which companies are helping developing the kernel by Stefan Heinrichsen on Sunday, October 14, 2007 - 6:06 pm. (6 messages)
[view original message]
From: Anton Blanchard <anton@...>
To: <mingo@...>, <tglx@...>
Cc: <linuxppc-dev@...>, <linux-kernel@...>
Subject: [PATCH] Hook compat_sys_nanosleep up to high res timer code
Date: Sunday, October 14, 2007 - 5:54 pm

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 makes compat_sys_nanosleep call hrtimer_nanosleep

and uses compat_alloc_user_space to avoid setting KERNEL_DS.


Signed-off-by: Anton Blanchard <anton@samba.org>

---


diff --git a/kernel/compat.c b/kernel/compat.c

index 3bae374..46795ac 100644

--- a/kernel/compat.c

+++ b/kernel/compat.c

@@ -40,62 +40,29 @@ 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;

+	struct timespec __user *rmtp64;

+	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(&am...
[ message continues ]
[view original message]
From: Arnd Bergmann <arnd@...>
To: <linuxppc-dev@...>
Cc: Anton Blanchard <anton@...>, <mingo@...>, <tglx@...>, <linux-kernel@...>
Subject: Re: [PATCH] Hook compat_sys_nanosleep up to high res timer code
Date: Sunday, October 14, 2007 - 6:28 pm

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.


This would also make it possible to get rid of set_fs() in

compat_sys_clock_nanosleep().


	Arnd <><

-
[view original message]
From: Anton Blanchard <anton@...>
To: Arnd Bergmann <arnd@...>
Cc: <linuxppc-dev@...>, <mingo@...>, <tglx@...>, <linux-kernel@...>
Subject: Re: [PATCH] Hook compat_sys_nanosleep up to high res timer code
Date: Sunday, October 14, 2007 - 7:16 pm

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 <anton@samba.org>

---


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 ...
[ message continues ]
[view original message]
From: Thomas Gleixner <tglx@...>
To: Anton Blanchard <anton@...>
Cc: Arnd Bergmann <arnd@...>, <linuxppc-dev@...>, <mingo@...>, <linux-kernel@...>
Subject: Re: [PATCH] Hook compat_sys_nanosleep up to high res timer code
Date: Monday, October 15, 2007 - 2:11 am

Thanks,


	tglx

-
[view original message]
From: Anton Blanchard <anton@...>
To: Thomas Gleixner <tglx@...>
Cc: Arnd Bergmann <arnd@...>, <linuxppc-dev@...>, <mingo@...>, <linux-kernel@...>
Subject: [PATCH] Rework hrtimer_nanosleep to make sys_compat_nanosleep easier
Date: Monday, October 15, 2007 - 2:38 am

Hi Thomas,


Thanks for the review, updates to follow.


Anton


--


Pull the copy_to_user out of hrtimer_nanosleep and into the callers

(common_nsleep, sys_nanosleep) in preparation for converting

compat_sys_nanosleep to use hrtimers.


Signed-off-by: Anton Blanchard <anton@samba.org>

---


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/hrtimer.c b/kernel/hrtimer.c

index dc8a445..129fead 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 -ERESTA...
[ message continues ]
[view original message]
From: Arnd Bergmann <arnd@...>
To: <linuxppc-dev@...>
Cc: Anton Blanchard <anton@...>, Thomas Gleixner <tglx@...>, <mingo@...>, <linux-kernel@...>
Subject: Re: [PATCH] Rework hrtimer_nanosleep to make sys_compat_nanosleep easier
Date: Monday, October 15, 2007 - 3:28 am

If it's common to call sys_nanosleep with a NULL rmtp argument, we could save a

few cycles using 


	return hrtimer_nanosleep(&tu, rmtp ? &rmp : NULL, HRTIMER_MODE_REL,


I think it would be better here to propagate the move to a kernel *rmtp

down to sys_clock_nanosleep so we get the same optimization in

compat_sys_clock_nanosleep. That should probably also be a separate

patch. I can do one if you don't do it first.


	Arnd <><

-
[view original message]
From: Anton Blanchard <anton@...>
To: Arnd Bergmann <arnd@...>
Cc: <linuxppc-dev@...>, Thomas Gleixner <tglx@...>, <mingo@...>, <linux-kernel@...>
Subject: [PATCH] Hook compat_sys_nanosleep up to high res timer code
Date: Monday, October 15, 2007 - 5:13 pm

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 follow patch converts compat_sys_nanosleep to use high res timers.


Signed-off-by: Anton Blanchard <anton@samba.org>

---


diff --git a/kernel/compat.c b/kernel/compat.c

index 3bae374..252a446 100644

--- a/kernel/compat.c

+++ b/kernel/compat.c

@@ -40,62 +40,27 @@ 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 (...
[ message continues ]
[view original message]
From: Anton Blanchard <anton@...>
To: Arnd Bergmann <arnd@...>
Cc: <linuxppc-dev@...>, Thomas Gleixner <tglx@...>, <mingo@...>, <linux-kernel@...>
Subject: [PATCH] Rework hrtimer_nanosleep to make sys_compat_nanosleep easier
Date: Monday, October 15, 2007 - 5:06 pm

I can get to this later in the week, if you feel the urge in the

meantime go for it :)


Anton


--


Pull the copy_to_user out of hrtimer_nanosleep and into the callers

(common_nsleep, sys_nanosleep) in preparation for converting

compat_sys_nanosleep to use hrtimers.


Signed-off-by: Anton Blanchard <anton@samba.org>

Acked-by: Arnd Bergmann <arnd@arndb.de>

---


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/hrtimer.c b/kernel/hrtimer.c

index dc8a445..b2b2c2b 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 @@ lon...
[ message continues ]
[view original message]
From: Anton Blanchard <anton@...>
To: Thomas Gleixner <tglx@...>
Cc: Arnd Bergmann <arnd@...>, <linuxppc-dev@...>, <mingo@...>, <linux-kernel@...>
Subject: [PATCH] Hook compat_sys_nanosleep up to high res timer code
Date: Monday, October 15, 2007 - 2:43 am

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 follow patch converts compat_sys_nanosleep to use high res timers.


Signed-off-by: Anton Blanchard <anton@samba.org>

---


diff --git a/kernel/compat.c b/kernel/compat.c

index 3bae374..729f63d 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 ...
[ message continues ]
Previous thread: {GIT pull] x86 bugfixes by Thomas Gleixner on Sunday, October 14, 2007 - 5:29 pm. (3 messages)

Next thread: Which companies are helping developing the kernel by Stefan Heinrichsen on Sunday, October 14, 2007 - 6:06 pm. (6 messages)