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From: Peter Zijlstra <peterz@infradead.org>
To: Al Viro <viro@ZenIV.linux.org.uk>
Cc: linux-kernel@vger.kernel.org, Thomas Gleixner <tglx@linutronix.de>
Subject: Re: [PATCH 06/16] nanosleep/clock_nanosleep: teach to do compat copyouts
Date: Wed, 7 Jun 2017 12:07:19 +0200	[thread overview]
Message-ID: <20170607100719.tz5sskknvzi2kdyg@hirez.programming.kicks-ass.net> (raw)
In-Reply-To: <20170607084241.28657-6-viro@ZenIV.linux.org.uk>

On Wed, Jun 07, 2017 at 09:42:31AM +0100, Al Viro wrote:
> From: Al Viro <viro@zeniv.linux.org.uk>
> 
> Turn restart_block.nanosleep.{rmtp,compat_rmtp} into a tagged union
> (kind = 1 -> native, kind = 2 -> compat, kind = 0 -> nothing) and
> make the places doing actual copyout handle compat as well as
> native (that will become a helper in the next commit).  Result:
> compat wrappers, messing with reassignments, etc. are gone.

I found something like the below on top slightly easier to read. Ignore
if hated..

---
 include/linux/restart_block.h  | 10 +++++++++-
 kernel/time/alarmtimer.c       |  2 +-
 kernel/time/hrtimer.c          | 23 +++++++++++++++--------
 kernel/time/posix-cpu-timers.c |  2 +-
 kernel/time/posix-stubs.c      |  4 ++--
 kernel/time/posix-timers.c     |  4 ++--
 6 files changed, 30 insertions(+), 15 deletions(-)

diff --git a/include/linux/restart_block.h b/include/linux/restart_block.h
index 4509944bd953..0834e4a8ce69 100644
--- a/include/linux/restart_block.h
+++ b/include/linux/restart_block.h
@@ -11,6 +11,14 @@ struct timespec;
 struct compat_timespec;
 struct pollfd;
 
+enum timespec_type {
+	tt_nothing = 0,
+	tt_native  = 1,
+#ifdef CONFIG_COMPAT
+	tt_compat  = 2,
+#endif
+};
+
 /*
  * System call restart block.
  */
@@ -29,7 +37,7 @@ struct restart_block {
 		/* For nanosleep */
 		struct {
 			clockid_t clockid;
-			int kind;
+			enum timespec_type type;
 			union {
 				struct timespec __user *rmtp;
 #ifdef CONFIG_COMPAT
diff --git a/kernel/time/alarmtimer.c b/kernel/time/alarmtimer.c
index 80154e795535..734920be9d4b 100644
--- a/kernel/time/alarmtimer.c
+++ b/kernel/time/alarmtimer.c
@@ -711,7 +711,7 @@ static int alarmtimer_do_nsleep(struct alarm *alarm, ktime_t absexp,
 	if (freezing(current))
 		alarmtimer_freezerset(absexp, type);
 	restart = &current->restart_block;
-	if (restart->nanosleep.kind) {
+	if (restart->nanosleep.type) {
 		struct timespec rmt;
 		ktime_t rem;
 
diff --git a/kernel/time/hrtimer.c b/kernel/time/hrtimer.c
index 5dd4b3a34495..e1e06a8b6c43 100644
--- a/kernel/time/hrtimer.c
+++ b/kernel/time/hrtimer.c
@@ -1442,15 +1442,22 @@ EXPORT_SYMBOL_GPL(hrtimer_init_sleeper);
 
 int nanosleep_copyout(struct restart_block *restart, struct timespec *ts)
 {
-	BUG_ON(!restart->nanosleep.kind);
+	switch(restart->nanosleep.type) {
 #ifdef CONFIG_COMPAT
-	if (restart->nanosleep.kind == 2) {
+	case tt_compat:
 		if (compat_put_timespec(ts, restart->nanosleep.compat_rmtp))
 			return -EFAULT;
-	} else
+		break;
 #endif
-	if (copy_to_user(restart->nanosleep.rmtp, ts, sizeof(struct timespec)))
-		return -EFAULT;
+	case tt_native:
+		if (copy_to_user(restart->nanosleep.rmtp, ts, sizeof(struct timespec)))
+			return -EFAULT;
+		break;
+
+	case tt_nothing:
+		BUG();
+	}
+
 	return -ERESTART_RESTARTBLOCK;
 }
 
@@ -1477,7 +1484,7 @@ static int __sched do_nanosleep(struct hrtimer_sleeper *t, enum hrtimer_mode mod
 		return 0;
 
 	restart = &current->restart_block;
-	if (restart->nanosleep.kind) {
+	if (restart->nanosleep.type) {
 		struct timespec rmt;
 		ktime_t rem = hrtimer_expires_remaining(&t->timer);
 		if (rem <= 0)
@@ -1549,7 +1556,7 @@ SYSCALL_DEFINE2(nanosleep, struct timespec __user *, rqtp,
 	if (!timespec64_valid(&tu64))
 		return -EINVAL;
 
-	current->restart_block.nanosleep.kind = rmtp ? 1 : 0;
+	current->restart_block.nanosleep.type = rmtp ? tt_native : tt_nothing;
 	current->restart_block.nanosleep.rmtp = rmtp;
 	return hrtimer_nanosleep(&tu64, HRTIMER_MODE_REL, CLOCK_MONOTONIC);
 }
@@ -1569,7 +1576,7 @@ COMPAT_SYSCALL_DEFINE2(nanosleep, struct compat_timespec __user *, rqtp,
 	if (!timespec64_valid(&tu64))
 		return -EINVAL;
 
-	current->restart_block.nanosleep.kind = rmtp ? 2 : 0;
+	current->restart_block.nanosleep.type = rmtp ? tt_compat : tt_nothing;
 	current->restart_block.nanosleep.compat_rmtp = rmtp;
 	return hrtimer_nanosleep(&tu64, HRTIMER_MODE_REL, CLOCK_MONOTONIC);
 }
diff --git a/kernel/time/posix-cpu-timers.c b/kernel/time/posix-cpu-timers.c
index f6c5f77b944d..929499e6b4ac 100644
--- a/kernel/time/posix-cpu-timers.c
+++ b/kernel/time/posix-cpu-timers.c
@@ -1313,7 +1313,7 @@ static int do_cpu_nanosleep(const clockid_t which_clock, int flags,
 		 */
 		restart = &current->restart_block;
 		restart->nanosleep.expires = timespec64_to_ns(rqtp);
-		if (restart->nanosleep.kind) {
+		if (restart->nanosleep.type) {
 			struct timespec ts;
 			ts = timespec64_to_timespec(it.it_value);
 			error = nanosleep_copyout(restart, &ts);
diff --git a/kernel/time/posix-stubs.c b/kernel/time/posix-stubs.c
index c0c18701a4da..4b54dcf8d517 100644
--- a/kernel/time/posix-stubs.c
+++ b/kernel/time/posix-stubs.c
@@ -125,7 +125,7 @@ SYSCALL_DEFINE4(clock_nanosleep, const clockid_t, which_clock, int, flags,
 			return -EINVAL;
 		if (flags & TIMER_ABSTIME)
 			rmtp = NULL;
-		current->restart_block.nanosleep.kind = rmtp ? 1 : 0;
+		current->restart_block.nanosleep.type = rmtp ? tt_native : tt_nothing;
 		current->restart_block.nanosleep.rmtp = rmtp;
 		return hrtimer_nanosleep(&t64, flags & TIMER_ABSTIME ?
 					 HRTIMER_MODE_ABS : HRTIMER_MODE_REL,
@@ -206,7 +206,7 @@ COMPAT_SYSCALL_DEFINE4(clock_nanosleep, clockid_t, which_clock, int, flags,
 			return -EINVAL;
 		if (flags & TIMER_ABSTIME)
 			rmtp = NULL;
-		current->restart_block.nanosleep.kind = rmtp ? 2 : 0;
+		current->restart_block.nanosleep.type = rmtp ? tt_compat : tt_nothing;
 		current->restart_block.nanosleep.compat_rmtp = rmtp;
 		return hrtimer_nanosleep(&t64, flags & TIMER_ABSTIME ?
 					 HRTIMER_MODE_ABS : HRTIMER_MODE_REL,
diff --git a/kernel/time/posix-timers.c b/kernel/time/posix-timers.c
index 014e6ff8982e..3c85d6762690 100644
--- a/kernel/time/posix-timers.c
+++ b/kernel/time/posix-timers.c
@@ -1228,7 +1228,7 @@ SYSCALL_DEFINE4(clock_nanosleep, const clockid_t, which_clock, int, flags,
 		return -EINVAL;
 	if (flags & TIMER_ABSTIME)
 		rmtp = NULL;
-	current->restart_block.nanosleep.kind = rmtp ? 1 : 0;
+	current->restart_block.nanosleep.type = rmtp ? tt_native : tt_nothing;
 	current->restart_block.nanosleep.rmtp = rmtp;
 
 	return kc->nsleep(which_clock, flags, &t64);
@@ -1256,7 +1256,7 @@ COMPAT_SYSCALL_DEFINE4(clock_nanosleep, clockid_t, which_clock, int, flags,
 		return -EINVAL;
 	if (flags & TIMER_ABSTIME)
 		rmtp = NULL;
-	current->restart_block.nanosleep.kind = rmtp ? 2 : 0;
+	current->restart_block.nanosleep.type = rmtp ? tt_compat : tt_nothing;
 	current->restart_block.nanosleep.compat_rmtp = rmtp;
 
 	return kc->nsleep(which_clock, flags, &t64);

  reply	other threads:[~2017-06-07 10:07 UTC|newest]

Thread overview: 36+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2017-06-07  8:41 [PATCHSET] sanitizing compat nanosleep and other timer-related syscalls Al Viro
2017-06-07  8:42 ` [PATCH 01/16] move copyout of timespec into do_cpu_nanosleep() Al Viro
2017-06-07  8:42   ` [PATCH 02/16] move copyout and freeze handling into alarmtimer_do_nsleep() Al Viro
2017-06-13 22:04     ` [tip:timers/core] alarmtimer: Move " tip-bot for Al Viro
2017-06-07  8:42   ` [PATCH 03/16] hrtimer_nanosleep(): pass rmtp in restart_block Al Viro
2017-06-13 22:05     ` [tip:timers/core] hrtimer_nanosleep(): Pass " tip-bot for Al Viro
2017-06-07  8:42   ` [PATCH 04/16] move copyout to do_nanosleel() Al Viro
2017-06-13 22:05     ` [tip:timers/core] hrtimer: Move copyout of remaining time to do_nanosleep() tip-bot for Al Viro
2017-06-07  8:42   ` [PATCH 05/16] clock_nanosleep(): stash rmtp into restart_block Al Viro
2017-06-13 22:06     ` [tip:timers/core] posix-timers: Store rmtp into restart_block in sys_clock_nanosleep() tip-bot for Al Viro
2017-06-07  8:42   ` [PATCH 06/16] nanosleep/clock_nanosleep: teach to do compat copyouts Al Viro
2017-06-07 10:07     ` Peter Zijlstra [this message]
2017-06-13 22:06     ` [tip:timers/core] time/posix-timers: Move the compat copyouts to the nanosleep implementations tip-bot for Al Viro
2017-06-07  8:42   ` [PATCH 07/16] {clock_,}nanosleep(2): merge timespec copyout logics into a new helper Al Viro
2017-06-13 22:07     ` [tip:timers/core] hrtimers/posix-timers: Merge nanosleep " tip-bot for Al Viro
2017-06-07  8:42   ` [PATCH 08/16] kill ->nsleep_restart() Al Viro
2017-06-13 22:08     ` [tip:timers/core] posix-timers: Kill ->nsleep_restart() tip-bot for Al Viro
2017-06-07  8:42   ` [PATCH 09/16] move adjtimex-related compat syscalls to native counterparts Al Viro
2017-06-13 22:08     ` [tip:timers/core] ntp: Move adjtimex related " tip-bot for Al Viro
2017-06-07  8:42   ` [PATCH 10/16] take compat timer_settime(2) to native one Al Viro
2017-06-13 22:09     ` [tip:timers/core] posix-timers: Take " tip-bot for Al Viro
2017-06-07  8:42   ` [PATCH 11/16] take compat timer_gettime(2) " Al Viro
2017-06-13 22:09     ` [tip:timers/core] posix-timers: Take " tip-bot for Al Viro
2017-06-07  8:42   ` [PATCH 12/16] move compat itimer syscalls to native ones Al Viro
2017-06-13 22:10     ` [tip:timers/core] itimers: Move " tip-bot for Al Viro
2017-06-07  8:42   ` [PATCH 13/16] clock_gettime/clock_settime/clock_getres: move to native syscalls Al Viro
2017-06-13 22:10     ` [tip:timers/core] posix-timers: Move compat versions of clock_gettime/settime/getres tip-bot for Al Viro
2017-06-07  8:42   ` [PATCH 14/16] timer_create(): move compat to native, get rid of set_fs() Al Viro
2017-06-13 22:11     ` [tip:timers/core] posix-timers: Move compat_timer_create() " tip-bot for Al Viro
2017-06-07  8:42   ` [PATCH 15/16] time()/stime(): move compat to native Al Viro
2017-06-13 22:11     ` [tip:timers/core] time: Move compat_time()/stime() " tip-bot for Al Viro
2017-06-07  8:42   ` [PATCH 16/16] gettimeofday()/settimeofday(): move compat " Al Viro
2017-06-13 22:12     ` [tip:timers/core] time: Move compat_gettimeofday()/settimeofday() " tip-bot for Al Viro
2017-06-12 23:08   ` [PATCH 01/16] move copyout of timespec into do_cpu_nanosleep() Thomas Gleixner
2017-06-13  7:46     ` Thomas Gleixner
2017-06-13 22:04   ` [tip:timers/core] posix-cpu-timers: Move " tip-bot for Al Viro

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