* [PATCH 1/2 v2] futex: adjust a futex timeout with a per-timens offset
@ 2020-10-15 16:00 Andrei Vagin
2020-10-15 16:02 ` Dmitry Safonov
2020-10-20 15:11 ` [tip: timers/urgent] futex: Adjust absolute futex timeouts with per time namespace offset tip-bot2 for Andrei Vagin
0 siblings, 2 replies; 3+ messages in thread
From: Andrei Vagin @ 2020-10-15 16:00 UTC (permalink / raw)
To: Thomas Gleixner, linux-kernel
Cc: Ingo Molnar, Peter Zijlstra, Darren Hart, Dmitry Safonov,
Shuah Khan, Andrei Vagin, stable
For all commands except FUTEX_WAIT, timeout is interpreted as an
absolute value. This absolute value is inside the task's time namespace
and has to be converted to the host's time.
Cc: <stable@vger.kernel.org>
Fixes: 5a590f35add9 ("posix-clocks: Wire up clock_gettime() with timens offsets")
Reported-by: Hans van der Laan <j.h.vanderlaan@student.utwente.nl>
Signed-off-by: Andrei Vagin <avagin@gmail.com>
---
v2:
* check FUTEX_CLOCK_REALTIME properly
* fix futex_time32 too
kernel/futex.c | 5 +++++
1 file changed, 5 insertions(+)
diff --git a/kernel/futex.c b/kernel/futex.c
index a5876694a60e..32056d2d4171 100644
--- a/kernel/futex.c
+++ b/kernel/futex.c
@@ -39,6 +39,7 @@
#include <linux/freezer.h>
#include <linux/memblock.h>
#include <linux/fault-inject.h>
+#include <linux/time_namespace.h>
#include <asm/futex.h>
@@ -3797,6 +3798,8 @@ SYSCALL_DEFINE6(futex, u32 __user *, uaddr, int, op, u32, val,
t = timespec64_to_ktime(ts);
if (cmd == FUTEX_WAIT)
t = ktime_add_safe(ktime_get(), t);
+ else if (!(op & FUTEX_CLOCK_REALTIME))
+ t = timens_ktime_to_host(CLOCK_MONOTONIC, t);
tp = &t;
}
/*
@@ -3989,6 +3992,8 @@ SYSCALL_DEFINE6(futex_time32, u32 __user *, uaddr, int, op, u32, val,
t = timespec64_to_ktime(ts);
if (cmd == FUTEX_WAIT)
t = ktime_add_safe(ktime_get(), t);
+ else if (!(op & FUTEX_CLOCK_REALTIME))
+ t = timens_ktime_to_host(CLOCK_MONOTONIC, t);
tp = &t;
}
if (cmd == FUTEX_REQUEUE || cmd == FUTEX_CMP_REQUEUE ||
--
2.26.2
^ permalink raw reply related [flat|nested] 3+ messages in thread
* Re: [PATCH 1/2 v2] futex: adjust a futex timeout with a per-timens offset
2020-10-15 16:00 [PATCH 1/2 v2] futex: adjust a futex timeout with a per-timens offset Andrei Vagin
@ 2020-10-15 16:02 ` Dmitry Safonov
2020-10-20 15:11 ` [tip: timers/urgent] futex: Adjust absolute futex timeouts with per time namespace offset tip-bot2 for Andrei Vagin
1 sibling, 0 replies; 3+ messages in thread
From: Dmitry Safonov @ 2020-10-15 16:02 UTC (permalink / raw)
To: Andrei Vagin, Thomas Gleixner, linux-kernel
Cc: Ingo Molnar, Peter Zijlstra, Darren Hart, Shuah Khan, stable
On 10/15/20 5:00 PM, Andrei Vagin wrote:
> For all commands except FUTEX_WAIT, timeout is interpreted as an
> absolute value. This absolute value is inside the task's time namespace
> and has to be converted to the host's time.
>
> Cc: <stable@vger.kernel.org>
> Fixes: 5a590f35add9 ("posix-clocks: Wire up clock_gettime() with timens offsets")
> Reported-by: Hans van der Laan <j.h.vanderlaan@student.utwente.nl>
> Signed-off-by: Andrei Vagin <avagin@gmail.com>
Reviewed-by: Dmitry Safonov <0x7f454c46@gmail.com>
> ---
>
> v2:
> * check FUTEX_CLOCK_REALTIME properly
> * fix futex_time32 too
>
> kernel/futex.c | 5 +++++
> 1 file changed, 5 insertions(+)
>
> diff --git a/kernel/futex.c b/kernel/futex.c
> index a5876694a60e..32056d2d4171 100644
> --- a/kernel/futex.c
> +++ b/kernel/futex.c
> @@ -39,6 +39,7 @@
> #include <linux/freezer.h>
> #include <linux/memblock.h>
> #include <linux/fault-inject.h>
> +#include <linux/time_namespace.h>
>
> #include <asm/futex.h>
>
> @@ -3797,6 +3798,8 @@ SYSCALL_DEFINE6(futex, u32 __user *, uaddr, int, op, u32, val,
> t = timespec64_to_ktime(ts);
> if (cmd == FUTEX_WAIT)
> t = ktime_add_safe(ktime_get(), t);
> + else if (!(op & FUTEX_CLOCK_REALTIME))
> + t = timens_ktime_to_host(CLOCK_MONOTONIC, t);
> tp = &t;
> }
> /*
> @@ -3989,6 +3992,8 @@ SYSCALL_DEFINE6(futex_time32, u32 __user *, uaddr, int, op, u32, val,
> t = timespec64_to_ktime(ts);
> if (cmd == FUTEX_WAIT)
> t = ktime_add_safe(ktime_get(), t);
> + else if (!(op & FUTEX_CLOCK_REALTIME))
> + t = timens_ktime_to_host(CLOCK_MONOTONIC, t);
> tp = &t;
> }
> if (cmd == FUTEX_REQUEUE || cmd == FUTEX_CMP_REQUEUE ||
>
Thanks,
Dmitry
^ permalink raw reply [flat|nested] 3+ messages in thread
* [tip: timers/urgent] futex: Adjust absolute futex timeouts with per time namespace offset
2020-10-15 16:00 [PATCH 1/2 v2] futex: adjust a futex timeout with a per-timens offset Andrei Vagin
2020-10-15 16:02 ` Dmitry Safonov
@ 2020-10-20 15:11 ` tip-bot2 for Andrei Vagin
1 sibling, 0 replies; 3+ messages in thread
From: tip-bot2 for Andrei Vagin @ 2020-10-20 15:11 UTC (permalink / raw)
To: linux-tip-commits
Cc: Hans van der Laan, Andrei Vagin, Thomas Gleixner, Dmitry Safonov,
stable, x86, LKML
The following commit has been merged into the timers/urgent branch of tip:
Commit-ID: c2f7d08cccf4af2ce6992feaabb9e68e4ae0bff3
Gitweb: https://git.kernel.org/tip/c2f7d08cccf4af2ce6992feaabb9e68e4ae0bff3
Author: Andrei Vagin <avagin@gmail.com>
AuthorDate: Thu, 15 Oct 2020 09:00:19 -07:00
Committer: Thomas Gleixner <tglx@linutronix.de>
CommitterDate: Tue, 20 Oct 2020 17:02:57 +02:00
futex: Adjust absolute futex timeouts with per time namespace offset
For all commands except FUTEX_WAIT, the timeout is interpreted as an
absolute value. This absolute value is inside the task's time namespace and
has to be converted to the host's time.
Fixes: 5a590f35add9 ("posix-clocks: Wire up clock_gettime() with timens offsets")
Reported-by: Hans van der Laan <j.h.vanderlaan@student.utwente.nl>
Signed-off-by: Andrei Vagin <avagin@gmail.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Dmitry Safonov <0x7f454c46@gmail.com>
Cc: <stable@vger.kernel.org>
Link: https://lore.kernel.org/r/20201015160020.293748-1-avagin@gmail.com
---
kernel/futex.c | 5 +++++
1 file changed, 5 insertions(+)
diff --git a/kernel/futex.c b/kernel/futex.c
index 680854d..be68ac0 100644
--- a/kernel/futex.c
+++ b/kernel/futex.c
@@ -39,6 +39,7 @@
#include <linux/freezer.h>
#include <linux/memblock.h>
#include <linux/fault-inject.h>
+#include <linux/time_namespace.h>
#include <asm/futex.h>
@@ -3797,6 +3798,8 @@ SYSCALL_DEFINE6(futex, u32 __user *, uaddr, int, op, u32, val,
t = timespec64_to_ktime(ts);
if (cmd == FUTEX_WAIT)
t = ktime_add_safe(ktime_get(), t);
+ else if (!(op & FUTEX_CLOCK_REALTIME))
+ t = timens_ktime_to_host(CLOCK_MONOTONIC, t);
tp = &t;
}
/*
@@ -3989,6 +3992,8 @@ SYSCALL_DEFINE6(futex_time32, u32 __user *, uaddr, int, op, u32, val,
t = timespec64_to_ktime(ts);
if (cmd == FUTEX_WAIT)
t = ktime_add_safe(ktime_get(), t);
+ else if (!(op & FUTEX_CLOCK_REALTIME))
+ t = timens_ktime_to_host(CLOCK_MONOTONIC, t);
tp = &t;
}
if (cmd == FUTEX_REQUEUE || cmd == FUTEX_CMP_REQUEUE ||
^ permalink raw reply related [flat|nested] 3+ messages in thread
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2020-10-15 16:02 ` Dmitry Safonov
2020-10-20 15:11 ` [tip: timers/urgent] futex: Adjust absolute futex timeouts with per time namespace offset tip-bot2 for Andrei Vagin
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