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@xxxxxxxxxxxxxxx>
> Fixes: 5a590f35add9 ("posix-clocks: Wire up clock_gettime() with timens offsets")
> Reported-by: Hans van der Laan <j.h.vanderlaan@xxxxxxxxxxxxxxxxxx>
> Signed-off-by: Andrei Vagin <avagin@xxxxxxxxx>
Reviewed-by: Dmitry Safonov <0x7f454c46@xxxxxxxxx>
> ---
>
> 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
