futex: Adjust absolute futex timeouts with per time namespace offset (c2f7d08c) · Commits · 戴 / test

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: ("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 −0

Original line number	Diff line number	Diff line
		@@ -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 \|\|

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