hrtimer: Catch invalid clockids again (336a9cde) · Commits · 戴 / test

commit ("hrtimer: Revert CLOCK_MONOTONIC_RAW support") removed unfortunately a sanity check in the hrtimer code which was part of that MONOTONIC_RAW patch series. It would have caught the bogus usage of CLOCK_MONOTONIC_RAW in the wireless code. So bring it back. It is way too easy to take any random clockid and feed it to the hrtimer subsystem. At best, it gets mapped to a monotonic base, but it would be better to just catch illegal values as early as possible. Detect invalid clockids, map them to CLOCK_MONOTONIC and emit a warning. [ tglx: Replaced the BUG by a WARN and gracefully map to CLOCK_MONOTONIC ] Signed-off-by:

Marc Zyngier <marc.zyngier@arm.com> Cc: Tomasz Nowicki <tn@semihalf.com> Cc: Christoffer Dall <christoffer.dall@linaro.org> Link: http://lkml.kernel.org/r/1452879670-16133-3-git-send-email-marc.zyngier@arm.com Signed-off-by:

Thomas Gleixner <tglx@linutronix.de>

kernel/time/hrtimer.c

+15 −5

Original line number	Diff line number	Diff line
		@@ -94,17 +94,15 @@ DEFINE_PER_CPU(struct hrtimer_cpu_base, hrtimer_bases) =
		};

		static const int hrtimer_clock_to_base_table[MAX_CLOCKS] = {
		/* Make sure we catch unsupported clockids */
		[0 ... MAX_CLOCKS - 1] = HRTIMER_MAX_CLOCK_BASES,

		[CLOCK_REALTIME] = HRTIMER_BASE_REALTIME,
		[CLOCK_MONOTONIC] = HRTIMER_BASE_MONOTONIC,
		[CLOCK_BOOTTIME] = HRTIMER_BASE_BOOTTIME,
		[CLOCK_TAI] = HRTIMER_BASE_TAI,
		};

		static inline int hrtimer_clockid_to_base(clockid_t clock_id)
		{
		return hrtimer_clock_to_base_table[clock_id];
		}

		/*
		* Functions and macros which are different for UP/SMP systems are kept in a
		* single place
		@@ -1081,6 +1079,18 @@ u64 hrtimer_get_next_event(void)
		}
		#endif

		static inline int hrtimer_clockid_to_base(clockid_t clock_id)
		{
		if (likely(clock_id < MAX_CLOCKS)) {
		int base = hrtimer_clock_to_base_table[clock_id];

		if (likely(base != HRTIMER_MAX_CLOCK_BASES))
		return base;
		}
		WARN(1, "Invalid clockid %d. Using MONOTONIC\n", clock_id);
		return HRTIMER_BASE_MONOTONIC;
		}

		static void __hrtimer_init(struct hrtimer *timer, clockid_t clock_id,
		enum hrtimer_mode mode)
		{

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