Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]

Groups > linux.kernel > #1738698

[PATCH review for 4.9 42/50] hrtimer: Catch invalid clockids again

Show all headers | View raw

From: Marc Zyngier <marc.zyngier@arm.com>

[ Upstream commit 336a9cde10d641e70bac67d90ae91b3190c3edca ]

commit 82e88ff1ea94 ("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>
Signed-off-by: Sasha Levin <alexander.levin@verizon.com>
---
 kernel/time/hrtimer.c | 20 +++++++++++++++-----
 1 file changed, 15 insertions(+), 5 deletions(-)

diff --git a/kernel/time/hrtimer.c b/kernel/time/hrtimer.c
index bb5ec425dfe0..eeb7f2f5698d 100644
--- a/kernel/time/hrtimer.c
+++ b/kernel/time/hrtimer.c
@@ -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
@@ -1112,6 +1110,18 @@ 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)
 {
-- 
2.11.0

Back to linux.kernel | Previous | Next — Previous in thread | Next in thread | Find similar | Unroll thread

Thread

[PATCH review for 4.9 01/50] xen-netback: Use GFP_ATOMIC to allocate  hash "Levin, Alexander (Sasha Levin)" <alexander.levin@verizon.com> - 2017-09-25 03:40 +0200
  [PATCH review for 4.9 17/50] f2fs: do not wait for writeback in  write_begin "Levin, Alexander (Sasha Levin)" <alexander.levin@verizon.com> - 2017-09-25 03:40 +0200
  [PATCH review for 4.9 15/50] sched/fair: Update rq clock before  changing a task's CPU affinity "Levin, Alexander (Sasha Levin)" <alexander.levin@verizon.com> - 2017-09-25 03:40 +0200
  [PATCH review for 4.9 26/50] ASoC: mediatek: add I2C dependency for  CS42XX8 "Levin, Alexander (Sasha Levin)" <alexander.levin@verizon.com> - 2017-09-25 03:40 +0200
  [PATCH review for 4.9 42/50] hrtimer: Catch invalid clockids again "Levin, Alexander (Sasha Levin)" <alexander.levin@verizon.com> - 2017-09-25 03:40 +0200
  [PATCH review for 4.9 06/50] mac80211_hwsim: check  HWSIM_ATTR_RADIO_NAME length "Levin, Alexander (Sasha Levin)" <alexander.levin@verizon.com> - 2017-09-25 03:40 +0200
  [PATCH review for 4.9 07/50] ALSA: hda: Add Geminilake HDMI codec ID "Levin, Alexander (Sasha Levin)" <alexander.levin@verizon.com> - 2017-09-25 03:40 +0200
  [PATCH review for 4.9 05/50] initramfs: finish fput() before  accessing any binary from initramfs "Levin, Alexander (Sasha Levin)" <alexander.levin@verizon.com> - 2017-09-25 03:40 +0200
  [PATCH review for 4.9 14/50] f2fs: do SSR for data when there is  enough free space "Levin, Alexander (Sasha Levin)" <alexander.levin@verizon.com> - 2017-09-25 03:40 +0200
  [PATCH review for 4.9 02/50] locking/lockdep: Add nest_lock integrity  test "Levin, Alexander (Sasha Levin)" <alexander.levin@verizon.com> - 2017-09-25 03:40 +0200
  [PATCH review for 4.9 18/50] md/linear: shutup lockdep warnning "Levin, Alexander (Sasha Levin)" <alexander.levin@verizon.com> - 2017-09-25 03:40 +0200
  [PATCH review for 4.9 12/50] netfilter: nf_ct_expect: Change  __nf_ct_expect_check() return value. "Levin, Alexander (Sasha Levin)" <alexander.levin@verizon.com> - 2017-09-25 03:40 +0200
  [PATCH review for 4.9 24/50] slub: do not merge cache if slub_debug  contains a never-merge flag "Levin, Alexander (Sasha Levin)" <alexander.levin@verizon.com> - 2017-09-25 03:40 +0200

csiph-web