[patch 06/46] Fix timeout overflow with jiffies

[Thomas Gleixner]

From: Ingo Molnar <mingo@xxxxxxx>

Prevent timeout overflow if timer ticks are behind jiffies (due to high
softirq load or due to dyntick), by limiting the valid timeout range to
MAX_LONG/2.

Signed-off-by: Ingo Molnar <mingo@xxxxxxx>
Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxx>
---

 include/linux/jiffies.h |    4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

Index: linux-2.6.20-rc4-mm1-bo/include/linux/jiffies.h
===================================================================
--- linux-2.6.20-rc4-mm1-bo.orig/include/linux/jiffies.h
+++ linux-2.6.20-rc4-mm1-bo/include/linux/jiffies.h
@@ -142,13 +142,13 @@ static inline u64 get_jiffies_64(void)
  *
  * And some not so obvious.
  *
- * Note that we don't want to return MAX_LONG, because
+ * Note that we don't want to return LONG_MAX, because
  * for various timeout reasons we often end up having
  * to wait "jiffies+1" in order to guarantee that we wait
  * at _least_ "jiffies" - so "jiffies+1" had better still
  * be positive.
  */
-#define MAX_JIFFY_OFFSET ((~0UL >> 1)-1)
+#define MAX_JIFFY_OFFSET ((LONG_MAX >> 1)-1)
 
 /*
  * We want to do realistic conversions of time so we need to use the same

--

-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/