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authorThomas Gleixner <tglx@linutronix.de>2007-04-09 00:03:30 +0200
committerAdrian Bunk <bunk@stusta.de>2007-04-09 00:03:30 +0200
commit812b03dc31229847825989f5e35359a7c4dff6f4 (patch)
treec684880491774be3b261f00f18e523dd0cb391d9 /include
parent2c461b3302b33de1500267a11cc50e29f33cbde6 (diff)
prevent timespec/timeval to ktime_t overflow
Frank v. Waveren pointed out that on 64bit machines the timespec to ktime_t conversion might overflow. This is also true for timeval to time_t conversions. This breaks a "sleep inf" on 64bit machines. While a timespec/timeval with tx.sec = MAX_LONG is valid by specification the internal representation of ktime_t is based on nanoseconds. The conversion of seconds to nanoseconds overflows for seconds values >= (MAX_LONG / NSEC_PER_SEC). Check the seconds argument to the conversion and limit it to the maximum time which can be represented by ktime_t. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Adrian Bunk <bunk@stusta.de>
Diffstat (limited to 'include')
-rw-r--r--include/linux/ktime.h7
1 files changed, 6 insertions, 1 deletions
diff --git a/include/linux/ktime.h b/include/linux/ktime.h
index f3dec45ef874..f106701d7dbd 100644
--- a/include/linux/ktime.h
+++ b/include/linux/ktime.h
@@ -56,7 +56,8 @@ typedef union {
#endif
} ktime_t;
-#define KTIME_MAX (~((u64)1 << 63))
+#define KTIME_MAX ((s64)~((u64)1 << 63))
+#define KTIME_SEC_MAX (KTIME_MAX / NSEC_PER_SEC)
/*
* ktime_t definitions when using the 64-bit scalar representation:
@@ -77,6 +78,10 @@ typedef union {
*/
static inline ktime_t ktime_set(const long secs, const unsigned long nsecs)
{
+#if (BITS_PER_LONG == 64)
+ if (unlikely(secs >= KTIME_SEC_MAX))
+ return (ktime_t){ .tv64 = KTIME_MAX };
+#endif
return (ktime_t) { .tv64 = (s64)secs * NSEC_PER_SEC + (s64)nsecs };
}