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From: ende.tan@starfivetech.com
To: linux-rt-users@vger.kernel.org, mtosatti@redhat.com
Cc: williams@redhat.com, jkacur@redhat.com,
	leyfoon.tan@starfivetech.com,
	Tan En De <ende.tan@starfivetech.com>
Subject: [1/1] rt-tests: queuelat: Fix wraparound in __clock_gettime()
Date: Mon, 11 Nov 2024 09:49:11 +0800	[thread overview]
Message-ID: <20241111014911.11571-1-ende.tan@starfivetech.com> (raw)

From: Tan En De <ende.tan@starfivetech.com>

Include tv_sec in addition to tv_nsec in __clock_gettime(). If the value
of variable 'a' wraps around, it may cause 'delta' to be negative, while
'delta' is defined with u64 type.

Signed-off-by: Tan En De <ende.tan@starfivetech.com>
---
 src/queuelat/queuelat.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/src/queuelat/queuelat.c b/src/queuelat/queuelat.c
index c549cd8..c057389 100644
--- a/src/queuelat/queuelat.c
+++ b/src/queuelat/queuelat.c
@@ -292,7 +292,8 @@ static inline unsigned long long __clock_gettime(void)
 	if (ret < 0)
 		return 0;
 
-	return now.tv_nsec;
+	// Combine seconds and nanoseconds into a single value in nanoseconds
+	return (unsigned long long)now.tv_sec * 1000000000ULL + now.tv_nsec;
 }
 
 #define gettick(val) do { (val) = __clock_gettime(); } while (0)
-- 
2.34.1


             reply	other threads:[~2024-11-11  5:21 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2024-11-11  1:49 ende.tan [this message]
2024-11-19 19:48 ` [1/1] rt-tests: queuelat: Fix wraparound in __clock_gettime() Marcelo Tosatti
2024-11-21 18:48 ` John Kacur

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