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From: Ahmad Fatoum <a.fatoum@pengutronix.de>
To: barebox@lists.infradead.org
Cc: Ahmad Fatoum <a.fatoum@pengutronix.de>
Subject: [PATCH 1/2] include: linux/math.h: promote DIV_ROUND_UP_ULL args to 64-bit
Date: Thu, 15 Aug 2024 08:56:45 +0200	[thread overview]
Message-ID: <20240815065646.1156788-1-a.fatoum@pengutronix.de> (raw)

DIV_ROUND_DOWN_ULL promotes division arguments to 64-bit, but
DIV_ROUND_UP_ULL did so only for the division, not the addition for the
round up. This would lead to a wrong result when the 32-bit addition
wraps around.

Linux has an explicit cast to fix this, so do likewise in barebox.

Signed-off-by: Ahmad Fatoum <a.fatoum@pengutronix.de>
---
 include/linux/math.h | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/include/linux/math.h b/include/linux/math.h
index acbffa96e6eb..f5d5cc714c4e 100644
--- a/include/linux/math.h
+++ b/include/linux/math.h
@@ -23,7 +23,8 @@
 #define DIV_ROUND_DOWN_ULL(ll, d) \
 	({ unsigned long long _tmp = (ll); do_div(_tmp, d); _tmp; })
 
-#define DIV_ROUND_UP_ULL(ll, d)		DIV_ROUND_DOWN_ULL((ll) + (d) - 1, (d))
+#define DIV_ROUND_UP_ULL(ll, d) \
+	DIV_ROUND_DOWN_ULL((unsigned long long)(ll) + (d) - 1, (d))
 
 #define DIV_ROUND_CLOSEST(x, divisor)(			\
 {							\
-- 
2.39.2




             reply	other threads:[~2024-08-15  6:57 UTC|newest]

Thread overview: 4+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2024-08-15  6:56 Ahmad Fatoum [this message]
2024-08-15  6:56 ` [PATCH 2/2] i2c: efi: use DIV_ROUND_UP_ULL instead of native division Ahmad Fatoum
2024-08-20  5:28   ` Tomas Marek
2024-08-20 12:07 ` [PATCH 1/2] include: linux/math.h: promote DIV_ROUND_UP_ULL args to 64-bit Sascha Hauer

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