From 3477f08b08da6bfd904218fdb76b3db592dd7ebd Mon Sep 17 00:00:00 2001
From: Xiang W <wxjstz@126.com>
Date: Wed, 15 Sep 2021 14:50:52 +0800
Subject: lib: sbi: fix ctz bug
The original version of ctz will cause an endless loop, if the parameter
passed in is 0. This commit fixes this bug.
Signed-off-by: Xiang W <wxjstz@126.com>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
Reviewed-by: Anup Patel <anup.patel@wdc.com>
---
lib/sbi/riscv_asm.c | 3 +++
1 file changed, 3 insertions(+)
diff --git a/lib/sbi/riscv_asm.c b/lib/sbi/riscv_asm.c
index 4c24a51..d7b9b2b 100644
--- a/lib/sbi/riscv_asm.c
+++ b/lib/sbi/riscv_asm.c
@@ -213,6 +213,9 @@ static unsigned long ctz(unsigned long x)
{
unsigned long ret = 0;
+ if (x == 0)
+ return 8 * sizeof(x);
+
while (!(x & 1UL)) {
ret++;
x = x >> 1;
--
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