Re: [PATCH] mk68k: Fix broken THREAD_SIZE_ORDER

From: Jiri Slaby
Date: Wed Feb 28 2024 - 04:11:23 EST


On 28. 02. 24, 9:58, Dawei Li wrote:
Current THREAD_SIZE_ORDER implementation for m68k is incorrect, fix it
by ilog2().

This is not a good commit log. Incorrect in what way and why is the fixed version correct? And what is affected? Note you're referring to a change which was done 14 years ago. It definitely must not be that incorrect (for everybody).

Fixes: cddafa3500fd ("m68k/m68knommu: merge MMU and non-MMU thread_info.h")
Signed-off-by: Dawei Li <dawei.li@xxxxxxxxxxxx>
Cc: stable@xxxxxxxxxxxxxxx
---
arch/m68k/include/asm/thread_info.h | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/arch/m68k/include/asm/thread_info.h b/arch/m68k/include/asm/thread_info.h
index 31be2ad999ca..50faecd6fc5f 100644
--- a/arch/m68k/include/asm/thread_info.h
+++ b/arch/m68k/include/asm/thread_info.h
@@ -19,7 +19,8 @@
#else
#define THREAD_SIZE PAGE_SIZE
#endif
-#define THREAD_SIZE_ORDER ((THREAD_SIZE / PAGE_SIZE) - 1)
+
+#define THREAD_SIZE_ORDER ilog2(THREAD_SIZE / PAGE_SIZE)
#ifndef __ASSEMBLY__

--
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