Messages in this thread Patch in this message | | | From | Linke Li <> | Subject | [PATCH] MIPS: Fix undefined behavior in PAGE_MASK calculation | Date | Sun, 9 Jul 2023 14:49:12 +0800 |
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From: Linke Li <lilinke99@gmail.com>
Make PAGE_MASK an unsigned long, like it is on x86, to avoid:
../arch/mips/include/asm/ginvt.h:44:20: warning: shifting a negative signed value is undefined [-Wshift-negative-value] addr &= PAGE_MASK << 1;
In the MIPS architecture, the PAGE_MASK definition in arch/mips/include/asm/page.h leads to shifting a negative signed value, which is undefined according to the language specification. To address this issue, the PAGE_MASK definition is modified to be unsigned long and ensure well-defined behavior.
Signed-off-by: Linke Li <lilinke99@gmail.com> --- arch/mips/include/asm/page.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/arch/mips/include/asm/page.h b/arch/mips/include/asm/page.h index 5978a8dfb917..3061a5586954 100644 --- a/arch/mips/include/asm/page.h +++ b/arch/mips/include/asm/page.h @@ -33,7 +33,7 @@ #define PAGE_SHIFT 16 #endif #define PAGE_SIZE (_AC(1,UL) << PAGE_SHIFT) -#define PAGE_MASK (~((1 << PAGE_SHIFT) - 1)) +#define PAGE_MASK (~(PAGE_SIZE - 1)) /* * This is used for calculating the real page sizes -- 2.25.1
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