Messages in this thread Patch in this message | | | Date | Wed, 16 Jan 2008 16:47:10 +0100 | From | Ingo Molnar <> | Subject | Re: [PATCH 0 of 4] x86: some more patches |
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* Jan Beulich <jbeulich@novell.com> wrote:
> > Yes, but if you cast to long the result will be 32bit again. Or do > > you rely on it being always used in 64bit signed context with sign > > extension? While that might work it would seem rather fragile to me, > > just asking for similar future bugs. > > Even if conversion is to 64-bit unsigned, the value (being signed) > will be sign-extended first (to preserve its value modulo 2**<target > type width>).
yes. It would be nice if Andi could test my fix instead of arguing why he thinks it's unlikely to work ;-)
(i've got the cleanup patch below as well ontop of today's x86.git which includes the first fix, but it's an RFC as it has wider impact and might break stuff.)
Ingo
---------------> Subject: x86: PAGE_MASK cleanup From: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Ingo Molnar <mingo@elte.hu> --- include/asm-x86/page.h | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)
Index: linux-x86.q/include/asm-x86/page.h =================================================================== --- linux-x86.q.orig/include/asm-x86/page.h +++ linux-x86.q/include/asm-x86/page.h @@ -6,12 +6,12 @@ /* PAGE_SHIFT determines the page size */ #define PAGE_SHIFT 12 #define PAGE_SIZE (_AC(1,UL) << PAGE_SHIFT) -#define PAGE_MASK (~(PAGE_SIZE-1)) +#define PAGE_MASK (_AT(phys_addr_t, ~(PAGE_SIZE-1))) #ifdef __KERNEL__ #define PHYSICAL_PAGE_MASK (PAGE_MASK & __PHYSICAL_MASK) -#define PTE_MASK (_AT(long, PHYSICAL_PAGE_MASK)) +#define PTE_MASK PHYSICAL_PAGE_MASK #define LARGE_PAGE_SIZE (_AC(1,UL) << PMD_SHIFT) #define LARGE_PAGE_MASK (~(LARGE_PAGE_SIZE-1))
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