Re: PowerPC exec page protection

Anton Blanchard
2004-04-14T08:48:26Z

Hi,

> <asm-ppc/pgtable.h> and <asm-ppc64/pgtable.h> both define the
> following map of protection bits:
>
> #define __P000 PAGE_NONE
> #define __P001 PAGE_READONLY_X
> #define __P010 PAGE_COPY
> #define __P011 PAGE_COPY_X
> #define __P100 PAGE_READONLY
> #define __P101 PAGE_READONLY_X
> #define __P110 PAGE_COPY
> #define __P111 PAGE_COPY_X
>
> #define __S000 PAGE_NONE
> #define __S001 PAGE_READONLY_X
> #define __S010 PAGE_SHARED
> #define __S011 PAGE_SHARED_X
> #define __S100 PAGE_READONLY
> #define __S101 PAGE_READONLY_X
> #define __S110 PAGE_SHARED
> #define __S111 PAGE_SHARED_X
>
> The _X flags seem wrongly placed, as bit 2 is the PROT_EXEC bit, not
> bit 0. Is the above intentional?

Its backwards and we know it :) Ive got a patch to implement per page
execute on ppc64 and that did pop up.

Thanks for pointing it out, are you looking at ppc* page protection or
just chanced upon it?

Anton