On Tue, 2008-06-10 at 15:14 -0700, Andrew Morton wrote: > On Tue, 10 Jun 2008 18:01:07 -0400 > Dave Kleikamp <[EMAIL PROTECTED]> wrote: > > > mm: Allow architectures to define additional protection bits > > > > This patch allows architectures to define functions to deal with > > additional protections bits for mmap() and mprotect(). > > > > arch_calc_vm_prot_bits() maps additonal protection bits to vm_flags > > arch_vm_get_page_prot() maps additional vm_flags to the vma's vm_page_prot > > arch_validate_prot() checks for valid values of the protection bits > > > > Note: vm_get_page_prot() is now pretty ugly. Suggestions? > > It didn't get any better, no ;) > > I wonder if we can do the ORing after doing the protection_map[] > lookup. I guess that's illogical even if it happens to work.
I guess we can live with it. Just holding out hope that someone might see a nicer way to do it. > > diff -Nurp linux001/include/linux/mman.h linux002/include/linux/mman.h > > --- linux001/include/linux/mman.h 2008-06-05 10:08:01.000000000 -0500 > > +++ linux002/include/linux/mman.h 2008-06-10 16:48:59.000000000 -0500 > > @@ -34,6 +34,26 @@ static inline void vm_unacct_memory(long > > } > > > > /* > > + * Allow architectures to handle additional protection bits > > + */ > > + > > +#ifndef HAVE_ARCH_PROT_BITS > > +#define arch_calc_vm_prot_bits(prot) 0 > > +#define arch_vm_get_page_prot(vm_flags) __pgprot(0) > > + > > +/* > > + * This is called from mprotect(). PROT_GROWSDOWN and PROT_GROWSUP have > > + * already been masked out. > > + * > > + * Returns true if the prot flags are valid > > + */ > > +static inline int arch_validate_prot(unsigned long prot) > > +{ > > + return (prot & ~(PROT_READ | PROT_WRITE | PROT_EXEC | PROT_SEM)) == 0; > > +} > > +#endif /* HAVE_ARCH_PROT_BITS */ > > argh, another HAVE_ARCH_foo. Sorry. I didn't realize HAVE_ARCH_foo was so evil. > A good (but verbose) way of doing this is to nuke the ifdefs and just > go and define these three things for each architecture. That can be > done via copy-n-paste into include/asm-*/mman.h or #include > <asm-generic/arch-mman.h>(?) within each asm/mman.h. > > Another way would be > > #ifndef arch_calc_vm_prot_bits > #define arch_calc_vm_prot_bits(prot) ... I think I prefer this method. I'll get rid of HAVE_ARCH_PROT_BITS. Thanks, Shaggy -- David Kleikamp IBM Linux Technology Center _______________________________________________ Linuxppc-dev mailing list Linuxppc-dev@ozlabs.org https://ozlabs.org/mailman/listinfo/linuxppc-dev