On Thu, Nov 27, 2008 at 03:12:38PM +0000, David Howells wrote: > Fix the error handling in sys_mmap2(). Currently, if the pgoff check fails, > fput() might have to be called (which it isn't), so do the pgoff check first, > before fget() is called. *sigh*. My reaction was "Why do we have sys_mmap2 in every architecture?" So I started looking. Oh dear, oh dear oh dear. FRV: /* As with sparc32, make sure the shift for mmap2 is constant (12), no matter what PAGE_SIZE we have.... */ ia64: Just uses PAGE_SIZE (currently supported values: 4k, 8k, 16k and 64k). So what is poor userspace to do? Check which architecture it's on and figure out what PAGE_SIZE to use for mmap2 based on that? How about we introduce a sys_mmap6() in common code which takes 'off' in multiples of 4k. Then FRV and other sane architectures can replace their sys_mmap2 entries in their syscall tables with sys_mmap6. ia64 has to keep its insane sys_mmap2 entry, but it can add a sys_mmap6 entry too. -- Matthew Wilcox Intel Open Source Technology Centre "Bill, look, we understand that you're interested in selling us this operating system, but compare it to ours. We can't possibly take such a retrograde step." -- To unsubscribe from this list: send the line "unsubscribe kernel-janitors" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html