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    SubjectRe: [PATCH v3 0/3] preadv & pwritev syscalls.
    On Mon, Dec 15, 2008 at 12:36:14PM +0100, Gerd Hoffmann wrote:

    > Next revision of the patch series, with the alignment issue fixed by
    > swapping the last two arguments as suggested by arch maintainers.
    >
    > I've dropped the now-obsolete wrappers for mips. Ralf, please
    > double-check.

    It fixes the alignment issue but still won't work; on MIPS 32-bit userspace
    will pass the 64-bit argument in two registers but the 64-bit kernel code
    will assume it to be passed in a single registers. It'd be ugly but passing
    a pointer to a 64-bit argument would solve the issue; something like this:

    sys_preadv(unsigned long fd, const struct iovec __user *vec,
    unsigned long vlen, loff_t __user *pos);
    compat_sys_preadv(unsigned long fd, const struct compat_iovec __user *vec,
    unsigned long vlen, loff_t __user *pos);

    sys_splice uses loff_t __user * arguments as well and that's why it's
    doesn't need any compat wrapper.

    I'm surprised this works for x86; does x86-64 code really expect 64-bit
    arguments as 2 32-bit arguments?

    Patch 1/3 looks like it's a bug fix and you may want to submit this
    separate from the remainder of the series for 2.6.28?

    Ralf


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