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    SubjectPATCH: was Re: mmap bug in 2.2.13 (or in documentation)
    James Manning wrote:
    >
    > [ Wednesday, December 29, 1999 ] Abramo Bagnara wrote:
    > > Cause the fall through in do_mmap (around mm/mmap.c:223) all kind of
    > > file mmap are denied with EACCES if file is not open for reading.
    > > This is contrary to mmap(2):
    > >
    > > Another for me incomprehensible option is that mmap(2) is wrong... can
    > > someone clarify this?
    >
    > I started a small lkml thread about this when I saw the same problem
    > a couple of months back... since other OS's that I checked had the
    > same restriction, and since replacing my creat()'s with open(O_RDWR)
    > wasn't a big deal, I just tagged it as a doc bug... I couldn't think
    > of a situation where you'd *want/need* to make write-only mmap'd area,
    > so this seems fine to me (you could even #define your creat() if you
    > don't want to change the code)

    Ok, taken in account that nobody has taken back you, I assumed that your
    interpretation is good (doc bug).
    This is a patch to remove an useless (and confusing) check in mm/mmap.c.
    Please apply.

    --
    Abramo Bagnara mailto:abramo@alsa-project.org

    Opera Unica
    Via Emilia Interna, 140 Phone: +39.0546.656023
    48014 Castel Bolognese (RA) - Italy Fax: +39.0546.656023

    ALSA project is http://www.alsa-project.org
    sponsored by SuSE Linux http://www.suse.com

    It sounds good!--- mm/mmap.c.~1~ Thu Oct 21 17:04:37 1999
    +++ mm/mmap.c Mon Dec 27 09:13:52 1999
    @@ -258,8 +258,7 @@
    vma->vm_flags = vm_flags(prot,flags) | mm->def_flags;

    if (file) {
    - if (file->f_mode & 1)
    - vma->vm_flags |= VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC;
    + vma->vm_flags |= VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC;
    if (flags & MAP_SHARED) {
    vma->vm_flags |= VM_SHARED | VM_MAYSHARE;
    \
     
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