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big usermem kernel patch

Greetings!  It seems that we are in need of a 'big usermem' kernel
patch in Debian, so I am considering contributing such a package.  It
appears there are two approaches on the net, both in various
incarnations of redhat:

1) user-tunable /proc/self/mapped_base -- this allows setuid processes
   to move the base address at which shared libs are mapped from the
   default (on x86) of 0x40000000, allowing for much larger contiguous
   brk *or* mmaped space (up to 2.7 GB -- the oracle docs appear to
   refer to this.  See also WOLK).

2) In RHEL3, the kernel maps PROT_EXEC maps below the executable, and
   other maps down from the stack, giving an undivided brk/mmap area.
   this seems best, but I can't yet find the RH patch anywhere.  (See
   RH bugzilla 104583).

Ideas?  I'm looking to allow users procs in Debian to allocate the
largest continuous block possible, either through brk or mmap (at the
user's choice).

Take care,

Camm Maguire			     			camm@enhanced.com
"The earth is but one country, and mankind its citizens."  --  Baha'u'llah

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