sharing of pages

sharing of pages

Post by Eric Shapo » Sat, 07 Nov 1998 04:00:00

Hi All--
  Here is a senario that I would like to implement in a device driver.
I have a page of memory in my driver.  This is page locked memory.  I
would like to be able to have an application write to this one specific
page as well, without going through a kernel call.  Basically I want a
way to insert this page into the process memory space.  Is there any way
that I can do this?  The goal of all this is to implement a tracing
system (for debugging my driver) where the driver can insert data into
this page, as well as the application.

  I am working with a driver written for NT, that needs to be moved to
some other os's. ;)  It has this feature, and is prety nice for
debugging.  I would like to be able to leave it in, and just recreate
the initial setup of this system under Linux.

  Any help would be greatly appreciated.


Eric Shapow


1. Does Shared Text pages are writable ?


Does shared text pages are writable ? instead of copy-on-write,  in
Solaris ?

The reason i am asking this is, if i have two programs in same



i compile above program as cc one.c, it generates a.out. I run it....

form another window, i compile following program(In same directory)



as cc two.c. When i compile two.c it also creates a.out in same
That is why SOMETIMES (Not always) the one.c which is running in
previous window gives Bus error. But sometimes automatically it starts
printing 2's without giving SIGBUS in first window. So this gives me
the impression that when compiler tries to write image into a.out
for secondtime (two.c), it finds a.out pages  into memory running, so it

simply writes into those pages.


"it is not the style of clothes one wears, neither the kind of
automobile one drives, nor the amount of money one has in the
bank, that counts. These mean nothing. It is simply service that
measures success."
                  Dr. George Washington Carver.

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