> I have written a daemon which creates a shared memory and puts in
> the data. Then i have a kernel module which is always installed
after
> starting the daemon. But when I try to access the shared memory that
> has been created using the daemon I am not seeing any data that has
> been put in by the daemon.
Shared memory is for communicating between two user space processes.
It is the wrong approach if you want to pass data between user-space
and kernel-space. You should use a device interface or use /proc.
> When i print the addresses of the shared memory I see
> different addresses. I am using the same key_t to in the kernel
> module ,which i used to create using the daemon, to access the
> shared memory. I am not understanding what is the problem...
I am not sure how you executed the equivalent of shmat() in the
kernel module. Even if you did, it would execute in the context of
some process ('insmod' if you are doing this at module init time).
Once the process dies, the shared memory mapping is no longer valid.
This may be the reason why you don't see the expected data.
But as I said, you shouldn't be doing things this way. So don't
bother debugging it..
-Ravi.
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