EmbLogic's Blog

MESSAGE QUEUES

while retriving or sending data using message queues are we allowed to use any pointer(“in” structure) to send or receive data ..

as my issue is i am not able to transmit or rather receive correct data using pointers..
have implemented same through using character array.

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What is Board setup file..?

Hi,

Going to write an I2C Driver, need to know the relationship between the core driver of bus and board setup file. I am using OMAP2 based ARM board. Just want to know about basic relationship.

Thanks

Manoj Arora

Posted in Device Drivers | Leave a comment

SELinux

If SELinux is enabled, the policy defines what access to resources and operations on them (e.g. read, write) are allowed (i.e. SELinux stops all access unless allowed by policy). This is why SELinux is called a ‘mandatory access control’ (MAC) system.
The policy design, implementation and testing against a defined security policy or requirements is important, otherwise there could be ‘a false sense of security’.
SELinux can confine an application within its own ‘domain’ and allow it to have the minimum privileges required to do its job. Should the application require access to networks or other applications (or their data), then (as part of the security policy design), this access would need to be granted (so at least it is known what interactions are allowed and what are not – a good security goal).
Should an application ‘do something’ it is not allowed by policy (intentional or otherwise), then SELinux would stop these actions.
Should an application ‘do something’ it is allowed by policy, then SELinux may contain any damage that maybe done intentional or otherwise. For example if an application is allowed to delete all of its data files or database entries, and the bug, virus or malicious user gains these privileges then it would be able to do the same, however the good news is that if the policy ‘confined’ the application and data, all your other data should still be there.
User login sessions can be confined to their own domains. This allows clients they run to be given only the privileges they need (e.g. admin users, sales staff users, HR staff users etc.). This again will confine/limit any damage or leakage of data.
Some applications (X-Windows for example) are difficult to confine as they are generally designed to have total access to all resources. SELinux can generally overcome these issues by providing sandboxing services.
SELinux will not stop memory leaks or buffer over-runs (because its not designed to do this), however it may contain the damage that maybe done.
SELinux will not stop all viruses/malware getting into the system (as there are many ways they could be introduced (including by legitimate users), however it should limit the damage or leaks they cause.
SELinux will not stop kernel vulnerabilities, however it may limit their effects.
It is very easy to add new rules to an SELinux policy using tools such as audit2allow(1) if a user has the relevant permissions, however be aware that this may start opening holes, so check what rules are really required.
Finally, SELinux cannot stop anything allowed by the security policy, so good design is important.

Posted in Uncategorized | 3 Comments

problem occured — server

clnt_create: RPC: Port mapper failure – Unable to send: errno 13 (Permission denied)

what it means about…..    ?

Posted in Project 1: A Linux Administration based Project | Leave a comment

what is subnet mask (255.255.255.0)

Definition: 255.255.255.0 is the most common subnet mask used on computers connected to Internet Protocol (IP)

What it means ?

Posted in Project 1: A Linux Administration based Project | 1 Comment

do i am able to share files NFS

if i and my friend am having the different internet connection of MTS data card.

but here the area is same, so the server may also same.

in this case do i able to share the files

Posted in Project 1: A Linux Administration based Project | Leave a comment

mac layer

Out of 7 layer in which MAC lie.

Posted in Project 1: A Linux Administration based Project, Uncategorized | 1 Comment

what is the significance of TTL (time to live)

what is the significance of TTL (time to live).

What Router do by decreasing TTL ?

 

Posted in Project 1: A Linux Administration based Project, Uncategorized | 1 Comment

MTU(maximum transmisson unit ) and DATAGRAM size different

MTU(maximum transmisson unit ) and DATAGRAM size different

why?

Posted in Project 1: A Linux Administration based Project | 1 Comment

Re:- Flash-Player

I have installed adobe-flash-player in fedora-16 64-bit.
But, I am not able to open/view emblogic documents, also not able to buffer youtube video.

Help me, as soon ….. Please :-)

Posted in Uncategorized | 3 Comments

PROJECT-1

I have completed the following topics::

Fedora installation

Kernel compilation

Gcc installation

Configure Raid

all servers

Created Usb media

Dual Boot

Debiyan installation

 

Posted in Linux Internals and System Programming | 1 Comment

Issue in Config of NFS Server

showmount -e 192.168.0.15
After typing this command it shows—
port mapper failure -unable to send : errno 101

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TO VAIBHAV SIR::

how to connect airtel 3G-e stick wid hp lappy amd 64 bitprocessor

Posted in Uncategorized | 1 Comment

To VARUN SIR — Board Bring Problem

i have already bring the board with the images given by you with 4GB and 2GB SD Card. Now I have got a delay after booting with 8GB SD Card….. as :

Starting Kernel……..

Uncompressing Linux…………………………………………………………………………………………………………………………………..

 

Plzzzz guide me where i m lacking…..

Posted in ARM Embedded Processors | 1 Comment

To VAIBHAV Sir facing issue with BusyBox CROSS_COMPILE

archival/libunarchive/get_header_tar.c: error: array subscript is above array bounds

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