General :: Finding The Memory Address(in FLASH) Of A Command In Shell Script?
Mar 29, 2011
If i have a shell script to run on a Linux unit, which has a command to Reset(or say upgrade) the unit in between the script.Is it possible to find out the memory address of the next waiting command so that i can store the address to any environment variable in flash , then after Reset will continue Run from the stored address.
I'm looking for a way to get my IP address using the command prompt in Linux. I know when you type "ifconfig" you can get your local IP address (i.e. 192.168.0.103), but I'm looking for my IP address that I get from my ISP. How can I get this from Linux without having to visit some website?
when i send any packet to anu destination and want to see he mac address of source and destination i am using the command tcpdump -qec1 but rather then getting the mac address of source and destination each time i am getting mac address of the system which is broadcasting. will anybody tell me how can i get source and destination mac address even if any other packet is also being broadcast to my network.
how to calculate (if possible) the end address of an image file in a flash memory. I'm trying to create a checksum and checkheader function and the info that I got is the file's offset, how many sector it consumes and its size. I kinda need the end address, sad thing is, I don't know how to calculate it.test.img's start address is 0, the size is 0x20000 and consumes 3 sectors.
I am using malloc and frees a lot in my program. It shows its allocated but when i remove it doesnt show as the memory is removed(I am using the top command to view VIRT memory usage). If this continously grows what would happen to my program (Will it go out of memory?)
I want to get a list of all packages that provide a certain virtual package. A way of doing this would be to write a shell script that parses all output of Code: apt-cache search -f .* And spits out all packages that have the virtual package in the provides section. The problem with this approach is that it takes an awful long amount of time to execute. I guess that there should be a simple command that does this in an efficient manner, but which I wasn't able to find.
Im an academic (university networks and security lecturer) studying/teaching network and operating system security, and inspired by the work of Hovav Shacham set about testing ASLR on linux. Principley I did this by performing a brute force buffer overflow attack on Fedora 10 and Ubuntu 9. I did this by writting a little concurrent server daemon which accidently on purpose didnt do bounds checking.
I then wrote a client to send it a malicious string brute forcing guessed addresses which caused a return-to-libc to the function usleep with a parameter of 16m causing a delay of 16 seconds as laid out in [URL] Once I hit the delay I new I had found the function and could calculate delta_mmap allowing me to create a standard chained ret-to-libc attack. All of that works fine. However .... To complete my understanding I am trying establish where I can find the standard base address for ubuntu 9 (and other distros) for the following, taken from Shacham:-
Quote:
[code]....
/proc/uid/maps gives me some information but not the base address ldd also gives me the randomised starting address for sections in the user address space but neither gives me the base address. Intrestingly ... when a run ldd with aslr on for over (about) 100 times and checked the start point of libc I determined that the last 3 (least significant) hex digits were always 0's and the fist 4 (most significant) where between 0xB7D7 and 0xB7F9. To me this indicated that bits 22-31 were fixed and bits 12-21 were randomized with bits 11-0 fixed. Although even that doesnt define the boundaries observed correctly.
Note: I am replicating the attack to provide signatures to detect it using IDS, and for teaching purposes. I am NOT a hacker and if needed to could reply from my .ac.uk email address as verification.
I am writing an application that wants to access periphals registers outside the standard (allowed) memory area.
Doing so gets me "segmentation fault".
I know, this is natural behaviour.
One way of getting around this is writing the module which has to be loaded by linux. I will consider this some time later.
For now, I want to come to some quick result and allow linux or gcc compiler to write to those memory areas of periphals. Is there a direct way to do so?
I have installed Kubuntu Lucid x86 10.4 LTS for the first time. Has anyone got a link that explains how KPackageKit gets the IP address of the repositories? I can install packages using sudo apt-get install xxx OK . KpackageKit tells me I have updates from the repositories. I can select them all and apply , but I get an error that it can't find the repository under a 192.168.100.129:8080 address . Which is not a surprise . I am using mirror.optus.net as a repository and can ping it fine on the command line. So is there somewhere else that KPackageKit maps IP addreses ? I have tried another mirror mirror.aarnet.edu.au and got similar results. My local sub-net is not 192.168.100 and have tried setting fixed IP on the local sub-net and different DHCP addresses and still the same error.
When I try to access at physical address (0xD0000), we known that it is necessary to convert physical address to virtual address using function IOREMAP(0xD0000, 1024) and return me 0xC00D0000.
Now our doubt is when I have a board with I/O in address 0x150, is it necessary to convert this address to other virtual address??? or with inb(0x150) return me state of I/O in this address? How can I known where is this I/O address in my map memory?
I want to be able to use Ctrl+R to have reverse-i search. Also if I press Shift+Up Arrow after typing the first few characters of a recently executed command then the shell should complete the command by finding the most recent commmand having the same first few characters.
A process is trying one access to memory, for example through an array (ex.: vect[0]=123. What happens?
Here below what I guess but I'm not sure and accept any comment (please, distinguish between "the system" and "the CPU" in case).
Let's suppose swapping to disk disbled.
We have two scenarios: without and with cache.
If no cache is present in the system: 1. The CPU must discover the phys addr of vect[0] virtual addr. To do that, has to read from 3 (or 2 depending on the system?) pages tables, stored in memory as well. 2. The CPU writes to the final address.
These mean 4 memory accesses.
If cache is present: 1. Like above but, if the pages tables are in cache, we have 3 accesses to that. 2. If the req. page is not in cache, it's reads from ram and transferred to it. Afterwards, cache is written. In the best case we have 4 cache accesses.
I'm NOT referring to standard programs that allow you to view flash with internet explorer. I'm looking for a program in which i can create flash animated web icons.
i want to use sdcard as flash memory to port linux(uclinux) image , so that i can boot using my arm7(lpc2148) microcontrollerIn other words, can we use sda card to dump linux image and boot from microcontroller)
As i undertsand - out of 1GB of the virtual Address space for Kernel from 3GB to 4GB of the process address space, Kernel image (code, data, bss, stack, heap) resides staring @0x0 address. Vmalloc area starts either at the end of Physical ram size or at 896M. This 896M cap is mandated to ensure that minimum of 128MB is reserved as vmalloc_reserve for vmalloc,kmap etc.
Is the understanding correct? Now trying to map Physical Zones into this 1GB address space
Initial 16MB is mapped to ZONE_DMA 16MB - 896MB is mapped to ZONE_NORMAL 896MB - 1024MB is mapped to ZONE_HIGHMEM
Does this mean that Kernel image is residing in ZONE_DMA area? Any call to vmalloc() in kernel code will return address beyond 896M? insmod of any LKM will internally invoke vmalloc() to obtain contiguous area - where will this code physically located along with rest of kernel code in ZONE_DMA or in ZONE_HIGHMEM?
I am having a php script which is used for bulk mailing. I run the script every minute through cron job. I have mentioned the path of the php script in a .sh file and execute the .sh file through cron job. Every time i run the script it utilizes high memory which results to server crash. how to restrict memory usage for that process to be a minimum one or how to set priority to be low for that process so that it is executed when there is no high priority jobs, so that the server runs normally without going down when the script runs
is there a recursive shell or Perl script to delete files with the same name as the parent folder? i wish to include the starting folder name as argument to the script.
I need to process billions of small files using bash shell commands with limited memory size (256MB). If any of those files contain certain "keywords", the file will be removed. I tried with command:
Before buying an SD memory card, I'd like to know something more about the CPRM protection, in particular:Does CPRM influence the way I am supposed to access my own data? That is, does CPRM encrypt it? Could CPRM prevent me from accessing my own data?Is it possible to disable or eliminate CPRM from either the memory card or the card reader?Are there manufacturers selling CPRM-free SD memory cards?Is there any real alternative to CPRM-protected SD memory cards beside USB flash drives?Is Linux support for SD cards good?
Kernel 2.6.21.5, Slackware 12.0 A command line html reader, or a conversion tool from html to text is what I would like to know if any of you guys knows. It has not to do a perfect job. And it would be nice if it is a native unix/linux program.
If there is a command I can use to find specific file types? Say if I want to find all the jpg's in my home folder, but they don't have the .jpg extension in the name, how would I do it? Or can I set some kind of size parameter to find them? The ones I want are all from my digicam and roughly the same size.
Would like a command line list of commands, that I can print out, I know this would be allot of pages. I have tons of books and the net, but its a royal pain searching for the right command, need something I can flip through.
I want to pass ip address,port address and some parameters from command line using python script.The ip address and port address for establishing socket connection and remaining parameters to execute different connection.
I am total new to linux as I worked mostly on RTOS (symbian). My problem is, I need to find the file IOSTREAM.H and I am following commands below: 1) cd / 2) find . iostream.h ( finds the file / directory from the current path) It shows No such File or Directory