The set of addresses that the code of a process is able to refer to during its execution. Note that the ability of a process to refer to some addresses doesn't mean that actual memory is allocated at those addresses.
Questions tagged [address-space]
79 questions
1
vote
2 answers
Basic C++ pointer questions on dereferencing and address-space
In the following code, based on reading cplusplus.com, I'm trying to test my basic understanding on pointers.
#include
using namespace std;
int main() {
int foo, *bar, fubar;
foo = 81;
bar = &foo;
fubar = *bar;
cout…
ja_him
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0
votes
3 answers
lowest and highest address in memorey where smallest accesible unit is 4 bytes
A question was asked saying "what is the lowest and highest address given 2^10 bytes of memory in which 4 byte word is the smallest addressable unit?"
The lowest address is 0
The answer key has the highest address 2^10-4 I thought it would be…
user796388
0
votes
0 answers
Are executable files virtual addresses shown by disassemblers definitive?
I'm on a macOS x86_64 system.
I have this little C program in a file named test.c :
void fx(){
int y = 20;
y++;
}
int main(){
int x = 10;
x++;
fx();
}
If I compile this with "clang test.c -o test" and then…
alessio solari
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0
votes
0 answers
Why do class D and E IP-addresses have no subnet mask?
As specified on most sites, Class D IP adresses for instance, range from 224.0.0.0 to 239.255.255.255. So their respective Subnet mask should be 255.0.0.0 right? If you look it up, that is not the case, it is stated that D and E have no subnet…
Lorenz Hack
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- 2
0
votes
2 answers
Is PCI "CF8h/CFCh" IO port addresses only applicable to processors with an IO address space?
Some CPU like x86 processor has two address spaces. One for memory and one for IO. And different instructions to access them.
And the PCI 3.0 spec also mentions some important IO addresses:
Two DWORD I/O locations are used to generate…
smwikipedia
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0
votes
1 answer
Question about memory space in microprocessor
My teacher has given me the question to differentiate the maximum memory space of 1MB and 4GB microprocessor. Does anyone know how to answer this question apart from size mentioned difference ?
https://i.stack.imgur.com/Q4Ih7.png
kaito kumon
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0
votes
0 answers
If the register holding the logical Byte address of a program is the PROGRAM COUNTER then what is the register holding the actual physical address?
What is the general name of the register holding the physical address of a Byte of a program after the logical address is translated by the MMU ?
Kode1000
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- 3
0
votes
1 answer
How can I determine if Windows applies ASLR without rebooting?
As far as I understand, ASLR Address Space Layout Randomization will only do random relocation per system start (per reboot).
Address Space Layout Randomization (ASLR)
ASLR moves executable images into random locations when a system
boots, making…
Martin Ba
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0
votes
1 answer
Can x86 cpu read or write on physical address which is larger than RAM?
I'm doing operating system lab on QEMU. I found that read/write is allowed when accessing physical address after paging which is larger than RAM. Is it the same condition on a real x86 machine? Will x32 or x64 cause different results?
cyyzero
- 1
0
votes
0 answers
What is the purpose of two address spaces in x86?
As I know, nowdays, x86's IO address space is used almost only for legacy devices. E.g ARM and RISC-V have only one address space, so, what is the idea behind multiple address spaces?
ser
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0
votes
2 answers
How 4gb(VM) Address space used while swithcing from/to user space to kernel space
I looked at a lot if online thread/tutorials regarding how process address space is divided into process/kernel
Ex:
i have some Helloworld program
in that i have call as printf(in turn it makes write system call to enter into kernel space)
My doubt…
0
votes
2 answers
Why is the heap section present when there are no malloc used
I am trying to find out whether heap exists in the address space of the process, if we don't call malloc.
#include
int main()
{
getchar();
return 0;
}
Heap section is present in the maps even if i dont call malloc
cat…
md.jamal
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0
votes
0 answers
Differentiate .BSS from Heap Accesses
As I understand, the [heap] virtual memory area (VMA) in the process address space in Linux, contains both the .bss data and the heap data (Link).
I want to capture heap accesses in the [heap] VMA. Again as far as I know, .bss mappings happen at…
TheAhmad
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0
votes
1 answer
OpenSHMEM on multiple linux machines
Is it possible to run OpenSHMEM on multiple Linux machines? I want Google Compute Engine VMs to work as PEs in OpenSHMEM.
Mantas
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0
votes
1 answer
If you have a physical address, is it possible to traverse the paging structures backwards and compute a linear address?
So, my question is a bit ridiculous I guess and crazy.
I don't see why you ever need to go from a physical address back to a linear one.
Nonetheless, is it possible?
matrix4
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