2
votes
2answers
99 views

Are system calls the only way to interact with the Linux kernel from user land?

Are there any other interfaces, e.g. the /proc filesystem?
3
votes
1answer
43 views

Result from kernel returned to what process?

When a process requires actions that require kernel mode, it uses a system call. So, how are the results returned to the process?
3
votes
3answers
92 views

API with no system calls

The book 'Understanding Linux Kernel' says that 'for something abstract such as math functions, there may be no reason to make system calls'. Can any one please explain how is a system call not ...
0
votes
1answer
111 views

what is a Kernel? [closed]

I'm learning Unix from the Unix Architecture book by Maurice J Bach. So if my question seems too stupid, please do bear with it. I read a few related questions but I would like a more simple ...
5
votes
2answers
85 views

Making a process read a different file for the same filename

I have an application that reads a file. Let's call it processname and the file ~/.configuration. When processname runs it always reads ~/.configuration and can't be configured differently. There are ...
0
votes
1answer
118 views

Understanding a XINU system call - getstk.c [closed]

I am having trouble conceptually understanding what is going on towards the end of this system call, and why. I understand the getstk.c method returns the highest memory address of available space, ...
1
vote
0answers
251 views

Why system call hooking produces different result everytime in Linux/Android 2.6.29?

I have implemented system call hooking for Android 2.6.29 kernel through a LKM module. I am tracing down one Android app for system calls. But interestingly, it returns different results every time I ...
2
votes
1answer
328 views

How to decode cmd = 3222823425 in ioctl in Linux 2.6.29

I am just confused like how can I break cmd=3222823425 value into different parts to figure out what this command means actually in the Linux kernel. I know, some functions are making ioctl command ...
3
votes
2answers
2k views

Adding a new System call to Linux 3.2.x with a loadable kernel module [closed]

I want to add a particular new system call in the linux kernel 3.2.x but as a loadable kernel module (as I don't want to recompile the kernel again and again) I read through many posts on internet ...
0
votes
0answers
410 views

adding system calls to kernel without recompiling during implementation

Could anyone tell me if it is possible to add several system calls to the linux kernel (version 2.6.35) and not have to recompile the kernel each time I change one of their implementations (i.e. ...
3
votes
1answer
2k views

getrusage system call: what is “maximum resident set size”

man getrusage 2 says ru_maxrss (since Linux 2.6.32) This is the maximum resident set size used (in kilobytes). For RUSAGE_CHILDREN, this is the resident set size of the largest ...
4
votes
1answer
405 views

System call invokation methods in new kernel

I read that in the newer kernels system calls are invoked using the INT X80 instruction and also using the sysenter instruction. And also the sysenter instruction gives faster invocation as compared ...
2
votes
1answer
1k views

Linux source, where are sys_umount and sys_mount system calls? [duplicate]

Possible Duplicate: Understanding the linux kernel source I am sure that I must be missing something, here. I cannot for the life of me find the source code for these system calls. I can ...
9
votes
2answers
1k views

Interruption of system calls when a signal is caught

From reading the man pages on the read() and write() calls it appears that these calls get interrupted by signals regardless of whether they have to block or not. In particular, assume a process ...
4
votes
1answer
2k views

Hung system call

So I'm working with a custom kernel module that I'm writing a python front end for. The kernel module works, and it adds a framebuffer device file to /dev/fb1. I can read and write to it fine. I've ...