Sponsored Content
Top Forums UNIX for Advanced & Expert Users Can kernel process access user address space ? Post 302259394 by subhotech on Tuesday 18th of November 2008 02:52:43 AM
Old 11-18-2008
MySQL Its a generic question , but your explanation makes alot of sense Thanks!

Its a generic question , but your explanation makes alot of sense Thanks!
Smilie
 

10 More Discussions You Might Find Interesting

1. UNIX for Dummies Questions & Answers

How to find the size of Process Address space.

Hello, Please help me to know, How to find out the how much amount of process addres space is required/is used for/by a process. Tnx & Regards Vishwa. (1 Reply)
Discussion started by: S.Vishwanath
1 Replies

2. Programming

Aplication user and kernel mode (data access)

Hi all, I am trying to setup a program to use a device driver and am confusing buffer access between User and Kernel mode. I think all applications running in User space have to communicate with the device drivers using io control calls and then have some functions called back from the driver... (1 Reply)
Discussion started by: Brendan Kennedy
1 Replies

3. HP-UX

How to restrict a user group to access the kernel

Hi, Please any one can help me to know that how we can restrict a user group to access the kernel at all. (0 Replies)
Discussion started by: harishankar
0 Replies

4. Programming

Access process memory from kernel space

Hi, I'm currently working on a project to help the analysis of malware from inside the kernel to avoid any kind of detection. So I need to be able to read the process memory from my kernel module. As of now, I'm stuck at converting a virtual memory address (for example 0x080483e8 found... (3 Replies)
Discussion started by: anonymoose
3 Replies

5. Programming

Find Virtual address space size for process

Hi, I am looking to work on unix systems which include (hp-ux, ibm aix, solaris and linux). I want to get the total virtual address space of a process, the used virtual memory i am able to get without any problem. I have tried using getrlimit and getrlimit64, but that gives only ... (4 Replies)
Discussion started by: uiqbal
4 Replies

6. UNIX for Advanced & Expert Users

wake up user space thread from kernel space ISR

Hello, I'm searching for a proper way to let the kernel space ISR(implemented in a kernel module) wake up a user space thread on a hardware interrupt. Except for sending a real-time signal, is it possible to use a semaphore? I've searched it on google, but it seems impossible to share a... (0 Replies)
Discussion started by: aaronwong
0 Replies

7. Programming

How to get address space size that a process is allowed to use

Hi All, From C++, I just want to find the address space size that a process is allowed to use. For ex, in 32 bit OS the allowed address space is 4GB and in 64 bit OS I guess this is 16GB or more. I jsut want to find it in my C++ project. Is there any API calls that gives me such information.... (2 Replies)
Discussion started by: Sendil Kumar
2 Replies

8. UNIX for Dummies Questions & Answers

Kernel/ user space and high/ low mem

Need some clarification on this.... 1. how are kernel/ user spaces and high/low memory related? 2. What do they all mean when i have the kernel command line as: "console=ttyS0,115200 root=/dev/sda2 rw mem=exactmap memmap=1M@0 memmap=96M@1M irqpoll" or 2. what do mem and memmap mean in... (3 Replies)
Discussion started by: dragonpoint
3 Replies

9. Programming

PC RAM and process address space

Suppose I have 3 gb of ram and 250 gb hard disk in my pc. Now I wrote a simple C program having only one statement malloc() to allocate 4 gb of memory as 32 bit os can address 4gb address space then will the malloc succeed? If yes then how it will get extra 1 gb of memory? Does the process gets... (3 Replies)
Discussion started by: rupeshkp728
3 Replies

10. UNIX for Advanced & Expert Users

Precaution to access user mode buffers from kernel

When accessing a user mode buffers from kernel space drivers what precautions must we take and how those precautions need to be implemented? (0 Replies)
Discussion started by: rupeshkp728
0 Replies
COPY(9) 						   BSD Kernel Developer's Manual						   COPY(9)

NAME
copy, copyin, copyout, copystr, copyinstr, copyoutstr -- kernel space to/from user space copy functions SYNOPSIS
#include <sys/types.h> #include <sys/systm.h> int copyin(const void *uaddr, void *kaddr, size_t len); int copyout(const void *kaddr, void *uaddr, size_t len); int copystr(const void *kfaddr, void *kdaddr, size_t len, size_t *done); int copyinstr(const void *uaddr, void *kaddr, size_t len, size_t *done); int copyoutstr(const void *kaddr, void *uaddr, size_t len, size_t *done); int copyin_proc(struct proc *p, const void *uaddr, void *kaddr, size_t len); int copyout_proc(struct proc *p, const void *kaddr, void *uaddr, size_t len); int ioctl_copyin(int ioctlflags, const void *src, void *dst, size_t len); int ioctl_copyout(int ioctlflags, const void *src, void *dst, size_t len); DESCRIPTION
The copy functions are designed to copy contiguous data from one address to another. All but copystr() copy data from user-space to kernel- space or vice-versa. The copy routines provide the following functionality: copyin() Copies len bytes of data from the user-space address uaddr in the current process to the kernel-space address kaddr. copyout() Copies len bytes of data from the kernel-space address kaddr to the user-space address uaddr in the current process. copystr() Copies a NUL-terminated string, at most len bytes long, from kernel-space address kfaddr to kernel-space address kdaddr. If the done argument is non-NULL, the number of bytes actually copied, including the terminating NUL, is returned in *done. copyinstr() Copies a NUL-terminated string, at most len bytes long, from user-space address uaddr in the current process to kernel-space address kaddr. If the done argument is non-NULL, the number of bytes actually copied, including the terminating NUL, is returned in *done. copyoutstr() Copies a NUL-terminated string, at most len bytes long, from kernel-space address kaddr to user-space address uaddr in the current process. If the done argument is non-NULL, the number of bytes actually copied, including the terminating NUL, is returned in *done. copyin_proc() Like copyin(), except it operates on the address space of the process p. copyout_proc() Like copyout(), except it operates on the address space of the process p. ioctl_copyin() Like copyin(), except it operates on kernel adresses when the FKIOCTL flag is passed in ioctlflags from the ioctl call. ioctl_copyout() Like copyout(), except it operates on kernel adresses when the FKIOCTL flag is passed in ioctlflags from the ioctl call. RETURN VALUES
The copy functions return 0 on success or EFAULT if a bad address is encountered. In addition, the copystr(), copyinstr(), and copyoutstr() functions return ENAMETOOLONG if the string is longer than len bytes. SEE ALSO
fetch(9), store(9) BSD
August 28, 2005 BSD
All times are GMT -4. The time now is 07:57 PM.
Unix & Linux Forums Content Copyright 1993-2022. All Rights Reserved.
Privacy Policy