Userspace interception of locally valid memory location

2013-03-10 Thread harish badrinath
Hello, Is it possible to intercept (both read and write) a locally valid address of a process and replace it with our own values (it is for a transparent distributed shared memory project). Regards, Harish Badrinath ___ Kernelnewbies mailing list

Re: Userspace interception of locally valid memory location

2013-03-10 Thread Valdis . Kletnieks
On Sun, 10 Mar 2013 19:27:52 +0530, harish badrinath said: Is it possible to intercept (both read and write) a locally valid address of a process and replace it with our own values (it is for a transparent distributed shared memory project). Go look at how gdb traces variables.

Re: Userspace interception of locally valid memory location

2013-03-10 Thread Valdis . Kletnieks
On Sun, 10 Mar 2013 19:27:52 +0530, harish badrinath said: Hello, Is it possible to intercept (both read and write) a locally valid address of a process and replace it with our own values (it is for a transparent distributed shared memory project). (Damn, hit send too soon) Go look at how

User space memory

2013-03-10 Thread Christoph Seitz
Hi all, I have some problems allocation Memory the right way and use it in my kernel module. I use a char device for reading and writing from/to a pcie dma card. Especially the read function makes me some headache. The user allocates some memory with posix_memalign and call the read function on

Re: 64bit MMIO access

2013-03-10 Thread Jagath Weerasinghe
Hi, readq and writeq do the job. On Thu, Feb 28, 2013 at 11:15 PM, valdis.kletni...@vt.edu wrote: On Thu, 28 Feb 2013 22:46:58 +0100, Jagath Weerasinghe said: What are the read/write kernel functions to access 64bit MMIO addresses? Are there similar functions like readl() and writel() for

Re: 64bit MMIO access

2013-03-10 Thread Valdis . Kletnieks
On Sun, 10 Mar 2013 20:35:37 +0100, Jagath Weerasinghe said: readq and writeq do the job. Please double-check how those are implemented on your architecture. I seem to remember that on some systems, readq and writeq may not be atomic and may become two bus cycles. And some hardware cares about

Re: 64bit MMIO access

2013-03-10 Thread Valdis . Kletnieks
On Sun, 10 Mar 2013 20:35:37 +0100, Jagath Weerasinghe said: Hi, readq and writeq do the job. (hit send too soon) Also, the read/write [bwlq] functions refer to the width of the *data*, not the address pgpRFJDCHascC.pgp Description: PGP signature

location of inbuilt system call implementation

2013-03-10 Thread Niroj Pokhrel
Hi All, I am newbies to Linux and am going through system call in kernel-3.4. I just wanted to check how sys_read, sys_write or other system calls work but I was searching for the implementation but couldn't find it. I found that : System Call are added in /arch/x86/syscalls/syscall_32(or64).tbl.