HELP is urgently required,
I run on SCO Unix 3 and this is the panic message that I get every time that I reboot 10U
k_trap - kernel mode trap type 0x0000000E
I have checked the swap already having the following results:
#swap -l
path dev swaplo blocks free... (3 Replies)
hi,
I am trying to install sco openserver 5.0.4 on an old system. However, l was not able to proceed after putting the bootstr
l have this panic message of
PANIC: K_trap - kernel mode trap tupe 0x00000006
will someone kindly help to decode this error
kayode (1 Reply)
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)
Hi all i have queastion. Can anybody pease help me
what is user mode and kernel mode and the term "De-mountable volumes" means?
Thanks
Palash (2 Replies)
Hello,
Can someone pls help me with some statistical calculation in awk
In excel there is a statistical function called "Mode".
How Mode works:
MODE returns the most frequently occurring, or repetitive, value in array or range.
Eg if we have 5 numbers in 5 different columns... (12 Replies)
Hi, i'm another question:
I'm a directory /usr/data on my server sco unix 5.0.5:
# du /usr/data
4386948 /usr/data
I'm tried to connect to ftp directory /usr/data to this server and:
PANIC: k_trap - Kernel mode trap type 0x0000000E
Cannot dump 262040 pages to dumpdev hd(1/41):space... (3 Replies)
Hi everyone. I would like to hook a system function (gettimeofday) to modify it. I guess I'll need kernel mode to do that. By the way, how could I do it (c++ or c)?
I want to modify that function for one process which I know the PID. So I need to return my own value for that PID and real value... (29 Replies)
Hi,all:
I run my program which consists of one kernel module and one user mode process on a dual core server. The problem here is the kernel module consumes 100% of one core while the user mode process only consumes 10% of the other core, is there any solution that I can assign some computing... (1 Reply)
Hi,
I am new to the linux kernel development area. I want to know what is the difference between kernel mode stack and user mode stack? Does each process has a user mode stack and a kernel mode stack?? Or Each process has a user mode stack and there is only one kernel mode stack that is shared by... (4 Replies)
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
LEARN ABOUT LINUX
uiomove
UIO(9) BSD Kernel Developer's Manual UIO(9)NAME
uio, uiomove -- device driver I/O routines
SYNOPSIS
#include <sys/types.h>
#include <sys/uio.h>
struct uio {
struct iovec *uio_iov; /* scatter/gather list */
int uio_iovcnt; /* length of scatter/gather list */
off_t uio_offset; /* offset in target object */
ssize_t uio_resid; /* remaining bytes to copy */
enum uio_seg uio_segflg; /* address space */
enum uio_rw uio_rw; /* operation */
struct thread *uio_td; /* owner */
};
int
uiomove(void *buf, int howmuch, struct uio *uiop);
DESCRIPTION
The function uiomove() is used to handle transfer of data between buffers and I/O vectors that might possibly also cross the user/kernel
space boundary.
As a result of any read(2), write(2), readv(2), or writev(2) system call that is being passed to a character-device driver, the appropriate
driver d_read or d_write entry will be called with a pointer to a struct uio being passed. The transfer request is encoded in this struc-
ture. The driver itself should use uiomove() to get at the data in this structure.
The fields in the uio structure are:
uio_iov The array of I/O vectors to be processed. In the case of scatter/gather I/O, this will be more than one vector.
uio_iovcnt The number of I/O vectors present.
uio_offset The offset into the device.
uio_resid The remaining number of bytes to process, updated after transfer.
uio_segflg One of the following flags:
UIO_USERSPACE The I/O vector points into a process's address space.
UIO_SYSSPACE The I/O vector points into the kernel address space.
UIO_NOCOPY Do not copy, already in object.
uio_rw The direction of the desired transfer, either UIO_READ, or UIO_WRITE.
uio_td The pointer to a struct thread for the associated thread; used if uio_segflg indicates that the transfer is to be made from/to a
process's address space.
RETURN VALUES
On success uiomove() will return 0, on error it will return an appropriate errno.
ERRORS
uiomove() will fail and return the following error code if:
[EFAULT] The invoked copyin(9) or copyout(9) returned EFAULT
EXAMPLES
The idea is that the driver maintains a private buffer for its data, and processes the request in chunks of maximal the size of this buffer.
Note that the buffer handling below is very simplified and will not work (the buffer pointer is not being advanced in case of a partial
read), it is just here to demonstrate the uio handling.
/* MIN() can be found there: */
#include <sys/param.h>
#define BUFSIZE 512
static char buffer[BUFSIZE];
static int data_available; /* amount of data that can be read */
static int
fooread(dev_t dev, struct uio *uio, int flag)
{
int rv, amnt;
rv = 0;
while (uio->uio_resid > 0) {
if (data_available > 0) {
amnt = MIN(uio->uio_resid, data_available);
rv = uiomove(buffer, amnt, uio);
if (rv != 0)
break;
data_available -= amnt;
} else
tsleep(...); /* wait for a better time */
}
if (rv != 0) {
/* do error cleanup here */
}
return (rv);
}
SEE ALSO read(2), readv(2), write(2), writev(2), copyin(9), copyout(9), sleep(9)HISTORY
The uio mechanism appeared in some early version of UNIX.
AUTHORS
This manual page was written by Jorg Wunsch.
BSD March 21, 2010 BSD