How to generate a stack trace with in own kernel module [closed] - linux-kernel

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I would like to generate a stack trace report like one generated by kernel oops.
------------[ cut here ]------------
kernel BUG at /home/administrator/project/systech/bsp_tan/linux-.2.6/arch/arm/include/asm/dma-mapping.h:325!
Internal error: Oops - undefined instruction: 0 [#1] PREEMPT
Modules linked in:
CPU: 0 Not tainted (3.2.6 #67)
PC is at my_func+0x118/0x230
LR is at vprintk+0x3bc/0x440
Where it's defined and how I can trigger it with in my module.
EDIT 1
How to find the line number where the PC (program counter) was when this bug happened.
PC is at my_func + 0x118/0x230
What this means?
Thanks in advance.

this is in the following files:
lib/bug.c
kernel/panic.c

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Confusing, what is this inside the channel in Go Routines [closed]

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Program :
package main
import (
"fmt"
)
func main() {
ch := make(chan int)
fmt.Println(ch)
fmt.Println(0xc000062060)
}
Output :
0xc00009e000
824634122336
What does that output (824634122336) mean?
I think (0xc00009e000) is a starting address of an channel.
If (0xc00009e000 is address of channel)
Then please tell me what is this (824634122336)
else
Then please tell what are those outputs.
0xc00009e000 is a hexadecimal value of 824634122336. So 824634122336 not a value in the channel.
fmt.Println(0x10) //Output: 16
In software calculations, "0x" prefix adding to represent the hexadecimal numbers.
Refer this why-are-hexadecimal-numbers-prefixed-with-0x

Why should add a name before the statement in VHDL? [closed]

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ARCHITECTURE synthesis1 OF vending IS
TYPE statetype IS (Idle, Opt1, Opt2, Error);
SIGNAL currentstate, nextstate : statetype;
BEGIN
fsm1: PROCESS( buttons, currentstate ) -- Is necessary to give the PROCESS bl a name?
BEGIN
-- Process the input
END PROCESS;
END synthesis1;
Is necessary to give the Process a name? Why should I set the name?
No. It is not necessary. It is optional. However, sometimes it is useful to give a process (or other statement) a name, for example, to make your code easier to read.

Why snmpset cant save value? [closed]

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i'm using this commands for disable mikrotik interface:
user#host:~$ snmpget -v 2c -c public 192.168.0.10 1.3.6.1.2.1.2.2.1.7.3
iso.3.6.1.2.1.2.2.1.7.3 = INTEGER: 1
user#host:~$ snmpset -v 2c -c public 192.168.0.10 1.3.6.1.2.1.2.2.1.7.3 i 2
iso.3.6.1.2.1.2.2.1.7.3 = INTEGER: 2
user#host:~$ snmpget -v 2c -c public 192.168.0.10 1.3.6.1.2.1.2.2.1.7.3
iso.3.6.1.2.1.2.2.1.7.3 = INTEGER: 1
snmp have write-access,
where is problem?
Instead of 'public' you need to use the write community string of the target system. It's like a password, else anyone could change system parameters.

Creating beep sound in Windows [closed]

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I want to write a procedure that creates a beep sound on Windows, using assembly language.
How can I do that? Do you have any starting point idea?
In MS-DOS, which is what many assembly novices are targeting without even knowing it, outputting character ASCII 7 (BEL) via interrupt 21h, function AH=2 will do it:
mov ah, 2
mov dl, 7
int 21h
In Windows, call the MessageBeep() API function, passing 0xffffffff as the parameter. The function resides in User[32].dll; depending on your assembler, the sequence for importing an API function might vary.
If by "Windows" you mean "DOS executable running under Windows", which some people occasionally do, then back to int21h.

Understanding dmesg messages [closed]

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I am a newbie learning how to write Linux device drivers for USB devices. I want to understand the dmesg ouput
[ 6870.420077] usb 2-5: new low-speed USB device number 43 using ohci_hcd
[ 6870.500057] hub 2-0:1.0: unable to enumerate USB device on port 5
[ 6871.444057] usb 2-5: new low-speed USB device number 44 using ohci_hcd
[ 6871.524065] hub 2-0:1.0: unable to enumerate USB device on port 5
[ 6872.468089] usb 2-5: new low-speed USB device number 45 using ohci_hcd
[ 6872.548065] hub 2-0:1.0: unable to enumerate USB device on port 5
Could you direct me to some reading material explaining how to decipher these kernel messages?
dmesg - print or control the kernel ring buffer.
when dmesg command is issued, kernel ring buffer messages will be printed. There is no specific format used I guess.
Mostly whenever a new driver(or kernel code) is written, that particular module name is print first and corresponding message will be printed for differentiating our messages.
for example,
printk(KERN_ALERT "JayModule: Module loaded successfully.. ");
will print JayModule: Module loaded successfully.. in kernel ring buffer.
I guess numeric values given within [] is time.

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