is a process of finding and reducing the number of bugs, or defects, in a computer program, thus making it behave as expected
0
votes
1answer
11 views
Generic debugging / logging / tracing filesystem directory & file access? [duplicate]
This is my particular problem: I'm trying to set up git on a server, for which I'm doing a test on a locally installed apache on Ubuntu 14.04; for instance, I can do git clone fine over HTTP, but git ...
1
vote
2answers
41 views
Who is stealing my pids?
I noticed that my Debian Jessie system is using many pids, even when the system is (should be) largely idle. The following shows that more or less 270 pids are used per 10s, while the number of active ...
1
vote
0answers
15 views
How to enable kernel pstore?
I'm trying to enable the kernel persistent storage (pstore) in order to help debug a module which malfunctions and freezes my laptop on suspend, but I'm having difficulties doing so.
My kernel ...
1
vote
0answers
16 views
How to let kernel not run the printk with KERN_DEBUG
I noticed that kernel has different console levels for the printk.
I also noticed this post [1].
I understand that we can change the /proc/sys/kernel/printk to change the printk level for the ...
3
votes
2answers
37 views
How can I activate extra-verbose mode (debugging mode) during Debian boot?
How do I activate extra verbosity during boot, on Debian? I removed the quiet parameter and tried to add debug but it didn't help.
My problem is that my keyboard takes 2-3 min to activate so it ...
1
vote
2answers
23 views
Making sense of Time in dmesg
I know the time in dmesg is the time since boot. But my specific question is this time is calculated at the start or end of the process mentioned in the line?
Why this is important?
take this ...
4
votes
2answers
134 views
Understanding wpa_supplicant
TL;DR. I need help getting to the bottom of:
why there are errors related to ioctl when using wext driver,
why I'm not able to use nl80211 driver.
When running wpa_supplicant I get weird errors ...
0
votes
1answer
18 views
Storing PHP output issued by crontab
I have a PHP file that is suppose to send one email per day scheduled by crontab. Here is my crontab:
45 23 * * * php /var/www/html/linus/class/runnable/dailyStaffReport.php
I noticed that it's not ...
1
vote
2answers
28 views
Debugging “unable to connect to sendmail server”
In a corporate environment, we have a mail server which has only ports 25/tcp and 587/tcp available.
When we use Perl Scripts (using HTML::Mail) to send hundreds of legitimate mails, it occasional ...
3
votes
1answer
35 views
How to dump the dmesg AKA Kernel logs to a single .txt file from the kernel boot?
I am trying to understand the SATA Host-Device Communication and for that I have put a lot of debug messages in the kernel driver code.
Now messages are in such a huge amount that I am not able to see ...
2
votes
2answers
128 views
Debugging a kernel shut down?
I'm on Linux 4.2.0, the Ubuntu Wily HWE kernel for Ubuntu 14.04 (which is what I'm running).
There's a nasty bug on MacBook 11,4 and 11,5 models where the laptops won't actually ever shut off, they ...
0
votes
0answers
23 views
How to debug a bash script in a qemu-arm chroot
I'm running a debian debootstrap script which creates an arm system. However, the script fails at some point and the error message does not really help. So I'll have to do some more debugging which is ...
0
votes
1answer
25 views
Why is echo not working for mt valgrind command?
So I have my makefile working great, except that It doesn't create the valgrind.out file and I don't know why. So the console succesfully prints out that my executable file line is created but not ...
2
votes
1answer
69 views
Inline debug (xtrace) in scripts
Is there a way to force enable or disable debug (xtrace) per command line in scripts ?
In Windows Shell ("ms-dos") is an "@" which can prefix a command line, disabling that line to be showed if the ...
0
votes
0answers
17 views
Does Manjaro Linux have a debug packages
One of my biggest frustrations with Arch Linux is the need to recompile half my OS every few weeks in order to provide meaningful bug reports to upstream projects. Most other distributions provide ...
1
vote
1answer
532 views
“rcu_preempt detected stalls on CPUs / tasks” message appears to continue
My board continues to display the message below.
The terminal does not have any input.
What is it with the following message, which I know? (T, g, c, q ...)
What is the cause of this phenomenon?
...
1
vote
0answers
132 views
Linux Kernel module Remote Debugging with GDB + KGDB, Remote 'g' packet reply is too long
I am trying to remotely debug Linux Kernel and I am having issues.
My setup:
Target machine with Ubnutu Linux with my custom kernel 4.3 which I built with debugging information and KGDB.
...
0
votes
1answer
43 views
Debugging: OwnCloud horribly slow
I am trying to figure out why my OwnCloud installation stalls of 10s of seconds before it runs again for 10s of seconds normally.
What kind of debugging can I enable on OwnCloud (server+client), so I ...
0
votes
0answers
34 views
printk does not prints in terminal
I inserted some printk in kernel 3.15.1 functions such as theese:
in fs/read_write.c in function read():
printk("Ata: Im in fs/read_write.c and in function read");
in same file in function ...
0
votes
1answer
70 views
Syntax error: Unterminated quoted string. Cannot find error
I'm writing a script to parse a larger file into usable data. I will attach the script below. The script was not running as I wanted and I thought it might have been the if/then statement I used, but ...
0
votes
0answers
40 views
OpenVPN Connection without disabling Internet debugging
I've recently configured OpenVPN on my server (CentOS 7) and been configuring it for hours now and everything seems to work fine except that when I connect using a client machine I cannot access the ...
1
vote
1answer
46 views
After my system crashed and I run crash, but I get the following error: not a supported file format
My system crashed and even though I haven't been able to know what caused the crash after going through the usual logs: messages, dmesg, secure, etc. There's nothing valuable I have seen on them so I ...
2
votes
2answers
628 views
Where is vagrant's log file?
I am trying to debug a vagrant- or VirtualBox related problem (see taiga-vagrant fails to provide a working taiga environment #21).
The command VAGRANT_LOG=debug vagrant up --debug prints out plenty ...
6
votes
2answers
76 views
xtrace equivalent in the fish shell
Is there an equivalent of POSIX shells' set -x or set -o xtrace that cause the shell to display the commands being run in the fish shell?
0
votes
0answers
19 views
Breakpoint in dynamically-linked libraries in Linux
Suppose you debug a Linux application and put a break-point into a function defined by a dynamically-linked library used by the application. Will that break-point stop any other application that makes ...
0
votes
0answers
41 views
Cannot telnet to Postgresql Forwarded Port
I'm trying to portforward a PostgreSQL port using my DLINK ADSL Router.
I have the following IP addresses.
Public Internet IP 197.321.321.32
PostgreSQL 192.123.123.12:5432 (Port To ...
0
votes
0answers
40 views
How can I display \n as new lines in multitail?
I am using multitail to monitor logs while I program. I really like this tool. However, it is hard to use it to view object output in a php error log because new line characters \n are not processed. ...
0
votes
1answer
38 views
SystemTap simple demo fails - Ubuntu 14.04
Started learning SystemTap using RedHat's manual.
Here is the example I'm trying to run.
While executing stap open.stp I got the error:
[root@ror6ax ~]# stap open.stp
semantic error: while resolving ...
-1
votes
1answer
100 views
Debug an open-source and be confronted with some troubles [closed]
Here is main script . I run it and get some errors like this :
╭─frankwang@ubuntu ~/ion-open-source
╰─➤ ./ionadmin ...
2
votes
2answers
119 views
shell script with interesting bug
I've found such behavior of bash GNU bash, version 4.3.30(1)-release (x86_64-pc-linux-gnu) and even latest ( How to get version of dash? ) dash on Debian.
Bug as is:
/bin/echo "Silent Err ...
2
votes
2answers
80 views
Why does df on a specific mount iterate over all mounts?
When running df /nfs/mount/point, I expect that it will be faster than df | grep /nfs/mount/point, because it will not stat all other mount points.
But strace shows that stat is executed all NFS ...
0
votes
0answers
1k views
Kernel panic : Kernel offset disabled
I was trying to install the linux-next kernel in my system with the following steps.
Copied the existing configuration file from /boot to the root of source directory
Updated the .config file with ...
0
votes
0answers
53 views
Attempting to use LogLevel debug to investigate server issue
I am currently running a WordPress Multisite installation with a number of websites active. I have started getting large volumes of the following error message in my error log:
Request exceeded the ...
2
votes
0answers
49 views
Network debugging: Sudden rise in packet loss and latency
My laptop sees a sudden rise in packet loss and latency (from 0.0%, 1ms to 70%, 2000ms).
It remains even after resuming from suspend-to-ram.
It remains after:
sudo killall wpa_supplicant
sudo ...
8
votes
1answer
118 views
Tool to trace library calls in Linux/ARM
I am searching for a tool that allows to trace calls to functions in shared libraries in Linux/ARM. Basically, I want to be able to specify a command line and let this tool produce a record of called ...
1
vote
2answers
78 views
How can I disable xtrace and preserve my exit code
I'm trying to figure out a good way to disable xtrace before leaving a script. These are all being executed by Wercker, a continuous integration and deployment SaaS.
A previous script of mine has run ...
0
votes
0answers
136 views
Can't install additional debug infos in the CentOS 6.7
I am attempting to debug coredump of the some application on the latest CentOS 6.7 and gdb gives me hints that some debug infos are missing, for example:
Missing separate debuginfo for ...
3
votes
1answer
35 views
Is it possible to compile individual software from the FreeBSD source tree?
I wonder if it is possible to compile individual software packages from FreeBSD source tree without compiling the whole kernel and world....Say,for example ex , which is included in the nvi (new vi) ...
0
votes
1answer
59 views
Is there a GUI debugger for csh script?
I have read another question in UNIX & LINUX stack exchange. The GUI provided in that question can be used to bebug *.sh file. How about to debug *.csh file? What other plugins for eclipse can I ...
0
votes
1answer
86 views
Uninstalling packages installed by debuginfo-install
How do I delete debug packages that are installed by debuginfo-install?
When I search for them via sudo yum list installed none of the installed packages are listed, even when I enabled the debuginfo ...
4
votes
1answer
1k views
How to passively capture from Unix domain sockets (AF_UNIX socket monitoring)?
TCP/IP and UDP captures can be made using tcpdump/dumpcap and produces a pcap/pcapng file which can be fed to Wireshark for further analysis. Does a similar tool exist for named Unix domain sockets? ...
2
votes
1answer
223 views
What is Linux native debugging symbols format?
GCC documentation says that the -g option produces debugging information in the operating system's native format (stabs, COFF, XCOFF, or DWARF 2).
So, what is Linux native debugging symbols format? ...
1
vote
2answers
505 views
How to call in a kernel level function in user space [closed]
I've developed some helper functions in the kernel. They're called by other functions in the kernel. Currently, they make my custom kernel panic :(
For now (i.e. debugging), I made them as a passive ...
2
votes
1answer
345 views
How to debug a kernel panic on boot with archiso?
I have an iMac mid 2011 running OSX and I am trying to install Arch Linux following this guide. I successfully set up a dual boot last year following a similar procedure but now I can't even start ...
2
votes
0answers
34 views
Significance of Linux kernel's default_console_loglevel
What is the significance of default_console_loglevel in Linux? Commonly I see it described as the default value of console_loglevel. However, what that means I haven't seen explained anywhere.
...
0
votes
0answers
513 views
How to change the console_loglevel in linux?
I read at multiple places (e.g. here http://elinux.org/Debugging_by_printing), that you can change the console log level by echoing an integer to /proc/sys/kernel/printk. If that worked shouldn't the ...
0
votes
1answer
35 views
Linux server as a target for my C code [closed]
How to use a linux server as a target for my C code written on a different (Windows) machine. Including step by step debugging and etc... All that with Eclipse Env.
1
vote
2answers
227 views
viewing printf after pipe (or subshell?)
Ok, this is hard to distill to a single question because it really depends on how I'm going to troubleshoot it.
The following script is meant to pipe mount.cifs commands to a while loop that enters ...
1
vote
0answers
146 views
ath0 wi-fi connection breaks
Can't hold wi-fi connection in hostapd mode. Sometimes it's good, sometimes not, yesterday all day wi-fi works, today no chance even to connect.
% more /etc/rc.conf
wlans_ath0="wlan0"
...
0
votes
1answer
161 views
What is the impact on system performance when kernel debug info is enabled?
In order to debug kernel or use tools like stap (https://en.wikipedia.org/wiki/SystemTap) kernel must be compiled with full debugging information included - namely option CONFIG_DEBUG_INFO has to be ...
