How can a running C-program detect if it is running in "chroot" on illumos/solaris?
There is a Debian utility [1] which uses some tricks on linux, freebsd, hurd.
How to do it on illumos/solaris?
[1] http://anonscm.debian.org/gitweb/?p=users/clint/debianutils.git;a=blob;f=ischroot.c;h=bed67f9f655d26906e3d65fd290698dce5402a89;hb=HEAD
There's this thread on comp.unix.solaris which details various methods to find out whether Solaris runs inside a zone (container / chroot-on-lots-of-steroids) or a VM. Particularly extensive is the list in this posting (seems to have come from this blog post. I'll recreate some of the items relating to zones here - those that are available to non-root users.
The /usr/bin/zonename command tells you something different than "global"
The Solaris kernel "process" is called sched in a non-zoned (or inside the "global" / admin zone) environment but zsched inside a zone.
The Solaris prstat command (similar to top on other UN*Xes) has -z / -Z command line options to restrict reporting to specific zones (-z) or give statistics for all zones (-Z); inside a zone, these options don't work / only show you the zone you're running inside.
Hope that helps a little.
I used this way:
#elif defined (__sun__)
/* Similar to Linux
* XXX: check zone?
* XXX: illumos kernel automatically mounts /proc on boot
*/
static int ischroot()
{
struct stat st1, st2;
if (stat("/", &st1))
return 2;
if (stat("/proc/1/root", &st2))
return 2;
if ((st1.st_dev == st2.st_dev) && (st1.st_ino == st2.st_ino))
return 1;
return 0;
}
#else
Related
I "borrowed" the LPINFOX REXX program from this url: [http://www.longpelaexpertise.com/toolsLPinfoX.php]
When I run it "directly" (EX 'hlq.EXEC(LPINFOX)') it runs fine:
------------------------------------------------------
LPInfo: Information for z/OS ssssssss as of 18 Mar 2021
------------------------------------------------------
z/OS version: 02.04
Sysplex name: LOCAL
JES: JES2 z/OS 2.4 (Node nnnn)
Security Software: RACF
CEC: 3907-Z02 (IBM Z z14 ZR1)
CEC Serial: ssssss
CEC Capacity mmmm MSU
LPAR name: llll
LPAR Capacity mmm`enter code here` MSU
Not running under a z/VM image
But, if I insert the call into another exec, I get a RC -2 from the address LINKPGM call:
------------------------------------------------------
LPInfo: Information for z/OS ssssssss as of 18 Mar 2021
------------------------------------------------------
z/OS version: 02.04
Sysplex name: LOCAL
JES: JES2 z/OS 2.4 (Node N1)
Security Software: RACF
79 - Address Linkpgm 'IWMQVS QVS_Out'
+++ RC(-2) +++
CEC: -
CEC Serial:
LPAR name:
Not running under a z/VM image
I'm sure this has to do with the second level of REXX program running, but what can I do about the error (besides queueing up the EXecution of the second REXX)? I'm also stumped on where this RC is documented...my Google search for "REXX ADDRESS RC -2" comes up short.
Thanks,
Scott
PS(1), per answer from #phunsoft:
Interesting. I didn't copy the code to my other REXX. I invoked LPINFOX from within another rexx: I have a hlq.LOGIN.EXEC that has a "EX 'hlq.LPINFOX.EXEC" statement within it. When I reduce the first exec to "TEST1" (follows), it fails the same way:
/* REXX */
"EXECUTIL TS"
"EX 'FAGEN.LPINFOX.EXEC'"
exit 0
When I run TEST1, this is the output from the EXECUTIL from around the IWMQVS call:
When I run LPINFOX.EXEC directly from the command line, the output is the same, except the address LINKPGM IWMQVS works fine:
I can only surmise that there is some environmental difference when I run the exec "standalone" vs. when I run the exec from another exec.
PS(2), per question about replacing IWMQVS with IEFBR14 from phunsoft:
Changing the program to IEFBR14 doesn't change the result, RC=-2.
LINKPGM is a TSO/E REXX host command environment, so you need to search in the TSO/E REXX Reference. From that book:
Additionally, for the LINKMVS, ATTCHMVS, LINKPGM, and ATTCHPGM
environments, the return code set in RC may be -2, which indicates that processing
of the variables was not successful. Variable processing may have been
unsuccessful because the host command environment could not:
o Perform variable substitution before linking to or attaching the program
o Update the variables after the program completed
Difficult to say what th problem is without seeing the code.
You may want to use REXX's trace feature to debug. Do you run this REXX from TSO/E foreground? If so, you might run TSO EXECUTIL TS just before you start that REXX. It will then run as if trace ?i wa specified as the fist line of the code.
I've had look at the LPINFOX EXEC and saw that variable QVS_Out is set as follows just before linking to IWMQVS:
QVS_Outlen = 500 /* Output area length */
QVS_Outlenx = Right(x2c(d2x(QVS_Outlen)),4,d2c(0))
/* Get length as fullword */
QVS_Out = QVS_Outlenx || Copies('00'X,QVS_Outlen-4)
Did you do this also when you copied the call to your other REXX?
I am on linux ubuntu and target is a PIC18F47J53.
I basically want to program the chip and then let it run, using command lines and using pickit4.
using ipecmd (from mplab x ide v5.45), this is my command:
/opt/microchip/mplabx/v5.45/sys/java/zulu8.40.0.25-ca-fx-jre8.0.222-linux_x64/bin/java -jar /opt/microchip/mplabx/v5.45/mplab_platform/mplab_ipe/ipecmd.jar -TPPK4 /P18F47J53 -M -F"/path_to_myfile.hex" -W
This is my output
DFP Version Used : PIC18F-J_DFP,1.4.41,Microchip
*****************************************************
Connecting to MPLAB PICkit 4...
Currently loaded versions:
Application version............00.06.66
Boot version...................01.00.00
Script version.................00.04.17
Script build number............db473af2f4
Tool pack version .............1.6.961
PICkit 4 is supplying power to the target (3.25 volts).
Target device PIC18F47J53 found.
Device Revision Id = 0x1
*****************************************************
Calculating memory ranges for operation...
Erasing...
The following memory area(s) will be programmed:
program memory: start address = 0x0, end address = 0x3ff
program memory: start address = 0x1fc00, end address = 0x1fff7
configuration memory
Programming/Verify complete
Program Report
30-Jan-2021, 12:54:41
Device Type:PIC18F47J53
Program Succeeded.
Operation Succeeded
All good, and takes about 12 seconds, however, after that the pickit4 turns off the power target, and the pickit LED is BLUE (I guess state "ready")
The main question is how can I let the pickit4 powering the boards? any specific parameter? (I cannot find on the readme.html)
If I use MPLAB X IPE GUI to program, the programming is much quicker (3 or 4 seconds), the pickit LED is YELLOW and the target is left powered on. (I selected "release from reset")
I have tried to get the log out with as many details as possible, but I cannot see the commands sent to the pickit4.
Any idea? thanks
I realize that it's been a while since you asked, but i put the answer here for anyone who needs it. Add -OL to your command line options.
In a device driver source in the Linux tree, I saw dev_dbg(...) and dev_err(...), where do I find the logged message?
One reference suggest to add #define DEBUG . The other reference involves dynamic debug and debugfs, and I got lost.
dev_dbg() expands to dynamic_dev_dbg(), dev_printk(), or no-op depending on the compilation flags.
#if defined(CONFIG_DYNAMIC_DEBUG)
#define dev_dbg(dev, format, ...) \
do { \
dynamic_dev_dbg(dev, format, ##__VA_ARGS__); \
} while (0)
#elif defined(DEBUG)
#define dev_dbg(dev, format, arg...) \
dev_printk(KERN_DEBUG, dev, format, ##arg)
#else
#define dev_dbg(dev, format, arg...) \
({ \
if (0) \
dev_printk(KERN_DEBUG, dev, format, ##arg); \
})
#endif
dynamic_dev_dbg() and dev_printk() call dev_printk_emit() which calls vprintk_emit().
This very same function is called in a normal mode when you just do a printk(). Just note here, that the rest functions like dev_err() will end up in the same function.
Thus, obviously, the buffer is all the same, i.e. kernel intrenal buffer.
The logged message at the end is printed to
Current console if kernel loglevel value (can be changed via kernel command line or via procfs) is high enough for certain message, here KERN_DEBUG.
Internal buffer which can be read by running dmesg command.
Note, data in 2 is kept as long as there still room in the buffer. Since it's limited and circular, newer data preempts old one.
Additional information how to enable Dynamic Debug.
First of all, be sure you have CONFIG_DYNAMIC_DEBUG=y in the kernel configuration.
Assume we would like to enable all debug prints in the built-in module with name 8250. To achieve that we simple add to the kernel command line the following 8250.dyndbg=+p.
If the same driver is compiled as loadable module we may either add options 8250 dyndbg to the modprobe configuration or to the shell command line when do it manually, like modprobe 8250 dyndbg.
More details are described in the Dynamic Debug documentation.
The "How certain debug prints are automatically enabled in linux kernel?" raises the question why some debug prints are automatically enabled and how DEBUG affects that when CONFIG_DYNAMIC_DEBUG=y. The answer is lying in the dynamic_debug.h and since it's used during compilation the _DPRINTK_FLAGS_DEFAULT defines the certain message appearence.
#if defined DEBUG
#define _DPRINTK_FLAGS_DEFAULT _DPRINTK_FLAGS_PRINT
#else
#define _DPRINTK_FLAGS_DEFAULT 0
#endif
you can find dev_err(...) in kernel messages. As the name implies, dev_err(...) messages are error messages, so they will definitely be printed if the execution comes to that point. dev_dbg(...) are debug messages which are more generously used in the kernel driver code and they are not printed by default. So everything you have read about dynamic_debugging comes into play with dev_dbg(...).
There are several pre-conditions to have dynamic debugging working, below 1. and 2. are general preconditions for dynamic debugging. 3. and later are for your particular driver/module/subsystem and can be .
Dynamic debugging support has to be in your kernel config CONFIG_DYNAMIC_DEBUG=y. You may check if it is the case zgrep DYNAMIC_DEBUG /proc/config.gz
debugfs has to be mounted. You can check with sudo mount | grep debugfs and if not existing, you can mount with sudo mount -t debugfs /sys/kernel/debug
refer to dynamic_debugging and enable the particular file/function/line you are interested
Installer is installed typically using GUI or console, we need unattended installation capability as well. Running the installer like this (in Linux):
myapp -q -c -varfile myfile.var
Installer installs the software successfully. Problem is it ignores some variables (not all variables). It doesn't read values for zServerPort$Long and zShutdownPort$Long variables and instead applies the default values configured in application.
Varfile is provided below
#install4j response file for Sw 4.6
#Mon Aug 11 19:55:46 PDT 2014
sys.adminRights$Boolean=true
choiceIsLicenseSelected=true
zDBUserName=user
zLaunchDesktopPostInstall$Boolean=false
zDBPassWord=password
sys.languageId=en
sys.installationDir=/opt/mydir
zServerPort$Long=85
zLicenseFilePath=/home/mydir/Desktop/license.lic
zMysqlPath=/usr/bin/mysql
zMysqlCnf=/etc/mysql/my.cnf
zDbPort$Long=3306
choiceInstallDir=/opt/mydir
zShutdownPort$Long=8015
zServerPort, zShutdownPort, choiceInstallDir, zMysqlPath are all installer variables. Reordering the variables didn't work either. Is the problem due to data type being Long ?
Is there a way to pass the values of these two variables zServerPort, zShutdownPort in some other way ?
Other idea am thinking is whether if the installer can know that it is being run in unattended mode and read these variables from command line ?
Most likely, the defaults are applied with a code snippet and not through the initial values of form components.
In those code snippets (i.e. in a "Run script" action"), you have to check whether the value is already defined or not. For example:
if (context.getVariable("variableName") != null) {
context.setVariable("variableName"), 100L);
}
I am using the Debian wheezy filesystem with Robert Nelson's latest kernel.
I want to disable the heartbeat led using a device tree overlay.
I understand there are easier ways of doing this but I am only interested in answers using overlays to disable the heartbeat led.
One way I can achieve this is by changing the gpio-leds,led0 leaf in am335x-boneblack.dts
from:
linux,default-trigger = "heartbeat";
to
linux,default-trigger = "none";
then compiling the device tree and rebooting.
However if I try to implement the same thing using the following overlay the heartbeat led continues to flash after I successfully apply the overlay with echo > $SLOTS.
What am I doing wrong?
/dts-v1/;
/plugin/;
/
{
compatible = "ti,beaglebone", "ti,beaglebone-black";
part-number = "pru";
version = "00A0";
fragment#0
{
target = <&ocp>;
__overlay__
{
gpio-leds
{
compatible = "gpio-leds";
pinctrl-names = "default";
pinctrl-0 = <0x3>;
led0
{
label = "beaglebone:green:usr0";
gpios = <0x5 0x15 0x0>;
linux,default-trigger = "none";
default-state = "off";
};
};
};
};
};
There's a systemd service, leds.service, that overrides the device tree settings for this one led (who knows why).
To see the status of the service, run
root#beaglebone:~# systemctl status leds.service
which gives the output
leds.service - Angstrom LED config
Loaded: loaded (/lib/systemd/system/leds.service; enabled)
Active: active (exited) since Sat 2000-01-01 18:33:24 UTC; 13 years 7 months ago
Process: 125 ExecStart=/usr/bin/led-config start (code=exited, status=0/SUCCESS)
CGroup: name=systemd:/system/leds.service
By looking at the "Loaded" field you can see that the service script is located at /lib/systemd/system/leds.service, and the "Process" field says the this service runs the command "/usr/bin/led-config start".
Looking at this file "/usr/bin/led-config" you'll see that it's a shell script that loads defaults from the file "/etc/default/leds":
#file format: name trigger
beaglebone::usr0 heartbeat
So, you can leave the device tree file alone and set the defaults here, or disable this service with
systemctl disable leds.service
To disable the heartbeat with an overlay is very inefficient in my opinion! How about instead try typing in the bash command: "echo none > /sys/devices/ocp.3/gpio-leds.8/beaglebone\:green\:usr0/trigger" and then to turn them back on 'echo "heartbeat" > trigger' (check the file path first) - tested on Debian Wheezy A5A