Difference in values of addresses in System.map and /proc/kallsyms

Hi All. My system is ajay@latitude-3480:~$ uname -a Linux latitude-3480 4.13.0-38-generic #43~16.04.1-Ubuntu SMP Wed Mar 14 17:48:43 UTC 2018 x86_64 x86_64 x86_64 GNU/Linux When I see the address for a symbol, say linux_banner, in /boot/System.map-4.13.0-38-generic, it shows 81e00120 R

Query on how WWAN and Modem interact

Hi All. I am sorry upfront if this might seem like a stupid question. I am wanting to have some insight on how a modem plugs into the linux-kernel at architecture level. First a bit of history. I have prior experience of using an onboard-modem on a ubuntu, via support from modem-manager. There, a

Re: [Cubieboard-2] Booting up stuck at runlevel-2

, Ajay On Sat, Apr 28, 2018 at 9:35 AM, Ajay Garg wrote: > Hi All. > > After a lot of hit-and-trials, I have managed to get some bootup. > Unfortunately, not able to get a login-prompt. > > Following have been done : > > > == u-boot == > > u-boot has been comp

[Cubieboard-2] Booting up stuck at runlevel-2

Hi All. After a lot of hit-and-trials, I have managed to get some bootup. Unfortunately, not able to get a login-prompt. Following have been done : == u-boot == u-boot has been compiled using bleeding-edge mainline (ec5c4a8fd64a178a4d159917cda0aa176e5a9be5), via : * make Cubieboard2_defconfig

Is it an error to have two instances of "reboot" running at the same time?

-- Regards, Ajay

Multiple invocations of cron-job AT THE SAME MINUTE on Raspbian

Hi All. I have a raspbian-pi-3, and following is the first-level information :: uname -a Linux raspberrypi 4.4.11-v7+ #888 SMP Mon May 23 20:10:33 BST 2016 armv7l GNU/Linux Following is the script that is run by

Seeking recommendation on whether a bahviour is right/wrong

Hi All. I have been trying to debug a strange issue occurring on a "mostly mainline"-linux-kernel, running on a proprietary embedded-platform. I still haven't been able to zero-on the issue with 100% confirmation, but I think the following might be happening :: a) A C-user-application is running

Re: Is kernel-FD-auto-close exactly equal to explicit-FD-close?

nt to calling explicit "close()" call on the serial-port-FD? Thanks and Regards, Ajay On Tue, Aug 16, 2016 at 5:29 PM, Ajay Garg wrote: > Hi All. > > We have deployed a simple C-application on an embedded-platform > running Linux, and we spuriously observe file-corruption.

Is kernel-FD-auto-close exactly equal to explicit-FD-close?

Hi All. We have deployed a simple C-application on an embedded-platform running Linux, and we spuriously observe file-corruption. In particular, there is an all-important "config" file, and some of its lines are lost spuriously. Now, our application opens quite a few files on the file-systems, an

Re: Architectural-Queries on integrating Sierra-MC8090 with Linux

CCing NM and MM guys. On Thu, Aug 11, 2016 at 2:23 PM, Ajay Garg wrote: > Hi All. > > Have posted the question on Sierra-forums > https://forum.sierrawireless.com/viewtopic.php?f=117&t=9898 > Posting it here as well, as the activity there is relatively low, and > this i

Architectural-Queries on integrating Sierra-MC8090 with Linux

Hi All. Have posted the question on Sierra-forums https://forum.sierrawireless.com/viewtopic.php?f=117&t=9898 Posting it here as well, as the activity there is relatively low, and this is where all the kernel-guys hand :) I am using a Ubuntu interfaced with a Sierra-MC8090 module. Right now MC8

Crash in Modem-Manager on Ubuntu

Hi All. I am using Ubuntu, and achieve the following crash when trying to connect to a Mobile-Broadband connection :: Last few-logs :: ModemManager[11586]: Modem /org/freedesktop/ModemManager1/Mo

Re: Is it ok if ModemManager process is killed AFTER network-interface is brought up and IP-Address assigned?

Ok Greg :) On Tue, Aug 9, 2016 at 1:44 PM, Greg KH wrote: > On Tue, Aug 09, 2016 at 12:48:12PM +0530, Ajay Garg wrote: >> Hi All. >> >> We are using Sierra's USB-to-WWAN driver on Ubuntu-14 for Sierra's >> MC8090 modem, and we have a requirement wherein w

Is it ok if ModemManager process is killed AFTER network-interface is brought up and IP-Address assigned?

Hi All. We are using Sierra's USB-to-WWAN driver on Ubuntu-14 for Sierra's MC8090 modem, and we have a requirement wherein we need to have access to the modem-serial-port (from our user-application that is). Right now, we see that /usr/sbin/ModemManager is always connected to /dev/ttyUSB3 (which

Socket-Option in POSIX-sockets, to allow traffic via proxy

Hi All. Surprisingly, I could not find this on google :-\ We are trying to use vanilla POSIX-socket-APIs, but we are unable to connect if the URL is on the other side of the proxy. Is there a socket-option wherein this would be allowed? I will be grateful for any pointers. Thanks and Regards,

Re: Likely issue with ch341 kernel-module/driver

Hi John. On Thu, Aug 27, 2015 at 1:07 PM, Johan Hovold wrote: > > Try to see if you can get the device to work reliably with some other > driver (vendor driver or other OS) to rule out a broken device. > I tested the serial-usb adapter using a loopback-hardware-tool (confirmed to be perfect). Us

Re: Likely issue with ch341 kernel-module/driver

### Completely lost :( On Wed, Aug 26, 2015 at 11:45 PM, Johan Hovold wrote: > On Wed, Aug 26, 2015 at 08:09:30PM +0200, Peter Stuge wrote: >> Johan Hovold wrote: >> > On Wed, Aug 26, 2015 at 09:39:36PM +0530, Ajay Garg wrote: &g

Likely issue with ch341 kernel-module/driver

Hi all. I am attaching the RS232-TTL via a serial-USB converter on my machine. However, when I connect a putty-session with my embedded-device, I see strange issues (garbage characters transmitted from embedded-device to putty; nothing can be read from putty into embedded-device). It seems that

Is it possible to read the file-allocation-table data-structure on a FAT file-system?

Hi all. Does there exist a API already to read the file-allocation-table data-structure on a FAT(8,16,32) file-system? Having it either in "user", or "kernel" mode will be fine. If not, does there exist some documentation on how one can do that? Will be grateful for any pointers :) Regards, A

Re: How to hack syscall-table, in kernel 2.6+ ?

Thanks Richard, Felipe, Alan. First of all, let me tell you that I am highly previleged talking to some of the most distinguished hackers in the world. Alan, I truly admire you :) So, the use-case I am trying to solve, is that only a particular process should be able to read a group of files, a

How to hack syscall-table, in kernel 2.6+ ?

Hi all. It is well known that the syscall-table had stopped being exported from version 2.6 onwards. So, now as a developer, if I wish to hack into the syscall-table, and change the syscall-function-pointers to my custom-function-pointers (mainly for the reason of adding/preventing access to cert