How can I create my own defined MTD device through kernel command line on ARM...
At first, I didn't add any kernel parameter and then got MTD device/proc/mtd: dev: size erasesize name mtd0: 01000000 00010000 "spi1.0"then, I added setenv mtdids "mtdids=spi1.0", and setenv mtdparts...
View ArticleEBPF: pointer arithmetic on PTR_TO_PACKET_END prohibited
I am trying to write a kernel module for filtering using the following example. On Ubuntu 18.04 with kernel 5.3.0 it's compiled and works perfectly fine.However, when the same example is compiled on...
View ArticleSave old sk_data_ready
After creating a socket, I set a custom listen_data_ready(struct sock *sk) callback. However, for accepted socket I want to reset the callback to sock_def_readable.sk->sk_user_data =...
View ArticleHow to write a network device driver to edit (encrypt) Network packet between...
I try to use this sample to get the network packet and I need encrypt data before reach to destinations. like server send a message like: hello-world I need to encrypt it before reaching to...
View Articlepossibly bug: modprobe ip_tables doesn't work
I want to test some Linux conntrack behavior. So I should turn on iptables before connection tracking system. I tried modprobe ip_tables as root but it fails with:modprobe: ERROR:...
View ArticleGetting kernel config from defconfig
The title says it all: I need the .config file that was used for compiling a kernel, but all I have is the defconfig file. I've seen instructions on how to produce the latter from the former, but not...
View ArticleDisadvantage of using mutex in interrupt context
What is Disadvantage of using mutex in interrupt context.Why spin lock is preferred here.
View ArticlePath lookup in linux kernel 4.15
I'm trying to write a simple kernel module, just for didactic purpose. In particular, what is giving me headaches is the path lookup. I'd like to have a sysfs entry and in the store operation I want to...
View ArticleHow to fix dependency on devm_kmalloc for the phy driver?
I am trying to build a custom phyDriver in my Ubuntu Machine - 18.04. However, I get errors on insmod like - The dmesg tells me -57810.400155] phyDriver: module license 'unspecified' taints kernel....
View ArticleBooting Linux on Qemu
I am trying to boot linux kernel for ARM in Ubuntu with TFTP. I get an error like this.What could be the cause of this error?enter image description here
View Articlen_gsm Line discipline problem with Telit LE910B1 Modem and CMUX
We are using a Telit LE910B1 modem on an embedded device running a Linux 5.1.0 kernel. We only have a single UART available for the modem so we are using n_gsm line discipline with CMUX on the modem....
View ArticleChanging default permissions on IOctl cdev
I am adding an IOctl call from the native OpenGL framework on an Android device such that I can log frame information in the kernel via a tracing kernel module. In my kernel module I am creating the...
View ArticleConvert string with time data to rtc_time structure in Linux kernel
I can easily convert kernel data type struct rtc_time to string with help sprintf(), but I can't do reverse operation: string "Thu Aug 23 14:55:02 2001" to rtc_time structure Should I write my own...
View ArticleDriver binding using device tree without compatible string in the driver
I saw one scenario where "struct of_device_id" is not defined in the driver, but in the device tree(dts) file compatible string added for the same device entry. Following is the sample device tree...
View Articlemmap, msync and linux process termination
I want to use mmap to implement persistence of certain portions of program state in a C program running under Linux by associating a fixed-size struct with a well known file name using mmap() with the...
View ArticleHow to remove conntrack entry from within Linux kernel?
I need to delete a conntrack entry in the kernel. There are numerous functions like nf_ct_delete and nf_ct_put. At the moment I use both on a skb->nfct (block on every tracked skb). It seems to work...
View ArticleHow Linux arm64 switch between AArch32 and AArch64
Linux supports running 32-bit application, as long askernel enables CONFIG_COMPATthe hardware supports the AArch32I assume that 32-bit application must run in arm AArch32 execution state and if the...
View ArticleIs Alpine Linux an implementation of a Unikernel?
I've been reading a lot about Docker containers and Unikernels and how to run lightweight environment with my own applications.I understand that Linux containers and Unikernels are different things, as...
View ArticleGet NFS client IP address in a kernel module
I'm working on a kernel module to track the operations performed by NFS clients on my server. I can intercept the file operations using a hacky way (hijacking the vfs layer) but I can't retrieve the IP...
View ArticleWhy Linux distro Debian is the best linux distro for programmers? [closed]
I searched in several forums for user feedback about Linux distributions, why most of the forum people say Debian is best for programming?
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