What really are options of the "read_format" attribute of the...
I'm currently using the perf_event_open syscall (on Linux systems), and I try to understand a configuration parameter of this syscall wich is given by the struct perf_event_attr structure. It's about...
View Article/sbin/init: error while loading shared libraries: libc.so.6: cannot open...
/sbin/init: error while loading shared libraries: libc.so.6: cannot open shared object files: No such file or directory Kernel panic - not syncing: Attempted to kill init! Pid: 1, comm: init Not...
View ArticleKenel memory configuration 2G/2G user/kernel space [duplicate]
I have a 2GB ARM device that runs the 3.10.17 Linux kernel. The memory split configuration is set to 2G/2G user/kernel space split, but I can choose for the 3G/1G.Does the kernel divide the memory per...
View Articlefedora self-built kernel hangs even before booting (at first step) [migrated]
I'm running Fedora 31 and compiled a kernel with acs patch I needed according to this recipe, but it didn't boot at all(*). I followed these steps:# rpmdev-setuptree # koji download-build --arch=src...
View ArticleWhy no ARP REQUEST send when ARP entry timeout?
I have two hostA/hostB connected directly with ipA/ipB in same IP mask, like this:# hostA # ip addr show Vlan100 137: Vlan100@Bridge: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue...
View ArticleWriting a file in /proc continuouly floods the dmesg
I am trying to read/Write a variable in the linux kernel module using /proc file entry facility. Kernel module compiles successfully but when tried writing it viaecho 1 > My_file This operation...
View ArticleWhat does features of Ethernet devices in ethtool mean? How to changes...
As we know we can use ethtool -k to get features of Ethernet devices, and we can use ethtool -K to change the featueres' status. I want to change some features of Ethernet devices in my C program. I...
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Kernel error: IRQ remapping doesn't support X2APIC mode, disabled x2apic
I need to enable x2apic on Intel(R) Xeon(R) CPU E3-1225 v5 @ 3.30GHz, and I find x2apic was supported in cpuinfo:But when kernel started, I find error message:[ 0.138328] IRQ remapping doesn't support...
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 ArticleWhere i can find about basic linux tutorial ?, especially ubuntu [closed]
Where i can find about basic linux tutorial ?, especially ubuntuFor these tutorial : - About basic linux command lines - About basic C programming in linux (system call, toolchain, ...) - and About...
View ArticleJ1939 in Linux Kernel [duplicate]
Iam working with imx6ull board. Iam developing software stack for CAN J1939 protocol.In the development stage i got to know that we need to add support for J1939 in Kernel. Iam using Linux kernel...
View ArticleLinux Platform Drivers: How to pass DMA Ops to cells?
I am writing a multi function driver (mfd) for a PCIe device with DMA capabilities. Several cells are added through mfd_add_devices.I found that the struct device* of the top level mfd driver has the...
View ArticleHow to remount root after chroot [closed]
My system run chroot after kernel started. When I run mount -o size=1024M,remount,rw / I got an error:mount: can't find / in /proc/mountsBy the way, my rootfs is ramfs.
View ArticleGet 'cmdline' as exported in /proc/$PID/cmdline from Linux Kernel Code
I'm trying to get the cmdline of a process as it is shown in /proc/$PID/cmdline by it's PID from within Kernel Context.I can access the task_struct and it's field "comm", which however only holds 16...
View ArticleMap sharing between different ebpf program types
Is it possible to share ebpf maps between different program types. I need to share a map between a tc-bpf program and a cgroup bpf program. This should be possible if the map is pinned to file system...
View ArticleWhy can't I stop this thread from the Linux kernel?
Edit: Clarification -- This is Linux kernel code.I send SIGSTOP to a thread and then call wait_task_inactive to make sure it stopped. But the CPU RCU-stalls judging by the kernel log. I have no...
View ArticleHow to allocate large contiguous, memory regions in Linux
Yes, I will ultimately be using this for DMA but lets leave coherency aside for the moment. I have 64 bit BAR registers, therefore, AFAIK, all of RAM (e.g. higher than 4G) is available for DMA.I am...
View ArticleWhat are the relations between a kernel control path a kernel thread?
Understanding The Linux Kernel says:A kernel control path denotes the sequence of instructions executed by the kernel to handle a system call, an exception, or an interrupt.and Besides user processes,...
View ArticleWhat is the significance of THIS_MODULE in Linux kernel module drivers?
In Linux device driver development, the file_operations structure uses struct module *owner. What is the use of this structure when we always initialize it with THIS_MODULE?When can this field be set...
View Articlelinux headers are consuming a lot of disk space on the EC2 machine. Is it...
EC2 machine on aws is filled with multiple linux headers and currently / is 100% full on disk space. I ran commands like apt-get autoremove but it is throwing an error saying No apport report written...
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