system-calls

问题 I'm trying to add a simple helloworld System Call to kernel 3.13.0-37-generic on 64 bit system. I'll try to show what I did so far step by step : 1- I've downloaded kernel source by : sudo apt-get source linux-image-3.13.0-37-generic After that, kernel source files extracted to /usr/src/ 2- Define a new system call sys_hello() : I've created a directory with hello name in the kernel source directory in /usr/src/linux-3.13/ And I created a hello.c file in hello directory with below content :

问题 I am trying to print a number that I have stored. I'm not sure if I am close or way off. Any help would be appreciated though. Here is my code: .data .balign 4 a: .word 4 .text .global main main: ldr r0, addr_of_a mov r1, #8 str r1, [r0] write: mov r0, #1 ldr r1, addr_of_a mov r2, #4 mov r7, #4 swi #0 bx lr addr_of_a: .word a It compiles and runs, but I don't see anything printed. From what I understand, I need the address of where to start printing in r1, how many bytes in r2, the file

来源： https://stackoverflow.com/questions/50571275/why-does-a-syscall-clobber-rcx-and-r11

来源： https://stackoverflow.com/questions/64409124/cmp-instruction-and-je-not-firing

来源： https://stackoverflow.com/questions/64409124/cmp-instruction-and-je-not-firing

来源： https://stackoverflow.com/questions/48541868/how-to-append-to-a-file-using-x86-64-linux-system-calls

来源： https://stackoverflow.com/questions/48541868/how-to-append-to-a-file-using-x86-64-linux-system-calls

来源： https://stackoverflow.com/questions/64084547/how-to-call-sys-open-rather-than-sys-openat-when-calling-open

来源： https://stackoverflow.com/questions/55013836/using-sched-setaffinity-in-linux-kernel

来源： https://stackoverflow.com/questions/40967594/does-gettimeofday-on-macos-use-a-system-call