Do I need to include a library? Can anyone please elaborate in it?
I know is used to get the process id of the current task where is being called from
But I want to printk something with current->pid
printk("My current process id/pid is %d\n", current->pid);
...and is giving me an error
error: dereferencing pointer to incomplete type
You're looking for #include <linux/sched.h>. That's where task_struct is declared.
#include <linux/kernel.h> is needed as well. Thanks!Your code should work. You are probably missing some header.
current is a per-cpu variable defined in linux/arch/x86/include/asm/current.h (all the code is for the case of x86):
DECLARE_PER_CPU(struct task_struct *, current_task); static __always_inline struct task_struct *get_current(void) { return percpu_read_stable(current_task); } #define current get_current() current points to the task running on a CPU at a given moment. Its type is struct task_struct and it is defined in linux/include/linux/sched.h:
struct task_struct { ... pid_t pid; // process identifier pid_t tgid; // process thread group id ... }; You can browse the code for these files in the Linux Cross Reference:
