Hello. I can't solve problem that happens while I'm making my kernel module.
part of my module:
// ...
#include <linux/sched.h>
//....
static u32 task_syscall_entry(enum utrace_resume_action action,
??????????????????????????????? struct utrace_engine *engine,
??????????????????????????????? struct task_struct *task,
??????????????????????????????? struct pt_regs *regs){
??? // ...
??????? show_regs(regs);
}
But, while making I get:
WARNING: "show_regs" [/home/tehhi/module/trace.ko] undefined!
extern void show_regs(struct pt_regs *);? define in header
linux/sched.h, place of source code is
linux/arch/x86/kernel/process_32.c
It use extern void __show_regs(struct pt_regs *); and extern
asmlinkage void __backtrace(void);
I think that extern means that I can use it (and there are no static
symbols in this function).
When trying to insert module, it predictably complains of an unknown
symbol show_regs.
What am I missing here?
Thanks in advance.
On Wed, Nov 25, 2009 at 1:27 PM, Tanya Gornak <[email protected]> wrote:
> Hello. I can't solve problem that happens while I'm making my kernel module.
>
> part of my module:
> // ...
> #include <linux/sched.h>
> //....
> static u32 task_syscall_entry(enum utrace_resume_action action,
> ??????????????????????????????? struct utrace_engine *engine,
> ??????????????????????????????? struct task_struct *task,
> ??????????????????????????????? struct pt_regs *regs){
> ??? // ...
> ??????? show_regs(regs);
>
> }
> But, while making I get:
>
> WARNING: "show_regs" [/home/tehhi/module/trace.ko] undefined!
>
> extern void show_regs(struct pt_regs *);? define in header
> linux/sched.h, place of source code is
> linux/arch/x86/kernel/process_32.c
> It use extern void __show_regs(struct pt_regs *); and extern
> asmlinkage void __backtrace(void);
> I think that extern means that I can use it (and there are no static
> symbols in this function).
>
> When trying to insert module, it predictably complains of an unknown
> symbol show_regs.
>
> What am I missing here?
You're using a function in a module which is not exported to modules.
See http://lwn.net/images/pdf/LDD3/ch02.pdf for more details.
--
Regards/Gruss,
Boris