linux kernel - Pointer returning NULL from extern structure in C -

linux kernel - Pointer returning NULL from extern structure in C -

i have defined next global construction in .h file:

file1.h

struct kobject_saved { struct kobject* kobject; } extern struct kobject_saved *ksaved;

file1.c

#include <file1.h> struct kobject_saved *ksaved = kmalloc(sizeof(struct kobject_saved), gfp_kernel); ksaved->kobject = some_kobject; // some_kobject initialized pointer kobj

file2.c

#include <file1.h> struct kobject *ko = ksaved->kobject;

here, getting value of kobject null. though phone call file2.c made after initialization happens @ file1.c

can please help me access kobject without losing data? perchance point out going wrong?

many thanks,

update: exact code some_object. getting right address "ko" though..

void save_my_kobject(struct kobject *ko) { ko_saved = kmalloc(sizeof(struct kobject_saved), gfp_kernel); *ko_saved = (struct kobject_saved) { .kobj = ko }; }

some elements of source code missing understand want do, illustration :

struct *ko = ksaved->kobject;

can't right. guess meant :

struct kobject* ko = ksaved->kobject;

you setting global variable, modified 2 source files. not recommended practice (difficult maintain).

anyway, if that's want do, have define global variable in 1 file, , reference sec one, did. extern statement improve remained localized within file2.c.

we don't have exact sequence, don't know how code behaves. apparently doesn't crash, guess malloc file1.c has worked correctly. means file1.c has been run intended. , means problem statement :

ksaved->kobject = some_kobject; // some_kobject initialized pointer kobj

might wrong : maybe some_kobject == null;

c linux-kernel