Re: [PATCH] x86/kbuild: enable modversions for symbols exported from asm

Michal Marek
2016-12-14T10:13:53Z

On 2016-12-14 10:15, Michal Marek wrote:
> A minimal example would be
>
> t1.c:
> struct s1;
> struct s2 {
> int i;
> }
> struct s3 {
> struct s1 *ptr1;
> struct s2 *ptr2;
> }
> void foo(struct s3*);
> EXPORT_SYMBOL(foo);
>
> t2.c:
> struct s1 {
> int j;
> }
> struct s2;
> struct s3 {
> struct s1 *ptr1;
> struct s2 *ptr2;
> }
> void foo(struct s3*);
> EXPORT_SYMBOL(foo);

Note that the above, if passed to genksyms verbatim, would result in
genksyms treating all the types as internal. Here is a complete
example including linemarkers:

$ cat t1.i
# 1 "t1.c"
# 1 "<built-in>"
# 1 "<command-line>"
# 1 "t1.c"
# 1 "t1.h" 1
# 1 "t.h" 1
struct s1;
struct s2;
struct s3 {
struct s1 *ptr1;
struct s2 *ptr2;
};
# 2 "t1.h" 2
struct s2 {
int i;
};
# 2 "t1.c" 2
void foo(struct s3 *s) { }
EXPORT_SYMBOL(foo);

$ cat t2.i
# 1 "t2.c"
# 1 "<built-in>"
# 1 "<command-line>"
# 1 "t2.c"
# 1 "t2.h" 1
# 1 "t.h" 1
struct s1;
struct s2;
struct s3 {
struct s1 *ptr1;
struct s2 *ptr2;
};
# 2 "t2.h" 2
struct s1 {
int j;
};
# 2 "t2.c" 2
void foo(struct s3 *s) { }
EXPORT_SYMBOL(foo);

$ ./scripts/genksyms/genksyms -D <t1.i
Export foo == <void foo ( struct s3 { struct s1 { UNKNOWN } * ptr1 ; struct s2 { int i ; } * ptr2 ; } * ) >
__crc_foo = 0xf731cef8 ;

$ ./scripts/genksyms/genksyms -D <t2.i
Export foo == <void foo ( struct s3 { struct s1 { int j ; } * ptr1 ; struct s2 { UNKNOWN } * ptr2 ; } * ) >
__crc_foo = 0xc925dae5 ;

Michal