On Tue, Jul 21, 2009 at 12:45 PM, Siddu <[email protected]> wrote:
> > > On Tue, Jul 21, 2009 at 11:13 AM, er krishna <[email protected]> wrote: > >> >> I am again repeating the steps, i found something interested, when I am >> doing make after making EXPORT_SYMBOL entries in fs/drop_caches.c ( during >> kernel compilation); I am getting following warning messages for each of the >> exported function from this file only, the messages are: >> >> data definition has no type or storage class > > > >> >> >> type defaults to 'int' in declaration of 'EXPORT_SYMBOL' >> >> parameter names (without types) in function declaration >> >> Although these are the warning messages, but why it is coming from >> fs/drop_caches file only. The function which I have exported from >> fs/buffer.c and block/genhd.c are easily exported and there is no warning >> messages against any exported function from other than fs/drop_caches.c > > Could you tell what other functions were you able to export successfully > from buffer.c and genhd.c > [r...@centos2 linux-2.6.26]# grep myfunction System.map c0175a00 T myfunction c0177cad T myfunction2 c02ac3a5 T myfunction3 c063e178 r __ksymtab_myfunction2 c063ea30 r __ksymtab_myfunction3 c06492da r __kstrtab_myfunction2 c064b00c r __kstrtab_myfunction3 [r...@centos2 linux-2.6.26]# Check it out myfunctio2 & myfunction3 I am able 2 export from fs/buffer.c and block/genhd.c but I am not able to export any of the function from fs/dropcacahe.c & whenever I do make after doing the entry in dropcache.c I am always getting following error message : [r...@centos2 linux-2.6.26]# cat kk fs/drop_caches.c:85: warning: data definition has no type or storage class fs/drop_caches.c:85: warning: type defaults to ‘int’ in declaration of ‘EXPORT_SYMBOL’ fs/drop_caches.c:85: warning: parameter names (without types) in function declaration fs/drop_caches.c:86: warning: data definition has no type or storage class fs/drop_caches.c:86: warning: type defaults to ‘int’ in declaration of ‘EXPORT_SYMBOL’ fs/drop_caches.c:86: warning: parameter names (without types) in function declaration fs/drop_caches.c:87: warning: data definition has no type or storage class fs/drop_caches.c:87: warning: type defaults to ‘int’ in declaration of ‘EXPORT_SYMBOL’ fs/drop_caches.c:87: warning: parameter names (without types) in function declaration fs/drop_caches.c:88: warning: data definition has no type or storage class fs/drop_caches.c:88: warning: type defaults to ‘int’ in declaration of ‘EXPORT_SYMBOL’ fs/drop_caches.c:88: warning: parameter names (without types) in function declaration fs/drop_caches.c:89: warning: data definition has no type or storage class fs/drop_caches.c:89: warning: type defaults to ‘int’ in declaration of ‘EXPORT_SYMBOL’ fs/drop_caches.c:89: warning: parameter names (without types) in function declaration make[2]: *** Deleting file `fs/configfs/inode.o' make[2]: *** [fs/configfs/inode.o] Interrupt make[1]: *** [fs/configfs] Interrupt make: *** [fs] Interrupt [r...@centos2 linux-2.6.26]# So, these are the two clues, can anybody help me out. Peter , I have tried with extern optaion also , but the results are same. Thanks & Best regards, Krishna > >> On Tue, Jul 21, 2009 at 10:30 AM, Mulyadi Santosa < >> [email protected]> wrote: >> >>> On Mon, Jul 20, 2009 at 9:40 PM, er krishna<[email protected]> wrote: >>> > I have exported three functions from fs/dropcaches.c by making their >>> > function declaration in linux/mm.h, compiled the corresponding 2.6.26 >>> > kernel & got their entries in System.map file as follows: >>> > >>> > >>> > c0174d98 T drop_slab >>> > c0174db2 T drop_pagecache >>> > c0174ea7 T drop_caches_sysctl_handler >>> >>> Upper case T, according to "man nm" means it's a global symbol. In >>> other word, other function located in separate object file could >>> reference it. OK, seems you do correctly here in exporting symbol >>> >>> > These entries are quite different from the actual exported functions >>> from >>> > other files, it has only T option. >>> >>> What do you mean by the above paragraph? >>> >> >> >> Mylyadi, Actually when we do compilation, there are warning messages and >> when i do insmod there is error and in dmesg it shows that the above symbols >> are not resolved (it means there is a linking error) , I have exported some >> other function from other file and checked all those entries in >> /proc/kallsyms and in System.map file. These are different in nature. Thats >> why I asked ? >> >>> Please paste the relevant portion of /proc/kallsym and System.map so that > all of us can see in what way they differ > >> >> >> As I have declared their definition in linux/mm.h, I dont think that i >> have to do extern in my module coz i have included linux/mm.h after making >> proper declaration of these functions. But let me check with extern once >> more. >> >> >> >> >> >>> >>> And as far as I can see here, they are warning messages so there's a >>> chance the final kernel module can be successfully build. What happen >>> if you do "insmod -f"? Does it work as expected? >>> >> >> I will let you know after repeating the above steps, coz I am once again >> compiling the kernel. >> >> >> >> >>> >>> -- >>> regards, >>> >>> Mulyadi Santosa >>> Freelance Linux trainer >>> blog: the-hydra.blogspot.com >>> >> Other than that, as Peter has suggested, are you sure you have >>> declared drop_slab() etc as "extern" function in your module? >>> >> > > > > -- > Regards, > ~Sid~ > http://sidsenclave.blogspot.com >
