Messages in this thread | | | From | "Anthony Chee" <> | Subject | Re: undefined reference | Date | Sat, 30 Mar 2002 22:19:01 +0800 |
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> > > >Then I use "make bzImage", I got no error message on compiling inode.c, but > >I got > > > >"fs/fs.o(.text+0x1377d): undefined reference to `func'" > > You cannot do that. The kernel must be self contained. The only way > for the kernel to access module code and data is for the module to > register that code and data when the module is loaded and for the > kernel to access the module via the registration list. > > See any module that handles a filesystem. sys_open() does not call the > module directly. A module registers its file operations on load. The > kernel (dentry_open) calls the module via f->f_op->open. > >
Thanks for your help. I use another apporach to communicate with module, similiar to the method you stated above.
What I did in the kernel source,
1. In fs.h, I added one line in struct super_operations int (*query_module) (struct inode *);
2. In write_inode() of inode.c, added result = inode->i_sb->s_op->query_module(inode);
What I did in the module,
1. Build up my own function, kernel_query_module(struct inode *inode)
2. In init_module(), added struct super_block *sb_ptr; sb_ptr = get_super(MKDEV(8,1)); /* suppose I want to get super_block of /dev/sda1 */ sb_ptr -> s_op -> query_module = &kernel_query_module;
Then, I compile the module and didi not get error message When I compile the kernel, I got the follow error message,
inode.c:195: structure has no member named `query_module'
It made me crazy. Why the module can access the s_op and register the address of kernel_query_module, but not the kernel source? I already added one more item in the struct super_operation, but got the error message the struct has no such member.
Any thing I missed? Thanks.
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