Re: [PATCH/RFC] module: replace module_layout with module_memory

On Thu, Jan 19, 2023 at 12:29 AM Song Liu [off-list ref] wrote:

On Wed, Jan 18, 2023 at 9:35 PM Christoph Hellwig [off-list ref] wrote:

quoted

On Wed, Jan 18, 2023 at 01:52:51PM -0800, Song Liu wrote:

quoted

In this way we can use the array in the for loops, and use mod->core_text,
etc. when we only need to access one of them.

Just use the array please instead of making it too ugly.  If that
is the only sensible way to iterate we have a good argument for the
array and can live with it.

Hmm.. I think it won't be ugly outside of the struct definition...
Alternatively, how about use something like

#define core_text mod_mem[MOD_MEM_TYPE_TEXT]
...

which is similar to

struct sock {
        /*
         * Now struct inet_timewait_sock also uses sock_common, so please just
         * don't add nothing before this first member (__sk_common) --acme
         */
        struct sock_common      __sk_common;
#define sk_node                 __sk_common.skc_node
#define sk_nulls_node           __sk_common.skc_nulls_node
...
};

So here are the two versions, both with secondary addr_[min|max] for
CONFIG_ARCH_WANTS_MODULES_DATA_IN_VMALLOC.

v2. Just use mod_mem array:
https://git.kernel.org/pub/scm/linux/kernel/git/song/md.git/commit/?h=remotes/song-md/new_module_alloc_build_test_v2

v3. mod_mem array and the defines:
#define mod_core_text mod_mem[MOD_MEM_TYPE_TEXT]
#define mod_core_data mod_mem[MOD_MEM_TYPE_DATA]
etc.
https://git.kernel.org/pub/scm/linux/kernel/git/song/md.git/commit/?h=remotes/song-md/new_module_alloc_build_test_v3

I personally like the v3 better. Please share you
comments on this.

Thanks,
Song