Re: [PATCH 1/2] module: allow for module error injection

[Thomas Weißschuh]

On 2025-01-22 14:11:13+0100, Daniel Gomez wrote:
> Allow to test kernel module initialization with eBPF error injection
> by forcing errors when any of the below annotated functions with
> ALLOW_ERROR_INJECTION() return.
> 
> Allow to debug and test module load error behaviour when:
> 
> complete_formation(): when module initialization switches from
> MODULE_STATE_UNFORMED to MODULE_STATE_COMING stage.
> 
> do_init_module(): when an error occurs during module initialization and
> before we switch from MODULE_STATE_COMING to MODULE_STATE_LIVE stage.
> 
> module_enable_rodata_ro_after_init(): when an error occurs while
> setting memory to RO after module initialization. This is when module
> initialization reaches MODULE_STATE_LIVE stage.
> 
> Signed-off-by: Daniel Gomez <da.gomez@xxxxxxxxxxx>
> ---
>  kernel/module/main.c       | 3 +++
>  kernel/module/strict_rwx.c | 2 ++
>  2 files changed, 5 insertions(+)
> 
> diff --git a/kernel/module/main.c b/kernel/module/main.c
> index 1fb9ad289a6f8f328fc37c6d93730882d0e6e613..54e6c4d0aab23ae5001a52c26417e7e7957ea3fd 100644
> --- a/kernel/module/main.c
> +++ b/kernel/module/main.c
> @@ -59,6 +59,7 @@
>  #include <linux/codetag.h>
>  #include <linux/debugfs.h>
>  #include <linux/execmem.h>
> +#include <linux/bpf.h>

This should be <linux/error-injection.h>, no?

>  #include <uapi/linux/module.h>
>  #include "internal.h"
>  
> @@ -3089,6 +3090,7 @@ static noinline int do_init_module(struct module *mod)
>  
>  	return ret;
>  }
> +ALLOW_ERROR_INJECTION(do_init_module, ERRNO);
>  
>  static int may_init_module(void)
>  {
> @@ -3225,6 +3227,7 @@ static int complete_formation(struct module *mod, struct load_info *info)
>  	mutex_unlock(&module_mutex);
>  	return err;
>  }
> +ALLOW_ERROR_INJECTION(complete_formation, ERRNO);
>  
>  static int prepare_coming_module(struct module *mod)
>  {

<snip>