[RFC PATCH v2 9/9] um: pass FD for memory operations when needed

[Benjamin Berg]

Hi,

On Thu, 2024-10-24 at 21:52 +0800, Tiwei Bie wrote:
> On 2024/10/23 22:08, Benjamin Berg wrote:
> [...]
> 
> 
> It looks the memcpy could trigger a crash when UML_SECCOMP is
> enabled:
> 
> [...]
> 
> It can be fixed with changes like below on my machine:
> 
> diff --git a/arch/um/include/shared/skas/mm_id.h
> b/arch/um/include/shared/skas/mm_id.h
> index f2d4c383c958..26d922443454 100644
> --- a/arch/um/include/shared/skas/mm_id.h
> +++ b/arch/um/include/shared/skas/mm_id.h
> @@ -6,6 +6,8 @@
>  #ifndef __MM_ID_H
>  #define __MM_ID_H
>  
> +#include <linux/kconfig.h>
> +
>  #ifdef CONFIG_UML_SECCOMP
>  #define STUB_MAX_FDS 4
>  #else

Hmm, the "#include <linux/kconfig.h>" in userspace code again. I
dropped the include from process.c after Johanne's comment …

Maybe we can really just include kconfig.h. But we can also avoid it by
adding the definition into common-offsets.h, or just keeping a couple
of extra integers around in non-seccomp compiles :-)

Benjamin