Re: [PATCH v4 19/20] tools/testing/vma: add test to assert MAP_PRIVATE-/dev/zero is anon

[David Hildenbrand (Arm)]

On 8/6/26 22:21, Lorenzo Stoakes (ARM) wrote:
> Now we've made MAP_PRIVATE-mapped /dev/zero mappings truly anonymous, add a
> VMA userland test to assert that this is the case and everything is as
> we would expect for an anonymous mapping.
> 
> Signed-off-by: Lorenzo Stoakes (ARM) <ljs@xxxxxxxxxx>
> ---
>  tools/testing/vma/include/dup.h |  1 +
>  tools/testing/vma/tests/mmap.c  | 50 +++++++++++++++++++++++++++++++++++++++++
>  2 files changed, 51 insertions(+)
> 
> diff --git a/tools/testing/vma/include/dup.h b/tools/testing/vma/include/dup.h
> index aee36707abdd..41203b1c2323 100644
> --- a/tools/testing/vma/include/dup.h
> +++ b/tools/testing/vma/include/dup.h
> @@ -20,6 +20,7 @@ struct task_struct *get_current(void);
>  
>  #define MAJOR(dev)	((unsigned int) ((dev) >> MINORBITS))
>  #define MINOR(dev)	((unsigned int) ((dev) & MINORMASK))
> +#define MKDEV(ma, mi)	(((ma) << MINORBITS) | (mi))
>  
>  #define S_IFMT  00170000
>  #define S_IFCHR  0020000
> diff --git a/tools/testing/vma/tests/mmap.c b/tools/testing/vma/tests/mmap.c
> index c85bc000d1cb..ebe01362e530 100644
> --- a/tools/testing/vma/tests/mmap.c
> +++ b/tools/testing/vma/tests/mmap.c
> @@ -45,7 +45,57 @@ static bool test_mmap_region_basic(void)
>  	return true;
>  }
>  
> +static int dummy_mmap_prepare(struct vm_area_desc *desc)
> +{
> +	return 0;
> +}
> +
> +static bool test_pure_anon_dev_zero(void)
> +{

Ah, just one comment: should we call this something like
"test_map_private_dev_zero", at least that'd be clearer for me.


-- 
Cheers,

David