On Mon, Jul 14, 2025 at 11:53:16AM -0700, Tiffany Yang wrote:
Tests can allocate from virtual memory using kunit_vm_mmap(), which transparently creates and attaches an mm_struct to the test runner if one is not already attached. This is suitable for most cases, except for when the code under test must access a task's mm before performing an mmap. Expose kunit_attach_mm() as part of the interface for those cases. This does not change the existing behavior.
Cc: David Gow davidgow@google.com Signed-off-by: Tiffany Yang ynaffit@google.com
include/kunit/test.h | 12 ++++++++++++ lib/kunit/user_alloc.c | 4 ++-- 2 files changed, 14 insertions(+), 2 deletions(-)
diff --git a/include/kunit/test.h b/include/kunit/test.h index 39c768f87dc9..d958ee53050e 100644 --- a/include/kunit/test.h +++ b/include/kunit/test.h @@ -531,6 +531,18 @@ static inline char *kunit_kstrdup(struct kunit *test, const char *str, gfp_t gfp */ const char *kunit_kstrdup_const(struct kunit *test, const char *str, gfp_t gfp);
+/**
- kunit_attach_mm() - Create and attach a new mm if it doesn't already exist.
- Allocates a &struct mm_struct and attaches it to @current. In most cases, call
- kunit_vm_mmap() without calling kunit_attach_mm() directly. Only necessary when
- code under test accesses the mm before executing the mmap (e.g., to perform
- additional initialization beforehand).
- Return: 0 on success, -errno on failure.
- */
+int kunit_attach_mm(void);
/**
- kunit_vm_mmap() - Allocate KUnit-tracked vm_mmap() area
- @test: The test context object.
diff --git a/lib/kunit/user_alloc.c b/lib/kunit/user_alloc.c index 46951be018be..b8cac765e620 100644 --- a/lib/kunit/user_alloc.c +++ b/lib/kunit/user_alloc.c @@ -22,8 +22,7 @@ struct kunit_vm_mmap_params { unsigned long offset; };
-/* Create and attach a new mm if it doesn't already exist. */ -static int kunit_attach_mm(void) +int kunit_attach_mm(void) { struct mm_struct *mm;
@@ -49,6 +48,7 @@ static int kunit_attach_mm(void)
return 0;} +EXPORT_SYMBOL_GPL(kunit_attach_mm);
static int kunit_vm_mmap_init(struct kunit_resource *res, void *context) { -- 2.50.0.727.gbf7dc18ff4-goog
LGTM!
Reviewed-by: Carlos Llamas cmllamas@google.com