This code uses the low-level resource API to track parameters of the
vm_mmap call, but it doesn't do anything with them, because the mm
teardown code takes care of tearing down the mmaps. Delete it.

Signed-off-by: Brendan Jackman <jackmanb@google.com>
---
 lib/kunit/user_alloc.c | 76 ++++----------------------------------------------
 1 file changed, 6 insertions(+), 70 deletions(-)

diff --git a/lib/kunit/user_alloc.c b/lib/kunit/user_alloc.c
index b8cac765e6204..564f5566641d5 100644
--- a/lib/kunit/user_alloc.c
+++ b/lib/kunit/user_alloc.c
@@ -7,21 +7,6 @@
 #include <linux/kthread.h>
 #include <linux/mm.h>
 
-struct kunit_vm_mmap_resource {
-	unsigned long addr;
-	size_t size;
-};
-
-/* vm_mmap() arguments */
-struct kunit_vm_mmap_params {
-	struct file *file;
-	unsigned long addr;
-	unsigned long len;
-	unsigned long prot;
-	unsigned long flag;
-	unsigned long offset;
-};
-
 int kunit_attach_mm(void)
 {
 	struct mm_struct *mm;
@@ -50,67 +35,18 @@ int kunit_attach_mm(void)
 }
 EXPORT_SYMBOL_GPL(kunit_attach_mm);
 
-static int kunit_vm_mmap_init(struct kunit_resource *res, void *context)
-{
-	struct kunit_vm_mmap_params *p = context;
-	struct kunit_vm_mmap_resource vres;
-	int ret;
-
-	ret = kunit_attach_mm();
-	if (ret)
-		return ret;
-
-	vres.size = p->len;
-	vres.addr = vm_mmap(p->file, p->addr, p->len, p->prot, p->flag, p->offset);
-	if (!vres.addr)
-		return -ENOMEM;
-	res->data = kmemdup(&vres, sizeof(vres), GFP_KERNEL);
-	if (!res->data) {
-		vm_munmap(vres.addr, vres.size);
-		return -ENOMEM;
-	}
-
-	return 0;
-}
-
-static void kunit_vm_mmap_free(struct kunit_resource *res)
-{
-	struct kunit_vm_mmap_resource *vres = res->data;
-
-	/*
-	 * Since this is executed from the test monitoring process,
-	 * the test's mm has already been torn down. We don't need
-	 * to run vm_munmap(vres->addr, vres->size), only clean up
-	 * the vres.
-	 */
-
-	kfree(vres);
-	res->data = NULL;
-}
-
 unsigned long kunit_vm_mmap(struct kunit *test, struct file *file,
 			    unsigned long addr, unsigned long len,
 			    unsigned long prot, unsigned long flag,
 			    unsigned long offset)
 {
-	struct kunit_vm_mmap_params params = {
-		.file = file,
-		.addr = addr,
-		.len = len,
-		.prot = prot,
-		.flag = flag,
-		.offset = offset,
-	};
-	struct kunit_vm_mmap_resource *vres;
+	int err;
 
-	vres = kunit_alloc_resource(test,
-				    kunit_vm_mmap_init,
-				    kunit_vm_mmap_free,
-				    GFP_KERNEL,
-				    &params);
-	if (vres)
-		return vres->addr;
-	return 0;
+	err = kunit_attach_mm();
+	if (err)
+		return err;
+
+	return vm_mmap(file, addr, len, prot, flag, offset);
 }
 EXPORT_SYMBOL_GPL(kunit_vm_mmap);
 

-- 
2.51.2

On Wed, 24 Dec 2025 at 00:18, Brendan Jackman <jackmanb@google.com> wrote:
>
> This code uses the low-level resource API to track parameters of the
> vm_mmap call, but it doesn't do anything with them, because the mm
> teardown code takes care of tearing down the mmaps. Delete it.
>
> Signed-off-by: Brendan Jackman <jackmanb@google.com>
> ---

This makes sense. Maybe there's a case where tracking mmaps as
resources could be useful in the future, but I can't think of any off
the top of my head, so this is just wasteful for now.

Reviewed-by: David Gow <davidgow@google.com>

Cheers,
-- David



>  lib/kunit/user_alloc.c | 76 ++++----------------------------------------------
>  1 file changed, 6 insertions(+), 70 deletions(-)
>
> diff --git a/lib/kunit/user_alloc.c b/lib/kunit/user_alloc.c
> index b8cac765e6204..564f5566641d5 100644
> --- a/lib/kunit/user_alloc.c
> +++ b/lib/kunit/user_alloc.c
> @@ -7,21 +7,6 @@
>  #include <linux/kthread.h>
>  #include <linux/mm.h>
>
> -struct kunit_vm_mmap_resource {
> -       unsigned long addr;
> -       size_t size;
> -};
> -
> -/* vm_mmap() arguments */
> -struct kunit_vm_mmap_params {
> -       struct file *file;
> -       unsigned long addr;
> -       unsigned long len;
> -       unsigned long prot;
> -       unsigned long flag;
> -       unsigned long offset;
> -};
> -
>  int kunit_attach_mm(void)
>  {
>         struct mm_struct *mm;
> @@ -50,67 +35,18 @@ int kunit_attach_mm(void)
>  }
>  EXPORT_SYMBOL_GPL(kunit_attach_mm);
>
> -static int kunit_vm_mmap_init(struct kunit_resource *res, void *context)
> -{
> -       struct kunit_vm_mmap_params *p = context;
> -       struct kunit_vm_mmap_resource vres;
> -       int ret;
> -
> -       ret = kunit_attach_mm();
> -       if (ret)
> -               return ret;
> -
> -       vres.size = p->len;
> -       vres.addr = vm_mmap(p->file, p->addr, p->len, p->prot, p->flag, p->offset);
> -       if (!vres.addr)
> -               return -ENOMEM;
> -       res->data = kmemdup(&vres, sizeof(vres), GFP_KERNEL);
> -       if (!res->data) {
> -               vm_munmap(vres.addr, vres.size);
> -               return -ENOMEM;
> -       }
> -
> -       return 0;
> -}
> -
> -static void kunit_vm_mmap_free(struct kunit_resource *res)
> -{
> -       struct kunit_vm_mmap_resource *vres = res->data;
> -
> -       /*
> -        * Since this is executed from the test monitoring process,
> -        * the test's mm has already been torn down. We don't need
> -        * to run vm_munmap(vres->addr, vres->size), only clean up
> -        * the vres.
> -        */
> -
> -       kfree(vres);
> -       res->data = NULL;
> -}
> -
>  unsigned long kunit_vm_mmap(struct kunit *test, struct file *file,
>                             unsigned long addr, unsigned long len,
>                             unsigned long prot, unsigned long flag,
>                             unsigned long offset)
>  {
> -       struct kunit_vm_mmap_params params = {
> -               .file = file,
> -               .addr = addr,
> -               .len = len,
> -               .prot = prot,
> -               .flag = flag,
> -               .offset = offset,
> -       };
> -       struct kunit_vm_mmap_resource *vres;
> +       int err;
>
> -       vres = kunit_alloc_resource(test,
> -                                   kunit_vm_mmap_init,
> -                                   kunit_vm_mmap_free,
> -                                   GFP_KERNEL,
> -                                   &params);
> -       if (vres)
> -               return vres->addr;
> -       return 0;
> +       err = kunit_attach_mm();
> +       if (err)
> +               return err;
> +
> +       return vm_mmap(file, addr, len, prot, flag, offset);
>  }
>  EXPORT_SYMBOL_GPL(kunit_vm_mmap);
>
>
> --
> 2.51.2
>