[PATCH RESEND 2/3] binder: remove binder_alloc_set_vma()

From: Carlos Llamas
Date: Tue Sep 06 2022 - 10:41:56 EST


The mmap_locked asserts here are not needed since this is only called
back from the mmap stack in ->mmap() and ->close() which always acquire
the lock first. Remove these asserts along with binder_alloc_set_vma()
altogether since it's trivial enough to be consumed by callers.

Cc: Liam R. Howlett <Liam.Howlett@xxxxxxxxxx>
Signed-off-by: Carlos Llamas <cmllamas@xxxxxxxxxx>
---
drivers/android/binder_alloc.c | 25 ++-----------------------
1 file changed, 2 insertions(+), 23 deletions(-)

diff --git a/drivers/android/binder_alloc.c b/drivers/android/binder_alloc.c
index 749a4cd30a83..1c39cfce32fa 100644
--- a/drivers/android/binder_alloc.c
+++ b/drivers/android/binder_alloc.c
@@ -309,27 +309,6 @@ static int binder_update_page_range(struct binder_alloc *alloc, int allocate,
return vma ? -ENOMEM : -ESRCH;
}

-
-static inline void binder_alloc_set_vma(struct binder_alloc *alloc,
- struct vm_area_struct *vma)
-{
- unsigned long vm_start = 0;
-
- /*
- * Allow clearing the vma with holding just the read lock to allow
- * munmapping downgrade of the write lock before freeing and closing the
- * file using binder_alloc_vma_close().
- */
- if (vma) {
- vm_start = vma->vm_start;
- mmap_assert_write_locked(alloc->mm);
- } else {
- mmap_assert_locked(alloc->mm);
- }
-
- alloc->vma_addr = vm_start;
-}
-
static inline struct vm_area_struct *binder_alloc_get_vma(
struct binder_alloc *alloc)
{
@@ -793,7 +772,7 @@ int binder_alloc_mmap_handler(struct binder_alloc *alloc,
buffer->free = 1;
binder_insert_free_buffer(alloc, buffer);
alloc->free_async_space = alloc->buffer_size / 2;
- binder_alloc_set_vma(alloc, vma);
+ alloc->vma_addr = vma->vm_start;

return 0;

@@ -983,7 +962,7 @@ int binder_alloc_get_allocated_count(struct binder_alloc *alloc)
*/
void binder_alloc_vma_close(struct binder_alloc *alloc)
{
- binder_alloc_set_vma(alloc, NULL);
+ alloc->vma_addr = 0;
}

/**
--
2.37.2.789.g6183377224-goog