[PATCH v2 21/28] binder: make oversized buffer code more readable

From: Carlos Llamas
Date: Fri Dec 01 2023 - 12:24:40 EST


The sections in binder_alloc_new_buf_locked() dealing with oversized
buffers are scattered which makes them difficult to read. Instead,
consolidate this code into a single block to improve readability.

No functional change here.

Signed-off-by: Carlos Llamas <cmllamas@xxxxxxxxxx>
---
drivers/android/binder_alloc.c | 21 ++++++++++-----------
1 file changed, 10 insertions(+), 11 deletions(-)

diff --git a/drivers/android/binder_alloc.c b/drivers/android/binder_alloc.c
index c9292eee8fee..ad9b73c6ddb7 100644
--- a/drivers/android/binder_alloc.c
+++ b/drivers/android/binder_alloc.c
@@ -483,32 +483,31 @@ static struct binder_buffer *binder_alloc_new_buf_locked(
goto out;
}

- if (n == NULL) {
+ if (buffer_size != size) {
+ /* Found an oversized buffer and needs to be split */
buffer = rb_entry(best_fit, struct binder_buffer, rb_node);
buffer_size = binder_alloc_buffer_size(alloc, buffer);
+
+ WARN_ON(n || buffer_size == size);
+ new_buffer->user_data = buffer->user_data + size;
+ list_add(&new_buffer->entry, &buffer->entry);
+ new_buffer->free = 1;
+ binder_insert_free_buffer(alloc, new_buffer);
+ new_buffer = NULL;
}

binder_alloc_debug(BINDER_DEBUG_BUFFER_ALLOC,
"%d: binder_alloc_buf size %zd got buffer %pK size %zd\n",
alloc->pid, size, buffer, buffer_size);

- WARN_ON(n && buffer_size != size);
-
has_page_addr = (buffer->user_data + buffer_size) & PAGE_MASK;
end_page_addr = PAGE_ALIGN(buffer->user_data + size);
if (end_page_addr > has_page_addr)
end_page_addr = has_page_addr;
binder_allocate_page_range(alloc, PAGE_ALIGN(buffer->user_data),
end_page_addr);
- if (buffer_size != size) {
- new_buffer->user_data = buffer->user_data + size;
- list_add(&new_buffer->entry, &buffer->entry);
- new_buffer->free = 1;
- binder_insert_free_buffer(alloc, new_buffer);
- new_buffer = NULL;
- }

- rb_erase(best_fit, &alloc->free_buffers);
+ rb_erase(&buffer->rb_node, &alloc->free_buffers);
buffer->free = 0;
buffer->allow_user_free = 0;
binder_insert_allocated_buffer_locked(alloc, buffer);
--
2.43.0.rc2.451.g8631bc7472-goog