linux-kernel - [PATCH] binder: Remove incorrect comment about vm_insert

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Message-Id: <20191018153946.128584-1-jannh@google.com>
Date:   Fri, 18 Oct 2019 17:39:46 +0200
From:   Jann Horn <jannh@...gle.com>
To:     Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        "Arve Hjønnevåg" <arve@...roid.com>,
        Todd Kjos <tkjos@...roid.com>,
        Martijn Coenen <maco@...roid.com>,
        Joel Fernandes <joel@...lfernandes.org>,
        Christian Brauner <christian@...uner.io>, jannh@...gle.com
Cc:     devel@...verdev.osuosl.org, linux-kernel@...r.kernel.org
Subject: [PATCH] binder: Remove incorrect comment about vm_insert_page() behavior

vm_insert_page() does increment the page refcount, and just to be sure,
I've confirmed it by printing page_count(page[0].page_ptr) before and after
vm_insert_page(). It's 1 before, 2 afterwards, as expected.

Signed-off-by: Jann Horn <jannh@...gle.com>
---
 drivers/android/binder_alloc.c | 1 -
 1 file changed, 1 deletion(-)

diff --git a/drivers/android/binder_alloc.c b/drivers/android/binder_alloc.c
index d42a8b2f636a..2faada3e97fd 100644
--- a/drivers/android/binder_alloc.c
+++ b/drivers/android/binder_alloc.c
@@ -267,7 +267,6 @@ static int binder_update_page_range(struct binder_alloc *alloc, int allocate,
 			alloc->pages_high = index + 1;
 
 		trace_binder_alloc_page_end(alloc, index);
-		/* vm_insert_page does not seem to increment the refcount */
 	}
 	if (mm) {
 		up_read(&mm->mmap_sem);
-- 
2.23.0.866.gb869b98d4c-goog