linux-kernel - [PATCH] proc: do mmput ASAP for /proc/*/map

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Message-ID: <20180309223120.GC3843@avx2>
Date:   Sat, 10 Mar 2018 01:31:20 +0300
From:   Alexey Dobriyan <adobriyan@...il.com>
To:     akpm@...ux-foundation.org
Cc:     linux-kernel@...r.kernel.org
Subject: [PATCH] proc: do mmput ASAP for /proc/*/map_files

mm_struct not needed while printing as all the data was already extracted.


Signed-off-by: Alexey Dobriyan <adobriyan@...il.com>
---

 fs/proc/base.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/fs/proc/base.c
+++ b/fs/proc/base.c
@@ -2214,6 +2214,7 @@ proc_map_files_readdir(struct file *file, struct dir_context *ctx)
 		}
 	}
 	up_read(&mm->mmap_sem);
+	mmput(mm);
 
 	for (i = 0; i < nr_files; i++) {
 		char buf[4 * sizeof(long) + 2];	/* max: %lx-%lx\0 */
@@ -2231,7 +2232,6 @@ proc_map_files_readdir(struct file *file, struct dir_context *ctx)
 	}
 	if (fa)
 		flex_array_free(fa);
-	mmput(mm);
 
 out_put_task:
 	put_task_struct(task);