From addebd9ac9ca0ef8b3764907bf8018e48caffc64 Mon Sep 17 00:00:00 2001
From: Keith Busch <kbusch@kernel.org>
Date: Fri, 12 Aug 2022 15:56:33 -0700
Subject: [PATCH] fs: don't randomize struct kiocb fields
This is a size sensitive structure and randomizing can introduce extra
padding that breaks io_uring's fixed size expectations. There are few
fields here as it is, half of which need a fixed order to optimally
pack, so the randomization isn't providing much.
Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Keith Busch <kbusch@kernel.org>
Link: https://lore.kernel.org/io-uring/b6f508ca-b1b2-5f40-7998-e4cff1cf7212@kernel.dk/
Signed-off-by: Jens Axboe <axboe@kernel.dk>
---
include/linux/fs.h | 5 -----
1 file changed, 5 deletions(-)
diff --git a/include/linux/fs.h b/include/linux/fs.h
index 9f131e559d05d..daf69a6504b6c 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -339,17 +339,12 @@ enum rw_hint {
struct kiocb {
struct file *ki_filp;
-
- /* The 'ki_filp' pointer is shared in a union for aio */
- randomized_struct_fields_start
-
loff_t ki_pos;
void (*ki_complete)(struct kiocb *iocb, long ret);
void *private;
int ki_flags;
u16 ki_ioprio; /* See linux/ioprio.h */
struct wait_page_queue *ki_waitq; /* for async buffered IO */
- randomized_struct_fields_end
};
static inline bool is_sync_kiocb(struct kiocb *kiocb)
--
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