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From: Stefan Metzmacher <[email protected]>
To: [email protected]
Cc: Stefan Metzmacher <[email protected]>
Subject: [PATCH] io_uring: add BUILD_BUG_ON() to assert the layout of struct io_uring_sqe
Date: Wed, 29 Jan 2020 14:39:41 +0100	[thread overview]
Message-ID: <[email protected]> (raw)
In-Reply-To: <[email protected]>

With nesting of anonymous unions and structs it's hard to
review layout changes. It's better to ask the compiler
for these things.

Signed-off-by: Stefan Metzmacher <[email protected]>
---
 fs/io_uring.c | 33 +++++++++++++++++++++++++++++++++
 1 file changed, 33 insertions(+)

diff --git a/fs/io_uring.c b/fs/io_uring.c
index 9479b5481ad2..b31523f4db6e 100644
--- a/fs/io_uring.c
+++ b/fs/io_uring.c
@@ -6882,6 +6882,39 @@ SYSCALL_DEFINE4(io_uring_register, unsigned int, fd, unsigned int, opcode,
 
 static int __init io_uring_init(void)
 {
+#define __BUILD_BUG_VERIFY_ELEMENT(stype, eoffset, etype, ename) do { \
+	BUILD_BUG_ON(offsetof(stype, ename) != eoffset); \
+	BUILD_BUG_ON(sizeof(etype) != sizeof_field(stype, ename)); \
+} while (0)
+
+#define BUILD_BUG_SQE_ELEM(eoffset, etype, ename) \
+	__BUILD_BUG_VERIFY_ELEMENT(struct io_uring_sqe, eoffset, etype, ename)
+	BUILD_BUG_ON(sizeof(struct io_uring_sqe) != 64);
+	BUILD_BUG_SQE_ELEM(0,  __u8,   opcode);
+	BUILD_BUG_SQE_ELEM(1,  __u8,   flags);
+	BUILD_BUG_SQE_ELEM(2,  __u16,  ioprio);
+	BUILD_BUG_SQE_ELEM(4,  __s32,  fd);
+	BUILD_BUG_SQE_ELEM(8,  __u64,  off);
+	BUILD_BUG_SQE_ELEM(8,  __u64,  addr2);
+	BUILD_BUG_SQE_ELEM(16, __u64,  addr);
+	BUILD_BUG_SQE_ELEM(24, __u32,  len);
+	BUILD_BUG_SQE_ELEM(28,     __kernel_rwf_t, rw_flags);
+	BUILD_BUG_SQE_ELEM(28, /* compat */   int, rw_flags);
+	BUILD_BUG_SQE_ELEM(28, /* compat */ __u32, rw_flags);
+	BUILD_BUG_SQE_ELEM(28, __u32,  fsync_flags);
+	BUILD_BUG_SQE_ELEM(28, __u16,  poll_events);
+	BUILD_BUG_SQE_ELEM(28, __u32,  sync_range_flags);
+	BUILD_BUG_SQE_ELEM(28, __u32,  msg_flags);
+	BUILD_BUG_SQE_ELEM(28, __u32,  timeout_flags);
+	BUILD_BUG_SQE_ELEM(28, __u32,  accept_flags);
+	BUILD_BUG_SQE_ELEM(28, __u32,  cancel_flags);
+	BUILD_BUG_SQE_ELEM(28, __u32,  open_flags);
+	BUILD_BUG_SQE_ELEM(28, __u32,  statx_flags);
+	BUILD_BUG_SQE_ELEM(28, __u32,  fadvise_advice);
+	BUILD_BUG_SQE_ELEM(32, __u64,  user_data);
+	BUILD_BUG_SQE_ELEM(40, __u16,  buf_index);
+	BUILD_BUG_SQE_ELEM(42, __u16,  personality);
+
 	BUILD_BUG_ON(ARRAY_SIZE(io_op_defs) != IORING_OP_LAST);
 	req_cachep = KMEM_CACHE(io_kiocb, SLAB_HWCACHE_ALIGN | SLAB_PANIC);
 	return 0;
-- 
2.17.1


  reply	other threads:[~2020-01-29 13:40 UTC|newest]

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-01-29 13:22 [PATCH] io_uring: add BUILD_BUG_ON() to assert the layout of struct io_uring_sqe Stefan Metzmacher
2020-01-29 13:39 ` Stefan Metzmacher [this message]
2020-01-30 15:51   ` Jens Axboe
2020-01-30 16:01     ` Stefan Metzmacher
2020-01-30 16:06       ` Jens Axboe

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