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84c1e51d7d
The current codebase makes use of the zero-length array language
extension to the C90 standard, but the preferred mechanism to declare
variable-length types such as these ones is a flexible array member[1][2],
introduced in C99:
struct foo {
int stuff;
struct boo array[];
};
By making use of the mechanism above, we will get a compiler warning
in case the flexible array does not occur last in the structure, which
will help us prevent some kind of undefined behavior bugs from being
inadvertently introduced[3] to the codebase from now on.
Also, notice that, dynamic memory allocations won't be affected by
this change:
"Flexible array members have incomplete type, and so the sizeof operator
may not be applied. As a quirk of the original implementation of
zero-length arrays, sizeof evaluates to zero."[1]
sizeof(flexible-array-member) triggers a warning because flexible array
members have incomplete type[1]. There are some instances of code in
which the sizeof operator is being incorrectly/erroneously applied to
zero-length arrays and the result is zero. Such instances may be hiding
some bugs. So, this work (flexible-array member conversions) will also
help to get completely rid of those sorts of issues.
This issue was found with the help of Coccinelle.
[1] https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html
[2] https://github.com/KSPP/linux/issues/21
[3] commit 7649773293 ("cxgb3/l2t: Fix undefined behaviour")
Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
Link: https://lore.kernel.org/r/20200507185318.GA14393@embeddedor
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
64 lines
1.3 KiB
C
64 lines
1.3 KiB
C
/* SPDX-License-Identifier: (GPL-2.0 OR BSD-3-Clause) */
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/*
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* Copyright(c) 2016 Google Inc. All rights reserved.
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* Copyright(c) 2016 Linaro Ltd. All rights reserved.
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*/
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#ifndef __ARPC_H
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#define __ARPC_H
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/* APBridgeA RPC (ARPC) */
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enum arpc_result {
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ARPC_SUCCESS = 0x00,
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ARPC_NO_MEMORY = 0x01,
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ARPC_INVALID = 0x02,
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ARPC_TIMEOUT = 0x03,
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ARPC_UNKNOWN_ERROR = 0xff,
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};
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struct arpc_request_message {
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__le16 id; /* RPC unique id */
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__le16 size; /* Size in bytes of header + payload */
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__u8 type; /* RPC type */
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__u8 data[]; /* ARPC data */
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} __packed;
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struct arpc_response_message {
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__le16 id; /* RPC unique id */
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__u8 result; /* Result of RPC */
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} __packed;
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/* ARPC requests */
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#define ARPC_TYPE_CPORT_CONNECTED 0x01
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#define ARPC_TYPE_CPORT_QUIESCE 0x02
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#define ARPC_TYPE_CPORT_CLEAR 0x03
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#define ARPC_TYPE_CPORT_FLUSH 0x04
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#define ARPC_TYPE_CPORT_SHUTDOWN 0x05
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struct arpc_cport_connected_req {
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__le16 cport_id;
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} __packed;
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struct arpc_cport_quiesce_req {
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__le16 cport_id;
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__le16 peer_space;
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__le16 timeout;
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} __packed;
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struct arpc_cport_clear_req {
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__le16 cport_id;
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} __packed;
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struct arpc_cport_flush_req {
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__le16 cport_id;
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} __packed;
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struct arpc_cport_shutdown_req {
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__le16 cport_id;
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__le16 timeout;
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__u8 phase;
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} __packed;
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#endif /* __ARPC_H */
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