path: root/net/dccp/ccid.h
diff options
authorGustavo A. R. Silva <gustavo@embeddedor.com>2020-02-28 07:33:37 -0600
committerDavid S. Miller <davem@davemloft.net>2020-02-28 12:08:37 -0800
commit8402a31dd803e091fd2ec9cd22040b34a0b07085 (patch)
tree05be3234ff3267189e4b73c36906e234352655a3 /net/dccp/ccid.h
parentl2tp: Replace zero-length array with flexible-array member (diff)
net: dccp: Replace zero-length array with flexible-array member
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] 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 76497732932f ("cxgb3/l2t: Fix undefined behaviour") Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/dccp/ccid.h')
1 files changed, 1 insertions, 1 deletions
diff --git a/net/dccp/ccid.h b/net/dccp/ccid.h
index 70f88f2b4456..105f3734dadb 100644
--- a/net/dccp/ccid.h
+++ b/net/dccp/ccid.h
@@ -95,7 +95,7 @@ void ccid_cleanup_builtins(void);
struct ccid {
struct ccid_operations *ccid_ops;
- char ccid_priv[0];
+ char ccid_priv[];
static inline void *ccid_priv(const struct ccid *ccid)