The patch titled Subject: ocfs2: cluster: replace zero-length array with flexible-array member has been removed from the -mm tree. Its filename was ocfs2-cluster-replace-zero-length-array-with-flexible-array-member.patch This patch was dropped because it was merged into mainline or a subsystem tree ------------------------------------------------------ From: "Gustavo A. R. Silva" <gustavo@xxxxxxxxxxxxxx> Subject: ocfs2: cluster: 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://urldefense.com/v3/__https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html__;!!GqivPVa7Brio!NzMr-YRl2zy-K3lwLVVatz7x0uD2z7-ykQag4GrGigxmfWU8TWzDy6xrkTiW3hYl00czlw$ [2] https://urldefense.com/v3/__https://github.com/KSPP/linux/issues/21__;!!GqivPVa7Brio!NzMr-YRl2zy-K3lwLVVatz7x0uD2z7-ykQag4GrGigxmfWU8TWzDy6xrkTiW3hYHG1nAnw$ [3] commit 76497732932f ("cxgb3/l2t: Fix undefined behaviour") Link: http://lkml.kernel.org/r/20200309201907.GA8005@embeddedor Signed-off-by: Gustavo A. R. Silva <gustavo@xxxxxxxxxxxxxx> Acked-by: Joseph Qi <joseph.qi@xxxxxxxxxxxxxxxxx> Cc: Mark Fasheh <mark@xxxxxxxxxx> Cc: Joel Becker <jlbec@xxxxxxxxxxxx> Cc: Junxiao Bi <junxiao.bi@xxxxxxxxxx> Cc: Changwei Ge <gechangwei@xxxxxxx> Cc: Gang He <ghe@xxxxxxxx> Cc: Jun Piao <piaojun@xxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- fs/ocfs2/cluster/tcp.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/fs/ocfs2/cluster/tcp.h~ocfs2-cluster-replace-zero-length-array-with-flexible-array-member +++ a/fs/ocfs2/cluster/tcp.h @@ -32,7 +32,7 @@ struct o2net_msg __be32 status; __be32 key; __be32 msg_num; - __u8 buf[0]; + __u8 buf[]; }; typedef int (o2net_msg_handler_func)(struct o2net_msg *msg, u32 len, void *data, _ Patches currently in -mm which might be from gustavo@xxxxxxxxxxxxxx are lib-bch-replace-zero-length-array-with-flexible-array-member.patch lib-ts_bm-replace-zero-length-array-with-flexible-array-member.patch lib-ts_fsm-replace-zero-length-array-with-flexible-array-member.patch lib-ts_kmp-replace-zero-length-array-with-flexible-array-member.patch gcov-gcc_4_7-replace-zero-length-array-with-flexible-array-member.patch gcov-gcc_3_4-replace-zero-length-array-with-flexible-array-member.patch gcov-fs-replace-zero-length-array-with-flexible-array-member.patch