There is a regular need in the kernel to provide a way to declare having
a dynamically sized set of trailing elements in a structure. Kernel code
should always use “flexible array members”[1] for these cases. The older
style of one-element or zero-length arrays should no longer be used[2].
Also, this helps with the ongoing efforts to enable -Warray-bounds by
fixing the following warning:
CC [M] fs/hpfs/dir.o
fs/hpfs/dir.c: In function ‘hpfs_readdir’:
fs/hpfs/dir.c:163:41: warning: array subscript 1 is above array bounds of ‘u8[1]’ {aka ‘unsigned char[1]’} [-Warray-bounds]
163 | || de ->name[0] != 1 || de->name[1] != 1))
| ~~~~~~~~^~~
[1] https://en.wikipedia.org/wiki/Flexible_array_member
[2] https://www.kernel.org/doc/html/v5.10/process/deprecated.html#zero-length-and-one-element-arrays
Link: https://github.com/KSPP/linux/issues/79
Link: https://github.com/KSPP/linux/issues/109
Signed-off-by: Gustavo A. R. Silva <[email protected]>
---
fs/hpfs/hpfs.h | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/fs/hpfs/hpfs.h b/fs/hpfs/hpfs.h
index 302f45101a96..d92c4af3e1b4 100644
--- a/fs/hpfs/hpfs.h
+++ b/fs/hpfs/hpfs.h
@@ -356,7 +356,8 @@ struct hpfs_dirent {
u8 no_of_acls; /* number of ACL's (low 3 bits) */
u8 ix; /* code page index (of filename), see
struct code_page_data */
- u8 namelen, name[1]; /* file name */
+ u8 namelen; /* file name length */
+ u8 name[]; /* file name */
/* dnode_secno down; btree down pointer, if present,
follows name on next word boundary, or maybe it
precedes next dirent, which is on a word boundary. */
--
2.27.0
Hi all,
Friendly ping: who can take this, please?
Thanks
--
Gustavo
On 3/26/21 12:35, Gustavo A. R. Silva wrote:
> There is a regular need in the kernel to provide a way to declare having
> a dynamically sized set of trailing elements in a structure. Kernel code
> should always use “flexible array members”[1] for these cases. The older
> style of one-element or zero-length arrays should no longer be used[2].
>
> Also, this helps with the ongoing efforts to enable -Warray-bounds by
> fixing the following warning:
>
> CC [M] fs/hpfs/dir.o
> fs/hpfs/dir.c: In function ‘hpfs_readdir’:
> fs/hpfs/dir.c:163:41: warning: array subscript 1 is above array bounds of ‘u8[1]’ {aka ‘unsigned char[1]’} [-Warray-bounds]
> 163 | || de ->name[0] != 1 || de->name[1] != 1))
> | ~~~~~~~~^~~
>
> [1] https://en.wikipedia.org/wiki/Flexible_array_member
> [2] https://www.kernel.org/doc/html/v5.10/process/deprecated.html#zero-length-and-one-element-arrays
>
> Link: https://github.com/KSPP/linux/issues/79
> Link: https://github.com/KSPP/linux/issues/109
> Signed-off-by: Gustavo A. R. Silva <[email protected]>
> ---
> fs/hpfs/hpfs.h | 3 ++-
> 1 file changed, 2 insertions(+), 1 deletion(-)
>
> diff --git a/fs/hpfs/hpfs.h b/fs/hpfs/hpfs.h
> index 302f45101a96..d92c4af3e1b4 100644
> --- a/fs/hpfs/hpfs.h
> +++ b/fs/hpfs/hpfs.h
> @@ -356,7 +356,8 @@ struct hpfs_dirent {
> u8 no_of_acls; /* number of ACL's (low 3 bits) */
> u8 ix; /* code page index (of filename), see
> struct code_page_data */
> - u8 namelen, name[1]; /* file name */
> + u8 namelen; /* file name length */
> + u8 name[]; /* file name */
> /* dnode_secno down; btree down pointer, if present,
> follows name on next word boundary, or maybe it
> precedes next dirent, which is on a word boundary. */
>