diff options
| author | Gustavo A. R. Silva | 2020-03-19 18:10:58 -0500 |
|---|---|---|
| committer | Rob Herring | 2020-03-31 09:03:34 -0600 |
| commit | f43775625e28703469198657392168c5fe961edc (patch) | |
| tree | 6f9ad20db9d72c1495acfc01a8c9297ce2ac7786 | |
| parent | e64ca27ab9205b993dc5aa7a1ad1d093f1b9ab76 (diff) | |
of: of_private.h: 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: Rob Herring <robh@kernel.org>
| -rw-r--r-- | drivers/of/of_private.h | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/drivers/of/of_private.h b/drivers/of/of_private.h index 207863c151a5..edc682249c00 100644 --- a/drivers/of/of_private.h +++ b/drivers/of/of_private.h @@ -24,7 +24,7 @@ struct alias_prop { const char *alias; struct device_node *np; int id; - char stem[0]; + char stem[]; }; #if defined(CONFIG_SPARC) |