* [PATCH] thunderbolt: icm: Replace zero-length array with flexible-array member
@ 2020-02-11 23:20 Gustavo A. R. Silva
2020-02-14 12:11 ` Mika Westerberg
0 siblings, 1 reply; 2+ messages in thread
From: Gustavo A. R. Silva @ 2020-02-11 23:20 UTC (permalink / raw)
To: Andreas Noever, Michael Jamet, Mika Westerberg, Yehezkel Bernat
Cc: linux-kernel, Gustavo A. R. Silva
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
inadvertenly introduced[3] to the codebase from now on.
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>
---
drivers/thunderbolt/icm.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/thunderbolt/icm.c b/drivers/thunderbolt/icm.c
index e3fc920af682..3eb0501c3875 100644
--- a/drivers/thunderbolt/icm.c
+++ b/drivers/thunderbolt/icm.c
@@ -100,7 +100,7 @@ struct icm_notification {
struct ep_name_entry {
u8 len;
u8 type;
- u8 data[0];
+ u8 data[];
};
#define EP_NAME_INTEL_VSS 0x10
--
2.25.0
^ permalink raw reply related [flat|nested] 2+ messages in thread
* Re: [PATCH] thunderbolt: icm: Replace zero-length array with flexible-array member
2020-02-11 23:20 [PATCH] thunderbolt: icm: Replace zero-length array with flexible-array member Gustavo A. R. Silva
@ 2020-02-14 12:11 ` Mika Westerberg
0 siblings, 0 replies; 2+ messages in thread
From: Mika Westerberg @ 2020-02-14 12:11 UTC (permalink / raw)
To: Gustavo A. R. Silva
Cc: Andreas Noever, Michael Jamet, Yehezkel Bernat, linux-kernel
On Tue, Feb 11, 2020 at 05:20:09PM -0600, Gustavo A. R. Silva wrote:
> 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
> inadvertenly introduced[3] to the codebase from now on.
>
> 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>
Applied, thanks!
^ permalink raw reply [flat|nested] 2+ messages in thread
end of thread, other threads:[~2020-02-14 12:11 UTC | newest]
Thread overview: 2+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2020-02-11 23:20 [PATCH] thunderbolt: icm: Replace zero-length array with flexible-array member Gustavo A. R. Silva
2020-02-14 12:11 ` Mika Westerberg
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).