diff options
| author | Gustavo A. R. Silva <gustavo@embeddedor.com> | 2020-03-23 19:38:18 -0500 |
|---|---|---|
| committer | Gustavo A. R. Silva <gustavo@embeddedor.com> | 2020-04-18 15:44:56 -0500 |
| commit | 06ccf63da5d8e90e4dff8b741972a9b279b5bf4c (patch) | |
| tree | f0fe16b5642573e5216d51952511b620b372c287 /include | |
| parent | 4ea19ecf322c2f98ef87fc980b3851625b082ac2 (diff) | |
tpm_eventlog.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>
Diffstat (limited to 'include')
| -rw-r--r-- | include/linux/tpm_eventlog.h | 6 |
1 files changed, 3 insertions, 3 deletions
diff --git a/include/linux/tpm_eventlog.h b/include/linux/tpm_eventlog.h index 131ea1bad458..c253461b1c4e 100644 --- a/include/linux/tpm_eventlog.h +++ b/include/linux/tpm_eventlog.h @@ -28,7 +28,7 @@ struct tcpa_event { u32 event_type; u8 pcr_value[20]; /* SHA1 */ u32 event_size; - u8 event_data[0]; + u8 event_data[]; }; enum tcpa_event_types { @@ -55,7 +55,7 @@ enum tcpa_event_types { struct tcpa_pc_event { u32 event_id; u32 event_size; - u8 event_data[0]; + u8 event_data[]; }; enum tcpa_pc_event_ids { @@ -102,7 +102,7 @@ struct tcg_pcr_event { struct tcg_event_field { u32 event_size; - u8 event[0]; + u8 event[]; } __packed; struct tcg_pcr_event2_head { |