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| author | Gustavo A. R. Silva <gustavo@embeddedor.com> | 2020-03-20 01:25:33 +0300 |
|---|---|---|
| committer | Martin K. Petersen <martin.petersen@oracle.com> | 2020-03-27 05:40:47 +0300 |
| commit | fd6282af8ebd92a32d0b877efb28a3f3272fbed0 (patch) | |
| tree | ac995316cd4257d140c520ad75ca5f5d5391eea4 /drivers/message | |
| parent | 4f93c4bf0f748f9d0f5e9764ba69ec16c368922a (diff) | |
| download | linux-fd6282af8ebd92a32d0b877efb28a3f3272fbed0.tar.xz | |
scsi: message: fusion: 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")
Link: https://lore.kernel.org/r/20200319222533.GA20577@embeddedor.com
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Diffstat (limited to 'drivers/message')
| -rw-r--r-- | drivers/message/fusion/mptsas.h | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/drivers/message/fusion/mptsas.h b/drivers/message/fusion/mptsas.h index c396483d3624..e35b13891fe4 100644 --- a/drivers/message/fusion/mptsas.h +++ b/drivers/message/fusion/mptsas.h @@ -110,7 +110,7 @@ struct fw_event_work { MPT_ADAPTER *ioc; u32 event; u8 retries; - char event_data[0] __aligned(4); + char event_data[] __aligned(4); }; struct mptsas_discovery_event { |