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| author | Gustavo A. R. Silva <gustavo@embeddedor.com> | 2020-02-13 03:02:11 +0300 |
|---|---|---|
| committer | Martin K. Petersen <martin.petersen@oracle.com> | 2020-02-18 08:39:54 +0300 |
| commit | b417107a659e9745f9ff905196ddff70cbe4eaa7 (patch) | |
| tree | 4b3e1d02553c168aa65b313435f1cccbe4ce0574 /drivers/scsi/advansys.c | |
| parent | df3fe76658ed47617741819a501e2bd2ae446962 (diff) | |
| download | linux-b417107a659e9745f9ff905196ddff70cbe4eaa7.tar.xz | |
scsi: advansys: 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/20200213000211.GA23171@embeddedor.com
Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Diffstat (limited to 'drivers/scsi/advansys.c')
| -rw-r--r-- | drivers/scsi/advansys.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/drivers/scsi/advansys.c b/drivers/scsi/advansys.c index a242a62caaa1..c2c7850ff7b4 100644 --- a/drivers/scsi/advansys.c +++ b/drivers/scsi/advansys.c @@ -316,7 +316,7 @@ typedef struct asc_sg_head { ushort queue_cnt; ushort entry_to_copy; ushort res; - ASC_SG_LIST sg_list[0]; + ASC_SG_LIST sg_list[]; } ASC_SG_HEAD; typedef struct asc_scsi_q { |