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| author | Gustavo A. R. Silva <gustavo@embeddedor.com> | 2020-02-24 19:14:06 +0300 |
|---|---|---|
| committer | Martin K. Petersen <martin.petersen@oracle.com> | 2020-03-12 06:07:56 +0300 |
| commit | 5febf6d6ae4d488a5dc388c46d96c17f9556238f (patch) | |
| tree | 220cb44bf3d7792bc6460d43b06e9a90506d1869 /drivers/scsi/mvsas | |
| parent | 5905d4648e7ec2cc9316b17290f21e8bd8a78c32 (diff) | |
| download | linux-5febf6d6ae4d488a5dc388c46d96c17f9556238f.tar.xz | |
scsi: 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/20200224161406.GA21454@embeddedor
Reviewed-by: Lee Duncan <lduncan@suse.com>
Reviewed-by: Satish Kharat <satishkh@cisco.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/scsi/mvsas')
| -rw-r--r-- | drivers/scsi/mvsas/mv_sas.h | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/drivers/scsi/mvsas/mv_sas.h b/drivers/scsi/mvsas/mv_sas.h index 519edc796691..327fdd5ee962 100644 --- a/drivers/scsi/mvsas/mv_sas.h +++ b/drivers/scsi/mvsas/mv_sas.h @@ -394,7 +394,7 @@ struct mvs_info { dma_addr_t bulk_buffer_dma1; #define TRASH_BUCKET_SIZE 0x20000 void *dma_pool; - struct mvs_slot_info slot_info[0]; + struct mvs_slot_info slot_info[]; }; struct mvs_prv_info{ |