diff options
author | Gustavo A. R. Silva <gustavoars@kernel.org> | 2020-05-07 14:21:47 -0500 |
---|---|---|
committer | Martin K. Petersen <martin.petersen@oracle.com> | 2020-05-11 22:26:32 -0400 |
commit | 00b42b70ae521e6ccc86ed403e2d101616689bdc (patch) | |
tree | 3f3ff3ed8080a312322d9c414fcbb47d13f548aa /drivers/scsi/aic94xx | |
parent | f9491ed56e3a73aaa27accf4600671611dcf18bd (diff) | |
download | linux-00b42b70ae521e6ccc86ed403e2d101616689bdc.tar.bz2 |
scsi: libsas: Replace zero-length array with flexible-array
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]
sizeof(flexible-array-member) triggers a warning because flexible array
members have incomplete type[1]. There are some instances of code in which
the sizeof operator is being incorrectly/erroneously applied to zero-length
arrays and the result is zero. Such instances may be hiding some bugs. So,
this work (flexible-array member conversions) will also help to get
completely rid of those sorts of issues.
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/20200507192147.GA16206@embeddedor
Reviewed-by: John Garry <john.garry@huawei.com>
Reviewed-by: Jason Yan <yanaijie@huawei.com>
Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Diffstat (limited to 'drivers/scsi/aic94xx')
-rw-r--r-- | drivers/scsi/aic94xx/aic94xx_sds.c | 14 |
1 files changed, 7 insertions, 7 deletions
diff --git a/drivers/scsi/aic94xx/aic94xx_sds.c b/drivers/scsi/aic94xx/aic94xx_sds.c index 3ddc8852bc32..105adba559a1 100644 --- a/drivers/scsi/aic94xx/aic94xx_sds.c +++ b/drivers/scsi/aic94xx/aic94xx_sds.c @@ -406,7 +406,7 @@ struct asd_manuf_sec { u8 sas_addr[SAS_ADDR_SIZE]; u8 pcba_sn[ASD_PCBA_SN_SIZE]; /* Here start the other segments */ - u8 linked_list[0]; + u8 linked_list[]; } __attribute__ ((packed)); struct asd_manuf_phy_desc { @@ -449,7 +449,7 @@ struct asd_ms_sb_desc { u8 type; u8 node_desc_index; u8 conn_desc_index; - u8 _recvd[0]; + u8 _recvd[]; } __attribute__ ((packed)); #if 0 @@ -478,12 +478,12 @@ struct asd_ms_conn_desc { u8 size_sideband_desc; u32 _resvd; u8 name[16]; - struct asd_ms_sb_desc sb_desc[0]; + struct asd_ms_sb_desc sb_desc[]; } __attribute__ ((packed)); struct asd_nd_phy_desc { u8 vp_attch_type; - u8 attch_specific[0]; + u8 attch_specific[]; } __attribute__ ((packed)); #if 0 @@ -503,7 +503,7 @@ struct asd_ms_node_desc { u8 size_phy_desc; u8 _resvd; u8 name[16]; - struct asd_nd_phy_desc phy_desc[0]; + struct asd_nd_phy_desc phy_desc[]; } __attribute__ ((packed)); struct asd_ms_conn_map { @@ -518,7 +518,7 @@ struct asd_ms_conn_map { u8 usage_model_id; u32 _resvd; struct asd_ms_conn_desc conn_desc[0]; - struct asd_ms_node_desc node_desc[0]; + struct asd_ms_node_desc node_desc[]; } __attribute__ ((packed)); struct asd_ctrla_phy_entry { @@ -542,7 +542,7 @@ struct asd_ll_el { u8 id0; u8 id1; __le16 next; - u8 something_here[0]; + u8 something_here[]; } __attribute__ ((packed)); static int asd_poll_flash(struct asd_ha_struct *asd_ha) |