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>
struct vnic_devcmd_provinfo {
u8 oui[3];
u8 type;
- u8 data[0];
+ u8 data[];
};
/*
struct ipr_config_table {
struct ipr_config_table_hdr hdr;
- struct ipr_config_table_entry dev[0];
+ struct ipr_config_table_entry dev[];
}__attribute__((packed, aligned (4)));
struct ipr_config_table64 {
struct ipr_config_table_hdr64 hdr64;
- struct ipr_config_table_entry64 dev[0];
+ struct ipr_config_table_entry64 dev[];
}__attribute__((packed, aligned (8)));
struct ipr_config_table_entry_wrapper {
struct ipr_mode_page_hdr hdr;
u8 num_entries;
u8 entry_length;
- struct ipr_dev_bus_entry bus[0];
+ struct ipr_dev_bus_entry bus[];
}__attribute__((packed));
struct ipr_mode_page24 {
u8 func; /* byte 1 */
u8 alloc_resp_len; /* byte 2 */
u8 req_len; /* byte 3 */
- u8 req_data[0];
+ u8 req_data[];
} __packed;
/*
u8 ignore;
u16 event;
struct kref refcount;
- char event_data[0] __aligned(4);
+ char event_data[] __aligned(4);
};
static void fw_event_work_free(struct kref *r)
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{
struct mvumi_hotplug_event {
u16 size;
u8 dummy[2];
- u8 bitmap[0];
+ u8 bitmap[];
};
struct mvumi_driver_event {
struct mvumi_ob_data {
struct list_head list;
- unsigned char data[0];
+ unsigned char data[];
};
struct version_info {
u32 hostno;
u32 length;
u8 reserved[8];
- u8 data[0];
+ u8 data[];
};
/* Controller state event message type */
struct vnic_devcmd_provinfo {
u8 oui[3];
u8 type;
- u8 data[0];
+ u8 data[];
};
/*
u8 data_dir;
u8 payload_sz; /* payload size in 4-byte, not used */
u8 cdb[STEX_CDB_LENGTH];
- u32 variable[0];
+ u32 variable[];
};
struct status_msg {
struct iscsi_param_info {
uint32_t len; /* Actual length of the param value */
uint16_t param; /* iscsi param */
- uint8_t value[0]; /* length sized value follows */
+ uint8_t value[]; /* length sized value follows */
} __packed;
struct iscsi_iface_param_info {
uint16_t param; /* iscsi param value */
uint8_t iface_type; /* IPv4 or IPv6 */
uint8_t param_type; /* iscsi_param_type */
- uint8_t value[0]; /* length sized value follows */
+ uint8_t value[]; /* length sized value follows */
} __packed;
/*
struct iscsi_flashnode_param_info {
uint32_t len; /* Actual length of the param */
uint16_t param; /* iscsi param value */
- uint8_t value[0]; /* length sized value follows */
+ uint8_t value[]; /* length sized value follows */
} __packed;
enum iscsi_discovery_parent_type {
* up to ISCSI_STATS_CUSTOM_MAX
*/
uint32_t custom_length;
- struct iscsi_stats_custom custom[0]
+ struct iscsi_stats_custom custom[]
__attribute__ ((aligned (sizeof(uint64_t))));
};
* up to ISCSI_HOST_STATS_CUSTOM_MAX
*/
uint32_t custom_length;
- struct iscsi_host_stats_custom custom[0]
+ struct iscsi_host_stats_custom custom[]
__aligned(sizeof(uint64_t));
};
uint64_t vendor_id;
/* start of vendor command area */
- uint32_t vendor_cmd[0];
+ uint32_t vendor_cmd[];
};
/* Response:
struct mutex state_mutex;
enum scsi_device_state sdev_state;
struct task_struct *quiesced_by;
- unsigned long sdev_data[0];
+ unsigned long sdev_data[];
} __attribute__((aligned(sizeof(unsigned long))));
#define to_scsi_device(d) \
char scsi_level;
enum scsi_target_state state;
void *hostdata; /* available to low-level driver */
- unsigned long starget_data[0]; /* for the transport */
+ unsigned long starget_data[]; /* for the transport */
/* starget_data must be the last element!!!! */
} __attribute__((aligned(sizeof(unsigned long))));
* and also because some compilers (m68k) don't automatically force
* alignment to a long boundary.
*/
- unsigned long hostdata[0] /* Used for storage of host specific stuff */
+ unsigned long hostdata[] /* Used for storage of host specific stuff */
__attribute__ ((aligned (sizeof(unsigned long))));
};
typedef struct scsi_ioctl_command {
unsigned int inlen;
unsigned int outlen;
- unsigned char data[0];
+ unsigned char data[];
} Scsi_Ioctl_Command;
typedef struct scsi_idlun {
struct srp_indirect_buf {
struct srp_direct_buf table_desc;
__be32 len;
- struct srp_direct_buf desc_list[0];
+ struct srp_direct_buf desc_list[];
} __attribute__((packed));
/* Immediate data buffer descriptor as defined in SRP2. */
u8 reserved4;
u8 add_cdb_len;
u8 cdb[16];
- u8 add_data[0];
+ u8 add_data[];
};
enum {
__be32 data_in_res_cnt;
__be32 sense_data_len;
__be32 resp_data_len;
- u8 data[0];
+ u8 data[];
} __attribute__((packed));
struct srp_cred_req {
struct scsi_lun lun;
__be32 sense_data_len;
u32 reserved3;
- u8 sense_data[0];
+ u8 sense_data[];
} __attribute__((packed));
struct srp_aer_rsp {
__u64 vendor_id;
/* start of vendor command area */
- __u32 vendor_cmd[0];
+ __u32 vendor_cmd[];
};
/* Response:
git.samba.org / sfrench / cifs-2.6.git / commitdiff