[PATCH] scsi: Replace zero-length array with flexible-array member
From: Gustavo A. R. Silva
Date: Mon Feb 24 2020 - 11:33:13 EST
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")
Signed-off-by: Gustavo A. R. Silva <gustavo@xxxxxxxxxxxxxx>
---
drivers/scsi/fnic/vnic_devcmd.h | 2 +-
drivers/scsi/ipr.h | 6 +++---
drivers/scsi/isci/sas.h | 2 +-
drivers/scsi/mpt3sas/mpt3sas_scsih.c | 2 +-
drivers/scsi/mvsas/mv_sas.h | 2 +-
drivers/scsi/mvumi.h | 4 ++--
drivers/scsi/pmcraid.h | 2 +-
drivers/scsi/snic/vnic_devcmd.h | 2 +-
drivers/scsi/stex.c | 2 +-
include/scsi/iscsi_if.h | 10 +++++-----
include/scsi/scsi_bsg_iscsi.h | 2 +-
include/scsi/scsi_device.h | 4 ++--
include/scsi/scsi_host.h | 2 +-
include/scsi/scsi_ioctl.h | 2 +-
include/scsi/srp.h | 8 ++++----
include/uapi/scsi/scsi_bsg_fc.h | 2 +-
16 files changed, 27 insertions(+), 27 deletions(-)
diff --git a/drivers/scsi/fnic/vnic_devcmd.h b/drivers/scsi/fnic/vnic_devcmd.h
index c5dde556dc7c..c20d30e36dfc 100644
--- a/drivers/scsi/fnic/vnic_devcmd.h
+++ b/drivers/scsi/fnic/vnic_devcmd.h
@@ -442,7 +442,7 @@ struct vnic_devcmd_notify {
struct vnic_devcmd_provinfo {
u8 oui[3];
u8 type;
- u8 data[0];
+ u8 data[];
};
/*
diff --git a/drivers/scsi/ipr.h b/drivers/scsi/ipr.h
index a67baeb36d1f..fd3929a19ab5 100644
--- a/drivers/scsi/ipr.h
+++ b/drivers/scsi/ipr.h
@@ -451,12 +451,12 @@ struct ipr_config_table_hdr64 {
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 {
@@ -792,7 +792,7 @@ struct ipr_mode_page28 {
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 {
diff --git a/drivers/scsi/isci/sas.h b/drivers/scsi/isci/sas.h
index dc26b4aea99e..15d8f3631ab7 100644
--- a/drivers/scsi/isci/sas.h
+++ b/drivers/scsi/isci/sas.h
@@ -201,7 +201,7 @@ struct smp_req {
u8 func; /* byte 1 */
u8 alloc_resp_len; /* byte 2 */
u8 req_len; /* byte 3 */
- u8 req_data[0];
+ u8 req_data[];
} __packed;
/*
diff --git a/drivers/scsi/mpt3sas/mpt3sas_scsih.c b/drivers/scsi/mpt3sas/mpt3sas_scsih.c
index c597d544eb39..778d5e6ce385 100644
--- a/drivers/scsi/mpt3sas/mpt3sas_scsih.c
+++ b/drivers/scsi/mpt3sas/mpt3sas_scsih.c
@@ -207,7 +207,7 @@ struct fw_event_work {
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)
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{
diff --git a/drivers/scsi/mvumi.h b/drivers/scsi/mvumi.h
index ec8cc2207536..60d5691fc4ab 100644
--- a/drivers/scsi/mvumi.h
+++ b/drivers/scsi/mvumi.h
@@ -130,7 +130,7 @@ enum {
struct mvumi_hotplug_event {
u16 size;
u8 dummy[2];
- u8 bitmap[0];
+ u8 bitmap[];
};
struct mvumi_driver_event {
@@ -290,7 +290,7 @@ struct mvumi_rsp_frame {
struct mvumi_ob_data {
struct list_head list;
- unsigned char data[0];
+ unsigned char data[];
};
struct version_info {
diff --git a/drivers/scsi/pmcraid.h b/drivers/scsi/pmcraid.h
index a4f7eb8f50a3..15c962108075 100644
--- a/drivers/scsi/pmcraid.h
+++ b/drivers/scsi/pmcraid.h
@@ -623,7 +623,7 @@ struct pmcraid_aen_msg {
u32 hostno;
u32 length;
u8 reserved[8];
- u8 data[0];
+ u8 data[];
};
/* Controller state event message type */
diff --git a/drivers/scsi/snic/vnic_devcmd.h b/drivers/scsi/snic/vnic_devcmd.h
index d81b4f0ceaaa..0e0fa38f8d90 100644
--- a/drivers/scsi/snic/vnic_devcmd.h
+++ b/drivers/scsi/snic/vnic_devcmd.h
@@ -208,7 +208,7 @@ struct vnic_devcmd_notify {
struct vnic_devcmd_provinfo {
u8 oui[3];
u8 type;
- u8 data[0];
+ u8 data[];
};
/*
diff --git a/drivers/scsi/stex.c b/drivers/scsi/stex.c
index 33287b6bdf0e..d4f10c0d813c 100644
--- a/drivers/scsi/stex.c
+++ b/drivers/scsi/stex.c
@@ -236,7 +236,7 @@ struct req_msg {
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 {
diff --git a/include/scsi/iscsi_if.h b/include/scsi/iscsi_if.h
index 92b11c7e0b4f..b0e240b10bf9 100644
--- a/include/scsi/iscsi_if.h
+++ b/include/scsi/iscsi_if.h
@@ -311,7 +311,7 @@ enum iscsi_param_type {
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 {
@@ -320,7 +320,7 @@ 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;
/*
@@ -697,7 +697,7 @@ enum iscsi_flashnode_param {
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 {
@@ -815,7 +815,7 @@ struct iscsi_stats {
* 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))));
};
@@ -946,7 +946,7 @@ struct iscsi_offload_host_stats {
* 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));
};
diff --git a/include/scsi/scsi_bsg_iscsi.h b/include/scsi/scsi_bsg_iscsi.h
index fa0c820a1663..6b8128005af8 100644
--- a/include/scsi/scsi_bsg_iscsi.h
+++ b/include/scsi/scsi_bsg_iscsi.h
@@ -52,7 +52,7 @@ struct iscsi_bsg_host_vendor {
uint64_t vendor_id;
/* start of vendor command area */
- uint32_t vendor_cmd[0];
+ uint32_t vendor_cmd[];
};
/* Response:
diff --git a/include/scsi/scsi_device.h b/include/scsi/scsi_device.h
index f8312a3e5b42..4dc158cf09b8 100644
--- a/include/scsi/scsi_device.h
+++ b/include/scsi/scsi_device.h
@@ -231,7 +231,7 @@ struct scsi_device {
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) \
@@ -315,7 +315,7 @@ struct scsi_target {
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))));
diff --git a/include/scsi/scsi_host.h b/include/scsi/scsi_host.h
index 7a97fb8104cf..e6811ea8f984 100644
--- a/include/scsi/scsi_host.h
+++ b/include/scsi/scsi_host.h
@@ -682,7 +682,7 @@ struct Scsi_Host {
* 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))));
};
diff --git a/include/scsi/scsi_ioctl.h b/include/scsi/scsi_ioctl.h
index 4fe69d863b5d..b465799f4d2d 100644
--- a/include/scsi/scsi_ioctl.h
+++ b/include/scsi/scsi_ioctl.h
@@ -27,7 +27,7 @@ struct scsi_device;
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 {
diff --git a/include/scsi/srp.h b/include/scsi/srp.h
index 9220758d5087..177d8026e96f 100644
--- a/include/scsi/srp.h
+++ b/include/scsi/srp.h
@@ -109,7 +109,7 @@ struct srp_direct_buf {
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. */
@@ -244,7 +244,7 @@ struct srp_cmd {
u8 reserved4;
u8 add_cdb_len;
u8 cdb[16];
- u8 add_data[0];
+ u8 add_data[];
};
enum {
@@ -274,7 +274,7 @@ struct srp_rsp {
__be32 data_in_res_cnt;
__be32 sense_data_len;
__be32 resp_data_len;
- u8 data[0];
+ u8 data[];
} __attribute__((packed));
struct srp_cred_req {
@@ -306,7 +306,7 @@ struct srp_aer_req {
struct scsi_lun lun;
__be32 sense_data_len;
u32 reserved3;
- u8 sense_data[0];
+ u8 sense_data[];
} __attribute__((packed));
struct srp_aer_rsp {
diff --git a/include/uapi/scsi/scsi_bsg_fc.h b/include/uapi/scsi/scsi_bsg_fc.h
index 3ae65e93235c..7f5930801f72 100644
--- a/include/uapi/scsi/scsi_bsg_fc.h
+++ b/include/uapi/scsi/scsi_bsg_fc.h
@@ -209,7 +209,7 @@ struct fc_bsg_host_vendor {
__u64 vendor_id;
/* start of vendor command area */
- __u32 vendor_cmd[0];
+ __u32 vendor_cmd[];
};
/* Response:
--
2.25.0