| Message ID | 20200224161406.GA21454@embeddedor (mailing list archive) |
|---|---|
| State | Not Applicable |
| Headers | show |
| Series | scsi: Replace zero-length array with flexible-array member | expand |
On 2/24/20 8:14 AM, Gustavo A. R. Silva wrote: > 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@embeddedor.com> > --- > ... > 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: > Reviewed-by: Lee Duncan <lduncan@suse.com>
On 2/24/20 10:30, Lee Duncan wrote: > On 2/24/20 8:14 AM, Gustavo A. R. Silva wrote: >> 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@embeddedor.com> >> --- >> ... >> 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: >> > > Reviewed-by: Lee Duncan <lduncan@suse.com> > Thanks, Lee. -- Gustavo
Gustavo, > 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: Applied to 5.7/scsi-queue, thanks.
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:
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@embeddedor.com> --- 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(-)