overflow: Add struct_size_t() helper

While struct_size() is normally used in situations where the structure
type already has a pointer instance, there are places where no variable
is available. In the past, this has been worked around by using a typed
NULL first argument, but this is a bit ugly. Add a helper to do this,
and replace the handful of instances of the code pattern with it.

Instances were found with this Coccinelle script:

@struct_size_t@
identifier STRUCT, MEMBER;
expression COUNT;
@@

-       struct_size((struct STRUCT *)\(0\|NULL\),
+       struct_size_t(struct STRUCT,
                MEMBER, COUNT)

Suggested-by: Christoph Hellwig <[email protected]>
Cc: Jesse Brandeburg <[email protected]>
Cc: Tony Nguyen <[email protected]>
Cc: "David S. Miller" <[email protected]>
Cc: Eric Dumazet <[email protected]>
Cc: Paolo Abeni <[email protected]>
Cc: James Smart <[email protected]>
Cc: Keith Busch <[email protected]>
Cc: Jens Axboe <[email protected]>
Cc: Sagi Grimberg <[email protected]>
Cc: HighPoint Linux Team <[email protected]>
Cc: "James E.J. Bottomley" <[email protected]>
Cc: "Martin K. Petersen" <[email protected]>
Cc: Kashyap Desai <[email protected]>
Cc: Sumit Saxena <[email protected]>
Cc: Shivasharan S <[email protected]>
Cc: Don Brace <[email protected]>
Cc: "Darrick J. Wong" <[email protected]>
Cc: Dave Chinner <[email protected]>
Cc: Guo Xuenan <[email protected]>
Cc: Gwan-gyeong Mun <[email protected]>
Cc: Nick Desaulniers <[email protected]>
Cc: Daniel Latypov <[email protected]>
Cc: kernel test robot <[email protected]>
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Signed-off-by: Kees Cook <[email protected]>
Acked-by: Martin K. Petersen <[email protected]>
Reviewed-by: Darrick J. Wong <[email protected]>
Reviewed-by: Gustavo A. R. Silva <[email protected]>
Reviewed-by: Christoph Hellwig <[email protected]>
Acked-by: Jakub Kicinski <[email protected]>
Reviewed-by: Alexander Lobakin <[email protected]>
Link: https://lore.kernel.org/r/[email protected]

diff --git a/drivers/net/ethernet/intel/ice/ice_ddp.h b/drivers/net/ethernet/intel/ice/ice_ddp.h
index 37eadb3d27a86271cd6391328af18a717e1d81df..41acfe26df1c6b6f27e4a6ca96f1d162d9188932 100644 (file)
--- a/drivers/net/ethernet/intel/ice/ice_ddp.h
+++ b/drivers/net/ethernet/intel/ice/ice_ddp.h
@@ -185,7 +185,7 @@ struct ice_buf_hdr {
 
 #define ICE_MAX_ENTRIES_IN_BUF(hd_sz, ent_sz)                                 \
        ((ICE_PKG_BUF_SIZE -                                                  \
-         struct_size((struct ice_buf_hdr *)0, section_entry, 1) - (hd_sz)) / \
+         struct_size_t(struct ice_buf_hdr,  section_entry, 1) - (hd_sz)) / \
         (ent_sz))
 
 /* ice package section IDs */
@@ -297,7 +297,7 @@ struct ice_label_section {
 };
 
 #define ICE_MAX_LABELS_IN_BUF                                             \
-       ICE_MAX_ENTRIES_IN_BUF(struct_size((struct ice_label_section *)0, \
+       ICE_MAX_ENTRIES_IN_BUF(struct_size_t(struct ice_label_section,  \
                                           label, 1) -                    \
                                       sizeof(struct ice_label),          \
                               sizeof(struct ice_label))
@@ -352,7 +352,7 @@ struct ice_boost_tcam_section {
 };
 
 #define ICE_MAX_BST_TCAMS_IN_BUF                                               \
-       ICE_MAX_ENTRIES_IN_BUF(struct_size((struct ice_boost_tcam_section *)0, \
+       ICE_MAX_ENTRIES_IN_BUF(struct_size_t(struct ice_boost_tcam_section,  \
                                           tcam, 1) -                          \
                                       sizeof(struct ice_boost_tcam_entry),    \
                               sizeof(struct ice_boost_tcam_entry))
@@ -372,8 +372,7 @@ struct ice_marker_ptype_tcam_section {
 };
 
 #define ICE_MAX_MARKER_PTYPE_TCAMS_IN_BUF                                    \
-       ICE_MAX_ENTRIES_IN_BUF(                                              \
-               struct_size((struct ice_marker_ptype_tcam_section *)0, tcam, \
+       ICE_MAX_ENTRIES_IN_BUF(struct_size_t(struct ice_marker_ptype_tcam_section,  tcam, \
                            1) -                                             \
                        sizeof(struct ice_marker_ptype_tcam_entry),          \
                sizeof(struct ice_marker_ptype_tcam_entry))

diff --git a/drivers/nvme/host/fc.c b/drivers/nvme/host/fc.c
index 2ed75923507dab39e6e1aef5404c8c425bc9261b..691f2df574ce9ff0966ac5b03139f95e68a0d5f4 100644 (file)
--- a/drivers/nvme/host/fc.c
+++ b/drivers/nvme/host/fc.c
@@ -2917,8 +2917,8 @@ nvme_fc_create_io_queues(struct nvme_fc_ctrl *ctrl)
 
        ret = nvme_alloc_io_tag_set(&ctrl->ctrl, &ctrl->tag_set,
                        &nvme_fc_mq_ops, 1,
-                       struct_size((struct nvme_fcp_op_w_sgl *)NULL, priv,
-                                   ctrl->lport->ops->fcprqst_priv_sz));
+                       struct_size_t(struct nvme_fcp_op_w_sgl, priv,
+                                     ctrl->lport->ops->fcprqst_priv_sz));
        if (ret)
                return ret;
 
@@ -3536,8 +3536,8 @@ nvme_fc_init_ctrl(struct device *dev, struct nvmf_ctrl_options *opts,
 
        ret = nvme_alloc_admin_tag_set(&ctrl->ctrl, &ctrl->admin_tag_set,
                        &nvme_fc_admin_mq_ops,
-                       struct_size((struct nvme_fcp_op_w_sgl *)NULL, priv,
-                                   ctrl->lport->ops->fcprqst_priv_sz));
+                       struct_size_t(struct nvme_fcp_op_w_sgl, priv,
+                                     ctrl->lport->ops->fcprqst_priv_sz));
        if (ret)
                goto fail_ctrl;
 

diff --git a/drivers/scsi/hptiop.c b/drivers/scsi/hptiop.c
index 06ccb51bf6a926d574f02af3c3f33490aa19bca0..f5334ccbf2cac3f1eec7cfa9b3db1ba995d4968a 100644 (file)
--- a/drivers/scsi/hptiop.c
+++ b/drivers/scsi/hptiop.c
@@ -1394,8 +1394,8 @@ static int hptiop_probe(struct pci_dev *pcidev, const struct pci_device_id *id)
        host->cmd_per_lun = le32_to_cpu(iop_config.max_requests);
        host->max_cmd_len = 16;
 
-       req_size = struct_size((struct hpt_iop_request_scsi_command *)0,
-                              sg_list, hba->max_sg_descriptors);
+       req_size = struct_size_t(struct hpt_iop_request_scsi_command,
+                                sg_list, hba->max_sg_descriptors);
        if ((req_size & 0x1f) != 0)
                req_size = (req_size + 0x1f) & ~0x1f;
 

diff --git a/drivers/scsi/megaraid/megaraid_sas_base.c b/drivers/scsi/megaraid/megaraid_sas_base.c
index 317c944c68e385168c0afd7cac69f7d8b3591a5a..050eed8e26846f4855c6fe0953240b2e3627d1d8 100644 (file)
--- a/drivers/scsi/megaraid/megaraid_sas_base.c
+++ b/drivers/scsi/megaraid/megaraid_sas_base.c
@@ -5153,8 +5153,8 @@ static void megasas_update_ext_vd_details(struct megasas_instance *instance)
                fusion->max_map_sz = ventura_map_sz;
        } else {
                fusion->old_map_sz =
-                       struct_size((struct MR_FW_RAID_MAP *)0, ldSpanMap,
-                                   instance->fw_supported_vd_count);
+                       struct_size_t(struct MR_FW_RAID_MAP, ldSpanMap,
+                                     instance->fw_supported_vd_count);
                fusion->new_map_sz =  sizeof(struct MR_FW_RAID_MAP_EXT);
 
                fusion->max_map_sz =
@@ -5789,8 +5789,8 @@ megasas_setup_jbod_map(struct megasas_instance *instance)
        struct fusion_context *fusion = instance->ctrl_context;
        size_t pd_seq_map_sz;
 
-       pd_seq_map_sz = struct_size((struct MR_PD_CFG_SEQ_NUM_SYNC *)0, seq,
-                                   MAX_PHYSICAL_DEVICES);
+       pd_seq_map_sz = struct_size_t(struct MR_PD_CFG_SEQ_NUM_SYNC, seq,
+                                     MAX_PHYSICAL_DEVICES);
 
        instance->use_seqnum_jbod_fp =
                instance->support_seqnum_jbod_fp;
@@ -8033,8 +8033,8 @@ skip_firing_dcmds:
        if (instance->adapter_type != MFI_SERIES) {
                megasas_release_fusion(instance);
                pd_seq_map_sz =
-                       struct_size((struct MR_PD_CFG_SEQ_NUM_SYNC *)0,
-                                   seq, MAX_PHYSICAL_DEVICES);
+                       struct_size_t(struct MR_PD_CFG_SEQ_NUM_SYNC,
+                                     seq, MAX_PHYSICAL_DEVICES);
                for (i = 0; i < 2 ; i++) {
                        if (fusion->ld_map[i])
                                dma_free_coherent(&instance->pdev->dev,

diff --git a/drivers/scsi/megaraid/megaraid_sas_fp.c b/drivers/scsi/megaraid/megaraid_sas_fp.c
index 4463a538102ad6d7fb1b1d266ae8a3273d38a173..b8b388a4e28ff20adc42257bd7a1cf3e9ca89b1f 100644 (file)
--- a/drivers/scsi/megaraid/megaraid_sas_fp.c
+++ b/drivers/scsi/megaraid/megaraid_sas_fp.c
@@ -326,9 +326,9 @@ u8 MR_ValidateMapInfo(struct megasas_instance *instance, u64 map_id)
        else if (instance->supportmax256vd)
                expected_size = sizeof(struct MR_FW_RAID_MAP_EXT);
        else
-               expected_size = struct_size((struct MR_FW_RAID_MAP *)0,
-                                           ldSpanMap,
-                                           le16_to_cpu(pDrvRaidMap->ldCount));
+               expected_size = struct_size_t(struct MR_FW_RAID_MAP,
+                                             ldSpanMap,
+                                             le16_to_cpu(pDrvRaidMap->ldCount));
 
        if (le32_to_cpu(pDrvRaidMap->totalSize) != expected_size) {
                dev_dbg(&instance->pdev->dev, "megasas: map info structure size 0x%x",

diff --git a/drivers/scsi/smartpqi/smartpqi_init.c b/drivers/scsi/smartpqi/smartpqi_init.c
index 03de97cd72c22c162c52c94e6490b72124feba37..f4e0aa2621642bd19eb49f0380fb4deeacb33c11 100644 (file)
--- a/drivers/scsi/smartpqi/smartpqi_init.c
+++ b/drivers/scsi/smartpqi/smartpqi_init.c
@@ -5015,7 +5015,7 @@ static int pqi_create_queues(struct pqi_ctrl_info *ctrl_info)
 }
 
 #define PQI_REPORT_EVENT_CONFIG_BUFFER_LENGTH  \
-       struct_size((struct pqi_event_config *)0, descriptors, PQI_MAX_EVENT_DESCRIPTORS)
+       struct_size_t(struct pqi_event_config,  descriptors, PQI_MAX_EVENT_DESCRIPTORS)
 
 static int pqi_configure_events(struct pqi_ctrl_info *ctrl_info,
        bool enable_events)

diff --git a/fs/xfs/libxfs/xfs_btree.h b/fs/xfs/libxfs/xfs_btree.h
index a2aa36b23e25c84da21ff4821855187c7c6051d6..4d68a58be160cf86452d4fbb21eaf1b2de8fe6a3 100644 (file)
--- a/fs/xfs/libxfs/xfs_btree.h
+++ b/fs/xfs/libxfs/xfs_btree.h
@@ -301,7 +301,7 @@ struct xfs_btree_cur
 static inline size_t
 xfs_btree_cur_sizeof(unsigned int nlevels)
 {
-       return struct_size((struct xfs_btree_cur *)NULL, bc_levels, nlevels);
+       return struct_size_t(struct xfs_btree_cur, bc_levels, nlevels);
 }
 
 /* cursor flags */

diff --git a/fs/xfs/scrub/btree.h b/fs/xfs/scrub/btree.h
index 9d7b9ee8bef47db60d5aa62a619d6458e81242de..c32b5fad6174402fd72fef14e01cc1c1a20c5f05 100644 (file)
--- a/fs/xfs/scrub/btree.h
+++ b/fs/xfs/scrub/btree.h
@@ -60,7 +60,7 @@ struct xchk_btree {
 static inline size_t
 xchk_btree_sizeof(unsigned int nlevels)
 {
-       return struct_size((struct xchk_btree *)NULL, lastkey, nlevels - 1);
+       return struct_size_t(struct xchk_btree, lastkey, nlevels - 1);
 }
 
 int xchk_btree(struct xfs_scrub *sc, struct xfs_btree_cur *cur,

diff --git a/include/linux/overflow.h b/include/linux/overflow.h
index 0e33b5cbdb9f66d558f1af65039f629fdcf417e7..f9b60313eaea2c2c2a68509f7427ff8065c6c066 100644 (file)
--- a/include/linux/overflow.h
+++ b/include/linux/overflow.h
@@ -283,7 +283,7 @@ static inline size_t __must_check size_sub(size_t minuend, size_t subtrahend)
  * @member: Name of the array member.
  * @count: Number of elements in the array.
  *
- * Calculates size of memory needed for structure @p followed by an
+ * Calculates size of memory needed for structure of @p followed by an
  * array of @count number of @member elements.
  *
  * Return: number of bytes needed or SIZE_MAX on overflow.
@@ -293,4 +293,20 @@ static inline size_t __must_check size_sub(size_t minuend, size_t subtrahend)
                sizeof(*(p)) + flex_array_size(p, member, count),       \
                size_add(sizeof(*(p)), flex_array_size(p, member, count)))
 
+/**
+ * struct_size_t() - Calculate size of structure with trailing flexible array
+ * @type: structure type name.
+ * @member: Name of the array member.
+ * @count: Number of elements in the array.
+ *
+ * Calculates size of memory needed for structure @type followed by an
+ * array of @count number of @member elements. Prefer using struct_size()
+ * when possible instead, to keep calculations associated with a specific
+ * instance variable of type @type.
+ *
+ * Return: number of bytes needed or SIZE_MAX on overflow.
+ */
+#define struct_size_t(type, member, count)                                     \
+       struct_size((type *)NULL, member, count)
+
 #endif /* __LINUX_OVERFLOW_H */

diff --git a/lib/overflow_kunit.c b/lib/overflow_kunit.c
index dcd3ba102db6985bd49942a700a54f3682fa8d5b..34db0b3aa502346bcc3bb339c19c06bf128e035c 100644 (file)
--- a/lib/overflow_kunit.c
+++ b/lib/overflow_kunit.c
@@ -649,7 +649,7 @@ struct __test_flex_array {
 static void overflow_size_helpers_test(struct kunit *test)
 {
        /* Make sure struct_size() can be used in a constant expression. */
-       u8 ce_array[struct_size((struct __test_flex_array *)0, data, 55)];
+       u8 ce_array[struct_size_t(struct __test_flex_array, data, 55)];
        struct __test_flex_array *obj;
        int count = 0;
        int var;