There is a regular need in the kernel to provide a way to declare having a dynamically sized set of trailing elements in a structure. Kernel code should always use “flexible array members”[1] for these cases. The older style of one-element or zero-length arrays should no longer be used[2]. Refactor the code according to the use of a flexible-array member in struct _MPI2_CONFIG_PAGE_IO_UNIT_3, instead of a one-element array, and use the struct_size() helper to calculate the size for the allocation. Also, this helps the ongoing efforts to enable -Warray-bounds and fix the following warnings: drivers/scsi/mpt3sas/mpt3sas_ctl.c:3193:63: warning: array subscript 24 is above array bounds of ‘U16[1]’ {aka ‘short unsigned int[1]’} [-Warray-bounds] [1] https://en.wikipedia.org/wiki/Flexible_array_member [2] https://www.kernel.org/doc/html/v5.9/process/deprecated.html#zero-length-and-one-element-arrays Link: https://github.com/KSPP/linux/issues/79 Link: https://github.com/KSPP/linux/issues/109 Signed-off-by: Gustavo A. R. Silva <gustavoars@xxxxxxxxxx> --- Changes in v2: - Fix format specifier: use %zu for size_t type. drivers/scsi/mpt3sas/mpi/mpi2_cnfg.h | 11 +---------- drivers/scsi/mpt3sas/mpt3sas_ctl.c | 6 +++--- 2 files changed, 4 insertions(+), 13 deletions(-) diff --git a/drivers/scsi/mpt3sas/mpi/mpi2_cnfg.h b/drivers/scsi/mpt3sas/mpi/mpi2_cnfg.h index 43a3bf8ff428..908b0ca63204 100644 --- a/drivers/scsi/mpt3sas/mpi/mpi2_cnfg.h +++ b/drivers/scsi/mpt3sas/mpi/mpi2_cnfg.h @@ -987,21 +987,12 @@ typedef struct _MPI2_CONFIG_PAGE_IO_UNIT_1 { /*IO Unit Page 3 */ -/* - *Host code (drivers, BIOS, utilities, etc.) should leave this define set to - *one and check the value returned for GPIOCount at runtime. - */ -#ifndef MPI2_IO_UNIT_PAGE_3_GPIO_VAL_MAX -#define MPI2_IO_UNIT_PAGE_3_GPIO_VAL_MAX (1) -#endif - typedef struct _MPI2_CONFIG_PAGE_IO_UNIT_3 { MPI2_CONFIG_PAGE_HEADER Header; /*0x00 */ U8 GPIOCount; /*0x04 */ U8 Reserved1; /*0x05 */ U16 Reserved2; /*0x06 */ - U16 - GPIOVal[MPI2_IO_UNIT_PAGE_3_GPIO_VAL_MAX];/*0x08 */ + U16 GPIOVal[]; /*0x08 */ } MPI2_CONFIG_PAGE_IO_UNIT_3, *PTR_MPI2_CONFIG_PAGE_IO_UNIT_3, Mpi2IOUnitPage3_t, *pMpi2IOUnitPage3_t; diff --git a/drivers/scsi/mpt3sas/mpt3sas_ctl.c b/drivers/scsi/mpt3sas/mpt3sas_ctl.c index c8a0ce18f2c5..ffb21f873058 100644 --- a/drivers/scsi/mpt3sas/mpt3sas_ctl.c +++ b/drivers/scsi/mpt3sas/mpt3sas_ctl.c @@ -3143,7 +3143,7 @@ BRM_status_show(struct device *cdev, struct device_attribute *attr, Mpi2ConfigReply_t mpi_reply; u16 backup_rail_monitor_status = 0; u16 ioc_status; - int sz; + size_t sz; ssize_t rc = 0; if (!ioc->is_warpdrive) { @@ -3157,11 +3157,11 @@ BRM_status_show(struct device *cdev, struct device_attribute *attr, goto out; /* allocate upto GPIOVal 36 entries */ - sz = offsetof(Mpi2IOUnitPage3_t, GPIOVal) + (sizeof(u16) * 36); + sz = struct_size(io_unit_pg3, GPIOVal, 36); io_unit_pg3 = kzalloc(sz, GFP_KERNEL); if (!io_unit_pg3) { rc = -ENOMEM; - ioc_err(ioc, "%s: failed allocating memory for iounit_pg3: (%d) bytes\n", + ioc_err(ioc, "%s: failed allocating memory for iounit_pg3: (%zu) bytes\n", __func__, sz); goto out; } -- 2.27.0