From a1c4d7741323eff1d9c5baca8337ac3ac4630649 Mon Sep 17 00:00:00 2001 From: "Gustavo A. R. Silva" Date: Wed, 10 Mar 2021 17:59:51 -0600 Subject: [PATCH] scsi: mpt3sas: Replace unnecessary dynamic allocation with a static one MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit Dynamic memory allocation isn't actually needed and it can be replaced by statically allocating memory for struct object io_unit_pg3 with 36 hardcoded entries for its GPIOVal array. Also, this helps the with ongoing efforts to enable -Warray-bounds by fixing the following warning: drivers/scsi/mpt3sas/mpt3sas_ctl.c: In function ‘BRM_status_show’: drivers/scsi/mpt3sas/mpt3sas_ctl.c:3257:63: warning: array subscript 24 is above array bounds of ‘U16[1]’ {aka ‘short unsigned int[1]’} [-Warray-bounds] 3257 | backup_rail_monitor_status = le16_to_cpu(io_unit_pg3->GPIOVal[24]); ./include/uapi/linux/byteorder/little_endian.h:36:51: note: in definition of macro ‘__le16_to_cpu’ 36 | #define __le16_to_cpu(x) ((__force __u16)(__le16)(x)) | ^ drivers/scsi/mpt3sas/mpt3sas_ctl.c:3257:31: note: in expansion of macro ‘le16_to_cpu’ 3257 | backup_rail_monitor_status = le16_to_cpu(io_unit_pg3->GPIOVal[24]); Link: https://github.com/KSPP/linux/issues/109 Link: https://lore.kernel.org/lkml/202103101058.16ED27BE3@keescook/ Link: https://lore.kernel.org/r/20210310235951.GA108661@embeddedor Reviewed-by: Kees Cook Signed-off-by: Gustavo A. R. Silva Signed-off-by: Martin K. Petersen --- drivers/scsi/mpt3sas/mpi/mpi2_cnfg.h | 2 +- drivers/scsi/mpt3sas/mpt3sas_ctl.c | 24 ++++++++---------------- 2 files changed, 9 insertions(+), 17 deletions(-) diff --git a/drivers/scsi/mpt3sas/mpi/mpi2_cnfg.h b/drivers/scsi/mpt3sas/mpi/mpi2_cnfg.h index 43a3bf8ff428..d00431f553e1 100644 --- a/drivers/scsi/mpt3sas/mpi/mpi2_cnfg.h +++ b/drivers/scsi/mpt3sas/mpi/mpi2_cnfg.h @@ -992,7 +992,7 @@ typedef struct _MPI2_CONFIG_PAGE_IO_UNIT_1 { *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) +#define MPI2_IO_UNIT_PAGE_3_GPIO_VAL_MAX (36) #endif typedef struct _MPI2_CONFIG_PAGE_IO_UNIT_3 { diff --git a/drivers/scsi/mpt3sas/mpt3sas_ctl.c b/drivers/scsi/mpt3sas/mpt3sas_ctl.c index 8717412b8079..e7582fb8a93f 100644 --- a/drivers/scsi/mpt3sas/mpt3sas_ctl.c +++ b/drivers/scsi/mpt3sas/mpt3sas_ctl.c @@ -3203,7 +3203,7 @@ BRM_status_show(struct device *cdev, struct device_attribute *attr, { struct Scsi_Host *shost = class_to_shost(cdev); struct MPT3SAS_ADAPTER *ioc = shost_priv(shost); - Mpi2IOUnitPage3_t *io_unit_pg3 = NULL; + Mpi2IOUnitPage3_t io_unit_pg3; Mpi2ConfigReply_t mpi_reply; u16 backup_rail_monitor_status = 0; u16 ioc_status; @@ -3220,17 +3220,10 @@ BRM_status_show(struct device *cdev, struct device_attribute *attr, if (ioc->pci_error_recovery || ioc->remove_host) goto out; - /* allocate upto GPIOVal 36 entries */ - sz = offsetof(Mpi2IOUnitPage3_t, GPIOVal) + (sizeof(u16) * 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", - __func__, sz); - goto out; - } + sz = sizeof(io_unit_pg3); + memset(&io_unit_pg3, 0, sz); - if (mpt3sas_config_get_iounit_pg3(ioc, &mpi_reply, io_unit_pg3, sz) != + if (mpt3sas_config_get_iounit_pg3(ioc, &mpi_reply, &io_unit_pg3, sz) != 0) { ioc_err(ioc, "%s: failed reading iounit_pg3\n", __func__); @@ -3246,19 +3239,18 @@ BRM_status_show(struct device *cdev, struct device_attribute *attr, goto out; } - if (io_unit_pg3->GPIOCount < 25) { - ioc_err(ioc, "%s: iounit_pg3->GPIOCount less than 25 entries, detected (%d) entries\n", - __func__, io_unit_pg3->GPIOCount); + if (io_unit_pg3.GPIOCount < 25) { + ioc_err(ioc, "%s: iounit_pg3.GPIOCount less than 25 entries, detected (%d) entries\n", + __func__, io_unit_pg3.GPIOCount); rc = -EINVAL; goto out; } /* BRM status is in bit zero of GPIOVal[24] */ - backup_rail_monitor_status = le16_to_cpu(io_unit_pg3->GPIOVal[24]); + backup_rail_monitor_status = le16_to_cpu(io_unit_pg3.GPIOVal[24]); rc = snprintf(buf, PAGE_SIZE, "%d\n", (backup_rail_monitor_status & 1)); out: - kfree(io_unit_pg3); mutex_unlock(&ioc->pci_access_mutex); return rc; } -- 2.20.1