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/
Reviewed-by: Kees Cook <[email protected]>
Signed-off-by: Gustavo A. R. Silva <[email protected]>
---
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 44f9a05db94e..bc56e058a523 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;
}
--
2.27.0
Gustavo,
> 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.
Applied to 5.13/scsi-staging, thanks!
--
Martin K. Petersen Oracle Linux Engineering
Hi Martin,
On 3/16/21 22:32, Martin K. Petersen wrote:
>
> Gustavo,
>
>> 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.
>
> Applied to 5.13/scsi-staging, thanks!
Awesome. :)
I wonder if you can take a look at this one, too, please:
https://lore.kernel.org/lkml/20210304203822.GA102218@embeddedor/
Thanks!
--
Gustavo
On Wed, 10 Mar 2021 17:59:51 -0600, Gustavo A. R. Silva wrote:
> 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:
>
> [...]
Applied to 5.13/scsi-queue, thanks!
[1/1] scsi: mpt3sas: Replace unnecessary dynamic allocation with a static one
https://git.kernel.org/mkp/scsi/c/a1c4d7741323
--
Martin K. Petersen Oracle Linux Engineering