[PATCH 0/4] SCSI-HPSA: Adjustments for hpsa_big_passthru_ioctl()

[PATCH 0/4] SCSI-HPSA: Adjustments for hpsa_big_passthru_ioctl()

[SF Markus Elfring]

From: Markus Elfring <elfring@users.sourceforge.net>
Date: Mon, 5 Mar 2018 09:14:32 +0100

A few update suggestions were taken into account
from static source code analysis.

Markus Elfring (4):
  Use memdup_user() rather than duplicating its implementation
  Less function calls in hpsa_big_passthru_ioctl() after error detection
  Delete an unnecessary initialisation
  Move a variable assignment

 drivers/scsi/hpsa.c | 44 +++++++++++++++++++++-----------------------
 1 file changed, 21 insertions(+), 23 deletions(-)

-- 
2.16.2

[PATCH 1/4] scsi: hpsa: Use memdup_user() rather than duplicating its implementation

[SF Markus Elfring]

From: Markus Elfring <elfring@users.sourceforge.net>
Date: Sun, 4 Mar 2018 21:19:52 +0100

* Reuse existing functionality from memdup_user() instead of keeping
  duplicate source code.

  This issue was detected by using the Coccinelle software.

* Return directly after this function call failed at the beginning.

Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>
---
 drivers/scsi/hpsa.c | 13 ++++---------
 1 file changed, 4 insertions(+), 9 deletions(-)

diff --git a/drivers/scsi/hpsa.c b/drivers/scsi/hpsa.c
index 5293e6827ce5..b35248becef9 100644
--- a/drivers/scsi/hpsa.c
+++ b/drivers/scsi/hpsa.c
@@ -6390,15 +6390,10 @@ static int hpsa_big_passthru_ioctl(struct ctlr_info *h, void __user *argp)
 		return -EINVAL;
 	if (!capable(CAP_SYS_RAWIO))
 		return -EPERM;
-	ioc = kmalloc(sizeof(*ioc), GFP_KERNEL);
-	if (!ioc) {
-		status = -ENOMEM;
-		goto cleanup1;
-	}
-	if (copy_from_user(ioc, argp, sizeof(*ioc))) {
-		status = -EFAULT;
-		goto cleanup1;
-	}
+	ioc = memdup_user(argp, sizeof(*ioc));
+	if (IS_ERR(ioc))
+		return PTR_ERR(ioc);
+
 	if ((ioc->buf_size < 1) &&
 	    (ioc->Request.Type.Direction != XFER_NONE)) {
 		status = -EINVAL;
-- 
2.16.2

[PATCH 2/4] scsi: hpsa: Less function calls in hpsa_big_passthru_ioctl() after error detection

[SF Markus Elfring]

From: Markus Elfring <elfring@users.sourceforge.net>
Date: Sun, 4 Mar 2018 22:00:19 +0100

The function "kfree" was called in a few cases by
the hpsa_big_passthru_ioctl() function during error handling
even if the passed variable contained a null pointer.

* Adjust jump targets.

* Delete two initialisations and a check (for the local variable "buff")
  which became unnecessary with this refactoring.

Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>
---
 drivers/scsi/hpsa.c | 26 ++++++++++++++------------
 1 file changed, 14 insertions(+), 12 deletions(-)

diff --git a/drivers/scsi/hpsa.c b/drivers/scsi/hpsa.c
index b35248becef9..45177ead811f 100644
--- a/drivers/scsi/hpsa.c
+++ b/drivers/scsi/hpsa.c
@@ -6377,8 +6377,8 @@ static int hpsa_big_passthru_ioctl(struct ctlr_info *h, void __user *argp)
 {
 	BIG_IOCTL_Command_struct *ioc;
 	struct CommandList *c;
-	unsigned char **buff = NULL;
-	int *buff_size = NULL;
+	unsigned char **buff;
+	int *buff_size;
 	u64 temp64;
 	BYTE sg_used = 0;
 	int status = 0;
@@ -6397,26 +6397,26 @@ static int hpsa_big_passthru_ioctl(struct ctlr_info *h, void __user *argp)
 	if ((ioc->buf_size < 1) &&
 	    (ioc->Request.Type.Direction != XFER_NONE)) {
 		status = -EINVAL;
-		goto cleanup1;
+		goto free_ioc;
 	}
 	/* Check kmalloc limits  using all SGs */
 	if (ioc->malloc_size > MAX_KMALLOC_SIZE) {
 		status = -EINVAL;
-		goto cleanup1;
+		goto free_ioc;
 	}
 	if (ioc->buf_size > ioc->malloc_size * SG_ENTRIES_IN_CMD) {
 		status = -EINVAL;
-		goto cleanup1;
-	}
-	buff = kzalloc(SG_ENTRIES_IN_CMD * sizeof(char *), GFP_KERNEL);
-	if (!buff) {
-		status = -ENOMEM;
-		goto cleanup1;
+		goto free_ioc;
 	}
 	buff_size = kmalloc(SG_ENTRIES_IN_CMD * sizeof(int), GFP_KERNEL);
 	if (!buff_size) {
 		status = -ENOMEM;
-		goto cleanup1;
+		goto free_ioc;
+	}
+	buff = kzalloc(SG_ENTRIES_IN_CMD * sizeof(char *), GFP_KERNEL);
+	if (!buff) {
+		status = -ENOMEM;
+		goto free_buff_size;
 	}
 	left = ioc->buf_size;
 	data_ptr = ioc->buf;
@@ -6501,14 +6501,16 @@ static int hpsa_big_passthru_ioctl(struct ctlr_info *h, void __user *argp)
 cleanup0:
 	cmd_free(h, c);
 cleanup1:
-	if (buff) {
+	{
 		int i;
 
 		for (i = 0; i < sg_used; i++)
 			kfree(buff[i]);
 		kfree(buff);
 	}
+free_buff_size:
 	kfree(buff_size);
+free_ioc:
 	kfree(ioc);
 	return status;
 }
-- 
2.16.2

[PATCH 3/4] scsi: hpsa: Delete an unnecessary initialisation in hpsa_big_passthru_ioctl()

[SF Markus Elfring]

From: Markus Elfring <elfring@users.sourceforge.net>
Date: Sun, 4 Mar 2018 22:02:10 +0100

The variable "status" will be set to an appropriate value a bit later.
Thus omit the explicit initialisation at the beginning.

Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>
---
 drivers/scsi/hpsa.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/scsi/hpsa.c b/drivers/scsi/hpsa.c
index 45177ead811f..86d371ab39e7 100644
--- a/drivers/scsi/hpsa.c
+++ b/drivers/scsi/hpsa.c
@@ -6381,7 +6381,7 @@ static int hpsa_big_passthru_ioctl(struct ctlr_info *h, void __user *argp)
 	int *buff_size;
 	u64 temp64;
 	BYTE sg_used = 0;
-	int status = 0;
+	int status;
 	u32 left;
 	u32 sz;
 	BYTE __user *data_ptr;
-- 
2.16.2

[PATCH 4/4] scsi: hpsa: Move a variable assignment in hpsa_big_passthru_ioctl()

[SF Markus Elfring]

From: Markus Elfring <elfring@users.sourceforge.net>
Date: Sun, 4 Mar 2018 22:16:05 +0100

Move an assignment for the local variable "sg_used" so that its setting
will only be performed after corresponding memory allocations succeeded
by this function.

Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>
---
 drivers/scsi/hpsa.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/scsi/hpsa.c b/drivers/scsi/hpsa.c
index 86d371ab39e7..bb6df194ac31 100644
--- a/drivers/scsi/hpsa.c
+++ b/drivers/scsi/hpsa.c
@@ -6380,7 +6380,7 @@ static int hpsa_big_passthru_ioctl(struct ctlr_info *h, void __user *argp)
 	unsigned char **buff;
 	int *buff_size;
 	u64 temp64;
-	BYTE sg_used = 0;
+	BYTE sg_used;
 	int status;
 	u32 left;
 	u32 sz;
@@ -6420,6 +6420,7 @@ static int hpsa_big_passthru_ioctl(struct ctlr_info *h, void __user *argp)
 	}
 	left = ioc->buf_size;
 	data_ptr = ioc->buf;
+	sg_used = 0;
 	while (left) {
 		sz = (left > ioc->malloc_size) ? ioc->malloc_size : left;
 		buff_size[sg_used] = sz;
-- 
2.16.2

Re: [2/4] scsi: hpsa: Less function calls in hpsa_big_passthru_ioctl() after error detection

[SF Markus Elfring]

>> @@ -6501,14 +6501,16 @@ static int hpsa_big_passthru_ioctl(struct ctlr_info
>> *h, void __user *argp)
>>  cleanup0:
>>         cmd_free(h, c);
>>  cleanup1:
>> -       if (buff) {
>> +       {
>>                 int i;
>>
>>                 for (i = 0; i < sg_used; i++)
>>                         kfree(buff[i]);
>>                 kfree(buff);
>>         }
> 
> Thanks for looking at the hpsa driver.
> 
> This HUNK ends up with an unnamed block.

Which identifier would you like to use there?


> I would prefer to not have it structured like this.

Would you like to show a source code layout alternative?

Regards,
Markus