RDMA: Manual changes for sysfs_emit and neatening

Make changes to use sysfs_emit in the RDMA code as cocci scripts can not
be written to handle _all_ the possible variants of various sprintf family
uses in sysfs show functions.

While there, make the code more legible and update its style to be more
like the typical kernel styles.

Miscellanea:

o Use intermediate pointers for dereferences
o Add and use string lookup functions
o return early when any intermediate call fails so normal return is
  at the bottom of the function
o mlx4/mcg.c:sysfs_show_group: use scnprintf to format intermediate strings

Link: https://lore.kernel.org/r/f5c9e4c9d8dafca1b7b70bd597ee7f8f219c31c8.1602122880.git.joe@perches.com
Signed-off-by: Joe Perches <joe@perches.com>
Acked-by: Jack Wang <jinpu.wang@cloud.ionos.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>

1 files changed, 22 insertions, 26 deletions

diff --git a/drivers/infiniband/hw/qib/qib_sysfs.c b/drivers/infiniband/hw/qib/qib_sysfs.c
index 818282bc7c5b..3761f21cef97 100644
--- a/drivers/infiniband/hw/qib/qib_sysfs.c
+++ b/drivers/infiniband/hw/qib/qib_sysfs.c
@@ -575,13 +575,10 @@ static ssize_t hca_type_show(struct device *device,
 	struct qib_ibdev *dev =
 		rdma_device_to_drv_device(device, struct qib_ibdev, rdi.ibdev);
 	struct qib_devdata *dd = dd_from_dev(dev);
-	int ret;
 
 	if (!dd->boardname)
-		ret = -EINVAL;
-	else
-		ret = sysfs_emit(buf, "%s\n", dd->boardname);
-	return ret;
+		return -EINVAL;
+	return sysfs_emit(buf, "%s\n", dd->boardname);
 }
 static DEVICE_ATTR_RO(hca_type);
 static DEVICE_ATTR(board_id, 0444, hca_type_show, NULL);
@@ -647,17 +644,16 @@ static ssize_t nfreectxts_show(struct device *device,
 }
 static DEVICE_ATTR_RO(nfreectxts);
 
-static ssize_t serial_show(struct device *device,
-			   struct device_attribute *attr, char *buf)
+static ssize_t serial_show(struct device *device, struct device_attribute *attr,
+			   char *buf)
 {
 	struct qib_ibdev *dev =
 		rdma_device_to_drv_device(device, struct qib_ibdev, rdi.ibdev);
 	struct qib_devdata *dd = dd_from_dev(dev);
+	const u8 *end = memchr(dd->serial, 0, ARRAY_SIZE(dd->serial));
+	int size = end ? end - dd->serial : ARRAY_SIZE(dd->serial);
 
-	buf[sizeof(dd->serial)] = '\0';
-	memcpy(buf, dd->serial, sizeof(dd->serial));
-	strcat(buf, "\n");
-	return strlen(buf);
+	return sysfs_emit(buf, ".%*s\n", size, dd->serial);
 }
 static DEVICE_ATTR_RO(serial);
 
@@ -690,26 +686,26 @@ static ssize_t tempsense_show(struct device *device,
 	struct qib_ibdev *dev =
 		rdma_device_to_drv_device(device, struct qib_ibdev, rdi.ibdev);
 	struct qib_devdata *dd = dd_from_dev(dev);
-	int ret;
-	int idx;
+	int i;
 	u8 regvals[8];
 
-	ret = -ENXIO;
-	for (idx = 0; idx < 8; ++idx) {
-		if (idx == 6)
+	for (i = 0; i < 8; i++) {
+		int ret;
+
+		if (i == 6)
 			continue;
-		ret = dd->f_tempsense_rd(dd, idx);
+		ret = dd->f_tempsense_rd(dd, i);
 		if (ret < 0)
-			break;
-		regvals[idx] = ret;
+			return ret;	/* return error on bad read */
+		regvals[i] = ret;
 	}
-	if (idx == 8)
-		ret = sysfs_emit(buf, "%d %d %02X %02X %d %d\n",
-				 *(signed char *)(regvals),
-				 *(signed char *)(regvals + 1), regvals[2],
-				 regvals[3], *(signed char *)(regvals + 5),
-				 *(signed char *)(regvals + 7));
-	return ret;
+	return sysfs_emit(buf, "%d %d %02X %02X %d %d\n",
+			  (signed char)regvals[0],
+			  (signed char)regvals[1],
+			  regvals[2],
+			  regvals[3],
+			  (signed char)regvals[5],
+			  (signed char)regvals[7]);
 }
 static DEVICE_ATTR_RO(tempsense);