[PATCH] crypto: qat - use strscpy_pad to simplify adf_service_string_to_mask

[Thorsten Blum <thorsten.blum@linux.dev>]

Use strscpy_pad() to copy buf and zero-pad any trailing bytes instead of
zero-initializing the local services buffer and then using strscpy() to
copy into it. Also use the strscpy_pad() return value to detect string
truncation instead of checking the caller-provided length.

Remove the now-unused length parameters from
adf_service_string_to_mask() and adf_parse_service_string(). Also remove
the redundant strnlen() call in adf_get_service_mask(), which only
computed the removed length argument.

Signed-off-by: Thorsten Blum <thorsten.blum@linux.dev>
---
 .../intel/qat/qat_common/adf_cfg_services.c       | 15 ++++++---------
 .../intel/qat/qat_common/adf_cfg_services.h       |  2 +-
 drivers/crypto/intel/qat/qat_common/adf_sysfs.c   |  2 +-
 3 files changed, 8 insertions(+), 11 deletions(-)

diff --git a/drivers/crypto/intel/qat/qat_common/adf_cfg_services.c b/drivers/crypto/intel/qat/qat_common/adf_cfg_services.c
index 7d00bcb41ce7..21b21ac78e53 100644
--- a/drivers/crypto/intel/qat/qat_common/adf_cfg_services.c
+++ b/drivers/crypto/intel/qat/qat_common/adf_cfg_services.c
@@ -49,18 +49,17 @@ static_assert(sizeof(ADF_CFG_SYM ADF_SERVICES_DELIMITER
 		     ADF_CFG_DCC) < ADF_CFG_MAX_VAL_LEN_IN_BYTES);
 
 static int adf_service_string_to_mask(struct adf_accel_dev *accel_dev, const char *buf,
-				      size_t len, unsigned long *out_mask)
+				      unsigned long *out_mask)
 {
 	struct adf_hw_device_data *hw_data = GET_HW_DATA(accel_dev);
-	char services[ADF_CFG_MAX_VAL_LEN_IN_BYTES] = { };
+	char services[ADF_CFG_MAX_VAL_LEN_IN_BYTES];
 	unsigned long mask = 0;
 	char *substr, *token;
 	int id, num_svc = 0;
 
-	if (len > ADF_CFG_MAX_VAL_LEN_IN_BYTES - 1)
+	if (strscpy_pad(services, buf) < 0)
 		return -EINVAL;
 
-	strscpy(services, buf);
 	substr = services;
 
 	while ((token = strsep(&substr, ADF_SERVICES_DELIMITER))) {
@@ -104,12 +103,12 @@ static int adf_service_mask_to_string(unsigned long mask, char *buf, size_t len)
 }
 
 int adf_parse_service_string(struct adf_accel_dev *accel_dev, const char *in,
-			     size_t in_len, char *out, size_t out_len)
+			     char *out, size_t out_len)
 {
 	unsigned long mask;
 	int ret;
 
-	ret = adf_service_string_to_mask(accel_dev, in, in_len, &mask);
+	ret = adf_service_string_to_mask(accel_dev, in, &mask);
 	if (ret)
 		return ret;
 
@@ -122,7 +121,6 @@ int adf_parse_service_string(struct adf_accel_dev *accel_dev, const char *in,
 int adf_get_service_mask(struct adf_accel_dev *accel_dev, unsigned long *mask)
 {
 	char services[ADF_CFG_MAX_VAL_LEN_IN_BYTES] = { };
-	size_t len;
 	int ret;
 
 	ret = adf_cfg_get_param_value(accel_dev, ADF_GENERAL_SEC,
@@ -133,8 +131,7 @@ int adf_get_service_mask(struct adf_accel_dev *accel_dev, unsigned long *mask)
 		return ret;
 	}
 
-	len = strnlen(services, ADF_CFG_MAX_VAL_LEN_IN_BYTES);
-	ret = adf_service_string_to_mask(accel_dev, services, len, mask);
+	ret = adf_service_string_to_mask(accel_dev, services, mask);
 	if (ret)
 		dev_err(&GET_DEV(accel_dev), "Invalid value of %s param: %s\n",
 			ADF_SERVICES_ENABLED, services);
diff --git a/drivers/crypto/intel/qat/qat_common/adf_cfg_services.h b/drivers/crypto/intel/qat/qat_common/adf_cfg_services.h
index 913d717280af..89be2f2c7233 100644
--- a/drivers/crypto/intel/qat/qat_common/adf_cfg_services.h
+++ b/drivers/crypto/intel/qat/qat_common/adf_cfg_services.h
@@ -35,7 +35,7 @@ enum {
 #define MAX_NUM_CONCURR_SVC	ADF_THREE_SERVICES
 
 int adf_parse_service_string(struct adf_accel_dev *accel_dev, const char *in,
-			     size_t in_len, char *out, size_t out_len);
+			     char *out, size_t out_len);
 int adf_get_service_enabled(struct adf_accel_dev *accel_dev);
 int adf_get_service_mask(struct adf_accel_dev *accel_dev, unsigned long *mask);
 enum adf_cfg_service_type adf_srv_to_cfg_svc_type(enum adf_base_services svc);
diff --git a/drivers/crypto/intel/qat/qat_common/adf_sysfs.c b/drivers/crypto/intel/qat/qat_common/adf_sysfs.c
index 79c63dfa8ff3..8daa69a76b01 100644
--- a/drivers/crypto/intel/qat/qat_common/adf_sysfs.c
+++ b/drivers/crypto/intel/qat/qat_common/adf_sysfs.c
@@ -125,7 +125,7 @@ static ssize_t cfg_services_store(struct device *dev, struct device_attribute *a
 	if (!accel_dev)
 		return -EINVAL;
 
-	ret = adf_parse_service_string(accel_dev, buf, count, services,
+	ret = adf_parse_service_string(accel_dev, buf, services,
 				       ADF_CFG_MAX_VAL_LEN_IN_BYTES);
 	if (ret)
 		return ret;