[PATCH V2 1/9] x86/intel_rdt: Fix data type in parsing callbacks

[Fenghua Yu]

From: Xiaochen Shen <xiaochen.shen@xxxxxxxxx>

Each resource is associated with a parsing callback to parse the data
provided from user space when writing schemata file.

The 'data' parameter in the callbacks is defined as a void pointer which
is error prone due to lack of type check.

parse_bw() processes the 'data' parameter as a string while its caller
actually passes the parameter as a pointer to struct rdt_cbm_parse_data.
Thus, parse_bw() takes wrong data and causes failure of parsing MBA
throttle value.

To fix the issue, the 'data' parameter in the parsing callbacks is
defined and handled as a pointer to struct rdt_parse_data (renamed from
struct rdt_cbm_parse_data).

Fixes: 7604df6e16ae ("x86/intel_rdt: Support flexible data to parsing callbacks")
Fixes: 9ab9aa15c309 ("x86/intel_rdt: Ensure requested schemata respects mode")

Signed-off-by: Xiaochen Shen <xiaochen.shen@xxxxxxxxx>
Signed-off-by: Reinette Chatre <reinette.chatre@xxxxxxxxx>
Signed-off-by: Fenghua Yu <fenghua.yu@xxxxxxxxx>
---
 arch/x86/kernel/cpu/intel_rdt.h             | 16 ++++++++++++----
 arch/x86/kernel/cpu/intel_rdt_ctrlmondata.c | 21 ++++++++-------------
 2 files changed, 20 insertions(+), 17 deletions(-)

diff --git a/arch/x86/kernel/cpu/intel_rdt.h b/arch/x86/kernel/cpu/intel_rdt.h
index 4e588f36228f..78266c798280 100644
--- a/arch/x86/kernel/cpu/intel_rdt.h
+++ b/arch/x86/kernel/cpu/intel_rdt.h
@@ -382,6 +382,11 @@ static inline bool is_mbm_event(int e)
 		e <= QOS_L3_MBM_LOCAL_EVENT_ID);
 }
 
+struct rdt_parse_data {
+	struct rdtgroup		*rdtgrp;
+	char			*buf;
+};
+
 /**
  * struct rdt_resource - attributes of an RDT resource
  * @rid:		The index of the resource
@@ -423,16 +428,19 @@ struct rdt_resource {
 	struct rdt_cache	cache;
 	struct rdt_membw	membw;
 	const char		*format_str;
-	int (*parse_ctrlval)	(void *data, struct rdt_resource *r,
-				 struct rdt_domain *d);
+	int (*parse_ctrlval)(struct rdt_parse_data *data,
+			     struct rdt_resource *r,
+			     struct rdt_domain *d);
 	struct list_head	evt_list;
 	int			num_rmid;
 	unsigned int		mon_scale;
 	unsigned long		fflags;
 };
 
-int parse_cbm(void *_data, struct rdt_resource *r, struct rdt_domain *d);
-int parse_bw(void *_buf, struct rdt_resource *r,  struct rdt_domain *d);
+int parse_cbm(struct rdt_parse_data *data, struct rdt_resource *r,
+	      struct rdt_domain *d);
+int parse_bw(struct rdt_parse_data *data, struct rdt_resource *r,
+	     struct rdt_domain *d);
 
 extern struct mutex rdtgroup_mutex;
 
diff --git a/arch/x86/kernel/cpu/intel_rdt_ctrlmondata.c b/arch/x86/kernel/cpu/intel_rdt_ctrlmondata.c
index af358ca05160..edd5761f7336 100644
--- a/arch/x86/kernel/cpu/intel_rdt_ctrlmondata.c
+++ b/arch/x86/kernel/cpu/intel_rdt_ctrlmondata.c
@@ -64,19 +64,19 @@ static bool bw_validate(char *buf, unsigned long *data, struct rdt_resource *r)
 	return true;
 }
 
-int parse_bw(void *_buf, struct rdt_resource *r, struct rdt_domain *d)
+int parse_bw(struct rdt_parse_data *data, struct rdt_resource *r,
+	     struct rdt_domain *d)
 {
-	unsigned long data;
-	char *buf = _buf;
+	unsigned long bw_val;
 
 	if (d->have_new_ctrl) {
 		rdt_last_cmd_printf("duplicate domain %d\n", d->id);
 		return -EINVAL;
 	}
 
-	if (!bw_validate(buf, &data, r))
+	if (!bw_validate(data->buf, &bw_val, r))
 		return -EINVAL;
-	d->new_ctrl = data;
+	d->new_ctrl = bw_val;
 	d->have_new_ctrl = true;
 
 	return 0;
@@ -123,18 +123,13 @@ static bool cbm_validate(char *buf, u32 *data, struct rdt_resource *r)
 	return true;
 }
 
-struct rdt_cbm_parse_data {
-	struct rdtgroup		*rdtgrp;
-	char			*buf;
-};
-
 /*
  * Read one cache bit mask (hex). Check that it is valid for the current
  * resource type.
  */
-int parse_cbm(void *_data, struct rdt_resource *r, struct rdt_domain *d)
+int parse_cbm(struct rdt_parse_data *data, struct rdt_resource *r,
+	      struct rdt_domain *d)
 {
-	struct rdt_cbm_parse_data *data = _data;
 	struct rdtgroup *rdtgrp = data->rdtgrp;
 	u32 cbm_val;
 
@@ -195,7 +190,7 @@ int parse_cbm(void *_data, struct rdt_resource *r, struct rdt_domain *d)
 static int parse_line(char *line, struct rdt_resource *r,
 		      struct rdtgroup *rdtgrp)
 {
-	struct rdt_cbm_parse_data data;
+	struct rdt_parse_data data;
 	char *dom = NULL, *id;
 	struct rdt_domain *d;
 	unsigned long dom_id;
-- 
2.19.0