[PATCH 1/9] x86/intel_rdt: Fix MBA parsing callback

From: Fenghua Yu
Date: Fri Sep 14 2018 - 16:36:09 EST


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.

Commit 9ab9aa15c309 ("x86/intel_rdt: Ensure requested schemata
respects mode") changes the first parameter 'data' of parse_ctrlval()
from string to a pointer to a structure. parse_ctrlval() could point
to two functions parse_cbm() and parse_bw() and both of the
functions should be changed to take the different type of parameter
'data'. But the commit only changes parse_cbm(), not parse_bw().
Thus, parse_bw() takes wrong 'data' parameter and causes failure
of parsing MBA throttle value.

To fix the issue, parse_bw() should handle its first parameter as
right structure instead of a string.

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 | 2 +-
arch/x86/kernel/cpu/intel_rdt_ctrlmondata.c | 24 ++++++++++-----------
2 files changed, 13 insertions(+), 13 deletions(-)

diff --git a/arch/x86/kernel/cpu/intel_rdt.h b/arch/x86/kernel/cpu/intel_rdt.h
index 4e588f36228f..8c30772e37ed 100644
--- a/arch/x86/kernel/cpu/intel_rdt.h
+++ b/arch/x86/kernel/cpu/intel_rdt.h
@@ -432,7 +432,7 @@ struct rdt_resource {
};

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_bw(void *_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..d427c86e7cd0 100644
--- a/arch/x86/kernel/cpu/intel_rdt_ctrlmondata.c
+++ b/arch/x86/kernel/cpu/intel_rdt_ctrlmondata.c
@@ -28,6 +28,11 @@
#include <linux/slab.h>
#include "intel_rdt.h"

+struct rdt_parse_data {
+ struct rdtgroup *rdtgrp;
+ char *buf;
+};
+
/*
* Check whether MBA bandwidth percentage value is correct. The value is
* checked against the minimum and max bandwidth values specified by the
@@ -64,19 +69,19 @@ 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(void *_data, struct rdt_resource *r, struct rdt_domain *d)
{
- unsigned long data;
- char *buf = _buf;
+ struct rdt_parse_data *data = _data;
+ 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 +128,13 @@ 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)
{
- struct rdt_cbm_parse_data *data = _data;
+ struct rdt_parse_data *data = _data;
struct rdtgroup *rdtgrp = data->rdtgrp;
u32 cbm_val;

@@ -195,7 +195,7 @@ 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