[PATCH 0/1] lockd: Change nsm_use_hostnames from bool to u32
From: Jia He
Date: Sun Dec 11 2016 - 09:49:39 EST
nsm_use_hostnames is a module parameter and it will be exported to sysctl
procfs. This is to let user sometimes change it from userspace. But the
minimal unit for sysctl procfs read/write it sizeof(int).
In big endian system, the converting from/to bool to/from int will cause
error for proc items.
This patch changes the type definition of nsm_use_hostnames.
The test case I used:
/***************************************************************/
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/sysctl.h>
bool __read_mostly nsm_use_hostnames;
module_param(nsm_use_hostnames, bool, 0644);
static struct ctl_table my_sysctl[] = {
{
.procname = "nsm_use_hostnames",
.data = &nsm_use_hostnames,
.maxlen = sizeof(int),
.mode = 0644,
.proc_handler = &proc_dointvec,
},
{}
};
static struct ctl_table my_root[] = {
{
.procname = "mysysctl",
.mode = 0555,
.child = my_sysctl,
},
{}
};
static struct ctl_table_header * my_ctl_header;
static int __init sysctl_exam_init(void)
{
my_ctl_header = register_sysctl_table(&my_root);
if (my_ctl_header == NULL)
printk("error regiester sysctl");
return 0;
}
static void __exit sysctl_exam_exit(void)
{
unregister_sysctl_table(my_ctl_header);
}
module_init(sysctl_exam_init);
module_exit(sysctl_exam_exit);
MODULE_LICENSE("GPL");
/****************************************************************/
[root@bigendian my]# insmod -f /root/my/hello.ko nsm_use_hostnames=1
[root@bigendian my]# cat /proc/sys/mysysctl/nsm_use_hostnames
16777216
After I change the bool to int:
[root@bigendian my]# insmod -f /root/my/hello.ko nsm_use_hostnames=1
[root@bigendian my]# cat /proc/sys/mysysctl/nsm_use_hostnames
1
In little endian system, there is no such issue.
Jia He (1):
lockd: Change nsm_use_hostnames from bool to u32
fs/lockd/mon.c | 2 +-
fs/lockd/svc.c | 2 +-
2 files changed, 2 insertions(+), 2 deletions(-)
--
2.5.5