Commit f5dd3d6f authored by Sam Vilain's avatar Sam Vilain Committed by Linus Torvalds

[PATCH] proc: sysctl: add _proc_do_string helper

The logic in proc_do_string is worth re-using without passing in a
ctl_table structure (say, we want to calculate a pointer and pass that in
instead); pass in the two fields it uses from that structure as explicit
arguments.
Signed-off-by: default avatarSam Vilain <sam.vilain@catalyst.net.nz>
Cc: Serge E. Hallyn <serue@us.ibm.com>
Cc: Kirill Korotaev <dev@openvz.org>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Herbert Poetzl <herbert@13thfloor.at>
Cc: Andrey Savochkin <saw@sw.ru>
Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
parent 12fd3520
......@@ -1624,32 +1624,14 @@ static ssize_t proc_writesys(struct file * file, const char __user * buf,
return do_rw_proc(1, file, (char __user *) buf, count, ppos);
}
/**
* proc_dostring - read a string sysctl
* @table: the sysctl table
* @write: %TRUE if this is a write to the sysctl file
* @filp: the file structure
* @buffer: the user buffer
* @lenp: the size of the user buffer
* @ppos: file position
*
* Reads/writes a string from/to the user buffer. If the kernel
* buffer provided is not large enough to hold the string, the
* string is truncated. The copied string is %NULL-terminated.
* If the string is being read by the user process, it is copied
* and a newline '\n' is added. It is truncated if the buffer is
* not large enough.
*
* Returns 0 on success.
*/
int proc_dostring(ctl_table *table, int write, struct file *filp,
void __user *buffer, size_t *lenp, loff_t *ppos)
int _proc_do_string(void* data, int maxlen, int write, struct file *filp,
void __user *buffer, size_t *lenp, loff_t *ppos)
{
size_t len;
char __user *p;
char c;
if (!table->data || !table->maxlen || !*lenp ||
if (!data || !maxlen || !*lenp ||
(*ppos && !write)) {
*lenp = 0;
return 0;
......@@ -1665,20 +1647,20 @@ int proc_dostring(ctl_table *table, int write, struct file *filp,
break;
len++;
}
if (len >= table->maxlen)
len = table->maxlen-1;
if(copy_from_user(table->data, buffer, len))
if (len >= maxlen)
len = maxlen-1;
if(copy_from_user(data, buffer, len))
return -EFAULT;
((char *) table->data)[len] = 0;
((char *) data)[len] = 0;
*ppos += *lenp;
} else {
len = strlen(table->data);
if (len > table->maxlen)
len = table->maxlen;
len = strlen(data);
if (len > maxlen)
len = maxlen;
if (len > *lenp)
len = *lenp;
if (len)
if(copy_to_user(buffer, table->data, len))
if(copy_to_user(buffer, data, len))
return -EFAULT;
if (len < *lenp) {
if(put_user('\n', ((char __user *) buffer) + len))
......@@ -1691,6 +1673,31 @@ int proc_dostring(ctl_table *table, int write, struct file *filp,
return 0;
}
/**
* proc_dostring - read a string sysctl
* @table: the sysctl table
* @write: %TRUE if this is a write to the sysctl file
* @filp: the file structure
* @buffer: the user buffer
* @lenp: the size of the user buffer
* @ppos: file position
*
* Reads/writes a string from/to the user buffer. If the kernel
* buffer provided is not large enough to hold the string, the
* string is truncated. The copied string is %NULL-terminated.
* If the string is being read by the user process, it is copied
* and a newline '\n' is added. It is truncated if the buffer is
* not large enough.
*
* Returns 0 on success.
*/
int proc_dostring(ctl_table *table, int write, struct file *filp,
void __user *buffer, size_t *lenp, loff_t *ppos)
{
return _proc_do_string(table->data, table->maxlen, write, filp,
buffer, lenp, ppos);
}
/*
* Special case of dostring for the UTS structure. This has locks
* to observe. Should this be in kernel/sys.c ????
......
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