params: make dashes and underscores in parameter names truly equal

The user may use "foo-bar" for a kernel parameter defined as "foo_bar".
Make sure it works the other way around too.

Apply the equality of dashes and underscores on early_params and __setup
params as well.

The example given in Documentation/kernel-parameters.txt indicates that
this is the intended behaviour.

With the patch the kernel accepts "log-buf-len=1M" as expected.
https://bugzilla.redhat.com/show_bug.cgi?id=744545

Signed-off-by: Michal Schmidt <mschmidt@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> (neatened implementations)
This commit is contained in:
Michal Schmidt 2011-10-10 00:03:37 +02:00 committed by Rusty Russell
parent 37252db6aa
commit b1e4d20cbf
3 changed files with 36 additions and 9 deletions

View file

@ -262,6 +262,26 @@ static inline void __kernel_param_unlock(void)
.str = &__param_string_##name, 0, perm); \
__MODULE_PARM_TYPE(name, "string")
/**
* parameq - checks if two parameter names match
* @name1: parameter name 1
* @name2: parameter name 2
*
* Returns true if the two parameter names are equal.
* Dashes (-) are considered equal to underscores (_).
*/
extern bool parameq(const char *name1, const char *name2);
/**
* parameqn - checks if two parameter names match
* @name1: parameter name 1
* @name2: parameter name 2
* @n: the length to compare
*
* Similar to parameq(), except it compares @n characters.
*/
extern bool parameqn(const char *name1, const char *name2, size_t n);
/* Called on module insert or kernel boot */
extern int parse_args(const char *name,
char *args,

View file

@ -163,7 +163,7 @@ static int __init obsolete_checksetup(char *line)
p = __setup_start;
do {
int n = strlen(p->str);
if (!strncmp(line, p->str, n)) {
if (parameqn(line, p->str, n)) {
if (p->early) {
/* Already done in parse_early_param?
* (Needs exact match on param part).
@ -392,7 +392,7 @@ static int __init do_early_param(char *param, char *val)
const struct obs_kernel_param *p;
for (p = __setup_start; p < __setup_end; p++) {
if ((p->early && strcmp(param, p->str) == 0) ||
if ((p->early && parameq(param, p->str)) ||
(strcmp(param, "console") == 0 &&
strcmp(p->str, "earlycon") == 0)
) {

View file

@ -67,20 +67,27 @@ static void maybe_kfree_parameter(void *param)
}
}
static inline char dash2underscore(char c)
static char dash2underscore(char c)
{
if (c == '-')
return '_';
return c;
}
static inline int parameq(const char *input, const char *paramname)
bool parameqn(const char *a, const char *b, size_t n)
{
unsigned int i;
for (i = 0; dash2underscore(input[i]) == paramname[i]; i++)
if (input[i] == '\0')
return 1;
return 0;
size_t i;
for (i = 0; i < n; i++) {
if (dash2underscore(a[i]) != dash2underscore(b[i]))
return false;
}
return true;
}
bool parameq(const char *a, const char *b)
{
return parameqn(a, b, strlen(a)+1);
}
static int parse_one(char *param,