params: don't hand NULL values to param.set callbacks.

An audit by Dongdong Deng revealed that most driver-author-written param
calls don't handle val == NULL (which happens when parameters are specified
with no =, eg "foo" instead of "foo=1").

The only real case to use this is boolean, so handle it specially for that
case and remove a source of bugs for everyone else.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Cc: Dongdong Deng <dongdong.deng@windriver.com>
Cc: Américo Wang <xiyou.wangcong@gmail.com>
This commit is contained in:
Rusty Russell 2010-08-11 23:04:10 -06:00
parent d2800800d7
commit 2e9fb9953d
1 changed files with 3 additions and 17 deletions

View File

@ -58,6 +58,9 @@ static int parse_one(char *param,
/* Find parameter */ /* Find parameter */
for (i = 0; i < num_params; i++) { for (i = 0; i < num_params; i++) {
if (parameq(param, params[i].name)) { if (parameq(param, params[i].name)) {
/* Noone handled NULL, so do it here. */
if (!val && params[i].set != param_set_bool)
return -EINVAL;
DEBUGP("They are equal! Calling %p\n", DEBUGP("They are equal! Calling %p\n",
params[i].set); params[i].set);
return params[i].set(val, &params[i]); return params[i].set(val, &params[i]);
@ -181,7 +184,6 @@ int parse_args(const char *name,
tmptype l; \ tmptype l; \
int ret; \ int ret; \
\ \
if (!val) return -EINVAL; \
ret = strtolfn(val, 0, &l); \ ret = strtolfn(val, 0, &l); \
if (ret == -EINVAL || ((type)l != l)) \ if (ret == -EINVAL || ((type)l != l)) \
return -EINVAL; \ return -EINVAL; \
@ -203,12 +205,6 @@ STANDARD_PARAM_DEF(ulong, unsigned long, "%lu", unsigned long, strict_strtoul);
int param_set_charp(const char *val, struct kernel_param *kp) int param_set_charp(const char *val, struct kernel_param *kp)
{ {
if (!val) {
printk(KERN_ERR "%s: string parameter expected\n",
kp->name);
return -EINVAL;
}
if (strlen(val) > 1024) { if (strlen(val) > 1024) {
printk(KERN_ERR "%s: string parameter too long\n", printk(KERN_ERR "%s: string parameter too long\n",
kp->name); kp->name);
@ -309,12 +305,6 @@ static int param_array(const char *name,
kp.arg = elem; kp.arg = elem;
kp.flags = flags; kp.flags = flags;
/* No equals sign? */
if (!val) {
printk(KERN_ERR "%s: expects arguments\n", name);
return -EINVAL;
}
*num = 0; *num = 0;
/* We expect a comma-separated list of values. */ /* We expect a comma-separated list of values. */
do { do {
@ -381,10 +371,6 @@ int param_set_copystring(const char *val, struct kernel_param *kp)
{ {
const struct kparam_string *kps = kp->str; const struct kparam_string *kps = kp->str;
if (!val) {
printk(KERN_ERR "%s: missing param set value\n", kp->name);
return -EINVAL;
}
if (strlen(val)+1 > kps->maxlen) { if (strlen(val)+1 > kps->maxlen) {
printk(KERN_ERR "%s: string doesn't fit in %u chars.\n", printk(KERN_ERR "%s: string doesn't fit in %u chars.\n",
kp->name, kps->maxlen-1); kp->name, kps->maxlen-1);