Don't make a temporary copy of fixed sysctl strings.

This commit is contained in:
mjg 2014-07-10 21:46:57 +00:00
parent d284902e11
commit 7ee53e6bf4

View File

@ -1216,26 +1216,33 @@ int
sysctl_handle_string(SYSCTL_HANDLER_ARGS)
{
size_t outlen;
int error = 0;
int error = 0, ro_string = 0;
/*
* A zero-length buffer indicates a fixed size read-only
* string:
*/
if (arg2 == 0)
if (arg2 == 0) {
arg2 = strlen((char *)arg1) + 1;
ro_string = 1;
}
if (req->oldptr != NULL) {
char *tmparg;
/* try to make a coherent snapshot of the string */
tmparg = malloc(arg2, M_SYSCTLTMP, M_WAITOK);
memcpy(tmparg, arg1, arg2);
if (ro_string) {
tmparg = arg1;
} else {
/* try to make a coherent snapshot of the string */
tmparg = malloc(arg2, M_SYSCTLTMP, M_WAITOK);
memcpy(tmparg, arg1, arg2);
}
outlen = strnlen(tmparg, arg2 - 1) + 1;
error = SYSCTL_OUT(req, tmparg, outlen);
free(tmparg, M_SYSCTLTMP);
if (!ro_string)
free(tmparg, M_SYSCTLTMP);
} else {
outlen = strnlen((char *)arg1, arg2 - 1) + 1;
error = SYSCTL_OUT(req, NULL, outlen);