lkdtm: remove intentional off-by-one array access

There wasn't a good reason for keeping the enum and the names out of sync
by 1 position just to avoid "NONE" and "INVALID" from being in the string
lists.

Signed-off-by: Kees Cook <keescook@chromium.org>

diff --git a/drivers/misc/lkdtm_core.c b/drivers/misc/lkdtm_core.c
index e0f1013..4f9d2f3 100644 (file)
--- a/drivers/misc/lkdtm_core.c
+++ b/drivers/misc/lkdtm_core.c
@@ -111,6 +111,7 @@ enum ctype {
 };
 
 static char* cp_name[] = {
+       "INVALID",
        "INT_HARDWARE_ENTRY",
        "INT_HW_IRQ_EN",
        "INT_TASKLET_ENTRY",
@@ -123,6 +124,7 @@ static char* cp_name[] = {
 };
 
 static char* cp_type[] = {
+       "NONE",
        "PANIC",
        "BUG",
        "WARNING",
@@ -257,7 +259,7 @@ static enum ctype parse_cp_type(const char *what, size_t count)
 
        for (i = 0; i < ARRAY_SIZE(cp_type); i++) {
                if (!strcmp(what, cp_type[i]))
-                       return i + 1;
+                       return i;
        }
 
        return CT_NONE;
@@ -266,9 +268,9 @@ static enum ctype parse_cp_type(const char *what, size_t count)
 static const char *cp_type_to_str(enum ctype type)
 {
        if (type == CT_NONE || type < 0 || type > ARRAY_SIZE(cp_type))
-               return "None";
+               return "NONE";
 
-       return cp_type[type - 1];
+       return cp_type[type];
 }
 
 static const char *cp_name_to_str(enum cname name)
@@ -276,7 +278,7 @@ static const char *cp_name_to_str(enum cname name)
        if (name == CN_INVALID || name < 0 || name > ARRAY_SIZE(cp_name))
                return "INVALID";
 
-       return cp_name[name - 1];
+       return cp_name[name];
 }
 
 
@@ -304,9 +306,13 @@ static int lkdtm_parse_commandline(void)
        if (cptype == CT_NONE)
                return -EINVAL;
 
+       /* Refuse INVALID as a selectable crashpoint name. */
+       if (!strcmp(cpoint_name, "INVALID"))
+               return -EINVAL;
+
        for (i = 0; i < ARRAY_SIZE(cp_name); i++) {
                if (!strcmp(cpoint_name, cp_name[i])) {
-                       cpoint = i + 1;
+                       cpoint = i;
                        return 0;
                }
        }