hvsi: fix messed up error checking getting state name

Handle out-of-range indices before reading what they refer to.  And don't
access the one-past-the-end element of the array either.

Signed-off-by: Phil Carmody <ext-phil.2.carmody@nokia.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Roel Kluin <roel.kluin@gmail.com>
Cc: Grant Likely <grant.likely@secretlab.ca>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/drivers/char/hvsi.c b/drivers/char/hvsi.c
index 793b236..d4b14ff 100644 (file)
--- a/drivers/char/hvsi.c
+++ b/drivers/char/hvsi.c
@@ -194,10 +194,8 @@ static inline void print_state(struct hvsi_struct *hp)
                "HVSI_WAIT_FOR_MCTRL_RESPONSE",
                "HVSI_FSP_DIED",
        };
                "HVSI_WAIT_FOR_MCTRL_RESPONSE",
                "HVSI_FSP_DIED",
        };

-       const char *name = state_names[hp->state];
-
-       if (hp->state > ARRAY_SIZE(state_names))
-               name = "UNKNOWN";
+       const char *name = (hp->state < ARRAY_SIZE(state_names))
+               ? state_names[hp->state] : "UNKNOWN";

 
        pr_debug("hvsi%i: state = %s\n", hp->index, name);
 #endif /* DEBUG */
 
        pr_debug("hvsi%i: state = %s\n", hp->index, name);
 #endif /* DEBUG */