kdb: Fix handling of kallsyms_symbol_next() return value

commit c07d35338081d107e57cf37572d8cc931a8e32e2 upstream.

kallsyms_symbol_next() returns a boolean (true on success). Currently
kdb_read() tests the return value with an inequality that
unconditionally evaluates to true.

This is fixed in the obvious way and, since the conditional branch is
supposed to be unreachable, we also add a WARN_ON().

Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Daniel Thompson <daniel.thompson@linaro.org>
Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/kernel/debug/kdb/kdb_io.c b/kernel/debug/kdb/kdb_io.c
index fc1ef736253c79954686d018a2deca4c86300fa6..77777d91867696484e09fef5f4302e1987f98139 100644 (file)
--- a/kernel/debug/kdb/kdb_io.c
+++ b/kernel/debug/kdb/kdb_io.c
@@ -349,7 +349,7 @@ poll_again:
                        }
                        kdb_printf("\n");
                        for (i = 0; i < count; i++) {
-                               if (kallsyms_symbol_next(p_tmp, i) < 0)
+                               if (WARN_ON(!kallsyms_symbol_next(p_tmp, i)))
                                        break;
                                kdb_printf("%s ", p_tmp);
                                *(p_tmp + len) = '\0';