[PATCH] kdb: Fix handling of kallsyms_symbol_next() return value

[PATCH] kdb: Fix handling of kallsyms_symbol_next() return value

[Daniel Thompson]

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>
---
 kernel/debug/kdb/kdb_io.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/kernel/debug/kdb/kdb_io.c b/kernel/debug/kdb/kdb_io.c
index fc1ef73..77777d9 100644
--- 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';
--
2.1.0

Re: [PATCH] kdb: Fix handling of kallsyms_symbol_next() return value

[Jason Wessel]

On 03/02/2015 08:13 AM, Daniel Thompson wrote:
> 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().
> 


Thanks.  Applied to kgdb-next.  I'll send it along to the upstream
before the end of the v4.0 cycle, we'll see if we pickup any other
fixes along the way. :-)

Cheers,
Jason.