[added,to,the,4.1,stable,tree] kdb: Fix handling of kallsyms_symbol_next() return value

Message ID 20180118205908.3220-161-alexander.levin@microsoft.com
State New
Headers show
Series
  • [added,to,the,4.1,stable,tree] kdb: Fix handling of kallsyms_symbol_next() return value
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Commit Message

Sasha Levin Jan. 18, 2018, 9 p.m.
From: Daniel Thompson <daniel.thompson@linaro.org>


This patch has been added to the  stable tree. If you have any
objections, please let us know.

-- 
2.11.0

Patch

===============

[ Upstream commit c07d35338081d107e57cf37572d8cc931a8e32e2 ]

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>
Cc: linux-stable <stable@vger.kernel.org>
Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
---
 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 fc1ef736253c..77777d918676 100644
--- a/kernel/debug/kdb/kdb_io.c
+++ b/kernel/debug/kdb/kdb_io.c
@@ -349,7 +349,7 @@  static char *kdb_read(char *buffer, size_t bufsize)
 			}
 			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';