selftests: coredump: Properly initialize pointer

The buffer pointer "line" is not initialized. This pointer is passed to
getline().

It can still work if the stack is zero-initialized, because getline() can
work with a NULL pointer as buffer.

But this is obviously broken. This bug shows up while running the test on a
riscv64 machine.

Fix it by properly initializing the pointer.

Fixes: 15858da53542 ("selftests: coredump: Add stackdump test")
Signed-off-by: Nam Cao <namcao@linutronix.de>
Link: https://lore.kernel.org/4fb9b6fb3e0040481bacc258c44b4aab5c4df35d.1744383419.git.namcao@linutronix.de
Signed-off-by: Christian Brauner <brauner@kernel.org>

diff --git a/tools/testing/selftests/coredump/stackdump_test.c b/tools/testing/selftests/coredump/stackdump_test.c
index 137b2364a08207619d9291c16f26acbcc1aa211f..c23cf95c3f6df06279b223ddc3c02160fa445488 100644 (file)
--- a/tools/testing/selftests/coredump/stackdump_test.c
+++ b/tools/testing/selftests/coredump/stackdump_test.c
@@ -138,10 +138,12 @@ TEST_F(coredump, stackdump)
        ASSERT_NE(file, NULL);
 
        /* Step 4: Make sure all stack pointer values are non-zero */
+       line = NULL;
        for (i = 0; -1 != getline(&line, &line_length, file); ++i) {
                stack = strtoull(line, NULL, 10);
                ASSERT_NE(stack, 0);
        }
+       free(line);
 
        ASSERT_EQ(i, 1 + NUM_THREAD_SPAWN);