The call to kmalloc_obj(observed.lines) returns "char (*)[3][512]",
a pointer to the whole 2D array. But "expect" wants to be "char (*)[512]",
the decayed pointer type, as if it were observed.lines itself (though
without the "3" bounds). This produces the following build error:
../kernel/kcsan/kcsan_test.c: In function '__report_matches':
../kernel/kcsan/kcsan_test.c:171:16: error: assignment to 'char (*)[512]' from
incompatible pointer type 'char (*)[3][512]'
[-Wincompatible-pointer-types]
171 | expect = kmalloc_obj(observed.lines);
| ^
Instead of changing the "expect" type to "char (*)[3][512]" and
requiring a dereference at each use (e.g. "(expect*)[0]"), just
explicitly cast the return to the desired type.
Tested with:
$ ./tools/testing/kunit/kunit.py run \
--kconfig_add CONFIG_DEBUG_KERNEL=y \
--kconfig_add CONFIG_KCSAN=y \
--kconfig_add CONFIG_KCSAN_KUNIT_TEST=y \
--arch=x86_64 --qemu_args '-smp 2' kcsan
Reported-by: Nathan Chancellor <[email protected]>
Fixes: 69050f8d6d07 ("treewide: Replace kmalloc with kmalloc_obj for non-scalar
types")
Signed-off-by: Kees Cook <[email protected]>
---
Cc: Marco Elver <[email protected]>
Cc: Dmitry Vyukov <[email protected]>
Cc: <[email protected]>
---
kernel/kcsan/kcsan_test.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/kernel/kcsan/kcsan_test.c b/kernel/kcsan/kcsan_test.c
index 79e655ea4ca1..ae758150ccb9 100644
--- a/kernel/kcsan/kcsan_test.c
+++ b/kernel/kcsan/kcsan_test.c
@@ -168,7 +168,7 @@ static bool __report_matches(const struct expect_report *r)
if (!report_available())
return false;
- expect = kmalloc_obj(observed.lines);
+ expect = (typeof(expect))kmalloc_obj(observed.lines);
if (WARN_ON(!expect))
return false;
--
2.34.1
