kmemcheck: Test the full object in kmemcheck_is_obj_initialized()
This is a fix for bug #14845 (bugzilla.kernel.org). The update_checksum()
function in mm/kmemleak.c calls kmemcheck_is_obj_initialised() before scanning
an object. When KMEMCHECK_PARTIAL_OK is enabled, this function returns true.
However, the crc32_le() reads smaller intervals (32-bit) for which
kmemleak_is_obj_initialised() may be false leading to a kmemcheck warning.
Note that kmemcheck_is_obj_initialized() is currently only used by
kmemleak before scanning a memory location.
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Christian Casteyde <casteyde.christian@free.fr>
Cc: Vegard Nossum <vegardno@ifi.uio.no>
Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>
diff --git a/arch/x86/mm/kmemcheck/shadow.c b/arch/x86/mm/kmemcheck/shadow.c
index 3f66b82..aec1242 100644
--- a/arch/x86/mm/kmemcheck/shadow.c
+++ b/arch/x86/mm/kmemcheck/shadow.c
@@ -125,12 +125,12 @@
enum kmemcheck_shadow kmemcheck_shadow_test(void *shadow, unsigned int size)
{
+#ifdef CONFIG_KMEMCHECK_PARTIAL_OK
uint8_t *x;
unsigned int i;
x = shadow;
-#ifdef CONFIG_KMEMCHECK_PARTIAL_OK
/*
* Make sure _some_ bytes are initialized. Gcc frequently generates
* code to access neighboring bytes.
@@ -139,13 +139,25 @@
if (x[i] == KMEMCHECK_SHADOW_INITIALIZED)
return x[i];
}
+
+ return x[0];
#else
+ return kmemcheck_shadow_test_all(shadow, size);
+#endif
+}
+
+enum kmemcheck_shadow kmemcheck_shadow_test_all(void *shadow, unsigned int size)
+{
+ uint8_t *x;
+ unsigned int i;
+
+ x = shadow;
+
/* All bytes must be initialized. */
for (i = 0; i < size; ++i) {
if (x[i] != KMEMCHECK_SHADOW_INITIALIZED)
return x[i];
}
-#endif
return x[0];
}