When compiling arm64 allmodconfig with gcc 10.2.1 I get
drivers/crypto/caam/desc_constr.h: In function ‘append_data.constprop’:
include/linux/fortify-string.h:57:29: error: argument 2 null where non-null expected [-Werror=nonnull]
Fix this by skipping the memcpy if data is NULL and add a BUG_ON instead
that triggers on a problematic call that is now prevented to trigger.
After data == NULL && len != 0 is known to be false, logically
if (len)
memcpy(...)
could be enough to know that memcpy is not called with dest=NULL, but
gcc doesn't seem smart enough for that conclusion. gcc 12 doesn't have a
problem with the original code.
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@xxxxxxxxxxxxxx>
---
drivers/crypto/caam/desc_constr.h | 8 +++++++-
1 file changed, 7 insertions(+), 1 deletion(-)
diff --git a/drivers/crypto/caam/desc_constr.h b/drivers/crypto/caam/desc_constr.h
index 62ce6421bb3f..163e0e740b11 100644
--- a/drivers/crypto/caam/desc_constr.h
+++ b/drivers/crypto/caam/desc_constr.h
@@ -163,7 +163,13 @@ static inline void append_data(u32 * const desc, const void *data, int len)
{
u32 *offset = desc_end(desc);
- if (len) /* avoid sparse warning: memcpy with byte count of 0 */
+ /*
+ * avoid sparse warning: "memcpy with byte count of 0" and
+ * and "error: argument 2 null where non-null expected
+ * [-Werror=nonnull]" with fortify enabled.
+ */
+ BUG_ON(data == NULL && len != 0);
+ if (len && data)
memcpy(offset, data, len);
(*desc) = cpu_to_caam32(caam32_to_cpu(*desc) +
base-commit: 9d2f6060fe4c3b49d0cdc1dce1c99296f33379c8
--
2.30.2
